There is not a lot of public knowledge about heat exchangers; they are generally only discussed in mechanical and chemical engineers circles. Yet they are found all over the world in common appliances like air conditioners and refrigerators, the radiator in motor vehicles is an another example.
The basic principle behind heat exchangers is the transferring of heat from one medium to another. For example the car radiator allows hot fluid from the engine to be cooled when the fins of the radiator radiate the heat into the air that flows over its surface. Some factors that influence the efficiency of heat exchangers are the fluids rate of flow and the total surface area of the wall that separates the fluids. To increase the surface area of the contact wall fins and corrugations are added, this is an effective measure.
Of The 4 types of heat exchanger the shell and tube configuration is most common and also relatively easy to maintain. This system has multiple tubes with fluid running inside them and simultaneously running over them. This allows a heat transfer to take place.
Another one is regenerative type that is common in gas cooling applications has the effect of taking heat produced in one process and transferring it to another also known as heat recovery. Plate and intermediate fluid exchangers are the other types.
The plate configuration uses the same technique as the shell and tube just here the fluid is made to flow through layers of cavities between multiple plates the result is a large surface area. This configuration is considered to have the best thermodynamic performance for this application and it is widespread in the engineering world. But it is more time consuming and labour intensive to fabricate than a shell tube heat exchanger.
The way the fluid flows through the these equipments has been divided into 3 major groups. These flow arrangements are cross-flow, counter-flow and parallel-flow. Of these the counter-flow configuration transfers the greatest amount of heat.