The performance comparison of the OTEC cycles with an ejector

Abstract

To address the low efficiency of Ocean Thermal Energy Conversion (OTEC), cycles with applied ejectors were studied. The high-pressure working fluid from the motive part of an ejector passing the suction part lets in low-pressure fluid and the combined fluid comes out of the discharge part, lowering the pressure of the suction part. The pressure difference between the inlet and outlet of the turbine becomes bigger than a basic cycle, which leads to higher efficiency under the same flow rate. The performances of three OTEC cycles with applied ejectors were analyzed and compared in this study. The cycles that were used for analysis were a vapor-vapor ejector cycle with an R32 refrigerant, a liquid-vapor ejector cycle with an R32/R152a mixed refrigerant, and a liquid-vapor ejector cycle with an R152a refrigerant using a motive pump. The temperature of the heat source was 26°C, and that of the heat sink was 5°C. For 20 kW power generation, the performances of each system, such as the flow rate and efficiency, were compared and studied. ？ 2016 Taylor & Francis Group, London.