Study On Compressible Flow And Acoustic Characteristics Of High Temperature Steam Pressure Reducing Valve

China is the largest valve manufacturer in the world.However,due to the lack of basic theoretical research,design means and industry accumulation time,China’s highend valves rely heavily on imports.In order to promote the localization process of high-end valves and improve the level of valve manufacturing industry in China,this paper studies the compressible flow and noise inside the high-temperature steam pressure reducing valve based on the research project of valve localization in power plant.The main research work of this paper is as follows:(1)The research status of high temperature steam pressure reducing valve at home and abroad is investigated.It is clear that the throttling flow and flow induced sound of compressible fluid are the research difficulties of high temperature steam pressure reducing valve.Therefore,a hybrid calculation method of computational fluid dynamics(CFD)and computational aeroacoustics(CA)is proposed to study the compressible flow and acoustic characteristics of high temperature steam pressure reducing valve.(2)A valve noise test-bed was set up to measure the influence of a series of factors such as the nominal diameter of the valve,the opening height,the pressure difference between the front and the back of the valve,and the position of the noise monitoring point on the noise of the valve.On the basis of experimental measurement,the noise field caused by gate valve leakage is simulated,and the reliability of numerical simulation method is verified.The results show that the error between the noise of numerical simulation and the measured value is between 6% and 16% under different conditions.(3)Based on the analysis and discussion of the throttling principle of steam pressure reducing valve,a new structure of high temperature steam pressure reducing valve is proposed.By using FLUENT software,the flow pattern in the steam pressure reducing valve is realized under the conditions of actual steam gas model,complex structure and unsteady flow field.The physical fields such as pressure,velocity,temperature,turbulent dissipation rate and Mach number are analyzed.(4)On the basis of fluent flow field calculation,the acoustic finite element method of LMS virtual.Lab is used to study the acoustic characteristics of high temperature steam pressure reducing valve,and the noise radiation of high temperature steam pressure reducing valve is calculated.The FW-H method is used to obtain the sound pressure response curve of the working noise of the high temperature steam pressure reducing valve.(5)According to the analysis results of the compressible flow of the high temperature steam pressure reducing valve,the structure of the valve is optimized,four types of choke rings are put forward,and the flow field and sound field are analyzed and compared,and the diversion effect of the choke ring on the internal turbulence of the high temperature steam pressure reducing valve and the influence on the parameters of the flow field are discussed.