An experimental investigation to determine the optimal heat source temperature for R141b ejector operation in refrigeration cycle

This paper provides an experimental investigation of an R141b ejector refrigeration system which concentrates on the effect of the driving generator temperature on the ejector performance under various working conditions. The experimental ejector refrigerator working with R141b was designed and built for investigation. The generator temperature was varied to determine the optimal generator temperature. The working generator temperature was varied between 80 and 105 degrees C. The evaporator temperature was ranged from 6 to 14 degrees C. Three primary nozzles were used to investigate the effect of the ejector area ratio to the optimal performance. The condenser saturation temperature was ranged from 28 to 34 degrees C. It was found that the optimal generator temperature varied with the change in the working conditions and primary nozzle used. With variation in the evaporator temperature, the upstream pressure ratio was initially introduced and its impact on the optimal operation was later discussed. This upstream pressure ratio strongly influenced the optimal operation at relatively high evaporator temperature, and hence, the proper value was determined for this present work. In addition, the proper ejector area ratio for working condition consistent with this present work was determined. The results also demonstrated the feasibility of using an ejector refrigerator with a relatively low generator temperature while rejecting unwanted heat at relatively high condensation temperature.