泵后球阀兼作泄压阀的水锤防护研究

Research on Water Hammer Protection of Ball Valve Behind Pump Serving Concurrently as Pressure Relief Valve

对于高扬程泵后设置空气罐防护的输水工程,水泵断电时输水系统的倒流动力往往很大。针对输水系统倒流动力过大而导致所需空气罐体积剧增的问题,提出了一种泵后球阀兼作泄压阀的水锤防护方案,建立了泵后球阀的数学模型,并分析了泵后球阀"先关后开再关"操作方案的可行性。结合实际长距离供水工程,对比分析了泵后球阀一段直线关闭、球阀两段折线关闭与泵后球阀"先关后开再关"操作方式的水锤防护效果,并对泵后球阀开启阶段的目标开度进行了敏感性分析。结果表明,泵后球阀采用"先关后开再关"的操作方式能够解决输水管道超压问题,有效减小所需空气罐的体积,但开阀阶段球阀的目标开度不宜过大。

For the water supply project with high head,which air vessel is installed behind the pump,the reverse flow force of the water supply system is serious when the pump happens the outage.The volume of the air vessel needs to be increased due to the large reverse flow force caused by the pump outage.In order to solve this problem,a water hammer protective scheme is proposed,which the ball valve as the pressure relief valve is installed behind the pump.The mathematical model of the ball valve was established and the feasibility of the "close-open-close" operation law of the ball valve was analyzed.Based on the long distance water supply project,the water hammer protective effects of closing ball valve by a straight line,two-stage folding line,and "close-open-close" law were compared.The results show that the operation of "close-open-close" law can solve the problem of pipeline overpressure and effectively reduce the volume of air vessel.During the valve opening phase,the target opening of the ball valve should not be too large.