While the gas drainage efficiency has attracted much attention,the importance of safe drainage should be recognized.Under the effect of gas drainage,air flows into the drainage borehole through fractures,providing sufficient oxygen for coal spontaneous combustion and making gas drainage concentration decline into the explosion scope.Based on the risk of coal spontaneous combustion induced by gas drainage and gas explosion in the drainage pipe,the concept of safe drainage was proposed,and the safety factor was defined to quantitatively evaluate the security of gas drainage.By establishing the seepage and diffusion of multicomponent gas,coal-oxygen reaction and heat transfer equations and analyzing the evolution of multicomponent gas flow,oxygen concentration and temperature field,the theoretical model for safe drainage of coal seam gas was built.Taking gas drainage project in Shanjiaoshu Mine of Panjiang Coal and Electricity Group as example,the influence of negative pressure,sealing quality,permeability of distressed zone,gas absorption speciality and coal spontaneous combustion characteristics on safety factor of gas drainage were studied,and some technical measures to ensure the safe drainage were given.
coal seam gasgas drainagesafety factor of gas drainageevolution of gas flow field
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维普
