How it works
Water overflow: When the upstream water level rises to exceed the top of the fixed overflow weir, the water begins to overflow the top of the weir and flow down along the weir surface. During this process, the water flow is resisted by the weir surface, the flow rate gradually decreases, and the direction of the water flow also changes.
Flow control: Fixed overflow weirs control flow by setting different weir crest heights. When the upstream water level is low, the water will not overflow the weir crest, but continue to flow through other channels or pipes. When the upstream water level rises to exceed the weir crest, the water begins to overflow and flow down through the weir. Therefore, by adjusting the weir crest height, precise control of the flow can be achieved.
Energy conversion: During the overflow of water, part of the kinetic energy of the water flow is converted into potential energy, and the water flow is also subject to certain resistance. In this process, the energy of the water flow is converted and consumed to a certain extent, thereby achieving the control and regulation of the water flow.
Types and characteristics
Type: Fixed overflow weirs can be divided into many types according to their shapes and uses, such as thin-walled weirs, wide-top weirs, etc. Each type of fixed overflow weir has its specific application scenarios and advantages and disadvantages.
Features: The fixed overflow weir has the characteristics of simple structure, easy maintenance, and precise flow control. At the same time, it can also adapt to different water flow conditions and water level changes to ensure that the water flow remains stable and orderly during the overflow process.
Application Examples
Fixed overflow weirs are widely used in water conservancy projects, urban drainage systems and other fields. For example, in water conservancy projects, fixed overflow weirs can be used to control the flood discharge of reservoirs to ensure that the reservoirs operate below the safe water level; in urban drainage systems, fixed overflow weirs can be used to regulate the peak flow of rainwater runoff and reduce the size and construction cost of downstream rainwater dry ditches.
