INVESTIGATION OF THE SELF-PRIMING PROCESS OF SELF-PRIMING PUMP UNDER GAS-LIQUID TWO-PHASE CONDITION

The self-priming process of self-priming pump is gas liquid two-phase flow process with complex internal transient flow The effect of gas-liquid mixing and separating performances will play a crucial role during self-priming process. In order to study the self-priming process and improve the self-priming performance, the model named JETST-100 was selected. Based on Eulerian-Eulerian multiphase flow model, transient numerical simulation of the gas-liquid mixing and separating phenomena on the pump chamber was carried out by using CFX software. The distributions of velocity vector, contours of gas volume fraction and liquid velocity of the pump or jet aerator, and the change of the gas volume fraction by monitoring points on the jet aerator were obtained. Test and simulation results show that the gas-liquid two-phase flow from the guide vane will form a larger velocity circulation, so that the gas-liquid separation is not sufficient. And the volume fraction of liquid inside pump chamber decrease with a large amount of water enters the outlet pipe. It is found that adding the baffle plate can prevent the generation of circulation on guide vane back, the gas-phase volume fraction of jet aerator inlet and nozzle outlet decreases, improve the self-priming performance of the pump.