长距离有压输水工程泵站水锤的数值分析

Numerical analysis of water hammer in a long-distance pressurized water transfer project

综合考虑了长距离有压输水系统中的泵、泵后阀门、空气阀、调压井、异性串联管、下游水库等各种内、外边界条件,采用特征-差分方法,针对实际工程的泵站水锤问题,通过数值方法对事故停泵后重新启泵的时间间隔、输水系统管线糙率等要素进行了敏感性分析。结果表明,合理的启泵时间间隔有助于改善有压输水系统及其部件在水力过渡过程中的水动力特性,并缩减调压井尺寸及相应工程造价;管线糙率对水头损失和水锤波衰减存在影响,对全系统在水力过渡过程中的水动力特性影响较小。

Taking various internal and external boundary conditions of pumps,valves,air valves,surge tanks,heterogeneous series of pipes and the downstream reservoir into consideration for a long-distance pressurized water transfer system,water hammer induced by pump failure in engineering construction was discussed based on the characteristic difference method.Sensitivity analysis of the time interval of pump restarting after pump failure and the roughness of the pipeline was carried out by numerical method.The results show that the reasonable time interval between pump failure and pump restarting can improve the hydrodynamic characteristics of the pressurized water transfer system as well as its components in the hydraulic transition process,which can reduce the size of the surge tank and the engineering cost.The roughness affects head loss and water hammer attenuation but has little influence on the hydrodynamic characteristics of the whole system in the hydraulic transition process.