Analysis Of Noise Mechanism Of Flow Control Valve

The HVAC system in the building control system is a general term for the heating system,ventilation system and air conditioning system in a building,and it is an important part of the entire building.With the development of urbanization,large-scale commercial buildings or office buildings have adopted advanced HVAC systems.In HVAC systems,the on-site equipment-regulating valves used to control the flow of refrigerants or heat media,under certain operating conditions,which can produce noise that is harmful to people’s health and affect people’s work and life.Valve noise will increase the load of the pipeline system while affecting people’s physical and mental health,and even cause the collapse of the pipeline system,causing great losses.Taking the flow regulating valve used in the HVAC system as the research object,on the one hand,the simulation software is used to analyze the internal flow field of the valve and the valve structure mode to explore the noise mechanism of the flow regulating valve.On the other hand,through a large number of noise test experiments,the frequency components of the noise are analyzed.Main tasks are as follows:The structure and principle of the HVAC system are described,the role of the flow regulating valve in the system is clarified,the structural characteristics of the regulating valve used for water are analyzed,and the basic structure of the two flow regulating valves used in this study are given.Through the computational fluid dynamics software Flo EFD,the internal structure of the flow control valve under different working conditions was analyzed,and the speed and pressure distribution of the flow control valve under different working conditions were obtained and analyzed in detail.In the UG software environment,the finite element simulation of the flow control valve was carried out to obtain the natural frequency and vibration mode of the free mode and constrained mode of the flow control valve.Through the sound sensor,data acquisition card and corresponding computerhardware,a noise test system based on the idea of virtual instrument was constructed,which lays the foundation for further experimental research.Based on the flow characteristic test of the flow regulating valve,the noise test system was used to complete the noise test of the valve under various working conditions,and the noise spectrum of the two types of valves was analyzed in detail.In addition,the analysis of the noise characteristics under various fine-tuning of the valve structure has been completed.