【摘要】 毛细管作为家用空调器、电冰箱的节流元件,因为不能随制冷系统负荷变化而调节流量,所以设计毛细管合理参数至关重要。今将整个毛细管内的流动分为过冷液体区和气液两相区两个过程,建立了毛细管内制冷剂两相流动的漂移流模型;这一模型考虑了各相平均速度之间的差异,克服了以往均相流动模型的缺点。进一步考虑两相间相对运动和空隙率及流速沿截面的分布规律,对毛细管长度进行了数值计算。编制了毛细管长度计算的应用程序,并将数值计算结果与文献中的实验数据进行了分析比较,其误差在工程设计的允许范围之内。更多还原

【Abstract】 As the throttle elements for air conditioners and refrigerators, the capillary tubes cant regulate the flux when the load of refrigerative systems is varying; therefore, it is quite important to design the proper parameters for the capillary tubes. For this reason, the refrigerant flow in whole capillary tubes is meticulously divided into two parts: one is the overcooled liquid flow, the other is the two-phase flow for which a drift flux model is presented. This model takes into account the difference of average velocities between gas-phase and liquid-phase, which overcomes the defect of mean-phase flow model. Based upon this model, the length of capillary tubes was calculated considering the two phases relative motion and the distribution of void fraction and phases velocities along the tube section. A computer program was also made for calculating the length of capillary tubes. The comparison of the calculated results with the corresponding experimental results shows that the differences between two results are less that 5% which satisfies the engineering requirement.更多还原