适用于宽温度和压力范围的湿空气热力性质分段计算方法

Segment Calculation of Thermodynamic Properties for Moist Air in Wide Range of Temperature and Pressure

根据计算范围的不同,提出适合宽温度、压力范围,涵盖多个湿空气热物理性质参数的分段计算方法:在低温、低压范围内将湿空气看作理想混合气体,采用理想气体状态方程建立模型计算湿空气的热物理性质参数;在高温、高压范围内将湿空气看作干空气和水蒸气的实际二元混合气体,采用维里方程建立湿空气的半经验模型计算湿空气的热物理性质参数.分析确定了分段计算的分界点,并说明了分段计算的连续性.结果表明:与参考文献的计算结果相比,采用该文提出的湿空气热力性质分段方法得出的计算结果的最大误差仅为4.5%,且计算过程简单快捷,易于程序实现,可用于绘制焓湿图.

A segment calculation method is being presented for thermodynamic parameters of moist air in wide range of temperature and pressure.At relatively low temperature and pressure,the moist air is considered as ideal mixed gas,and its thermodynamic properties are calculated with models based on ideal gas equations;whereas,at relatively high temperature and pressure,the moist air is considered as a mixture of dry air and water vapor,and its thermodynamic properties are calculated with semi-empirical models based on Virial state equations.The demarcation point of segment calculation has been analyzed and determined,while the continuity demonstrated.Results show that compared with some reference data,the maximum error of calculated results obtained by above segment method is only 4.5%,and the calculation process is found to be fast and facile,which may therefore be used to draw relevant psychrometric charts.