Entropy generation analysis and performance evaluation of heat transfer enhancement through internal flow

An analytical method based on the entropy generation theorem for fluid flow and heat transfer process was developed with the assumption of fully developed flow and constant wall temperature, and the method was used to obtain dimensionless entropy generation number, and performance evaluation criteria (PEC) of heat transfer enhancement were obtained with the constraints of identical mass flow, pump power and pressure drop respectively under fixed heat duty. The applications of these treatments were illustrated by the analysis of heat transfer and fluid friction characteristics of internally finned tubes from literature data. It was shown that the dimensionless entropy generation number depended exclusively on Reynolds number and wall-to-inlet temperature difference for a given duct or tube, and the method might help to identify inappropriate enhanced tubes or extended surfaces and assist engineers to design better heat transfer equipment with the criteria assessing the merits of augmentation techniques in connection with energy conservation and exergy destruction according to entropy generation analysis.