Influence of heterogeneous pore-fracture environment on the evolution of underground coal fire propagation based on multi-physical field coupling
coalfield fire, pore-fracture environment, heat transfer, chemical reaction, multi-physical field coupling
Resource Development and Utilization > 8. Mine Engineering Geological Environment and Disasters
Abstract Accepted
芸卓 李 / 中国地质大学（北京）
贺涛 苏 / 中国地质大学（北京）
The development of pores and fracture in coalfield fire area can promote the abnormal temperature, the greenhouse effect, and the release of toxic gases. It is of great significance to study the dynamic distribution characteristics of temperature field and concentration field of typical gas products in coalfield fire area under different pore-fracture environment for revealing the spreading law of underground coalfield fire. In this paper, the combined effect of coal combustion chemical reaction, heat energy transmission, flue gas seepage and pore-fracture development are considered. The evolution characteristics of the oxygen consumption, heat release rate and thermodynamic parameters of coal samples in coalfield fire area were obtained by thermogravimetric analysis. Taking Daquanhu coalfield fire area as an example, a three-dimensional unsteady model of coalfield fire area coupled with multiple physical fields was constructed based on the chemical reaction of coal combustion, convection heat transfer in fractures, heat transfer in porous media, gas seepage and improved partial differential equation of pore-fracture evolution. The evolution law of temperature field, CO2 and CO concentration field in the coal field fire area under different air leakage and geological fracture conditions is analysed, and the influence mechanism of pore-fractures on coal fire spread and development is obtained.