空气阀水锤防护特性的主要影响参数分析及优化

Analysis and Optimization of Main Influencing Parameters for Water-hammer Prevention Characteristic of Air Valves

对空气阀水锤防护特性的主要影响因素进行了试验分析。结果表明:在合理位置安装合适进排气孔口径的空气阀可有效防止因水柱分离再弥合而导致的巨大水锤升压,但空气阀的防护效果受安装位置和进排气孔口径的影响较大;口径过大,在排气过程中会产生较大的水锤升压,口径过小则可能因进气量和进气速度不够而达不到水锤防护的效果,实际应用中应对进、排气孔口径进行优化或采用"快进慢出"的结构形式;对本试验装置,空气阀应安装在首先产生水柱分离的位置,不合理的安装位置会加剧管道中的水锤压力上升。在此基础上,建立了空气阀参数和泵出口阀关闭程序的优化模型,并采用遗传算法进行求解。将上述优化方法应用到实际供水工程的水锤防护,提出了适宜的水锤防护措施。

The main influencing parameters for water-hammer prevention characteristic of air valves are analyzed through experiment. The result indicates that the air valve with reasonable size and installation position can prevent high water hammer pressure caused by water column separation. However, the prevention effect is impressible to the size and installation position of air valve： too large size will cause large pressure during the venting process, while too little size can not obtain prevention effect for insufficient air quantity and slow intake speed. So the air valve should have rapid intake speed and slow venting speed. For the experimental system in this study, the air valve should be installed in the position where the water column separation occurs firstly. Based on the analysis result, the optimization model for the air valve parameters and closure procedure of pump outlet valve is set up and solved by using genetic arithmetic. In the end, the above optimization method is used for the water-hammer prevention of a practical water-supply project and the suggestion of suitable prevention measure is proposed.