Workpackage 3: Thermal System

1
Workpackage 3 Thermal System
Project Meeting, May 11, 2006
NMW
P. Müller, A. Bolleter, M. Roos, A. Bernard
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
3
Overview Workpackage 3
Thermal System
concept, fabrication measurement
concept, simulation
Air
Heat exchanger
Fuel
Post combustion
Reformer
Cathode Electrolyte Anode
design, simulation, measurement
design, fabrication
design, fabrication
4
WP 3 Year 1 Milestones

• performance 200 mW/cm2 _at_ 550C
• external electrical connections

Fuel Cell

• butane conversion rate gt 90
• post-combustor with gas oxidation gt 98

Gas Processing

• thermal insulation concept with
• Tinside 550C, Toutside 50C, lt10 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 Radius mm
Stack temperature C
Thickness of Stack mm
Thickness heat exchanger (Mica) mm
Distribution
Heat Flow
7
Demonstrator with Resistance Heat Source
8
Measured Temperature distribution
Insulation thickness Microtherm 6 mm Constant
Heating Power 2 W
350C
40C
? 7 min for constant temperature ? Stack
temperature 350 C and 40C in surrounding area
9
Temperatures with different Insulations
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
40C
40C
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
40C
40C
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
550C
220C
40C
? 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
  550C, Toutside 50C) (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. 500C)
  (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)
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)
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.
20
Thermal Conductivity Mica
Measurement Setup
? (?Reference AReference lr (T3-T1))/(lm
ASample (T6-T4))
Measurement Result Modification of Setup needed
(Reference material)
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) Biotite 1.17 W/mK (Landolt-Börnstein,
Physikalische Eigenschaften der
Gesteine) Chlorite 5.14 W/mK (Landolt-Börnstein,
Physikalische Eigenschaften der
Gesteine) Talc 6.1 W/mK (Landolt-Börnstein,
Physikalische Eigenschaften der Gesteine)
21
Next steps (Year 2)

• 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

• 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

22
Next steps (Year 3 / Year 4)

• 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

• 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

23
Measured Temperature distribution
Aerogel 10 mm, Mica 70 µm
Microtherm 21 mm, Mica 50 µm
Microtherm 6 mm , Mica 50 µm
C
Heating Power 2 W
24
Demonstrator with 2 W
23C
350C
57C
37C
38C
Microtherm 6 mm
285C
35C
36C