LIPeng-yu,YUXiao-dong,WANGKai-lang,et al.Limiting Water Hammer Characteristics of Gravity Flow Valve Closing and Corresponding Valve Closing Law[J].China Water & Wastewater,2024,40(13):49-54.
Limiting Water Hammer Characteristics of Gravity Flow Valve Closing and Corresponding Valve Closing Law
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第13期
Page:
49-54
Column:
Date of publication:
2024-07-01
- Keywords:
- gravity flow; limiting water hammer; valve closing law; pressure
- Abstract:
- The closing of valves causing water hammer is a critical threat to the safety of long- distance gravity flow water transmission projects in pipeline systems. The limiting water hammer characteristics of the gravity flow valve closing were initially analyzed, and the resulting characteristics could be divided into two stages. The first stage involved the recovery of static water head value, during which the pipeline pressure showed a rising trend that was controlled by the valve closing rate. The second stage involved the fluctuation section of water hammer pressure. As the pipeline pressure returned to the static water head value, the water hammer wave became gradually more apparent, and the maximum pressure was controlled by the valve closing rate in this section. The theoretical formula for the maximum limit of water hammer pressure was further derived. It was explained that the maximum water hammer pressure depended on the second stage valve closing law of long?distance gravity flow water transmission projects, in combination with the characteristics of water hammer. Using an actual long?distance gravity flow water transmission project as a case study, this paper simulated the transition process of end valve closing, analyzed the water hammer pressure of the system under different valve closing laws, and verified the water hammer characteristics and theoretical calculation formula of gravity flow valve closing. Based on this rationale, a method for selecting the rate of valve closing and the opening of the break point was proposed.
Last Update:
2024-07-01