绝热毛细管中制冷剂流动特性的一阶积分模型

制冷剂在绝热毛细管内的流动因存在汽液两相流而较为复杂．本通过引入两相流区压力和比容之间的一阶近似式，获得该问题的一阶近似积分解．在常见的制冷空调工况范围内，以制冷剂CFC-12、HFC-134a和HC-600a为工质，对该模型与分布参数模型进行了对比；同时也与实验数据进行了对比．结果表明：与分布参数模型的平均偏差小于1％，与实验数据亦较好吻合；计算速度较分布参数模型提高了一个数量级以上。

One-order Integral Model of Refrigerants Flowing Through Adiabatic Capillary Tubes

Two phase flow in adiabatic capillary tubes is generally described by partial differential equations and solved with finite difference method. In the work, an one order approximant for the mapping between the pressure and the specific volume in two phase regime was presented by Taylor series expansion. As a result, an one order approximate integral solution to the flow performance of adiabatic capillary tubes was obtained. The new model was compared with the distributed parameter model under the common working conditions of refrigeration and air conditioning. Three refrigerants CFC 12, HFC 134a and HC 600a are used as working fluids. The average deviations between the new model and the distributed parameter one falls into 1%. The computation speed of the new model is more than one order of magnitude higher than that of the distributed parameter one. In addition, the new model was used to predict the experimental mass flow rates through adiabatic capillary tubes. The consistency between the calculated values and the experimental ones is also satisfactory.