泵腔内部环流对射流式自吸泵自吸性能的影响

为了研究自吸泵内部气液两相流动情况,选取JETST-100型射流式自吸泵作为研究对象,运用CFX软件提供的欧拉—欧拉多相流模型,对导叶背面添加防止环流筋板后的泵腔内气液混合及气液分离情况进行了三维非定常数值模拟,得到了各过流部件压力和速度分布等内部流动信息,分析了射流器进口和泵腔出口处各监测点气相体积分数的变化情况,并将模拟结果与试验进行对比。结果表明:液体从导叶出流后,会形成一个较大的速度环量,导致气液分离不充分,大量液体进入出水管路,泵腔内液体减少;在导叶背面添加筋板后,射流器进口处气相体积分数减小,喷嘴出流的工作液体中夹杂的气相体积分数减小,泵腔出口气相体积分数增大,从而提高了自吸性能。

Effects of Internal Circulation Flow on Self-priming Performance of Flow-ejecting Self-priming Pump

In order to study the gas-liquid two-phase flow during the gas-liquid mixing and separating process, a flow-ejecting self-priming pump named JETST-100 was chosed. Based on Eulerian-Eulerian multiphase flow model, the transient numerical simulation of the gas-liquid mixing and separating phenomena on the pump chamber was carried out using CFX software. The distributions of pressure, velocity and gas-liquid phases field inside the pump were obtained, and the change of the air volume fraction by monitoring the points on the gas-liquid separation chamber outlet and jet aerator inlet were analyzed . The test and simulation results show that the flow of liquid from the guide vane formed a large amount of velocity circulation. And the water of the pump chamber reduced with the large amount of water into the outlet channel. It was found that adding the reinforcing plate could prevent the generation of circulation on guide vane back, and improve the self-priming performance of the pump.