水锤效应（Water hammer effect）.docVIP

水锤效应（Water hammer effect） Water hammer is also called water hammer. Water (or other liquid) in the transport process, because the valve suddenly opened or closed, the pump suddenly stops suddenly, the opening and closing of guide vane and other reasons, the flow rate suddenly changes, while the pressure generated fluctuation phenomenon. 2 Y6 B1 RE5 R2 b- [water hammer effect is an image of the statement. It refers to the water pump in the starting and stopping when the water flow impact pipeline, a serious water hammer. Because the inner wall of the pipe is smooth, the water flows freely. When the open valve is suddenly closed or the feed pump stops, the flow will produce a pressure on the valve and pipe wall, mainly the valve or pump. As the pipe wall is smooth, the subsequent flow under the action of inertia, hydraulic rapid reach the maximum, and produce damage, this is the water conservancy water hammer effect, that is, positive water hammer. On the contrary, the closed valve in a sudden opening or water pump start, will also produce water hammer, called negative water hammer, but not the former big. ) f (Q), p#, P5, f The instantaneous pressure produced by water hammer can reach several times or even hundreds of times the normal working pressure in the pipeline. This large amplitude pressure fluctuation can result in strong vibration of the piping system, noise, and possibly damage to the valve joint. It has a great destructive effect on the piping system. In order to prevent water hammer, it is necessary to design the piping system correctly to prevent the flow rate too high. Generally, the design speed of the pipe flow should be less than 3m/s, and the speed of opening and closing of the valve should be controlled. B9 h* G0 G @# / | for pump, stop the pump and switch valve too fast, the water velocity changes sharply, especially the sudden stop caused by water hammer pump, water pump, valve, pipeline can damage, and cause the reverse pump, pipeline pressure r