不同预氧化温度下煤样热物性参数的实验研究

1.西安科技大学,安全科学与工程学院,陕西 西安 710054; 2.西安科技大学,陕西省煤火灾害防治重点实验室,陕西 西安 710054

热物性参数; 程序升温; 预氧化处理; 温度; 敏感性

Experimental study on coal thermo-physical parameters under the different peroxidation temperature
XIAO Yang1,2,YIN Lan1,2,MA Li1,2,ZHOU Yi-feng1,2

(1.College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi'an University of Science and Technology,Xi'an 710054,China)

thermo-physical parameters; programmed-temperature; pre-oxidation treatment; temperature; sensitivity

DOI: 10.13800/j.cnki.xakjdxxb.2018.0306文章编号: 1672-9315(2018)03-0383-06

备注

为了研究在不同预氧化温度下煤样热物性参数的变化规律,选取长焰煤进行热物性实验。首先通过程序升温氧化法对煤样进行预氧化处理,分别氧化升温至80,110,140,170,200 ℃.然后使用激光导热仪LFA 457装置测定在30~300 ℃温度范围内的煤样热物性参数,研究预氧化处理后煤样的热物性参数随温度的变化趋势,并分析预氧化处理后的煤样对温度的敏感性。结果 表明:在30~300 ℃范围内,随着温度的升高,煤样的热扩散系数呈现出逐渐降低的趋势,而煤样的导热系数和比热容呈现出逐渐升高的趋势,并且温度越高,煤样的热扩散系数的降低趋势以及比热容和导热系数的增大趋势越来越平稳。在相同温度下,预氧化处理煤样的热物性参数均高于原煤样。从敏感性分析可知,比热容对温度最敏感,而导热系数的敏感性最低,且当温度超过120 ℃时,煤样的预氧化温度越高,其热物性参数对温度的敏感性越低。实验结果对于了解煤层自燃和火灾蔓延过程中的传热具有指导意义,为煤自燃的防治提供理论依据和技术指导。

To investigate the variation law of the thermo-physical parameters of coal samples under the different pre-oxidation temperature,temperature-programmed apparatus was selected to treat the long flame coal,the coal samples were pre-oxidized at 80,110,140,170 and 200 ℃,respectively.Then,laser flash apparatus LFA 457 was used to measure the thermo-physical parameters of coal samples in the range of 30 to 300 ℃,which investigated the variation tendency of thermo-physical parameters of coal samples with temperature after pre-oxidation treatment,and analyzed the sensitivity of it to temperature.The results indicate that in the range of 30 to 300 ℃,with the elevating temperature,the thermal diffusivity of coal samples presented a decreased tendency,the thermal conductivity and the specific heat capacity presented an increasing tendency.Temperature was higher,the decreasing tendency of thermal diffusivity and the increasing tendency of specific heat capacity and thermal conductivity would tend to be weaker.At the same temperature,the thermo-physical parameters of pre-oxidation coal samples were higher than raw coal.It is found from sensitivity analysis that the specific heat capacity was most sensitive to temperature,whereas the sensitivity of the thermal conductivity was lowest.When the temperature was over 120 ℃,the higher the pro-oxidation temperature,the lower the sensitivity of thermo-physical parameters to temperature.Those results are meaningful for understanding of heat transfer in coal seam during spontaneous combustion of coal and fire spread,and provide a theoretical basis and technical guidance for the prevention of coal spontaneous combustion.