| The regulating valve has the function of regulating pressure and flow,and is a very important control element in modern automated industrial production.At present,industrial production has higher and higher requirements for valves.Under special working conditions such as high temperature and high pressure difference,cavitation often occurs inside the valve,which can also cause problems such as vibration and noise.Therefore,in order to ensure the normal operation of the valve and the entire system,it is of great significance to study the mechanism of cavitation inside the valve and the method of suppressing cavitation.This paper uses a combination of numerical simulation and experiment to study the influence of the structural parameters of the throttle orifice plates on its cavitation characteristics.The main research contents and conclusions are as follows:(1)Aiming at the single-stage orifice plate,the method of combining numerical simulation and experimental research is used to study the influence of the basic structure characteristics of the orifice on the flow characteristics and cavitation characteristics.Firstly,the influence of the opening form on the flow characteristics and cavitation characteristics of the throttle orifice plates is analyzed,and the experimental research on the typical structure of the orifice is carried out;Then the influence of the aperture on the flow capacity and anti-cavitation performance of the throttle orifice plates is analyzed: the larger the ratio of the aperture to the pipe diameter,the stronger the flow capacity per unit area;Finally,the influence of the length of the throttling orifice straight section on its flow characteristics and cavitation characteristics is studied,and it is shown that extending the thru section length can improve the flow capacity of the throttling orifice plate,but its anti-cavitation ability is greatly reduced.(2)Based on the principle of multi-stage pressure reduction,a multi-channel and multi-stage orifice plate is designed,and the influence of the arrangement of the aperture,the ratio of the aperture to the tube diameter,and the step spacing on the flow characteristics of the orifice is studied using simulation and experimental methods.First,the simulation technology is used to study the influence of the aperture arrangement,the ratio of aperture to tube diameter,and the step spacing on the flow characteristics of the orifice plate.Furthermore,a 15-hole multi-stage orifice plate with high flow capacity and a 6-hole multi-stage orifice plate with high cavitation resistance are designed.The test and simulation data show that by optimizing the opening form of the orifice,shortening the length of the straight section of the orifice and reducing the ratio of the hole diameter to the pipe diameter can improve the anti-cavitation performance of the orifice plate.(3)Aiming at the typical labyrinth flow channel,the influence of factors such as the number of depressurization stages,the number of flow channels,and the length between the turns of the flow channel on its flow characteristics and cavitation characteristics are studied.Analyzed the influence law of the depressurization series on the flow characteristics of the labyrinth flow channel,the results show that the higher the depressurization series of the labyrinth flow channel,the stronger its anti-cavitation ability,but the flow capacity will decrease accordingly;Within the scope of the study,increasing the number of runners will increase the overall circulation capacity,while its anti-cavitation ability has not been found to be significantly reduced;The length of the flow channel between the two turns of the labyrinth flow channel increases,and the flow capacity increases,but the anti-cavitation ability will decrease. |
PDF Full Text Request