覆盖亚临界到临界区的制冷工质物性快速算法

FAST CALCULATION METHOD FOR THERMODYNAMIC PROPERTIES OF SUB-CRITICAL AND CRITICAL REFRIGERANT

为了在亚临界到临界点这个大范围内保证制冷剂物性计算的快速、稳定、可逆,提出将整个数据区间划分成若干个子区间分别进行隐式拟合,并且保证相邻子区间连接点处的连续与光滑,以及通过求分析解从隐式方程中得到显式物性计算式的方法。以美国国家标准局开发的程序REFPROP6.01的计算结果作为数据源,以R410A为例对该方法做了验证。得出快速物性计算公式的应用范围为饱和温度-60℃至临界温度,与NIST REFPROP 6.01的计算结果进行比较表明,计算速度快1500倍,平均相对偏差小于0.01%。

In order to obtain fast,stable and reversible calculation method of refrigerant thermody- namic properties in the wider range covering sub-critical and critical region,a method of dividing the whole data range into several subsections for separately implicit-regression and explicit-calculation is presented.The method guarantees the requirements on the continuity of thermodynamic properties and the 1st order derivative of thermodynamic properties in the intersection points of subsections.Case studies have been carried by regressing the saturation thermal properties of R410A in a data range of saturation temperature from -60℃to the critical temperature.The source data are calculated from REFPRO 6.01.The comparison result shows that calculation speed of the fast calculation formulae is 1500 times faster than those of REFPRO 6.01,the mean relative deviations of the fast calculation formulae are within 0.01%.