Research On Numerical Simulation Of Respirable Dust Distribution Rule In Fully-mechanized Mining Face

Among all kinds of the dust produced from many steps of the productive process of coal mine, respiratory dust, especially PM2.5, is the most harmful part to human body, causing serious damage to the underground workers' safety and health. The respirable dust content of airflow of fully-mechanized mining face, which is one of the main producing dust area, is generally much higher than the recommended minimum value of the Coal Mine Safety Regulation, under the condition of no other measurement for dust reduction when the internal and external water spray of the shearer is in working order. Therefore, it's significant to master the respirable dust distribution rule to make an efficient scheme about dust reduction.Taking the No.14618 fully-mechanized mining face as the research object, which was in Zhujiahe coal mine of Pubai mining bureau. The models of geometry and mesh have been established. On the basis of gas solid two phase flow theory, the DPM model of respirable dust distribution in fully-mechanized mining face, which was under the frame of Euler-Lagrange model, has been established. The model about the distribution of respirable dust in fully-mechanized mining face has been simulated by Fluent, with using the Realizable k-? model of RANS as the method of simulating the turbulent flow field, and applying SIMPLEC as the numerical solution for gas solid two phase flow. Then the result of simulation has been contrasted with measured data.The simulation results show that each concentration of respirable dust at the pavement breathing zone is gradually rising from the positions of the shearer body and advancing support to downwind area, for its character of hardly sedimentating and easy to diffuse with airflow, whatever the direction of the airflow during cutting process. So it has been suggested that the areas of shearer body centered within 10 m up and down wind as well as moving advancing supports nearby should be treated as major zones to reduce dust concentration.Considering a number of factors, finally a reasonable optimal wind speed, which has the minimum influence to the pavement respiratory zone, has been proposed after comparing the distribution of the concentration of respirable dust under several differential wind speed.