Entropy generation analysis on heat transfer characteristics of Twisted corrugated spiral heat exchanger utilized in solar pond

Abstract

In the present study, heat transfer and entropy generation in the spiral corrugated heat exchanger used in the solar pond have been numerically studied. The thermal boundary condition of the third type has been selected for simulation and different geometric parameters have been studied to improve heat transfer and reduce entropy generation. New correlations based on experimental data have been used to validate the simulation. The results were obtained by changing the parameters such as the number of corrugations, the twist number of the corrugations, and the change of the Reynolds number. Also, dimensionless parameters have been defined to investigate the increase of heat transfer and decrease of entropy generation based on the first and second laws of thermodynamics, and finally, the optimal geometries have been introduced by the NH multi-criteria parameter. The simulation results showed that the corrugation creation on the tube will increase heat transfer and decrease entropy generation. Therefore, it was found that the twist number of the corrugation has a greater effect than the number of corrugations. In the best case, when the number of corrugations and their twist is high, the heat transfer improvement number (NH) can grow up to 89%, which will decrease with the increase of Reynolds number.