长距离输水系统中空气阀的运行特性研究

Study on the Operation Characteristics of Air Valve in Long-distance Water Supply System

长距离管道输水工程中,空气阀是重要的排气和负压控制设备。准确模拟空气阀运行特性,对整个供水工程的安全至关重要。为此,分析了空气阀的工作特点,在热力学第一定律的基础上建立了新的空气阀的数学模型,并采用特征线方法,对空气阀的水锤防护作用进行了计算分析。计算结果发现,与采用传统的空气阀数学模型相比,空气阀的进排气过程具有一系列新的特性。

Air valve is an important device of expelling gas and controlling negative pressure in long water supply system. Accurate simulation of the air-inlet and air outlet process of air valve is directly relative to the safety of water supply engineering. For this reason, the operational principles of air valve are analyzed and new mathematic model of air valve is built based on the first law of thermodynamics. Protective function of air valve in transient process caused by valve closing is analyzed with the characteristics method. The results showed the new mathematic model of air valve present a series of new characteristics in the process of air-inlet and air-outlet comparing with the old mathematic model based on ideal-gas state equation.