Microchannel Heat

MICROCHANNEL HEAT EXCHANGER

PREPARED BY

ANAND R.NADGIRE F.Y.M.Tech(MIS No. 121025015)

2010-11

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Miniaturization & microchannel

conceptMiniaturization :-

Process of making something very small using modern technology

Microchannels :- Micro refers to something small

than usual considering particular scale Channels refer to passage of flow

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

OVERVIEW

Microchannel exchanger definitionManufacturing of Microchannel HexPerformance parameters and

comparisonMicrochannel technology advantages Implementation Challenges

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Microchannel consideration :

Mehandale etal :Flow in terms of ‘channel dimension’ Cd

1 μm < CD < 100 μm : Microchannels

100 μm < CD <1 mm : Minichannels

1 mm < CD < 6 mm : Compact passages

6 mm < CD : Conventional passages

Obet :Flow in terms of ‘hydraulic diameter’ Dh

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Microchannel Hex definition

MICR OCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.)

Manufacturing of mHex

MICR OCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Performance:Higher heat transfer coefficients

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

mHex performance comparison

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Performance :Manageable pressure

drop

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Performance :Increased volumetric heat flux

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Advantages :Higher performance

High volumetric heat fluxModest pressure dropCompact hardware for space critical

applicationRobust design

Proven manufacturing processDemonstrated mechanical integrity

Scalable technologyRepeatable designEffective flow distribution

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Implementation challenges

Cost

Reliability

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Cost :

Overall cost determined by

Equipment costsInstallation costsProcess productivity

Attractive costs for application that

Require expensive material of construction,e.g. nickel allot steel ,alluminiumInvolve multiple streamsDemand close approach temperature

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Reliability :

Three performance aspects impact reliabilityFouling/pluggingServiceParticulate sizeSurface chemistrySolid contentCorrosion On-stream factor Frequency of servicingMaintenance access

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Conclusion :

Microchannel provide high heat transfer coefficient because of their small hydraulic diameter

Though the implementation method is costly but its performance allow to use it effectively

Reduction in mass and volume allows it to use in various applications

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Future workThermal view of the microchannel heat exchanger

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

Referenceswww.velocys.comR.K.Shah & D.P.Sekulic ,Fundamental

of heat exchanger design, John Wiley & sons,2003.

D.B.Tuckermann,R.F.W.Pease,High performance heat sinking for VLSI,IEEE electron device letters.

N.T.Obet,”Towards the better understanding of friction and heat/mass transfer in microchannel – Literature review” ,Microscale thermo physical engg.

www.nasa.govMICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)

MICROCHANNEL HEAT EXCHANGER F.Y.M.Tech(C.O.E.P)