Entropy Parameters for Heat Exchangers Design

A general expression for the entropy generation in counter current heat exchangers is developed. It is applicable to incompressible liquids and perfect gases. Two new entropy generation numbers are defined, NM and NQ. The analysis is applied to an air-air counter current heat exchanger. The three entropy generation numbers, NS, NM and NQ, have a different variation with NTU at the various values of the capacity flow rates ratio employed in the calculations.