Simulation Analysis Of Prop Pilot Operated Check Valve And Research On Visualization Of Flow Field

Pilot operated check valve is one of the key components of the hydraulic support, its performance is the important guarantee for the performance of the hydraulic support work. In the course of the uninstall, Pilot operated check valve regular occurs uninstall impact. Severe pressure impact not only affect the reliability of Pilot operated check valve, will also affect the life of pipes, fittings and safety valve of system components, may cause the bracket column, components damage and even raise a security incident when serious. analyzing the performance of hydraulic control valves, uninstall impact factors, as well as on the internal structure of the valve, inner pressure of valve road, liquid velocity and cavitation analysis, there will be of far-reaching significance to improve the performance of hydraulic-controlled check valve, prolong service life, thereby improve the performance of key parts and whole machine of hydraulic support. This paper took the column Pilot operated check valve for a study, providing reference to actual production application.By creating valve force equilibrium equations of column Pilot operated check valve and establishing valve flow equations, and flow continuity equation, analyzed the dynamic characteristic of hydraulic control check valve.Applicating AMESim software established and simulated column Pilot operated check valve opening pressure test, the reverse open control pressure test, unload simulation models. Come to the following conclusions:(1) when pressure is0.26MPa, valve core opens.(2) when controlling pressure is2.63MPa, the small valve core opens, control valve core opens when the pressure is 24.12MPa.(3) the pilot operated check valve existed pressure shocks during the uninstall process. Basised on analysis of Pilot operated check valve pressure impact mechanism of unloading, by changing parameters of the hydraulic damping hole diameter, cone angle valve, column diameter, load size, emulsifying liquid volume elastic modulus, liquid supply pipe diameter, Drew related factors of affecting unloading impact of column Pilot operated check valve. Through the simulation concluded that:hydraulic damping hole diameter, cone angle valve, column, liquid supply pipe diameter, top beam diameter and column stiffness on column uninstall impact significantly. Among them, the damping hole diameters of hydraulic control at the best value is1mm; the bigger valve cone angle, the less number of valve opening and closing times and the pressure impact times during uninstall; the bigger liquid supply pipe diameter, the less uninstall impact, the smaller valve core vibration frequency, closing phenomena of valve core did not happen; the smaller stiffness of beam and column, the greater uninstall impact pressure, greater stiffness and less uninstall impact.Applicating FLUENT software simulated the flow field of hydraulic control valves with different half-cone angles valve core, different seating structures, and different open volume, obtained fluid flow under different conditions, come to the following conclusions:(1) the larger the half cone angle of the valve core, the smaller distribution of maximum speed of throttle mouth place, maximum speed reduced, increasing the half cone angle, high speed liquid momentum changes reduced during valve port closed when unloading, in favour of reducing hydraulic shock. The larger half cone angle, the smaller vortex formed at the corner of throttle, the smaller low pressure area, susceptible to cavitation region reduced.(2) the seat structure with face contact can ease the pressure mutations of the throttle, pressure gradient changes were smaller at throttle mouth, the area of low pressure formed was smaller, not easy to form air pockets; liquids flow more quietly at the valve port, less impact to valve wall formation, with smaller energy loss.(3) the greater degree of valve opening, the smaller valve core throttle mouth place maximum speed, the smaller maximum velocity area distributing outlet of the throttle, can help to reduce the impact of Pilot operated check valve during the uninstall process.The research work of this paper provided reference information for hydraulic one-way valve design, related key parts of support design and manufacture and selection, the methods of modeling and simulating involved in paper also can provide reference for the study on the dynamic characteristic of hydraulic system.