Minimization of Entransy Dissipations of a Finned Shell and Tube Heat Exchanger

Improving heat transfer and performance in a radial, finned, shell and tube heat exchanger is studied in this study. According to the second law of thermodynamics, the most irreversibilities of convective heat transfer processes are due to fluid friction and heat transfer via finite temperature difference. Entransy dissipations are due to the irreversibilities of convective heat transfer. Therefore, the number of entransy dissipation is considered as the optimization objective. Thirteen optimization variables are considered, including the number of tubes, tube diameter, tube length, fin height, fin thickness, the number of fins per inch length of tube and baffle spacing ratio. The “Delaware modified” technique is used to determine heat transfer coefficients and the shell-side pressure drop. In this technique, the baffle cut is 20 percent. The results show that using genetic algorithm the optimization can improve the heat transfer by 13percent and performance of heat exchanger increased by 18percent. In order to show the accuracy of the algorithm the results compared to the particle swarm optimization.