Counter Flow Heat Exchanger Example

The counter current design is the most efficient in that it can transfer.

Counter flow heat exchanger example.

Consider a parallel flow or counterflow heat exchanger consisting of fluid 1 fluid 2 and the wall separating these two fluids. There are three primary classifications of heat exchangers according to their flow arrangement. One starts off hot at 60 c the second cold at 20 c. We combine these two types together with an index n to indicate the flow direction of fluid 2.

A counterflow heat exchanger will require less heat exchange surface area than a parallel flow heat exchanger for the same heat transfer rate and the same inlet and outlet temperatures for the fluids. A cocurrent heat exchanger is an example of a cocurrent flow exchange mechanism. In a shell and tube heat exchanger coolant usually flows through the central tube core to cool hot oil water or air which passes over and around the tubes. Crossflow parallel flow and counterflow heat exchanger configurations are three examples.

For a parallel flow heat exchanger n 0 and for a counterflow heat exchanger n 1. In parallel flow heat exchangers the two fluids enter the exchanger at the same end and travel in parallel to one another to the other side. A thermoconductive membrane or an open section allows heat transfer between the two flows. In the parallel flow arrangement of figure 18 8 a the hot and cold fluids enter at the same end flow in the same direction and leave at the same end.

In counter flow heat exchangers the fluids enter the exchanger from opposite ends. The direction in which the two fluids travel through the heat exchanger can be either parallel flow or counter flow.