运用水锤理论和特征线法, 结合工程实例, 对采用缓闭式蝶阀、空气阀和单向调压塔等防护措施的长距离多泵 联合运行输水系统停泵水锤进行计算和分析, 得到了管道沿程的水头包络线以及泵端性能参数相对值的变化曲线。 计算结果表明, 无防护措施下最小水锤水头较低, 泵端性能参数变化较大; 泵端蝶阀防护可以有效地控制泵端性能 参数流量和转速变化幅度, 但水头的变化出现了振荡, 最小水锤水头值降低; 采用空气阀+ 泵端蝶阀防护可以有效 地增加最小水锤水头值, 只在管道局部出现负压, 但与泵端蝶阀防护相比性能参数变化有所增大; 单向调压塔+ 泵 端蝶阀对停泵水锤防护效果最为明显。为了减小单向调压塔数目, 最终选择单向调压塔+ 空气阀+ 泵端蝶阀的组 合作为最终的防护措施, 与无防护措施相比, 组合防护下整个管道不出现负压, 泵端水头虽出现了振荡, 但幅度不 大, 流量最大变化幅度下降0. 15, 转速最大变化幅度下降0. 7, 转矩振荡时间变短。

The wat er hammer theor y and character istic cur ves method combined w ith engineer ing ex ample w ere used to analyze the pump2sto pping w ater hammer of water tr ansfer system with lo ng distance and cooperat ion w ith multiple pumps w hich a2 dopts such pr eventive measures as liquid2o ff butter fly valve, air valve, and one2w ay surg e tank. The w ater hammer head line a2 long the pipeline and curv e fo r t he relative values o f perfo rmance parameters of the pump w ere obtained. The results show ed that the minimum w ater hammer head is lower and var iatio n of per formance parameter s of pump is larg er w itho ut preventiv e measures; t he pro tection w ith the butterf ly valv e can effectively contr ol the var iatio n of per formance parameter s of pump flow rate and speed, but the var iatio n of w ater hammer head shows oscillatio n and the minimum w ater hammer head is low er than that wit ho ut pr ev ent ive measur es ; the pr otectio n w it h air va lve and butterfly v alv e can effect ively incr ease the minimum w ater hammer head, the negative pressur e a ppears but o nly in the local a rea, and the var iatio n of perfo rmance parameters o f pump is lar ger compar ed w ith that of the butter fly v alve protection; and the pro tect ion effect w it h one2way surg e tank and butter fly v alv e is the most sig nificant. In o rder to r educe the number of one2way surg e tanks, combinatio n of the one2way surg e tank, air valve, and butter fly valve w as selected as t he final pr eventive measur e. Compared w ith t he pump w ithout pr eventive measur es, neg ativ e pr essure disappear ed in the who le pipe, altho ug h the w ater head showed oscillation w ith low range. The max imum v ariat ion of flow r ate dr opped by 0. 15, the max imum v ariat ion of rot ational speed dr opped by 0. 7, and the oscillatio n time o f the tor que be2 came sho rter .

河南省水利勘测设计研究有限公司项目( 技2008228) ; 河南省高等学校青年骨干教师资助计划