Study On Gas Desorption Laws Of Coal Particle At High Temperature

Based on theoretical analysis,the experiment simulation and regression analysis method are adopted in this paper to study on gas desorption laws of coal particle under the condition of different temperatures and pressures,especially the high temperature.The sensitivity to coal of temperature and pressure are compared.It provides guidance for air volume management and gas content determination to ensure the safety of mine production.This paper uses gas adsorption and desorption instrument to simulate systematically the gas desorption process about fresh coal of 5301 working face in Tang Kou coal mine under the experimental conditions of adsorption temperature:45 ?,25 ? and 35 ?,desorption temperature:45 ?,25 ? and 35?,adsorption balance pressure:0.3MPa,0.5MPa and 0.8MPa.According to the experiment data,the changing curves of gas desorption quantity and desorption gas velocity along with desorption time are drew under the different desorption temperatures,different adsorption temperatures and different adsorption balance pressures.Sum up and get the following three rules:rising desorption temperature promote the gas desorption,i.e.,desorption quantity increase and desorption speed fast;adsorption temperature is opposite,as adsorption temperature rise,the gas desorption quantity decrease;adsorption balance pressure is the same as desorption temperature.Using software to process the experiment data in methods of regression analysis and fitting,obtain the relationship between gas desorption quantity Q and desorption temperature T:QT =aebT.Based on it,the influence coefficient r that desorption temperatures affects gas desorption quantity is obtained and the calculation formula of gas desorption quantity under the influence of desorption temperature is established:QT(t)=Q15(t)e0.022(T-45).The function relationship between gas desorption quantity Q and adsorption balance pressure P is Qp=APB and the relationship between gas desorption speed V and desorption time t in case of different adsorption balance pressures is V=?Pkp·t-k1.Analysis data and studying on the impacts to the changing quantity and changing rate of gas desorption in the following cases:adsorption temperature changes,desorption temperature changes,adsorption temperature and desorption temperature changes simultaneously and adsorption balance pressures changes.The results show that the gas desorption quantity reduces about 20%if desorption temperature reduces by 10 ?,and it is hardly influenced by the initial desorption temperature and initial adsorption balance pressure.But when adsorption temperature rises or adsorption balance pressure decreases,the changing rate of gas desorption increases with the rising of initial adsorption temperature or initial adsorption balance pressure.Then the changing quantities and changing rates of gas desorption in case of different datum(unit volume,unit rate,geothermal gradient,gas pressure gradient,etc.)are compared.The sensitivity of pressure to coal is superior to temperature,and adsorption temperature is superior to desorption temperature.