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

WP 3: Thermal System Strictly Confidential 2 Outline ▪ Overview Work Package and Concept ▪ Thermal Demonstrator and measured Temperature Distribution ▪ Comparison with Simulation ▪ Modified Concept ▪ New Power Ranges ▪ Next Steps and Summary

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

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

WP 3: Thermal System Strictly Confidential 5 Main Achievements Simulation validated with Thermal Demonstrator.

WP 3: Thermal System Strictly Confidential 6 Overview Concept and Simulation Thickness of Stack [mm] Stack temperature [°C] Stack Heat Exchanger Insulation Stack Heat Exchanger Insulation Thickness heat exchanger (Mica) [mm] Stack Radius [mm] Distribution Heat Flow

WP 3: Thermal System Strictly Confidential 7 Demonstrator with Resistance Heat Source Foturan Dummy-Stack MICA Insulation Element Contact Heater

WP 3: Thermal System Strictly Confidential 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

WP 3: Thermal System Strictly Confidential 9 Temperatures with different Insulations Aerogel 10 mm, Mica 70 µm Microtherm 21 mm, Mica 50 µm Microtherm 6 mm, Mica 50 µm [°C]  Thicker insulation does not change the stack temperature  With transparent Aerogel lower stack temperature Constant Heating Power: 2 W

WP 3: Thermal System Strictly Confidential 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 395 °C 750 °C 40°C

WP 3: Thermal System Strictly Confidential 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 364 °C 395 °C 40°C

WP 3: Thermal System Strictly Confidential 12 Comparing Demonstrator with Concept 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 Demonstrator Thermal Concept µSOFC

WP 3: Thermal System Strictly Confidential 13 Modification of Concept Advantages: - Fabrication, mica no bonding needed - Reduced thermal strain - Reduced thermal radiation Disadvantages: - Heat exchanger performance lower - Pressure drop higher Stack Fuel Supply MICAHeat Exchanger Air Temperature Distribution 550°C 220°C 40°C  First result, research going on

WP 3: Thermal System Strictly Confidential 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

WP 3: Thermal System Strictly Confidential 15 Validation of Milestones and Deliverables  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) WP 3.1 Thermal System Design Month 3: thermal insulation concept (T inside = 550°C, T outside = 50°C) (ZHW) Month 12: system integration concept incl. thermal management concept heat exchanger design compatible with GPU designs and micro-fabrication (ZHW)  Deliverables: Month 3: design from ZHW  NTB for fabrication Deliverables: Month 6: first samples of GPU from NTB  LTNT for testing    Specification to be revised  Specification to be revised

WP 3: Thermal System Strictly Confidential 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

WP 3: Thermal System Strictly Confidential 17 Next steps (Year 2) WP 4.1 System Concept development WP 4.2 Concept First order packaging Concept Second order packaging 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 Thermal Management System Development NMW NTB

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

WP 3: Thermal System Strictly Confidential 19 Questions ? Simulation validated with Thermal Demonstrator.

WP 3: Thermal System Strictly Confidential 20 Thermal Conductivity Mica λ = (λ Reference * A Reference *lr * (T3-T1))/(lm * A Sample *(T6-T4)) Measurement Setup Mica Literature Values Muskovit 0.25 – 0.75 W/mK (Astrel Pfäffikon) 2.32 W/mK (Landolt-Börnstein, Physikalische Eigenschaften der Gesteine) Phlogopit approx. 1.7 W/mK (Astrel Pfäffikon) Biotite1.17 W/mK (Landolt-Börnstein, Physikalische Eigenschaften der Gesteine) Chlorite5.14 W/mK (Landolt-Börnstein, Physikalische Eigenschaften der Gesteine) Talc6.1 W/mK (Landolt-Börnstein, Physikalische Eigenschaften der Gesteine) Measurement Result: Modification of Setup needed (Reference material)

WP 3: Thermal System Strictly Confidential 21 Next steps (Year 2) System Development WP 4.1: System Concept development Combine reformer, pc and fuel cell to a module in the limitation of thermal concept and regard to the new power ranges (Specifications) WP 4.2: First order packaging development Develop concept of bonding-, el. contact-, gas flow-strategies and process, modular (?) for different power ranges based on the system concept development (WP 4.1) WP 4.2: Second order packaging development Merge fuel cell module with insulation and all needed components Thermal Management WP 3.1: Proof of modified Concept Analysis of limitations, validation by measurement of test structure, check influence of radiation WP 3.1: Concept adaptation to new power range Develop insulation strategies for new power range based on the modified concept. Thermal radiation shielding at cell level WP 3.1: Integration of reformer and PC into hot module Constructional constraints for integration reformer and PC into adapted concept. Minimal required volume of reformer (evaluated by LTNT) WP 3.2: Validation of adapted concept Build up a test structure for concept validation of the 2.5 Watt system NMW NTB

WP 3: Thermal System Strictly Confidential 22 Next steps (Year 3 / Year 4) System Development WP 4.1: System Control definition: Startup, shutdown, standby, peak mode, normal mode WP 4.1: System Design development: Knowing design limitation and performance of system, components, packaging a detailed design are developed WP 4.3: Manufacturing strategy development: Development of process flow, decision on technology, batch and or single processing in respect of industrial mass production and target costs Thermal Management WP 3.1: Transient simulation of thermal system: Simulate the different system conditions, such as startup, shutdown, standby e.g. in respect to thermal issues WP 3.1: Analyze system design for thermal stress: Identify thermal stresses, check the mechanical stability of the design, explore mechanical stability in transient phases. WP 3.1: Increase the level of detail in the thermal model: Extend the simulated thermal model to detail issues of the system design NMW NTB

WP 3: Thermal System Strictly Confidential 23 Measured Temperature distribution Aerogel 10 mm, Mica 70 µm Microtherm 21 mm, Mica 50 µm Microtherm 6 mm, Mica 50 µm Heating Power 2 W [°C]

WP 3: Thermal System Strictly Confidential 24 Demonstrator with 2 W Microtherm 6 mm 23°C 350°C 38°C 285°C 35°C 36°C 37°C 57°C