Applications os Steam Turbines Simulation Models in

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APPLICATION OF STEAM TURBINES SIMULATION MODELS IN
POWER GENERATION SYSTEMS
C.S.Bresolin, ABSTRACT
P.S. Schneider, The goal of this work is to simulate partial load operation of steam turbines in
H.A. Vielmo different controlling modes. An isentropic efficiency function is associated to a
specific steam turbine. The Schegliáiev and the Stodola's Ellipse Law, relating
and F.H.R.França levels of pressure with mass flow, are compared. The proposed operational modes
are: a) sliding pressure; b) throttling valve; c) nozzle valve. As a conclusion,
Schegliáiev and Stodola's models leads to very similar results and the operational
modes by valves establishes theoretical limits of operation for steam turbines. The
sliding pressure control is more efficient considering design operation.
Universidade Federal do Rio Grande do Sul
Departamento de Engenharia Mecânica
Rua Sarmento Leite, 425.
Keywords: steam turbines, partial loads, isentropic efficiency, Stodola's Ellipse
Law, nozzle analogy
90050-170 Porto Alegre RS.
[email protected]
[email protected]
[email protected]
[email protected]
m&
W&
1
2
D
i
W&
n
W& = åhi m& i (h1i - h2 si )
(1)
i =1
m& i
Engenharia Térmica (Thermal Engineering), Vol. 5 - Nº 01 - July 2006
73
Ciência/Science
Bresolin et al. Application of Steam Turbines ...
m&
=
m& D
h=
h1 - h2
h1 - h2 s
(P
)
)
2
- P22 - s (P1 - P2 )
T1D
2
2
2
P1D - P2 D - s (P1D - P2 D ) T1
(
2
1
(3)
(2)
k
e
s= *
1- e*
æ 2 ö k +1
e* = ç
÷
è k +1ø
(4)
2
s (P1D - P2 D )
2
s (P1 - P2 )
m&
P
= 1
m& D P1D
T1D
T1
(5)
f
m&
Pv
f=
(6)
æB ö
fi µ 1 - çç i ÷÷
è Pi ø
m&
Engenharia Térmica (Thermal Engineering), Vol. 5 - Nº 01 - July 2006
æB ö
fi
= 1 - çç i ÷÷
fid
è Pi ø
2
2
æB ö
1 - çç iD ÷÷
è PiD ø
(7)
2
(8)
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Ciência/Science
Bresolin et al. Application of Steam Turbines ...
Algebraically rearranging this equation in regard to
P,
Bi
Pi =
(9)
1 - fi2YiD
(
)(
YiD = PiD2 - BiD2 / PiD2 fiD
f
h=
)
(10)
f
W& = h m& [h1 (P1 , T1 )- h2 (P2 , T2 )]
(11)
m& = f (P1 ,T1 )
(12)
h = f (m& )
(13)
h1 (P1 , T1 )- h2 (P2 , T2 )
h1 (P1 , T1 )- h2 s (P2 , s1 )
s1 = f ( P1 , T1 )
(14)
Engenharia Térmica (Thermal Engineering), Vol. 5 - Nº 01 - July 2006
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Engenharia Térmica (Thermal Engineering), Vol. 5 - Nº 01 - July 2006
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