Numerical Study Of More Tuyere And Pressure Pump Combination Mixed Ventilation On Mechanized Heading Face

With China’s rapid economic development, energy demand is expanding. As coalis the main energy in our country, how to develop our country’s coal, minimize theeconomic costs and reduce the mine accident has become a problem of concern.Mechanized heading face is the main dust source areas, its ventilation environment isparticularly important to the health of workers. The traditional ways of ventilation ina certain extent can reduce pollutant concentration of mechanized heading face, butthe pollutant concentration remains high, especially the dust concentration is stilloverweight. Countless people died each year because of pneumoconiosis and coal dustexplosion accidents, this seriously hindered the economic development of coalindustry. Therefore, in order to reducing gas and dusting concentration and improvingworking environment, putting forward a new type of ventilation method is of greatsignificance.In this paper, it finds many dust sources on mechanized heading face, and themain producing dust points are heading end and transfer point by site investigationand testing to C103mechanized heading face of Nahe coal mine in Guangxi. On thebasis of previous studies, this paper analyzes dust characteristics and migration law ofmechanized heading face. The ventilation physical model and mathematical model isestablished, according to characteristics of the producing dust and air distributionfeatures of long-pressure and short axis ventilation. It obtains dust concentrationdistribution and air distribution of the three dimensional flow field aboutlong-pressure and short axis ventilation by using FLUENT software to numericalsimulation. At last, the correctness and feasibility of the simulation calculation isverified by comparing calculated results with the field measurement data.Aimed at the shortage of long-pressure and short axis ventilation, this paperproposes a new way of ventilation-more tuyere and pressure pump combination mixedventilation combined with the actual situation. This way of ventilation sets a draughtnear the transfer point to control dust ejected from the transfer point area, and realizessecondary dust control to the dust of working face. By setting a bifurcation draught onpressure ram behind the transfer point, it can not only solve the problem of smallervelocity in overlapping period between pressure and suction ram, and can also reduceair volume and wind speed of the pre-pressure ram, which can prevents air volumeand velocity of the pre-pressure ram becoming too large that causes dust float and is difficult to collect all dust air-flow. Based on the three dimensional flow fieldnumerical simulation of more tuyere and pressure pump combination mixedventilation, it gets characteristics of air distribution and law of dust concentrationdistribution. Through the analysis of the air distribution, when pre-pressure tuyere is8m to9m to heading end, the blow-suction rate is0.8~1.2, postposition pressuretuyere is10m to11m to the heading driver, exhaust inlet is1m to the transfer point,dust control effect is best, it provides reference for engineering application.