H-shaped shaft flood discharge hole

Abstract

The invention relates to an h-shaped shaft flood discharge hole comprising a flood discharge hole and a shaft, wherein the shaft is arranged at the closed end of the flood discharge hole and communicated with the flood discharge hole and comprises a first shaft and a second shaft; the first shaft is positioned above the flood discharge hole, the centre line of the first shaft is vertically intersected with that of the flood discharge hole, the upper part of the first shaft is connected with a water flow approach channel, and the lower end of the first shaft is closed; the centre line of the second shaft is parallel to that of the first shaft, the upper end of the second shaft is closed, and the lower end of the second shaft is connected and communicated with the top of the flood dischargehole; the first shaft is communicated with the second shaft through a joint segment; and the first shaft and the second shaft are combined into an h-shaped outline. The first shaft of the h-shaped shaft flood discharge hole is a double-volute chamber air entraining type swirling shaft.

Description

technical field [0001] The invention belongs to the field of flood discharge tunnels of water conservancy and hydropower projects, and in particular relates to a submerged vertical shaft flood discharge tunnel used under the conditions of high water head, large flow rate and from no-pressure flow to pressurized flow. Background technique [0002] The unpressurized flow in the open channel with high water head and large flow is introduced into the submerged flood discharge tunnel through the shaft, in essence, the water flow transitions from the unpressurized internal flow discharge facility (shaft) to the pressurized internal flow facility (spill tunnel), so the water flow Unfavorable hydraulic phenomena such as hydraulic jumps are prone to occur in the flood discharge tunnel, which affects the safe operation of the flood discharge tunnel. In the existing technology, through the structural improvement of the shaft (for example, designing the shaft as a double-vortex aeration...

AI Technical Summary

Problems solved by technology

[0002] The unpressurized flow in the open channel with high water head and large flow is introduced into the submerged flood discharge tunnel through the shaft, in essence, the water flow transitions from the unpressurized internal flow discharge facility (shaft) to the pressurized internal flow facility (spill tunnel), so the water flow Unfavorable hydraulic phenomena such as hydraulic jumps are prone to occur in the flood discharge tunnel, which affects the safe operation of the flood discharge tunnel.

In the existing technology, through the structural improvement of the shaft (for example, designing the shaft as a double-vortex aeration type swirl shaft), setting a pressure slope at the exit of the shaft can stabilize the flow state of the water flow and improve the cavitation and cavitation damage of the spillway. However, it is still difficult to solve the safety threat to the flood tunnel due to the unfavorable water flow pattern caused by the hydraulic jump in the cave and the accumulation of air bags caused by the flooding of the flood tunnel outlet.

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