离心泵发展的趋势之一是提高单级扬程,从而减少高扬程泵的级数,让泵的结构更简单.为使泵的比转数ns处于高效率范围内,在提高单级扬程的同时,泵的转速n也应提高.但受泵汽蚀性能,零件强度以及高速驱动的实现等因素的限制,泵的单级扬程不可能无止境地提高.因此,无论在目前,还是在可以预见到的未来,多级泵都是要被大量采用的.特别对在某些特殊场合使用的泵更是如此.例如,适当减小井用潜水电泵的单级扬程,从而增加 Centrifugal pump development trend is to improve the single-stage lift, thereby reducing the high-lift pump series, so that the pump structure is simple. In order to pump the specific speed ns in the high efficiency range, while improving the single-stage lift , The pump speed n should also be increased.But by the pump cavitation performance, parts strength and the realization of high-speed drive and other factors, the pump single-stage lift can not be increased indefinitely.Therefore, whether at present or in the foreseeable To the future, multi-stage pumps are to be used in large quantities, especially for pumps used in some special occasions, for example, by appropriately reducing the single-stage lift of the submersible pump, thereby increasing