Heat Exchangers are devices used to transfer heat between one or more fluids. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact.
They are widely used in space heating, refrigeration, air conditioning. They are also used in power stations, chemical plants, petrochemical plants. In also used for petroleum refineries, natural-gas processing, and sewage treatment.
What are they used for ?
In all kinds of places, usually working to heat or cool buildings or helping engines and machines to work more efficiently. Refrigerator and Air Conditioners, use in the opposite way from central heating systems:
Finally, the remove heat from a compartment or room where it’s not wanted and pump it away as a fluid to another place.