Counter Flow Heat Exchanger Example

The direction in which the two fluids travel through the heat exchanger can be either parallel flow or counter flow.

Counter flow heat exchanger example.

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. In counter flow heat exchangers the fluids enter the exchanger from opposite ends. Consider a parallel flow or counterflow heat exchanger consisting of fluid 1 fluid 2 and the wall separating these two fluids. One starts off hot at 60 c the second cold at 20 c.

The simplest heat exchanger is one for which the hot and cold fluids move in the same or opposite directions in a concentric tube or double pipe construction. Crossflow parallel flow and counterflow heat exchanger configurations are three examples. Two tubes have a liquid flowing in the same direction. There are three primary classifications of heat exchangers according to their flow arrangement.

A thermoconductive membrane or an open section allows heat transfer between the two flows. A heat exchanger can have several different flow patterns. 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.

For a parallel flow heat exchanger n 0 and for a counterflow heat exchanger n 1. 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.