并联管路气液两相流分流实验与数值模拟

为了研究气液两相流在并联立管中的分流状况，在实验室中建立了带有并联立管的气液两相流流动回路。建立了气液两相流分流数学模型，通过数值模拟方法对气液两相流分流进行研究。实验过程中发现了并联立管中三种不同的流动状态分别为弹状流-弹状流、搅混流-搅混流以及弹状流-搅混流。实验结果表明当并联立管中的流动状态为弹状流-弹状流时，两根立管中的压降相同，但是并联立管中的液塞排出并不具有同步性，可能产生偏流状况。在气液流速较高的搅混流-搅混流时两相流在并联立管中始终处于均匀分配状态。介于两者之间的弹状流-搅混流，并联立管中的压降产生较大的偏差，气液两相流流量更倾向于搅混流一侧流出，此时并联立管中产生严重的偏流状况。数值模拟过程中，通过对并联立管出口持液率进行监测，在较低的气液速下两相流并不能够均匀分配，但是在较高的气液速下，两相流始终处于均匀分配，可见所建立的数学模型具有良好的准确性。

Experimental and numerical simulation of gas-liquid two-phase flow splitting in parallel risers

In order to study the distribution of gas-liquid two-phase flow in parallel risers, a gas-liquid two-phase flow loop with parallel risers was established in the laboratory. Established a mathematical model of gas-liquid two-phase flow splitting, the splitting characteristics of gas-liquid two-phase flow is studied by numerical simulation method. During the experiment, three different flow states in the parallel riser were found: slug flow-slug flow, churn flow-churn flow and slug flow-churn flow. The experimental results show that when the flow state in the parallel risers are slug-slug flow, the pressure drop in the two risers are the same, but the discharge of the liquid plug in the parallel risers are not synchronized, and the two-phase may be unevenly distributed. When the gas-liquid velocity is high enough to maintain churn-churn flow in the parallel risers, the two-phase flow is always evenly distributed in the parallel risers. The pressure drop of slug-churn flow which between the two flow states in the parallel risers had a large deviation, and the flow of gas-liquid two-phase flow tends to flow out from the side of churn flow, in this case two-phase splitting unevenly in the parallel risers. In the process of numerical simulation, by monitoring the liquid holdup at the outlet of the parallel risers, the two-phase flow can not be evenly distributed at a lower gas-liquid velocity, but at a higher gas-liquid velocity, the two-phase flow were always evenly distributed, which shows that the established mathematical model has good accuracy.