低温条件下煤的热物性参数试验研究  

Identification and determination of the thermophysical properties of coal at lower temperature

作　　者：肖旸 陈龙刚[1,2] 李青蔚 张馨悦 白祖锦[1] 王凯 XIAO Yang;CHEN Long-gang;LI Qing-wei;ZHANG Xin-yue;BAI Zu-jin;WANG Kai(College of Safety and Engineering,Xi'an University of Sci- ence and Technology,Xi'an 710054,China;Shaanxi Key La- boratory of Prevention and Control of Coal Fire,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]西安科技大学安全科学与工程学院,西安710054 [2]西安科技大学陕西省煤火灾害防治重点实验室,西安710054

出　　处：《安全与环境学报》2018年第6期2190-2194,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51704226)

摘　　要：掌握钻孔冷冻取心与液态CO2压裂过程中,煤在低温环境中(-50~50℃)的热物性参数(热扩散系数、比热容和导热系数)及其量化表征,对煤层瓦斯抽采具有重要的实际意义。采用LFA457激光导热仪分别对5种不同变质程度的煤进行热物理性质的测试,从-50℃开始,以10℃为温度梯度记录数据,得到低温环境中煤热物性参数的变化规律,将低温环境分为负温-50~0℃与正温0~50℃两个阶段,对比分析影响煤热物理性质的因素;并使用灰色关联度分析方法对煤的热扩散系数、比热容、导热系数与煤的固定碳、挥发分、灰分、水分进行关联度分析。结果表明,在低温环境中,煤的热扩散系数随温度升高而降低,比热容与导热系数随温度升高而升高。煤热物性参数的平均变化率在负温阶段比正温阶段大,是因为煤的晶格振动与分子运动在负温升温阶段变化更为剧烈。通过对比水分、挥发分、灰分、固定碳与导热性质的关系,发现煤中的固定碳含量对煤热物理性质的影响最大,其次为挥发分与灰分,煤中水分是对热物理性质影响最小的因素。The given paper is to devote itself to providing ways for doing comparative analysis methods of the factors that may affect the changes of the coal thermal properties.As is known,the thermophysical parameters(thermal diffusivity,specific heat capacity and thermal conductivity) of coal in the low temperature environment(-50-50 ℃) during drilling and frozen coring and liquid CO2 fracturing.Since the gas thermophysical properties have a very important practical significance for the coalgas drainage in the coal seam,it is of great meaning to get to know the variation of coal thermal parameters at low temperature,which can be divided into 5 different degrees of coal,data can be recorded at a temperature gradient of 10 ℃ from-50 ℃,whereas the lower temperature in the coal seam can be divided into two stages,that is the negative temperature-50-0 ℃ and the positive temperature 0-50 ℃,through comparative analysis of the factors that affect the changes in coal thermal properties.Such properties can be tested by using a Laser-flash apparatus LFA457 by grasping the thermophysical parameters(thermal diffusivity,specific heat capacity and thermal conductivity) of coal in the low temperature environment(-50-50 ℃) in the drilling and frozen coring and liquid CO2 fracturing.So far as we can do,the thermophysical properties of 5 different degrees of coal,can be tested via a Laserflash apparatus known as LFA457 so as to keep the recordings of the data recorded at a temperature gradient of 10 ℃ from-50℃,and gain the variation of the coal thermal parameters at low temperatures,which can be divided into two stages,that is,the negative temperature degrees between-50-0 ℃ and the positive temperature 0-50 ℃.Through a comparative analysis of the factors that affect the changes in the coal thermal properties,it would be possible to calculate and analyze the thermal diffusivity,the specific heat capacity,the thermal conductivity and the fixed carbon,volatile,ash and the moisture of the coal under study with the gray rela

关 键 词：安全工程 导热系数 热扩散系数 比热容 灰色关联度 

分 类 号：X936[环境科学与工程—安全科学]