DESORPTION CHARACTERISTICS OF ADSORBED GAS IN COAL SAMPLES UNDER COUPLING TEMPERATURE AND UNIAXIAL COMPRESSION
HE Manchao1，2，WANG Chunguang1，2，LI Dejian1，2，LIU Jing1，2，ZHANG Xiaohu2
(1. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Beijing 100083，China；2. School of Mechanics and Civil Engineering，China University of Mining and Technology， Beijing 100083，China)
Abstract：The desorption process of adsorbed gas in coal from Nanshan coal mine is studied using an experimental system with temperature-pressure coupling in particular to treat the multiphysical effect on deep coal sample. This experimental system has been designed to apply triaxial pressure and temperature to coal sample，and reproduce the desorption-releasing process of absorbed gas as a result of combination of pressure and temperature. Uniaxial compression tests are carried out on coal samples under constant temperature and increasing temperature，respectively. After failure，the deformed samples were subjected to confining pressures. In test，the releasing gas pressure and flow are real-time monitored. The mixed gases is sampled and detected by using a gas chromatography. The results show that a spontaneous negative value observed in gas pressure is consistent with the refluence of gas determined from the volumetric dilatancy development. A large amount of gas is expelled during the closure of fracture due to the present of the confining pressure. Correspondingly，the concentrations of methane，carbon dioxide and ethane are increased sharply. Temperature change is one of desorption-induced factors for adsorbed gas. The existence of a large number of connected cracks in coal matrix may play an important role in gas transport. The mechanism of gas emission is also preliminarily discussed.
何满潮,王春光,李德建,刘静,张晓虎. 单轴应力–温度作用下煤中吸附瓦斯解吸特征[J]. 岩石力学与工程学报, 2010, 29(05): 865-872.
HE Manchao1，2，WANG Chunguang1，2，LI Dejian1，2，LIU Jing1，2，ZHANG Xiaohu2. DESORPTION CHARACTERISTICS OF ADSORBED GAS IN COAL SAMPLES UNDER COUPLING TEMPERATURE AND UNIAXIAL COMPRESSION. , 2010, 29(05): 865-872.
