Workpackage 3: Thermal System

1. NTB INTERSTAATLICHE HOCHSCHULE FÜR TECHNIK BUCHS Project Meeting, May 11, 2006 Workpackage 3: Thermal System NMW P. Müller, A. Bolleter, M. Roos, A. Bernard

2. Outline ▪ Overview Work Package and Concept ▪ ThermalDemonstrator and measured Temperature Distribution ▪ Comparison with Simulation ▪ Modified Concept ▪ New Power Ranges ▪ Next Steps and Summary

3. Overview Workpackage 3 NTB INTERSTAATLICHE HOCHSCHULE FÜR TECHNIK BUCHS NMW Thermal System concept, fabrication & measurement concept, simulation Air Heat exchanger Fuel Post combustion Reformer Cathode Electrolyte Anode design, fabrication design, simulation, measurement design, fabrication

4. WP 3: Year 1 Milestones • performance 200 mW/cm2 @ 550°C • external electrical connections Fuel Cell • butane conversion rate > 90% • post-combustor with gas oxidation > 98% Gas Processing • thermal insulation concept with • Tinside 550°C, Toutside 50°C, <10 cm3 • structures for validation critical points • thermal system demonstrator with • simulated 2 W heat source Thermal System Project Management • battery expert • industrial partner

5. Main Achievements Simulation validated with Thermal Demonstrator.

6. Overview Concept and Simulation Stack Heat Exchanger Insulation Insulation Stack Heat Exchanger Stack Radius [mm] Stack temperature [°C] Thickness of Stack [mm] Thickness heat exchanger (Mica) [mm] Heat Flow Distribution

7. Demonstrator with Resistance Heat Source Foturan Dummy-Stack Insulation Element Contact Heater MICA

8. Measured Temperature distribution Insulation thickness: Microtherm 6 mm Constant Heating Power: 2 W 350°C 40°C  7 min for constant temperature  Stack temperature 350 °C and 40°C in surrounding area

9. Temperatures with different Insulations 295 40 30 Aerogel 10 mm, Mica 70 µm 369 43 23 Microtherm 21 mm, Mica 50 µm 349 38 35 Microtherm 6 mm , Mica 50 µm Constant Heating Power: 2 W [°C] • Thicker insulation does not change the stack temperature • With transparent Aerogel lower stack temperature

10. Simulation of Demonstrator:Temperature Distribution 1 Microtherm thickness 6 mm with radiation and MICA 0.5 W/mK Microtherm thickness 6 mm no radiation and MICA 0.5 W/mK 750 °C 395 °C 40°C 40°C

11. Simulation of Demonstrator:Temperature Distribution 2 Microtherm thickness 6 mm with radiation and MICA 0.5 W/mK Microtherm thickness 6 mm with radiation and MICA 4 W/mK 395 °C 364 °C 40°C 40°C

12. Comparing Demonstrator with Concept Thermal Concept µSOFC Demonstrator • Difference of demonstrator to thermal concept • - Channel height • - Radiation in concept along channel not considered • - Gas flow in the channels (Manufacturing) • Conclusion • Measurement correlates with simulation (demonstrator) • Thermal conductivity of mica has influence on stack temperature • Radiation along channel has strong influence on stack temperature •  Modification of concept needed

13. Modification of Concept MICA Heat Exchanger Air • Advantages: • Fabrication, mica no bonding needed • Reduced thermal strain • Reduced thermal radiation • Disadvantages: • Heat exchanger performance lower • Pressure drop higher Stack Fuel Supply Temperature Distribution 550°C 220°C 40°C  First result, research going on

14. New Power-Range • Basic Scaling Properties (first design approach) • Stack structure is modular • Stacking of units is “Milli”-scopic (=conventional technology) • Thermal System not scalable: Adaptation of concept necessary • Thermal Management comparably simpler (surface to power ratio) • Main Issues to be solved • Adapted concepts of insulation for each power range • Fabrication: concept of “modular” system (planar technology) • Layout and Manufacturing of gas and air channels, electric connection

15. Validation of Milestones and Deliverables • WP 3.1 Thermal System Design • Month 3: thermal insulation concept (Tinside = 550°C, Toutside = 50°C) (ZHW) • Month 12: system integration concept incl. thermal management concept heat exchanger design compatible with GPU designs and micro-fabrication (ZHW)   Specification to be revised • Deliverables: • Month 3:design from ZHW  NTB for fabrication  • WP 3.2 Fabrication Concept of Thermal System • Month 6: test structures for validation of critical points of the concept (T diff. 500°C) (NTB) • Month 12: thermal system design demonstrator with simulated heat sources (dummy stack, reformer, post-combustor) (NTB)   Specification to be revised • Deliverables: • Month 6:first samples of GPU from NTB  LTNT for testing 

16. Summary ▪ Thermal Demonstrator shows 350 °C with 2 W ▪ Consistent between Simulation and Measurement ▪ Modification and Adaptation of Thermal Concept ▪ First Approach for New Power Ranges ▪ Revision of Specification needed (Reformer) ▪ Initiation of new Work Package System Development

17. Next steps (Year 2) NMW NTB Thermal Management WP 3.1 • Proof of modified Concept • Concept adaptation to new power range • Integration of reformer and PC into hot module WP 3.2 • Validation of adapted concept System Development WP 4.1 • System Concept development WP 4.2 • Concept First order packaging • Concept Second order packaging

18. Next steps (Year 3 / 4) NMW NTB Thermal Management WP 3.1 • Transient simulation of thermal system • Analyze system design for thermal stress • Increase the level of detail in the thermal mode System Development WP 4.1 • System Control definition • System Design development WP 4.2 • Manufacturing strategy development • Build up a System Demonstrator

19. Questions ? Simulation validated with Thermal Demonstrator.