Prediction And Research Of The Hidden Spontaneous Points In Coalbed Based On Chaos Theory

Coal’s spontaneous combustion troubles are one of the greatest threats to the coal’s safeproduction. Spontaneous combustion is an objective phenomenon in the nature, but isinvisible. If this phenomenon is not prevented, losses of economy, property and safety will beimmeasurable. By statistics, conflagrations resulted from spontaneous combustion take up of90percent of the total. So, how to precaution against spontaneous combustion in advance isthe most important task for researchers and scholars in the different countries.In order to be capable of early detecting the spontaneous combustion source and takeeffective measures in time, this thesis applies chaos theory which is widely used in weaksignal detection to detect spontaneous combustion in theory. The main research content and resultsare as follows:1) In view of problem that traditional method’s defect in spontaneous combustion,considering gas nature produced in the progress of spontaneous combustion of coal, bycomparing the properties of the CO gas with the properties of the Non-hydrocarbon gasesproduced in the process of the coal’s spontaneous combustion, this thesis analyzes and selectsCO gas as the index gas predicting spontaneous combustion.2) The time series of CO is reconstructed and the biggest Lyapunov index method is usedto prove the chaos characteristics of CO gas.3) The simulation model of Duffing chaos oscillator is established and the principle ofDuffing oscillator testing CO is described. These can realize the prediction to Coal’sspontaneous combustion troubles.4) Duffing simulation system is designed. Ones the system’s parameters change, thesystem’s state can be changed immediately. By this system, parameters playing what king ofroles can be presented easily.