Post on 17-Oct-2014
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)