| Coalfield fire is one of the major natural disasters in the world, which can cause a direct economic loss up to tens of billions of dollars each year. What’s more, large quantities of gas, such as C02、SO2, produced by fire areas formed by coalfield fire, has great impact on ecological environment. With the progress and development of the society, the research on coalfield fire and how to deal with it initiates. The majority of coalfield fires are caused by spontaneous mine fire, accompanied by mine goaf roof collapse or closed wellhead leakage lax which lead to oxidation of floating coal that is easy for spontaneous combustion in low temperature. Then spontaneous combustion occurs under the condition of heat accumulation environment, resulting in greater collapse which makes the air leakage more and more serious and more and more intense combustion, and eventually a coal fire area is formed.Taking Yonghong fire area of Zhungeer coalfield as a template, combined with the theory of coalfield fire formation, aiming at the combustion characteristics of Yonghong fire area, the present study proposed comprehensive fire prevention and control technology in Yonghong fire area and confirmed how scientific and accurate it is through monitoring fire area and fire area management method for measuring radon inversion.The present study contains six parts as follows:First, the research on former Yonghong small kiln mining environment consisted of the geological characteristics of Yonghong small kiln coal seam and roof and the investigation of the roof collapse and surface cracks formation. Therefore fire space model is established.Second, through the research on respective breathable regularity of Yonghong small kiln goaf caving zones, the calculating formula of ventilation rate was deduced. And based on stack effect principle, the outside air and gas in air by collapse fracture flow was analyzed and the cause of goaf coal spontaneous combustion of float coal continuous oxygen supply was initially identified.Third, after goaf float coal spontaneous combustion of Yonghong small kiln, the release of heat produced temperature difference between inside and outside changes which caused the fire pressure, at this time, which offered the ventilation and oxygen supply power. Based on these analysis and research above, fire leakage system was established.Fourth, during the process of governance and management in Yonghong fire area, in order to confirm the air leakage passage, new engineering methods were proposed:direct injection method and infrared imaging method. Fifth, based on the macro analysis of combustion thermodynamic in Yonghong fire area, combined with the actual construction situation of Yonghong fire area, we proposed a surface heat source rock excavation of Yonghong fire areas to reduce the fire area internal accumulation of heat, so that not only fire air pressure was reduced to suppress fire burning, but it facilitated the construction machinery.Sixth, based on the theoretical analysis of Yonghong fire area, comprehensive fire control technology was proposed. In addition, Yonghong comprehensive fire control technology based on fire are analysis theory verified by monitoring and measurement method of radon inversion achieved great effect on Yonghong fire area management. |
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