Ceramic Microchannel Devices for Thermal Management. C. Lewinsohn, J. Fellows, and H. Anderson Ceramatec, Inc. Salt Lake City, UT

Transcription

1 Ceramic Microchannel Devices for Thermal Management C. Lewinsohn, J. Fellows, and H. Anderson Ceramatec, Inc. Salt Lake City, UT

2 The Right Size for The Right Physics centi milli micro 2

3 Multiscale Structure micro milli centi 3

4 Multiscale Physics Scale micro milli centi Phenomena Gas separation, liquid-phase capillary forces, heat conduction, microelectronic integration, chemical reactions Gas transport/mixing, liquid transport/mixing, Industrial (High volume) mass and heat transport 4

5 Applications of Multiscale Microsystems Device Scale Structure Scale Structure Application micron microchannels submicron porous Energy, layers with Chemicals micron and submicron pores Microfluidic membrane reactor Compact Heat exchanger Planar, heat pipe micron microchannels submicron to millimeter porous layers with micron and submicron pores, foams micron microchannels submicron porous layers with micron and submicron pores Energy, Chemicals Microelectronics 5

6 Benefits of Ceramic Microsystems Properties of ceramics: electrical, magnetic, ionic, corrosion resistance, temperature resistance. Ceramics processing: laminated composites, tailored compositions, competitive costs. Compact designs: low volume, low cost, high reliability 6

7 Materials Selection Applications High-temperature heat exchangers Materials Silicon carbide (SiC), mullite Concentrated Solar PV AlN, Si 3 N 4 GaN diodes AlN, Si 3 N 4, SiC, LTCC Si MOSFET and IGBT AlN, Si 3 N 4, SiC, LTCC, HTCC, Al 2 O 3 7

8 Example: Compact Heat Exchanger Device Scale Structure Scale Structure Application micron microchannels submicron Energy, to Chemicals millimeter Compact Heat exchanger Tubular 6 Vessels 3.17m φ x 5.2m L M = 117,720 kg porous layers with micron and submicron pores, foams Planar Single Vessel 1.95m φ x 4.7m L M = 6,520 kg 8

9 Benefits of Ceramic Heat Exchangers Allow higher operating temperatures. Higher efficiency Reduced emissions Corrosion resistant Low cost 9

10 Microchannel Modeling Effectiveness vs Pressure Drop Channel height > 0.6 mm Low Reynolds number required for narrow channels Design parameters: Re = 600 channel height = 0.8 mm 10

11 Microchannel Modeling - Reliability Design parameters: System level failure probability = 1 x 10-6 SiC characteristic strength = 587 MPa, Weibull modulus = 6.4 Heat transfer layer thickness = 1.2 mm (0.048 ) 11

12 Diamond Channels Compact Heat Exchanger - design 50% Overlap Diamond HX Effectiveness Hexagonal Channels 50% Overlap Hex 50% Offset Hex 100% Offset Hexagonal Channels 100% Overlap.2 mm Riblets Channels w/ Riblets 0.1 mm 0.2 mm.1 mm Riblets Straight Channels Straight Channels T/T ( T/( T max Illustration courtesy M. Wilson 12

13 Compact Heat Exchanger - structure Scale-up Numbering-up Modular Stack Test Coupon Full-Size Wafer 13

14 Design Options Plate-Shell Design Block Design plate-side fluid in plate-side fluid out shell-side fluid out Insulated Shell Planar Modules shell-side fluid in Design options: PCHE, FPHE, etc. Plate-shell: microchannel plate/macrochannel shell Block design 14

15 Laminated Object Manufacturing 1 Powder processing 2 Slip preparation 3 Tape fabrication 1 - Control surface area for slip properties and sintering. 2 - Disperse materials for uniform tape properties (featuring and lamination), defect elimination and controlled sintering shrinkage. 3 - Dry tape uniformly for uniform thickness, minimal drying stress, without defects. 15

16 Laminated Object Manufacturing 4 Tape Tape featuring lamination 5 4 Optimise power and speed to minimise heat affected zone, maximize throughput, and obtain accurate channel dimensions. 4 Laser cut or punch depending on layer thickness and channel dimensions. 5 Complete lamination for structural integrity without deforming internal features. 16

17 Laminated Object Manufacturing 6 7 Sintering Stack Assembly 5 kw th 6 Controlled thermal cycle/environment for binder burnout and densification to make leak tight components while maintaining flatness without creating defects. 6 Complex designs require co-sintering dissimilar materials and porous and dense layers in the same component. 7 Requires robust ceramic-ceramic joining. 17

18 Microchannel Heat Exchanger Design Flexibility

19 Plate Design Plate Shell design Flow distribution to channels Flow distribution across plates 19

20 Microchannel Heat Exchangers Performance Metrics Performance Metric Value Thermal Duty 1 MW (heat) Hydraulic Diameter - Feed 636µ Hydraulic Diameter - Exhaust 1684µ Temperature Span (Inlet to Inlet) 450C to 950C Volume 1.0 m 3 Log Mean Delta Temperature 25C Overall Heat Transfer Coefficient 145 W/m 2 C Area Density (modular stack) 310 m 2 /m 3 Calculated values Scaleable from kw to MW Estimated ceramic heat exchanger cost: $ kw th Reference case: gas separation modules: 100 $/kw (independently verified by 3 rd party for DOE).

21 Test Apparatus 3-10 plate stacks

22 Test Apparatus 3-10 plate stacks Measurements Plate Temp in Plate Temp Out Channel Temp in Channel Temp Out Channel Pressure In Channel Pressure Out

23 Test Results 3 plate stack Preliminary results indicate good performance: Good pressure drop 4-5 kpa Maximum effective heat transfer coefficient 70 W/m-K Maximum effectiveness 65%

24 Further Risk Mitigation Support mitigation of key technical risks, especially lifetime: Continue study and validation of design tradeoffs between design for manufacturing and performance. Materials testing: oxidation. Assembly of 5-10 kw stacks and n * 1000 h testing. Verify reliability of integration with balance of plant, especially hot gas manifolds. Verification of viable manufacturing costs for robust and scalable processes.

25 Planar Heat Pipe Device Scale Structure Scale Structure Application Planar, heat pipe micron microchannels submicron porous layers with micron and submicron pores Microelectronics Convective Cooling Heat Rejection to Fins Forced Air Liquid Wicking Benefits: Heat from High Power IC Vapor Flow High effective thermal conductivity in compact design and low thermal stresses. Passive or active heat dissipation. 25

26 Planar Heat Pipe - structure Low Energy Fluid Return (capillary wick) micro macro -Dense Skin -Porous Wick -Contiguous Gas Channels -Porous Wick -Dense Skin Gas Phase Flow 26

27 Planar Heat Pipe - performance Design concepts validated. Manufacturing via microsystem approaches viable. Component substructures function as designed. Effective conductivity and heat flux to be measured. 27

28 Summary Design parameters, materials, and commercially viable fabrication processes demonstrated for high effectiveness, low pressure drop, mechanically reliable ceramic, compact heat exchangers. Current focus is high-temperature heat exchangers for power generation applications. Methodology is also viable for micro-electronics cooling

29 Acknowledgements US DOE NETL Crosscutting Technologies Award DE- FE Project Manager Richard Dunst. Ceramatec: Angela Anderson, Kiley Adams. CoorsTek: SiC powder

30 Compact Heat Exchanger - reliability Tubular Designs Planar Designs Reliability P f 1 = 1 exp m σ, V σ 0 Where: m ( x, y z) dv plate-side fluid in shell-side fluid out plate-side fluid out σ(x,y,z) = σ(p) + σ( T) σ 0 = Weibull Material Scale Parameter m = Weibull Modulus Insulated Shell Planar Modules shell-side fluid in Stress Metrics V ceramic = 9.85m 3 σ hoop = 2.5 MPa S.F. = V ceramic = 0.71m 3 σ tensile = 1.6 MPa S.F. =