烟气对封闭煤场煤低温氧化反应的影响

Influence of waste flue gas on low temperature oxidation reaction of coal storaged in closed coal yard

为安全储存自燃倾向性强的煤种,对燃煤电厂在不同存煤方式下煤的低温氧化反应特性及锅炉出口烟气对封闭煤场煤低温氧化反应的影响进行了研究。结果表明,在传统存煤方式下,蒙煤在100℃下低温氧化反应48h和96h后发热量Qnet,daf分别降低了14.59%和15.87%,该存煤方式具有较好的氧气补充条件,不适合存储自燃倾向性强的煤;采用封闭煤场存煤时,蒙煤在100℃下低温氧化反应48h和96h后Qnet,daf分别仅降低了6.8%和8.35%,但在未装满煤时,封闭煤场对低温氧化反应的抑制效果有限;蒙煤在封闭煤场充烟气的存煤状态下,100℃低温氧化反应48h和96h后Qnet,daf分别降低了3.78%和5.8%,能够有效抑制煤低温氧化的进行。

The characteristics of low temperature on low temperature oxidation reaction of coal in oxidation reaction oI coal ann me et,ect oI waste itue gdb closed coal yard were investigated. The results show that, under the conventional coal storage way,the Mongolian coal＇s calorific value was reduced by 14.59% and 15.8% respectively after 48 hours＂ and 96 hours＂ low temperature oxidation at 100 ℃ ,indicating this way has better oxygen supply condition and is not suitable to store coals with spontaneous combustion tendency. When the closed coal yard was applied and with full storage, the Mongolian coal＇s calorific value was reduced by only 6.8% and 8.35% respectively after 48 hours＂ and 96 hours＇ low temperature oxidation at 100 ℃ ,indicating this way can inhibit the low-temperature oxidation of coal to a certain extent. But the inhibitory effect was limited when the closed coal yard is no full filled. When the closed coal yard was filled with waste flue gas,the Mongolian coal＇s calorific value was reduced by only 3.78% and 5.8% respectively after 48 hours＂ and 96 hours＇ low temperature oxidation at 100 ~C ,indicating this way can inhibit the low temperature oxidation reaction effectively. The waste gas not only can convert waste to useful resources and reduce inert gas cost, but also can ensure the operation safety of coal with spontaneous combustion tendency in the closed coal yard, since it can reduce the amount of air in the closed yard and isolate the out- side air to inhibit the low temperature oxidation reaction of coal.