Research Of Adsorption Model Under High Temperature And Pressure Coupling On Deep Coal Seam

In recent years, the depth of China’s coal mining continues to increase, but when the burial depth reaches a certain value, gas content will not increase or even slightly lower, the relationship between gas content and depth is no longer a simple linear relationship, which different from conventional conclusions. And with increasing depth, 8m3 / t that the original critical gas content value is no longer suitable for the prediction of mine outburst.In this paper, Pingdingshan number one coal mine as an example, we predicted the temperature and pressure of the deep coal seams, on this basis, made the adsorption isotherm experiments under the high temperature and pressure, made a comprehensive analysis of the effects of temperature and pressure on the adsorption characteristics, the pressure increases, gas adsorption volume increases, the temperature rises, the amount of adsorbed gas reduced, the characteristics of adsorption under high pressure and temperature, is the result of the combined effects of pressure and temperature,based on the experimental data,we obtained the linear regression equation of adsorption constant with temperature, and established the calculation model ofgas adsorption content.Based on comprehensive analysis of the impact on porosity of the changesin temperature and pressure,we made a porosity calculation model,established a computational model of free gas content, thus obtained the comprehensive gas adsorption model under the coupled action of high temperature and high pressure. Using this model, the theoretical value of gas content on the depth of 850 m was calculated and compared to the measured values, and on this basis, we proposed a new gas content outburst critical index.