Simulation On Dynamic And Flow Field Characteristics Of Large Flow Electro-hydraulic Directional Valve

Hydraulic support is the important supporting device used in coal mining face,with the coal winning machine and scraper conveyor, achieve modernization coal mine fully mechanized working together.In order to improve the production, modern fully mechanized technology adopted high-power shearer and large capacity of scraper conveyor, to give full play to its efficiency, it is necessary to improve and supporting the use of hydraulic support moving speed, supporting operation to shorten the time and achieve high production and efficiency of fully mechanized requirements;With the increase of mining height are broken, the diameter of the pillars and height also increases accordingly, the large flow electro-hydraulic directional control valve, rated flow only 400 l/min, so can’t meet the requirement of fast moving frame supporting operation, shorten the time.Bracket, therefore, need to develop in the direction of high pressure large flow and the electro-hydraulic control, to adapt to the requirement of modern coal mine fully mechanized.This paper designed a big flow electro-hydraulic directional control valve, the rated flow of 1000 l/min, the rated pressure of 31.5MPa, and analyses the structurecharacteristics and the reversing mechanism, by studying the force of the valve core, it is concluded that the commutation process and structure parameters of the mathematical model, then using the system dynamic simulation software AMESim modeling to dynamic characteristics of electro-hydraulic directional control valve system is emulated, and the use of ANSYS workbench software key element of the reversing valve dynamics simulation, then with the help of fluid simulation software Fluent, the body internal flow field simulation, finally, the performance of the designed valve was tested.Using AMESim software for reversing valve system simulation, obtained the valve outlet pressure and outlet flow dynamic characteristics.The results show that the valve core start takes 0.9s, and the smooth movement, good dynamic characteristics.In addition, in view of other structural parameters influencing the dynamic characteristics of the directional control valve, such as stroke of valve core and the spring pressure,etc, choose the best value.Using ANSYS workbench software of finite element analysis was carried out on the key components of the directional control valve, two conditions for open and close the valve core, checking the strength of the key components, and the valve core radial fluid hole produced maximum stress, finally the structure optimization.Using the computational fluid dynamics software Fluent to simulate the reversing valve interior flow field, the flow field characteristics of body internal flow channel.The results showed that with the increase of open valve core displacement, the flow field in the vortex intensity and coverage is reduced, oil inlet velocity decreases,and maximum speed area appeared in the downstream of the valve position.The large flow valve test bench for the design of directional valve was tested.Experimental results show that the flow rate of 750l/min experimental conditions, the valve core to complete opening and closing action within 1 s, reliable operation, flexible motion, dynamic characteristic indexes meet the design requirements;The test pressure of 4MPa and 31.5MPa, all show a good sealing performance, realize the development goals.For the development of the same kind of valve laid a certain foundation.