Study On Rapid Method Of Large Flow Safety Valve:Gas Explotions And Accumulators Combination Loads

Power support is the key part of the underground compound mining equipment,and the relief valve as one of the support in fully mechanized coal mining face three control elements,mainly play a protective role in support of overload protection,the dynamic and static performance directly affects the safety of fully mining process.The existing large flow relief valve has reached more than thousand upgrade,but the test device for the relief of dynamic and static performance is not perfect enough,especially in the research of dynamic performance.Therefore,in order to reduce the damage of the impact load on the hydraulic support,it is very important to design a system which can meet the comprehensive test of safety valve.Based on the fully mechanized mining face,this article analyzed the basic roof rotary caving process of the load produced by hydraulic support,deduced the hydraulic support column by using static and dynamic load,utilize the parameters of Bulianta 22303 working face and of the ZY16800/32/70 type bracket to calculate,then the maximum load caused by falling roof collapse is82.04 ?10 N.Then calculate the discipline in the roof caving process of load variation with time,the maximum loading rate of up to 2304MPa/s,and in 0.175 s single column usually loads up to 47 MPa,with the properties of the composite rock beam.According to the study on comparison of large flow relief valve test loading methods in the literature and explosion characteristics in confined space,proposed by way of explosion shock load simulation of hydraulic support,by the preliminary determination of explosion and energy storage test system interaction.Secondly,the explosion process of the explosion cavity by use of CFD software Fluent simulation,after repeated simulation,determine the initial conditions,the simulated explosion pressure,temperature,fluid velocity change trend.It can be through the pressure variation in the explosion process,In 0.012 s,explosive force acts on the pillar is 22.31 MPa,and the accumulator to load up to 53.81 MPa,the maximum loading rate is 3088MPa/s,consistent with theoretical calculation load,and faster than the calculated loading speed,the impact load simulation of roof pressure the explosion loading method is reasonable.Finally,build the explosion and energy storage test machine loading to test large flow valve,to gas ratio by the initial conditions of the simulation process,the safety valve normally open the overflow through the explosion cavity pressure characteristic of pressure sensor,the pressure reaches a maximum of 25.38 MPa at 0.013 s,and pressure 48.99 MPa storage,the maximum loading rate is 3262MPa/s,consistent with the simulation results.Therefore,through the above calculation,simulation analysis and experimental data comparison,explosion and energy storage device load loading mode is more close to the roof pressure of hydraulic support in the process of bear,can satisfy the static and dynamic performance test of safety valve.