氧气浓度对劣质煤掺混生活污泥燃烧特性的影响

采用热重分析方法研究了劣质煤掺混生活污泥在氧气浓度20％、30％、50％、70％、90％条件下的燃烧特性和动力学特性.随着氧气浓度的增加,失重率曲线DTG向低温区移动.对着火温度、失重率峰值以及对应温度、燃尽温度、混合物燃烧综合特性指数进行了对比分析,并对固定碳燃烧阶段的表观活化能进行了计算,结果表明,提高氧气浓度能显著改善燃烧条件,表观活化能随着氧气浓度的提高而增大,随掺混比的增加而减小.定义燃烧促进因子C.E.F.(Combustion Enhancement Factor)表征燃料内外部燃烧促进条件,在固定碳燃烧段,燃烧促进因子随氧气浓度增加迅速增大,表明增大氧气浓度对燃烧具有良好促进作用.燃烧促进因子C.E.F.与表观活化能之间具有动力学补偿效应.

Influence of oxygen concentration on combustion characteristics of inferior coal and sludge mixture

Combustion characteristics and thermal dynamic characteristics of inferior coal and core board mixture in O₂ and N₂ atmosphere were studied with O₂ concentration of 20％, 30％, 50％, 70％, 90％ respectively. With the increase of O₂ concentration, DTG curves tend to move to lower temperature region. Also, ignition temperature, maximum weight loss rate and its corresponding temperature, the temperature of burnout, and synthetic combustion factor of mixture, are compared. The results indicate that O₂ concentration can significantly improve the combustion conditions. Apparent activation energy of the fixed carbon combustion section is put into the calculation and analysis, which shows that the apparent activation energy increases with the increasing O₂ concentration. In order to quantize combustion condition internal and external, definition of combustion enhancement factor(C.E.F.) is put forward. In selected fixed carbon combustion segment, C.E.F. increases rapidly with the increase in O₂ concentration, which proves the positive role of oxygen concentration on combustion. There are kinetic compensation effect between C.E.F. and apparent activation energy.