超音速喷嘴涡流管气体分离性能的数值模拟与实验

Simulation and Experiment on Gas Separation Performance of a Vortex Tube With Supersonic Inlet Nozzles

建立了超音速喷嘴涡流管的简化几何模型,利用描述两相双组分超音速冷凝流动的Eulerian双流体三维湍流模型,以含湿空气为介质对装置内部的自发凝结过程进行数值模拟。设计制造相应的装置,建立实验平台,对装置的含湿气体分离性能进行实验研究。通过模拟和实验2种手段研究了影响超音速喷嘴涡流管气体分离性能的参数及其影响规律。结果表明,气流在喷嘴内部达到超音速流动,使得水蒸气自发凝结成液滴,为混合气体分离提供了先决条件;热端管内气体自旋产生的离心加速度可以达到重力加速度的6×105倍,为气、液分离提供了必要条件;降低进出口压力之比和冷流率,增大入口相对湿度和长径比可以提高装置的气体分离性能,安装阻涡器对性能有不利影响。因此,采用超音速喷嘴涡流管实现混合气体中重组分的脱除是可行的。

A simplified geometrical model for the vortex tube with supersonic inlet nozzles was set up.A three-dimensional turbulent model for the bi-component two-phase supersonic condensing flow was adopted to simulate the spontaneous condensation in the device with moist air as medium.A device of the same dimension and structure as the simplified geometrical model was designed and manufactured.Combining with the assistant equipments and measure systems,an experimental platform for the investigation of the gas separation performance of vortex tube with supersonic inlet nozzles was built.The effecting factors and their influences were discussed based on the simulated and experimental results.The simulated results indicated that the gas flow could achieve the supersonic state in inlet nozzles,leading to the spontaneous condensation of water vapor.The formation of water droplets made the gas mixture separation become possible.Besides,the centrifugal acceleration of self-rotational gas flow in the hot tube could approach to 6×105 times as large as acceleration of gravity,which was propitious to the separation of gas and formed droplets.Thus,it was feasible to separate heavy component from gas mixture by vortex tube with supersonic inlet nozzles.Decreasing the inlet-outlet pressure ratio and cold flow rate,and increasing the inlet relative humidity and the length diameter ratio of hot tube could improve the gas mixture separation performance of device.The setting of rectifier had bad influence on the gas mixture separation performance.