连接管长度对调压井水位波动和水锤压力的影响

Influence of lateral pipe length of surge tank on surge wave and water hammer

本文目的在于回答调压井连接管较长时,其内水体惯性对调压井水位波动和水锤压力有何影响,有多大影响,设计中能不能忽略。文中首先通过理论和解析方法研究了连接管影响的性质和规律;然后针对典型的水库———调压井———阀门引水系统,用特征线法计算,详细分析了不同连接管长度下调压井水位波动幅值、阀门端水锤压力上升率、水锤穿井率的变化规律;最后以某抽水蓄能电站为实例进行了对比计算。研究表明,连接管增长使调压井水位波动幅值减小,但幅度有限,通常可忽略;连接管使水锤压力和穿井率增大,在实际工程可能的范围内其增幅有时较大,应加以考虑。

This paper aims at answering the questions:What kind of influences does the water inertia in the lateral pipe of a surge tank exert on the surge wave and water hammer?In what extent are the influences?And when should their influences be taken into account in calculations and designs?After theoretical and analytical analyses of the influencing characters,the authors simulated a hydraulic transient process in a typical system of reservoirsurge tankvalve by using the method of characteristics.Investigation was made on the variations of the surge wave amplitudes in the surge tank,and the water hammer pressures at the valve and in the headrace tunnel with different lengths of the lateral pipe.Pressure heads at the turbine of a pumped storage project were calculated to see the difference of pressures with the lateral pipe being considered and ignored.In view of practices,the influences of lateral pipe length on surge wave can be ignored while attentions should be paid to its effects on water hammer.