R245fa作为替代CFC的新型工质,在高温热泵,低温发电系统等工程领域中有着广泛的使用。为满足仿真计算的需要,提出一种基于MH81方程的R245fa物性计算模型。该模型在过热区符合良好,在过冷区修正为六参数的拟合式之后,其精度与过热区相当。将计算式与物性数据进行对比,结果表明平均相对误差小于8%,最大相对误差小于13%。 R245fa CFC as a new alternative to the working fluid in the high-temperature heat pump, low-temperature power generation systems and other engineering fields have a wide range of use. In order to meet the need of simulation calculation, a kind of R245fa physical calculation model based on MH81 equation is proposed. The model fits well in the overheat zone, and its accuracy is comparable to that in the overheated zone after the subcooling zone is corrected to a six-parameter fit. Comparing the formula with the physical data, the results show that the average relative error is less than 8% and the maximum relative error is less than 13%.