Counter Flow Heat Exchanger Design

In counter flow heat exchangers the fluids enter the exchanger from opposite ends.

Counter flow heat exchanger design.

Counter flow heat exchanger the diagram above shows a shell and tube heat exchanger. A primary surface heat exchanger is one which does not involve any secondary surfaces such as fins ribs dimples etc. But of the three the counter flow heat exchanger design is the most efficient when comparing heat transfer rate per unit surface area. Each of the three types of heat exchangers parallel cross and counter flow has advantages and disadvantages.

In the counter flow setup the fluids are travelling along. The heat exchanger design equation can be used to calculate the required heat transfer surface area for a variety of specified fluids inlet and outlet temperatures and types and configurations of heat exchangers including counterflow or parallel flow. With parallel flow the fluids are travelling through the heat exchanger in the same direction where as a counter flow installation will have the fluids flowing against each other in opposite directions. The counter current design is the most efficient in that it can transfer the most heat from the heat transfer medium per unit mass due to the fact that the average temperature difference along any unit length is higher.