Long wind pipe uniform wind sending and returning method and device thereof

Abstract

The invention relates to a method and a device which are used for leading a long wind pipe to uniformly send and return the wind. The proportional cross-section area size of the rated shunt air quantity of each step of bypass branch pipes is calculated according to the quantity of the three-way wind valves arranged on the long wind pipe and the cross-section area size of the total wind pipe of the initial three-way wind valve; furthermore, the proportional cross-section area size is taken as the basis of the shunting of the wind quantity shunt valve with the shunt adjusting function and the gradual contraction quantity of the cross-section area size of all levels of valves; therefore, leading the wind speed and the dynamic pressure in the long wind pipe to trend to be consistent and the wind-obtaining quantity of all bypass branch pipes to trend to be close, and achieving the object of uniformly sending and returning the wind by the long wind pipe. The device consists of a long wind pipe and bypass branch pipes; the long wind pipe is connected by a plurality of wind quantity shunt three-way adjusting valves or modified three-way wind valves which have the function of shunt adjustment, ensure the airflow speed and the dynamic pressure in the long wind pipe to be approximate to each other and lead all bypass branch pipes to obtain the basically approximate airflow wind quantity. The method is reliable, the device has scientific and reasonable structure, the difficult problem that the existing long wind pipe can not realize the uniform sending and returning of the wind for a long time is solved, and the method and the device have extremely strong practicability.

Description

technical field [0001] The invention relates to the technical field of air volume adjustment, in particular to a method and a device for uniformly sending and returning air from long air pipes in subways or building environmental control systems and air-conditioning ventilation systems. Background technique [0002] At present, long air ducts are used to send and return air in the environmental control system of subways or buildings and in air conditioning and ventilation systems. The long air duct is composed of several main air ducts, straight-through branch pipe interfaces and bypass branch pipe interfaces, such as figure 1 As shown, the traditional long air duct is composed of several three-ventilation valve bodies with the same structure and shape. The valve body is composed of interconnected main air ducts and straight branch pipe interfaces. The flow direction is related to the pressure and suction inside the branch pipe. The air volume driven by the external pressur...

AI Technical Summary

Problems solved by technology

The long air duct is composed of several main air ducts, straight-through branch pipe interfaces and bypass branch pipe interfaces, such as figure 1 As shown, the traditional long air duct is composed of several three-ventilation valve bodies with the same structure and shape. The valve body is composed of interconnected main air ducts and straight branch pipe interfaces. The flow direction is related to the pressure and suction inside the branch pipe. The air volume driven by the external pressure usually moves in a straight line when there is no external force interference on the way, thus causing most of the air flow to flow straight through the branch pipe, and only a very small part The air volume of the air flow turns to the bypass branch pipe under the action of the internal static pressure on the bypass branch pipe, and since there is no air distribution control device inside the valve body, even if the static pressure in each bypass branch pipe is the same, when entering When the air volume dynamic pressure of the air flow is large, the air volume of the bypass branch near the tail end is often greater than that of the bypass branch near the front end, and when the dynamic pressure of the incoming air volume is small, the bypass branch near the front end is often The air volume of the bypass pipe is greater than that of the bypass pipe near the tail end. Therefore, the air volume of each bypass pipe in the long air duct of this traditional structure is not uniform, so it cannot meet the actual use requirements.

In order to improve the uneven air volume of each bypass branch pipe in the long air duct, the industry has actively explored, and in recent years the following three structural improvement measures have appeared: one as figure 2 As shown, while keeping the cross-sectional area of ​​the bypass branch pipe interface constant, the size of the cross-sectional area of ​​the valve body composed of the main air pipe and the straight-through branch pipe on the three-ventilation valve is gradually reduced to maintain the airflow velocity and airflow in the long air pipe. The flow pressure is basically unchanged, so as to ensure that the bypass branch pipes of each stage can obtain a basically similar airflow volume, but in practice, it is found that the dynamic pressure of the air will be automatically converted into static pressure when it is close to the bypass branch pipe interface of several stages at the end , so the purpose of sending and returning air evenly cannot be achieved; the other is as image 3 As shown, on the basis of keeping the cross-sectional area of ​​the long air duct basically unchanged, the cross-sectional area of ​​the bypass branch pipe interface is gradually increased. The purpose is to overcome the dynamic pressure of the air flow in the long air duct. The smaller the weak point, the method of gradually increasing the cross-sectional area of ​​the bypass branch pipe interface can ensure that the air intake and return air volume of each bypass branch pipe is basically similar. In fact, it is difficult to control, and it is very difficult to realize, and the material input and processing costs of the long air duct of this structure are very high, so the operability and economy are poor; the third is as follows: Figure 4 As shown, a regulating valve is added to the interface of each bypass branch pipe at each stage, and the method of controlling the opening of the valve is adopted step by step during work to make the air volume of each bypass branch pipe tend to be similar, but in practice it is found that , because the adjustment of the air volume of any regulating valve will lead to the change of the total pressure in the long air pipe, which will affect the air volume of other bypass pipes that have been adjusted or have not been adjusted, so not only waste time and power during operation, but also It is also difficult to achieve the purpose of evenly sending and returning air

It can be seen from the above that the inability to achieve uniform air supply and return is a major problem that has existed for a long time in the long-term air duct supply and return work process of the existing structural form, which seriously affects the working quality of the building environmental control system and air conditioning ventilation system , it is necessary to study and overcome

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