烟煤填料床低温氧化演变特性及影响因素研究
|
摘要
为了探究粒度及氧浓度对烟煤升温氧化的影响,搭建了中尺度煤炭填料床低温氧化试验系统。利用该系统在2 L/min的进气孔流速,从室温升温至230℃,对5组不同粒径分级煤样及在不同氧浓度下进行升温氧化实验。基于低温氧化曲线,以加速度突变点为基准,获取加速点温度、自燃临界时间和临界升温速率3个过程参量,藉以将其划分为缓慢升温阶段(25～150℃)和快速升温阶段(>150℃),并对其演变特性进行阐述。对临界升温速与粒径平均值以及临界升温速率与进气口氧浓度进行线性拟合,发现其间具有良好的线性关系。临界升温速率随粒径平均值、进气口氧浓度的增大而增大,表明较宽的粒度分级及较大的氧气浓度增加了煤炭的升温氧化诱导自燃的危险性。
In order to research the influence of particle sizes and oxygen concentrations on heating and oxidation of bituminous coal,a mesoscale low-temperature oxidation system supported by packed bed was established.By using this experiment system under 2 L/min inlet velocity,five size grading samples and different oxygen concentration heating and oxidation experiments were conducted from indoor temperature to 230℃.Based on low-temperature oxidation curve and taking acceleration mutation point as benchmark,three process variables including acceleration point temperature,critical time of spontaneous combustion,critical heating rate were obtained.The evolution process was divided into two stages:slowly heating stage(25～150℃)and rapid heating stage(>150℃),in addition,the evolution characteristics were expounded briefly.The linear relationship between critical heating rate and average particle size,critical heating rate and inlet oxygen concentration were linear fitted,and results showed good linear relationship.Results demonstrated that critical heating rate increasing with the increase of average particle size and inlet oxygen concentration,and indicate that the wider size grading and higher oxygen concentrations increase the risk of spontaneous combustion induced by heating of coal.
In order to research the influence of particle sizes and oxygen concentrations on heating and oxidation of bituminous coal,a mesoscale low-temperature oxidation system supported by packed bed was established.By using this experiment system under 2 L/min inlet velocity,five size grading samples and different oxygen concentration heating and oxidation experiments were conducted from indoor temperature to 230℃.Based on low-temperature oxidation curve and taking acceleration mutation point as benchmark,three process variables including acceleration point temperature,critical time of spontaneous combustion,critical heating rate were obtained.The evolution process was divided into two stages:slowly heating stage(25～150℃)and rapid heating stage(>150℃),in addition,the evolution characteristics were expounded briefly.The linear relationship between critical heating rate and average particle size,critical heating rate and inlet oxygen concentration were linear fitted,and results showed good linear relationship.Results demonstrated that critical heating rate increasing with the increase of average particle size and inlet oxygen concentration,and indicate that the wider size grading and higher oxygen concentrations increase the risk of spontaneous combustion induced by heating of coal.
引文
[1]王德明.煤氧化动力学理论与应用[M].北京:科学出版社,2012.
[2] SONG Z Y,HUANG X Y,LUO M G,et al. Experimental study on the diffusion-kinetics interaction in heterogeneous reaction of coal[J]. Journal of Thermal Analysis and Calorimetry,2017,129:1625-1637.
[3] SONG Z Y,KUENZER C. Coal fires in China over the last decade:A comprehensive review[J]. International Journal of Coal Geology,2014,133:72-99.
[4]胡源,宋磊,尤飞,等.火灾化学导论[M].北京:化学工业出版社,2006.
[5] AVILA C,WU T,LESTER E. Estimating the spontaneous combustion potential of coals using thermogravimetric analysis[J]. Energy&Fuels,2014,(8):1765-1773.
[6] HUANGFU W H,YOU F,SHAO Y,et al. Effects of oxygen concentrations and heating rates on non-isothermal combustion properties of jet coal in East China[J]. Procedia Engineering,2018,211:262-270.
[7]底翠翠,辛海会,李金帅.基于煤自燃倾向性的绝热氧化时间预测方法研究[J].科学技术与工程,2017,17(21):13-17.
[8]朱红青,刘丹龙,刘建荣.基于Arrhenius方程的煤的绝热氧化过程研究[J].中国安全科学学报,2016,26(7):63-67.
[9]王鑫阳,LUO Y,张勋,等.基于绝热氧化试验结果的煤自燃预测模型研究[J].中国安全科学学报,2017,27(6):67-72.
[10] GAO XZ,MAN CB,HU SJ,et al. Theoretical and experimental study on spontaneous ignition of lignite during the drying process in a packed bed[J]. Energy&Fuels,2012,26:6876-6887.
[11]邵玥.煤氧复合过程及其物理影响因素研究[D].南京:南京工业大学,2015.
[12]王文达.特征因素对煤热解及自燃特性影响分析[D].南京:南京工业大学,2017.
[13]王文达,尤飞,邵玥,等.粒度对煤自燃过程中特征温度的影响[J].消防科学与技术,2016,35(11):1511-1514.
[14]尤飞,皇甫文豪,王振华,等.基于热重分析的煤升温氧化及煤氧复合特性分析[J].安全与环境学报,2018,18(4):1312-1315.
[15]王海燕,李凯,高鹏.氧浓度对煤绝热氧化过程特征的影响[J].中国安全科学学报,2013,23(6):58-62.
[2] SONG Z Y,HUANG X Y,LUO M G,et al. Experimental study on the diffusion-kinetics interaction in heterogeneous reaction of coal[J]. Journal of Thermal Analysis and Calorimetry,2017,129:1625-1637.
[3] SONG Z Y,KUENZER C. Coal fires in China over the last decade:A comprehensive review[J]. International Journal of Coal Geology,2014,133:72-99.
[4]胡源,宋磊,尤飞,等.火灾化学导论[M].北京:化学工业出版社,2006.
[5] AVILA C,WU T,LESTER E. Estimating the spontaneous combustion potential of coals using thermogravimetric analysis[J]. Energy&Fuels,2014,(8):1765-1773.
[6] HUANGFU W H,YOU F,SHAO Y,et al. Effects of oxygen concentrations and heating rates on non-isothermal combustion properties of jet coal in East China[J]. Procedia Engineering,2018,211:262-270.
[7]底翠翠,辛海会,李金帅.基于煤自燃倾向性的绝热氧化时间预测方法研究[J].科学技术与工程,2017,17(21):13-17.
[8]朱红青,刘丹龙,刘建荣.基于Arrhenius方程的煤的绝热氧化过程研究[J].中国安全科学学报,2016,26(7):63-67.
[9]王鑫阳,LUO Y,张勋,等.基于绝热氧化试验结果的煤自燃预测模型研究[J].中国安全科学学报,2017,27(6):67-72.
[10] GAO XZ,MAN CB,HU SJ,et al. Theoretical and experimental study on spontaneous ignition of lignite during the drying process in a packed bed[J]. Energy&Fuels,2012,26:6876-6887.
[11]邵玥.煤氧复合过程及其物理影响因素研究[D].南京:南京工业大学,2015.
[12]王文达.特征因素对煤热解及自燃特性影响分析[D].南京:南京工业大学,2017.
[13]王文达,尤飞,邵玥,等.粒度对煤自燃过程中特征温度的影响[J].消防科学与技术,2016,35(11):1511-1514.
[14]尤飞,皇甫文豪,王振华,等.基于热重分析的煤升温氧化及煤氧复合特性分析[J].安全与环境学报,2018,18(4):1312-1315.
[15]王海燕,李凯,高鹏.氧浓度对煤绝热氧化过程特征的影响[J].中国安全科学学报,2013,23(6):58-62.