多工况下分流叶片离心泵非定常空化特性分析

摘要

为了进一步优化离心泵叶轮流道,提高离心泵的空化性能,对有/无分流叶片离心泵进行全流道三维非定常湍流空化数值模拟,分析0.4Q～1.0Q工况下泵的空化性能.结果显示:在空化充分发展的情况下,无分流叶片离心泵扬程对NPSH的降低比较敏感;添加分流叶片后,离心泵的扬程提高,叶轮进口部位的低压区域减少,叶轮内湍动能明显减小,泵的抗空化性能明显增强;随着流量的降低,泵的临界空化余量降低,但泵内发生严重空化的速率逐渐加快;当离心泵内发生严重空化时,空泡将堵塞整个叶轮流道.%In order to further optimize flow passage of impeller and improve the cavitation performance of centrifugal pump,the numerical simulations of three dimensional unsteady turbulent flow in whole flow passage of a centrifugal pump with or without splitter blades are carried out to analyze the cavitation performance of pump under 0.4Q-1.0Q conditions respectively.The results show that:(a) in the case of full development of cavitation,the head of centrifugal pump without splitter blades is more sensitive to the reduction of NPSH;(b) after adding splitter blades,the head of centrifugal pump is improved,the low pressure area of impeller is reduced,the turbulent kinetic energy of impeller is decreased obviously and the anti cavitation performance of pump is obviously enhanced;(c) with the decrease of flow rate,the critical cavitation margin of pump is reduced,but the rate of serious cavitation in pump is gradually increased;and (d) when a serious cavitation occurs in centrifugal pump,the cavity will block the flow of impeller.