Research On Aerodynamic Noise Characteristics And Multi-objective Standard Optimization Of Porous Sleeve Steam Regulation

Control valve as a common control element in the pipeline system,with the function of regulating pressure and throttling,widely used in nuclear power and other fields,plays an important role in the safe and stable operation of the pipeline system.As the production scale of China’s highparameter nuclear power construction continues to expand,the demand for regulating valves continues to expand,the regulating valves face increasingly severe working parameters,especially for steam regulating valves.In high temperature and pressure,high flow rate and other extreme conditions,the degree of fluid oscillation intensified,the complex flow state in the regulating valve,resulting in unstable flow of the internal flow field of the valve,thus easily triggering pneumatic noise,which adversely affects the normal and stable operation of the equipment.Throttle sleeve as a key control valve flow characteristics of the valve inside the valve,to ensure that the regulating valve regulating the basic function of throttling.The porous sleeve control valve has good noise suppression performance,and it reduces the pneumatic noise of the control valve from the root by improving the traditional throttle window type sleeve.Therefore,the porous sleeve in this type of control valve,both to ensure the flow capacity of the control valve,but also to control the pneumatic noise characteristics of the key.However,there are still many shortcomings in domestic steam control valves,and the design technology of key core components is still restricted by foreign countries.To this end,this paper focuses on a large-diameter high-parameter porous sleeve steam control valve and carries out structural design research on porous sleeve steam control valve,comprehensive analysis of its flow characteristics,pneumatic noise characteristics and noise reduction optimization of the control valve structure,the specific research content is as follows.(1)In order to improve the noise suppression performance,based on the multi-stage noise reduction principle,the two-stage sleeve is designed on the basis of the original single-stage throttling sleeve: the desired flow coefficient under each opening degree is obtained by designing the flow characteristic curve through the working parameters of the regulating valve,and the desired flow coefficient is designed through the sleeve throttling orifice parameters to ensure the flow characteristics of the regulating valve and obtain the single-stage and two-stage sleeve with the same flow characteristics.In the process of design,a smooth and continuous two-stage flow characteristic curve design method is proposed to improve the flexibility of selecting the flow characteristic curve of the regulating valve;to address the existing theoretical model for calculating the flow area of the regulating valve sleeve is not applicable to the problem of multi-hole sleeve,an error compensation design method is proposed and verified through simulation and experiment that the method can effectively ensure that the flow characteristics of the regulating valve meet design expectations(2)Establish a steady transient simulation model of compressible flow,and use saturated steam as the working medium to study the flow characteristics and pneumatic noise characteristics of singlestage and two-stage sleeves with the same flow characteristics,analyze the Mach number distribution,sound power level,and the sound pressure level spectrum and total sound pressure level at different openings,and determine the main sources of noise in the control valve.The impact of the noise suppression performance of the control valve.(3)In order to ensure that the flow characteristics of the original control valve remain unchanged,a multi-objective optimization of the small opening two-stage sleeve steam control valve is performed by designing the sample space with the throttle diameter,the number of holes and the ratio of inner and outer hole diameters for 10 and 20 openings,sampling the sample space by combining genetic algorithm improved Latin hypercube sampling and adaptive sampling,LM-BP neural network The Pareto solution set is obtained by the multi-objective genetic algorithm NSGA-II,and the optimized structural parameters are finally compared and validated by simulation.