缓闭式空气阀水锤防护效果研究（“研究生论坛”稿件）

为了研究缓闭式空气阀的水锤防护效果，在传统空气阀数学模型的基础上，根据缓闭式空气阀的工作原理，运用水锤理论和特征线方法，建立了缓闭式空气阀的数学模型，并给出了其求解方法。通过算例计算，比较了缓闭式空气阀与传统空气阀的防护效果差异，分析了影响缓闭式空气阀防护效果的各项因素，并给出了各项影响因素的最优值。计算结果表明，缓闭式空气阀能有效地防护负压、降低水锤正压，其防护效果与节流板位置变化的临界压力以及节流板孔口和空气阀孔口的面积比有关。研究成果为缓闭式空气阀的设计和运行管理等提供了科学依据。

Study on the protection efficiency of water hammer by non-slam air valve

In order to study the protection efficiency of water hammer by non-slam air valve, a mathematical model of non-slam air valve was set up based on the mathematical model of conventional air valve and the working principles of non-slam air valve. Solution method for the mathematical model of non-slam air valve was presented by using the theory of water hammer and the method of characteristics. Calculations were carried out for comparing the protection efficiency between the conventional air valve and the non-slam air valve. The influence factors of protection efficiency by the non-slam air valve were analyzed and optimum values of the factors were recommended. The calculation results show that the non-slam air valve can be used to decrease the water hammer negative pressure and positive pressure effectively. Its protection efficiency is related to the critical pressure of the throttle plate position change and the area ratio between the throttle plate orifice and the air valve orifice. Research results presented herein provide the scientific basis for the design, operation and management of non-slam air valve.