Air supplementing system of high-velocity flow tunnel and ventilating capacity control method thereof

Abstract

The invention provides an air supplementing system of a high-velocity flow tunnel and a ventilating capacity control method thereof. The air supplementing system comprises a water aeration mitigationcavitation air supplementing facility, and an air supplementing facility which is dragged by high-velocity flow to take away air, wherein the water aeration mitigation cavitation air supplementing facility, and the air supplementing facility which is dragged by high-velocity flow to take away air are separated from each other and correspondingly communicate with outside atmosphere through relatedspecial air supplementing holes or air supplementing wells; the section area Ac of a hole top air supplementing channel of the air supplementing facility which is dragged by high-velocity flow to takeaway air is (18%-33%).Qw/Vc; if the air velocity of the hole top air supplementing channel is beyond a threshold value, a gate and a structure are easy to vibrate and generate harmful squeal, thus the section area Ac of the hole top air supplementing channel is to be adjusted until the air velocity is less than the threshold. With the adoption of the system, the water aeration mitigation cavitation effect of the high-velocity flow tunnel can be ensured, and the gate and structure can be effectively prevented from vibration and harmful squeal.

Description

technical field [0001] The present invention relates to a ventilation and air supply system of a drainage tunnel and a ventilation volume control method thereof, in particular to an air supply structure for supplementing the air taken away by the water flow dragged by the water flow and the air required for aeration and corrosion reduction in a high-speed water flow tunnel, and the air supply structure in the design The air flow control method is applicable to the aeration and corrosion reduction and ventilation and air supplementation of discharge tunnels of water conservancy and hydropower projects. Background technique [0002] The ventilation of high-speed water flow tunnels is the key to the safety of hydraulic tunnels, and has always been concerned by hydraulic experts. Because the high-speed water drags away a large amount of air, it is necessary to replenish air into the cave to avoid excessive vibration and noise; on the other hand, the high-speed water flowing thro...

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Problems solved by technology

When the tunnel flow rate is very high (such as greater than 40m / s), the following problems will affect the safety of the tunnel operation: 1. The high-speed water dragging will take away a lot of air, reducing the air pressure on the top of the tunnel, and the top of the tunnel is basically filled with water vapor mixture. The pressure difference between the roof and the bottom cavity is reduced or disappeared, and it is impossible to inhale enough air, which affects the effect of aeration and corrosion reduction; 2. The calculation of the amount of air dragged away by high-speed water flow, and the supply There is no mature calculation method in the engineering field at present for the influence of gas volume

However, the model test can only measure the amount of aeration and corrosion reduction ventilation, but cannot measure the amount of air dragged away by the high-speed water flow, resulting in insufficient ventilation sections in many high-speed drainage tunnels, and the measured wind speed of the ventilation holes is much higher than that of the model test. Wind speed, the wind speed of some engineering model tests is only 30-40m / s, the measured wind speed reaches 100m / s, and the ventilation volume is much greater than the test value, which not only affects the effect of aeration and corrosion reduction, but also produces harmful vibration and howling, which affects the safe operation of the tunnel

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