Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
High Temperature Thermochemical Energy Storage: Operation Modes of a 10kW Pilot Reactor based on
CaO/Ca(OH)2
M. Schmidt, M. Linder, C.Roßkopf, M. Haas, M. Linder, A. Wörner, A. Thess
German Aerospace Center (DLR), Cologne, Germany
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 1
High Temperature Thermochemical Energy StorageApplications
- Decoupling of solar radiation from eletricityproduction
- Flexibility of conventional power plants
- Reutilization of industrial waste heat
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Folie 2
High Temperature Thermochemical Energy StorageLimestone as a promising storage material
- Cheap raw material (70$ per ton)
- Environmental friendly and nontoxic
- Production in industrial scale
- Additional chemical potential with the reaction with water vapor
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 3
Thermochemical Energy StorageReaction System CaO/ Ca(OH)2
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 4
CaO(s) + H2O(g) ⇌ Ca(OH)2(s) + ∆H
charging step - endothermal
0,001
0,01
0,1
1
10
1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7
p gas
[bar
]
Temperatur 1000 / T [1/K]
CaO(s)
Ca(OH)2(s)
636727 560 496 441 394 352 315
Temperature [°C]
H2O(g)
discharging step - exothermal
0,001
0,01
0,1
1
10
1,0 1,1 1,2 1,3 1,4 1,5 1,6 1,7
p gas
[bar
]
Temperatur 1000 / T [1/K]
Thermochemical Energy StorageReaction System CaO/ Ca(OH)2
- Very high energy density – 0,4 kWh/kg- Adjustability of charge and discharge temperature- Possibility to transform heat- Loss free storage of chemical potential
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 5
CaO(s) + H2O(g) ⇌ Ca(OH)2(s) + ∆H
storage Ca(OH)2(s)
CaO(s)
636727 560 496 441 394 352 315
Temperature [°C]
H2O(g)
Material Properties - CaO/Ca(OH)2
Chemical properties:
Thermophysical properties:
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 6
F.Schaube et al. (2012).A thermodynamic and kinetic study of the de- and rehydration of Ca(OH)2 at high H2O partial pressures for thermo-chemical heat storage. Thermochimica Acta 538(2012) 9 - 20
C. Roßkopf et. al (2014) Investigation of Nano Coated CaO Ca(OH)2 Cycled in Thermochemical in a Thermochemical Heat Storage, submitted
Pilot Reactor - 10kW, 25kg Ca(OH)2plate heat exchanger
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 7
HTF HTF
ReactionBed
Heat Flux
Heat Conduction
vReaction Bed
Pilot Reactor - 10kW, 25kg Ca(OH)2plate heat exchanger
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 8
HTF HTF
ReactionBed
Heat Flux
Heat Conduction
vReaction Bed
CaO(s) + H2O(g) ⇌ Ca(OH)2(s) + ∆H
510°C
Charging ModeDehydration of Ca(OH)2 at 100mbar vapor pressure
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 9
0
0,2
0,4
0,6
0,8
1
1,2
400
420
440
460
480
500
520
0 50 100 150 200 250 300 350 400 450
Pres
sure
[bar
]
Tem
pera
ture
[°C
]
Time [min]
T_air_in
T_R_03
T_R_05
T_R_11
T_R_12
T_air_out
p_reactor
Discharging Modehydration of CaO at 1 bar vapor
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 10
300
350
400
450
500
550
0,00 20,00 40,00 60,00 80,00 100,00 120,00 140,00 160,00 180,00
Tem
pera
ture
[°C
]
time [min]
T_air_inlet
T_R_01
T_R_05
T_R_11
T_R_13
Heat Generation ModeHydration of CaO, starting temperature of 350°C
www.DLR.de • Chart 11
0,00
0,10
0,20
0,30
0,40
0,50
0,60
0,70
0,80
0,90
1,00
330
350
370
390
410
430
450
470
490
0,00 50,00 100,00 150,00 200,00 250,00
Con
vers
ion
Tem
pera
ture
[°C
]
time [min]
T_air_inlet
T_air_outlet
Conversion
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
Next StepsSeparation of Power and Capacity
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 12
Pro
cess
inte
grat
ion:
HTF
HTF
Capacity ~ A_hex ~ $$$
Pro
cess
inte
grat
ion:
Capacity
P_reactor ~ $
Next StepsSeparation of Power and Capacity – Pilot Plant in 2015
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 13
Capacity: 100 kWh~ 250 kg Ca(OH)2
Reactor: 10 kW~ 25 kg/h
Summary
- Thermochemical energy storage with CaO/ Ca(OH)2demonstrated in kW scale
- Peak power of 8 kW
- Charging at 450°C
- Discharging at 490°C and 545°C
- Demonstration of moving bed pilot plant scheduled for beginning of 2015
> Grand Renewable Energy 2014 > Matthias Schmidt • Operation Modes of a High Temperature Thermochemical Heat Storage System in kW-Scale > 28th July to 1st Aug 2014
www.DLR.de • Slide 14
German Aerospace Center (DLR), Cologne, GermanyInstitute of Technical ThermodynamicsThermo-chemical Systems