Numerical analysis of an ejector in refrigeration applications using various refrigerants

In this paper, the performance of an ejector in a refrigeration system has been numerically studied using different refrigerants. The R134a refrigerant, with good thermodynamic properties, has relatively high geothermal impact. Consequently, six other environment-friendly refrigerants including R152a, R600, R600a, R1234ze, R1234yf and R290 have been replaced. Results show that the maximum value of entrainment ratio is obtained using R290, R600a and R600 refrigerants respectively. In addition, the effect of operating temperatures (related to the boiler and evaporator) on ejector performance is evaluated using R134a. Results show that enhancement of the boiler temperature has an adverse effect on ejector performance and reduces the entrainment ratio. In contrast, increasing of the evaporator temperature leads to the increment of the entrainment ratio.