An alternative analysis applied to investigate the ejector performance used in R141b jet-pump refrigeration system

•The ejector performance of a jet-pump refrigerator was analysed based on an alternative analysis.•A parameter called “Critical evaporator temperature” was determined.•The critical point varies with the change in operating conditions and primary nozzle used.•The optimum range of the primary mass flow rate was determined experimentally.

The system performance of R141b jet-pump refrigerator is discussed based on an alternative analysis. It explains the operation of the jet-pump refrigerator operating under actual conditions. A 2 kW cooling of R141b jet-pump refrigerator is designed and constructed to test the ejector performance. With the use of an alternative analysis, point of interest called “critical evaporator temperature” is determined. This point indicates the lowest possible evaporator temperature where the secondary fluid flow is still choked. The critical point varies with the change in operating conditions and with the primary nozzle used. An increase of primary mass flow rate causes the critical point reducing. However, it does not always true. When the primary mass flow rate increases to a certain value, the refrigerator is operated at higher critical evaporator temperature. Thus, the optimum range of the primary mass flow rate for this particular ejector is provided for this present work.