Study On Whether The Stop Hydraulic Calculation Model Transition In Large Caliber And Long Distance Flat Water Pipeline Hydraulic Calculations Of The More

With urban development and the improvement of living standards, China's rapid development of long distance water supply project construction, but how to ensure the safe operation of long distance pipeline problems in the engineering sector, aroused great attention. Prone to long-distance water column separation and drying of water column separation, resulting in serious water hammer damage. Therefore, long-distance water diversion project in the most common and most prominent problem is the issue of broken water hammer protection.In this paper, based on previous long-distance water pipelines in a variety of hydraulic fluid and a variety of mutual conversion between flow described. Analyzed the movement of pressure pipeline features balloon, balloon boost damage and the best exhaust pipe means, on the broken water hammer in the formation process of a deep step. The paper expounds the commonly used hydraulic transient characteristics method, and the occurrence of drying chamber of the type of space and different types of cavity and different calculation method to calculate the boundary conditions. Combination of various types of boundary conditions established basic mathematical calculation of water hammer model, the language of the preparation of water hammer protection for computer visualization of calculation procedures, using computer simulation.This paper mainly long distance and large diameter pipelines over the availability of off flat water hammer calculation results compared to research. Mainly through two different mathematical models of water hammer pump stops Cavities calculated to compare the results. Model 1:Calculation of pipe regardless of whether the transition process in the hydraulic water column separation occurs, the water hammer calculations Junan no-stop or stop occurred in some border points are calculated, that is, no broken water hammer calculation model; Model 2, in transient pipe flow, both the water column break occurred at any point, are separated by water column model of water hammer, water hammer that is off the mathematical model. There are two models under the same conditions in all calculations, a comparative analysis of different mathematical models on the long-distance pipeline accuracy of hydraulic transition and to conclusions.Finally, Ping Kong of Zhuhai broken water pipes as an example simulation of water hammer. According to the characteristics of the two models, all under the same conditions on the calculation results of the two models were compared to verify the two models in the broken water hammer protection for the calculation of the different effects, for the water line so effective water hammer provide a more scientific basis for protection.