A new type of tailrace tunnel ventilation hole structure

Abstract

The invention discloses a novel tailwater tunnel ventilation hole structure, which comprises a ventilation hole, a movable baffle, a movable connecting rod, a spring, a buffer device, an annular anti-slip block and a card slot. The ventilation hole is a two-way ventilation hole. When there is negative pressure in the tailwater tunnel, the gas enters the ventilation hole from the outside, and the airflow will push up the movable baffle, and the movable baffle will drive the movable connecting rod to move obliquely upward. The baffle is fully opened, the air intake area reaches the maximum, and the air supply speed is fast, which can relieve the negative pressure of the tailrace tunnel in time; when the tailrace tunnel is exhausted, the pressure of the reverse airflow will make the movable baffle move obliquely downward , the movable baffle is engaged with the card slot, the vent hole is tightly closed, and the airflow is discharged from the round hole reserved on the movable baffle, and the exhaust speed is relatively slow, which greatly reduces the transient pressure when the air mass is discharged from the orifice. On the premise of satisfying other safety and reliability performance requirements, the invention can greatly alleviate the negative pressure in the tunnel during air intake and the impact pressure during exhaust, especially for tailwater tunnels of hydropower stations and urban pipe networks, and the effect is remarkable.

Description

technical field [0001] The invention relates to the technical field of water conservancy and hydropower engineering, in particular to a novel tailwater tunnel ventilation hole structure, which is suitable for hydropower station tailwater tunnels and urban pipe networks. Background technique [0002] In the early stage of the construction of a large-scale diversion-type hydropower station, a large-scale construction diversion tunnel is required, and the design often combines the construction diversion tunnel with the tail water system of the hydropower station. In the later stage of the project, part of the diversion tunnel is converted into a power generation tail water tunnel. When the water level of the downstream cascade reservoirs is close to the top of the tunnel, the initial pressure in the tailrace tunnel is small. When the power station transitions, the pressure and surge in the tailrace change drastically, which may lead to the tailrace tunnel at a higher position. ...

AI Technical Summary

Problems solved by technology

In the current design, the air hole area of ​​a fixed size is basically used, and the contradiction between the minimum negative pressure and the maximum positive pressure cannot be well balanced. The present invention uses a new air hole form, which is well coordinated Minimum negative pressure and instantaneous maximum positive pressure of tailrace tunnel

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