大颗粒木质成型燃料燃烧过程烟气排放特性  

Characteristics of flue gas emissions during large wood pellet combustion

作　　者：陈国华[1] 李运泉[1] 彭浩斌 李越胜 江志铭 

机构地区：[1]华南理工大学机械与汽车工程学院,广州510640 [2]广东省特种设备检测研究院顺德检测院,顺德528300

出　　处：《农业工程学报》2015年第7期215-220,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：广东省教育部产学研结合项目(2012B091000156);广东省省部产学研合作专项资金项目(2013B090500111)

摘　　要：选用大颗粒木质燃料为研究对象,通过管式加热炉对单颗粒木质燃料进行燃烧试验,研究不同空气流量和温度下木质燃料燃烧过程CO、NO、SO_2等气体动态排放特性。试验结果表明:800℃时,挥发分着火时间滞后,着火前即有CO随挥发分析出,CO排放浓度曲线呈双峰状;随着温度升高,CO析出峰明显变窄,从挥发分析出至焦炭燃烧完成所需时间缩短:NO排放浓度及其排放量在温度为900℃时达到最大值,燃料N至NO的转化率最高可达41.79%,随着温度升高和燃烧过程还原性气氛增强,NO析出浓度及其排放量减少,转化率可低至12.32%;木质燃料充分燃烧时,几乎无SO_2排出,S主要转化为硫酸盐固存于灰分中或于高温下随烟气排出;贫氧燃烧状态下,S02析出主要源自挥发分析出初期有机硫的分解、氧化,但燃料中更多的s以H2S、CaS等形式排出。Due to the influence of the mass and heat transfer, some obvious differences in flue gas emissions may occur during the combustion of wood powders and pellet. However, many studies report on the characteristics of flue gas emissions during wood powder combustion, and researches on the single wood pellet combustion and its flue gas emission are limited. The aim of this work was to obtain dynamic data on the release of CO, NO, and SO2 during single large wood pellet combustion by performing experiments in a tube furnace under different temperatures （800, 900, 1 000, 1 100, and 1 200~C） and air flow rates （3, 4, and 5 L/min）. The results from the experiment can serve as an important reference for efficient and clean combustion of biomass. The total emissions and their conversions from biomass combustion can be quantified with these data. The experimental results showed that CO emission curve present a double-peak shape at 800~C, mainly because of its slow devolatilization and combustion in low temperature. With increasing temperature, CO emission time decreased, indicating that it needed shorter time during devolatilization and char burnout. Because of sufficient burning, the peak CO concentrations and total CO emissions almost decreased as the temperature grown in 4, 5 L/min air flow rate. NO was released to the gas phase in significant amounts at 900~C, while decreased with increasing temperature or reducing air flow rate. A part of NO was transformed to N2 with the reductive gas of CO as the temperature increased. At temperaaxres of 1 100 and 1 200~C, NO forming through HCN and NH3 declined because of inadequate oxygen supply in 3 L/min air flow rate. The change tendencies of NO emissions in 4 L/min air flow rate were similar to the change tendencies in 5 L/min air flow rate, probably associated with CO emissions in 4, 5 L/min air flow rate. Fuel-N conversion rate reached the minimum and maximum values （12.32%, 41.79%） in 3 L/min air flow rate under the combustion temperature of 1 200~C and 5 L/min ai

关 键 词：生物质 燃烧 烟气排放 木质燃料 NO SO2 

分 类 号：TK6[动力工程及工程热物理—生物能]