| At present coal is the national economy energy foundation but caused considerable damage for the environment. The deep processing and clean mining can effectively improve its influence to environment. In clean coal mining technology areas, underground in-situ pyrolysis and gasification of coal mining is an important direction for clean coal technology mining. The research of this aspect needs to solve the transmission process of pyrolysis products and regional design and control of pyrolysis. This needs the permeability of coal pyrogenation process characteristics and deformation characteristics have deeper degree cognition. This thesis mainly to coal pyrolysis and deformation theory as a foundation, through a lot of experiments and the data analysis, the study takes the lignite in Inner Mongol for example. Through theoretical analysis and experimental study, we conducted systematic research on the deformation character of lignite in the pyrolysis process,and also when it was applied to industry. The results will help people learn more deformation characteristics in high temperature pyrolysis process of lignite. It will have certain directive role for the future research on coal underground in-situ pyrolysis mining and so on. Using coal rock triaxial stress permeation experiment equipment studied the deformation characteristics of lignite samples at low temperature. That is we experimentally studies the deformation characteristics of lignite in different temperatures and different underground in-situ simulated stress state, and obtain the period lignite stress-strain curve and creep rule at low temperature finally and get conclusion:the downward trend of elastic modulus of coal with the rise of temperature, explains that coal become soft. Within 100℃, as with the rise of the temperature, the creep cycle of coal appeared shorten variable, and the maximum creep is in decreased. The fitting result showed that the fitting rule of specimen creep generally grow by exponential function within the 100℃Using high temperature pyrolysis penetration-deformation test platform studied the deformation characteristics of lignite under high temperature period (100℃-600℃). The stress-strain curve and creep regularity was obtained in different conditions of the stress under high temperature:As the temperature increases, the overall variation trend of elastic modulus of coal sample rise gradually, arrived at the maximum value within 200℃-250℃, and gradually reduce above 250℃.The fitting results of creep show that the creep rule of lignite is more complex under the composite function of high temperature pyrolysis and triaxial stress.overall the creep rale increase or attenuate by exponentially function. As the pyrolysis of coal occurs, the intensity of coal samples decreased, the creep enhancement, that is that as the time continue,the deformation is bigger. And by using servo control uniaxial compressive tester measured the elasticity modulus and poisson's ratio of lignite after under high temperature pyrolysis. The change rule of elastic modulus with the temperature of lignite under the conditions of uniaxial compression was obtained:After the high temperature pyrolysis and under the uniaxial compression, the elastic modulus attenuate by logarithmic law with the change of the temperature. The elastic modulus of coal samples under uniaxial compression is 20-300 times small than the elastic modulus under high temperature and triaxial stress after high temperature pyrolysis.Put forward some research direction, contents and key of follow-up work for some key problems of industrial implement of the coal underground in-situ pyrolysis, such as products transmission in the process of pyrolysis, thermal deformation characteristics of coal and surrounding rock in the process of pyrolysis and prolysis regional control etc. The purpose is to provide the basic theory for the industrial implementation of coal underground in-situ pyrolysis in future.
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