【作者】 韩德虎；

【导师】 胡耀青；

【作者基本信息】 太原理工大学 ， 安全技术及工程， 2011， 硕士

【摘要】 煤是目前国民经济的能源基础,但对环境也造成了相当大的破坏,对其进行深加工以及洁净开采可以有效的改善其对环境的影响。在洁净煤开采技术领域中,对煤进行地下原位热解开采和气化开采是洁净煤技术的一个重要方向,这方面的研究需要解决热解过程中产物的传输以及热解区域设计与控制的问题,这就需要对煤热解过程中的渗透特性与变形特性有更深程度的认识。本论文主要以煤的热解及其变形理论为基础,通过大量实验以及采集的数据分析,对内蒙古某褐煤热解过程中反映出来的变形特性及其在将来工业应用中存在的问题做了较为详细的分析,所得结果有助于人们更多的了解褐煤在高温热解过程中的变形特性,对今后研究煤的地下原位热解开采等具有一定的指导作用和意义。论文采用煤岩三轴应力渗透实验设备研究了所取褐煤试样在低温段内的变形特性,即在不同的温度下以及不同的地下原位模拟应力状态下对褐煤的变形特性进行了实验研究,最终得出褐煤在低温段内的应力-应变关系曲线及蠕变规律,得到结论：煤体的弹性模量随着温度的升高呈现下降的趋势,说明煤体在变软；在100℃以内,煤体的蠕变周期随着温度的升高出出现了缩短,最大蠕变应变量也在减小；拟合结果显示在100℃以内,试件的蠕变拟合规律总体呈指数型函数增长。通过利用高温热解渗透-变形试验台对褐煤在高温段(100℃-600℃),的变形特性进行了研究,得到了褐煤在高温段内不同的应力状态条件的应力-应变关系曲线及蠕变规律,得出结论：随着温度的升高,煤样的整体弹性模量变化趋势为先逐步上升,在200℃-250℃时达到最大,250℃之后,其弹性模量又逐渐降低；褐煤在高温热解和三轴应力的复合作用下,从蠕变拟合的结果看表现出来的蠕变规律比较复杂,总体上其蠕变规律呈指数型函数增长或衰减；随着煤的热解发生,煤样的强度降低,蠕变增强,即随着时间延续,变形更大。同时利用伺服控制单轴压缩试验机对褐煤在高温热解后单轴压缩下的弹性模量与泊松比进行了测试,得到了单轴压缩条件下褐煤的弹性模量随温度的变化规律：褐煤热解后单轴压缩条件下,弹性模量随温度的变化基本呈对数规律衰减,高温热解后煤样的单轴压缩弹性模量比高温三轴应力下的弹性模量小20-300倍。对煤体地下原位热解的工业实施中存在的一些重点问题,如：热解过程中产物的传输、煤体及围岩热解过程中的热变形特性以及对于热解区域范围的设计控制等,提出来一些见解与认识,从而为今后煤炭地下原位热解技术的进一步发展提供一些参考。更多还原

【Abstract】 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.更多还原