制冷剂饱和热力性质的隐式拟合方法

１前言准确、快速、稳定地计算制冷剂热力性质是计算机辅助设计和工程计算的要求。但目前流行的多项式类简化拟合函数在总体计算精度、外推以及求反计算等方面都有待改进［１－３］。本文从函数展开的角度剖析了现有多项式类拟合函数的不足，提出了一种低次的隐函数形式的...

AN IMPLICIT CURVE-FITTING METHOD FORREFRIGERANT THERMODYNAMICSATURATION PROPERTIES

Fast calculation of the refrigerant thermodynamic properties is fundamental and important for engineering calculations, especially for the refrigeration system simulation. But thepublished models for the thermodynamic properties evaluation are not suitable because oftheir complexity form or limited available range. In this work, a new polynomial curve-fittingmethod is developed to meet the requirements of fast evaluation of the refrigerant thermodynamic properties for the refrigeration system simulation. An implicit cubic linear function isadopted for the curve-fitting of the refrigerant saturation properties and a sectional smoothtechnique is developed for a wider fitting range. Case studies using refrigerants R12, R22,R134a and R600a, in common encountered temperature range show high agreement to thereference data and good flexibility in the refrigeration system simulation.