Research On The System Of The Heavy Railway Tunnel Fallen Coal Dust Collection

Railway tunnel fallen coal is considered to be an unresolved stubborn problem on heavy loading railway line for many years.Taking Datong-Qinhuangdao Railway line as an example,it need to open an extra special coal train over ten thousand tons level every ten minutes.In addition,because of so many tunnel entrance,the coal on the train will be rolled up under the disturbance of the air flow and falls to the ballast bed when the train passes through the tunnel.For long time accumulation,the fallen coal impact the railway maintenance work along the line seriously,and even bury the railroad rails when heavy accumulated.The traditional methods to prevent the coal fallen are not particularly good,such as installing the iron cover at the top of the train,covering tarpaulin and dust suppression method by sprinkling chemical reagent on the surface of coal.For railway tunnel fallen coal having the problems of small particles,light quality,human manually from the low efficiency and high cost,a new railway tunnel fallen coal dust collection device was designed.Research group investigated Datong-Qinhuangdao Railway line.And we put forward the design plan of a fixed model of tunnel fallen coal dust collecting equipment for heavy loading railway,combining with the domestic and overseas research results and direction of dust remove equipment.The mathematical model of heavy loading railway tunnel fallen coal dust collecting equipment was established.After analyzing the different turbulence models in CFD,using RNG k-e model in the viscous vortex model to simulate the three-dimensional strongly swirling turbulent,a better simulation result was got,which was calculated by the non-direct numerical simulation method due to the unidirectional flow.Pneumatic conveying system of coal and air in the pipeline transportation was calculated by Navier-Stokes equation,using the particle trajectory model which was based on Euler Lagrange coordinate system,regarding the solid particles as discrete phase and regarding the gas as the continuous phase.The three-dimensional modeling of heavy loading railway tunnel fallen coal dust collection equipment was established.Simulation analysis and field experiment demonstration of blanking device,conveying device and sucking device were carried out.(1)When the numerical simulation of the cyclone separator in blanking device was done,the coal particles with the minimum diameter greater than 0.005 mm can be better realized the gas-solid separation in the XF-1 cyclone separator.(2)During the study for the conveying device,the effect of the multiple branch pipe spacing and the angle of incidence of the coal particles on the main coal conveying pipe flow field was studied,which was based on Fluent finite element simulation software,it was more conducive to the railway tunnel fallen coal transportation when the branch pipe spacing in the vicinity of 750 mm and coal particles’ incident angle less than 45 °.(3)The old suction nozzle was improved by new suction device.The total pressure distribution,the gas velocity,particle trajectory,particle velocity and other content in the simulation results of the old and new suction devices were compared and analyzed.The results provide a theoretical basis for the latter field test.Field comparative test was carried out,which was between the different power size of the equipment of the heavy loading railway tunnel fallen coal dust collection.The result of their coal conveying efficiency was concluded,which were contrasted through analysis with the results of simulation.The final comparison results will provide the basis for future improvement.