Study On The Prevention And Control Of Rock Burst By Hydraulic Support With Large Flow Safety Valve

Rock burst is one of the most serious disasters in coal mines,and the anti scouring support system is the last line of defense to protect underground equipment and personnel when the rock burst occurs.The key of the application of the anti erosion support system in the coal mine is whether the safety valve can realize rapid and large discharge pressure relief.At present,the domestic safety valve can not meet the requirements of rapid unloading when the rock burst occurs,resulting in serious damage to the hydraulic column.Therefore,it is of great significance to design and develop a safety valve which can meet the requirements of rapid and large discharge pressure relief.The related research work mainly includes the following aspects:(1)Analysis of the large flow safety valve to discharge Herang pressure in the hydraulic support system,safety valve maximum flow stage of coal mine hydraulic support application for 1000L/min,rockburst occurs when the unloading capacity does not meet the requirements.The damage caused by the hydraulic support,the hydraulic support support and the hydraulic support of the portal type tunnel are described.Therefore,a new type of fast and large flow safety valve has been developed.The maximum instantaneous unloading flow rate can reach 4000L/min.(2)Through the analysis of the structure and working principle of the new structure of large flow safety valve,the mechanical model and the dynamic mathematical model of high flow safety valve system,function analysis of transfer function and the block diagram of the system transfer application.The simulation results show that the stability time of large flow safety valve is 15ms,and the maximum unloading flow is 4200L/min.The mechanical model accords with the actual working condition.(3)The internal flow passage of large flow relief valve was simplified,and its three-dimensional geometric model was established.The internal flow path is simulated.With the increase of the opening,the total liquid pressure in the large flow relief valve gradually decreases,and the unloading flow increases gradually to achieve the purpose of unloading.The pressure at different inlet is studied,and the change of pressure and velocity is mainly around the unloading hole.With the increase of inlet pressure,the maximum velocity at the unloading hole increases.(4)The large flow safety valve system is simplified as a damped mass spring mass system.Analysis its dynamic characteristics in AMESim.Through the research and analysis,it can be seen that reducing the number or diameter of the damping holes can alleviate the oscillation in the opening process.Increasing the spring stiffness can improve the stability;reducing the quality of the spool and spring can improve sensitivity.(5)The safety valve with large flow impact experiments,simulation of rockburst conditions of large flow safety valve discharge pressure and load changes,the rock burst occurs when large flow can be quickly unloaded,traffic reached 3500L/min.Compared with the numerical simulation results,due to the neglect of some complicated factors,the numerical simulation results in some errors.In the engineering practice,the large flow safety valve is monitored,and the impact unloading function of the large flow safety valve in practice is analyzed.