development of a toroidal intersecting vane machine air ...€¦ · machine air management system...
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MECHANOLOGY, LLC 1
Development of a Toroidal Intersecting Vane Machine Air Management System for Automotive
Fuel Cell Systems
Sterling Bailey Ph.D., P.E. Mechanology, LLC
The focus of this program is to develop the innovative TIVM concept into working compressor/expander/motor hardware that satisfies the FreedomCAR Guidelines – and is easily adaptable
to individual car system requirements – and to measure the TIVM air management system performance
MECHANOLOGY, LLC 2
Relevance and Objective of The TIVM Compressor/Expander/Motor Development Project
The Objective of Mechanology’s TIVM CEM Development and Demonstration project is to overcome the following Transportation Systems Technical Barrier identified in the Draft Fuel Cell R&D Plan:
“Compressors/Expanders. Automotive-type compressors/expanders that minimize parasitic power consumption and meet packaging and cost requirements are not available. To validate functionality in laboratory testing, current systems often use off-the-shelf compressors that are not specifically designed for fuel cell applications resulting in systems that are heavy, costly, and inefficient. Automotive-type compressors/expanders that meet the FreedomCAR program technical guidelines need to be engineered and integrated with the fuel cell and fuel processor so that the overall system meets packaging, cost, and performance requirements. “
MECHANOLOGY, LLC 3
The Toroidal Intersecting Vane Machine Concept
MECHANOLOGY, LLC 4
Toroidal Intersecting Vane Machine Characteristics
Positive Displacement
- Compressor/Expander
- Compressor/Compressor
- Blower
High Flow
High or Low Pressure
Small Volume
Low Production Cost
Many Spin-off Products
TIVM Attributes Provide Efficient Operation as an
Integral Compressor/Expander for Automotive Fuel Cell
Applications With Very Good Performance at High Turndown
Ratios
MECHANOLOGY, LLC 5
TIVM Development TimelineSoftware Developed
TIVM Concept Invented at
Stanford
DOE Contract AwardUS and Foreign
Patents Granted TIVM CEM Prototype Due
Generic Prototype Built
DOE Contract Start
Pressure and Flow Demonstrated
Single Vane Test Rig Operational
Fabricate TIVM CEM Prototype, Measure
Mathematics Developed
Friction, Sealing, and Porting Tech Solution
Performance, Deliver
MECHANOLOGY, LLC 6
The Basic Viability of the TIVM Has Been Proven Through Hardware and Tests
Outlet Pressure vs Time, Generic Prototype
0
0.5
1
1.5
2
2.5
3
3.5
4
0 2 4 6 8 10 12
Time, sec.
Pre
ssu
re,
atm
.
DOE
0
0.5
1
1.5
0
20
40
60
80
100
130 140 150 160 170 180 190 200 210
440C Stainless Steel on PEEK 450FC30010806D
Friction Coefficient Linear Velocity (m/s)
Fric
tion
Coe
ffici
ent
Linear Velocity (m/s)
Time (s)
MECHANOLOGY, LLC
MECHANOLOGY, LLC 7
Requirements Compliance Matrix for TIVM Compressor/Expander
Expected to be acceptable
Cost estimates based on vendor quotesGive several $100’s in high volume
$400Cost
To Be Demonstrated
Use of polymer parts and compliant seals will mitigate
<70 dbNoise
16 kg – Acceptable (2005)
Acceptable to car makers and OEMs8-11 kgWeight
8 L – Acceptable(2005)
Acceptable to car makers and OEMs(Compressor, expander, and motor)
8-11 litersSize
6 kW - Remains to be Demonstrated
Key remaining performance issue –requires low friction effective seals
5.0 kWPower
Capability Demonstrated
3.5 atm pressure demonstrated with temporary seals - as expected for positive
displacement device
3.2 atm Pressure
Capability Demonstrated
Flow consistent with design flow demonstrated with temporary seals - as
expected for positive displacement device
76 g/s(135 cfm)
For 50 kWe
Flow
TIVM StatusCommentValueRequirement
MECHANOLOGY, LLC 8
Three Key Performance Issues Needed to Satisfy the Power Requirement
• Seals to limit air leakage without adding excessive friction• Confirmation of coefficient of friction for meshing vane
interface – including high humidity environment• Porting to assure low pressure drop, and power loss, across
the compressor and expander inlet and discharge paths
These are not unusual engineering tasks that require inventions or new materials. Solid, disciplined engineering development
will provide the required solutions
MECHANOLOGY, LLC 9
Requirements for Vane Seals(For 6 kW Shaft Power at 100% Power and Flow)
Limit air leakage from compressor and expander to < 5%
- leakage rate < 0.38 g/s for full power and flow
- leakage rate < 0.076 g/s for 20% power and flow
Friction < 1.5 lb drag per rotor
Accommodate dimensional changes from wear, thermal expansion, fabrication tolerances, tolerance stack up. Requires compliance of ~15 x 10^-3 inches
Manufacturable in large volume
Cost effective
MECHANOLOGY, LLC 10
Single Vane Test Machine Features• Designed for Development of Vane Seals
• Preserves Dimensional Scale of 50 kW TIVM / CE
• Leverages Existing Test Stand Hardware and Instrumentation
• Fast Turn Around Time for Test Specimens
• Static Sealing
• Dynamic Sealing (to 15 m/s vane velocity)
• Gas Pressure and Temperature (4 kHz)
• Seal Friction via Load Cell
• Linear Servo Motor
Position feedback (5 micron)
Velocity control (0 to 15 m/s)
MECHANOLOGY, LLC 11
Leakage Rate vs Compliance For Several Seal Options Screening Test Summary Results
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.0000 0.0050 0.0100 0.0150 0.0200 0.0250 0.0300 0.0350 0.0400Compliance, in x 10^-3
Le
ak
Ra
te, g
/s
TARGET FOR 5% LEAKAGE AT FULL POWER
TARGET FOR 5% Leakage AT 20% POWER
SEVERAL CONCEPTS ELIMINATED
Two Seal Concepts Meet Full Power Requirements
MECHANOLOGY, LLC 12
Friction vs Compliance for Candidate Seals
0
0.5
1
1.5
2
2.5
3
3.5
0.0000 0.0050 0.0100 0.0150 0.0200 0.0250 0.0300 0.0350 0.0400
Compliance, in x 10^-3
Fri
cti
on
, lb
s
TARGET VALUE
Two Seal Design Concepts Meet Friction Requirement
MECHANOLOGY, LLC 13
Leakage vs Friction Tradeoff for 6 kW Shaft Power
0
0.5
1
1.5
2
2.5
3
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Leakage Mass Flow Rate, g/s
Co
mp
res
so
r S
ea
l F
ric
tio
n, lb
TARGET DESIGN
BETTER
WORSE
Two Seal Concepts Meet Leakage and Friction Requirements for 6 kW – Further Optimization Possible
MECHANOLOGY, LLC 14
Friction Coefficient vs Speed, Most Recent ANL Data
0
0.05
0.1
0.15
0.2
0.25
0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0
Speed, m/s
Fri
ctio
n C
oef
fici
ent
SS on PEEK 100% RH
SS on PEEK 18% RH
Brass on PEEK 34% RH
Brass on PEEK 100% RH
NFC on NFC 100% RH
NFC on NFC 30% RH
TARGET VALUE
Vane to vane coefficient of friction of <0.15 is achievable
MECHANOLOGY, LLC 15
Shaft Power vs % Power and Flow, DOE Guidelines, Seal "B" Characteristics and 3.2 atm Pressure
0
1
2
3
4
5
6
7
0 20 40 60 80 100 120
Percent of Full Power and Flow
Sha
ft P
ower
, kW
mu=0.1Mu=0.15
Parasitic power load of <6 kW appears to be achievable
MECHANOLOGY, LLC 16
Future Plans
Complete seal measurements for combined leakage and friction – confirm satisfactory performance of at least one design – August 2003
Perform porting feature measurements to confirm satisfactory performance – August 2003
Complete investigation of additional innovation with potential to reduce shaft power by > 1kW.
Build fully operational prototype with selected seals and ports – measure integral performance
With accelerated funding, August 2004 At planned funding rate, September 2005
Integrate high efficiency motor – measure performance, deliver to Argonne National Laboratory for testing
With accelerated funding, September 2004 At planned funding rate, September 2005