利用精确度高的P-R状态方程和M-H81状态方程,采用余函数法对制冷剂的比定压热容进行了理论推算和比较分析。文中选用了10种纯制冷剂和4种混合制冷剂进行了详细的计算和比较,计算结果表明:在气相区,2个状态方程模型的计算精度均在3%左右;在液相区,M-H81型方程模型明显优于P-R方程,其计算精度在10%以内。M-H81型方程模型比P-R方程优越,能更好地预测更宽广温度和压力范围的流体比定压热容。文中的工作初步验证了利用状态方程推算实际流体比定压热容的可行性,为其他基础物性的理论预测提供了坚实的理论思路。
Based on P-R equation of state and M-H81 equation of state with high accuracy,detailed calculation and analysis were made by utilizing residual function method.10 pure refrigerants and 4 mixing refrigerants were chosen and compared with experimental results.The calculation results show that in vapor-phase region,the estimation precision is about 3% for both models;while in liquidphase region,M-H81 EOS model is better than P-R EOS model with an estimation precision of less than 10%.M-H81 equation model is more appropriate than P-R equation model to make precise calculation within a broader temperature and pressure range.The study validates the feasibility of theoretical method,and can be a guideline for further study on other basic thermophysical properties.