水电能源科学

针对泄压阀的水锤防护特性和参数选择问题，根据水锤基本方程，建立了泄压阀的水锤计算模型，以云南省某重力流输水系统为例，在给定泄压阀启闭压力和启闭速率的条件下，分析了泄压阀口径和过流特性对水锤防护效果的影响及泄压阀动作过程中开度的变化过程。结果表明，泄压阀可有效减小关阀水锤压力；泄压阀口径越大，其泄压能力越强，水锤防护效果越好；快开型泄压阀更有利于水锤升压过程中的快速泄压，泄压过程中开启的最大开度更小；泄压阀的启闭并非瞬间完成，可能出现“初始关闭—开启—关闭—再次开启—再次关闭”的现象。

Aiming at the issues of water hammer prevention characteristics and parameter selection of pressure relief valve, a water hammer calculation model of pressure relief valve was established based on the basic equation of water hammer. Taking a gravity flow water delivery system in Yunnan Province as an example, under the conditions of given opening and closing pressure and rate of pressure relief valve, the influence of pressure relief valve diameter and flow characteristics on the water hammer prevention effect and the change of opening degree during the operation of pressure relief valve were analyzed. The results show that the pressure relief valve can effectively reduce the valve-closing water hammer pressure in the pipeline. The larger the diameter of pressure relief valve is, the stronger its pressure relief capacity is, the better the water hammer protection effect is; The quick-opening type pressure relief valve is more conducive to the rapid pressure relief in the process of water hammer pressure boost, and its maximum opening degree during the transient process is smaller. The opening and closing of the pressure relief valve is not completed instantaneously, while may occur "closing to opening to re-opening to re-closing" with the change of main pipe pressure.