Research On Coal Loading Performance And Parametric Simulation Of Double Drum Sheare

The double-drum shearer is the main equipment for underground long-wall coal mining.As the main working part of the shearer,the spiral drum accounts for more than 80% of the total installed power of the shearer.Its cutting efficiency,coal-loading efficiency are important indicators for evaluating the performance of the coal mining machine.The coal loading analysis of the spiral drum can check whether its coal loading performance meets the design requirements.Common methods include underground test,coal and rock cutting test bench,and computer simulation.Among the three,the coal loading simulation by discrete element can be inspected on the design stage,which has the advantage of low cost and short time.In order to study the coal loading performance of the front and rear drums of different shearers under the conditions of forward and reverse rotation,under the guidance of the theory of spiral drum coal loading,discrete element software was used to simulate the mechanical properties of coal and rock mass and the process of drum loading,and Python language was used to write drum movement,coal loading and post-processing programs.Through the simulation program,the motion parameters and structural parameters that affect the coal loading efficiency and over-throwing rate are analyzed,and the variation law of coal loading efficiency is summarized according to the simulation results,and the guidance for the design optimization of the drum shearer is given.The mechanical analysis is carried out on the speed,coal throwing flow and flow moment,and coal capacity of the spiral drum under the condition of coal injection,and the mechanical analysis of the coal capacity space and load in the case of push coal loading,and the influence of the drum structure parameters on the coal loading efficiency is obtained.According to the law of mechanical analysis,the calculation formula of coal loading capacity is deduced.Use discrete element software to simulate single-drum coal loading to verify whether the theoretical model is consistent with the simulation results.The coal loading simulation was carried out by changing the radius of the coal wall particles,and the influence of the particle radius on the accuracy of the simulation results was analyzed.The total time of the simulation program running on different computers was calculated,and the method to improve the simulation efficiency was obtained.The statistical data showed that the average influence factors of particle radius,traction speed,and processor performance on the total simulation time were 4.78,1.85,and 0.46,respectively.On the basis of single-drum coal loading simulation,the front and rear coal walls are composed of 15%,50%,and 35% of particles with 15 mm,20 mm,and 25 mm radius respectively.The structural parameters of the coal baffle can be adjusted according to the size of the actual product model.The simulation and post-processing program of the drum coal loading motion is written in Python language,and the simulation results are output in CSV format to complete the construction of the parametric coal loading model.The parametric coal loading model is used to simulate the coal loading of the MG450/1030-WD and MG200/500-WD shearers.The effects of forward rotation,reverse rotation,traction speed,rotational speed,helix angle,and scraper structure parameters on the coal loading efficiency and over-throwing rate of the front and rear drums of the shearer were studied.The research shows that the coal loading efficiency of the front drum of the shearer is higher than that of the rear drum,the over-throwing rate during reverse rotation is higher than that of forward rotation.The coal loading efficiency of front drum forward rotation is higher than that of reverse rotation,and the coal loading efficiency of rear drum reverse rotation is higher than that of forward rotation.The design of the front drum should follow the principle that the higher the rated speed,the smaller the helix angle,and the lower the rated speed,the larger the helix angle.When designing the rear drum,the lower the rated speed,the smaller the blade helix angle,the higher the rated speed,the larger the helix angle.When choosing a scraper conveyor,the gap between the coal shovel plate and the unloading end of the drum should be minimized,and the appropriate height of the coal baffle should be selected according to the over-throwing situation of the front drum.