The Research On Water Hammer Control Of Pumping Piping System Based On Self-operated Control Valve

The water hammer phenomenon in the pumping pipeline system can cause great damage to the pump and pipeline,which exerts seriously a negative impact on the safe operation of the water transfer project.In order to avoid water hammer in the pumping pipeline system,we should select a safe,economical and convenient water hammer protection measure according to the characteristics and conditions of each pumping pipeline system.This is of great significance to the safe operation of the water transfer project.In this paper,the numerical simulation method is used to research the self-operated control valve,with its structural performance and the characteristics of water hammer protection being analyzed and summarized.The closed valve control of the self-operated control valve is optimized.The protection scheme of water hammer based on self-operated control valve is developed aiming at the stopping water hammer of the pressure pipeline system in the pumping station.This scheme can provide reference for the stopping water hammer protection of the pumping pipeline system.According to the water hammer wave theory,the water hammer wave formula is deduced.Based on the characteristic line method,the basic differential equation of water hammer is solved,and the various boundary conditions required for the water hammer solution process are establishedThe structure,principle and characteristics of the self-operated control valve were analyzed.Under different opening degrees,the flow resistance coefficient of the valve was simulated by Fluent software.Compared with several other commonly used check valves and water hammer protection equipment,it is concluded that the self-operated control valve has certain advantages in production cost,installation and maintenance,and energy saving.The Hammer software is used to optimize the valve closing process of the self-operated control valve.Through this simulation calculation,it is found that different quick closing angle and slow closing time of valve have different effects on pressure fluctuation of pipeline.The maximum pressure of the pipeline is directly proportional to the quick closing angle and inversely proportional to the slow closing time of the valve;The maximum reverse speed of the pump is inversely proportional to the quick closing angle and directly proportional to the slow closing time of the valve.It is necessary to simulate and optimize the valve closing control optimize the water hammer protection effect of the self-operating control valve.Water hammer protection schemes that based on the self-operated control valve was developed and verified by engineering simulation.Through this simulation calculation,it is found that the self-operated control valve can protect the pump unit and piping when the water hammer occurs,but it can not eliminate the negative pressure in the pipeline.After optimizing the valve closing control of the self-operated control valve,the self-operated control valve can be used together with the air valve to bring the water hammer pressure into the specifications.Surge tank is costly and difficult to construct and maintain.The use of self-operated control valve and air valve water hammer protection scheme can ensure the safety of water transfer project without surge tank.It can also reduce the investment in water hammer protection in pumping pipeline system.