摘要
根据玉米秸秆捆烧特性,设计出整体玉米秸秆打捆燃料燃烧差热试验台。通过对玉米秸秆打捆燃料在不同供风温度(18℃、90℃)和不同供风量(过剩空气系数α分别取值0.7、1.1、1.5)工况下进行热重测试分析,建立了燃烧过程的动力学模型,求解出热解动力学参数:活化能和频率因子。研究表明:玉米秸秆打捆燃料燃烧的热重曲线、微商热重曲线总体变化特征是相似的,燃烧前期燃烧速度变化较快,中期逐渐变慢,后期趋于平稳;分析了燃烧温度和供风量对秸秆打捆燃料燃烧速度的影响,实现合理配风下的控温燃烧,挥发份的析出速度均匀适中,燃烧相对平稳;捆烧动力学模型的建立,完善了生物质打捆燃料的燃烧理论,可供有关生物质打捆燃料打捆设备及燃烧设备的设计人员参考。
The differential thermal experiments of entire cornstalk bale combustion were designed according to the characteristics of cornstalk bale combustion. A dynamic model of the combustion process was developed through analyzing thermo-gravimetric data collected from the combustion of cornstalk bales under different air supply temperature （18℃-90℃） and different air flow with excess air coefficientαwith 0.7, 1.1 or 1.5. The pyrolysis kinetic parameters modeled include activation energy and frequency factor. The activation energy and frequency factor adopted from Kissinger method were 94.4 kJ/mol and 70.6 kJ/mol, 1.2×106 and 3.3×106 respectively. Their correlation coefficient was greater than 0.99. Model predicted results and measured data were essentially identical. The model performed well. In this experiment the cornstalk bale combustion process were divided as three parts：endothermic and dehydration,precipitation of volatile and the combustion reaction,fixed carbon combustion reaction. The initial temperature of the straw of the volatile gradually decreased with increasing heating rate, volatilization is releasing slowly. First, it reached in kinetic region, gradually into transition region, finally in diffusion region with volatilization combustion. Final temperature of the precipitation of volatile and the peak temperature of the weight loss rate deviated to the side of high temperature. The result showed that the TG and DTG characteristic curve of cornstalk bale combustion were similar overall. The burning velocity changed rapidly in the early period of combustion, it slowed down gradually in the middle period and finally ended towards a stable condition. According to the combustion experiments of cornstalk bales, the higher the combustion temperature was, the faster volatilization separated out. The dominant factors that influenced the combustion efficiency are the combustion temperature and air flow. The controlled temperature combustion under rational air distribution and dissolution velocity of
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2013年第24期218-226,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
河南省基础与前沿技术研究(122300410086)
关键词
秸秆
燃料
模型
捆烧特性
热重分析
straw, fuels, models, bales combustion characteristics, thermo-gravimetric analysis
