塑料和生物质在循环床内燃烧特性的实验研究

Combustion of polyvinyl chloride and wood chips in a lab-scale circulating fluidized bed

以PVC和木屑分别作为塑料和生物质燃料的典型代表,通过实验研究观察影响燃烧过程产生的可燃气体CO、CH4、H2等分布特征的主要因素,充分分析了这两种燃料在循环流化床内的燃烧特性。实验结果表明:PVC和木屑表现出了强烈的挥发分燃烧特性,即挥发分在高温条件下迅速热解,然后随气流分布在整个炉膛内燃烧;炉膛内的温度呈"凸抛物线"型分布;木屑燃烧过程中,随着一次风率的提高,炉膛出口CH4、H2和CO浓度提高;PVC燃烧过程中,炉膛出口CO和CH4浓度极低。实验过程中还在实验台炉膛出口发现一定浓度的H2,与260 t/d垃圾焚烧的工业测试中发现的情况一致。

Polyvinyl chloride （PVC） and wood chips, as typical plastic and biomass fuels, were fed into a circulating fluidized-bed combustor without any other auxiliary fuel to analyze the main factors affecting the CO, CH4 and H2 distributions. The results show that PVC and wood chip combustion is a typical high volatiles combustion process characterized by fast volatiles pyrolysis and burning of the released combustible gas in the furnace. The results also show that the temperature variation along the furnace is represented as a convex parabola curve and that the CH4, H2 and CO concentrations at the furnace exit increase with increasing primary air ratio during wood chip combustion, while CO and CH4 were not detected during PVC combustion. The H2 presence at the furnace exit coincides with observations in a 260 t/d industrial incinerator test.