Influence of different valve closing rules and outlet form on pipeline water hammer

In order to study the impact of different closing methods of pipeline end valves on the water hammer at the end of the pipeline and the overall water hammer pressure under accident conditions,aiming at the characteristic of the modeling and calculation of long-distance pressurized water pipelines with simple pipelines,fewer types of solution information and large amounts of data,the characteristic line method was used to simulate the hydraulic transient process of the water supply pipeline of Shandong Laicheng Power Plant,and the influence of different valve closing laws on the water hammer at the end of the pipeline was analyzed. The results show that the closing law of the outlet valve has a great influence on the end water hammer. Due to the limitation of the valve itself,a large end water hammer will still be generated when the outlet valve is closed according to the optimal closing law.Other protective measures are required to eliminate or reduce the end water hammer. A new type of pipeline water outlet that can effectively reduce water hammer at the end is proposed and verified.Through comparison and verification,it is found that the maximum internal water pressure of the pipeline drops from 128 MPa to 70 MPa after using the new type of water outlet,which can effectively reduce the peak water hammer pressure and prevent pipeline accidents caused by outlet valve failure or loss of power,and will further improve the safety and stability of water pipelines,and the cost of transformation will be lower. Research results provide new ideas for water hammer protection at the end of the pipeline.