Realizing method for improving exhaust capacity of air inlet and exhaust valves

Abstract

The invention discloses a realizing method for improving the exhaust capacity of air inlet and exhaust valves. On the basis of establishment of streamline mathematical models of the air inlet and exhaust valves, as for a water supplying system, the theoretical exhaust quantity is calculated, the types and specifications of the conventional air inlet and exhaust valves are determined, and the exhaust flow coefficients are calculated; and the same specification of the section-variable air inlet and exhaust valves with exhaust flow channels being in a streamline shape are designed, the actual exhaust quantity and the actual exhaust flow coefficients are tested, recorded and calculated on an exhaust performance test platform. Experiments prove that the exhaust capacity of the section-variableair inlet and exhaust valves is obviously improved, thus under the premise of meeting the exhaust requirements, the diameter and the number of the air inlet and exhaust valves can be decreased, investment is lowered, the anti-cavitation performance of inner components is improved, the service life is prolonged, and the pipe-bursting accident caused by improper type selection of the air inlet and exhaust valves is avoided; and the viewpoint that the internal and external pressure differences of the air inlet and exhaust valves are different, and thus the exhaust flow coefficients of the air inlet and exhaust valves are also different is put forward and verified for the first time, the basis is provided for improvement of type selection standards and formulation of production technical standards in the water supply industry in China, and the realizing method is of great significance to ensure safe operation of pipelines.

Description

technical field [0001] The invention belongs to the field of type selection of intake and exhaust valves, and in particular relates to a method for improving the exhaust capacity of the intake and exhaust valves. Background technique [0002] The research on intake and exhaust valves began around the 1560s. In recent years, scholars at home and abroad have done in-depth research on the mathematical model, protection effect, characteristic parameters and selection rules of intake and exhaust valves. A large number of studies have shown that correct Proper design, selection and installation of intake and exhaust valves is one of the effective solutions to ensure the initial filling of long-distance water pipelines and sufficient intake and exhaust during emergency shutdowns. The intake and exhaust valves have the advantages of simple structure, low cost, convenient installation, and are not restricted by installation conditions. The current common intake and exhaust valves in ...

AI Technical Summary

Problems solved by technology

[0008] like figure 1 and figure 2 As shown, the valve body of the traditional intake and exhaust valve design is cylindrical. After the air in the pipe flows into the valve body, the air and the boundary are often separated and a vortex is generated. Exchange with energy, and consume a large amount of mechanical energy through friction and violent collision between mass and particle, which reduces the efficiency of intake and exhaust, the air in the pipe cannot be discharged in time, and the negative pressure in the pipe cannot be destroyed in time, which has a greater impact on the safe operation of the water pipeline. In addition, when the negative pressure is generated in the pipe, the floating ball action of the intake and exhaust valves will inevitably be delayed, and the cavitation problem of the conventional flow channel will also occur from time to time. action, seriously endangering the safety of the project

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