新型整流喷嘴式分流器最佳入口工况数值模拟

目的:改善或尽可能消除制冷系统中节流后气液两相制冷剂在蒸发器中分配不均匀导致的制冷系统性能下降的现象。方法:基于多相流模型中的混合物模型,建立整流喷嘴式分流器的物理模型及气液两相流动的数学模型,通过CFD模拟该分流器内部的相分布情况和气液两相分离程度,分析入口工况(流速、干度)对分流器分液均匀性的影响。结果:当入口流速为1 m/s,入口干度为0.2时,流型逐步趋于稳定,形成对称的环形流,分流器在此工况下整体不均匀度达到最小值,分流效果最优。结论:在对分流器结构进行优化的基础上,通过调整入口工况至最佳可进一步优化流型,形成对称环形流实现均匀分液。

umerical simulation study of optimal inlet conditions of rectifier nozzle type distributor

Objective:In order to effectively improve or eliminate as much as possible in the refrigeration system, the uneven distribution of gas-liquid two-phase refrigerant in the evaporator leads to the performance decline of the refrigeration system. Methods:The adopts CFD numerical simulation method was used to establish the physical model of rectifier nozzle type distributor and mathematical model of gas-liquid two-phase flow, based on the mixture model in multiphase flow model, which simulated the phase distribution and the degree of gas-liquid two-phase separation inside this distributor,. Then the influence of inlet conditions (inlet flow rate and mass flow fraction of gas) on the uniformity of diverter distribution was analyzed. Results:The results showed that when the inlet flow rate was 1 m/s and the mass flow fraction of gas was 0.2, the flow pattern gradually stabilizes and a uniform annular flow could be formed. Under the control of these conditions, the overall unevenness of the distributor reached the minimum value and had the best effect of liquid separation. Conclusion:On the basis of optimizing the structure of the distributor, the flow pattern can be further adjusted by adjusting the inlet condition to the best, and the symmetrical annular flow can be formed to realize uniform liquid separation.