The Study Of Parameters And State Forecasting On Coal Spontaneous Combustion Based On Fractal And Chaos

The spontaneous combustion of coal is one of the major disasters influencing safe production of coal mine. It has very important theoretical significance and engineering applying value for effective prediction and forecasting on coal seam fire to explore the intrinsic rule in the coal spontaneous combustion. Therefore, some attemptable researches on coal spontaneous combustion has been done base on chaos and fractal theory. The fractal pore structures and hole ratio of coal has been analyzed, the flectional factor of fractal channel and some characteristic parameters have been computed.Base on the results. In addition, researching on the time series of coal autoxidation indicates that the time series can be qualitication described with fractal dimension(D) under no-scaled zone. And it obeys the fractal distributions. Although it is disorderly and unsystematic on the surface. Ddifferent fractal dimension reflects the different degree of the self-ignition. The value of fractal dimension in high temperature is higher than that in normal conditions. But the Hurst exponent(H) is just the reverse. D and H indicate that the system in high temperature is more complex than in normal . The chaos dynamical parameters in coal spontaneous combustion was discussed. The initial value susceptivity and the longest forecastble time, the least number of independent variable , the chaos degree and the average forecastable time of the system have been calculated. Finally, it has been proved that the time series of coal autoxidation is chaostic. And the time series have been forecasted by the method based on the maximal Lyapunov exponent.