Optimization of heat transfer and heat-work conversion based on generalized heat transfer law

Abstract

Examples of heat transfer and heat-work conversion are optimized with entropy generation and entransy loss, respectively based on the generalized heat transfer law in this paper. The applicability of entropy generation and entransy loss evaluation in these optimization problems is analyzed and discussed. The results show that the entransy loss rate reduces to the entransy dissipation rate in heat transfer processes, and that the entransy loss evaluation is effective for heat transfer optimization. However, the maximum heat transfer rate does not correspond to the minimum entropy generation rate with prescribed heat transfer temperature difference, which indicates that the entropy generation minimization is not always appropriate to heat transfer optimization. For heat-work conversion processes, the maximum entransy loss rate and the minimum entropy generation rate both correspond to the maximum output power, and they are both appropriate to the optimization of the heat-work conversion processes discussed in this paper.