| With the vigorous development of mine industry,the underground workers are seriously threatened by underground sudden shaft mine fire,meanwhile,the mine equipment and resources are destructed severely.Spontaneous combustion is the main form of mine fire.The major reason of the temperature increase is remaining coal reacts with the oxidation of air leakage,which has been important factor of the inverse determination of the location of the fire source in the mining area,and thus it can prevent spontaneous combustion in mining area effectively.The characteristic of fiber optic temperature measurement is that it has good adaptability in nasty environment and high resistance to interference,which determine its suitability for mining area environment.However,the information of temperature which collected by measurement fiber arranged in the middle of mining area and the lower down-slot is easily missing on account of the geological condition change and the influence of the falling rocks in the mining area,for this reason,it is impossible to precisely locate the internal fire source in mining area.It has certain application value that identify the fire source location and intensity in mining area by limited remaining temperature data in the location of the upper down-slot of the mining area.The mining area heat transfer mathematical model area simplified and constructed to analyze the complex flow environment of goaf according to the heat transfer characteristic of mining area.The analytical solution of the temperature in the extraction zone under the condition of single-point fire source is solved by the Green’s function method,and the temperature model of the internal field of the extraction zone is derived,and the effects of the intensity of the fire source,heat generation time,thermal conductivity and the different locations of the fire source on the temperature field of the extraction zone are also studied.The experimental research platform of temperature field evolution in goaf was set up,and the temperature distribution law of goaf model under different particle sizes and fire intensity was experimentally studied.Research shows that under the condition of windless insulation,the distribution of temperature field is round,and the higher the wind speed,the greater the influence of wind flow on the temperature field.The greater the intensity of the fire source,the greater the temperature field changes,and the farther away from the fire source,the smaller the temperature change rate.In the absence of measurement data,a method of determining the location of fire source in goaf based on Bayesian inference is put forward,which proves that the Metropolis-Hastings algorithm is feasible to express the objective function by sampling.The experimental platform is used to verify the method,and the results show that Bayesian inference method can get good results in the research of fire source location in goaf.Research on the location of fire source in goaf is of great significance,which will improve the key technical level of mine safety situation judgment,rescue and disposal in China,and provide strong scientific and technological support for comprehensively improving mine safety guarantee capability in China. |
