在具体分析立式混流泵结构特征和启动特点的基础上，以水泵启动过程最大水锤压力为控制目标，设计正交试验表，进行三维水锤计算并分析水泵电机启动时间、蝶阀开启时间和水泵叶片角度等因素对水泵启动过程的影响，为立式混流泵启动操作优化提供了有力的理论依据． 研究结果表明:随着电机启动时间的增加，水泵最大启动水锤压力逐渐降低，最大降幅为 4． 4%;随着蝶阀开启时间增加，水泵最大启动水锤逐渐上升，最大增幅为 3． 4%;而随着叶片角度的增加，水泵最大启动水锤压力的变化比较复杂;电机启动时间对启动过程最大水锤压力的影响最为显著，而蝶阀开启时间对最大水锤的影响最弱． 同时，考虑到水泵在部分叶片角度下的扬程曲线中明显存在马鞍区域，从保障水泵正常运行安全性的角度出发，水泵启动参数的最优配置为:电机启动时间 26 s、蝶阀开启时间 30s 和叶片角度 －3°．

In the investigation,the structure features and start-up characteristics of vertical mixed-flow pumps areanalyzed.Then,with the maximum water hammer pressure in the start-up process as the control target,an orthogo-nal test table is designed to calculate the 3-D water hammer and analyze the influences of the electric motor start-uptime,the butterfly valve opening time and the blade angle on the pump start-up process,which provides a strongtheoretical basis for the start-up operation optimization of the vertical mixed-flow pump.The results show that (1)as the electric motor start-up time increases,the maximum pressure of the pump start-up water hammer decreasesgradually,with a maximum amplitude of 4.4%; (2) as the butterfly valve opening time increases,the maximumpressure increases gradually,with a maximum amplitude of 3.4%; (3) with the increase of the blade angle,thechange of the maximum water pressure becomes more complicated; and (4) the effect of the electric motor start-uptime on the maximum water hammer pressure is the most significant while the effect of the butterfly valve openingtime is the weakest.Besides,by taking into account the fact that there exist saddle regions in the head curves atcertain blade angles and from the perspective of guaranteeing the normal running of water pump,the optimal start-up parameters are found to be an electric motor start-up time of 26s,a butterfly valve open time of 30s and a bladeangle of －3 °.