Evaluation of the impact of the temperature and mass flow rate of the water, utilized in the R516A refrigeration system with dual evaporator and ejector, on the performance parameters

Abstract

ABSTRACT The refrigeration system can be utilized with dual or multi-evaporator to meet the cooling needs at several vapor pressures with a single compressor refrigeration system. The evaporators utilized in these systems can take water or air to the desired low temperatures. The energy consumption of the compressor can be decreased and the system can be made more efficient by including an ejector in refrigeration systems with dual evaporator. Within the scope of this study, an experimental refrigeration system with an ejector and two evaporators, the first one (evaporator#1) sourced by air, and the second one (evaporator#2) sourced by water, were installed. The performance of the experimental dual-evaporator ejector system (DEES) was tested depending on the water temperature and mass flow rates passing through evaporator#2. The performance parameters of the system at several mass flow rates and water temperature were analyzed, and the ejector’s impact on the system was determined. As a refrigerant in DEES, low GWP (global warming potential) R516A refrigerant was utilized. System performance was calculated for three different water mass flow rate values at several water temperatures passing through evaporator#2. As a result, it was determined that when the water temperature increased from 10°C to 30°C and the water mass flow rate was the maximum, the power of the compressor increases by 7.2%, while the total refrigeration capacity rises by 25.9%. The results showed that the coefficient of performance (COP) increased by 9.1%, 15.2%, and 16.5%, respectively, at m1, m2, and m3 mass flow rates with the increase in water temperature from 10°C to 30°C. Additionally, evaporation temperatures in the evaporator increased with the decrease of entrainment ratio (ER). Finally, it was determined that the impact of the change in ER values on the superheating degree temperatures was higher than the mass water flow rate values.