Causes And Control Of Disaster By The Heat From Polyurethane Materials Used In Mine

To solve the heat from polyurethane used in mine could lead to mine fire,combined with on-site fire-fighting technology,the mechanism of the mine fire polyurethane materials is researched,as well as,the heat yield of mine polyurethane material is quantitative calculated,and the internal heat distribution in the mine filling polyurethane material is numerical simulated,what's more,the feasible fire prevention and control plan is put forward according to the results,by the theoretical analysis,experimental research,numerical simulation and other research methods.By the research of a kind of mine polyurethane material under the specific physical field conditions,a calculation method can be obtained to determine the maximum safe dosage of various mine polyurethane materials in different mine environments.The following research results were obtained:1)The mine fire is triggered by the use of mine polyurethane for main two reasons:internal heat in polyurethane accumulation causes the material thermal decomposition,so uneven inside and outside stress of polyurethane produce cracks through the polyurethane material,resulting in that oxygen into the polyurethane filling body contacts with hot polyurethane material causing a fire;coal is affected by the exothermic effect of polyurethane material,the sum of heat absorption and heat production from natural oxidation is greater than heat loss,jumping from slow oxidation stage to accelerated oxidation stage,thus accelerating the process of spontaneous combustion.2)The energy produced by polyurethane is calculated according to chemical reaction enthalpy change.Maximum reaction temperature of 140?,for example,the theoretical value of the heat from polyurethane to itself and coal is calculated.3)By comparing the 1m~3 experimental results and numerical simulation results of a kind of polyurethane used for coal mine filling,it is determined that the numerical simulation can accurately reflect the thermal distribution law and maximum temperature inside the material when heat accumulates.By using the heat transfer model of solid material per unit volume,the regional maximum temperature and its occurrence time under the condition of each filling quality were fitted and analyzed,as well as the function of the maximum temperature and its occurrence time with filling quality were obtained by fitting analysis.4)The thermal decomposition temperature and ignition temperature of the mine polyurethane material used in this study were obtained by thermogravimetric analysis experiment,regarding its smaller value as the maximum safety temperature.The theoretical maximum safe usage of this kind of polyurethane material under the physical condition set in this paper is 11.72t,calculated by the function of numerical simulation,and the feasible prevention and control measures of mine fire caused by the exotherm of the mine polyurethane are put forward from the aspects of hindrance,fire monitoring and prediction.5)Combined with accident cases,the application method of the this paper research conclusions obtained is analyzed in the field.