二氧化碳和氮气对煤自燃性能影响的对比试验研究

Comparative research on the influence of dioxide carbon and nitrogen on performance of coal spontaneous combustion

为研究二氧化碳和氮气对于抑制煤自燃的不同效果,设计了煤自燃程序升温静态试验和动态试验,测试了在不同试验条件下煤的耗氧速度和一氧化碳的产生速度,验证了二氧化碳气体和氮气对煤的氧化反应速度产生不同的影响,得到煤样在分别通入空气、氮气-空气混合气体和二氧化碳-空气混合气体后的表观活化能,分别为38.952 75,40.600 59和46.795 35 k J/mol。可见惰性气体可以增大煤样的表观活化能,但是氮气-空气的混合气体只是略微增大了煤样的表观活化能,而二氧化碳-空气混合气体则显著增大了煤样的表观活化能,说明在通入二氧化碳气体情况下煤样更不易自燃,二氧化碳比氮气具有更好的抑制煤炭自燃的能力。

Both carbon dioxide and nitrogen can be used as inert gas to prevent the fire disaster in mine goaf. However,carbon dioxide and nitrogen have different physicochemical property and have somewhat different effects on preventing mine fire. In order to investigate the different effects of carbon dioxide and nitrogen inhibiting spontaneous combustion,this study designed a temperature program experiment on spontaneous combustion. The corresponding data was obtained by the means of importing standard air,nitrogen-air mixed gas or carbon dioxide-air mixed air into the tank of coal sample（ note the oxygen concentration in the two mixed gases is equal to each other）. The experiment was divided into static and dynamic temperature program experiments. The static temperature program experiment verified the different influence of carbon dioxide and nitrogen on the speed of coal＇s oxidation reaction. To be precise,the existence of carbon dioxide and nitrogen did have different influence on the speed of oxygen consumption of coal as well as the speed of carbon monoxide. Importing air,nitrogen-air mixed gas and carbon dioxide-air mixed gas into temperature program,the apparent activation energy were 38. 952 75,40. 600 59 and 46. 795 35 kJ / mol,respectively. Therefore,it is clear that inert gas can increase the apparent activation energy of coal sample,while nitrogen-air mixed gas canslightly increase the apparent activation energy of coal sample and carbon dioxide-air mixed gas can significantly increase the apparent activation energy of coal sample. This demonstrates that coal sample cannot easily be ignited by importing carbon dioxide-air mixed gas and carbon dioxide has more capacity of inhibiting coal spontaneous combustion compared to nitrogen-air mixed gas.