|
|
|
| Analysis of branch vent draining process in complex pipeline system based on improved air valve model |
| LIANG Xing1*, DENG Fei1, LIU Meiqing2, GAO Ganggang1, CAO Hanwen1 |
| 1. Jiangxi Province Key Laboratory of Precision Drive & Control, Nanchang Institute of Technology, Nanchang, Jiangxi 330099, China; 2. School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei 430072, China |
|
|
|
|
Abstract In order to analyze the hydraulic transition process induced by the closure of upstream valve of branch pipe in the complex pipeline system, an improved air valve calculation model was established by using the method of gradually advancing the air volume from air valve to the downstream. Taking a diversion project as an example, two air valve models were used to calculate the corresponding water hammer. The results show that when the classical air valve calculation model is adopted, the ″simulated″ flow is caused by the large upstream elevation, and the simulation results deviate greatly from the engineering practice. The branch pipe flow gradually decreases to 0 based on the improved air valve calculation model, and the upstream flow of the main line at the meeting point gradually increases, the downstream flow gradually decreases, and the main line flow finally reaches 121.5 m3/s. In the transition process, the water level of each surge tank of the main line decreases, but there is no leakage. Water level of each surge tank and meeting point pressure are similar to the steady-state calculated values(main line flow 121.5 m3/s), and the maximum deviation is only 0.16 m, which proves the accuracy of the improved air valve calculation model. It provides a new method for the study of filling and draining of complex water conveyance system.
|
|
Received: 07 January 2022
|
|
|
|
|
|
|
