High Temperature Heat Storage for Process Heat and Power Plants

Transcrição

High Temperature Heat Storage
for Process Heat and Power Plants
Rainer Tamme
DLR - German Aerospace Center
Institute of Technical Thermodynamics – Stuttgart/Köln/Almeria
EUROSOLAR– WCRE “First International Renewable Energy Storage Conference” - IRES I
October 30-31, 2006, Gelsenkirchen, Germany
Folie 1 >
Introduction
Definition of “High Temperature”
• Temperature beyond heating and cooling
> 120 °C
• Water (non-pressurized) NOT applicable as storage material
Available storage technology for HT applications
• Storage of sensible heat in fluids and solid materials
• Latent heat storage – PCM storage
Available heat transfer media for HT applications
• Single phase fluids – different fluids and gases
• two-phase fluids – water/steam
Folie 2 > High Temperature Heat Storage for CSP – IRES I, Gelsenkirchen,
Tamme
Folie 2 >2006>
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> Autor
Dokumentname > 23.11.2004
Rationale - Heat Storage for Process Heat
Effi
cien
cy i
mp
rov
eme
nt
rom CHP
f
n
o
i
t
u
b
d contri
e
s
a
e
r
c
in
Pattern of energy consumption in Germany
+ RES
Future heat generation in Germany
BMU Studie „Ökologisch optimierter Ausbau der Nutzung erneuerbarer Energien in Deutschland“ DLR, ifeu, WI 2004
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Pattern of process heat
temperature range 100 – 400 °C
water/steam as relevant HTF
Examples
• Food processing
• Manufacturing of construction materials
• production of paper, textile industry etc.
• Water purification, desalination
• double effect sorption cooling
temperature beyond 500 °C
flue gas and air as relevant HTF
Examples
• metallurgy
• ferrous and non-ferrous metal casting
• ceramics manufacturing
• glass manufacturing
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Rationale - Heat Storage for Power Generation
incr
eas
ing
RES
increased CSP plants
Future power generation in Germany
Future power generation in MENA countries
BMU Studie „Ökologisch optimierter Ausbau der Nutzung erneuerbarer Energien in Deutschland“ DLR, ifeu, WI 2004
BMU MEDCSP study „Potential and economy of renewable energies in Middle East North African Countries, DLR, 2004
Tamme
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Heat Storage for Power Generation
Examples
Heat storage for solar thermal
power plants
Adiabatic compressed air energy
storage power plant
Decentralized CHP systems
Tamme
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Conclusions for designing TES
Heat Supply
Thermal Energy
Storage
diversified specifications
Heat Utilization
Thermal Energy
Power range from kW to MW
Short term storage – minutes to hour
Long term storage – several hours to days
Capacity from few kWh to GWh
Temperature range from 100 to 1000 °C
large number of primary ad secondary heat transfer media:
water/steam, oil, liquid salt, air etc.
ONE SINGLE storage technology cannot not meet the huge
range of design specifications and operation parameters
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Solid media / Concrete Storage
• sensible storage with castable ceramics and concrete
• preferred for single phase HTF till 400/500 °C
• dual medium indirect storage system with regenerative heat transfer
• modular and scalable design from 500 kWh to 1000 MWh
Important applications
• parabolic trough solar thermal power plants
• waste heat storage < 500 °C
• combined heat and power
Tamme
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Solid media / Concrete Storage
Characteristic behavior of dual media solid TES
T_Oil_out, charging
Important issues:
temperature
Ttend,c
Tt1,c
Tt2,d
Tt2,c
• internal heat transfer
• heat conductivity
of solid media
Tt1,d
Ttend,d
T_Oil_in, discharging
length
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Thermal Engineering and Simulation Tools
power and capacity
temperature distribution
Tamme
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Concrete Storage - Current Status
2 year operation of 2 modules
350 kWh castable ceramic
350 kWh concrete
Second generation concrete
400 kWh storage module
developed with
Expected investment cost
~ 25 €/kWh
(large scale, 6 h cycles)
Concrete storage is ready for
scale-up and demonstration
System integration and
operation
strategy is important issue
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PCM Storage - Motivation
4% Überhitzung
3% Überhitzung
12% Überhitzung
33% Vorwärmung
Preference for PCM storage
two-phase flow HTF
mainly water/steam
55% Verdampfung
solid –melting
- liquid
Preheating93%
evaporation
superheating
Verdampfung
industrial
process steam
sensibler
sensibler
sensibel Latentspeicher
Latentsensibel
solid
liquid cycle power generation
heat rankine
Speicher
Speicher
Superheated
sensibler
steam
10bar process steam
T - range 160°C to 200°C
evaporation temperature 179°C
Temperatur
Speicher
Temperatur
Water
sensibler
wet steam
Latentspeicher
Speicher
100 bar Rankine cycle Tmax 400°C
Reheating and feed water pre-heating
spez. Entropie
spez. Entropie
T profile for HTF water/steam
T profile for solid/liquid PCM
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Approaches for Efficient PCM Storage
to solve heat transfer limitations of PCM
Improved storage materials
PCM with superior
thermal conductivity
Improved heat transfer
Increase heat transfer area
PCM composite
Tubular heat exchanger
with externally arranged PCM
Macro-Encapsulation
Isothermal steam accumulators
with PCM
Tubular heat exchanger
with finned tubes
(Sandwich Concept)
Tamme
Folie 13 >2006>
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> Autor
New improved composite PCM´s
Focussing on Nitrate salts and Graphite matrix
1.
400
LiNO3
350
Enthalpy [J/g]
300
250
200
graphite
Low pressure
steam systemsLiNO3-NaNO3
KNO3-LiNO3
NaNO2
Intercalation and exfoliation
NaNO3
150
100
KNO3-NaNO2-NaNO3
KNO3-NaNO3
Expanded
graphite
worm
KNO3
High pressure
50
Commercial
PCM
steam systems
0
composite
materials
100
150
200
250
300
manufactured by Temperature [°C]
350
Compression
Grinding
3.
Ground expanded
graphite
2.
Compressed expanded
graphite plates
Tamme
Folie 14 >2006>
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> Autor
PCM Storage – Current Status
Process steam storage and solar steam generation
• design concept for improved PCM
storage scientifically proven
• new composite PCM with high thermal
conductivity developed
• validated in 10 kWh storage modules
• 100 kW pilot storage under construction
Tamme
Folie 15 >2006>
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> Autor
Compressed air storage technology
for large scale electricity storage
Adiabatic
CAES
Specific investment cost
Source: Electricity Storage Association
Survey on electricity storage technologies
Tamme
Folie 16 >2006>
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> Autor
Adiabatic CAES - Approach
Air Outlet
M
LP
HP
ST
ST
G
Heat Storage
Air Intake
Cavern
Pure storage technology, locally
emission-free
High storage efficiency
M Motor
LP Low Pressure Compressor
HP High Pressure Compressor
ST Steam Turbine
G Generator
Heat storage needed
Demanding advancement of
turbo engines
– compressor and turbine
Tamme
Folie 17 >2006>
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> Autor
Heat Storage Concepts for ACAES
Solid media TES
Cowpertype
Concrete
walls
Cast iron
slabs
Two-tank
configuration
One-tank
thermocline
Direct
Direct
Direct
Direct
Indirect
Indirect
Natural
stone
Checker
brick
Concrete
Cast iron
Nitrate salt +
Mineral oil
Nitrate salt +
Mineral oil
40 m
36 m 35 m
3m 1m
symmetric axis
active cooling
4m
Storage
medium
Rock bed
9m
5m
3m
4m
Concept
Liquid media TES
2m
22 m
Tamme
Folie 18 >2006>
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> Autor
Heat Storage Development for ACAES
Basic design concept defined
•
layout of storage material configuration
•
pressure vessel-containment design
•
isolation
•
Investigation of storage materials
(thermo-physical and thermo-mechanical
properties)
•
•
Charging/discharging behavior
Cost estimation
Tamme
Folie 19 >2006>
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> Autor
Heat Storage for ACAES – Current Status
Basic design concept developed by
wall
air layer
inventory
Further development to verify design, materials and simulation tools to
establish a basis for a 30 MW demonstration plant
structure
Tamme
Folie 20 >2006>
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Conclusions
Energy storage is a key issue
for efficient energy utilization
to reduce fossil fuels consumption and CO2 emissions
and increased heat and power generation with RES
to balance unequal supply und demand profiles
Concrete storage technology is available until 400 °C
for waste heat storage, CHP and solar trough plants
Advanced storage technologies – PCM or ACAES - have large
potential to provide efficient and economic storage for process heat
and power plants
Continuous and even more research and development effort is
needed to bring the new storage approaches to commercial stage
Tamme
Folie 21 >2006>
VortragRainer
> Autor
Thank You
for your attention
Tamme
Folie 22 >2006>
VortragRainer
> Autor

High Temperature Heat Storage for Process Heat and Power Plants

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