rsoc plant Efficient design and operation behavior

Größe: px

Ab Seite anzeigen:

Download "rsoc plant Efficient design and operation behavior"

Anton Wolf
vor 6 Jahren
Abrufe

Mitglied der Helmholtz-Gemeinschaft rsoc plant Efficient design and operation behavior 24.04.

Forschungszentrum Jülich Institute of Energy and Climate Research Electrochemical Process

1 Mitglied der Helmholtz-Gemeinschaft rsoc plant Efficient design and operation behavior , Hannover Messe Ludger Blum, Matthias Frank, Roland Peters, Detlef Stolten Forschungszentrum Jülich Institute of Energy and Climate Research Electrochemical Process Engineering (IEK-3) Institut für Energie- und Klimaforschung Elektrochemische Verfahrenstechnik (IEK-3)

Motivation Electricity producing renewable energy systems time discrepancy Power isn t available at all times. Demand is decoupled from production Solution: Energy storage and reconversion on demand.

2 Motivation Electricity producing renewable energy systems time discrepancy Power isn t available at all times. Demand is decoupled from production Solution: Energy storage and reconversion on demand. reversible Solid Oxide Cell (rsoc) Storage with solid oxide electrolysis (SOEC) Reconversion with solid oxide fuel cells (SOFC) SOFC-Stack Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 1

3 Outline Characteristics of SOC Plant design Efficiencies in SOFC mode / SOEC mode Switching strategy Long-term operation results Summary Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 2

4 Stack-Characteristic (Electrolysis- / Fuel cell- mode) Cell Zellspannung voltage / V /V Case V supplied electric power SOFC Stack F heating Stromdichte / A cm 2 Zelle 1 Zelle 2 Furnace temperature: 750 C / 2.2 slm H 2 / 2.2 slm H 2 O / 5.3 slm air Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 3

5 Flow chart rsoc-plant Hydrogen tank: Pressure Storage Multi-stage compressor Media supply: Waste heat recovery Electrical Evaporator Recirculation: Increases fuel utilization Provide H 2 in SOEC Performance Integrated Module: Data: Power Compact (SOFC) design H 2 High prod. temperature (SOEC) components Storage pressure Parasitic load 50 W* Inverter eff. 94 %* Air Blower eff. 30 %* Re. Blower. eff. 20 %* * =assumed 5 kw 3.3 m³/h (standard) 70 bar H 2 Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 4

6 Influence of off-gas recirculation in SOFC mode 1. System works with hydrogen and steam 2. Produced steam is separated in Condenser 3. Low amount of steam is recycled 4. Low temperature blower can be used System fuel utilization in case of Recirculation : stack fuel utilization : recirculation ratio Performance data = 20% RR = 99 % = % Effect High High cell voltage Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 5

7 Efficiencies in SOFC mode electrical efficiency increases with small At low : cell voltage is positively influenced, no recirculation system- and stack fuel utilization are equal Performance data SOFC = 20% = 0.5 A/cm² RR = 99 % = 750 C = % η =66% Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 6

8 SOFC Mode with 99 % recirculation ratio From the right: + cell voltage increases, because of H 2 rich gas mixture + Air quantity drops by cooling on fuel side - Pressure loss on fuel side increases Maxima Operating Point =20% = 0.5 A/cm² = 750 C =99% Specification =96% = 6035 W =66%, Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 7

9 Efficiencies in SOEC mode Recirculation ratio is designed to provide 10 vol.-% of hydrogen Prevent high degradation Efficiency increases with increasing steam utilization Less energy is needed for evaporation Less recirculation is required with increasing utilization H 2 -amount is a const. volume fraction, Performance data SOEC =80% = 0.6 A/cm² = 750 C = 14% Specifications = 73.5 % = 3.3 Nm³/h = 70 bar spec. Energy = 4.08 kwh/nm³ Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 8

10 Strategy for changing the operation mode SOFC SOEC States: 0. Initial mode 1. Adjust the composition of fluids to changeover composition 2. Adjust current 3. Adjust the composition of fluids Time [min] j [A/cm²] nh2 100% 50% 50% 20% nh2o 0% 50% 50% 80% Conv. 70% 70% 70% 70% Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 9

11 Simulation results: Switching from SOFC to SOEC Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 10

12 Simulation results: Switching from SOFC to SOEC Δ=18 K Temperature fluctuations are negligible Slight fluctuations after switching (Investigation if control technology can be improved) Switching is no problem Cell voltage is almost stable (after switching procedure) Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 11

13 SOFC stack- long term constant current operation 700 C, FU: 40%, H 2 O: 20% SOFC WORLD RECORD operation under load > h Mean degradation: 0.6 %/kh Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 12

rsoc stack long term electrolysis test Fuel-/steam-utilization: 50% SOEC WORLD RECORD operation under load > 18

14 rsoc stack long term electrolysis test Fuel-/steam-utilization: 50% SOEC WORLD RECORD operation under load > h Mean degradation: 0.7 %/kh Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 13

15 Summary rsoc-plant concept developed and under construction Off-gas recirculation with condensation Waste heat recovery in an economizer Switching strategy was dynamically simulated Switching time < 5 min Temperature fluctuations are negligible Operating points j [A/cm²] T [ C] [%] [%] SOFC SOEC Round trip efficiency 66 % 73.5 %. % (including compression to 70 bar; no external heat) 66 % 79.9 %. % (without compression to 70 bar; no external heat) Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 14

16 Thank you for your attention Institut für Energie- und Klimaforschung IEK-3: Elektrochemische Verfahrenstechnik 15

Ähnliche Dokumente

Simulation of a Battery Electric Vehicle

Simulation of a Battery Electric Vehicle M. Auer, T. Kuthada, N. Widdecke, J. Wiedemann IVK/FKFS University of Stuttgart 1 2.1.214 Markus Auer Agenda Motivation Thermal Management for BEV Simulation Model