When two physical systems exchange their thermal energy, a heat transfer takes place. And a device which aids in heat exchange between two fluids is known as a heat exchanger. Heat exchangers are widely used for domestic and well as industrial uses. Heat exchangers find their place right from air conditioners at home to engines and machineries in industries.
The types of heat exchangers available are so varied and vast; your pick from among the lot depends on why and what do you need it for. Heat exchangers are also available online and select the one you need accordingly at AIC Heat Exchanger.
Heat exchangers are classified into many types based on numerous parameters.
- Based on the type of fluids: The types of fluids are liquid and air. So a heat exchange may take place between air to air, air to liquid or liquid to liquid. That means you may have an air to air heat exchanger or water to water exchanger or even a water to air exchanger depending on the application.
- Based on contact type: Direct contact type refers to when the two fluids are directly in contact and a heat exchange takes place. In indirect contact type, the two fluids never physically mix with each other except for the heat transfer taking place between them.
- Based on the count of fluids: There might be heat exchange between two fluids only or among three fluids or among any number. Again this is application specific.
- Based on the construction of heat exchanger: Shell and tube heat exchanger, flat plate heat exchanger, brazed plate heat exchanger, plate and fin heat exchanger; these are some of the many types of construction of the heat exchangers. The type what one needs depends on many factors and what function it is to serve.
- Based on the direction of fluid flow: The fluids inside the heat exchangers can flow parallel to each other in the same direction. When the fluids flow parallel to each other but in the opposite direction then it is a counter flow type of heat exchanger. This is the most efficient type of heat exchanger. In cross flow arrangement or a normal flow, there is roughly perpendicular flow between the fluids in the exchanger.
- Based on the number of passes: The fluids in the heat exchanger can flow once through the heat exchanger or it can have multiple passesin the exchanger till the required heat transfer is achieved between the two fluids.
- Based on phase conversion: Here the fluids can have phase changes to facilitate heat exchange. Like, a gas condensing to liquid form or a liquid evaporating to gas form on heating; the fluids change phases to get the desired heat transfer.
The above classifications help in selecting the right type of heat exchanger required in the heat transfer process. The heat exchanger design and construction combines all the above aspects as per the requirements and the heat exchanger calculations are done to achieve the right amount of heat transfer.