Ocean thermal energy conversion (OTEC) generates electricity through a heat engine by exploiting the temperature difference between the ocean surface and deep seawater. Since the effective temperature difference for the heat engine depends on the heat exchangers’ performance, the irreversible loss in the heat exchangers should be reduced. However, heat exchangers with high heat transfer performance generally have a large pressure drop, and the finite heat transfer performance and the fluid flow resistance cause irreversible loss during the heat transfer process. Performance evaluation methods for heat exchangers generally evaluate the heat transfer performance and pressure drop separately. The objective of this study was to develop a performance evaluation method that could be used for maximizing the net power of OTEC based on finite-time thermodynamics (FTT). On the basis of the FTT model, the relationship between a heat exchanger’s performance for an irreversible heat engine and the net power output per heat transfer area is presented. Additionally, a comprehensive performance index for the heat exchanger is proposed. The performance evaluation procedure and the comparison of the plate heat exchanger performance are conducted to show the effectiveness of the performance evaluation method. The results show that the proposed evaluation method presents the beak down of the performance ratio of heat exchangers, which indicates the quantitative performance for every heat exchanger in terms of the maximum net power generation of OTEC.      «

Ocean thermal energy conversion (OTEC) generates electricity through a heat engine by exploiting the temperature difference between the ocean surface and deep seawater. Since the effective temperature difference for the heat engine depends on the heat exchangers’ performance, the irreversible loss in the heat exchangers should be reduced. However, heat exchangers with high heat transfer performance generally have a large pressure drop, and the finite heat transfer performance and the fluid flow...     »