Heat exchangers are systems used to move thermal energy from a hot flowing substance to a cold flowing substance. A plate heat exchanger consists of a series of plates with the two liquids flowing through passages in the plates. Plate heat exchangers are commonly found in electronic devices, especially computers, where heat must be drawn away from processors, like the CPU, to allow the processor to function correctly. the method of sizing a plate heat exchanger depends on the construction material, the amount of heat being transferred and the difference in the temperatures.
Determine the temperature difference between the input of the hot substance vs. its temperature at output. The output temperature cannot drop below the input temperature of the cold substance. Subtract the hot input temperature from the hot output temperature.
Lookup the heat transfer coefficient for the heat exchanger system. Plate heat exchangers typically are made of steel or aluminium, which both have heat transfer coefficients of 25.0W/m^2 K.
Determine the amount of heat you need to transfer within a specific time frame to get the heat transfer rate. The amount of heat should be in BTUs while the time period is in hours. Values typically range from 1 to 400 BTU/h.
Divide the heat transfer rate by the heat transfer coefficient times the temperature difference to get the transfer surface area. The transfer surface area is the amount of surface area both substances will need to come in contact with while in the heat exchanger.