水分对煤低温氧化耗氧量影响的研究

水分在煤低温氧化过程中的作用具有两面性,根据其水分含量的多少促进或抑制煤的自燃。采用程序温升法研究了原煤样和50℃干燥煤样低温(≤100℃)氧化过程的耗氧量变化规律。对比分析表明,不同水分条件煤样耗氧量随温度的升高总体呈增加趋势,义马和朱仙庄原煤在初始阶段出现耗氧量减小,说明在100℃以前煤的升温特性主要受外在水分的影响;干燥后耗氧量相对原煤有显著增大,外在水分蒸发时吸收大量的热,以汽化潜热的方式带走,使煤体周围的热量不易聚集,且蒸汽压阻止了煤与空气中氧气的接触,外在水分在低温缓慢自热阶段主要起阻化作用;较低含水量与煤表面接触会释放一定量的润湿热而起到促进作用。

Analysis of Effect of Water Content to Oxygen Consumption of Coal Oxidation at Low-Temperature

Effect of water content to Coal Oxidation at Low-Temperature is different with different water content,catalyzing or suppressing coal oxidation.The change rules of oxygen consumption during the oxidation process of original coals and 50℃ dried coals were studied by using the temperature-programmed method.According to the relative analysis,find that oxygen consumption increased as the temperature increase to coal of different water content,oxygen consumption of yima and zhuxianzhuang original coals decreased at the first stage illustrate that coal warming characteristic mainly effect by water content before 100℃;relative to original coal,oxygen consumption of 50℃ dried coal have obviously increased,a large amount of heat was absorbed for the evaporation of exterior water in the manner of latent heat,which made the heat accumulation around the coals quite difficult.The vapor pressure prevented the contact of coal and oxygen.Thus,exterior water played an inhibition role at the low-temperatures slow oxidation stage.;quite water content will suppress coal oxidation process when contract to coal surface for release a certain amount of wetting heat.