易自燃特厚煤层综放面采空区注氮防灭火技术研究与应用
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摘要
我国国有煤矿自然发火危险矿井已占60%,由于煤炭自燃导致的优质煤损失量已达42亿吨以上,现在仍以每年2000～3000万吨的速度增加,煤矿每年都因火灾造成人员的重大伤亡,造成数十亿元的经济损失。随着综采放顶煤开采方法的推广,在高产高效的同时,也给易自燃特厚煤层自然火灾的防治带来了严峻的考验。在综放开采中,采空区冒落大,往往留有大量的松散遗煤,加之漏风严重,使得遗煤很容易与采空区漏风流中的氧气发生氧化反应,从而导致采空区自燃火灾的发生,严重威胁矿工的生命安全和煤矿的安全生产。
本文从煤炭自燃机理入手,研究了易自燃特厚煤层综放面采空区自然发火特点及其规律;通过对煤样自燃特性、指标气体和自燃倾向性的实验研究,掌握了该矿煤层自然发火的特性,确定了预测预报的指标,建立了以指标气体分析法为主的早期预测预报体系;以注氮防灭火理论及技术为依据,结合同煤集团塔山矿8202综放工作面实际情况,计算出各注氮参数,制定出合理的采空区注氮防灭火系统,并辅以束管监测系统,对采空区气体变化进行监测,及时反馈、调整各注氮参数,提高注氮防灭火系统的惰化效率。
通过对同煤集团塔山矿8202综放工作面采空区气体近一年的监测,分析总结数据,并对采空区内气体变化规律、注氮惰化时间和采空区“三带”变化进行研究,得出了在连续注氮条件下,采空区内O_2、CO、N_2、CH_4和CO2的变化规律、初次惰化时间和持续惰化时间以及注氮前后采空区“三带”的具体变化情况。最后根据注氮防灭火惰化指标,在对监测数据统计分析的基础上,做出注氮防灭火效果的客观评价,更好的指导防灭火工作,保证矿山的安全生产。
得出的主要结论如下:
1、易自燃特厚煤层综放面采空区自燃有以下特点:自燃一般发生在距煤体暴露面一定距离的深部,高温区域隐蔽且范围较大;煤自燃过程中,随煤温升高,高温点总是逆着风流移动;采空区自燃火灾灭火难度大,火区启封后易于复燃。
2、同煤集团塔山矿8202综放面采空区防灭火应以CO作为指标性气体,并辅以C_2H_6、C_2H_4、C_3H-8、C_2H_2来掌握煤炭自燃情况。CO浓度突然增加说明煤已经发生氧化反应, C_2H_4和C_3H_8的出现表明煤温已经超过140℃,而C_2H_2的出现则说明煤温已经超过190℃。
3、塔山矿8202综采面在连续注氮情况下,氧浓度随采空区深度的增加明显降低,最终稳定在3%左右,保证了综采工作面的顺利推进;注氮量越大,氧气浓度下降的梯度越大;注氮对采空区氧气浓度的影响程度具有一定的范围。
4、利用综采放顶煤技术开采特厚、大采高、易自燃煤层时,综采面回风流中出现一定量的CO是其很明显的一个特点。5、采空区惰化时间大致可划分为两个阶段:初次惰化时间和二次惰化时间。即便采空区内氧浓度很快降低到安全浓度指标,采空区内遗煤的低温氧化仍然在继续,只有当采空区内的氧浓度下降到3%左右并持续一段时间以后,遗煤的低温氧化才得到有效的控制。
6、在连续注氮条件下,采空区“三带”宽度分布为:散热带20~30m,氧化带16~38m,窒息带距综采面68m以外;由于工作面供风量和漏风量都较大,对散热带宽度影响不大,氧化带在注氮后缩短了约120m,对比注氮前后,窒息带提前了172m左右。
Presently, 60% of the state-owned coal mines have already been in danger because of the coal spontaneous combustion. The loss of high grade coal due to the coal spontaneous combustion has been up to 4.2 billion tons. Worsely, the loss has been growing by 2000-3000 million tons every year. Moreover, the heavy casualties caused by the fire hazard annually lead to heavy toll of lives and billions of yuan in economic losses. Not only does the coal spontaneous combustion waste coal resources, but also leads to the serious environmental and ecological problems.The fully mechanized sublevel caving mining with high output and efficiency, brings out a serious challenge on the prevention and extinguishment of extra thick seam spontaneous combustion. During caving, the collapsed zone is large, resulting in a lot of loose coal left, which is easy to be oxidized by the oxygen in air leakage flow with a result of gob fire, seriously threatening the safety of miners and production
Starting from the mechanism of the coal spontaneous combustion, the characteristics and laws of the spontaneous combustion of a extra thick seam in the gob were studied in the paper; With knowing the characteristics of the coal spontaneous combustion and confirming the prediction index,the early stage prediction system based on the gas index analysis was established; combining the practical situation of the Tashan Coal Mine 8202 caving face, the parameters of the nitrogen injection were calculated to develop a reasonable nitrogen injection system to prevent the gob fire in light of the nitrogen injection theory and technology, which was supported by the beam control monitoring system. The nitrogen injection efficiency was improved by monitoring the gas changes in gob and adjusting the nitrogen injection parameters timely.
With the monitoring on the gas changes in Tashan Coal Mine 8202 caving gob almost in one year and the data analysis, the pattern of gob gas changes, the nitrogen injection time and the gob of "three zones" change were studied, obtaining the change pattern of O_2, CO, N_2, CH_4 and CO_2 in gob, initial inerting time, continuous injection time and the change of "Three Zones" before and after the nitrogen injection were obtained. Finally, , based on the statistical analysis of monitoring data and the fir inerting index after the nitrogen injection, the objective evaluation was concluded to guide thefire prevention and ensure the mine safety.
The conclusions are as follows:
1. The spontaneous combustion of extra thick seam in the gob is of the following characteristics: the spontaneous combustion of coal usually occurs in the certain distance to the surface with the hidden high temperature zone and the large region; the high-temperature point is always going against flow movement; during the coal spontaneous combustion when the coal temperature rising; Gobit is difficult to extinguish the fire in gob, and the fire is easy to take place again after unsealing.
2. CO should be used as an indicator for the fire prevention in Tashan Mine 8202 Gob , supplemented by C_2H_6, C_2H_4, C_3H_8 and C_2H_2 to control the spontaneous combustion of coal. The CO concentration rising in a sudden showed that the oxidation of coal has already occurred. The emergence C_2H_4 and C_3H_8 showed the coal temperature over 140℃, while the emergence of C_2H_2 shows the coal temperature higher than 190℃.
3. The oxygen concentration decreased with the mining depth increasing and eventually stabilized at around 3% to ensure the smooth progress of the fully mechanized 8202 mining face under the continuous nitrogen injection ; the greater the nitrogen injected, the greater the oxygen concentration gradient declined; the nitrogen injection in gob had a certain influencing range on the oxygen concentration.
4. There is a certain amount of CO in the air flow in is an obvious feature when caving the extra thick spontaneous combustion coal with greater mining height .
5. Gob inerting time could be divided into two stages such as the first and the second inerting time. The residual mined coal in gob was still in the low-temperature oxidation even if the oxygen concentration decreased rapidly to a safe concentration. Only when the oxygen concentration decreased to about 3% and continued for some time, the low-temperature oxidation of residual coal could be effectively controlled.
6. Under continuous nitrogen injection, gob "three zones" width distribution were 20-30m for heat radiation zone, 16-38m for oxidation zone, out of 68m from the mining face for suffocative zone; Because of the great amount of air flow and air leakage, the nitrogen injection had little effect on the width of heat radiation zone, while the width of the oxidation zone shortened about 120m and the suffocative zone shifted forward about 172m or soafter nitrogen injection.
本文从煤炭自燃机理入手,研究了易自燃特厚煤层综放面采空区自然发火特点及其规律;通过对煤样自燃特性、指标气体和自燃倾向性的实验研究,掌握了该矿煤层自然发火的特性,确定了预测预报的指标,建立了以指标气体分析法为主的早期预测预报体系;以注氮防灭火理论及技术为依据,结合同煤集团塔山矿8202综放工作面实际情况,计算出各注氮参数,制定出合理的采空区注氮防灭火系统,并辅以束管监测系统,对采空区气体变化进行监测,及时反馈、调整各注氮参数,提高注氮防灭火系统的惰化效率。
通过对同煤集团塔山矿8202综放工作面采空区气体近一年的监测,分析总结数据,并对采空区内气体变化规律、注氮惰化时间和采空区“三带”变化进行研究,得出了在连续注氮条件下,采空区内O_2、CO、N_2、CH_4和CO2的变化规律、初次惰化时间和持续惰化时间以及注氮前后采空区“三带”的具体变化情况。最后根据注氮防灭火惰化指标,在对监测数据统计分析的基础上,做出注氮防灭火效果的客观评价,更好的指导防灭火工作,保证矿山的安全生产。
得出的主要结论如下:
1、易自燃特厚煤层综放面采空区自燃有以下特点:自燃一般发生在距煤体暴露面一定距离的深部,高温区域隐蔽且范围较大;煤自燃过程中,随煤温升高,高温点总是逆着风流移动;采空区自燃火灾灭火难度大,火区启封后易于复燃。
2、同煤集团塔山矿8202综放面采空区防灭火应以CO作为指标性气体,并辅以C_2H_6、C_2H_4、C_3H-8、C_2H_2来掌握煤炭自燃情况。CO浓度突然增加说明煤已经发生氧化反应, C_2H_4和C_3H_8的出现表明煤温已经超过140℃,而C_2H_2的出现则说明煤温已经超过190℃。
3、塔山矿8202综采面在连续注氮情况下,氧浓度随采空区深度的增加明显降低,最终稳定在3%左右,保证了综采工作面的顺利推进;注氮量越大,氧气浓度下降的梯度越大;注氮对采空区氧气浓度的影响程度具有一定的范围。
4、利用综采放顶煤技术开采特厚、大采高、易自燃煤层时,综采面回风流中出现一定量的CO是其很明显的一个特点。5、采空区惰化时间大致可划分为两个阶段:初次惰化时间和二次惰化时间。即便采空区内氧浓度很快降低到安全浓度指标,采空区内遗煤的低温氧化仍然在继续,只有当采空区内的氧浓度下降到3%左右并持续一段时间以后,遗煤的低温氧化才得到有效的控制。
6、在连续注氮条件下,采空区“三带”宽度分布为:散热带20~30m,氧化带16~38m,窒息带距综采面68m以外;由于工作面供风量和漏风量都较大,对散热带宽度影响不大,氧化带在注氮后缩短了约120m,对比注氮前后,窒息带提前了172m左右。
Presently, 60% of the state-owned coal mines have already been in danger because of the coal spontaneous combustion. The loss of high grade coal due to the coal spontaneous combustion has been up to 4.2 billion tons. Worsely, the loss has been growing by 2000-3000 million tons every year. Moreover, the heavy casualties caused by the fire hazard annually lead to heavy toll of lives and billions of yuan in economic losses. Not only does the coal spontaneous combustion waste coal resources, but also leads to the serious environmental and ecological problems.The fully mechanized sublevel caving mining with high output and efficiency, brings out a serious challenge on the prevention and extinguishment of extra thick seam spontaneous combustion. During caving, the collapsed zone is large, resulting in a lot of loose coal left, which is easy to be oxidized by the oxygen in air leakage flow with a result of gob fire, seriously threatening the safety of miners and production
Starting from the mechanism of the coal spontaneous combustion, the characteristics and laws of the spontaneous combustion of a extra thick seam in the gob were studied in the paper; With knowing the characteristics of the coal spontaneous combustion and confirming the prediction index,the early stage prediction system based on the gas index analysis was established; combining the practical situation of the Tashan Coal Mine 8202 caving face, the parameters of the nitrogen injection were calculated to develop a reasonable nitrogen injection system to prevent the gob fire in light of the nitrogen injection theory and technology, which was supported by the beam control monitoring system. The nitrogen injection efficiency was improved by monitoring the gas changes in gob and adjusting the nitrogen injection parameters timely.
With the monitoring on the gas changes in Tashan Coal Mine 8202 caving gob almost in one year and the data analysis, the pattern of gob gas changes, the nitrogen injection time and the gob of "three zones" change were studied, obtaining the change pattern of O_2, CO, N_2, CH_4 and CO_2 in gob, initial inerting time, continuous injection time and the change of "Three Zones" before and after the nitrogen injection were obtained. Finally, , based on the statistical analysis of monitoring data and the fir inerting index after the nitrogen injection, the objective evaluation was concluded to guide thefire prevention and ensure the mine safety.
The conclusions are as follows:
1. The spontaneous combustion of extra thick seam in the gob is of the following characteristics: the spontaneous combustion of coal usually occurs in the certain distance to the surface with the hidden high temperature zone and the large region; the high-temperature point is always going against flow movement; during the coal spontaneous combustion when the coal temperature rising; Gobit is difficult to extinguish the fire in gob, and the fire is easy to take place again after unsealing.
2. CO should be used as an indicator for the fire prevention in Tashan Mine 8202 Gob , supplemented by C_2H_6, C_2H_4, C_3H_8 and C_2H_2 to control the spontaneous combustion of coal. The CO concentration rising in a sudden showed that the oxidation of coal has already occurred. The emergence C_2H_4 and C_3H_8 showed the coal temperature over 140℃, while the emergence of C_2H_2 shows the coal temperature higher than 190℃.
3. The oxygen concentration decreased with the mining depth increasing and eventually stabilized at around 3% to ensure the smooth progress of the fully mechanized 8202 mining face under the continuous nitrogen injection ; the greater the nitrogen injected, the greater the oxygen concentration gradient declined; the nitrogen injection in gob had a certain influencing range on the oxygen concentration.
4. There is a certain amount of CO in the air flow in is an obvious feature when caving the extra thick spontaneous combustion coal with greater mining height .
5. Gob inerting time could be divided into two stages such as the first and the second inerting time. The residual mined coal in gob was still in the low-temperature oxidation even if the oxygen concentration decreased rapidly to a safe concentration. Only when the oxygen concentration decreased to about 3% and continued for some time, the low-temperature oxidation of residual coal could be effectively controlled.
6. Under continuous nitrogen injection, gob "three zones" width distribution were 20-30m for heat radiation zone, 16-38m for oxidation zone, out of 68m from the mining face for suffocative zone; Because of the great amount of air flow and air leakage, the nitrogen injection had little effect on the width of heat radiation zone, while the width of the oxidation zone shortened about 120m and the suffocative zone shifted forward about 172m or soafter nitrogen injection.
引文
[1]邬剑明.煤矿自燃火灾治理关键技术的研究与应用[J].中国安全科学学报, 1998(4).
[2]邬剑明.煤自燃火灾防治新技术及矿用新型密闭堵漏材料的研究与应用[D].太原:太原理工大学, 2008.
[3]王俊峰,李有忠.注氮防火时采空区气体变化与“三带”分布状况的检测[J].太原理工大学学报, 2000, 31(6): 638-641.
[4]王俊峰,邬剑明,吴玉国.基于火源探测的凝胶灭火技术在西铭矿49309工作面的应用.中国煤炭, 2008, 34(1): 49-50.
[5]王省身,张国枢.矿井火灾防治[M].徐州:中国矿业大学出版社, 1990. 16-34.
[6]吴玉国,邬剑明,王俊峰.煤层自燃指标气体的试验研究.中国煤炭, 2007, (4): 40-42.
[7]刘文岭,张润泉,刘瑞,邬剑明.火区下煤层开采的安全决策技术.煤矿安全, 2004, 35(3): 25-26.
[8] YAN Hong, WU JIANMING, ZHANG Xuehu, ZHANG Yan, WEI Liqiao, LIU Xuguang, XU Bingshe. Synthesis of Magnesium Hydroxide Nanoneedles and Short Nanorods on Polymer Dispersant Template. Journal of Material Research, 2007, 22(9): 2544-2549.
[9] Garcia P. The use of differential scanning calorimetry to identify coals susceptible to spontaneous combustion.Thermoehemieal acta, 1999, 336(l-2): 41-46.
[10]聂鸿元.综合防灭火技术在高瓦斯矿井近距离煤层火灾中的研究应用[D].太原:太原理工大学, 2007.
[11]陆卫东.浅埋厚煤层综放开采注氮防火技术研究[D].阜新:辽宁工程技术大学, 2006.
[12] WU JIANMING, YAN Hong, ZHANG Xuehu, WEI Liqiao, LIU Xuguang, XU Bingshe. Magnesium hydroxide nanoparticles synthesized in water-in-oil microemulsions. J. Colloid Inter. Sci., 2008, 324, 167-171.
[13]何学秋.安全工程学[M].北京:中国矿业大学出版社, 2000, 6.
[14]徐精彩,张辛亥,文虎.煤层自燃胶体防灭火理论与技术[M].北京:煤炭工业出版社, 2003: 1-8.
[15]邓军,徐精彩,陈晓坤.煤自燃机理及预测理论研究进展[J].辽宁工程技术大学学报. 2003(8), 22(4): 454-459.
[16] J.B.Stott and X.D.Cheng. Measure the tendence of coal to fire spontaneously. Colliery Guardian, 1992, 240(1), 9-16
[17]彭本信.应用热分析技术研究煤的氧化自燃过程[[J].煤炭工程师, 1992, (2): l-10.
[18] Arief A. S., Gillies A.D.S. Apractical test of coal spontaneous combustion In Proceedding of the AusIMM Annual conference, Newcastle, Melbourne, Australia: The Austanlasian Institute of Mining and Metallurgy, 1995, 111-114.
[19] Jones R G and Townend D T, J. Soc. Chem. Ind. London, 1995, 108: 197.
[20]高桑功,为田博宪,田代襄等.关于煤自然发火的研究——煤的破碎性与自燃的关系[J].探矿与保安, 1977, (3): 9-13.
[21] Schmidt L. D. In Chem.of Coal Util.(Ed.Lowry H H.), New York: Wiley, 1945, 627-633.
[22]高桑功,为田博宪,田代襄,等.关于煤自然发火的研究——煤的碳素、灰与水含量与着火温度的关系[J].探矿与保安, 1978, (2): 1-4.
[23]戴中蜀,郑的晖,马立红.低煤化度煤低温热解脱氧后结构的变化[[J].燃料化学学报, 1999, 27(3): 256-261.
[24]范天吉.矿井防灭火综合技术手册[M].吉林:吉林音像出版社.
[25] Kuuk A., Y.Kadioglu, M.S.Gulaboglu, A study of spontaneous combustion characteristics of Turkish lignite: Particle size, moisture of coal, humidity of air [J], Combustion and Flame, 2003, (133), 255-261.
[26]陈全,王省身.综放采场自然发火规律及注氮防灭火技术研究[J].煤炭学报, 1996, 21(6): 618-623.
[27]周令昌.综放开采采空区液氮降温防灭火数值模拟研究[D].阜新:辽宁工程技术大学, 2006.
[28]吴玉国,高泉,刘文岭,邬剑明.矿井安全保障制度及管理的模糊综合评价方法.中国煤炭, 2004, 30(1): 51-52.
[29] Cliiff D., Davis, R.Bennet, A.Galvin, G& Clarkson, F.Large scale laboratory testing of the spontaneous combustibility of Australia coals. In Queensland Mining Industry Health 8Safety conferenc, 1998, Yeppoon: 175-179. Bresbance, Australia: Queensland mining council.
[30]李宗翔.综放采空区防灭火注氮数值模拟与参数确定[J].中国安全科学学报, 2003, 13(2): 53-57.
[31]马汉鹏,王德明,何启林.注氮对综采面采空区内O2的浓度和“三带”宽度的影响[J].煤矿安全, 2006, (1): 11-13.
[2]邬剑明.煤自燃火灾防治新技术及矿用新型密闭堵漏材料的研究与应用[D].太原:太原理工大学, 2008.
[3]王俊峰,李有忠.注氮防火时采空区气体变化与“三带”分布状况的检测[J].太原理工大学学报, 2000, 31(6): 638-641.
[4]王俊峰,邬剑明,吴玉国.基于火源探测的凝胶灭火技术在西铭矿49309工作面的应用.中国煤炭, 2008, 34(1): 49-50.
[5]王省身,张国枢.矿井火灾防治[M].徐州:中国矿业大学出版社, 1990. 16-34.
[6]吴玉国,邬剑明,王俊峰.煤层自燃指标气体的试验研究.中国煤炭, 2007, (4): 40-42.
[7]刘文岭,张润泉,刘瑞,邬剑明.火区下煤层开采的安全决策技术.煤矿安全, 2004, 35(3): 25-26.
[8] YAN Hong, WU JIANMING, ZHANG Xuehu, ZHANG Yan, WEI Liqiao, LIU Xuguang, XU Bingshe. Synthesis of Magnesium Hydroxide Nanoneedles and Short Nanorods on Polymer Dispersant Template. Journal of Material Research, 2007, 22(9): 2544-2549.
[9] Garcia P. The use of differential scanning calorimetry to identify coals susceptible to spontaneous combustion.Thermoehemieal acta, 1999, 336(l-2): 41-46.
[10]聂鸿元.综合防灭火技术在高瓦斯矿井近距离煤层火灾中的研究应用[D].太原:太原理工大学, 2007.
[11]陆卫东.浅埋厚煤层综放开采注氮防火技术研究[D].阜新:辽宁工程技术大学, 2006.
[12] WU JIANMING, YAN Hong, ZHANG Xuehu, WEI Liqiao, LIU Xuguang, XU Bingshe. Magnesium hydroxide nanoparticles synthesized in water-in-oil microemulsions. J. Colloid Inter. Sci., 2008, 324, 167-171.
[13]何学秋.安全工程学[M].北京:中国矿业大学出版社, 2000, 6.
[14]徐精彩,张辛亥,文虎.煤层自燃胶体防灭火理论与技术[M].北京:煤炭工业出版社, 2003: 1-8.
[15]邓军,徐精彩,陈晓坤.煤自燃机理及预测理论研究进展[J].辽宁工程技术大学学报. 2003(8), 22(4): 454-459.
[16] J.B.Stott and X.D.Cheng. Measure the tendence of coal to fire spontaneously. Colliery Guardian, 1992, 240(1), 9-16
[17]彭本信.应用热分析技术研究煤的氧化自燃过程[[J].煤炭工程师, 1992, (2): l-10.
[18] Arief A. S., Gillies A.D.S. Apractical test of coal spontaneous combustion In Proceedding of the AusIMM Annual conference, Newcastle, Melbourne, Australia: The Austanlasian Institute of Mining and Metallurgy, 1995, 111-114.
[19] Jones R G and Townend D T, J. Soc. Chem. Ind. London, 1995, 108: 197.
[20]高桑功,为田博宪,田代襄等.关于煤自然发火的研究——煤的破碎性与自燃的关系[J].探矿与保安, 1977, (3): 9-13.
[21] Schmidt L. D. In Chem.of Coal Util.(Ed.Lowry H H.), New York: Wiley, 1945, 627-633.
[22]高桑功,为田博宪,田代襄,等.关于煤自然发火的研究——煤的碳素、灰与水含量与着火温度的关系[J].探矿与保安, 1978, (2): 1-4.
[23]戴中蜀,郑的晖,马立红.低煤化度煤低温热解脱氧后结构的变化[[J].燃料化学学报, 1999, 27(3): 256-261.
[24]范天吉.矿井防灭火综合技术手册[M].吉林:吉林音像出版社.
[25] Kuuk A., Y.Kadioglu, M.S.Gulaboglu, A study of spontaneous combustion characteristics of Turkish lignite: Particle size, moisture of coal, humidity of air [J], Combustion and Flame, 2003, (133), 255-261.
[26]陈全,王省身.综放采场自然发火规律及注氮防灭火技术研究[J].煤炭学报, 1996, 21(6): 618-623.
[27]周令昌.综放开采采空区液氮降温防灭火数值模拟研究[D].阜新:辽宁工程技术大学, 2006.
[28]吴玉国,高泉,刘文岭,邬剑明.矿井安全保障制度及管理的模糊综合评价方法.中国煤炭, 2004, 30(1): 51-52.
[29] Cliiff D., Davis, R.Bennet, A.Galvin, G& Clarkson, F.Large scale laboratory testing of the spontaneous combustibility of Australia coals. In Queensland Mining Industry Health 8Safety conferenc, 1998, Yeppoon: 175-179. Bresbance, Australia: Queensland mining council.
[30]李宗翔.综放采空区防灭火注氮数值模拟与参数确定[J].中国安全科学学报, 2003, 13(2): 53-57.
[31]马汉鹏,王德明,何启林.注氮对综采面采空区内O2的浓度和“三带”宽度的影响[J].煤矿安全, 2006, (1): 11-13.