| In this thesis, the author discusses in more detail the character of Y-type ventilationsystem, and take a working face of Jixian coal mine of Shuangyashan bureau of mines inHeilongjiang province as the object of study, simulates the law of gas flow and thedistribution of gas concentration in full-mechanized mining working face of Y-typeventilation system. The author also calculates and simulates the―three zones‖height ofoverlying rock, and obtains the gas treatment mode of Y-type ventilation system in coalmining working face.At first, the author summarizes the several main ventilations, law and the theory aboutthe flow of gas from gob, the status of research and application of gas treatment technology,and the gas seepage law in gob of Y-type ventilation system. the author studies the theoryabout porous medium and seepage, establishes the mathematical model of gas migration ingob and its general form and numerical solution. Secondly, predict the emission of gas ofworking face, and programs User-Defined Function. The author simulates the situation ofair flow field in gob area and gas field of Y-type ventilation system by using FLUENT(CFD software). The law about the situation of air flow field in gob and gas field isconcluded by simulating, and the author obtains the gas flow and concentration distributionof Y-type ventilation system in gob. At the same time, the author calculates and simulatesthe―three zones‖height of overlying rock by UDEC numerical simulation software, andobtains the height of caving and fissure zone, which can provide a reliable theoretical basisfor gas control in gob. At last, the author investigates the influence of gas emission, and putforward the comprehensive gas treatment model of coal seam pre extraction+Y-typeventilation system+roof high drilling drainage in working face, which can drainages gas in the gob effectively, solves the problem of gas overrun in working face, guarantees the safetyof the mining face. |
PDF Full Text Request