Micro structured heat exchangers

Micro-Structured Heat Exchangers & Reactors for ISRU

A. McCandless1, S. Motakef2, D. Guidry1, and M. Overholt2

1International Mezzo Technologies, Inc.2Cape Simulations, Inc.

November 2, 2004

New Enabling New Enabling TechnologyTechnology

High performance micro-High performance micro-machined thermo-chemical machined thermo-chemical devices for energy conversion devices for energy conversion and In-Situ Resource Utilization:and In-Situ Resource Utilization:– Heat ExchangersHeat Exchangers– ReactorsReactors

Core Technology

Micro-manufacturing – devices with micro-scale

features (10’s of microns) over macro-scale dimensions of (1-100 cm)

Micro-Channel Micro-Channel Thermo-Chemical DevicesThermo-Chemical Devices

Applications for Moon & Mars Applications for Moon & Mars Missions:Missions:– Propellant productionPropellant production– Fuel cell reagant productionFuel cell reagant production– Human habitat power & life support Human habitat power & life support

systemssystems

High Temp. ProcessesHigh Temp. ProcessesCandidate Process Output Operating

Temp.Equipment Needed

Hydrogen Reduction of Ilmenite

Fe, O2 900 oC 25C

High-Temp. Heat Exchanger Condenser

Carbo-thermal Methane Reduction

Fe, Si, O2 1625 oC;250 oC 25 oC

High-Temp. Heat ExchangerLow-Temp. Heat Exchanger

Vapor Pyrolysis O2, Fe, Al, Ca 2000 oC High-Temp. Heat Exchanger

Zirconia Solid CO2

Oxide Electrolysis

O2 900-1000 oC Catalytic Reactor High-Temp. Heat Exchanger

Sabatier Catalytic Reaction

H2O, CH4 200-300 oC Catalytic ReactorLow-Temp. Heat Exchanger

Reverse Water Gas Shift Reaction

H2O 400-650 oC. Catalytic ReactorMid-Temp. Heat Exchanger

Methane Reforming H2O, CH4 250 oC. Catalytic ReactorLow-Temp. Heat Exchanger

Hydrothermal Reduction of Mars soil

H2O, Fe 1000 oC High-Temp. Heat Exchanger

Lunar

MarsSource:

R.S. Baird


Heat Exchangers:Heat Exchangers:Micro-structured surfaces Micro-structured surfaces

lower diffusive thermal lower diffusive thermal resistances resistances

Higher performance Higher performance per per weight & volumeweight & volume


ReactorsReactors– Reduced resistance to mass transferReduced resistance to mass transfer– Intimate thermal exchange between Intimate thermal exchange between

catalytic reactor and heat catalytic reactor and heat exchangerexchanger

– Intimate thermal coupling of endo- Intimate thermal coupling of endo- and exo-thermic reactionsand exo-thermic reactions

– Accurate control of reaction Accurate control of reaction temperaturetemperature

– Non-Equilibrium chemical productsNon-Equilibrium chemical products

Micro-channels in Cross Micro-channels in Cross Flow Heat ExchangersFlow Heat Exchangers

In-plane cross section

Cross Flow Gas-Liquid Heat Exchangers

Liquid Inlet

Liquid Outlet Heat Exchange Panel

Gas Flow

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

0 2 4 6 8 10 12

SCFM/in2

W/K

/in

2

Lytron M10-080 Lytron 4320

Lytron 4105 Lytron M05-050

Lytron M14-120 Lytron M14-240

Lytron AS04-05 Lytron AS06-08

Lytron AS08-10 Lytron 4120

Lytron 4210 Lytron 4220


MEZZO 2 Panels MEZZO 1 Panel

Comparison with Existing Technology

Heat Transfer Per Unit of Frontal Area

0

2

4

6

8

10

12

14

0 2 4 6 8 10 12

SCFM/in2

W/K

/in

3




Lytron M14-240 Lytron AS04-05




MEZZO 1 Panel MEZZO 2 Panels

Heat Transfer Per Heat Transfer Per Unit VolumeUnit Volume

Comparison with Comparison with Existing TechnologyExisting Technology

Comparison with Comparison with Existing TechnologyExisting Technology

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 2 4 6 8 10 12

SCFM/in2

inch

H20




Lytron M14-240 Lytron AS04-05




MEZZO 1 Panel MEZZO 2 Panels

Pressure Per Pressure Per Unit Frontal AreaUnit Frontal Area


Compact PlateFin Heat Exchanger


Comparison with a truck radiator: the same heat transfer per Comparison with a truck radiator: the same heat transfer per frontal area, but much higher performance per volume & mass.frontal area, but much higher performance per volume & mass.

Example of Packaged HXExample of Packaged HX

Corrugated Heat Corrugated Heat Exchangers Yield Ultra Low Exchangers Yield Ultra Low Frontal AreaFrontal Area

Heat exchanger can be inside the duct!

Lithography

Metalization

Post Machining

Electroplating

Molding

LIGA Process

Advantages of LIGA

Tall/deep structures up to 3 mm/high aspect ratios: up to 100

Vertical sidewalls: 1um/1000 um slope Smooth sidewalls: less than 30 nm

variations Lateral dimensional control: better than

1 um Materials: Metal, Ceramic, Polymer Low per-unit manufacturing cost

Additional Types of Heat Additional Types of Heat ExchangersExchangers

Gas – GasGas – Gas Liquid – LiquidLiquid – Liquid Vapor – GasVapor – Gas Vapor – LiquidVapor – Liquid

Micro Jet Cooling Array Micro Jet Cooling Array

Systems for removal of very high heat fluxes

Micro Jet Cooling ArrayMicro Jet Cooling Array

Single phase impingement cooling >100 impinging microjets/cm2

Very high heat transfer coefficients Easily removes 1kW/cm2 of heat

4-kWatt Cold Plate4-kWatt Cold Plate

Ceramic Micro-channel Ceramic Micro-channel DevicesDevices

Applications:Applications:– High Temperature Heat High Temperature Heat

ExchangersExchangers– High Temperature ReactorsHigh Temperature Reactors– RecuperatorsRecuperators


AdvantagesAdvantages– Can go up to very high temperaturesCan go up to very high temperatures– Hospitable to a wide range of Hospitable to a wide range of

catalystscatalysts ChallengesChallenges

– Creation of high aspect ratio Creation of high aspect ratio structuresstructures

– Ceramic-Ceramic bondingCeramic-Ceramic bonding


500 500 m x 1.5 mm m x 1.5 mm structures in sintered SiNstructures in sintered SiN


Bonding of Ceramic PlatesBonding of Ceramic Plates– Strong ceramic-ceramic bonds Strong ceramic-ceramic bonds

createdcreated (Please see me for samples)(Please see me for samples)

– Mechanical tests to be conducted Mechanical tests to be conducted shortlyshortly


Building Block:Building Block:

Micro-machined ceramic panelMicro-machined ceramic panel


Counterflow fluids in alternating layers very effectively coupled via fins

Individual ceramic plates, aligned, pressed together, then sintered

Fins:Length 1.5-2.5 mmWidth at base: 300 mWidth at tip: 200 mGap Between Fins 300-400 m


Counter FlowCounter Flow

Examples of Ceramic Heat Exchangers & ReactorsExamples of Ceramic Heat Exchangers & Reactors

Cross FlowCross Flow DogboneDogbone


Gas Turbine Recuperator for Gas Turbine Recuperator for UMAVUMAV– 81% effectiveness81% effectiveness– 30 kW capacity30 kW capacity– Weight = 2lbsWeight = 2lbs– Volume = 6” x 2” x 6”Volume = 6” x 2” x 6”

Additional Manufacturing Technologies

Surface Micromachining Tradition and Micro Electro Discharge

Machining (EDM) Sinker Wire

UV Lithography Etching Laser Drilling, Cutting, and Welding

Collaborators

Heat Exchangers/ Chemical Reactors

Honeywell, MDA, General Dyanmics, Praxair, EADS, Lockheed Martin, Intel, & M-DOT

MicroJet Cooling Lockheed Martin ONR, MDA, Army, & NRL

Integrated HX & Mechanical Seals

NAVAIR, G.E., Rolls Royce, ASI, & Cooligy

Regenerator MDA, Air Force, Ball, L.M., Raytheon, & N.G.

CollaborationsCollaborations

We are looking for opportunities We are looking for opportunities to collaborate on design, to collaborate on design, modeling, fabrication, and modeling, fabrication, and testing of heat exchangers and testing of heat exchangers and reactors.reactors.

Micro-Channel Micro-Channel Thermo-Chemical Thermo-Chemical

DevicesDevices

Thank You!Thank You!

Documents

Micro structured heat exchangers