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Post on 19-Dec-2015
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DESCRIPTIONPresentation on Heat Exchanger
Introduction to Heat Exchangers
What is heat transfer? How Is Heat Transferred?What is Heat Exchanger?Classification of Heat ExchangersTypes of Heat Exchangers.Mean fluid Velocity and Boundary and their effect on the rate of heat transfer.Applications of Heat Exchangers
What is heat transfer?
Heat can transfer between the surface of a solid conductor and the surrounding medium whenever temperature gradient exists.
How Heat Is Transferred?
Types of ConvectionFree Convection
A device whose primary purpose is the transfer of energy between two fluids is named a Heat Exchanger.
Heat Exchangers TypesConcentric Tube (Double Piped)Shell and Tube Heat ExchangersCompact Heat ExchangersCross Flow Heat Exchangers
The closed-type exchanger is the most popular one.One example of this type is the Double pipe exchanger.
Principle of Heat ExchangerFirst Law of Thermodynamic: Energy is conserved.
ThTi,wallTo,wallTcRegion I : Hot Liquid-Solid ConvectionNEWTONS LAW OF CCOLINGRegion II : Conduction Across Copper WallFOURIERS LAWRegion III: Solid Cold Liquid ConvectionNEWTONS LAW OF CCOLINGTHERMALBOUNDARY LAYER
Applications of Heat ExchangersHeat Exchangers prevent car engine overheating and increase efficiencyHeat exchangers are used in Industry for heat transferHeat exchangers are used in AC and furnaces
*****Heat exchangers are devices that provide the flow of thermal energy between two or more fluids at different temperatures.Used in wide range of applicationsClassified according to:Recuperators/RegeneratorsTransfer processes: direct and indirect contactConstruction Geometry: tubes, plates, extended surfacesHeat Transfer Mechanisms: single and two phaseFlow arrangements: parallel, counter, cross-flow
*****Carprevent overheating with high performance cooling applicationsMaintain fluids at optimal temperature such that engine efficiency is increased and component wear minimizedBoilers and condensers are opposite processes used in industry -Boilers used to create steamsometimes to drive steam driven turbines -condenseros bring steam back to liquid for reuseDistillation set-ups typically use condensers to condense distillate vapors back into liquid.
Ultimately, condensers-cool refrigerant vapor back to liquid-- sub cooled liquid flows out of the condenser and into the evaporator where it absorbs heat from air in the surrounding pipe and generates cold air. Air conditioners utilize a closed heat exchange system that separates the hot and the cold fluids. Energy is transported via convection between the fluid and inner pipe surface, conduction through the pipe and then convection from the outer pipe surface into the second fluid. This closed system is very similar to the one examined in this lab experiment, and its widespread applicability is why this lab was designed.