Post on 07-Jun-2020
Micro- & Nano-Technologies Enabling More Compact, Lightweight Thermoelectric Power Generation & Cooling Systems
2011 Thermoelectrics Applications WorkshopSan Diego, CA5 January 2011
Terry J. Hendricks, Shankar Krishnan, Steven Leith
Pacific Northwest National LaboratoryEnergy & Efficiency Division
MicroProducts Breakthrough InstituteCorvallis, OR
We Sincerely Thank Our Sponsor: John Fairbanks, Gurpreet SinghU.S. Department of Energy
EERE - Office of Vehicle Technologies
Advanced Thermoelectric System DesignSingle & Segmented Material TE Legs
2
Qh,out
Qc,in
Power InPower In
Th
N
Tc
Compartment Cooling Flow
Hot-Side Rejection Flow
Tcold
Cold Side Heat Exchanger
Hot Side Heat Exchanger
Tamb , mhAmbient
•
Tcabin , mc•
P
I
Power InPower In
Th
N
Tc
Compartment Cooling Flow
Hot-Side Rejection Flow
Tcold
Cold Side Heat Exchanger
Hot Side Heat Exchanger
Tamb , mhAmbient
•Tamb , mhAmbient
•
Tcabin , mc•Tcabin , mc•
P
I
Thermoelectric Heating/CoolingLow-Temperature Systems
Qh,in
Power Out
Tcold
N1
Thot
Industrial & Vehicle Exhaust Flow
Environment Ambient Flow
Tcold
Qc,out
External Load, Ro
Hot Side Heat Exchanger
Cold Side Heat Exchanger
Tamb , mcAmbient
•
Tex , mhExhaust
•
P2
Thermoelectric Power GenerationHigh-Temperature Systems
P1
N2
Generally Do Cascading Rather Than Segmenting to Achieve Large ∆T
Advantages of SegmentingDepends on Available ∆T
0 200 400 600 800 1000 12000
0.02
0.04
0.06
0.08
0.1
0.12
Power [W]
Max
imum
Effi
cien
cy
0.237(W/cm2) →
0.403(W/cm2) →
0.589(W/cm2) →
0.808(W/cm2) →
1.06(W/cm2) →
1.34(W/cm2) →
1.66(W/cm2) →
2.02(W/cm2) →
2.41(W/cm2) →
2.83(W/cm2) →
3.28(W/cm2) →
3.77(W/cm2) →
←T h
=490
(K)
←T h
=515
(K)
←T h
=540
(K)
←T h
=565
(K)
←T h
=590
(K)
←T h
=615
(K)
←T h
=640
(K)
←T h
=665
(K)
←T h
=690
(K)
←T h
=715
(K)
←T h
=740
(K)
←T h
=765
(K)
←T h
=790
(K)
←T h
=815
(K)
←T h
=840
(K)
←T h
=865
(K) Tcold=380 (K)
Tcold=415 (K)Tcold=450 (K)Constant Thot
0 200 400 600 800 1000 12000
0.02
0.04
0.06
0.08
0.1
0.12
Power [W]
Max
imum
Effi
cien
cy
98(W/kg) →
165(W/kg) →
243(W/kg) →
335(W/kg) →
441(W/kg) →
561(W/kg) →
696(W/kg) →
846(W/kg) →
1012(W/kg) →
1194(W/kg) →
1392(W/kg) →
1608(W/kg) →
1841(W/kg) →
←T h
=490
(K)
←T h
=515
(K)
←T h
=540
(K)
←T h
=565
(K)
←T h
=590
(K)
←T h
=615
(K)
←T h
=640
(K)
←T h
=665
(K)
←T h
=690
(K)
←T h
=715
(K)
←T h
=740
(K)
←T h
=765
(K)
←T h
=790
(K)
←T h
=815
(K)
←T h
=840
(K)
←T h
=865
(K) Tcold=380 (K)
Tcold=415 (K)Tcold=450 (K)Constant Thot
TE Power GenerationHeat Exchanger / TE Device Integration Requirements
Regions of Higher Specific Power Also Associated with Higher Heat Flux Regions
Hot Side Heat Exchanger Dictates: TE Specific Power TE Power Flux TE Volumetric Specific
Power
Heat Fluxes > 15 W/cm2 inPreferred Design Regimes Hot-side Cold-side
Segmented Skutterudite/Bi2Te3 Materials
hm
Preferred TEDesign Regime
Texh= 873 KTamb = 300 K
= 0.1 kg/sUAh = 377 W/K
TE CoolingHeat Exchanger / TE Device Integration Requirements
250 300 350 400 450 500 550 6000
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Cooling Capacity [W]
Max
imum
CO
P
←1421(W/kg)
←1294(W/kg)
←1173(W/kg)
←1057(W/kg)
←Th =340(K)
←Th =337(K)
←Th =334(K)
←Th =331(K)
←Th =328(K)
←Th =325(K)
←Th =322(K)
←Th =319(K)
←Th =316(K)
Tcold=280 (K)Tcold=270 (K)Tcold=260 (K)Constant Thot
Distributed Cooling Systems
Typical COP – Cooling Capacity – Power / Mass Relationship Shown Distributed TE Cooling Systems
Create Lower Heat Flows per Unit
Higher COP’s Lower Power / Mass
Generally Right Directions forAutomotive Distributed Cooling
p-type NPB BixSb2-xTe3*
n-type Bi2Te3 – Bi2Se3
* Poudel, B., Hao, Q.H., Ma, Y., Lan, Y., Minnich, A. Yu, B.,Yan, X., Wang, D., Muto, A., Vashaee, D., Chen, X., Liu, J.,Dresselhaus, M.S., Chen, G., Ren, Z., 2008, “High-Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk Alloys,” Sciencexpress, 10.1126, science.1156446.
UAc = 40 W/KTcabin = 298 K
100 150 200 250 300 350 400 4500
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Qc Per Mass[W/kg]
Max
imum
CO
P
←T h
=340
(K)
←T h
=337
(K)
←T h
=334
(K)
←T h
=331
(K)
←T h
=328
(K)
←T h
=325
(K)
←T h
=322
(K)←
T h=3
19(K
)←T h
=316
(K)
Tcold=280 (K)Tcold=270 (K)Tcold=260 (K)Constant Thot
p-type NPB BixSb2-xTe3
n-type Bi2Te3 – Bi2Se3
UAc = 40 W/K
Tcabin = 298 K
Preferred TEDesign Regime
TE CoolingHeat Exchanger / TE Device Integration Requirements
0.4 0.5 0.6 0.7 0.8 0.9 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Qc Per Area [W/cm2]
Max
imum
CO
P
←T h
=340
(K)
←T h
=337
(K)
←T h
=334
(K)
←T h
=331
(K)
←T h
=328
(K)
←T h
=325
(K)
←T h
=322
(K)
←T h
=319
(K)←
T h=3
16(K
)
Tcold=280 (K)Tcold=270 (K)Tcold=260 (K)Constant Thot
Preferred TEDesign Regime
p-type NPB BixSb2-xTe3
n-type Bi2Te3 – Bi2Se3
UAc = 40 W/K
Tcabin = 298 K
Distributed TE Cooling Systems Generally Move Into Regions of: Higher COP’s Higher Specific Cooling Capacity (Compact, Lightweight Systems) Higher Heat Fluxes (Higher Heat Transfer Coefficients)
Generally Higher Performance Heat Exchanger SystemsRequired
PNNL Developing High-Performance Microtechnology Heat Transfer Technologies
TE Power Generation From TQG Exhaust Energy Recovery Hot-Side Heat Exchanger Designs Being Developed & Refined CFD Analyses & Experimental Testing Helping to Refine Designs Design Performance Goals:
High Thermal Transfer Flux (~10-12 W/cm2) in Hot-Side Heat Exchanger Low Pressure Drop (< 1 psi) Heat Flux vs. Pressure Drop Characteristics Quantified for Different Design Approaches
Different Materials Can Be Used: Stainless Steel, Inconel, Haynes Materials, Ceramics
COMSOLCFD Analysis
Air Supply HeatersWater-Cooled Heat Sink
Hydrodynamic Conditioning& Mixing
Design Point
60 kW TQG Design Conditions: 0.158 kg/sec, 780 K
Rectangular Honeycomb Design
Design Target
Several Workable Design Points Identified
ε = 0.93
7
Co-Functional Power / Cooling Systems Co-Functional Integration of 3 Power & Cooling Technologies
Organic Rankine Cycle Based Cooling Thermoelectric Power Generation Micro/Nano Heat Transfer Technologies (Microchannel Heat Exchangers)
System Designed, Fabricated & Tested at PNNL MBI TE Topping Cycle
Step-Down (Lower) Input Temperatures to ORC
Simultaneously Produce Useful Power
E/C ORC to Provide Useful Cooling Capacity Known & Demonstrated Components in this Phase Reduce Cost & Risk & Development Time
Microchannel Heat Exchangers Used toDramatically Reduce Volume & Weight
Funded by U.S. Army RDECOM
High Temperature HEX
Thermoelectric Generator
Expander/CompressorHeat Pump
Electrical Power
Heat Rejectionto SurroundingsHeat in from
Cooling Space
Hot ExhaustStream
ThermalResistance
ThermalResistance
Qin,H
Qout
Waste Heat forTotal Energy
RecoverySpentExhaust
Qtot,outQin
High Temperature HEX
Thermoelectric Generator
Expander/CompressorHeat Pump
Electrical Power
Heat Rejectionto SurroundingsHeat in from
Cooling Space
Hot ExhaustStream
ThermalResistance
ThermalResistance
Qin,H
Qout
Waste Heat forTotal Energy
RecoverySpentExhaust
Qtot,outQin
CFPC – Fabrication & Test First-in-Class, Pioneering System TEG Power System Uses
MicroChannel Heat Exchangers Stainless Steel Air HX On Hot-Side Aluminum R245fa HX on Cold-Side
High-Temperature Bi2Te3 Modules First-Ever 320°C Bi2Te3 Modules
System Size Dimensions: 30” X 30” X 19” Weight: ~100 kgs
System Fabrication Completed System Testing Completed
Exhaust Heat Simulated with Electrical Heater / Blower System
Stable System Operation Many Performance Metrics Satisfied
8
TEG Power System
Co-Functional System Build-up
ORC Boiler
Scroll Expander
MicroTechnology in Distributed TE HVAC Systems DOE Project in Advanced TE HVAC
Systems for Automobiles Zonal Climate Control for Thermal Comfort Compact Microtechnology Heat Exchangers
Reduce Weight & Volume Low Cost Manufacturing
Coupled with Compact TE HVAC Systems Wicking Systems for Water Management
Leveraging Nano-Scale Coating Technology
Significant Microtechnology Cost Modeling Cost Sensitivities Identified Low-Cost Manufacturing Avenues Being Developed Sensitivities to Production Volumes Material and Process Cost Drivers
9
Hybrid / PHEV Vehicles
Nano-Scale Coatings
Cost Modeling Approach
PNNL Nano-Scale Coatings Impact Surface Hydrophobicity and Surface Boiling Heat Transfer ZnO on Al Substrate Rave = 315 nm θ = 20.3° Can Make Super-Hydrophilic
Surfaces θ= 0° Bare Aluminum
Substrate θ=104° Huge Ramifications on Water
Management / Transport
0.005 0.030 0.055 0.080 0.105 0.130 0.155
NaOH Concentration [mol/L]
10
30
50
70
90
Conta
ct
Angle
[d
egre
es]
Set 1Set 2
Heat Flux, kW/m2H
eatT
rans
ferC
oeffi
cien
t,kW
/m2 K
101 102 103
5
10
15
20
2530
Al - Unique Surface (18)Cu - 30 Contact Angle (Fl)Al - 20 Contact Angle (Fl)Bare Al
PNNL Developing High-Performance Microtechnology Heat Transfer Technologies TE Cooling / Heating
Automotive Distributed HVAC Systems A Number of Microtechnology Designs Are Being Investigated An Example of One Such Design Is Presented Here
Heat Transfer vs. Pressure Drop Characteristics Quantified
0.4
0.5
0.6
0.7
0.8
0.9
1
0.015 0.017 0.019 0.021 0.023 0.025 0.027 0.029 0.031 0.033 0.035
Volume of Metal, Liters
Effe
ctiv
enes
s
135
160
185
210
235
260
285
310
335
Hea
t T
ran
sfer
Rat
e, W
Copper
Aluminum
Effect of Channel Aspect Ratio on Effectiveness
Modeled Channel Aspect Ratio: 2:1 – 8:1
Wall Thickness on Order of 150 - 350 um
4 cm
2 cm
8 cm
4 cm
2 cm
8 cm
7
7.5
8
8.5
9
9.5
10
10.5
11
0.4 0.5 0.6 0.7 0.8 0.9 1
Effectiveness
Hea
t T
ran
sfer
Den
sity
(Q/V
olm
etal
), k
W/L
t.
Copper
Aluminum
Effect of Channel Aspect Ratio on Flux Density
4 cm
2 cm
8 cm
4 cm
2 cm
8 cm
Process-Based Microtechnology Cost Modeling Microtechnology Manufacturing Cost is Key to Automotive Applications Process-Based Cost Modeling
Cost Sensitivities Identified
Low-Cost Manufacturing Avenues Being Developed
Sensitivities to Production Volumes
Material and Process Cost Drivers
System Performance Modeling Integrated with Cost Modeling to Identify Low-Cost, Manufacturable Microtechnology Designs
Cost Modeling Incorporates Critical Process & Cost Elements Prioritizes R&D Investment Plans & Enables Business Decisions Compared 3 Process Approaches for Microtechnology Heat Exchanger
Design Discussed Above Cost Modeling for High-Temperature Exhaust Recovery Applications Cost Modeling for Low-Temperature Advanced Cooling Applications
Process Based Cost ModelingBottom-Up Approach to Estimating Cost of Goods Sold (COGS)
Based on Operation of Virtual Manufacturing Line – Breaks Down Cost by Unit Process
Cost of Goods Sold (COGS)
Variable CostsFixed Costs
Capital EquipmentMaintenance
Facilities/Buildings
Direct LaborDirect Materials
Indirect MaterialsUtilitiesProcess-Based Cost
Model Algorithm
Model Outputs
Start with Process Flow and Associated Equipment Set
Process COGS vs. Volume and ParetoCost SensitivityID Cost Drivers
Not IncludedOverhead & Profit
InsuranceTaxes
Inventory Management AccountingMarketing
Sales
Capital EquipmentLabor
MaterialsEnergy
FacilitiesMaintenance
Cost Elements
Model Inputs
Process Flow
Unit Process 1Unit Process 2Unit Process 3
Etc.
Process to Process ComparisonsDefine Fabrication Toolbox
Inform R&D Agenda
Contact: Steven.Leith@pnl.gov
$0
$20
$40
$60
$80
$100
$120
$140
$160
1,000 10,000 100,000 1,000,000
Prod
ucti
on C
ost (
USD
/Dev
ice)
Production Volume (Vehicles/yr)
Integrated HTX COGS Estimation and Pareto : Process "A"
Direct Materials
Sheet Cutting
Sheet Clean and Prep
Weld 1
Singulation 1
Weld 2
Singulation 2
8 HTX per Vehicle / Aluminum HTX / 2 cm x 4 cm x 8 cm HTX Dimensions
$155.00
$30.75$20.50 $19.50
Process Relies on Significant Laser Use Not a Good Design + Process MatchExisting, Scalable Fabrication Processes and OTS Production Equipment
$0
$5
$10
$15
$20
$25
$30
$35
$40
$45
1,000 10,000 100,000 1,000,000
Prod
ucti
on C
ost (
USD
/Dev
ice)
Production Volume (Vehicles/yr)
Integrated HTX COGS Estimation and Pareto : Process "B"
Direct Materials
Sheet Cutting
Sheet Clean and Prep
Braze 1
Singulation 1
Braze 2
Singulation 2
8 HTX per Vehicle / Aluminum HTX / 2 cm x 4 cm x 8 cm HTX Dimensions
$40.00
$7.50$4.50 $4.25
Direct Materials Primary Cost Driver at Production VolumesExisting, Scalable Fabrication Processes and OTS Production Equipment
$0
$5
$10
$15
$20
$25
$30
$35
$40
$45
$50
1,000 10,000 100,000 1,000,000
Prod
ucti
on C
ost (
USD
/Dev
ice)
Production Volume (Vehicles/yr)
Integrated HTX COGS Estimation and Pareto : Process "C"
Direct Materials
Sheet Cutting
Sheet Clean and Prep
Braze 1
Singulation 1
Braze 2
Singulation 2
8 HTX per Vehicle / Copper HTX / 2 cm x 4 cm x 8 cm HTX Dimensions
$46.50
$13.75$11.00 $10.50
Direct Materials Cost for Copper is 4x that for Aluminum Drives CostImproved Yield and Cycle Times in Copper Braze vs. Aluminum Braze
Vehicles HTX Units $/Unit Capital Equipment ($k) $/Unit Capital Equipment ($k) $/Unit Capital Equipment ($k)1,000 8,000 $153.90 $1,705 $40.09 $1,400 $46.48 $1,40010,000 80,000 $30.85 $5,455 $7.44 $1,400 $13.87 $1,400
100,000 800,000 $20.54 $43,830 $4.55 $2,550 $10.91 $2,0501,000,000 8,000,000 $19.55 $459,300 $4.19 $17,750 $10.61 $14,750
Process A Process B Process CAluminum Copper
Annual Volume
Summary - Process Comparisons
1.25 mm4 cm
2 cm
8 cm
1.25 mm4 cm
2 cm
8 cm
4 cm
2 cm
8 cm
Summary Microtechnology Thermal Systems Required to Enable Compact, Light weight
TE Systems TE Power Generation TE Cooling / Heating
Microtechnology Thermal Systems Successfully Integrating into TE Systems Process-Based Cost Modeling is Critical to Developing Low Cost
Manufacturing Pathways, Processes, and Materials Cost Modeling Incorporates Critical Process & Cost Elements Cost Sensitivities Identified Low-Cost Manufacturing Avenues Being Developed Sensitivities to Production Volumes Material and Process Cost Drivers Identified
System Performance Modeling Integrated with Cost Modeling to Identify Low-Cost, Manufacturable Microtechnology Designs
Prioritizes R&D Investment Plans & Enables Business Decisions
20
Questions & Discussion
We are What We Repeatedly do. Excellence, Then, is not an Act, But a Habit.
Aristotle
Thank you for your time and interest