Research And Application On Control Technology Of Advancing Support With Pressure For Hydraulic Support

As the main safety support equipment for coal mining enterprises to build high-yield and efficient comprehensive mechanized working face,hydraulic support creates favorable conditions for coal mining safety,efficiency and high-yield production.For the unstable or fragile roof,the roof is prone to instability during the short cycle of hydraulic support down-shift-lift and because of repeated support for the roof,the roof is accelerated to break,which is easy to lead to safety accidents.In order to reduce the subsidence speed of the roof and prevent the broken roof from falling prematurely,this thesis studies the control technology of the advancing support with pressure for hydraulic support,taking the shield hydraulic support as the research object,in combination with the coal seam occurrence condition and the actual application demand of the working face.Firstly,combining with the coal seam occurrence condition of working face 4101 in Yangjiacun coal mine,this thesis analyzes the movement characteristics and movement law of the roof of working face,calculates the first caving step distance of direct roof,the first weighting step distance and periodic weighting step distance of basic roof,and determines the overall scheme of the control technology of the advancing support with pressure based on the analysis of the performance requirements of the control mode of the moving frame with pressure;Secondly,the mechanical characteristics of the hydraulic support are analyzed in the process of advancing support with pressure,and the range of the residual support force of the col bottom cavity of pillar jack is determined.Based on the mechanical calculation of the whole support,the finite element analysis and the fatigue analysis of the pillar jack are carried out for the hydraulic support under the condition of advancing support with pressure;Then,the main hydraulic system of working face and control system of advancing support with pressure for ZY12000/28/63 hydraulic support are designed,which mainly includes the optimization design of hydraulic support pillar jack control circuit and pushing jack control circuit,and the simulation model of control circuit is established by using the hydraulic simulation software AMESim according to the designed control circuit of advancing support with pressure.The main control circuit is simulated,and the flow curve,velocity curve and acceleration curve of each circuit are obtained to ensure the correctness of the hydraulic system design of the hydraulic support;Finally,the field application test was carried out on the two-pillar jack shielded hydraulic support of ZY 12000/28/63 in Yangjiacun Coal Mine.Through the test analysis and field application,the feasibility and stability of the control technology of the advancing support with pressure for hydraulic support are verified.Through the research,simulation and test application of the control technology of advancing support with pressure for hydraulic support,it shows that the method of advancing support with pressure can not only realize the hydraulic support always supporting the roof,reduce the subsidence speed of the roof,prevent the broken roof from falling prematurely,adapt to the unstable roof conditions,but also save the process of column falling and rising,improve the moving speed and reduce resistance increasing time.In the face with large inclination angle,it can also prevent the support from sliding down in the process of advancing to the coal wall.Therefore,the advancing support with pressure is an ideal way to maintain the stability of the roof and the hydraulic support of the working face,and it is an effective way to improve the safety and efficient production of the comprehensive mechanized working face.