Classification of Heat Exchangers
Heat exchangers are the devices that are used to transfer heat from one fluid to other fluid. Many heat exchangers are been used by us in our daily lives that include condensers and evaporators that are used in air conditioning units and refrigerators.
Boilers and condensers are included in the large industrial heat exchangers in thermal power plants. The radiators and oil coolers are the form of heat exchangers in the vehicles. These heat exchangers are most abundant in all process industries and chemical industries. There are wide varieties of heat exchangers that are used for diverse purposes where the construction also differs widely. The heat exchangers can be classified into different types based on few fundamental concepts. Most frequent types of heat exchangers are used for the analysis and the design methodologies.
The heat exchanger classification is based on the devices basic operation, construction and the type of flow and their arrangements. The heat exchangers are classified as:
- Recuperators and Regenerators
- The direct contact transfer and indirect contact transfer processes.
- Based on geometry as tubes, plates and extended surfaces.
- The heat transfer mechanisms as single phase and two phase flows.
- Based on the flow arrangement as parallel flow, counter flow and cross flow.
This is used to recover the waste steam discharge from the industrial applications.
- Counter flow heat exchangers have larger LMTD value and also greater potential recovery. This permits even a smaller area of heat exchange. This will refer to a less expensive heat exchange equipment of the given application.
- In parallel flow heat exchangers the initial heating rate is very high and this advantage is used where the tube walls are to be developed with their temperature.
- The rapid initial heating will help to decrease the fluid viscosity that in turn reduces the pumping requirement which reduces the overall cost of the application.