초록
In this paper, the performance characteristics of an ejector-expansion refrigeration cycle (EERC) using R410A are investigated in comparison with that using R22 based on first- and second-law perspectives. For this purpose, a numerical model of constant mixing pressure is developed and a parametric study of the effective design parameters is implemented. The results show that at evaporation temperature (Te) and condensing temperature (Tc) equal to 5∘C and 40∘C, respectively, the coefficient of performance (COP), exergy efficiency and volumetric cooling capacity (VCC) of the R410A EERC is improved by 12.91%, 12.89%, and 10.8%, respectively. Compared with the conventional refrigeration cycle, the EERC is more beneficial at lower evaporation temperature and higher condensing temperature. The COP of R410A EERC, exergy efficiency and VCC improvements over the regular refrigeration cycle are also greater than that of R22 by about 34.7%, 32.3% and 31%, respectively. Exergy analysis shows that applying an ejector in lieu of a throttle valve improved the energetic efficiency by 7.793–15.42% and by 10.59–22.79% for R22 and R410A, respectively, for the given range of evaporating and condensing temperature. In addition, the effects of the suction nozzle pressure drop, area ratio and the component efficiencies of the ejector on the EERC performance are analyzed.
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