丙烷和丙烯用于低温冷柜的性能和充灌量研究

Performance and Charge Analysis of Propane and Propylene Used in Low Temperature Cabinet Freezers

为了解决目前应用于低温冷柜的制冷剂R22、R404A等的环保问题,将天然工质HCs(碳氢化合物)应用于低温冷柜以替代上述传统的低温制冷剂.编写了制冷剂循环性能程序,比较了HCs和R22等在低温工况下的热力学循环性能.根据欧盟标准EN-378中对HCs充灌量的要求,建立了相应的冷柜充灌量计算模型,计算比较了R1270(丙烯)、R290(丙烷)和R22的理论充灌量.结果表明:R1270和R290的压力比、排气温度等比R22要低,系统的性能系数比R502、R507A、R404A要高,综合性能要好于R22、R502、R507A、R404A;R1270和R290在某冷柜中的最优充灌量分别为130 g和110 g,远小于R22的220 g,符合欧盟标准的安全要求.

The study was performed on the replacement of the refrigerants such as R22 and R404A with hydrocarbons （HCs） in low temperature cabinet freezers. The refrigerant cycle performances of HCs and R22, etc. under low-temperature conditions were compared via our computing program. According to the charge requirement of HCs in the EU standard EN-378, a theoretical charge model was established and the charge was calculated for R1270（propylene）, R290 （propane） and R22 in a cabinet freezer, respectively. The results show that the pressure ratio and discharge temperature of R1270 or R290 are lower than those of R22, and the coefficient of performance is higher than that of R502, RS07A or R404A. Moreover, the comprehensive performance of R1270 or R290 is better than that of R22, R502, R507A or R404A. In addition, the optimum charge of R1270 and R290 in a certain cabinet freezer is about 130 g and 110 g, respectively, far less than 220 g of R22.