Regular pattern effect of negative pressure on spontaneous combustion in gob

摘要

To Kailuan Group Lv Jiatuo mine 5877Y working face gob as the research background, and using the method of numerical simulation and field experiment, the effect of different drainage pressure on spontaneous combustion "three zones" under the condition of the buried pipe in the gob was studied. Results show that after the negative pressure is added, the spontaneous combustion zone width of the gob is smaller and then increases. Based on the analysis of the data obtained from field beam tube, the simulation results agree well with the simulation results, which proves the validity of the simulation of spontaneous combustion in gob, and provides a reasonable reference for the gas drainage in the similar condition. Fire and gas are the two major disasters that restrict the safety and efficient development of coal mine, spontaneous combustion in gob is the current coal enterprises especially the great disaster of coal seam spontaneous combustion tendency exists. At present, many mines adopt gas drainage method with high suction roadway to control gas overrun, this method also has great influence on the air leakage field in gob, increase the probability of spontaneous combustion of residual coal. Therefore, it is of important and practical significance to prevent spontaneous combustion of abandoned coal in gob and avoid fire accidents under pumping condition. Based on the study of the mechanism of spontaneous combustion of coal, the theory of gas drainage and the theory of three zones of spontaneous combustion, the application and research status at home and abroad are summarized. To Kailuan Group Lv Jiatuo mine 5877Y working face gob as the research background, and using the method of numerical simulation and field experiment, the effect of different drainage pressure on spontaneous combustion ''three zones " under the condition of the buried pipe in the gob was studied. Results show that the distribution of oxygen concentration field under the condition of no buried gas drainage was simulated by establishing the mathematical model of spontaneous combustion in gob and using COMSOL numerical simulation software. The rationality of the model is confirmed by comparing the experimental data and the simulation analysis of the beam tube monitoring, Then, under the condition that other conditions and parameters remain unchanged, the negative pressure of buried pipes with lOkPa, 20kPa and 30kPa sizes is set. The range and influence law of ''three zones" of spontaneous combustion in gob under different pumping negative pressure are obtained; When the negative pressure is added to the gob, the width of the spontaneous combustion zone in the gob becomes smaller and then increases. The data obtained from the monitoring of the beam tube on the spot coincide with the results of the simulation. The validity of the spontaneous combustion simulation in the gob is well verified, The research results provide theoretical support and basis for mastering the heating law of spontaneous combustion of abandoned coal in the gob and preventing and controlling the spontaneous combustion of coal seam.