Research On Water Hammer Suppression Method Based On Valve Closing Rule In Hydraulic Pipeline

The problem of water hammer seriously threatens the normal operation of hydraulic pipeline.In order to restrain the pressure of water hammer in pipeline and ensure the normal operation of pipeline,a variety of water hammer suppression methods have been put forward under different conditions.This paper is mianly about indirect water hammer in closed valve water hammer,which aims to reduce the damage caused by the water hammer pressure to pipeline by suppressing the maximum surge pressure in hydraulic pipeline through a certain valve closure rule.Specifically,this paper focuses on the following aspects:(1)The present situation of water hammer suppression method based on valve closing rule is analyzed and studied.A water hammer suppression method is proposed under the condition that the valve closing time is not fixed to suppress the maximum surge pressure in pipeline.In this method,the valve closing time is also treated as a variable,and the valve closing rule corresponding to the closing time is sought,and the final valve closing rule will have greater applicability.(2)The influence factors of water hammer in hydraulic pipeline system are analyzed and studied.The analysis of pipe diameter,pipe length and water hammer pressure wave propagation speed is helpful to suppress water hammer pressure in pipeline by passive method.(3)On the basis of linear flow regulating valve and ball valve,the closing rule of valve which suppresses the maximum surge pressure in pipeline is obtained by Genetic Algorithm.Researches on time-limited water hammer suppression and time-unlimited water hammer suppression were carried out for both types of valves.For the time-unlimited wa-ter hammer suppression,compared with the results obtained under the three kinds of pipes,it is found that when the valve closing time is different,the valve closing rule will be completely different,and the water hammer suppression effect of different valve closing rules is very different.For a certain pipeline,the valve closing rule obtained by time-unlimited water hammer suppression is unique.Compared with the time-limited water hammer suppression,the valve closing rule obtained under time-unlimited has a better water hammer suppression effect.(4)In order to save the time of simulation and optimization,the valve closing rule of the maximum water hammer pressure in the pipeline is obtained more quickly.Based on many sets of simulation data,a model of predicting valve closure rule is obtained by using radial basis neural network training.The model can output the relevant data of valve closure rule on the basis of direct input pipeline parameters.Compared with the simulation results,it is found that the prediction results of the model are basically consistent with the simulation results,which shows that the model can be used.(5)In order to test the water hammer suppression effect of valve closing rule and verify the effectiveness of valve closure rule,a simple water hammer test platform is built,and a water hammer suppression test based on valve closing rule is carried out on the test platform.Compared with the test results and simulation results,the effectiveness of valve closing rule is verified.