A novel two-stage ejector refrigerator with mixed refrigerants

Abstract

The energy consumption is ramping up in recent decades. Therefore, it was very important to recover and utilize the low-grade energy, such as the solar energy, the geothermal energy and low-temperature waste heat discharged to the environment. The ejector system has a good prospect in this area due to its obvious advantages :simple structure, without moving part and available for heat sources in different temperature levels, as well as long life-span. Nevertheless, the coefficient of performance of the ejector system is relatively low, so the technology to optimize the ejector refrigeration cycle has been hot topics. In this report, a novel two-stage ejector system with mixed refrigerants was proposed to improve the efficiency of the ejector system. A separator was used to divide the working fluid to high boiling point fluid and low boiling point fluid. The performance of the new system was calculated and compared with other ejector systems. It was suggested that the novel system had a higher COP than other ejector refrigeration systems. Furthermore, it could operate at a higher condensation temperature. When the condensation temperature continued to rise above 50℃, the new system could still be reliable and the COP was about 0.1