摘要
在U+L型通风条件下,联络巷的存在对采空区遗煤自燃有重要的影响.为保证矿井安全生产,并为预防遗煤自燃提供依据,根据煤体低温氧化的反应机理,使用UDF将煤氧反应的机理编入FLUENT,对联络巷存在时采空区氧化升温带的分布规律进行多场耦合数值模拟研究.结果表明:联络巷的存在使采空区内风流场、氧浓度场及温度场都发生变化,氧化升温带不仅向回风侧偏移,而且向采空区深部移动且变宽;联络巷与工作面的距离影响氧化升温带的宽度,联络巷距工作面20 m时氧化升温带宽度最大约为25 m;反应进行10 d后,U+L型通风下采空区高温点的升温速率可达1.24 K·d-1,是U型通风的1.5倍,但联络巷相对工作面的位置对高温点几乎没有影响;与U型通风时相比,U+L通风时回风侧的温度场中联络巷口温度最高,而且比U型通风时相同坐标位置的温度平均每天高出4 K,随着联络巷与工作面距离的不断增加,联络巷口升温速率由0.1 K·d-1可升至0.9 K·d-1,这在整体温度场中虽然不属于高温区域,但具有很好的升温潜质.
Under the ventilation condition of U + L, a crossheading has important impact on spontaneous combustion of residual coal in a gob area. In order to ensure mine safety and obtain parameters to prevent spontaneous combustion of residual coal, on the basis of the mechanism of coal oxidation and using UDF to incorporate the reaction mechanism into FLUENT, multi-field coupling numerical simulation was performed to study the distribution law of the oxidization and heat accumulation zone in a gob with a cross- heading. The results show that the air flow field, oxygen concentration field and temperature field all change when the crossheading exists, the oxidization and heat aeeumulation zone not only offsets to the return-side but also becomes deeper and wider. The distance between the erossheading and working surface affects the width of the oxidization and heat accumulation zone, and when it is 20 m, the maximum width is approximately 25 m. After 10 d of reaetion, the heating rate at the high temperature point can reach 1.24K·d ' in the U + L ventilation system, which is 1.5 times that in the U ventilation system. However, the position of the crossheading has little effect on the high temperature point. The temperature nearby the crossheading is the highest in the return-side temperature field of the U + L ventilation system, and the average temperature is d K higher than the same location temperature in the U system per day. With increasing distance from the crossheading to working face, the heating rate in the crossheading rim increases from 0. 1 K·d-1 to 0. 9 K·d-1. Although the crossheading does not belong to the high temperature region in the whole temperature field, it has good warming potential.
出处
《工程科学学报》
EI
CSCD
北大核心
2016年第8期1050-1058,共9页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(51474017)
关键词
联络巷
采空区
氧化
升温
数值模拟
crossheading
gob areas
oxidization
temperature rise
numerical simulation