带膨胀机的HFC134a与HFO1234yf制冷系统分析

对带膨胀机的R134a与R1234yf制冷系统进行理论分析,并与不带膨胀机的系统进行比较。研究表明:HFC134a的排气温度明显高于HFO1234yf,HFC134a的排气温度随着蒸发温度的升高而降低,HFO1234yf的排气温度随着蒸发温度的升高而升高;HFC134a与HFO1234yf的单位制冷量都是随着蒸发温度的升高而增大,但HFC134a的单位制冷量明显高于HFO1234yf,其平均高于HFO1234yf约34.9kW/kg;HFO1234yf压缩机输入功率明显高于HFC134a,HFC134a的系统COP高于HFO1234yf的系统COP,且二者都是随着蒸发温度的升高而升高。在制冷系统中加入膨胀机后,对HFC134a产生了显著的影响,在蒸发温度-10℃时变化最为明显,其单位制冷量增大32%,压缩机输入功率降低12.1%,系统COP降低19.8%,膨胀机的加入并没有影响HFO1234yf系统,其各项参数均未发生明显变化。在HFO1234yf制冷系统中应用膨胀机的效果逊于HFC134a制冷系统。

Application analysis of refrigerant HFC134a and HFO1234yf in refrigeration system with expender

A theory simulation of operation performance about HFC134a and HFO1234yf in refrigeration system with expender was presented.The results show that the discharge temperature of HFC134a is higher than the discharge temperature of HFO1234yf,but the change trend with the evaporation temperature is different.The discharge temperature of HFC134a reduces with the rising of evaporation temperature and the discharge temperature of HFO1234yf increases with the rising of evaporation temperature.The unit capacity of HFC134a and HFO1234yf rise with the rising of evaporation temperature and the unit capacity of HFC134a is average higher than that of HFO1234yf in 34.9kW/kg.The input power of HFO1234yf is higher than that of HFC134a.The COP of HFC134a is higher than that of HFO1234y and the two refrigerants’ COP increase with the rising of evaporation temperature.The application of expender produces obviously influence in HFC134a,when the evaporation temperature-10℃,the cooling capacity increases 32%,the input power decreases 12.1% and the COP decreases 19.8%.The situation of HFO1234yf is different,all parameters of it is no change.So it can conclude that the application of the expander of HFO1234yf refrigeration system is almost no effect comparing with that of HFC134a.