A Conical Vortex Swirl Shaft Spillway Tunnel System

Abstract

The invention discloses a cyclone shaft flood discharging tunnel system. The system comprises a gate chamber, an upper flat section, a volute chamber, a shrinkage section, a shaft straight section, an outlet pressure slope section, and a lower flat sluicing section on the back side of the outlet pressure slope section; the volute chamber is of a conical structure having the same one shrinkage slope rate with a lower shrinkage section and smoothly joined with the shrinkage section; and an edge wall, tangential to and joined with the volute chamber, of the upper flat section is an inclined edge wall having the same shrinkage slope rate with the volute chamber. The conical volute chamber cyclone shaft flood discharging tunnel can reduce the possibility of water directly falling to the bottom of a shaft at the tail end of the shrinkage section, improves the energy dissipation effect, meanwhile, reduces the height requirement of the volute chamber, reduces the excavation quantity, and saves the engineering investment.

Description

Technical field [0001] The invention belongs to the technical field of flood discharge and dissipation in water conservancy and hydropower projects, and specifically relates to a swirling shaft flood discharge tunnel system. Background technique [0002] Due to its advantages such as low construction difficulty, flexible layout, and outstanding energy dissipation effect, the swirling shaft flood discharge tunnel has attracted more and more attention from the water conservancy and hydropower engineering community, especially as my country is currently in the blowout development stage of hydropower construction. Many high-head, large-flow, deep canyon high-dams and reservoirs are under construction or in the planning stage. In the case that conventional discharge structures cannot achieve good flood discharge and energy dissipation, swirl shafts are an emerging development of flood discharge and energy dissipation. Buildings are a good choice. Generally, the entire swirling shaft fl...

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Problems solved by technology

[0003] However, since the water flow entering the vortex chamber in the upper flat section has a certain width (that is, the normal water depth of the inner wall of the vortex chamber), the closer the water body is to the center of the vortex chamber, the easier it is for the water body to break free from the constraints of the mainstream, and then directly fall to the bottom of the shaft.

This is because the circumferential velocity of part of the water body in the direction of the free surface of the water flow gradually decreases during the vertical discharge process, so that it is not enough to support the bottom of the shaft and then falls directly, thereby reducing the energy dissipation effect, increasing the pressure on the bottom plate and even causing At the same time, at the connection position between the cylindrical vortex chamber and the upper flat section of the conventional swirl shaft flood discharge tunnel, due to the sharp turning of the water flow and the reverse action of the shaft vortex chamber wall, part of the water flow will climb to a higher level in the vortex chamber. location, which will undoubtedly increase the height requirements of the vortex chamber section and increase the project cost

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