Cave plug flood discharging cave connected through open channel

Abstract

The invention discloses a cave plug flood discharging cave connected through an open channel. The flood discharging cave comprises an inlet section, an open channel section, a vertical shaft section,a lower flat section, and cave plug sections which are sequentially arranged in the water flow direction. The open channel section is vertically communicated with the vertical shaft section; the vertical shaft section is vertically communicated with the lower flat section; the number of the cave plug sections is multiple; and the cave plug sections are closely connected with one another. The connecting mode, the structure and the arrangement mode of a cave plug energy dissipater are improved, the dynamic load of a bottom plate of the vertical shaft section can be reduced, and air in a verticalshaft can be exhausted easily. During flood discharging, water flow in a reservoir flows into the vertical shaft from the open channel and is changed into pressure flow from non-pressure flow, so that the reduction of the hydrodynamic load acting on the bottom plate of the vertical shaft section and the discharge of the air in a cave are facilitated. The flood discharging cave plug section adoptsmulti-stage contraction type plugs, which is good in energy dissipation effect, and can adapt to high-flow and high-water-head working conditions.

Description

technical field [0001] The invention relates to the technical field of energy dissipation in water conservancy and hydropower projects, in particular to a plug flood discharge tunnel connected by an open channel. Background technique [0002] The principle of hole plug energy dissipation is to reduce the energy of high-speed water flow by reducing the hole diameter of the section where the hole plug is located, and to reduce the energy of high-speed water flow by using the sudden contraction and expansion of the water flow through the hole plug to reduce the flow velocity of the downstream water flow and reduce the Downstream river bed scour. In the actual project, the flood discharge tunnel has the characteristics of low position, submerged outlet, and strong pressure inside the tunnel. The energy dissipation of the plug can make full use of these characteristics, greatly improving its energy dissipation effect, and reducing the risk of cavitation damage at the same time. ...

AI Technical Summary

Problems solved by technology

[0003] Existing plug flood discharge tunnels generally have the following disadvantages: 1. In the case of large flow and high head water flow, the reservoir and the flood discharge tunnel are connected by pressurized pipes, and the water flow in the pipe is pressurized flow

Often in actual engineering, the pressure at the bottom plate of the shaft section is the highest, and it will increase with the rise of the reservoir water level. The water flow directly impacts the bottom plate, and deformation occurs under the action of hydrodynamic load, which increases the risk of engineering damage

2. Under normal circumstances, the working gate is set at the entrance position, which will cause the problem of no water in the shaft section at the beginning of the gate opening, and the air in the tunnel will be carried to the plug section at the beginning of the gate opening, and there will be a clear and full flow transition in the flood discharge tunnel The flow state is not conducive to the prevention of cavitation and cavitation in the plug section of the flood discharge tunnel

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