市政污泥与油茶壳混合燃烧特性研究

Study on mixed combustion characteristics of sewage sludge and camellia oleifera shell

采用热重分析法研究掺混比和升温速率对市政污泥和油茶壳混燃特性的影响,使用FlynnWall-Ozawa(FWO)和Kissinger-Akahira-Sunose(KAS)2种方法对样品的燃烧动力学进行建模,计算了各类样品的稳燃性指数和综合燃烧特性指数,分析了燃烧过程中混合燃料成分间的交互作用。结果表明:污泥掺混油茶壳后,混合燃料的燃尽温度明显降低,燃烧稳定性能和综合燃烧特性有明显改善;随着油茶壳掺混质量比从20%升至80%,燃尽温度从590℃下降到532℃,燃尽程度也逐渐变大,失质量由63.13%增加到92.19%,稳燃性指数和综合燃烧特性指数分别增加1.66和2.32倍;随着升温速率的增加,混合样品的燃尽温度、稳燃性指数和综合燃烧特性指数均提高,而燃尽程度变小,且着火温度无明显变化;污泥与油茶壳混合燃烧各组分间发生了交互现象,在挥发分燃烧阶段表现为抑制作用,而固定碳燃烧阶段表现为促进作用;FWO法和KAS法计算污泥的平均表观活化能分别为122.32、118.08 k J/mol,油茶壳的平均表观活化能分别为166.46、164.94 k J/mol,混合样品的平均表观活化能随着油茶壳掺混质量比的增加而增大。

The effects of blending ratio and heating rate on co-combustion characteristics of municipal sludge and camellia oleifera shell were studied by thermogravimetric analysis,and the combustion kinetics of the samples were modeled by two methods,Flynn-Wall-Ozawa(FWO)and Kissinger-Akahira-Sunose(KAS).Moreover,the flammability index and comprehensive combustion characteristic index of various samples were calculated,and the interaction between the mixed fuel components during the combustion process was analyzed.The results show that,the burnout temperature of the mixed fuel significantly reduced,and the combustion stability and comprehensive combustion characteristics were significantly improved after the sludge was mixed with camellia oleifera shell.With the increase of the mass blending ratio of camellia oleifera shell from 20%to 80%,the burnout temperature decreased from 590℃to 532℃,the burnout degree gradually increased,the mass loss increased from 63.13%to 92.19%,and the flammability index and comprehensive combustion characteristic index increased by 1.66 and 2.32 times,respectively.The interaction between the components of sludge and camellia oleifera shell mixed combustion occurred,which showed an inhibition effect in the volatile combustion stage,while a promoting effect in the fixed carbon combustion stage.The average apparent activation energies of sludge calculated by the FWO method and KAS method were 122.32 kJ/mol and 118.08 kJ/mol,respectively,and the average apparent activation energies of the camellia oleifera shell were 166.46 kJ/mol and 164.94 kJ/mol,respectively.The average apparent activation energy of the mixed samples increased with the mass mixing ratio of camellia oleifera shell.