The Performance Comparison of the OTEC Cycles with an Ejector

Abstract

In this study, the ejector was applied to the ocean thermal energy conversion (OTEC) cycle performance for its performance improvement. The vapor-vapor ejector, liquid-vapor ejector, and liquid-vapor ejector with a motive pump were appliedto OTEC. Ejectors were classified into the vapor-vapor and liquid-vapor ejectors according to the phase of the fluid that entered the operative and intake parts. In this study, the OTEC cycles with the aforementioned ejectors were compared in view of their performances, and the results are as follows. In Korean condition, the OTEC cycle with a vapor-vapor ejector with R32/R152a mixed refrigerant had a 2.79% efficiency, which was 13.4% higher than the basic OTEC cycle efficiency, 2.46%. The OTEC cycle with a liquid-vapor ejector with R32/R152a mixed refrigerant had a 2.65% efficiency, which was 7.7% higher than that of the basic OTEC cycle with the same refrigerant. In the OTEC cycle with a liquid-vapor ejector with R32/R152a and a motive pump, when a 300 kPa boost was conducted by the motive pump, the generation efficiency was 3.43%, which was 39.4% higher than that of the basic OTEC cycle with R32/R152a.