Research On Two-Stage Overload Relief Valve And Its Test System For Hydraulic Support

As the development of the economy,the society for coal demand will be bigger and bigger,Hydraulic support as coal mining mechanization is an important equipment.Its work reliability is very important for safe production.The relief valve is an important element in the hydraulic support system.Its performance which is good or bad will directly affect the reliability of the hydraulic support.Therefore,how to design a relief valve which has good dynamic characteristics and large flow will be the focus research in the future for the designers.Firstly this paper is according to the theory which is based on the traditional overflow valve design.According to the structure of the two-stage overload protection safety valve,we design an two-stage overload protection safety valve which has slide valve straight moving type structure and differential type structure and design the main size of the valve according to the design principle.Secondly according to the work principle of the two-stage overload protection safety valve,we create its mathematical modeling and establish the relief valve simulation model with AMESim.We get the dynamic characteristic of the relief valve.By changing the dead zone,impact flow rate,jet mouth diameter,valve core quality,damping coefficient,differential area,spring stiffness of the valve,we can find influence law that the main structure parameters have on the dynamic characteristics of the two-stage overload protection safety valve.Thirdly,we use Proe to create the flow channel mode of the two-stage overload protection safety valve and use GAMBIT to divide the three dimensional flow passage grid and to set boundary conditions.We use Fluent to simulate the three dimensional flow passage and can get pressure map,speed nephogram,velocity vector diagram.We can find the place where can happen vortex,gas hole,cavitation.Finally,because domestic has less large flow valve test system,our country can not get international recognition of the production of large flow valve.According to the working principle of the relief valve and its hydraulic test system,we choose the main component of the system.According to the working principle of the hydraulic system,we use AMESim to model the hydraulic system and can get the dynamic characteristic of the relief valve.By changing the accumulator volume,inflation pressure and the pass fluid flow of the switch valve,we can find influence law that the main structure parameters have on the dynamic characteristics of the two-stage overload protection safety valve.It laid the theoretical basis of the relief valve impact test system optimization design.