Heat Exchangers is a piece of equipment built for efficient is a discipline of thermal engineering that concerns the generation, use,
conversion, and exchange of thermal energy. Heat transfer is classified into various mechanisms, such as
thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of
mass of differing chemical species, either cold or hot, to achieve heat transfer. While these mechanisms have distinct characteristics, they
often occur simultaneously in the same system and from one medium to another. The media may be separated by a solid wall, so that they never
mix, or they may be in direct contact.
Heat Exchangers are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment. The classic example of a heat exchanger is found in an internal combustion engine in which a circulating fluid known as engine coolant flows through radiator coils and air flows the coils, which cools the coolant and heats the incoming air.The final major form of heat transfer is by radiation, which occurs in any transparent medium but may also even occur across vacuum (as when the Sun heats the Earth). Radiation is the transfer of energy through space by means of electromagnetic waves in much the same way as electromagnetic light waves transfer light. The same laws the radiant transfer of heat.
Heat Exchangers counter current design is the most efficient, in that it can transfer the most heat from the heat (transfer) medium due to the fact that the average temperature difference along any unit length is greater. See countercurrent exchange. In a cross-flow heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger. Heat exchangers are designed to maximize the surface area of the wall between the two fluids, while minimizing resistance to fluid flow through the exchanger. The exchanger's performance can also be affected by the addition of fins or corrugations, which increase surface area and may channel fluid flow or induce turbulence.