泡状入流条件下离心泵喘振特性试验研究

A centrifugal pump is designed to obtain the flow in the whole impeller channel. The surging characteristics of the centrifugal pump are investigated by employing the high-speed camera technology. The correlative mechanism between the gas and liquid distribution in the impeller and the pump surging is discussed; then the effects of the inlet gas volume fraction, the liquid flow rate and the rotating speed on the pump surging characteristics are analyzed. Finally, several typical pump surging prediction correlations to predict the critical gas volume rate are compared based on the present test data. The results show that the centrifugal pump surging is mainly affected by the gas-liquid two-phase distribution in the impeller. The pump surging occurs when flow pattern in impeller transforms from gas-pocket flow to separate flow. The increase of inlet gas volume fraction is directly responsible for the pump surging phenomenon by affecting the flow pattern in the impeller, thus affects the pump performance. Under the condition of surging of centrifugal pump, the surging can be alleviated by reasonably adjusting the liquid flow rate to change the flow pattern of pump. In addition, the gas-liquid separation in the impeller is delayed by increasing the rotational speed and thus delays the pump surging occurrence, which increases the gas pumping ability. Consequently, the pump performance is improved. The critical gas volume fraction obtained by the existing surging prediction models are deviated with the experimental results. Thus, a surging prediction model for the volute centrifugal pump is urgently needed.