湿空气饱和水蒸汽曲线计算模型的建立与分析

Calculation modeling of the water vapor saturation curve of moist air and its analysis

湿空气物性的高精度计算中,饱和水蒸汽曲线的计算建模是关键所在。在对已有的饱和水蒸汽压力公式进行误差分析比较后,得到了Gerry方程误差最小的结论。为解决计算的连续性问题,重新界定了该方程中冰面及水面方程的分界点。其次,建立了两种高精度的t-p公式,可方便直接的计算湿空气露点温度。最后,分析了饱和蒸汽曲线斜率的意义,推导出它的计算式。以上建立的湿空气饱和水蒸汽曲线计算模型,不仅具有快速方便的物性计算功能,还提供了准确判定湿空气状态变化的准则。

In high - precision calculating moist air properties, calculation model of the water vapor saturation curve of moist air is the key. This paper compared errors of different formulas of the water vapor saturation pressure which were already presen- ted, and the error of Gerry equation was the least. For the accuracy and continuity of the model, the dividing point between Gerry ice equation and liquid equation was redefined. Then, two types of rigorous t - p formulas were developed for computing dew ：. point temperature. Finally, the significance of the slope of the saturation curve was analyzed, and the slope＇s formula is derived. The calculation model established above could not only calculate moist air properties quickly and accurately, but also provide a formulation discriminating state change processes of moist air.