- cerpch

Imagem de arquivo Voith Hydro
Ano 12 Revista nº 45
ABR/MAI/JUN - 2010
Inovações Tecnológicas em PCHs: destaque para as turbinas hidráulicas
SHP Technological Innovations: Hydraulic turbines under spotlight
OLADE promove, no Paraguai, encontro sobre perspectivas para Energias Renováveis
OLADE holds meeting on the perspectives of renewable energies in Paraguay
IMPRESSO ESPECIAL
Nº 9912253261/2010 DR/MG
Fundação
Theodomiro Santiago
Artigos Técnicos
Technical Articles
Agenda de Eventos
Events Schedule
04
EDITORIAL
A revista PCH Notícias & SHP News aborda, nesta edição, as inovações
In this edition the magazine PCH Notícias & SHP News approaches the
tecnológicas para o mercado, no setor elétrico. Hoje, a indústria nacional es-
technological innovations for the market of the electric sector. Today, the na-
tá qualificada para atender esse mercado em franca expansão, fornecendo
tional industry is qualified to meet the demands of this fast growing market,
parte dos componentes hidromecânicos e elétricos. A indústria brasileira
supplying part of the hydro-mechanical and electrical components. The Bra-
tem condições de atender o mercado interno, produzindo equipamentos co-
zilian industry can satisfy the needs of the internal market, producing equip-
mo comportas, condutos, válvulas, turbinas, geradores, reguladores de velo-
ment such as comportas, condutos, valves, turbines, generators, velocity
cidade, além dos elétricos.
regulators and electrical parts.
Visto essas mudanças no setor, as universidades nacionais estão inves-
According to these changes in the sector, the national universities are in-
tindo na qualificação de novos profissionais por entender que a capacitação
vesting in the qualification of new professionals due to their understanding
da mão de obra nacional é importante para o crescimento do país, além de
that the qualification of the national labor is importance for the growth of the
gerar um profissional qualificado, o que reduz custos de contratação de pro-
country. This also reduces the costs of having to hire specialist abroad.
fissionais no exterior.
We also followed the workshop, carried out by the Mechanic Engineering
Nessa edição acompanhamos, o workshop realizado pelo Instituto de
Institute of the Federal University of Itajubá – UNIFEI, about the methods of
Engenharia Mecânica (IEM) da Universidade Federal de Itajubá (UNIFEI) so-
Computational fluid dynamics and the meeting promoted by OLADE, in Para-
bre métodos de dinâmica dos fluidos computacional (CFD) e o encontro pro-
guay, on renewable energy perspectives.
movido pela OLADE, no Paraguai, sobre perspectivas para Energias Renováveis.
From this edition on, there will be a special segment for our readers,
where you can give your opinions and suggestions, ask questions, etc.
Destacamos, ainda, que a partir dessa edição estaremos com um espaço
I would also like to invite you all to participate with us in the 6th Meeting
destinado aos nossos leitores. Nele, os leitores poderão tirar suas dúvidas,
on SHP, Market & Environment that will be in São Paulo on September 1st
dar opiniões, fazer sugestões, etc.
and 2nd. For more information: www.conferenciadepch.com.br.
Aproveito a oportunidade para convidar a todos nossos leitores para que
participem conosco de nossa 6ª Conferência de PCH, Mercado & Meio Ambi-
Geraldo Lúcio Tiago Filho.
ente que será realizada nos dias 1 e 2 de setembro, em São Paulo. Mais informações podem ser obtidas no site: www.conferenciadepch.com.br.
Geraldo Lúcio Tiago Filho.
APOIO:
Ministério de
Minas e Energia
03
Comitê Diretor do CERPCH
Director Committee
Geraldo Lúcio Tiago Filho
Secretário Executivo
[email protected]
Gilberto Moura Valle Filho
CEMIG
[email protected]
Patrícia Cristina P. Silva
FAPEPE
[email protected]
Célio Bermann
IEE/USP
[email protected]
Cláudio G. Branco da Motta
FURNAS
[email protected]
José Carlos César Amorim
Editorial
Editorial
03
IME
[email protected]
Antonio Marcos Rennó Azevedo
Eletrobrás
[email protected]
Jamil Abid
ANEEL
[email protected]
Hamiltom Moss
MME
[email protected]
Comitê Editorial
Editorial Committee
Presidente - President
Geraldo Lúcio Tiago Filho - CERPCH UNIFEI
Editores Associados - Associated Publishers
Adair Matins - UNCOMA - Argentina
Alexander Gajic – University of Serbia
Alexandre Kepler Soares - UFMT
Ângelo Rezek - ISEE UNIFEI
Antônio Brasil Jr. - UNB
Artur de Souza Moret - UNIR
Augusto Nelson Carvalho Viana - IRN UNIFEI
Bernhard Pelikan - Bodenkultur Wien – Áustria
Carlos Barreira Martines - UFMG
Célio Bermann - IEE USP
Edmar Luiz Fagundes de Almeira - UFRJ
Fernando Monteiro Figueiredo - UNB
Frederico Mauad – USP
Helder Queiroz Pinto Jr. - UFRJ
Jaime Espinoza - USM - Chile
José Carlos César Amorim - IME
Marcelo Marques - IPH UFRGS
Marcos Aurélio V. de Freitas - COPPE UFRJ
Maria Inês Nogueira Alvarenga - IRN UNIFEI
Orlando Aníbal Audisio - UNCOMA - Argentina
Osvaldo Livio Soliano Pereira - UNIFACS
Zulcy de Souza - LHPCH UNIFEI
Inovações Tecnológicas
Technological Innovations
Inovações Tecnológicas em PCHs: destaque para as turbinas hidráulicas
SHP Technological Innovations: Hydraulic turbines under spotlight
Curtas
News
10
OLADE promove, no Paraguai, encontro sobre perspectivas para Energias
Renováveis
OLADE holds meeting on the perspectives of renewable energies in Paraguay
Unifei realiza workshop sobre CFD
Unifei Carries Out Workshop on CFD
Artigos Técnicos
Technical Articles
Schedule
Geraldo Lúcio Tiago Filho
Camila Rocha Galhardo
Adriana Barbosa MTb-MG 05984
Adriana Barbosa
Camila Rocha Galhardo
Fabiana Gama Viana
Projeto Gráfico
Diagramação e Arte
Net Design
Adriano Silva Bastos
Cidy Sampaio da Silva
Tradução
Opinião
Opinion
33
34
A Inovação Tecnológica nas Fontes Alternativas
Technological Innovations for Alternative sources of Energy
Meio Ambiente e Inovação em PCHs
Environment and SHP Innovation
Adriana Candal
PCH Notícias & SHP News
é uma publicação trimestral do CERPCH
The PCH Notícias & SHP News
is a three-month period publication made by CERPCH
Tiragem/Edition: 5.800 exemplares/issues
contato comercial: [email protected]
Av. BPS, 1303 - Bairro Pinheirinho
Itajubá - MG - Brasil - cep: 37500-903
e-mail: [email protected]
[email protected]
Fax/Tel: (+55 35) 3629 1443
ISSN 1676-0220
00045
9 771676 022092
04
13
Agenda
Expediente
Editorial
Editor
Coord. Redação
Jornalista Resp.
Redação
06
Espaço do Leitor
Readers space
40
INOVAÇÕES TECNOLÓGICAS
Inovações Tecnológicas em PCHs:
destaque para as turbinas hidráulicas
Por Fabiana Gama Viana
A energia hidráulica representa a maior aplicação das fontes renováveis no mundo e é a que possui tecnologias mais maduras e consolidadas. Do total de energia elétrica produzida no mundo, 15,6% são oriundas da energia hidráulica (BEN 2009, dados de 2007).
Países como China e Canadá estão realizando grandes esforços para o desenvolvimento e aperfeiçoamento das PCHs. O mesmo acontece com países africanos e da América do Sul, os quais também possuem grande potencial ainda não aproveitado para a implantação dos
pequenos aproveitamentos hidroenergéticos. De acordo com o relatório Evolução Tecnológica das PCHs no Brasil, publicado pelo Centro
Nacional de Referência em PCHs (CERPCH), 33% do potencial hidrelétrico mundial tecnicamente factível já foram explorados. Europa e
América do Norte já desenvolveram praticamente todo o seu potencial, restando cerca de 70% a serem explorados na América do Sul, África e Ásia.
No Brasil, o Plano Nacional de Energia (PNE 2030), publicado pelo Ministério de Minas e Energia em 2008, aponta que, em 2030, a potência instalada a partir da energia hidráulica será de 88.200 MW, indicando um aumento de 28,57% em comparação com dados de 2005.
O PNE 2030 ainda prevê o aumento do potencial de PCHs, sendo incluídos mais 6.000 MW ao sistema. Da mesma forma, o plano aponta
que, em 2030, as pequenas centrais hidrelétricas terão um potencial de 8.242 MW a ser aproveitado, indicando um nicho de mercado com
grandes perspectivas.
Aliado a isso, nos últimos anos, houve um interesse crescente dos grandes consumidores na livre negociação de energia, e as PCHs
passaram a ser oportunidades de maximizar a eficiência dos processos produtivos, reduzindo os custos de produção. Da mesma forma, os
incentivos regularórios, a viabilidade econômica, o baixo impacto ambiental, os programas de incentivo governamentais e o grande potencial de expansão previsto para as próximas décadas fazem com que as PCHs sejam objeto de grande interesse por parte do mercado, o
que vem a ser comprovado pelo aumento do número de pequenas centrais no Brasil, pelo crescimento de empresas ligadas ao setor e pela
reestruturação dos tradicionais fabricantes de equipamentos.
INDÚSTRIA NACIONAL DE PCHs
vação do meio ambiente norteiam a indústria de equipamentos no
A indústria nacional está qualificada para atender esse mercado
que diz respeito a inovações tecnológicas em PCHs. Nesse sentido,
em franca expansão, fornecendo parte dos componentes hidrome-
a escolha da turbina é indispensável para o bom rendimento da cen-
cânicos e elétricos. Hoje, a indústria brasileira tem condições de
tral, devendo ser feita de acordo com a altura útil da queda, a vazão
atender o mercado interno, produzindo equipamentos como com-
e sua velocidade específica. Turbinas como Michell-Banki, Pelton,
portas, condutos, válvulas, turbinas, geradores, reguladores de ve-
Francis, Hélice e Kaplan, fabricadas pela indústria nacional, pratica-
locidade, além dos elétricos.
mente atendem o mercado de mini, micro e pequenas centrais hi-
De acordo com o relatório "Estudo do Potencial de Mercado das
Fontes Renováveis Alternativas no Brasil", publicado em 2005 pelo
drelétricas.
Antonio Carlos Bettarello, proprietário da Betta Hidroturbinas,
Núcleo Interdisciplinar de Planejamento Energético (NIPE) da Uni-
empresa
camp a partir de convênio com a FINEP/FUNCATE/INT, as grandes
hidrelétricas, aponta o aumento do rendimento das turbinas
empresas, na maioria dos casos, contam com a tecnologia de em-
hidráulicas, decorrente da utilização de modelos computacionais,
presas estrangeiras, tendo condições de competir no fornecimento
como um dos destaques no que diz respeito às inovações em
de equipamentos com potências acima de 5 MW. No que diz respeito
pequenos aproveitamentos hidroenergéticos. “Essas ferramentas
a potências menores, o mercado de PCHs acaba sendo atendido por
possibilitaram em curtíssimo espaço de tempo ensaiar várias
empresas nacionais de pequeno porte.
alterações de projeto e rapidamente chegar a excelentes resultados
fabricante
de
equipamentos
para
microcentrais
com um custo muito baixo”, explica.
DESTAQUE PARA AS TURBINAS HIDRÁULICAS
A necessidade de desenvolver equipamentos com bom rendimento para usinas com características específicas aliada à conser-
06
Roberto Miranda, Diretor de Desenvolvimento de Negócios da
Alstom Power Generation, multinacional francesa fabricante de equipamentos, também destaca a importância da chegada no Brasil de
TECHNOLOGICAL INNOVATIONS
SHP Technological Innovations:
hydraulic turbines under spotlight
Translation Adriana Candal
Hydraulic energy represents the largest use of renewable sources in the world and it is the one that has more mature and consolidated
technologies. Out of the total amount of electric power produced worldwide, 15.6% come from hydraulic energy (BEN 2009, data from
2007).
Countries such as China and Canada have been working hard to develop and improve Small Hydropower Plants (SHPs). The same has
been taking place in African and South American countries, which also have a huge potential that has not been used for the implementation of SHPs. According to the report Technological Evolution of SHPs in Brazil, published by CERPCH (National Reference Center for Small
Hydropower CERPCH) 33% of the world's hydropower potential that is technically viable has already been explored. Europe and North
America have practically developed all of their potential, but there are about 70% to be used in South America, Africa and Asia.
In Brazil, the National Energy Plan (PNE 2030), published by the Ministry of Mines and Energy in 2008, points out that in 2030 the installed potential based on hydropower will be 88,200 MW, indicating a rise of 28.57% in comparison with data from 2005. The PNE 2030 also forecasts the rise in the SHP potential, which will add more than 6,000 MW to the system. In the same way, the Plan indicates that in
2030 the SHPs will have a potential of 8,242 MW to be used, indicating a market niche with great perspectives.
Also, over the past few years, there was a growing interest of the consumers in the free energy trading, and the SHPs became an opportunity of maximizing the efficiency of the productive processes, reducing the production costs. In the same way, the regulatory encouragements, the economic feasibility, the low environmental impact, the governmental encouragement programs and the huge expansion
potential forecast for the next decades made SHPs an attractive object in the market, which is confirmed by the rise in the number of SHPs
in Brazil, by the growth of the companies in this sector and by the re-structuring of traditional equipment manufacturers.
SHP NATIONAL INDUSTRY
excellent results at considerable low costs”, he explains.
The national industry is qualified to meet the demand of this fast
Mr. Roberto Miranda, director of business development of
growing market, supplying part of the hydro-mechanical and elec-
Alstom Power Generation, a French multinational that manufactu-
trical components. Today the Brazilian industry can meet the needs
res equipment, also highlights the importance of the arrival of new
of the internal market producing equipment such as dams, valves,
hydraulic turbines technologies in Brazil over the past 15 years,
turbines, generators, velocity regulators and the electrical compo-
which can produce new optimized arrangements of SHPs. Mr. Miran-
nents.
da mentions the horizontal Francis-like turbines and the Kaplan tur-
According to the report "Study of the Market Potential of Renewable Alternative Sources of Energy in Brazil”, published in 2005 by
bines (especially the S and the Pit types), i.e., equipment that have
broken the traditional SHP systems of using vertical turbines.
the Interdisciplinary Center of Energy Planning (NIPE) of the Uni-
Francis turbines are reactions machines (the rotor is completely
versity of Campinas (UNICAMP) through partnerships with
under water). They have radial flow (slow and normal) and mixed
FINEP/FUNCATE/INT, the large companies, in most cases, rely on
flow (fast), which operate at medium flows and medium heads. The
the technology of foreign companies, having conditions to measure
control of the flow is carried out in the distributor or in by a system
up the supply of equipment with powers higher than 5 MW. As far as
of moving blades. The horizontal Francis turbines are the ones who-
lower powers are concerned, the SHP market ends up being suppli-
se axis is assembled in a horizontal position. As a result, civil works
ed by small-scaled national enterprises.
are usually cheaper due to smaller volumes of excavation and concrete. However, when the power and the flow of the machine increa-
HYDRAULIC TURBINES IN THE SPOTLIGHT
se, some problems start to appear, or even impediments, due to the
The need to develop equipment with good efficiency for plants
mechanical endurance of the axis. Then, the vertical axis machines
with specific characteristics and the conservation of the environ-
start to be used.
ment guide the equipment industry in relation to technology inno-
The Kaplan turbines are also reaction machines of axial flow that
vations concerning SHPs. In this sense, the choice of the turbine is
operate with large flows and low heads. The difference between
indispensable for the good efficiency of the plant, and it must be car-
Kaplan-like and the Francis-like turbines is the rotor. In the case of
ried out according to the net height of the head, the flow and its spe-
Kaplan-like machines, it is similar to a helix, as a ship propeller. The
cific velocity. Turbines such as Michell-Banki, Pelton, Francis, Pro-
S-like, the bulb-like and the Pit-like turbines are derivations of the
peller and Kaplan, manufactured by the national industry, practi-
Kaplan.
cally meet the market of mini, micro and small hydropower plants.
Horizontal S type machines are appropriate for low head poten-
Mr. Antonio Carlos Bettarello, the owner of Betta Hidroturbinas,
tials, between 5m and 20m, sometimes even higher. They are com-
a company that manufactures equipment for micro hydropower
monly used in Small Hydropower Plant projects because they are
plants, points out the rise in the hydraulic turbines, due to the use of
simple to operate and assemble and have easy access and mainte-
computational models, as one of the highlights in the innovations
nance.
for SHPs. “These tools enabled the simulation of several changes in
Mr. Miranda highlights that this type of turbines, manufactured
the project in a very short period of time, making it possible to reach
by Alstom, are the best ones for low head SHPs with a unit power up
07
INOVAÇÕES TECNOLÓGICAS
novas tecnologias de turbinas hidráulicas nos últimos 15 anos, capa-
risco aos peixes, especialmente em períodos de grandes desloca-
zes de produzir arranjos otimizados de pequenas centrais hidrelétri-
mentos dos cardumes na piracema, período no qual buscam áreas
cas. Miranda menciona as turbinas tipo Francis horizontal e as da Fa-
com maior volume de água, que correspondem exatamente às saí-
mília Kaplan (tipo S e Poço, em especial), ou seja, equipamentos
das das turbinas. Por uma mudança abrupta da pressão, turbulên-
que romperam o sistema tradicional dos aproveitamentos hidrelé-
cia e impactos mecânicos, certa quantidade de peixes não sobrevi-
tricos de usarem turbinas verticais.
ve à passagem pelas turbinas. Nesse sentido, diferentes tipos de
As turbinas Francis são máquinas de reação (o rotor é completamente submergido na água), escoamento radial (lenta e normal) e
equipamentos e métodos inovadores são desenvolvidos para mitigar esse problema.
misto (rápida), que operam em médias vazões e médias quedas. O
As grades ou grelhas anti-lixo têm a função de evitar que tron-
controle da vazão é realizado no distribuidor ou sistema de pás mó-
cos, galhos, folhas e lixos passem pela turbina, podendo obstruir e
veis. As turbinas Francis horizontais são aquelas nas quais o eixo es-
até mesmo ocasionar danos ao rotor da mesma. Esse mecanismo
tá montado na posição horizontal. Em função disso resultam nor-
acaba impedindo também que grande parte dos peixes entre na tur-
malmente obras civis mais baratas, função de menores volumes de
bina, mas ainda assim sua mortandade é considerada uma das preo-
escavação e concreto. No entanto quando a potência e vazão da má-
cupações e foco de estudos no aperfeiçoamento de equipamentos
quina aumentam começam a haver problemas, ou mesmo impedi-
para PCHs.
mentos, do ponto de vista da suportabilidade mecânica do eixo. Passam então a ser utilizadas as máquinas de eixo vertical.
A melhoria no design das pás das turbinas é uma solução para reduzir esse problema. As turbinas ecológicas ou fish friendlies turbi-
As turbinas do tipo Kaplan também são máquinas de reação, de
nes, evolução das turbinas de fluxo axial, foram desenvolvidas com
escoamento axial, operando com grandes vazões e baixas quedas.
design para alcançar uma taxa de sobrevivência maior dos peixes
A diferença entre as turbinas Kaplan e a Francis é o rotor. No caso
quando estes passam pela turbina. Da mesma forma, essas turbi-
das máquinas do tipo Kaplan, este é semelhante a um propulsor de
nas são livres de óleos e graxas, eliminando assim o risco de conta-
navio (similar a uma hélice). As turbinas do tipo S, Poço e Bulbo são
minação dos cursos d'água.
derivações da Kaplan.
Além disso, estão sendo estudados e desenvolvidos métodos
As máquinas do tipo horizontal S são adequadas a aproveita-
inovadores e alternativos para a prevenção da entrada de peixes
mentos de baixas quedas, entre 5m e 20m, podendo chegar, em al-
nas turbinas. Como exemplos, a utilização de correntes elétricas,
guns casos, a quedas maiores. São comumente utilizadas em proje-
cortinas de bolhas de ar e ondas sonoras para guiar os peixes para
tos de pequenas centrais hidrelétricas por apresentarem flexibilida-
um caminho longe das entradas das turbinas. Em testes realizados
de de operação, simplicidade de montagem e facilidade de acesso e
no Lago Borreman, na Noruega, em 2007, pôde-se comprovar a efi-
manutenção.
ciência do sistema de ondas sonoras (baixa frequência). Mas essa
Miranda destaca as turbinas desse tipo fabricadas pela Alstom,
que possibilitaram viabilizar PCHs com turbinas de potência unitária
tecnologia ainda precisa ser aperfeiçoada e estudos sobre o comportamento de peixes tropicais necessitam ser realizados.
até 15.000 kW de baixas quedas, especialmente no atendimento
Essas soluções são consideradas para situações mais simples,
aos empreendimentos do Programa de Incentivo às Fontes Renová-
pois correspondem ao movimento de descida dos peixes. A maior di-
veis Alternativas (Proinfa). “Estas turbinas podem, atualmente, atin-
ficuldade é no caminho contrário, ou seja, a subida dos peixes por
gir 25.000 kW de potência unitária e atender quedas de até 40m, o
conta da reprodução. Da mesma forma, na piracema, os peixes bus-
que configura um grande avanço em direção às médias centrais hi-
cam as áreas com maior volume de água, que correspondem exata-
drelétricas”, explica Miranda.
mente às saídas das turbinas. Nesse sentido, são desenvolvidos es-
Já as do tipo Poço são turbinas com aplicação em baixas quedas
tudos para se aprimorar o mecanismo de transposição de peixes
e alta vazão. Elas se caracterizam pela concepção de turbina bulbo
(MTPs). Esses mecanismos constituem de escadas, elevadores ou
com uso de multiplicadores de velocidade.
eclusas que possibilitam aos peixes ultrapassarem a barramento
As máquinas do tipo bulbo operam em quedas abaixo de 20 m e
são similares à turbina Kaplan horizontal. Neste arranjo, o gerador
das usinas e assim atenuar os efeitos negativos no período de reprodução dos peixes.
apresenta-se montado na mesma linha da turbina em posição quase horizontal e envolto por um casulo que o protege do fluxo normal
da água.
OUTROS DESTAQUES
Outras inovações em equipamentos para pequenos aproveita-
As máquinas para centrais de baixa queda são o destaque de Lu-
mentos hidroenergéticos merecem destaque. Antonio Carlos Betta-
iz Fontes, Gerente de PCH da Voith Hydro-Brasil, “joint-venture“ en-
rello, da Betta Hidroturbinas, destaca o avanço na automação, espe-
tre Voith e Siemens na divisão mecânica e elétrica para o forneci-
cialmente nos reguladores de velocidade, que hoje utilizam micro
mento de turbinas e geradores de energia elétrica. Fontes explica
processadores programáveis, encontrados com facilidade no mer-
que a demanda por essas máquinas é crescente e rápida em função
cado.
da redução dos aproveitamentos de maior queda. “Para a viabilida-
O Gerente de PCH da Voith Hydro-Brasil, Luiz Fontes, enfatiza a
de de aproveitamentos de baixa queda, as soluções tecnológicas
utilização do PRFV (plástico reforçado por fibra de vidro) como subs-
quanto a equipamentos e mesmo obras civis merecem maior aten-
tituto dos tradicionais condutos forçados em aço, o que implicou em
ção”, completa.
melhor estudo dos transientes hidráulicos. Os circuitos hidráulicos
longos, a ausência de chaminé de equilíbrio e a operação de centrais
QUESTÃO AMBIENTAL
a partir de centros de operação conectados por Internet ou meio físi-
A instalação de uma turbina em um curso d'água representa um
co também são mencionados por Fontes.
08
Foto: Arquivo Voith Hydro
TECHNOLOGICAL INNOVATIONS
Gerente de PCH da Voith Hydro-Brasil, Luiz Fontes
to 15,000 kW, especially regarding the demand of enterprises that
equipment.
are part of PROINFA (a program encouraging renewable alternati-
The improvement in the design of the blades of the turbines is a
ves of energy). “Today, these turbines may reach 25,000 kW of uni-
solution to reduce this problem. The fish friendly turbines, an evolu-
tary power and be used for heads up to 40m high, which configures
tion of the axial flow turbines, have been developed with a design to
a great advance towards medium hydropower plants”, explains Mr.
reach a higher survivorship rate of the fish that pass through the tur-
Miranda.
bine. In the same way, these turbines are free of oil and grease, eli-
On the other hand, the Pit type turbines are used for low heads
and high flows. They are characterized by the conception of the bulb
units with the use of speed increaser.
minating the risk of contamination of the streams.
In addition, innovating and alternative methods are being studied and developed aiming at preventing the fish from entering the
Bulbo-like machines operate at heads lower than 20 m and are
turbine. As examples it is possible to mention the use of electric cur-
similar to the Kaplan horizontal turbine. In this arrangement the ge-
rents, air bubble curtains and sound waves for guiding the fish away
nerator is assembled in the same line as the turbine, at an almost ho-
from the turbine entrances. Some tests were carried out in Lake Bor-
rizontal position, and it is enclosed by a cocoon that protects it from
reman, Norway, in 2007. It was possible to confirm the efficiency of
the normal water flow.
the sound wave system (low frequency). But this technology still ne-
Machines for low head plants are the highlight of Mr. Luiz Fontes,
SHP Manager of Voith Hydro-Brasil, a joint-venture between Voith
eds to be improved and studies on the behavior of tropical fish must
be carried out.
and Siemens in the mechanic and electric division for the supply of
These solutions are considered for simple situations, for they
electric energy turbines and generators. Mr. Fontes explains that
correspond to the downstream migration of the herding. The grea-
the demand for these machines is growing fast due to the reduction
test difficulty is when the fish go upstream for reproduction. There
in higher heads potentials. “Aiming at the feasibility of low head po-
are ongoing studies on Fish Diversion Mechanisms towards this pro-
tentials, technological solutions regarding equipment and civil
blem. These mechanisms are ladders, elevators or floodgates that
works deserve more attention”, he completes.
enable the fish to jump over the dam of the plants and this way, mitigate the negative effects during the period of reproduction the fish.
ENVIRONMENTAL ISSUE
The installation of a turbine in a stream represents a risk for the
OTHER HIGHLIGHTS
fish, especially during periods of long dislocations due to their mi-
Other equipment innovations for SHPs also deserve to be high-
gration, when they look for area with larger amounts of water, which
lighted. Mr. Antonio Carlos Bettarello, Betta Hidroturbinas, menti-
correspond exactly to the turbine outflow. Because of a sharp chan-
ons the advance in automation, especially on the velocity regula-
ge in pressure, turbulence and mechanical impacts, a certain
tors, which today, use programmable microprocessors that are ea-
amount of fish do not survive passing through the turbines. In this
sily found in the market.
sense, different types of innovating equipment and methods are developed to mitigate these problems.
The SHP manager of Voith Hydro-Brasil, Mr. Luiz Fontes, emphasizes the use of PRFV (glass fiber-reinforced plastic) as a substitute
Screens aim at avoiding that trunks, branches, leaves and de-
for the traditional steel penstock, which provides a better study of
bris pass through the turbine, which may obstruct or even harm the
the hydraulic transients. The long hydraulic circuits, the absence of
rotor. This mechanism ends up by avoiding part of the fish to enter
a surge tower and the operation of plants from operation centers
the turbine, but still, their mortality is considered one of the con-
connected through the Internet or physical means are also mentio-
cerns and focus of studies regarding the improvements in SHP
ned by Mr. Fontes.
09
CURTAS
OLADE promove no Paraguai,
encontro sobre perspectivas para Energias Renováveis
OLADE holds meeting on the
perspectives of renewable energies in Paraguay
Por Adriana Barbosa
Translation Adriana Candal
Especialistas Latino Americanos se reúnem em Assunção, no Pa-
Latin American experts get together in Asunción, Paraguay, to
raguai, para discutir as perspectivas do uso das energias renová-
talk about the perspectives of the use of renewable energy and the
veis e a integração elétrica do Cone Sul da América Latina.
electric integration of the South Cone of South America.
O encontro, realizado entre os dias 26 e 27 de maio, promovido
The meeting, held on May 26th and 27th by the Latinamerican
pela Organização Latino Americana de Energia (OLADE) buscou evi-
Energy Organization (OLADE), aimed at showing the tendencies of
denciar as tendências das indústrias de geração de energia reno-
the industry of renewable energy generation and analyzing the ben-
vável e analisar os benefícios proporcionados por sua aplicação re-
efits provided by their regional and international application, giv-
gional e internacional, além de fornecer exemplos de sua aplica-
ing examples of their application and establishing the challenges re-
ção e bem como estabelecer os desafios referentes à integração
garding the integration of the plants of Itaipu (Brazil/Paraguay)
das usinas de Itaipu (Brasil/Paraguai) e de Yacyretá (Bra-
and Yacyretá (Brazil/Argentina) in the energy integration of the
sil/Argentina) na integração energética do Cone Sul, por meio do
South Cone through Paraguay.
The 1st Regional Workshop on Electricity presents the renew-
Paraguai.
O 1° Workshop Regional sobre Eletricidade apresentou o cená-
able enrgy scenario of the region and discussed the potentialities of
rio energético renovável da região, além de discutir as potenciali-
large scale integration in the South Cone, where some of the larg-
dades de integração em larga escala no Cone Sul, onde estão insta-
est hydropower plants in the world are installed, representing an in-
ladas algumas das maiores usinas hidrelétricas do mundo, repre-
vestment of about US$ 300 million.
sentando um investimento em torno de US$ 300 milhões.
A intenção desse encontro foi buscar opções de projetos para viabilizar a interligação das linhas de transmissão Itaipu à Yacyretá e
The intention of this meeting was to search for project options
to make the interconnection of the power lines Itaipu/Yacyretá and
Villa Hayes/Formosa feasible.
OLADE's Executive Secretary. Mr. Carlos Arturo Flórez
Villa Hayes à Formosa.
A sessão de abertura contou com a presença do Secretá-
Piedrahita, the Vice Minister of Mines and Energy, Ministry of Public
rio Executivo da OLADE, Carlos Arturo Flórez Piedrahita; da Vice Mi-
Works and Communications, MS. Mercedes Canese and the Gen-
nistra de Minas y Energia del Ministerio de Obras Públicas y Comu-
eral Director of Binacional Itaipu, Mr. Gustavo Codas Friedmann
nicación del Paraguay, Mercedes Canese e do Diretor Geral para-
(Paraguay) were present in the opening session.
guaio de Binacional Itaipu,Gustavo Codas Friedmann
O evento contou com a participação de representantes de empresas públicas e privadas, organizações internacionais e especia-
The event also had the participation of public and private company representatives, international organizations and energy experts.
Foto: Tiago Filho
listas em energia.
Cerimônia de abertura do 1° Workshop Regional sobre Eletricidade.
10
NEWS
Unifei realiza workshop sobre CFD
Unifei Carries Out Workshop on CFD
Translation Adriana Candal
Foto: Camila Galhardo
Por Adriana Barbosa
Prof. Dr. Ramiro G. Ramirez Camacho; Prof.Dr. Nelson Manzanares Filho;
Eng. José Biruel Júnior; Prof. Dr. Waldir de Oliveira
O desenvolvimento de metodologias de análise e projeto de tur-
The development of methodologies to analyze and design hy-
binas hidráulicas, utilizando métodos de dinâmica dos fluidos com-
draulic turbines using Computational Fluid Dynamics (CFD) was
putacional (CFD) foi o tema do workshop realizado pelo Instituto
the theme of a workshop carried out by the Mechanic Engineering
de Engenharia Mecânica (IEM) da Universidade Federal de Itajubá
Institute (IEM) of the Federal University of Itajubá in April.
(UNIFEI) realizado em abril.
The workshop aimed at debating the CFD application potential
O workshop objetivou discutir o potencial de aplicação de CFD
in hydraulic turbo machines, identifying the technical obstacles
em turbo máquinas hidráulicas, identificar as barreiras técnicas ao
against the development of the technology, proposing solutions
desenvolvimento da tecnologia, além de propor soluções e identifi-
and identifying new R&D paths.
car novas linhas de P&D.
The university started its researches using CFD methods
A Universidade iniciou as pesquisas utilizando métodos de CFD
through a partnership with Petrobrás for the implementation of the
através do convênio que firmou com a Petrobrás para implantação
Virtual Hydrodynamic Laboratory. In this laboratory, researchers
do Laboratório Hidrodinâmico Virtual. Nele, os pesquisadores coor-
coordinated by professors Nelson Manzanares, Ramiro Ramirez
denados pelos professores Nelson Manzanares, Ramiro Ramirez e
and Waldir de Oliveira widened and consolidated the experience of
Waldir de Oliveira ampliaram e consolidaram a experiência do Gru-
the Fluid Dynamics and Turbo Machines Group of the IEM regarding
po de Dinâmica dos Fluidos e Turbo máquinas do IEM no desenvol-
the development of a reliable and modern technology for the hy-
vimento de uma metodologia confiável e moderna para análise e
drodynamic analysis and design of hydraulic turbines.
projeto hidrodinâmico de turbinas hidráulicas.
During his presentation in the workshop that approached Small
Durante sua apresentação no workshop que abordou as peque-
Hydropower Plants in Petrobrás, engineer José Biruel Junior high-
nas centrais hidrelétricas na Petrobrás o engenheiro, José Biruel Ju-
lighted Petrobrás concern towards improving the productive pro-
nior, ressaltou a preocupação da Petrobrás em melhorar o processo
cess of the company by trying to find partnerships with universities
produtivo da empresa procurando buscar junto às universidades
due to the understanding that the qualification of the national labor
uma parceria, por entender que a capacitação da mão de obra naci-
is important for the growth of the country. Forming qualified pro-
onal é importante para o crescimento do país. Além de gerar um
fessionals reduces the costs of hiring professionals abroad.
profissional qualificado, o que reduz custos de contratação de profissionais no exterior.
Para o professor Nelson Manzanares os profissionais com experiência em dinâmica dos fluidos computacional são rapidamente ab-
For professor Nelson Manzanares professionals experienced in
Computation Fluid Dynamics are fast absorbed by the market and
there is a tendency in the country towards rise in the search for
these professionals.
sorvidos pelo mercado e há uma tendência, no país, de aumentar a
procura por esses profissionais.
11
NUMERICAL STUDY ON THE EFFECT OF IMPELLER TRIMMING ON THE PERFORMANCE AND FLOW CHARACTERISTICS
14
OF A CENTRIFUGAL PUMP WITH VOLUTE-CASING
Raúl Barrio, Eduardo Blanco, Jorge Parrondo, Carlos Santolaria
STRENGTH ANALYSIS OF THE AXIAL FLOW BLADES BASED ON CFD
20
Zheng Xiaobo, Luo Xingqi, Guo Pengcheng
SIMULAÇÃO DO ESCOAMENTO EM UM TUBO D E SUCÇÃO DE UMA MÁQUINA HIDRÁULICA MOTORA COM CONTROLE
TECHNICAL ARTICLES
Technical Articles Seccion
22
DE VAZÃO FEITO POR UM OBTURADOR INSERIDO NA SUA SEÇÃO DE SAÍDA.
Patrícia Santos Tertuliano, Geraldo Lúcio Tiago Filho, Harley Alencar de Souza
THE STUDY OF ACTIVE FLOW CONTROL IN FRANCIS TURBINES
27
Classificação Qualis/Capes
ENGENHARIAS III
INTERDISCIPLINAR
ENGENHARIAS I
B5
ARTIGOS TÉCNICOS
Roland Wunderer, Rudolf Schilling
Áreas de: Recursos Hídricos
Meio Ambiente
Energias Renováveis e não Renováveis
13
ARTIGOS TÉCNICOS
NUMERICAL STUDY ON THE EFFECT OF IMPELLER TRIMMING ON THE
PERFORMANCE AND LOW CHARACTERISTICS OF A CENTRIFUGAL
PUMP WITH VOLUTE-CASING
Raúl Barrio
Eduardo Blanco
Jorge Parrondo
Carlos Santolaria
ABSTRACT
The trimming of the impellers of centrifugal pumps is a usual practice in industry in order to adapt the pump performance features to
the requirements of a specific hydraulic system, but it also affects the general properties of the flow through the machine. On one hand, it
affects the matching of the flow exiting the impeller and the flow along the volute and, on the other hand, the increment of the impellertongue gap is expected to result in a decrease of the fluid dynamic loads on the machine. A numerical study is presented on the flow
through a conventional vaneless volute centrifugal pump, equipped with four impellers so that the impeller-tongue gap ranged from 8.8%
to 23.2%. Five different flow rates, ranging for 20% to 160% of the nominal flow rate, were simulated for each of the impellers by means
of commercial software that solved the 3D-URANS equations. Sensitivity tests for one of the impellers proved that the predictions were independent of the numerical parameters and, additionally, the predictions were compared to experimental data which allowed for the validation of the numerical model. This paper reports on the variation of the general performance characteristics of the pump operating with
the different impellers tested, resumed in the proposition of pseudo-similarity correlations. Also, an analysis is presented on the effect of
impeller trimming on the local flow changes at the tongue region that are related to the passage of the impeller blades. Finally, the dynamic loads on the machine are estimated as a function of flow rate and impeller-tongue gap.
Key words: centrifugal pump, impeller trimming, numerical simulation, unsteady flow, blade-passing frequency, fluid-dynamic load.
INTRODUCTION
critical values, and so the fluid-dynamic perturbations at fBP can
The operation basis of fluid turbomachinery is inherently un-
represent an important performance limitation. Hence, there is in-
steady because the energy transmission between machine and
terest in being able of predicting the properties of the unsteady flow
fluid is conditioned to the impulse of the blades that rotate with re-
through the centrifugal pumps [8], and also in estimating the un-
spect to the stator. In the case of conventional centrifugal pumps
steady load at the design stage of the machine. This may be
with volute casing operating under normal conditions, a relevant un-
achieved by means of the numerical resolution of the Reynolds aver-
steady phenomenon is the fluid-dynamic rotor-stator interaction
aged Navier-Stokes equations for unsteady flow (URANS), with a
and, in particular, the periodic interaction between the impeller
proper CFD code. Several numerical studies have been reported in
blades and the volute tongue [1,2]. This excitation arises from the
the technical literature on vaneless volute centrifugal pumps with
non-uniform profile of the relative flow exiting the impeller, with jet-
different specific velocities and radial blade-tongue gaps. Usually
wake patterns, which is attributed to the blade thickness, the
these studies emphasized the prediction of the amplitude of the
boundary layer on both sides of the blades and the secondary flows
pressure fluctuations, at first for operation at the nominal flow rate
inside the impeller channels. The non-uniform flow profile is per-
and afterwards for wider ranges of the operating point. The flow
ceived in the volute as unsteady [3], with dominant fluctuations as-
models used range from 2D unsteady flow [9] and 3D quasi-
sociated to the blade-passing frequency fBP and harmonics. This ex-
unsteady flow [10] to fully 3D unsteady flow [11-13], with different
citation is especially intense where the distance between impeller
choices of turbulence models and boundary conditions.
and volute is small, that is, at the tongue region of the volute [4].
Following previous work by the authors [14], this paper pres-
On the other hand, for a given pump the amplitude of the pulsations
ents a numerical study on the pulsating flow at the tongue region
increases fast as the point of operation deviates from the best effi-
for a conventional centrifugal pump with a single vaneless volute,
ciency flow rate, towards both small or high flow rates [5, 6].
equipped with four impellers of different outlet diameter: 0.190,
Very frequently, the radial gap between impeller and tongue is
0.200, 0.210 and 0.215 m and seven blades. These four impellers,
altered in commercial pumps because manufacturers commonly
obtained from progressive trimmings from a primary impeller, per-
use the trimming of the impellers to be mounted in a specific volute
mitted to vary the impeller-tongue gap from 23.2% to 8.8% of the
as a means to augment the range of performance characteristics
impeller outlet radius. The unsteady 3D Reynolds averaged Navier-
while precluding excessive production costs. This brings about the
Stokes equations were solved by means of the commercial code
modification of the flow velocity and pressure distribution along the
Fluent for each of the four impellers. Additionally, experiments
volute, together with a change in efficiency for moderate impeller
were conducted in laboratory for the same pump, equipped with the
cutbacks [6, 7].
0.210 m impeller, to measure the pressure fluctuations along the vo-
The vibration and noise levels of pumps must not exceed certain
lute for different flow rates, in order to contrast the predictions from
Departamento de Energía, Universidad de Oviedo. Campus de Viesques - e-mail: [email protected]
14
TECHNICAL ARTICLE
computations. The numerical results were used to obtain the tem-
steps per blade passage ranging from 4 to 64 (that is, 28 to 448
poral evolution of the flow variables (velocity and pressure) at the
time steps per impeller revolution). With the final time step size
tongue region during one single blade passage, for flow rates of
used during the simulations, which corresponded to 32 time steps
20%, 60%, 100%, 120% and 160% of the nominal flow rate. The
per blade passage (224 time steps per impeller revolution) the vari-
numerical model also permitted to quantify the dynamic radial
ations observed in the global variables with respect to the smallest
forces on the impellers at the blade-passing frequency.
time step size were less than 0.5%, whereas for the pressure fluctuation was less than 1%. Regarding the turbulence model, simula-
NUMERICAL MODEL
tions were conducted by using the Spalart-Allmaras, k-epsilon, k-
For the computations of the flow through the pump, the domain
omega and RSM. The results showed that with the k-epsilon model,
was separated into four modularized zones: inlet duct, impeller, vo-
the one finally used in the simulations,the variations obtained for all
lute, and diffuser plus outlet duct (see Fig.1), each built and
the reference variables with respect to the RSM were less than 1%.
meshed independently so that only the portion corresponding to
For each of the configurations tested first a steady flow calcula-
the impeller module had to be replaced when changing the impeller
tion was carried out for a given relative position of the impeller by
diameter. This prevented any mesh distortion in the rest of the mod-
means of a frozen-rotor interface. After achieving convergence, the
ules that could affect the results of the simulations. As can be seen
resulting velocity and pressure fields were taken as the initial condi-
in Fig. 1, the impeller module extends further than the physical im-
tions for the proper unsteady flow computations. Each blade pas-
peller towards both the pump inlet and the volute for convenience
sage was computed in a time sequence of 32 steps, that is, 224 time
of grid matching between adjacent modules with relative motion.
steps per revolution. At a rotation speed of 169.95 rad·s-1, the cor-
Besides, the impeller module contains the two lateral spaces be-
responding time interval was 1.65·10-4 seconds. At least ten impel-
tween the casing and each side of the impeller, that is, shroud and
ler revolutions were imposed in the simulation process to ensure
hub; the former extends from the volute until the wear ring round
the achievement of a stabilized periodic solution in the numerical
the eye of the impeller and the second one from the volute until the
sense, that is, the flow variables become periodic when considering
driving shaft. Thus, the effect of the flow confined between the cas-
one full revolution, with predominant fluctuations at the blade-
ing and the impeller surfaces could be taken into account during the
passing frequency. Then the evolution of the flow during one single
simulations.
blade passage was recorded, analyzed and post processed to derive
Different unstructured mesh types were created for each zone
both global and local variables.
depending on the geometrical characteristics, with special mesh refinement at strategic locations, such as the leading edge of the
blades and the tongue region. Prismatic cells were used for the inlet
and outlet pipe portions, and tetrahedral cells were used for the rest
of the domain, including the impeller and volute modules, as can be
seen in Fig.1. Turbulence was simulated by means of a standard kepsilon model, and standard wall functions were used to calculate
boundary layer variables. The time dependent term scheme was
second order implicit. The pressure-velocity coupling was established by means of the SIMPLEC algorithm. Second order upwind
discretizations were used for the convection terms, and central difference schemes for the diffusion terms. As boundary conditions, a
constant total pressure was considered at the inlet, and a uniform
static pressure at the outlet, dependent on the flow rate.
The latter was introduced by means of an added loss proportional to the exit dynamic pressure, which simulates the effect of a
Fig.1. Numerical model of the pump equipped with one of the impellers.
regulation valve, and can be thus expressed as Δp=0.5kLρv2.
Mesh independence tests were carried out for the 0.210 m impeller and the highest flow rate (about 160% of nominal flow rate),
by using mesh sizes ranging approximately between 4·105 to 2·106
cells. These results are presented in Fig.2. With the final mesh used
in the bulk of the simulations, which was around 765,000 cells, the
variation observed in flow rate with respect to the 2·106 cell mesh
was less than 1%, and less than 1.5% for the head. The variation
was even lesser for the amplitude of pressure fluctuations at a
given reference position (j=25 deg measured from the volute
Fig.2. Numerical sensitivity of the model with respect to mesh size.
tongue at the volute front side): less than 0.5%. Additionally, independence tests with respect to time step size and turbulence model
were also carried out for the same impeller and flow rate.
For the first case, there were chosen different number of time
EXPERIMENTAL VALIDATION
To validate the results obtained with the numerical model, the
magnitude of some test variables numerically calculated was com-
15
ARTIGOS TÉCNICOS
pared with the magnitude of the same variables, measured at labo-
d(m)
d*(-)
A(m2)
A*(-)
d*A*(-)
ratory on the pump equipped with the 0.210m impeller. In Fig.3 the
0,190
0,905
0,009440
0,988
0,894
non-dimensional flow-head characteristic is presented for the four
0,200
0,952
0,009482
0,992
0,945
impellers (icons), and also the experimental characteristic for the
0,210
1,000
0,009558
1,000
1,000
0.210m impeller is shown. In this figure, the impeller diameter was
0,215
1,024
0,009683
1,013
1,037
normalized using the relationship d*=d/0.210, where d is the im-
ter are mounted on the same volute. Table 1 shows the magnitude
peller outlet diameter. Measurement uncertainty was estimated to
of the impeller outlet section A as a function of the trimmed diame-
be less than ±0.8% for the flow rate and ±1% for the pump head.
ter d, as well as the product d*·A*. It can be appreciated that the
As can be seen in Fig.3 the comparison of the numerical results
section A increases slightly as d increases. The relationship be-
for the four impellers shows that, for a fixed loss coefficient kL, the
tween the flow coefficient and the diameter can be approximated
icons almost overlap. This is due on the one hand to the type of flow
as follows:
regulation imposed in the numerical simulations and, on the other
hand, to the parameters used for the non-dimensional representa-
F=
Q/A
Q
1
Q
1
=
×
=
×
wd/2 pn / 60 dA p n / 60 d N AN ( d*)a
In this expression the subscript N refers to the nominal impeller
tion of the flow-head characteristics of Fig. 3.
(d=0.210 m, d*=1), and the exponent α is slightly different from
unity. The relationship between head and flow rate for two pseudosimilar operating points I and II can hence be expressed as follows:
H I æ QI ö
÷
=ç
H II çè QII ÷ø
2 /a
which is equivalent to HaQ2 for a=1. For the present case, fitting a
potential function between the fifth and the first columns of Table 1
gives an exponent a of 1.19. As exponent a>1 (and thus 2/a<1)
the new operating point obtained for example when diameter d is
increased corresponds with a slightly lower magnitude of the flow
rate than that of its pseudo-similar operating point, and hence the
Fig.3. Non-dimensional flow-head characteristic of the centrifugal pump
equipped with the four different impellers. The experimental results for
the 0.210 m (d*=1) impeller are also shown.
flow coefficient F diminishes as can be observed in Fig.3. The more
noticeable the effect the higher the initial flow coefficient.
On the other hand, if a low flow coefficient is considered and the
It is usual to design the impellers of centrifugal pumps with
impeller diameter d increases, the flow rate also increases and
some relative slope of the impeller covers to reduce the impeller
tends towards the design flow rate of the volute. This effect causes
exit width as radial coordinate increases. This maintains the mag-
a diminuition of the hydraulic losses within the volute, better effi-
nitude of the meridian velocity almost constant along the last por-
ciencies and, in conclusion, a small rise of the head coefficient. The
tion of the impeller channels, and prevents an excessive rise of the
same type of reasoning can be applied to other regions of the ma-
boundary layer within the channels. If the reduction in the exit
chine that are not affected althought the magnitude of the impeller
width makes up for the increase in diameter and the effective sec-
outlet diameter was modified, for example the inlet region of the im-
tion at impeller outlet remains constant (neglecting the effect of
peller. This effect can also be appreciated in Fig.3, especially for the
blade thickness), it follows that the flow coefficient and the impel-
smallest flow coefficients.
ler diameter relate as faQ/D for a constant driving speed of the im-
The comparison of the numerical and the experimental data of
peller. On the other hand, the relationship between the head coeffi-
Fig. 3 for the 0.210 m impeller give good qualitative and quantita-
cient and the impeller diameter can be expressed as yaH/D .
tive agreement. The difference between the head predicted and
Hence, between two “pseudo-similar” operating points of two
measured for this impeller remains below 6% for all flow rates but
trimmed impellers, in the sense that they maintain the same value
the highest one; for the latter, for which the head curve drops fast
of the flow and head coefficients, the relationship between head
when further increasing the flow rate, the difference between the
and flow rate is quadratic and can be expressed as HaQ . In fact,
flow rate predicted and measured (for the same measured head)
this is the relationship imposed by the boundary conditions during
was about 11%. Part of these differences can be attributed to the
the numerical simulations (an added loss proportional to the exit
leakage flow between volute and impeller inlet, which was not con-
2
2
2
dynamic pressure and hence to Q ).
sidered in the numerical model.
2
The expression HaQ can thus be considered a reasonable
Additionally, dynamic pressure measurements were carried out
“pseudo-similarity” law to relate the flow-head characteristics of
on the pump instrumented with piezoelectric pressure transducers
trimmed impellers working with the same loss coefficient kL. The
mounted on the front side of the volute at 36 measurement posi-
small differences that can be observed in Fig. 3 between the icons
tions, that were located every 10 deg around the impeller at a ra-
for a fixed value of kL are attributed to the fact that the outlet sec-
dial distance of 2.5 mm from the impeller outlet. Pressure signals
tion of the impeller does not remain strictly constant when the im-
from the transducers were amplified, digitized and FFT processed
peller is trimmed, and also it must be taken into account that there
to obtain the spectral distributions of the pressure and, especially,
is not a real geometric similarity when impellers of different diame-
the pressure pulsation at fBP. The measurement uncertainty esti-
16
TECHNICAL ARTICLE
mated for these measurements was ±1.5%. Similarly, the pressure values computed at 36 positions equivalent to the locations
used in the experiments were recorded during one blade passage
(32 time instants) and FFT processed to obtain pressure amplitudes and phases at fBP.
Comparison between the numerical and the experimental pressure fluctuation data gave a satisfactory concordance, even quantitatively, which is in agreement with previous results by the authors [11]. The most remarkable difference with respect to measurements corresponded to the two low flow rates in the neartongue region of the volute (0<j<30 deg), that is, the zone with
maximum pressure fluctuations: predictions underestimated
these maximum amplitudes in about 40%. At least in part, this dif-
Fig.4. Time evolution of the tangential and radial velocities and of the
static pressure during a blade-passage period for three flow rates.
Point “a”: solid icons. Point “b”: hollow icons.
ference could be attributed to the flow separation that is expected
sure, when the blade lines up with the corresponding reference po-
from the tip of the tongue towards the volute side for such low flow
sition, due to the secondary flow from the pressure to the suction
rates, because it represents a notorious difficulty for a precise nu-
side of the blade. The radial velocity gets a maximum somewhat be-
merical simulation of the flow in that region. Further details about
fore the pressure side of the blades arrives at each of the reference
these experimental measurements can be found in [15, 16].
positions, and gets a minimum when the blades progress after
those positions, showing the jet-wake character of the flow.
UNSTEADY FLOW AT THE TONGUE REGION
The net flow at the tongue region fluctuates according to the
Prior to study the effect of the impeller trimming on the local
time evolution indicated for the pressure and velocity components.
flow pulsations at the tongue region, the time evolution of the ve-
Hence, at t*=0.8 when the static pressure at the inner side of the
locity components and the static pressure was recorded and ana-
tongue (point “a”) is maximum, in the gap region (point “b”) the ra-
lyzed for the 0.210 m impeller. The objective was relating the pas-
dial velocity is maximum and the tangential velocity is relatively
sage of the impeller blades with the tangential and radial velocity
small. This indicates a minimum value of the leakage flow through
pulsations at some reference positions, and with the pressure pul-
the gap, because a big portion of fluid is pushed by the blade to-
sations at the tongue region.
wards the discharge throat. Additionally, the portion of fluid with
Fig. 4 shows the time evolution of the tangential and radial ve-
high radial velocity impinges on the volute tongue and this interac-
locities (first and second row respectively) and of the static pres-
tion causes a rise of the static pressure observed at point “a”. On
sure (third row) for three flow rates (20%, 100% and 160% of the
the contrary, for t*=0.1 the radial velocity in the gap region is rela-
nominal flow rate, one in each column). The velocity components
tively low as well as the static pressure at “a”, whereas the tangen-
are presented normalized with respect to the tangential velocity at
tial velocity of the flow through the gap is relatively high thus indi-
impeller periphery; the time is presented normalized by the blade-
cating an increase of the leakage through the impeller-tongue gap.
passing time. In each diagram the solid icons correspond to posi-
The results obtained for the 20% flow rate show that the aver-
tion “a”, located ϕ=10 deg upstream from the volute tongue and
age value of the radial velocity is about zero at j=10 deg and even
the hollow icons correspond to position “b”, located in front of the
negative at j=0 deg, due to the strong leakage of flow from the
tongue-tip (see simplified scheme of Fig. 4). Both positions “a” and
wide side of the volute through the impeller-tongue gap. This
“b” lie in the radial coordinate r*=1.04, that is, a 4% out from the
strong leakage was found to be induced by a large counter rotating
impeller periphery. The solid lines, labeled “a” and “b”, represent
vortex inside the impeller channels and close to the pressure side
the time interval when the blade trailing edge is passing in front of
of the blades. Considering point “a”, when the blade trailing edge
the considered position.
passes in front of it at t*=0.1, both the tangential and radial veloc-
As can be seen in Fig.4, for the nominal flow rate the only rele-
ities reduce to a relative minimum. A little time later both velocity
vant fluctuation observed in the tangential velocity is a small veloc-
components increase and, especially, the radial component, ob-
ity drop when the blade approaches and passes by each of the ref-
taining maximum values at about t*=0.3, because point “a” re-
erence positions, which can be attributed to the relative flow be-
ceives the flow exiting the impeller close to the blade suction side
tween the pressure and the suction side of the blades. The same
(the rest of the impeller channel is occupied by the vortex), with a
counts for the radial velocity fluctuations: the radial velocity drops
relatively large discharge angle with respect to the tangential di-
as the blade passes by each of the reference positions due to the
rection. Afterwards, the progressive motion of the impeller brings
wake blockage (that is, when the tangential velocity drops).
about the passing of the vortex core in front of point “a” at t*=0.6,
Afterwards the radial velocity remains with little change during a
so the discharge angle of the flow seen from “a” reduces down to
significant portion of the blade passage period. The predictions of
negative values and the tangential and the radial velocities at “a”
the velocity fluctuations manifest the known “jet-wake” pattern
become minimum. Finally, as the vortex moves away both tangen-
and are correlated with the fluctuations in the pressure field, al-
tial and radial velocities increase again.
though these pressure fluctuations are very small.
The velocity fluctuations bring about pulsations in the leakage
For the 160% flow rate (third column of Fig. 4) it is shown that
flow between impeller and tongue. Approximately at t*=0.2, when
the tangential velocity gets a minimum simultaneously with pres-
the vortex moves towards position “b” and the pressure is maxi-
17
ARTIGOS TÉCNICOS
mum at the inner side of the tongue, the leakage flow is partially
cated, which induced strong variations in the leakage through the
blocked (low values of the tangential velocity at point “b”) by the
impeller-tongue gap and hence in the velocity components. The
flow with high radial velocity that exits the impeller close to the
maximum pulsation of the radial velocity for the 20% flow rate was
blade suction side. On the contrary, at t*=0.5-0.6, when the radial
obtained at j=-10 deg with the 8.8% radial gap. In this case, re-
velocity and pressure are minimum, fluid from the tongue region
ducing the gap ratio from 23.2% to 8.8% leads to an increment of
re-enters the impeller channel close to the blade pressure side (low
the radial velocity pulsation of about a 490%. Finally, and regard-
negative values of the radial velocity at point “b”), producing an in-
ing the pressure fluctuations, the maximum pulsation magnitude is
crement in the tangential velocity through the gap and thus in the
obtained, as in the case of the tangential velocity, for the highest
leakage flow.
flow rate. This pulsation reaches maximum values at j=10 deg,
that is, at the inner side of the tongue. If the gap ratio is reduced
from 23.2% to 8.8% the increment of the pressure pulsation is
about a 520%.
UNSTEADY LOAD AT THE BLADE PASSING FREQUENCY
The numerical model could be used to compute the total radial
forces and torque by means of a full integration of the instantaneous pressure and shear stress distribution, determined numerically on the impeller surfaces: blades, shroud and hub. The time
signals of the force components and of the torque in the x and y directions were FFT processed to give the amplitude corresponding
to the blade passing frequency and its harmonics. The results of
this process are presented in Fig. 6; Fig. 6(a) shows the maximum
Fig. 5. Peak-to-peak fluctuations of velocity components and pressure as
a function of impeller-tongue gap, at the three reference positions of
Fig.4. Solid circles: 20% flow rate. Solid squares: 60% flow rate.
Stars: nominal flow rate.Hollow circles: 120% flow rate.
Hollow squares: 160% flow rate.
amplitude of the total unsteady radial force at the blade passing frequency, for each impeller and flow rate tested, as a function of the
impeller-tongue gap G and, similarly, Fig. 6(b) presents the maximum torque amplitude at fBP.
In Fig. 5 the magnitude of the fluctuations (peak-to-peak) of velocity components and pressure, as a function of the impellertongue radial gap G, is presented for each of the flow rates tested.
The first and second columns correspond to j=10 and j=0 deg
(points “a” and “b” of Fig. 4). The third column presents the results
obtained at point “c”, which was located near the tongue-tip but at
the wide side of the volute.
From Fig. 5 it can be seen that, for any reference variable considered, the pulsation magnitude augments as the impeller-tongue
Fig. 6. Maximum amplitude of the total unsteady radial force (a) and of
the torque (b) obtained at the blade passing frequency, for each impeller
and flow rate tested.
gap G diminishes. The peak-to-peak fluctuations are especially
As can be seen in Fig. 6(a), for a given impeller the maximum
high for the two smaller radial gaps considered in this study, that is,
force value is lowest at nominal flow rate and increases at off-
11.4% and 8.8% of the impeller radius, whereas the pulsation mag-
design conditions. Quantitatively, this trend depends on the gap
nitude is relatively low and quite similar for the other two impellers
value: in the case of the two smallest impellers, the magnitude of
(radial gaps of 17.0% and 23.2%). Regarding the tangential veloc-
the maximum force is similar for both low and high flow rates,
ity, it can be seen that the maximum pulsations are produced with
whereas the two biggest impellers present force magnitudes that
the pump operating with the two higher flow rates (120% and
are particularly high for the low flow rates. On the other hand, for
160% of nominal flow rate), which is more noticeable at j=0 deg.
any given flow coefficient the maximum value of the normalized un-
The pulsations for low and medium flow rates (20%, 60% and
steady radial force increases when diminishing the impeller-
100% of nominal flow rate) are quite similar for any radial gap con-
tongue gap, with more accused variations for the smallest gaps. A
sidered, though slightly higher for the 20% flow rate; this is partic-
total variation of impeller diameter between the smallest and big-
ularly evident at G=8.8% and j=10 deg. The magnitude of the pul-
gest values used in this study (from 23.2% to 8.8%), results in mul-
sation of tangential velocity, when reducing the gap ratio from
tiplying the maximum unsteady force by a factor of 3.8 for small
23.2% to 8.8% and if high flow rates are considered, can augment
flow rates and about 2.8 for the big flow rates. This trend matches
up to 345%.
well with a relationship of proportionality between the maximum
-n
The pulsation of the radial velocity shows similar tendencies to
force amplitude and G (with n>0) as proposed in [3] to correlate
that of the tangential velocity, but now its magnitude is especially
pressure pulsations. The present predictions of the maximum un-
high for low flow rates and, particularly, for the 20% flow rate. This
steady force indicate values of 1.4 for the small flow rates and 1.1
fact could be attributed to the vortex within the impeller channels
for the big flow rates, with regression coefficients R well above
that was found to develop at the lowest flow rate, as previously indi-
0.99 for all the flow rates tested.
18
2
TECHNICAL ARTICLE
Regarding the torque amplitude (Fig. 6(b)), it can be observed
tive increment of the pulsation of about 490% when reducing the
that the general trend of the curves resembles that of Fig. 6(a),
gap ratio from 23.2% to 8.8%. The pressure pulsation at the
with minimum values of the fluctuating torque for flow rates close
tongue region was especially strong for the highest flow rate, and
to the nominal one. Varying the gap ratio from 17.0% to 8.8%
could reach a relative increment of 520% when varying the impel-
makes the fluctuating torque amplitude multiply by factors of
ler diameter from 0.190 m to 0.215 m.
about 3.2 for the small flow rates and 2.4 for the big ones. A fit of
-n
The numerical model could also be used to estimate the blade-
the torque data with a potential function of the type G gives expo-
passing component of the unsteady load on the impeller due to
nents of n similar to the ones obtained by fitting the force data, but
blade-tongue interaction. A total variation of impeller diameter be-
2
in this case the regression coefficients R are poor (usually below
tween the smallest and biggest values used in this study, resulted
0.9). The torque fluctuation amplitude showed in Fig. 6(b) is par-
in multiplying the maximum unsteady force by a factor of 3.8 for
ticularly high for the small flow rates, for which the steady driving
small flow rates and about 2.8 for the big flow rates, which
torque is low. This results in high values for the relative torque fluc-
matched well with a relationship of proportionality between the
tuations with respect to the mean torque, especially for the small-
maximum force amplitude and G with n=1.1-1.4. Regarding the
est tongue gaps. For the present case and a flow rate of about 60%
torque fluctuations, it was found that varying the gap ratio from
of nominal flow rate, the relative torque amplitude (zero-to-peak)
17.0% to 8.8% made the fluctuating torque amplitude multiply by
is 3.1% and 4.4% of the steady torque predicted for the impellers
factors of about 3.2 for the small flow rates and 2.4 for the big
with gap ratios of 17.0% and 8.8% respectively. The same relative
ones. The torque pulsations could reach a 7.6% of the mean torque
torques reach values of 5.7% and 7.6% when considering a flow
when considering a flow rate of about 20% of nominal flow rate for
rate of about 20% of nominal flow rate.
the 0.215 m impeller.
-n
CONCLUSIONS
ACKNOWLEDGEMENTS
The effect of the blade passage in front of the volute tongue was
The authors gratefully acknowledge the financial support of the
investigated for a centrifugal pump that could be equipped with im-
Ministerio de Educación y Ciencia (Spain) under Project MEC06-
pellers of different diameter. The study was carried out by means of
DPI15034, and of the Fundación para el Fomento en Asturias de la
the numerical simulation of the unsteady flow and it focused on the
Investigación Científica Aplicada y la Tecnología (FICYT).
local flow variations at the tongue region, as a function of flow rate
and impeller-tongue gap.
It was found that, for the nominal and high flow rates, at the
side of the tongue closest to the impeller exit pressure maxima coin-
BIBLIOGRAPHICAL REFERENCES
[1] BRENNEN CE. 1994. Hydrodynamics of Pumps. Oxford
University Press and CETI Inc. (New York).
cided with high values of the radial velocity and low values of the
[2] JAPIKSE D, MARSCHER WD and FURST RB. 1997.
tangential velocity, indicating a minimum leakage through the im-
Centrifugal Pump Design and Performance. Concepts ETI Inc.
peller-tongue gap and an impinging of the fluid exiting the impeller
(Wilder, VT).
on the inner side of the volute tongue. On the other hand, pressure
minima coincided with low values of the radial velocity and high val-
[3] GUELICH JF and BOLLETER U. 1992. Pressure Pulsations in
Centrifugal Pumps. ASME J. Vib. Acoust., 114, pp. 272-279.
ues of the tangential velocity, thus indicating a maximum impeller-
[4] CHU S, DONG R and KATZ J. 1995. Relationship Between
tongue leakage. The predictions of velocity fluctuations also
Unsteady Flow, Pressure Fluctuations and Noise in a Centrifugal
showed the known “jet-wake” pattern of the flow exiting the impel-
Pump—Part B: Effects of Blade-Tongue Interactions. ASME J. Fluids
ler. For the 20% flow rate pressure maxima was found to be caused
Eng., 117, pp. 30-35.
by the blockage of the leakage flow by the flow which left the impel-
[5] PARRONDO JL, GONZÁLEZ J and FERNÁNDEZ J. 2002. The
ler close to the blade suction side with a high value of the radial ve-
Effect of the Operating Point on the Pressure Fluctuations at the
locity. The presence of a large counter rotating vortex inside the im-
Blade Passage Frequency in the Volute of a Centrifugal Pump.
peller channels close to the blade pressure side explained this phe-
ASME J. Fluids Eng., 124, pp. 784-790.
nomenon. On the other hand, pressure minima coincided with low
[6] NEUMANN B. 1991. The Interaction Between Geometry and
values of the radial velocity, even negative, and relatively high val-
Performance of a Centrifugal Pump. Mechanical Engineering
ues of the tangential velocity, which were induced by the re-
Publishers (London).
entrance of fluid from the tongue region towards the impeller channel forced by the vortex.
The peak-to-peak pulsations of velocity components and pressure were found to be especially high for the two smaller radial
gaps considered in this study (11.4% and 8.8% of the impeller out-
[7] KITTREDGE C. P. 1985. Centrifugal Pumps: General
Performance Characteristics. In Karassik I. G., Krutzsch W. C.,
Fraser W. H. and Messina J. P, Pump handbook. McGraw Hill, second edition (New York).
[8]
GOPALAKRISHNAN
Past,
S.
Present,
1999.
and
Pump
let radius), and for the 120% and 160% flow rates if the tangential
Development:
velocity was considered. The pulsations could augment up to 345%
Perspective. ASME J. Fluids Eng., 121, pp. 237-247.
Research
Future—An
and
American
when reducing the radial gap ratio from the maximum to the mini-
[9] CROBA D and KUENY JL. 1996. Numerical calculation of 2D,
mum value. For the 20% flow rate the pulsation of the radial veloc-
unsteady flow in centrifugal pumps: impeller and volute interac-
ity was especially high due to the strong variations in leakage in-
tion. Int. J. Num. Meth. in Fluids, 22, pp. 467-481.
duced by the vortex previously indicated, and could lead to a rela-
[10] ASUAJE M, BAKIR F, TREMANTE A, NOGUERA R and REY R.
19
ARTIGOS TÉCNICOS
Strength Analysis of the Axial Flow Blades Based on CFD
1
Zheng Xiaobo
2
Luo Xingqi
3
Guo Pengcheng
ABSTRACT
Based on the Reynolds-averaged N-S equations and the standard k-ε model, the numerical simulation of three-dimensional flow
through axial flow runner was conducted by using the finite volume method with the non-structural grid systems in the paper. And the water pressure distribution on the blade surface was obtained, thus the actual stress distribution on the blade surface. With finite-element
method, strength analysis of the axial flow blades was conducted by loading the water pressure on the surface of the blade model.
According to the result, the maximal stress and distortion occur on the point with the maximal water head and the rated power.
Key words: CFD analysis, FEM, Axial flow runner, Strength
INTRODUCTION
part of inlet, rotating part of runner and static part of outlet (Fig.1).
When operation, axial flow blades with cantilever structure
Non-structural grids were calculated for every part (Fig.2). Sliding
bear the water pressure, centrifugal force, fabrication stress and so
grid method was used to treat the rotor-stator interaction between
on. Besides start-up process and shutdown process, the runner
static part and rotating part.
needs to operate under off-design condition in most of the time,
thus to result a bad working environment. Therefore, the blades
FINITE ELEMENT EQUATION FOR STRENGTH ANALYSIS
must often bear the various centrifugal forces exciting force of
In view of dynamic balance conditions and boundary condi-
steady and unsteady caused by all kind of factors. The vibration of
tions, the dynamic equilibrium equation for structure was shown as
the blades due to exciting force of the factors may lead to fatigue
follows with finite element forms (Ref.2):
failure of the structure, and even blade crack. In engineering practice, the stiffness and strength analysis of the blades become more
and more important to avoid and deal with the blade crack.
In view of the short-cut method used generally in present in-
In which, [M]is mass matrix, [C]is damping matrix, [K]is stiffness
matrix, {Qc}is centrifugal force load vector of the structure under ini-
tensity analysis, this paper proposed a method which load contin-
tial state, {P}is equivalent node load vector on structure surface,
ual hydrodynamic pressure on the FEM model to be studied as dis-
{Fd}is equivalent node load vector caused by initial stress, {R}is
crete point on different time and carry on the dynamic stress analy-
node concentrated force vector.
sis of the blade. This method can obtain the change of water pres-
A whole blade with trunnion was selected as the model for
sure on blade surface and results of stress analysis that reflect the
structure strength analysis. The Young modulus, Poisson ratio and
actual operational aspect. The method is quite practical worth in
density are 300 GPa, 0.27 and 8050kg/m3 respectively. Structural
solving the problem of blade crack in hydropower station.
grid with 8-nodes hexahedral element was calculated for strength
analysis. Blade flange is treated as fixed end.
MATHEMATICAL MODEL FOR FLOW ANALYSIS
Based on the Reynolds-averaged N-S equations and the stan-
RESULTS AND ANALYSIS
dard k-ε model as follows (Ref.1), the numerical simulation of
The work was conducted with the axial flow runner of a certain
three-dimensional flow through axial flow runner was conducted
power station. Three running conditions were calculated, which are
by using the finite volume method with the non-structural grid sys-
rated condition, maximum water head condition with rated power
tems in the paper.
and running away condition.
The continuity and momentum equations for incompressible
viscous flow are as follows
According to the results(Table.1,Fig.5 and Fig.6)， maximum
stress of 201Mpa appeared on the outlet direction endpoint of intersection line between the blade pressure surface and the blade
flange under maximum water head condition with rated power.
Under rated condition, the maximum stress appeared on the outlet
meffdenotes effective viscidity coefficient, meff+mt.mt denotes turbulent viscidity coefficient.
direction endpoint of intersection line between the blade pressure
surface and the blade flange. Under running away condition, the
maximum stress appeared on the outlet direction endpoint of intersection line between the blade suction surface and the blade
According to the flow symmetry, one blade cycle was treated as
flange.
the physical model. The flow field was separated three parts: static
1 Associate Professor, 2 Principal Professor,3 Associate Professor of Institute of Water Resources and Hydro-Electric Engineering - Xi'an University of Technology.
e-mail: [email protected]; [email protected]; [email protected]
20
TECHNICAL ARTICLE
Application of Auto CAD in the Design of Hydrulic Turbine”.
Table.1 Results of blade strength analysis
JOURNAL OF SHAANXI WATER POWER. Vol.11， No.4, pp. 53-56.
(in Chinese).
[4] Saeed Moaveni. Finite Element Analysis: Theory and
Application with ANSYS, 2nd Edition. Published by Prentice-Hall.
January 16, 2003
CONCLUSIONS
3D solid modeling of the blade was done by used the soft named MDT in this paper. And the numerical simulation of threedimensional flow through axial flow runner under three conditions
was conducted by using the finite volume method with the nonstructural grid systems based on the Reynolds-averaged N-S equations and the standard k-ε model. Water pressure distribution on
the blade surface was obtained. Continual water pressure were
loaded on the FEM model to be studied as discrete point and
strength analysis of the axial flow blades was carried on.
The results indicates that the stress peak value and displacement peak value of blade under maximum water head condition
with rated power were maximal in three conditions. The stress
Fig.1 Geometrical model for flow analysis
Fig.2 Non-structural grid for flow analysis
peak value and displacement peak value appeared on two points.
They are the outlet direction endpoint of intersection line between
the blade pressure surface and the blade flange and the outlet direction endpoint of intersection line between the blade suction surface and the blade flange.In practical engineering, more attention
should be given to the zone of stress concentration And the results
Fig.3 Geometrical model for strength analysis
Fig.4 Structural grid for strength analysis
shows that the method combination CFD and stress analysis proposed in this paper can reflect the actual forced state on blade surface under different condition. The method is quite practical worth
in solving the problem of blade crack in hydropower station.
ACKNOWLEDGEMENTS
This research was supported by the National Nature Science
Foundation of China, Grant No. 90410019.
(a) Pressure surface
(b) suction surface
Fig.5 Pressure distribution on blade surface under rated condition
REFERENCES
[1] LIAO,Weili and LI,Jianzhong. (2002).”Numerical Simulation
and Study of Internal Flows Through the Spiral Case”. Journal of
Xi'an University of Technology. Vol.18，No.1. (in Chinese).
[2] Qiu Kai. “3D Finite Element Analysis of Strength and
Vibration in Centrifugal Compressor Impeller”. Doctoral dissertation from Xi'an Jiao Tong University. 1999.3. (in Chinese).
[3] Liao Weili, Zhang Haiping and Liang Wuke (1995).”
(a) Rated condition
(c)Running away condition
(b) Maximum water head condition
Fig.6 Stress distribution on blade surface under different condition
ACESSEM TODOS OS NOSSOS ARTIGOS EM:
www.cerpch.org.br
21
ARTIGOS TÉCNICOS
SIMULAÇÃO DO ESCOAMENTO EM UM TUBO D E SUCÇÃO DE UMA MÁQUINA
HIDRÁULICA MOTORA COM CONTROLE DE VAZÃO FEITO POR UM
OBTURADOR INSERIDO NA SUA SEÇÃO DE SAÍDA.
1
Patrícia Santos Tertuliano
2
Geraldo Lúcio Tiago Filho
3
Harley Alencar de Souza
RESUMO
Este artigo contempla o estudo de modelagem através da técnica de dinâmica de fluido computacional – CFD do escoamento em um tubo de sucção, cujo controle de vazão é feito por um obturador inserido na sua seção de saída. Trata-se de um estudo inserido no desenvolvimento de um sistema de controle de velocidade denominado SISCOV®, desenvolvido pelo Centro de Referência em Pequenas Centrais
Hidrelétricas (CERPCH), com o objetivo de atender a necessidade de controlar a velocidade de rotação de máquinas hidráulicas motoras
desprovidas de sistemas distribuidor, como é o caso de bombas centrifugas operando como turbina – BFT, ou de turbinas de concepção
mais simples.
Palavras-chave: Dinâmica do Fluido Computacional, Sistemas de Controle, Bomba Funcionando como Turbina - BFT
ABSTRACT
This article addresses the modeling study using the technique of computational fluid dynamics - CFD flow in a suction tube, whose control flow is done by a plug inserted into its output section. This is a study included in the development of a control system flow called
SISCOV ®, developed by the Reference Center on Small Hydropower (CERPCH), with the objective to control the rotational speed of
hydraulic machines devoid of system distributor , as is the case of centrifugal pumps operating as turbines - BFT, or turbine design simpler.
Key words: Velocity Control System; Computational Fluid Dynamic - CFD, Pumps operating as Turbine - BFT
1.INTRODUÇÃO
Como caso deste trabalho a intenção foi definir o campo opera-
O objetivo desse trabalho é apresentar os resultados da análise
cional do obturador, suprimiu-se o controlador CLP e o sistema foi
computacional do escoamento no tubo de sucção de uma bomba
operado manualmente, por meio de um volante acoplado á haste
funcionando como turbina, feita a partir da dinâmica de fluido com-
do obturador. A figura 1 mostra um esquema básico do sistema de
putacional (CFD) de um sistema de controle de vazão atuando na
controle de vazão.
sua seção de saída. O sistema de controle foi desenvolvido para
ser aplicado em máquinas hidráulicas motoras desprovidas de sistema de controle, como é o caso de bombas funcionando como turbina – BFT e outras turbinas hidráulicas de pequeno porte desprovidas de distribuidor.
O modelo foi simulado a partir de dados de ensaios experimentais realizados no Laboratório Hidromecânico Didático Científico de
Pequenas Centrais Hidrelétricas –LHDC- da UNIFEI, e permitiu verificar a capacidade e a viabilidade deste sistema vir a ser utilizado
par controle de velocidade do grupo hidrogerador, Santos(2005).
Figura 1 - Sistema de controle de vazão
1.2- Princípios de Funcionamento do Sistema de
1.1.Definição
do
Equipamento
Utilizado
para
a
Simulação
Controle de Vazão
De acordo com o esquema apresentado na Figura 2, O sistema
Conforme mostrado na Figura 1, o sistema de controle de vazão
s de controle, aqui denominado de SISCOV®, é composto por um
SISCOV® é composto por um obturado cônico, inserido na seção
CLP associado à variação da rotação e/ou freqüência do gerador
de saída do tubo de sucção e operado por uma haste vertical ligado
que comando um servomecanismo que atuará em um obturador in-
por um servomecanismo. O obturador, comandado pelo servome-
serido na seção de saída do tubo d e sucção. Tipicamente, ao ocor-
canismos, se desloca verticalmente obstruindo ou desobstruindo a
rer uma variação na carga , ocorre uma variação na rotação no gru-
passagem da água em função da carga demandada à turbina, de
po gerador. Essa variação é captada pelo CLP que envia um sinal ao
forma a manter a rotação do grupo gerador constante. O servo-
servomotor acoplado à haste do obturador que movimenta o obtu-
mecanismo é controlado por um CLP, que tem a função de controlar
rador, abrindo-o ou fechando-o, conforme for o caso, mantendo a
a rotação da máquina constante.
velocidade de rotação do eixo da turbina constante. Figura 2
1 e 2 - Programa de Mestrado Engenharia da Energia - Universidade Federal de Itajubá -1. Eng.Msc. 2. Prof. Dr.
3 - Alstom Brasil - 3. Eng. Dr.
22
TECHNICAL ARTICLE
A partir destes resultados, obtidos experimentalmente, desenvolveu-se a modelagem numérica do sistema de controle
SISCOV® através do processo computacional fluido-dinâmico CFD.
2 MÉTODO UTILIZADO NA SIMULAÇÃO EM CFD
Existem várias técnicas numéricas de solução e suas diferenças
estão associadas à forma com que as variáveis incógnitas são aproximadas e ao procedimento de discretização, o mais adequado ao
estudo proposto é o método de volumes finitos, devido a sua capacidade de estudar geometrias mais complexas.
2.1.Propriedades Físicas
A tabela 3.1 mostra as propriedades físicas necessárias para deFigura 2- Funcionamento do Sistema
finição da condição de contorno na realização do cálculo numérico.
Tabela 3.1 – Lista de variáveis para o cálculo
1.3 - Zonas de Atuação do obturador cônico
De maneira a se determinar o campo operativo do obturador, realizou-se ensaios experimentais em um obturador instalado em tubo de sucção de uma bomba funcionando como turbina- BFT, instalada na plataforma de ensaios do Laboratório Didático Cientifico para Pequenas Centrais Hidrelétricas - LHDC, da Universidade
Federal de Itajubá-UNIFEI, conforme esquematizado na Figura 2.
Foram feitos testes em dois obturadores com diferentes ângulos de conicidade:um com 60º e 30º . Os ensaios tinham como objetivo determinar a curva característica dos obturadores de maneira
2.2.Processamento
a se detectar suas zonas operativas, definidas como sendo: X0 e
2.2.1.Geração da Malha
X1: Zona de controle e X1 e X2 Zona sem atuação de Controle.
A Figura 3 refere-se ao modelo geométrico do escoamento no
Como o ângulo de conicidade que resultou em melhores resultados
tubo de sucção com o obturador cônico inserido em sua seção de sa-
foi o de 30º, Santos (2009) este trabalho se limitará a apresentar
ída, construído a partir do ICEM CFD.
este obturador.
Figura 3 – Campo de operação do obturador:
(a) Zonas de controle e sem controle;
(b) Posição do Cone versus Vazão para o ângulo de conicidade α=30º
Figura 3 – Modelo Geométrico do tubo de Sucção e do
Sistema de Controle de vazão
O tanque onde está inserida seção de saída do tubo de sucção
A Figura 3.b mostra a curva de variação da vazão em relação a
tem o formato retangular, para facilitar a definição das condições
abertura do obturador, com ângulo de conicidade de 30º mostran-
de contorno e facilitar os cálculos, na construção da geometria con-
do a zona de atuação do SISCOV. O gráfico representa a vazão na
siderou-se um tanque circular. Porém, na prática pode-se conside-
saída do tubo de sucção em função da a abertura do obturador. O in-
rar para este estudo irrelevante o formato do tanque, pois o mes-
tervalo indicado pelos pontos (X0=0,120m) e (X1=0,229m) repre-
mo não influenciará nos resultados devido a sua dimensão ser mui-
senta a zona sem atuação de controle, enquanto o intervalo indica-
to maior que a dimensão da saída do tubo de sucção.
do por (X1=0,229m) e (X2=280m) mostra a zona com atuação de
controle.
Após a construção da geometria verifica-se se a mesma está
compatível com o modelo. Para tanto utiliza-se das ferramentas do
A área entre os pontos A e B há uma zona sem controle, onde o
próprio ICEM CFD. Desta foram elimina-se todos os erros que pos-
obturador não influencia no controle da vazão, sendo o início da zo-
sam ter ocorrido na geometria durante a construção da mesma. Se
na de controle dado a partir do ponto B até o ponto C, sendo que na
não forem corrigidos antes da geração da malha, estes erros po-
medida em que esse obturador se movimenta de B para C ocorre
dem resultar em erros de formação da mesma e possivelmente nos
uma variação na vazão.
resultados de cálculos.
23
ARTIGOS TÉCNICOS
Feito a verificação na geometria, faz-se então geração da malha de elementos finitos tetraédricos para diferentes posições de
Tabela- 2 – Condições de Contorno para cálculo do
modelo do sistema de controle de vazão
abertura da válvula, com refinamento em áreas de interesse que,
neste caso na saída do tubo de sucção, conforme mostrado na
Figura 4.
Durante o ensaio experimental, foram determinadas várias posições de abertura da válvula, porém o cálculo em CFD nos permite
obter o mesmo resultado utilizando uma menor amostragem, sendo então considerados 6 pontos mais significativos para a simulação.
3 CÁLCULO NUMÉRICO
Após definição das condições de contorno, é possível fazer o cálculo numérico utilizando o “CFX solver”. A tabela 3 mostra os modelos matemáticos adotados para o cálculo.
Figura 4 – Estrutura da malha formada por elementos tetraédricos
Tabela 3 – Modelos usados para o cálculo
2.2.2.Condições de Contorno
As condições de contorno na entrada são dadas em função da
velocidade do escoamento, considerando as direções radial, tan-
O modelo de turbulência RNG k-ε adotado neste trabalho, é ca-
gencial e axial. Para as superfícies que delimitam a saída do fluido,
paz de identificar altas e baixas escalas de turbulência e detectar
considera-se a variação da vazão em função da abertura do siste-
os refluxos em superfícies curvas. Para cálculo, considerou-se a
ma, representado na figura 5.
equação 2, definida a partir da Lei da Continuidade, mantendo a velocidade constante, variando a vazão de acordo com a variação na
área de saída do tubo de sucção.
Onde Dts é o diâmetro na saída do tubo de sucção [mm], Do é o
diâmetro do obturador cônico em cada posição de abertura [mm] e
V é a velocidade do escoamento na entrada do tubo.
Figura 5- Condições de contorno
4 ANÁLISE DOS RESULTADOS
4.1.Pressão
A tabela 2 mostra as condições de contorno, considerando a
A figura 6 mostra a distribuição de pressão estática média ao
velocidade do escoamento nas projeções radial, tangencial e axial,
longo do tubo de sucção, considerando pontos de máxima e míni-
respectivamente, Vr, Vu and Vz na entrada do modelo do tubo de
ma aberturas.
sucção.
Em particular, considerou-se o domínio físico como sendo apenas a água, portanto se não considerando o efeito do ar.
Para a entrada do tubo de sucção na condição de operação considera-se uma vazão máxima (Q) de 0,0301 [ m³ / s] e velocidade
de rotação da bomba funcionando como turbina- BFT, constante de
1800 [rpm]. Para a Pressão Estática adotada na saída do modelo,
Pout [Pa], considera-se o efeito do nível de água a jusante, esse valor pode ser calculado pela equação 1:
Figure 6 - Pressão média apurada máxima e mínima
Onde h1 se refere a diferença entre o eixo horizontal da BFT em
A partir da distribuição da pressão, observa-se que as pressões
relação a superfície livre, ou seja, o nível da água do tanque na saí-
mais elevadas ocorrem na parede do tubo de sucção, logo na en-
da do tubo de sucção, y e step são, respectivamente, a variável e a
trada devido a contribuição da parcela dinâmica da pressão com a
função interna dada pelo software ANSYS CFX para o cálculo em
componente tangencial da velocidade do escoamento, principal-
CFD;(step é unitário quando y>h1)e g é a aceleração da gravidade.
mente detectável nas menores aberturas do obturador.
24
TECHNICAL ARTICLE
A Figura 7 mostra os pontos adotados ao longo do tubo de sucção, cujo posicionamento é definido apenas de maneira representativa.
Figure 7- Pontos de pressão ao longo do tubo de sucção
Os gráficos apresentados nas Figuras 8 e 9 mostram a variação
da pressão, nas seções demarcadas ao longo do tubo de sucção,
mostrado na Figura7, para aberturas mínimas e máximas.
Figura 10 – Velocidade de Escoamento definida em [m/s]
para aberturas máximas e mínimas
4.3 Vetores Velocidade
A Figura 11 mostra a distribuição do vetor velocidade na entrada do tubo, mostrando o direcionamento do fluxo.
Figure 8 - Pontos de P ao longo do tubo para abertura mín. de 120 mm
Observa-se que o gráfico representado pela Figura 8 mostra a
Figura 11 – Detalhamento do Vetor Velocidade na entrada do
tubo para máxima e mínima aberturas
flutuação de pressão induzida pelo movimento de rotação do rotor,
diminuindo com o aumento da distância do ponto referenciado na
5 CONCLUSÕES
entrada do tubo de sucção.
Com os resultados obtidos através da análise da aplicação numérica em CFD (Dinâmica do Fluido Computacional), mostrados
nas Figura 6, observa-se pequenas variações da pressão ao longo
do tubo de sucção, sendo essas variações mais concentradas na entrada do tubo devido a parcela dinâmica da pressão com a componente tangencial da velocidade do escoamento.
A Figura 10, indica uma diminuição da velocidade ao longo do
tubo. Isso ocorre devido a obstrução da passagem da água na saída do tubo de sucção devido a instalação do obturador para o controle de vazão , mostrando através da simulação numérica que a
Figura 9 - P ao longo do tubo de sucção para abertura máx. de 283 mm
O gráfico representado pela Figura 9 mostra a tendência crescente, justificando a recuperação de pressão ao longo do tubo de
sucção.
partir da abertura ou fechamento do sistema é possível fazer o controle da velocidade de rotação, como observado nos ensaios experimentais.
Pode-se observar, a partir da Figura 11, trechos de recirculação
ou vórtices mais concentrados na entrada do tubo de sucção, resul-
4.2.Velocidade de Escoamento
tantes da diferença de pressão devido a rotação do rotor da BFT.
A figura 10. representa a distribuição da velocidade média de
O modelo desenvolvido permite, a partir destas condições de
escoamento ao longo do tubo de sucção, para aberturas máximas e
contotno simular o comportamento do escoamento paar diferentes
mínimas do obturador.
posição e formatos do obturador, tornado-se uam ferramenta para
De acordo com a abertura do SISCOV, ocorre um aumento gradativo na componente axial da velocidade de escoamento ao longo
do tubo, caracterizando o aumento da vazão (Figuras 10), sendo es-
a otimização do sitema de controle de vazão e, por extensão, de
controle de velocidade do grupo gerador.
O resultado final é a busca de um sistema de baixo custo e com
sa velocidade maior no local de menor área, ou seja, na entrada do
operação segura para grupos geradores de pequeno porte despro-
tubo. As Figuras demonstram que a velocidade do escoamento no
vidos de distribuidor, com é o caso de bombas funcionando com tur-
tanque de jusante são pequenas face a proporção existente entre o
binas- BFTs, entre outros tipos de micro-turbinas.
mesmo e o tubo de sucção.
25
ARTIGOS TÉCNICOS
6 AGRADECIMENTOS
NETO H. J., ALENCAR H. S., BERNARDES M. E. C., SILVA F. G. B.
Os autores agradecem ao CERPCH e à UNIFEI que propiciaram
(2008), “Modelagem e Simulação do Comportamento de um
os meios para o desenvolvimento deste equipamento e à Alstom os
Válvula de Fluxo Hidráulica com Uso
meios para simulação do modelo computacional.
Hidroinformática”Ver. Tecnol. Fortalaleza, v.29, n. 2, p 224-232.
de Ferramenta de
SANTOS P. C, (2009), “Estudo de um Sistema de Controle de
7 REFERÊNCIAS BIBLIOGRÁFICAS
Vazão Utilizando a Dinâmica de fluido Computacional: Metodologia
ALENCAR H. S, (2007), “Estudo Numérico da Termo-
e Prática”, Universidade Federal de Itajubá, Itajubá-MG, p.123.
Aerodinâmica de Câmaras de Combustão para Turbinas a Gás:
VIANA A. N. C. (1987), “Comportamento de Bombas
Aplicação ao caso de Micro Turbinas”, Universidade Federal de
Centrífugas Funcionando como Turbinas Hidráulicas”, Dissertação
Itajubá, Itajubá-MG, p.151.
de Mestrado, EFEI, Itajubá/ MG, pp. 95.
ALENCAR H. S, (1999), “Análise do Comportamento de
Turbinas
Hidráulicas
para
Operar
com
Rotação
Variável”,
Universidade Federal de Itajubá, Itajubá-MG, p.210.
BALARIM C. R., TARGA L. A.,FILHO J. S. V., ANDRADE A. G.,
WIECHETECK G. K. (2004) , “Custo de Bombas Funcionando como
VIANA A. N. C., “Bombas de Fluxo Operando como Turbinas.Por
que Usá-las?”, Artigo Técnico, EFEI, Itajubá/ MG, pp.13.
VIANA A. N. C., NOGUEIRA F. J. H.(1990), “Bombas Centrífugas
Funcionando como Turbinas”, Trabalho de Pesquisa, Departamento
de Mecânica, EFEI, Itajubá/ MG.
Turbinas em Microcentrais Hidrelétricas”, Artigo Técnico, Eng.
Agric, Jaboticabal, p.219-225.
10
www.cerpch.org.br
www.cerpch.org.br
26
TECHNICAL ARTICLE
THE STUDY OF ACTIVE FLOW CONTROL IN FRANCIS TURBINES
Roland Wunderer1
2
Rudolf Schilling
ABSTRACT
Hydro Turbines are being operated on very high levels of efficiency, characterised by peak efficiencies beyond 95%. Thus, the margin
of further increasing the efficiencies in the best point of operation and in the vicinity of it is very small. However, considering operating
points under part load and over load conditions the efficiency drop may be very high, especially for turbines with higher specific speeds.
This phenomenon is combined with a strong increase of pressure pulsations decreasing the life endurance limit of turbines.
To reduce the time-dependent pressure loading of Francis turbine runners several possibilities of active flow control have been studied
and the most promising solution is to generate guide vane blades pitching with variable frequencies and amplitudes. To investigate this
fluid flow problem in detail and to work out the optimum combination of frequency and amplitude for a given test case, a LES code has
been developed and applied to solve this problem.
The paper shows simulation results for a 2D tandem cascade for different relevant parameters. Considering the tandem cascade flow,
the overall losses may be reduced considerably by a pitching inlet cascade. Depending on the frequency and amplitude of the pitching profiles the amplitude of the pressure pulsations may also be diminished as well as their characteristic frequencies may be shifted towards
lower or higher values. Thus, a resonance effect may be avoided by modifying the pitching frequency.
Unsteady flow computations are carried out considering a model Francis Turbine having a specific speed nq = 85 l/min, to study the influence of pitching guide vanes with respect to frequency and amplitude on the efficiency as well as on the pressure amplitudes.
Key words: active flow control, hydraulic turbines, detached eddy simulation, computational fluid dynamics, hybrid differencing, boundary layer shielding
INTRODUCTION
An efficient 3D transient Navier-Stokes code, based on a Finite
Francis turbines are characterized by peak efficiencies beyond
Volume formulation, was developed. The linearized system of mo-
95%. This is only valid in the best point of operation. However in
mentum- and continuity equations is solved by a modified version
part and over load the efficiency drops significantly. Furthermore
of the PISO pressure correction scheme, which original formulation
pressure pulsations can be observed in this operation points. In
was described by ISSA [2]. With this code several simulations were
large Francis turbines the pulsations can cause very large resulting
done, to investigate the physical details of the transient flow and
forces on the runner blades. These forces can impair the life endur-
the effects of the active flow control in a turbine under part load con-
ance of the runner blades and therefore damage them in the long
ditions.
run. Damage may also occur, if the fluctuations stimulate the tur-
The need to simulate pitching airfoils required to handle mesh
bine with its eigenfrequency. To avoid damages and expensive re-
deformation.
pairs, the turbines are switched off in the case of extremely water
FERZIGER, PERIC [1], which modifies the fluxes in the Navier-
levels.
Stokes equations in the case of mesh deformation, was imple-
For both effects, the drop of efficiency and the pressure pulsa-
Therefore
the
space
conservation
law,
see
mented. For efficiently and accurately mesh deformation, an algo-
tions, the reason is a highly transitional flow in the rotor. At the lead-
rithm has been developed. It is based on an algebraic formulation
ing edges of the rotor blades a strong separation can occur, which is
and works without solving any extra partial differential equations.
the main cause for the transitional flow character.
The algorithm was optimized for the problem of pitching airfoils
Active flow control can reduce this separation and therefore in-
and the validation regarding mesh quality showed, that it was supe-
crease the efficiency and modify the pressure pulsations, regard-
rior to Finite Volume and Finite Element approaches for this kind of
ing amplitude reduction and frequency shifting. By pitching the
problem. The algorithm is described in WUNDERER [14].
guide vanes periodically, a time varying flow onto the runner
blades is created which affects the separation in the desired way.
DES models
For the investigation of these phenomenons numerical simula-
Preliminary simulations showed that the physical effects, that
tions were done. Therefore a hybrid turbulence modelling, namely
should be studied, could not be resolved with a Reynolds Averaged
Detached Eddy Simulation (DES) was applied. Some modifications
Navier-Stokes (RANS) simulation, WUNDERER [15]. The desired
regarding the underlying DES-model and the handling of the
accuracy can be achieved with a Large Eddy Simulation (LES). How-
discretization of the advection terms were done. Thus it was man-
ever classical LES needs to resolve the wall near domain very accu-
aged to apply DES for the flow in turbo-machines.
rately. The resolution is dependent on the Reynolds number of the
flow. PIOMELLI, BALARAS [6] showed, that the number of cells, re1.8
NUMERICAL MODEL
quired to resolve just the inner part of the boundary layer is ~Re .
CFD code
The time step has to be adapted accordingly. In technical flows of
1 Institute of Fluid Mechanics - Institute of Fluid Mechanics - Germany - e-mail: [email protected]
2 Institute of Fluid Mechanics - Institute of Fluid Mechanics - Germany - e-mail: [email protected]
27
ARTIGOS TÉCNICOS
6
the kind studied here, Reynolds numbers of ~10 are examined.
However CDS is less stable than UDS. Among other things this can
The required computing power is far-off today´s available re-
be caused by nonuniform grids or too high cell Reynolds numbers.
sources. There fore it is necessary to model the boundary layer.
To combine the advantages of both schemes, TRAVIN et al.
Most promising for that task is the DES, which uses a hybrid tur-
[11] developed a hybrid differencing scheme that blends the fluxes
bulence model acting as a RANS model in the boundary domain and
calculated both by a CDS and a UDS. The blending function
a LES subgrid scale (SGS) model outside it. The switching between
switches between a UDS near the walls and in the domains where
the two modes is done by the model itself. Some DES where vali-
the turbulence intensity as well as the transient character of the
dated e.g. in WUNDERER [15]. For the following calculations the
flow is low and a CDS elsewhere. The blending of the fluxes F is
SST-DES model was chosen. The equations for that model are
done in the following way:
shown e.g.in MENTER,KUNTZ[4] or WUNDERER, SCHILLING [16].
Boundary layer shielding
The blending function s is defined as follows:
The major drawback of the original DES formulation is the grid
dependency of the mechanism for switching between the LES and
the RANS mode of the model. To achieve good results the grid has
to be adapted exactly to the given flow. To avoid that problem several shielding mechanisms for the boundary layer have been developed, see eg. MENTER, KUNTZ[4] or SPALART et al.[8]. Independent of the grid quality these mechanisms should prevent the model
from switching to the LES mode in domains where the RANS mode
should be active, especially in the wall near domains. In
WUNDERER, SCHILLING [16] an adaptation of the shielding for the
The calculation of the turbulent length scale differs slightly
SST-DES model was done. The formulation of the DES-limiter
from the original formulation of TRAVIN et al. [11] and STRELETS
FDES for the model is:
[9]. This type of blending works well for flows around bodies, e.g.
in aerodynamic applications. These applications are characterized
by a laminar or low turbulent flow, that separates somewhere at a
body and then changes to a turbulent flow. For these kinds of problems the DES was primarily developed.
The flow in turbo-machines is characterized by a different character. The flow is already turbulent when it enters the domain of interest, e.g. the runner. Therefore the above blending does a bad
The advantage of this new formulation is its applicability for in-
job, as the high values of turbulent kinetic energy in the whole flow
ternal turbulent flows, as in turbo-machines. It ensures, that the
domain prevents the blending mechanism from switching in the
RANS mode of the model is activated just inside the boundary
UDS mode. In Fig. 3 vectors of the relative velocity, plotted on a
layer, whereas the LES mode is activated outside it. The common
plane section through a turbine runner are visualized. The flow be-
method of shielding the SST-model activates the RANS mode in a
fore the blades is of steady state type in the rotating system. At the
much too large flow domain. A comparison of both methods can be
leading edges of the blades the flow separates and forms a large
seen in Fig. 1 and 2. More details are shown in WUNDERER, SCHIL-
vortex. The mesh for the simulation was designed in a way to
LING [16].
achieve good mesh quality within the rotor domain. The mesh-cells
before the blades are comparatively large, whereas the cells behind the blades are very flat. In Fig. 5 the values of the blending factor s, calculated by the above equations 3, are shown. It can be
seen that s is close to zero, what means, that the discretization is
blended to CDS in nearly the whole flow domain. As the flow before
Fig.1: Model mode for the flow in a blade row, with the
new shielding, regarding equation 1.
Fig. 2: Model mode for the flow in a blade row, with the shielding,
proposed by MENTER, KUNTZ [4].
Hybrid differencing
For LES or LES-like simulations as DES or SAS, see MENTER,
EGOROV [5], the discretization scheme should be of centraldifferencing type (CDS). This is due to the fact that centraldifferencing schemes are less dissipative than upwind schemes
(UDS) and thus full advantage of the grid provided can be taken.
28
Fig. 3: Vectors of the relative velocity, plotted
on a plane section through a radial turbine.
TECHNICAL ARTICLE
6
the blades is nearly of steady state type and the mesh after the
The mesh consists of ~1×10 cells. A mesh study, which can be
blades is of poor quality for LES, in these regions UDS should be
seen in WUNDERER [15], showed that this resolution was ade-
blended.
quate for the simulations. The flow analysis has been done on three
For that reason a modifaction of the above blending function
sections:Section 0 was placed upstream the first blade row, section
was developed. The blending is done in a way that regions with a
1 between the two rows and section 2 downstream the second row.
high transient flow character are preferred for the CDS. Additionally the influence of the grid is taken into account, what means,
that mesh regions of poor quality are discretized by UDS. In the following equations tmin and tmax are representative convection
times of a cell. This can e.g. be the minimum and maximum time of
the flow needed to pass a cell. The modified blending is described
bellow. In Fig. 4 it can be seen that the blending works as desired.
The flow within the runner is dominated by CDS, whereas outside
the runner there is added some amount of UDS. The new blending
function is defined as follows:
Fig. 6: Geometry of the simplified turbine model.
RESULTS
Fixed guide vanes
The unsteady character of the flow can be seen in Fig. 15,
where the streamlines plotted on a plane section are shown. A sequence of the separation process for the case with fixed front
blades can be seen there. In Fig. 7 the time varying forces, normal
to one of the back blades are shown. Clearly the fluctuations of the
forces, which are due to the unsteadiness of the flow, can be observed. The time dependent values of the normal forces are within
±30% of the mean force. These fluctuations are the main cause for
the damage of a turbine blade in the long time run.
The frequency analysis of the time row shows two characteristic peeks, s. Fig. 8. The first one at k = 3.125, which is the frequency of the separation, the second one at k = 6.25, which is the
first harmonic. The reduced frequency k calculates as follows:
The separation is not comparable with the separation at a single airfoil, as it is described e.g. in WUNDERER [15]. This is due to
the fact, that there is the effect of additional blades on the flow.
First the blades bound the size of the separation to a maximum
value. Secondly the separation affects the flow in a positive way, as
it transports fluid downwards by its rotation. This amplifies the direction change of the flow and leads to a nearly blade congruent
Fig.4: Blending factor for the discretization, calculated by the new
formula, according to equations 4.
Fig. 5: Blending factor for the discretization, calculated by equations 3,
TRAVIN et al. [11].
Simplified model of a turbine
flow in this case, as can be seen in Fig. 15.
Pitching guide vanes
To study the dynamic behaviour, the front blades where pitched
For studying the basic effects an abstract model of a radial tur-
with various frequencies and amplitudes. In Fig. 9 the effect on the
bine was chosen. It consists of two blade rows, the first corre-
total pressure drop from section 0 to section 2 is shown. A positive
sponding to the guide vanes and the second corresponding to the
effect on the pressure drop can be seen for various frequencies and
runner. It is equivalent to a radial turbine with a very large diame-
amplitudes. The pressure drop is reduced mostly at k = 3.125. This
ter. As the two bladings are fixed, the flow corresponds to the rela-
corresponds to the frequency of the vortex-separation at the lea-
tive flow in a radial turbine. The front blades are turned about -10°
ding edges of the blades. As can be seen, the total pressure drop is
and the back blades about 37°. The model can be seen in Fig. 6.
reduced about 22%.
29
ARTIGOS TÉCNICOS
Since the hydraulic efficiency of a turbine is proportional to
1/Dpt, the reduction of the total pressure drop results in a higher efficiency. The sequences in Fig. 15 show the reason for this behaviour. It can be seen that in the pitching case there is still a separation, which is more regular and somewhat smaller than in the static
case. This means that there is a larger area for the fluid to pass
through, which results in a lesser total pressure drop.
For reducing the losses in the blade row, there is to put energy
into the system by pitching the front blades. If this energy input is
taken into account, the energy balance has to show a higher net energy drop, than the one in Fig. 9. The net energy drop is the total
pressure drop additionally the energy needed for pitching the front
blades. The net energy drop is shown in Fig. 10.
Fig. 7: Dimensionless normal forces on a back blade,
arrangement with fixed guide vanes.
The net values are similar to the ones of Fig. 9, what means,
that the energy for pitching the front blades is small compared to
the reduction of the losses. For the optimum values, k = 3.125 and
Da = 2.75°, a reduction of the net energy drop of about 20% can be
achieved for this case.
In Fig. 11 the variation of the flow turning from section 0 to section 2, described by DUy, is shown. For all configurations the variation is smaller than 5%. This small value is due to the fact, that
there is almost a blade congruent flow off the trailing edge, in the
case of fixed front blades. Therefore the turning of the flow cannot
be further improved. The reason for this behaviour is the separation at the upper side of the blade which transports fluid downwards by its rotation. The velocity component Uy corresponds to
Fig. 8: Frequency analysis of the dimensionless normal force fluctuations,
arrangement with fixed guide vanes.
the peripheral velocity cu in a radial turbine. As the hydraulic efficiency of a turbine is proportional to D(rcu), it can be expected that
the effect of the velocity variation is minor compared to the reduction of the pressure drop and the influence on the efficiency is dominated by the total pressure drop.
Another positive effect can be seen in Fig. 12. Compared to Fig.
7 the deviation from the mean force is reduced. This concerns both
the maximum and the mean deviation. In this time series the reduction is about 25% of the maximum deviation.
There can also be observed an effect on the frequency of the
separation and therefore on the frequency of the blade normal
forces in the second row. Fig. 13 and 14 show that the dominant frequency of the blade normal forces can be shifted to the pitchingfrequency of the guide vanes. This effect could be utilized in cases
where the frequency of the pressure fluctuations is about the
Fig. 9: Total pressure drop, from section 0 to 2, relative to the
case with fixed guide vanes.
eigenfrequency of a turbine, what could cause seriously damage.
CONCLUSIONS
The simulations of the simplified turbine model showed that
guide vanes, pitching with appropriate frequencies and amplitudes, could reduce the total pressure drop in radial turbines. In extreme part and overload conditions this could increase the efficiency of the turbine considerably.
Furthermore a positive effect regarding the pressure fluctuations can be noticed. The fluctuations of the blade forces can be reduced, which would result in a remarkable increase of the lifespan
of turbines.
It is also possible to shift the frequency of the pressure fluctuations towards the frequency of the pitching guide vanes. This can
Fig. 10: Net drop of total pressure, from section 0 to 2, relative to the
case with fixed guide vanes.
30
be useful in operation points where the pressure fluctuations could
TECHNICAL ARTICLE
stimulate the turbine at its eigen frequency.
In the meantime simulations have been started to study the
time-dependent flow in the stage of the Francis Turbine FT 85, having pitching guide vanes. The already existing results show, that
the described effects can be applied to real turbines.
REFERENCES
[1] FERZIGER, J.H. ; PERIC, M.: 2002, Computational Methods
for Fluid Dynamic, Springer, Berlin Heidelberg
[2] ISSA, R.I.: 1986, Solution of implicitly discretized fluid flow
equations by operator-splitting, Journal of Computational Physics,
62, p. 40-65
Fig.11: Flow turning DUy, from section 0 to 2, relative to the
value of the fixed case.
[3] LEDER, A.: 1992, Abgelöste Strömungen Physikalische
Grundlagen, Vieweg, Braunschweig/Wiesbaden
[4] MENTER, F. R.; KUNTZ, M.: 2004, Development and application of a zonal DES turbulence model for CFX-5, ANSYS CFX
Validation Report
[5] MENTER, F. R. ; EGOROV, Y.: 2005, A scale-adaptive simulation model using two-equation models, AIAA Paper 2005-1095
[6] PIOMELLI, U.; BALARAS, E.: 2002, Wall-Layer Models for
Large-Eddy Simulations, Annual Review of Fluid Mechanics 34, p.
349-374
[7] SPALART, P. R. ; JOU, W. H. ; STRELETS, M. ; ALLMARAS, S.
R.: 1997, Comments on the feasibility of LES for wings, and on a
hybrid RANS/LES approach, 1st AFOSR Int. Conf. on DNS/LES,
Aug. 4-8, 1997, Ruston, LA. In: Advances on DNS/LES, C. Liu and
Z. Liu Eds., Greyden Press, Columbus, OH, USA
Fig.12: Dimensionless normal forces on a blade of the second blade row,
with pitching guide vanes.
[8] SPALART, P. R.; DECK, S.; SHUR, M. L.; SQUIRES, K. D. ;
STRELETS, M. Kh. ; TRAVIN, A.: 2006, A new version of detachededdy simulation, resistant to ambiguous grid densities, Theor.
Comput. Fluid Dyn. (2006) 20: 181-195 [9] STRELETS, M.: 2001,
Detached Eddy Simulation of Massively Separated Flows, AIAA
Paper 2001-0879
[10] TELIONIS, D. P.: 1981, Unsteady viscous flows, Springer,
New York, Heidelberg, Berlin
[11] TRAVIN, A. ; SHUR, M. ; STRELETS, M. ; SPALART, P.R.:
2000, Physical and numerical upgrades in the detached-eddy simulation of complex turbulent flows, Proceedings of the Euromech
Colloquium on LES of Complex transitional and turbulent flows,
Munich, Oct. 2000
[12] WERDECKER, F.: 2000, Strömungswechselwirkung an ei-
Fig.13: Frequency analysis of the normal force for k=1.56,
compared to the fixed case.
nem Tandemgitter mit schwingender Vorleitschaufel, Diss.,
Technische Universität München
[13] WUNDERER, R.: 2006, Aktive Strömungsbeeinflussung,
Zwischenbericht zum Projekt KW21
[14] WUNDERER, R.: 2007, Algebraischer Algorithmus für die
Netzdeformierung, internal report, Institute of Fluid Mechanics,
Technische Universität München
[15] WUNDERER, R.: 2007, Aktive Strömungsbeeinflussung,
Abschlußberichtbericht zum Projekt KW21
[16] WUNDERER, R. ; SCHILLING, R.: 2008, Numerical
Simulation Of Active Flow Control In Hydro Turbines, ISROMAC-12
: 12th International symposium on transport phenomena and dynamics of rotating machinery
Fig.14: Frequency analysis of the normal force for k=6.25,
compared to the fixed case.
31
INSTRUCTIONS FOR AUTHORS
TECHNICAL ARTICLES
INSTRUÇÕES AOS AUTORES
Forma e preparação de manuscrito
Form and preparation of manuscripts
Primeira Etapa (exigida para submissão do artigo)
O texto deverá apresentar as seguintes características: espaçamento
First Step (required for submition)
The manuscript should be submitted with following format: should be
1,5; papel A4 (210 x 297 mm), com margens superior, inferior, esquerda e dire-
typed in Times New Roman; 12 font size; 1.5 spaced lines; standard A4 paper
ita de 2,5 cm; fonte Times New Roman 12; e conter no máximo 16 laudas, in-
(210 x 297 mm), side margins 2.5 cm wide; and not exceed 16 pages, includ-
cluindo quadros e figuras.
Na primeira página deverá conter o título do trabalho, o resumo e as
ing tables and figures.
In the first page should contain the title of paper, Abstract and Keywords.
Palavras-Chaves. Nos artigos em português, os títulos de quadros e figuras de-
For papers in Portuguese, the table and figure titles should also be written in
verão ser escritos também em inglês; e artigos em espanhol e em inglês, os tí-
English; and papers in Spanish and English, the table and figure titles should
tulos de quadros e figuras deverão ser escritos também em português. Os qua-
also be written in Portuguese. The tables and figures should be numbered con-
dros e as figuras deverão ser numerados com algarismos arábicos consecuti-
secutively in Arabic numerals, which should be indicated in the text and an-
vos, indicados no texto e anexados no final do artigo. Os títulos das figuras de-
nexed at the end of the paper. Figure legends should be written immediately
verão aparecer na sua parte inferior antecedidos da palavra Figura mais o seu
below each figure preceded by the word Figure and numbered consecutively.
número de ordem. Os títulos dos quadros deverão aparecer na parte superior
The table titles should be written above each table and preceded by the word
e antecedidos da palavra Quadro seguida do seu número de ordem. Na figura,
Table followed by their consecutive number. Figures should present the data
a fonte (Fonte:) vem sobre a legenda, à direta e sem ponto-final; no quadro,
source (Source) above the legend, on the right side and no full stop; and ta-
na parte inferior e com ponto-final.
O artigo em PORTUGUÊS deverá seguir a seguinte seqüência: TÍTULO em
bles, below with full stop.
The manuscript in PORTUGUESE should be assembled in the following or-
português, RESUMO (seguido de Palavras chave), TÍTULO DO ARTIGO em in-
der: TÍTULO in Portuguese, RESUMO (followed by Palavras-chave), TITLE in
glês, ABSTRACT (seguido de key words); 1. INTRODUÇÃO (incluindo revisão
English; ABSTRACT in English (followed by keywords); 1.INTRODUÇÃO (in-
de literatura); 2. MATERIAL E MÉTODOS; 3. RESULTADOS E DISCUSSÃO; 4.
cluding references); 2. MATERIAL E MÉTODOS; 3. RESULTADOS E
CONCLUSÃO (se a lista de conclusões for relativamente curta, a ponto de dis-
DISCUSSÃO; 4. CONCLUSÃO (if the list of conclusions is relatively short, to
pensar um capítulo específico, ela poderá finalizar o capítulo anterior); 5.
the point of not requiring a specific chapter, it can end the previous chapter);
AGRADECIMENTOS (se for o caso); e 6. REFERÊNCIAS, alinhadas à esquerda.
O artigo em INGLÊS deverá seguir a seguinte seqüência: TÍTULO em in-
5. AGRADECIMENTOS (if it is the case); and 6. REFERÊNCIAS, aligned to the
The article in ENGLISH should be assembled in the following order: TITLE
RESUMO (seguido de Palavras-chave); 1. INTRODUCTION (incluindo revisão
in English; ABSTRACT in English (followed by keywords); TITLE in Portuguese;
de literatura); 2. MATERIALAND METHODS; 3. RESULTS AND DISCUSSION; 4.
ABSTRACT in Portuguese (followed by keywords); 1. INTRODUCTION (includ-
CONCLUSIONS (se a lista de conclusões for relativamente curta, a ponto de
ing references); 2. MATERIAL AND METHODS; 3.RESULTS AND DISCUSSION;
dispensar um capítulo específico, ela poderá finalizar o capítulo anterior); 5.
4. CONCLUSIONS (if the list of conclusions is relatively short, to the point of
ACKNOWLEDGEMENTS (se for o caso); e 6. REFERENCES.
O artigo em ESPANHOL deverá seguir a seguinte seqüência: TÍTULO em
not requiring a specific chapter, it can end the previous chapter); 5. AC-
espanhol; RESUMEN (seguido de Palabra llave), TÍTULO do artigo em portu-
KNOWLEDGEMENTS (if it is the case); and 6. REFERENCES.
The article in SPANISH should be assembled in the following order:
guês,
1.
TÍTULO in Spanish; RESUMEN (following by Palabra-llave), TITLE of the article
INTRODUCCTIÓN (incluindo revisão de literatura); 2. MATERIALES Y
in Portuguese, ABSTRACT in Portuguese (followed by keywords); 1.
METODOS; 3. RESULTADOS Y DISCUSIÓNES; 4. CONCLUSIONES (se a lista
INTRODUCCTIÓN (including references); 2. MATERIALES Y MÉTODOS; 3.
de conclusões for relativamente curta, a ponto de dispensar um capítulo espe-
RESULTADOS Y DISCUSIÓNES; 4. CONCLUSIONES (if the list of conclusions is
cífico, ela poderá finalizar o capítulo anterior); 5. RECONOCIMIENTO (se for o
relatively short, to the point of not requiring a specific chapter, it can end the
caso); e 6. REFERENCIAS BIBLIOGRÁFICAS.
Os subtítulos, quando se fizerem necessários, serão escritos com letras
previous chapter); 5.RECONOCIMIENTO (if it is the case); and 6.
RESUMO
em
português
(seguido
de
palavras-chave);
iniciais maiúsculas, antecedidos de dois números arábicos colocados em posição de início de parágrafo.
No texto, a citação de referências bibliográficas deverá ser feita da se-
REFERENCIAS BIBLIOGRÁFICAS.
The section headings, when necessary, should be written with the first letter capitalized, preceded of two Arabic numerals placed at the beginning of the
guinte forma: colocar o sobrenome do autor citado com apenas a primeira le-
paragraph.
Abstracts should be concise and informative, presenting the key points of
tra maiúscula, seguido do ano entre parênteses, quando o autor fizer parte do
the text related with the objectives, methodology, results and conclusions; it
texto. Quando o autor não fizer parte do texto, colocar, entre parênteses, o so-
should be written in a sequence of sentences and must not exceed 250 words.
References cited in the text should include the author\'s last name, only
brenome, em maiúsculas, seguido do ano separado por vírgula.
O resumo deverá ser do tipo informativo, expondo os pontos relevantes
ARTIGOS TÉCNICOS
left.
glês; ABSTRACT (seguido de Key words); TÍTULO DO ARTIGO em português;
with the first letter capitalized, and the year in parentheses, when the author
do texto relacionados com os objetivos, a metodologia, os resultados e as con-
is part of the text. When the author is not part of the text, include the last
clusões, devendo ser compostos de uma seqüência corrente de frases e con-
name in capital letters followed by the year separated by comma, all in paren-
ter, no máximo, 250 palavras.
Para submeter um artigo para a Revista PCH Noticias & SHP News o(os)
theses
For paper submission, the author(s) should access the online submission
autor (es) deverão entrar no site www.cerpch.unifei.edu.br/Submete-rartigo.
Serão aceitos artigos em português, inglês e espanhol. No caso das lín-
Web site www.cerpch.unife.edu.br/submeterartigo (submit paper).
The Magazine SHP News accepts papers in Portuguese, English and Span-
guas estrangeiras, será necessária a declaração de revisão lingüística de um
ish. Papers in foreign languages will be requested a declaration of a specialist
especialista.
in language revision.
Segunda Etapa (exigida para publicação)
O artigo depois de analisado pelos editores, poderá ser devolvido ao (s)
autor (es) para adequações às normas da Revista ou simplesmente negado
Second Step (required for publication)
After the manuscript has been reviewed by the editors, it is either re-
por falta de mérito ou perfil. Quando aprovado pelos editores, o artigo será en-
turned to the author(s) for adaptations to the Journal guidelines, or rejected
caminhado para três revisores, que emitirão seu parecer científico. Caberá
because of the lack of scientific merit and suitability for the journal. If it is
ao(s) autor (es) atender às sugestões e recomendações dos revisores; caso
judged as acceptable by the editors, the paper will be directed to three review-
não possa (m) atender na sua totalidade, deverá (ão) justificar ao Comitê
ers to state their scientific opinion. Author(s) are requested to meet the re-
Editorial da Revista.
viewers\' suggestions and recommendations; if this is not totally possible,
they are requested to justify it to the Editorial Board
Obs.: Os artigos que não se enquadram nas normas acima descritas, na
sua totalidade ou em parte, serão devolvidos e perderão a prioridade da ordem seqüencial de apresentação.
Obs.: Papers that fail to meet totally or partially the guidelines above described will be returned and lose the priority of the sequential order of presentation.
32
AGENDA/SCHEDULE
Wind Fórum Latam 2010
Data: 27 e 28 de julho de 2010
Local: Continental Hotel, Buenos Aires - Argentina
Site: www.windforumlatam.com
Smart Grid 2010 - III Fórum Latino-Americano de Smart
Grid
Hydro World Weekly
Data: 23 a 24 de agosto de 2010
Data: 27 a 30 de Julho de 2010
Local: Novotel Jaraguá São Paulo Conventions - São Paulo
Local: Charlotte, NC USA
Site: http://www.smartgrid.com.br/
Site: www.hydroevent.com
Biomass Investing
MecShow-Feira de Metalmecânica, Energia e Automação
Data: 24 a 26 de agosto de 2010
Data: 28 a 30 de julho de 2010
Local: São Paulo - SP
Local: Pavilhão de Carapina - Vitória - Espírito Santo
Site: www.iqpc.com.br
Site: www.mecshow.com.br
21° Congresso Apimec - O papel do mercado de capitais
CINASE - I Circuito Nacional do Setor Elétrico - Rio de Ja-
em um mundo sustentável
neiro
Data: 25 a 27 de agosto de 2010
Data: 03 a 04 de agosto de 2010
Local: Ouro Minas Palace Hotel - Belo Horizonte - BH
Local: Rio de Janeiro - RJ
Site: www.21congressoapimec.com.br
Site: http://www.cinase.com.br/
Infrastructure Investment World Brazil 2010
Energy Summit
Data: 30 agosto a 01 de setembro de 2010
Data: 3, 4 e 5 de agosto de 2010
Local: Sheraton Barra Hotel - Rio de Janeiro
Local: Windsor Barra Hotel - Av. Sernambetiba, 2630 - Bar
Site: http://www.terrapinn.com/2010/iiwbrasil/
Site: http://www.energysummit.com.br
VI Conferência de PCH Mercado & Meio Ambiente
11° Encontro Internacional de Energia
Data: 01 e 02 de setembro de 2010
Data: 09 a 10 de agosto de 2010
Local: São Paulo - SP
Local: Centro de Convenções Hotel Unique - São Paulo - SP
Site: http://www.conferenciadepch.com.br/
Site: www.fiesp.com.br/energia/
Brazil Windpower 2010 - Seminário & Feira
XXI Encontro Técnico AESABESP
Data: 31 de agosto a 02 de setembro de 2010
Data: 10, 11 e 12 de Agosto
Local: Rio de Janeiro
Local: Pavilhão Amarelo do Expo Center Norte - São Paulo
Site: http://www.brazilwindpower.org
Site: http://www.fenasan.com.br/
FIIEE - 13ª Feira Internacional da Indústria Elétrica e
Eletrônica - Minas Gerais
Data: 10 a 13 de agosto de 2010
Local: Expominas - Belo Horizonte - MG
Site: www.fiiee.com.br
5° Congresso Internacional de Bioenergia
Data: 10 a 13 de agosto de 2010
Local: Curitiba - PR - Brasil
Site: www.eventobioenergia.com.br
Expo Energia Renováveis 2010 - Exposição e Congresso
de Energia Renovável
Data: 18 a 21 de agosto de 2010
Local: Expo Center Norte - São Paulo - SP
Site: www.expoenergia.com.br
33
OPINIÃO
A Inovação Tecnológica nas Fontes Alternativas
Technological Innovations for Alternative Sources of Energy
Por Ricardo Pigatto
Translation Adriana Candal
Sem dúvidas este é o assunto do momento – Inovação Tecnológica para geração de energia elétrica.
No doubt this subject is under the spotlight today – Technological Innovation for electric energy generation.
O tema viabilidade econômica de empreendimentos oriundos de
The issue 'economic feasibility for enter-
fontes alternativas para geração de energia elétrica, deve ser ampla-
prises that generate electric energy from al-
mente discutido. Os projetos devem apresentar um fluxo de caixa
ternative sources' must be widely discussed.
que garanta uma receita suficiente para amortizar os empréstimos e
The projects must present a cash flow that
juros, além de remunerar adequadamente o capital próprio alocado
assures enough income to amortize the lo-
pelos acionistas.
ans and interests, in addition to compensate
Confesso que esta equação, atualmente, é de difícil equacionamento, haja vista que os valores de mercado para a venda da ener-
properly the capital allocated by the shareholders.
gia a ser gerada, base de sustentação para os project finance estão li-
I confess that this equation is difficult to solve today, given that
mitados pelo excesso de oferta e pela demanda ainda em recupera-
the market values for the sale of the energy that will be generated,
ção com relação à crise de mercado do segundo semestre de 2008.
which are the foundation for the Project Finance are limited by the ex-
Então, como resolver? Com redução dos custos nos investimentos
cess of offer and by the demand that is still recovering from the mar-
em obras e equipamentos. Como se reduz o investimento? Com mui-
ket crisis of the second semester of 2008. Then, what to do? There
ta evolução tecnológica.
must be a reduction in the investment cost in relation to civil works
O maior e mais destacado movimento neste sentido foi o da geração eólica, que deu um salto de competitividade a ponto de, neste
and equipment. How does one reduce investment? With a great deal
of technological evolution.
momento, competir com a venda de energia oriunda das PCHs. Claro
The largest and most highlighted movement towards this pro-
que temos um aspecto tributário que beneficia as eólicas e que as
blem was the wind generation, which soared up in terms of competi-
PCHs não possuem o mesmo benefício, entretanto é inegável o avan-
tiveness and, at this point, is competing against the sales of the
ço tecnológico em toda a cadeia produtiva das eólicas. Desde o de-
energy from SHPs. Of course there is a tributary aspect that benefits
senvolvimento dos projetos, fabricação dos equipamentos, rendi-
wind plants, but the SHPs do not have the same benefit. However, it
mentos, logísticas de construção e transporte e, principalmente,
is undeniable the technological advance along the wind plant pro-
uma sensível redução dos custos.
ductive chain. From the development of the projects, equipment ma-
No caso da biomassa, a evolução tecnológica no desenvolvimento das plantas de geração térmica nos últimos anos demonstra e cer-
nufacture, efficiency, construction and transport logistics and, mainly, a significant reduction in the costs.
tifica que se trata de geração qualificada e competitiva. O aumento
As far as biomass is concerned, technological evolution in the de-
do rendimento das caldeiras e o melhor tratamento na matéria prima
velopment of thermal generating plants over the past few years
(combustível) fizeram com que este tipo de geração mais do que du-
shows and certifies that it is a qualified and competitive generation.
plicasse sua participação na matriz brasileira.
The rise in the efficiency of the boilers and a better treatment of the
É chegada a vez das PCHs entrarem neste ritmo de evolução.
Comparativamente as PCHs perderam competitividade vis-à-vis su-
raw material (fuel) doubled the participation of this type of energy generation in the Brazilian energy matrix.
as irmãs renováveis por não terem, ao longo dos últimos anos, bus-
It is time for the SHPs to catch up with this evolution. Comparati-
cado uma significativa melhoria tecnológica. Estamos na fase das
vely, the SHPs lost competitiveness in relation to their renewable sis-
médias e baixas quedas o que significa que os custos dos equipa-
ters because they have not, along the years, searched for a signifi-
mentos e construção civil sejam maiores. Entretanto estes dogmas
cant technological improvement. We are going through the phase of
dos valores mais elevados devem ter um tratamento adequado, haja
medium and low heads, which means that the costs of the equip-
vista que se nada for feito a expansão do setor com PCHs será pífia e
ment and civil works are higher. However, these dogmas of higher va-
somente com aproveitamentos menores ou com CGHs.
lues must have an appropriate treatment, for if nothing is done the
É preciso repensar os critérios de projetos, e isso é evolução tecnológica, assim como estudar a possibilidade da padronização de turbinas e geradores garantindo economia de escala, tal como fazem os
expansion of the SHP sector will be insignificant and based only on
smaller potentials or with CGHs (lower than 1MW installed power).
It is necessary to re-think the criteria of the projects, and this is
chineses, bem como o uso de novos materiais, melhorar a logística
technological evolution, and study the possibility of standardizing tur-
de fornecimento e implantação. Por fim, esta evolução deverá rever-
bines and generators assuring the economy of scale, as the Chinese
ter em aumento da eficiência dos sistemas e redução dos custos de
do, as well as using new materials and improving supply and imple-
implantação, retornando as PCHs ao estado competitivo de onde nun-
mentation logistics. Finally, this evolution might become an increase
ca deveriam ter saído, por ser fonte de geração limpa, ambiental-
in the efficiency of the systems and a reduction in the implementati-
mente responsável e socialmente justa.
on costs, taking the SHPs back to a competitive condition, which they
A palavra de ordem para as PCHs, daqui para frente, é inovação
tecnológica com redução de custos. Este é um grande desafio no
qual não podemos fugir.
should have never left from, because they are a clean, environmentally responsible and socially fair source of generation.
The key expression for SHPs from now on is technological innovation with cost reductions. This is a huge challenge which we cannot
run away from.
34
OPINION
Meio Ambiente e Inovação em PCHs
Environment and SHP Innovation
Por Decio Michellis Jr
Translation Adriana Candal
Innovation and competitiveness regard, not only the economy,
A inovação e a competitividade são não só
de ordem econômica, mas também socioam-
but
biental. Exige cada vez mais tecnologia, diver-
environmental impacts of SHPs increasingly need technology, tech-
sidade tecnológica e aumento da capacidade
nology diversity, and a better capacity of observation.
de observação e aprendizado sobre impactos
socioambientais das PCH´s.
also
the
society
and
the
environment.The
social-
Innovation is the key for the challenge to meet the future
needs of sustainable electric power and low emissions of green-
A inovação é a chave para o desafio de
house gases with the mitigation, compensation measures and the
atender as necessidades futuras de energia
appropriate indemnification regarding the location of the new
elétrica sustentável e de baixas emissões de
SHPs. Three are the main socio-environmental innovation areas re-
gases de efeito estufa com as medidas de miti-
garding SHPs.
gação, compensação e indenização apropriadas ao porte e localização
I – Eco-design: it considers all the possible and economically
das novas PCH´s. São três a principais frentes de inovação socioambi-
feasible techniques that can be used for reducing the social-
ental em PCH´s:
environmental impacts of the SHPs. It is a continuous application
I – Ecodesign: considerar todas as possibilidades técnicas e econo-
of an integrated and preventive socio-environmental strategy, aim-
micamente viáveis de reduzir os impactos socioambientais da PCH. É a
ing at rising the efficiency and reducing the risks to human beings
aplicação contínua de uma estratégia socioambiental integrada e pre-
and to the environment: the best possible (efficaciousness), at the
ventiva, com a finalidade de aumentar a eficiência e reduzir riscos aos
first time, at the lowest cost (efficiency), respecting the environ-
seres humanos e ao meio ambiente: fazer o melhor possível (eficácia),
ment and the people. This includes: prevention (doing more with
na primeira vez, pelo menor custo (eficiência), respeitando o meio am-
less); operability guarantee; ACV (Life Cycle Assessment of the
biente e as pessoas. Isto inclui: prevenção (fazer mais com menos); ga-
Product – from cradle to grave); managing the supply chain; and
rantia de funcionalidade; ACV (Avaliação do Ciclo de Vida do Produto –
whenever it is economically feasible and possible, reducing the ef-
do berço ao túmulo); administrar a cadeia de suprimento; e redução
fects of the implementation of the enterprise by choosing a new lo-
na medida do possível e economicamente viável, dos efeitos da im-
cation and/or reducing the area occupied by the installations
plantação do empreendimento pela escolha de nova localização e ou di-
and/or the effects of the enterprises on the soil, air, biota, the popu-
minuindo a área de ocupação das instalações e ou dos efeitos do em-
lation directly affected and the size of the enterprise.
preendimento sobre o solo, o ar, a água, a biota, população diretamente afetada bem como o porte do empreendimento.
II – Climatic Management: i) Do more with less emissions of
greenhouse gases (GEE) – less consumption, cleaner methods for
II – Governança climática: i) fazer mais com menos emissões
the extraction, processing and use of energy, fuel and raw mate-
gases de efeito estufa (GEE) - menor consumo, métodos mais limpos
rial; and ii) sustainable entrepreneurship and partnerships to
de extração, processamento e utilização de energia, combustíveis e
meet the essential needs of society in a low carbon economy, mak-
matérias primas; e ii) empreendedorismo sustentável e parcerias para
ing good use of all the opportunities that the regulating public poli-
atender as necessidades essenciais da sociedade em uma economia de
cies can offer aiming at cost reduction and lowering prices: incen-
baixo carbono aproveitando todas as oportunidades que as políticas pú-
tives for the reduction in the GGE emissions; increasing the dead-
blicas em regulamentação podem oferecer para redução de custos e ba-
line to renew the environmental licenses; prioritization and lower
ixar preços: fomento para reduções de emissões de GEE; ampliação do
interest taxes in public funding; fiscal incentives; permission mar-
prazo de renovação de licenças ambientais; priorização e menores ta-
kets; non-operational revenues of carbon credits; new energy and
xas de juros em financiamentos públicos; incentivos fiscais; mercado
fiscal policies for energy conservation and the rise in the participa-
de permissões; receitas não-operacionais de créditos de carbono; no-
tion of renewable sources in the energy matrix.
vas políticas energéticas e fiscais para a conservação de energia e o aumento da participação das fontes renováveis na matriz energética.
III – Environmental Flows: for parts with reduced flows or in
the operation of daily-regulated reservoirs, it is necessary to con-
III - Vazões Ambientais: Para trechos de vazão reduzida ou mesmo
sider the environmental variables as operational restrictions (min-
na operação de pequenos reservatórios de regularização diária, consi-
imum residual flow, operational minimum quote, etc.) adopting a
derar as condicionantes ambientais como restrições operacionais (va-
prescribed hydrograph based on the negotiation of an adaptive
zões mínimas defluentes, cota mínima operacional, etc.) adotando um
management for the reduction in the impacts on the complex rela-
hidrograma prescrito baseado na negociação de um manejo adaptati-
tion between the hydrological regimes and the dynamic of the asso-
vo na redução de impactos na complexa relação entre os regimes hi-
ciation of ecosystems.
drológicos e dinâmica de funcionamento dos ecossistemas associados.
Sustainability through innovation is a way of carrying out deals
A sustentabilidade através da inovação é uma maneira de fazer ne-
that allow the rise in competitiveness and creates value for the
gócios que permite o aumento da competitividade e cria valor para os
shareholders in a long term perspective through the use of oppor-
acionistas em uma perspectiva de longo prazo, através do aproveita-
tunities and the management of the risks that come from the de-
mento das oportunidades e do gerenciamento dos riscos derivados de
velopment in the economic and socio-environmental areas, look-
desenvolvimentos nas dimensões econômicas e socioambientais na
ing for the best way to live and live together here and now.
busca da melhor maneira de viver e conviver, aqui e agora.
35
OPINIÃO
O Cenário geral de Crescimento Previsto
para as PCH no Brasil de acordo com Plano Decenal 2010-2019
Por Camila Galhardo, Geraldo L Tiago Filho e Regina Mambeli
O Brasil está em uma situação diferenciada com relação às reservas de fontes renováveis de energia, visto a abundância de fon-
Tabela (1) Evolução da Capacidade Instalada – Plano Decenal 2010-2019
Chart (1) installed capacity's evolution – Decennial Plan 2010-2019
tes de energias alternativas. No momento o país se apresenta como
um dos principais atores globais no que refere à programas e projetos de energias limpas com a produção do álcool combustível, biodiesel, e de sua matriz de energia elétrica baseada na geração hidrelétrica. Enquanto no mundo a participação das energias renováveis
não ultrapassa a 14%, no Brasil a sua participação chega à 46%,
com tendência de crescimento, haja visto a entrada em operação
dos projetos do Proinfa e novos empreendimentos hidrelétricos na
região Amazônica.
Neste contexto as PCHs representam um papel relevante, tendo
em seu passado o rótulo de pioneira na eletrificação do território brasileiro. E após um longo período de investimento em políticas para
grandes unidades geradoras voltam a protagonizar uma expansão
no parque gerador. Expansão que vem extrapolando as fronteiras
geográficas e avançando para regiões de menor concentração populacional como mostrado na figura a seguir.
Figura (2) Evolução da geração, conforme previsto no PDE 2010-2019
Picture (2) Generation's evolution according to
Decennial Plan 2010-2019's prediction
ficativa frente ao atual ritmo de implantação de novas PCHs.
De acordo com o planejado no Plano Decenal (PDE) 2010-2019,
o crescimento da participação das PCHs na matriz elétrica nacional
passará dos atuais 3,9% para 4,17%.
Figura1. Tendência do crescimento de implantação das PCH no Brasil
Hydroelectric power plants' implantation growing tendency in Brazil.
Entretanto, apesar do otimismo do PDE quanto à participação
das PCHs falta um planejamento de longo prazo. Segundo estudos
realizados pelo CERPCH, Tiago Filho e Mambeli (2009) acerca da pro-
Em 2008 havia, no país, 310 plantas em operação que corres-
jeção da evolução da capacidade instalada de energia considerando
pondiam a uma capacidade instalada de 2,209 MW e 77 plantas em
a influência do crescimento do Produto Interno Bruto (PIB) é possí-
construção, que acrescentariam mais 1.264 MW na matriz energéti-
vel demonstrar a diminuição da atratividade econômica dos empre-
ca nacional. Ao final de 2009 o crescimento chegou a 15% com 358
endimentos à medida que os bons empreendimentos vão se escas-
plantas, correspondendo a 3.018 MW de capacidade instalada. E em
seando.
construção havia 73 novas plantas que correspondiam a 998 MW.
De acordo com o Plano Decenal 2010-2019, nos próximos 10
De acordo com a curva vermelha apresentada na Figura (3), página ao lado, o PDE prevê um crescimento para as PCHs acima da ta-
anos está previsto um crescimento na participação das energias re-
xa de crescimento do PIB, desconsiderando o aumento do grau de di-
nováveis na geração de energia elétrica no país e, em contraparti-
ficuldade técnica e a diminuição da atratividade dos novos empre-
da, uma estagnação e até mesmo a redução da participação das fon-
endimentos que são função das condições de mercado no curto pra-
tes fósseis. Conforme mostra o gráfico da Figura (2), A EPE sinaliza
zo, tanto do regulado como do livre, e do interesse dos investidores.
a expansão da geração no país deverá se dar fundamentalmente pela contratação de fontes renováveis de energia já a partir 2013.
Uma forma de reverter o quadro é planejar o crescimento das
PCHs e para tanto é necessário estudos sobre a localização dos po-
Para as PCHs prevê-se, conforme mostrado na Tabela (1), um
tenciais hidráulicos remanescentes suas características técnicas pa-
crescimento dos atuais 4010 MW para 6996 MW em 2019, o que re-
ra adaptação da tecnologia, além da desmistificação do processo de
presenta uma taxa de crescimento de 300 MW/ano. Bastante signi-
licenciamento ambiental de forma a garantir as previsões do plano.
36
OPINION
General growing scene prevision for the hydroelectric power plants
in Brazil according to the Decennial Plan 2010-2019
Translation Greicy Rodrigues de Lima
Brazil is in a different situation when it comes to the renewable
However, despite of Decennial Plan optimism about SHP partici-
energy sources reserves, thanks to its large amount of alternative
pation, still there is a lack for a long term planning. According to
energy sources. At this moment, the country presents itself as one
studies from CERPCH, Tiago Filho e Mambelli (2009) about the en-
of the main global actors in programs and projects of clean energy
ergy's installed capacity evolution's projection, and the the influ-
with the production of ethanol, biodiesel and its energy matrix
ence of the Gross Domestic Product – (GDP) it's possible to demon-
based on hydroelectric generation. While in the world the participa-
strate the decrease of the enterprises' economic attractiveness
tion of renewable energy doesn't exceed 14%, in Brazil it reaches
while good undertakings are getting rare.
46%, tending to increase, due to the beginning of projects from
Proinfa and new hydroelectric undertakings in the Amazon region.
In this context the Small Hydropower Plants play a relevant role,
According to the red curve presented in Picture (3), the decennial plan foresees an increase for the SHP above the growing rate of
the GPD, not taking into account the raise in technical difficulties
having in its past the label of pioneer in electricity in the Brazilian ter-
and the attractiveness decrease on new enterprises which are func-
ritory. And after a long investiture time in big generator unit's policy,
tion of the market in short terms, both regulated and free, and the in-
they restart playing the most prominent part in an expansion of the
vestor's interests.
generator park. As shown in the Picture1.
One possibility for reverting this situation is planning the growth
In 2008 there were, in the country, 310 plants in operation
of SHP, that makes mandatory studies for the localization of the re-
which corresponded to a 2,209 MW installed capacity and 77 plants
maining hydro potential its technical characteristics to adapt the
under construction, which would add 1.264 MW in the national en-
technology, furthermore the demystification of the Environmental li-
ergy matrix. By the end of 2009, it raised 15%, reaching the
censing process in order to accomplish the PDE prediction.
amount of 358 plants, corresponding to 3.018 MW of installed capacity. There were 73 plants in building process which corresponded
to 998 MW.
According to the Decennial Plan 2010-2019, in the next 10 years
an increase in the participation of renewable energy in electrical energy generation is expected in the country and, counterpart, a stagnancy and even a reduction of the fossil sources participation.
As it shows in the graphic in Picture (2), the EPE demonstrates
the generations' expansion in the country which must happen essentially because of the renewable energy sources contracted by
2013.
For the SHP, it's foreseen, according to Chart (1), an increase of
the current 4010 MW to 6996 MW in 2019, which represents a 300
MW/year increasing rate. That is an extremely expressive fact if
compared to the present implantation rhythm .
According to the Decennial Plan 2010-2019, the SHP participation growth in the energy matrix will go from the current 3,9% to
4,17%.
Figura 3: Correlação entre a Capacidade Instalada com base em
PIB (PPIB) e a correção efetuada com base nas curvas com
taxa decrescente de crescimento
Picture (3): Correlation between the Installed Capacity based on the
GDP and the correction made based on the curves
with decreasing growing rate.
37
01 e 02 de Setembro de 2010
Centro de Convenções do Novotel Center Norte
Av. Zaki Narchi, nº 500 - São Paulo - SP
EXPOPCH 2010
Exposição de Equipamentos, Tecnologias e Serviços para Projeto,
Implantação e Operação de PCHs.
Participe e envie seu trabalho.
www.conferenciadepch.com.br
Contato: CERPCH: (35) 3629-1443
(35) 3629-1439
E-mail: [email protected]
A) Análise Financeira
B) Aspectos Legais e Institucionais
C) Mercado e Planejamento Energético
D) Meio Ambiente, Responsabilidade Social e Desenvolvimento Sustentável
E) Tecnologia e Desenvolvimento:
a. Componentes Hidromecânicos
b. Componentes Elétricos Mecânicos
c. Estruturas Hidráulicas
d. Sistemas de Controle
e. Subestação e Transmissão
f. Levantamento de Dados de Campo
g. Geotecnia e Geologia
h. Monitoramento
F) Operação e Manutenção
G) Sistemas Híbridos
H) Geração Descentralizada e Sistemas isolados
EXPOPCH - Exposição de Equipamentos, Tecnologias e Serviços para Projeto, Implantação e Operação
de Pequenas Centrais Hidrelétricas, que consolida o Salão de Negócios existente nas edições
anteriores;
RODADA DE NEGÓCIOS EM PCH - Espaço durante o evento para realização de reuniões previamente
agendadas entre os inscritos;
PRÊMIO PCH – Apresentação e entrega dos melhores trabalhos técnicos.
Realização
38
Organização
CARTA DO LEITOR/READER’S LETTER
Esse espaço é o canal entre os leitores da revista PCH Notícias & SHP News e o CERPCH, nele nossos leitores poderão enviar suas
dúvidas, questionamentos e sugestões. Escreva para [email protected]
Nome:Francienne Gois Oliveira
Name: Francienne Gois Oliveira
E-mail: [email protected]
E-mail: [email protected]
Mensagem: Gostaria de saber qual o procedimento para reati-
Message: I would like to what is the procedure to reactivate a Mi-
var uma microcentral construída em 1947 que se encontra desati-
cro Hydropower Plant built in 1947, which has not been operating
vada a mais de 20 anos. Obrigada pela atenção!
for over 20 years. Regards.
Em se tratando realmente de uma microcentral, ou seja, com po-
If it is really the case of a Micro Hydropower Plant, i.e., with a
tência menor que 1.000 kW, do ponto de vista da Aneel basta que se-
power lower than 1,000 kW, it is enough to make a communication,
ja feita uma comunicação. Vale ressaltar que esta comunicação é fa-
according to Aneel. It is important to highlight that this communica-
cultativa, não havendo portanto obrigatoriedade de fazê-la. Já do
tion is not mandatory, hence there is no obligation to do it. In rela-
ponto de vista dos órgãos ambientais o procedimento é o mesmo da-
tion to environmental organs the procedures are the same as those
quele de uma PCH, ou seja, é preciso elaborar o Relatório de Contro-
used for SHPs, i.e., it is necessary to elaborate an Environmental
le Ambiental (RCA) e o Plano de Controle Ambiental, cuja complexi-
Control Report (RCA) and an Environmental Control Plan, whose
dade será função dos impactos previstos no RCA.
complexity will be based on the impacts forecast in the RCA.
Estes são documentos obrigatórios para que se possa dar entra-
These are mandatory documents to start the licensing process,
da no processo de licenciamento, que inclui a Licença Prévia, a par-
which includes the Previous License, when the executive project can
tir da qual normalmente se inicia o projeto executivo, a Licença de
usually be started, the Installation License, when the construction is
Instalação, a partir da qual se inicia a construção, e, finalmente, a li-
initiated, and finally the Operation License, which allows the plant to
cença de operação que permite a entrada em operação da central.
operate.
Do ponto de vista de custos a opção de reativação é quase sem-
As far as costs are concerned, refurbishing is always more at-
pre mais atrativa do que uma construção a partir do zero, principal-
tractive than building a plant from the ground, if the civil works,
mente se puderem ser aproveitadas obras civis como barragem e ca-
such as the dam, and the powerhouse can be used.
sa de máquinas.
Eng. Ângelo Stano Júnior - CERPCH
Engeneer Ângelo Stano Júnior - CERPCH
CARTA DO LEITOR/READER’S LETTER
This segment is the channel between the readers of the magazine PCH Notícias & SHP News and the CERPCH, where you can send your
doubts, questions and suggestions to. E-mail to [email protected]
Nome: Protasio Alves Martins
Name: Protasio Alves Martins
Fazenda Bem Posta- zona rural – Luna - ES
Fazenda Bem Posta – Luna - ES
E-mail: [email protected]
E-mail: [email protected]
Mensagem: Prezados amigos do CERPCH, gostaria de agradecer
a vocês por terem divulgado o projeto do Carneiro Hidráulico que está sendo muito utilizado por mim.
Meu pai instalou há muitos anos um carneiro antigo de ferro, antes mesmo de eu nascer, hoje tenho 29 nos. Mas, com o passar do
tempo foi ficando difícil de encontrar peças de reposição.
Message: Dear friends from CERPCH. I would like to thank you
for disseminating the Ariat Pump that I have been using constantly.
Many years ago, before I was born, my father installed an old
iron-made ariat pump. Today, I am 29. However, as time goes by, it
became harder and harder to find replacement parts.
I carried out an Internet search and it led me to you. It was the
Eu pesquisei na internet se conseguiria comprar outro carneiro e
best project I have ever seen, not that the other projects do not de-
pela pesquisa consegui chegar a vocês onde foi o melhor projeto
serve my compliments. I assembled the second Ariat Pump of the
que vi, não desmerecendo os outros. Montei o carneiro nº2 da tabe-
CERPCH's table, but I had some difficulties with the hammer valve,
la do CERPCH, tive dificuldades com a válvula do martelo e com a
with the spring and with the use of the PET bottle cap. I was able to
mola e com o tal do furo na tampa da garrafa, mas consegui substi-
replace the cap for a 15mm plastic connection that fits perfectly on
tuir por uma outra confecção de água quente de 15 mm que e perfe-
the PET bottle and I fixed them together using superglue. As the con-
ita para entrar dentro da boca do litro que e fixado com cola aralditi
nection is screwable ( has threads) I only needed to screw it on the
e enroscar no (t).Eu resolvi inventar um pouco e montei um outro
TEE (Part of the Ariat Pump design). I decided to invent a bit and I as-
carneiro e coloquei na frente do primeiro carneiro e agora tenho do-
sembled another pump that was placed ahead of the first one, using
is carneiros trabalhando no mesmo cano em conjunto e desperdi-
the piping of the old one and reducing the loss of water. The second
çando água de um ,o local para a batida do martelo eu coloquei um
pump assures a gain of height of at least 10 meters.
cano de no mínimo 50cm comprimento e um joelhos e a válvula vira-
I congratulate all of those who put this project on the internet.
da para cima sem o parafuso e a mola .Eu aproveitei o encanamento
This idea allowed me to save a significant amount of money, given
antigo e está jogando um cano de meia cheio a uma altura de no mí-
that I could stop using the electrical pump. I will try to send some pic-
nimo 10 metros .
tures so you can see what I did.
Eu parabenizo a todos que se esforçaram para colocar este pro-
Thank you.
jeto na internet e ter podido me beneficiar com ele e ainda poder economizar de não ter que ligar uma bomba elétrica que desde o dia
que o carneiro passou a funcionar não tive que ligar mais a bomba,
quero ver se consigo uma máquina para tirar uma foto e mandar para vocês verem.Muito obrigado!
41
CURSO DE ESPECIALIZAÇÃO EM
PEQUENAS CENTRAIS HIDRELÉTRICAS
Este curso é voltado para a capacitação profissional na área de gestão e
projetos de pequenas centrais hidrelétricas (PCH). Direcionado para
engenheiros, administradores, advogados, economistas e todos os
profissionais correlacionados com a área de PCH, o curso destaca-se como
um diferencial exigido pelo mercado profissional.
GARANTA JÁ A SUA PARTICIPAÇÃO
PREVISÃO DE INÍCIO PARA SETEMBRO DE 2010
ANTECIPE-SE E GARANTA SUA VAGA.
FAÇA HOJE MESMO SUA PRÉ-INSCRIÇÃO PELO SITE.
PÚBLICO ALVO:
ENGENHEIROS
ECONOMISTAS
ADMINISTRADORES
GERENTES
ADVOGADOS
INVESTIDORES
EMPRESÁRIOS
PROFISSIONAIS DO SETOR
Dividido em 10 módulos presenciais, este curso visa o ensino de procedimentos para a viabilidade técnica e econômica, dimensionamento e especificação de componentes
hidromecânicos e elétricos, elaboração de projeto básico,
aspectos regulatórios e ambientais.
O curso pode ser integralizado em um período máximo de
24 meses. Com a conclusão de 9 módulos teóricos e a defesa do trabalho de conclusão de curso, o aluno será avaliado
por uma banca para receber o título de especialista. É permitido cursar os módulos individuais, dando direito a certificação técnica.
Local: Itajubá-MG
Aulas concentradas em uma semana por mês
10 módulos presenciais
Traslado Gratuito: Rio/Itajubá e São Paulo/Itajubá
Integralização: mínimo de 10 e máximo de 24 meses
INVESTIMENTO:
R$ 1.800,00
R$ 16.000,00
por módulo
à vista
Apoio
Realização
Para mais informações, acesse: www.cerpch.org.br/cepch
42