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Status of the Acumentrics SOFC Program
Dr. Norman BessetteSECA Annual Workshop
Boston, MA.May 11, 2004
Copyright 2004 Acumentrics Corporation 2
Acumentrics Corporation • ~ 75 Employees• Manufacturing since 1994•Based in Westwood, Mass.•~40,000 sq. ft facility• Critical disciplines in-house
Electrical EngineeringMechanical Engineering
Chemical EngineeringThermal ModelingCeramics ProcessingManufacturingSales & MarketingAutomationFinanceCourtesy of the NASA & EIT Consortium
Copyright 2004 Acumentrics Corporation 3
d
Industrial-UPS®Commercial
Rugged-UPS®Military
Acumentrics Battery based UPS500Watts - 20kWatts
Uninterruptible Power Supplies for Harsh
Environments
Features:• Sealed electronics• Able to withstand vibration• Unity power factor input• Wide input 80VAC - 265VAC• Isolated 120 / 240VAC output• Hot swap battery case• Parallelable to 20 kWatts
Copyright 2004 Acumentrics Corporation 4
Acumentrics CorporationAlliance Investments
Northeast Utilities
ChevronTexaco
Connecticut Innovations
NiSource
Sumitomo
General Dynamics
Morgan Stanley
Copyright 2004 Acumentrics Corporation 5
How Acumentrics Fuel Cells Work
Copyright 2004 Acumentrics Corporation 6
Q1 Q3 Q1 Q32000 2000 2001 2001
10 Watts25 Watts
200 Watts
700 Watts2000 – 2001Electrolyte supported
Tubular SOFC Systems
Acumentrics Fuel Cell EvolutionAcumentrics Fuel Cell Evolution
Copyright 2003 Acumentrics Corporation
Copyright 2004 Acumentrics Corporation 7
Stack Design Attributes
• Anode support tubes• Brazed seals• Stackable design• Welded electric connections• Low thermal mass• Withstands heat expansion
Acumentrics Fuel Cell EvolutionAcumentrics Fuel Cell EvolutionStackable Manifold design
High Power Anode Tubes
2002 – 2003Anode supportedTubular SOFC Systems
5 WattTubesQ2 2002
20 WattTubes
Q3 2003
Copyright 2004 Acumentrics Corporation 8
Acumentrics Tubular SOFC POX System Overview
Copyright 2004 Acumentrics Corporation 9
Acumentrics Tubular SOFC Steam Reformed System Overview
Copyright 2004 Acumentrics Corporation 10
Operates on line pressure natural gasFuel internally reformed by partial oxidationSystem Efficiency capable of mid 30% range
Acumentrics 2kW UPSAcumentrics 2kW UPSFull on-line UPS
For Cable/Broadband
Copyright 2004 Acumentrics Corporation 11
APU Core Module
• 45 minute start-up• Excellent cycle capability• Excellent load following • Low pressure gas feed• Direct in-cell reforming
Q4 - 2002
Acumentrics Fuel Cell EvolutionAcumentrics Fuel Cell Evolution2002
Anode supportedTubular SOFC Systems
5,000 Watt
Copyright 2003 Acumentrics Corporation
Copyright 2004 Acumentrics Corporation 12
5kW Auxiliary Power Unit
Copyright 2004 Acumentrics Corporation 13
5kW Stationary CHP Unit
SECA Program
Copyright 2004 Acumentrics Corporation 15
Product Objectives
• Culminate in a 10kW modular stack capable of meeting a number of market requirements.
• Widen our fuel choices.• Build upon our knowledge of “ruggedized”
products for harsh environments.• Allow for modular build up to the 100kW class
size.• Allow for integration with military towable power
units in the 5-20kW size.
Copyright 2004 Acumentrics Corporation 16
Cell Production
• Tasks:– Improve Anode Conductivity– Accelerate Tube Firing– Reduce Silver Content
• Accomplishments to date:– Bisque firing capable of reduction from 48 to
12 hours– Silver Content reduced by over 50%
Copyright 2004 Acumentrics Corporation 17
Cell Production ProcessMixing Extrude Tube Dry Tube Cut to Size
Bisque Fire tube Slurry Deposit Electrolyte Sinter Electrolyte
Cathode Deposition Cathode Firing Apply Cathode CC
Finished Cell
Copyright 2004 Acumentrics Corporation 18
Anode Tube Extrusion
Copyright 2004 Acumentrics Corporation 19
Anode Tube Bisque Firing
Copyright 2004 Acumentrics Corporation 20
Electrolyte Deposition
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Cathode Coating Operation
Copyright 2004 Acumentrics Corporation 22
Brazing Apparatus
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Brazing Apparatus operating
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Comparison of poorly brazed and well-brazed Joint
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Low Cost Braze-Life Graph
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Etime, hr
Pote
ntia
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/cm
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Brazing
New Braze Materials have been validated reducing cost from over $1400/kW to less than $1/kW.
New Braze Cap manufacturing process has reduced cost from ~$6/cell to ~$0.50/cell
Copyright 2004 Acumentrics Corporation 27
SECA Cell Testers
Copyright 2004 Acumentrics Corporation 28
Two 7mm diameter cells on lifetest
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0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000Elapsed Time, hr
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Rec
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rnac
e te
mpe
ratu
re, C
120202-01 P3, V 121902-01 2L, VTemperature, C
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Present 15mm History
0.000
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0.700
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0 168 336 504 672 840 1008
Elapsed Time of Test (hours)
Volta
ge (V
olts
)
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Cell Power Trend
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Cell Current, A
Cel
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Electrolyte Supported Cells- Through December 20017mm Anode Supported Tubes - January 2002
15mm (22 cm length) Anode Supported Tubes- Oct 2002
15mm (33 cm length) Anode Supported Tubes- December 2002
15mm (45cm length) Anode Supported Tubes-January 2003
22mm anode supported tube- Projected December 2004
Copyright 2004 Acumentrics Corporation 31
Cell Technology
• Phase I will continue our evolution from 5W –15W/tube to 25W/tube
• Phase II/III will further that work to 50W/tube
• The first 6 mo. of SECA funding has helped us advance 33% toward the first goal.
Copyright 2004 Acumentrics Corporation 32
• Excellent start-up• Excellent cycle capability• Excellent load following • No fuel pumps.• Direct reformation
Anode supportedTubular SOFC Systems
Acumentrics Generator DesignAcumentrics Generator Design
Copyright 2004 Acumentrics Corporation 33
Generator Cost Reductions
• Early SECA work on manifolds has shown the potential for cost reduction from $690/kW to $80/kW with further advancement to
Copyright 2004 Acumentrics Corporation 34
Bended Tube Recuperator
Copyright 2004 Acumentrics Corporation 35
Ceramic Recuperator
Copyright 2004 Acumentrics Corporation 36
Control Electronics Evolution
• Programmable Logic Controllers, PLCs– Size 24” X 15”, $6000 per System
• Printed Circuit Board, PCB, Controller– Size 11” X 7.5”, $400 per System
Copyright 2004 Acumentrics Corporation 37
System Pictures
• PLC System • Control PCB
Copyright 2004 Acumentrics Corporation 38
Control System Wiring
• Discrete wiring harness • 150 through bulkhead connections• Centralized control board• System wiring cost $500
– Limited opportunities for cost reduction• The wiring costs more than the electronics!
Copyright 2004 Acumentrics Corporation 39
Distributed vs. Centralized Control
• Several small intelligent I/O boards.• CAN bus communication.• Eliminates substantial wiring and cost.• Modular, incremental and applicable to a
wide variety of systems.• Redundancy and fault tolerance is easier
and more cost effective to achieve.
Copyright 2004 Acumentrics Corporation 40
Fuel Cell Interface Converter, FC-IC
• Interfaces fuel cell to energy storage system• Controls fuel cell output current• Utilizes efficient automotive MOSFETs• Interleaved buck – boost topology• 6kW building block• 30 - 90 V input, 30 - 60V output, 200 amps
Copyright 2004 Acumentrics Corporation 41
SECA Power Conversion Tasks• Complete design, fabrication and test of a
98% efficient 48VDC power electronics front end.
Copyright 2004 Acumentrics Corporation 42
Low Voltage Inverter Development
• The FC-IC topology can be configured into an inverter.
• An interleaved topology and high frequency MOSFETs greatly reduce output filter requirements and cost.
• Preliminary efficiency measurements are in the 96-97% range.
Copyright 2004 Acumentrics Corporation 43
FC-IC Based Inverter Development Platform
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SECA Inverter EfficiencyFuel Cell Power Inverter Efficiency
80.00%
82.00%
84.00%
86.00%
88.00%
90.00%
92.00%
94.00%
96.00%
98.00%
100.00%
0 2000 4000 6000
Power Output (Watts)
Effic
ienc
y
Overall
Transformer
Inverter
Copyright 2004 Acumentrics Corporation 45
Power System Projections
• Cost will be $100-$150/kW with the appropriate volumes.
• Efficiency will be 92-95%• Device efficiency and packaging advances
in the automotive industry will drive the cost towards the $50/kW goal.
Copyright 2004 Acumentrics Corporation 46
Conclusions• Been in the fuel cell business for 4 years.• Completed over 1 year operation on previous generation
cell technology.• We have shipped 14 alpha & Beta units for field testing.• Demonstrated the ability to operate complete systems on
lie-pressure natural gas and commercial propane.• Developed a scalable low-cost manufacturing process.• Enhanced cell power by 15x in 3 years & are proceeding
toward an additional 2-3x• Developed the hardware & firmware for a low cost
controller.• Prototyped a low cost, high efficiency inverter capable of
achieving SECA cost & efficiency targets.
Copyright 2004 Acumentrics Corporation 47
Acknowledgement
Department of Energy-National Energy Technology Laboratory
Don Collins, Project Manager
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