Numerical simulation of reasonable oxygen content in flue gas for preventing residual coal spontaneous combustion

doi:10.16265/j.cnki.issn1003-3033.2017.03.008

Abstract

Abstract: In order to determine the reasonable oxygen content in flue gas for preventing spontaneous combustion of residual coal in gob, a 3D numerical model, based on Computational Fluid Dynamics (CFD) and theory of coal-oxygen reaction, was built to simulate the residual coal's spontaneous combustion in top coal caving gob area in panel 8105 of Tashan Coal Mine. The migration of flue gas in gob, distribution of “three zones” of spontaneous combustion and temperature field with 3%-9% of O₂ content in flue gas were analyzed by numerical simulation. The results show that the injected flue gas can inert spontaneous combustion of the residual coal effectively. Along with decrease of oxygen content in the flue gas injected, the maximum width of the oxidation zone will decrease accordingly which is agreed with the curve of Boltzmann function and the maximum temperature of the residual coal will decrease exponentially. Lowering oxygen content in flue gas will improve the inerting effect of the residual coal. Based on the field measured data of the width of oxidation zone after nitrogen was injected, oxygen content is determined to be 7.08% as the reasonable upper limit in the flue gas for preventing spontaneous combustion of residual coal in gob.

Key words: gob, residual coal's spontaneous combustion, flue gas, reasonable oxygen content, numerical simulation

CLC Number:

X936

HUANG Ge, WANG Jiren, DENG Cunbao, HAO Chaoyu, WANG Xinyang. Numerical simulation of reasonable oxygen content in flue gas for preventing residual coal spontaneous combustion[J]. China Safety Science Journal, 2017, 27(3): 42-47.

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