Simulation Research On Transient Flow Field And Vortex-induced Vibration Of High Pressure Drop Labyrinth-sleeve Control Valve

This paper was completed under the support of the National Natural Science Foundation of China(No.51569012).When a single-seat control valve is operated under high-pressure differential conditions,severe pressure pulsations and vortices can easily lead to vortex-induced vibration fatigue damage of the control valve piping system,and generate large noise,which seriously affects the safe operation of pipeline system equipment and physical-mental health of operators.In view of the deficiencies of the single-seat control valve,based on a large number of investigations,the high pressure drop labyrinth-sleeve control valve was designed.Moreover,simulation researches of three-dimensional transient flow and vortex-induced vibration were separately performed for three typical throttling models of the valve under maximum,normal and minimum conditions.The following works were carried out concretely:(1)The research status of the flow field of the control valve and the vortex-induced vibration at home and abroad were investigated.The vibration noise and damage failure of the single-seat control valve working under high pressure differential conditions were analyzed,and the significance of the study of the high pressure drop labyrinth-sleeve control valve further was summed up.(2)Aiming at the large differential pressure condition of the control valve,high-pressure drop labyrinth-sleeve control valve that satisfies equal percentage flow characteristics was designed by combination of six-channel labyrinth discs,four-channel labyrinth discs and multi-stage sleeves.The labyrinth disc can not only achieve the function of the fluid pressure rapid dropped first and then decreased,but also can effectively avoid the large pressure recovery at the last stage of the flow channel.The multi-stage sleeve structure can achieve the purpose of silencing and vibration reduction.(3)The ANSYS Fluent software was used to study the flow adjusting characteristics of the high pressure drop labyrinth-sleeve control valve,and its three-segment equal percentage flow characteristic curve was obtained.Three-dimensional transient flow simulations of three typical throttle models of the control valves were completed for maximum,normal,and minimum conditions.The fluid flow characteristics and pressure pulsation characteristics were studied,and the relationships were obtained among operating pressure drop,throttle opening,and fluid pressure pulsation.(4)Using the ANSYS Workbench software,the flow field,static field and modal analysis modules were combined to establish fluid-structure coupled modal analysis models in the three typical throttle openings of the high pressure drop labyrinth-sleeve control valve respectively under the maximum,normal and minimum conditions.The first six modes of the valve were solved,and the relationships among pressure drop under different conditions,throttle opening,mode order and modal frequency of the valve were obtained.In addition,frequency spectrum analysis of time domain information of lift coefficient calculated from the transient flow field of the control valve was performed,and the main frequency range of vortex shedding was obtained.Comparing the natural frequency of the valve with the main frequency of vortex shedding,it can be concluded that the vortex-induced vibration locking phenomenon does not occur for the control valve.By the above research,it provides a new idea for the structural design of the vibration reduction and noise reduction internals of high-pressure drop valves,and provides a reference for the study of locking phenomenon of vortex-induced vibration of the control valve.