Experimental investigation on low-temperature thermal energy driven steam ejector refrigeration system for cooling application

In recent years, ejector refrigeration has been a hot topic for research because it can utilize low-grade energy such as solar energy or industrial waste heat. Even more importantly, it uses the most environmentally friendly substance, water, as the working fluid. According to the literatures, the utilization of the thermal energy from a low-temperature heat source below 80 °C is a considerable challenge for the steam ejector refrigeration system. In this paper, an experimental prototype of the steam ejector refrigeration system was designed and built up. Three ejectors with a same nozzle for the primary nozzle and three different constant-area sections were designed and fabricated. The effects of the operating temperatures, the nozzle exit position (NXP) and the area ratio of the ejector (AR) on the working performance of the steam ejector were investigated. The generating temperature is ranged from 40 °C to 70 °C. The experimental results show that a steam ejector can operate successfully for a certain configuration size of the steam ejector with a generating temperature ranging from 40 °C to 70 °C and an evaporating temperature of 15 °C. The results of this investigation provided a better understanding for the cooling application of the steam ejector refrigeration system powered by low-temperature heat source. It demonstrates that the steam ejector refrigeration system is a very promising alternative to the absorption refrigeration system, when the heat source temperature is lower than 80 °C.