基于阀门关闭策略的重力流管路水锤控制分析

Water hammer control analysis of gravity flow pipeline based on valve closing strategy

在输水管路中一旦出现水锤问题,不仅严重影响输水工程安全,还会制约输水工程的进一步发展。重力流作为高效节能的输水方式,有必要对其阀门关闭方式进行研究,改善水锤问题以提高安全性。以MATLAB为工具进行数值模拟计算,先对阀门两阶段调节分析,发现先快关后慢关的阀门关闭方式对水锤的控制效果优于先慢关后快关方式;再对阀门两阶段关闭方式中的快关时间和快关关闭量影响因素进行研究,发现采用"4 s快关65%,16 s慢关35%"连续两阶段关闭方式能够有效控制水锤,而且阀门的关闭量是影响管路中水锤压强的主要因素;进一步分解阀门的快关和慢关关闭过程,增加动作次数,采用"1 s快关35%,3 s快关30%,12 s慢关25%,4 s慢关10%",水锤最大压强得到抑制,同时阀门完全关闭后的压强波动情况也得到改善。将在两阶段间加入时间间隔的关闭方式与连续两阶段的关闭方式进行对比,发现前者对水锤问题也能发挥良好的控制效果。因此,在设备无法满足多次连续动作时,采用在两阶段间加入时间间隔的关闭方式也能有效的控制管路水锤。

Water hammer occurring in water pipeline not only seriously threatens the safety of water transfer project,but also restricts further development of water transfer project.However,as an efficient and energy-saving method of water delivery,it is necessary to study valve closing mode of gravity flow to solve the water hammer problem.After numerical calculating with MATLAB,and analyzing two-stage adjustment of the valve,it is concluded that the mode of first closing fast and then closing slow has better control effect on water hammer than that of first closing slow and then closing fast.The influencing factors of fast closing time and fast closing amount in two-stage valve closing mode were studied.It is found that water hammer can be effectively controlled by adopting the continuous two-stage closing mode of“4 s fast closing 65%,16 s slow closing 35%”,and the closing a mount of the valve is main factor affecting the surge pressure in the pipeline.After closing process is further decomposed,increasing the number of action,adopting"1 s fast closing 35%,3 s fast closing 30%,12 s slow closing 25%,4 s slow closing 10%",the maximum pressure of water hammer is suppressed,and the pressure fluctuation is also improved after the valve is closed completely.It is found that the closing mode of adding a time interval between the two stages can also exert good control effect on water hammer after compared it with the continuous two-stage closing mode.Therefore,when the equipments cannot meet multiple continuous actions,the closing mode of adding a time interval between two stages can also control the water hammer in the pipeline effectively.