排气管内置深度对气-液旋流分离器流动特性的影响

Effect of Exhaust Pipe Insertion Depth on the Flow Behaviors of Gas-Liquid Cyclone Separators

排气管在具有二级旋流分离机制的分离器中至关重要。模拟分析了排气管内置深度对气-液旋流分离器流动不稳定性、旋流场、短路流以及径向流量分布的影响。研究表明,增加排气管内置深度可更好地引导旋流,提高流场稳定性;随内置深度增加,分离空间准自由涡出现衰减,准强制涡强度增大,下行与上行轴向速度均减小,在排气管中形成一定强度的旋流,有助于实现二级分离功能;同时,分离器环形空间预分离能力增强,短路流量增加,单位长度零轴速包络面上的径向流量增加,排气管的二级分离功能有助于削弱短路流带来的负面影响。

The exhaust pipe is essential to the study of the separator which has two-stage cyclone separation mechanism. The Reynolds Stress Model was used to simulate the effect of exhaust pipe insertion depth on rotational flow instability, swirling flow field , short-circuit flow and radial flow of the gas-liquid cyclone separator. The results show that the increase of exhaust pipe insertion depth helps to strengthen guidance and control for inner rotational flow , and can enhance rotational flow instability. With the increase of exhaust pipe insertion depth, quasi-free vortex in the separated space is damped, the intensity of quasi-forced vortex is enhanced, and both the downward and upward axial velocities are decreased. Certain intensive rotational flow still appears in the exhaust pipe, which helps to achieve two-stage separation mechanism. Meanwhile, the pre-separation capability of separator annular space improves, short-circuit flow aggravates, and rotational flux inperunit length of zero axial velocity surface increases. The two-stage separation mechanism of the exhaust pipe can help to weaken the negative effects caused by the short-circuit flow.