Abstract: This paper analyzes the saturated pressure, and refrigeration capacity per unit volume of R290(propane) and R600a(isobutene) mixture with different mixing ratios, on the basis of thermodynamic properties of hydrocarbons.Compared with R134a, R290/R600a mixture with the ratio of 60%/40% is the best to replace R134a.Refrigeration performances of R134a and R290/R600a mixture were tested in a bus air conditioner.The results showed that performance of refrigeration coefficient and refrigeration capacity of R290/R600a(60%/40%) blend were about 2% and 10% higher respectively, than those of R134a.R290/R600a（60％/40％）can be a substitute refrigerant to replace R134a in car air conditioners.

摘要： 在HCs制冷剂热物性分析的基础上，对不同比例的R290（丙烷）和R600a（异丁烷）混合物的饱和蒸气压、单位容积制冷量进行了分析，并与R134a进行了比较，找出了R290和R600a混合物替代R134a的最佳混合比约为（R290/R600a）60％/40％.并在一台巴士汽车空调上对R290/R600a（60％/40％）和R134a的制冷性能进行了测试，结果表明：R290/R600a（60％/40％）的制冷系数约比R134a高约2％，制冷量比R134a高约10％.从制冷性能上，R290/R600a（60％/40％）可以作为R134a在汽车空调上的直接替代工质.