stage of pump meaning in English

泵级

An operation decision method for multi - stage pumping station system with adjustable - blade propeller pump is presented . it includes optimal water level of individual stage of pumping station and optimal operation method of every pump . the paper describes some mathematical models and decision making technique of multi - stage pumping station
本文针对大型引水工程整个系统在进入稳态运行后，在各站的抽水流量或首级站进口水位发生变化的情况下及时做出运行决策，调整各梯级站间的水位，达到整个系统总能耗最小的目的。
The results show that the increase of vacuum energy can not expand the influence scope of vacuum degree obviously when vacuum degree under membrane is high . the vacuum degree in the pvds is higher than vacuum degree in the sand drains , and the vacuum degree in the sand drain is higher than vacuum degree in the silt at the same depth in the ground during the initial stage of pumping
分析结果表明：当膜下真空度较高时，真空能量的增加不会明显增大真空度的影响范围；在抽真空的初期，一般在地基相同的深度处：塑排真空度砂井真空度淤泥真空度。