摘要
针对连续式捆烧设备在连续进料过程中,秸秆捆连续稳定燃烧性能差、挥发分气体燃烧不充分、秸秆捆难燃尽,而导致热效率低、排放高的问题,该研究基于分级燃烧原理与秸秆捆燃烧特性,在设计计算过程中,对燃烧、换热、配风系统等较为重要设计参数给出了合理的参考值,并通过烟气预热干燥秸秆捆、增加挥发分二次燃尽的三级风、往复炉排增加捆间间隙等方式提高秸秆捆的燃烧性能。设备试制后,利用玉米秸秆捆为燃料开展了热工与排放性能试验。试验结果表明,连续式秸秆捆烧锅炉的平均热效率为80.37%,颗粒物、NOx、SO_(2)平均排放质量浓度分别为48、197、7 mg/m^(3),环保与能效指标均符合设计要求与国家标准。并对建立的采暖示范工程进行排放、污染物等测算,结果表明采用秸秆捆烧供暖单位面积可减少标煤使用量23.1 kg/m^(2),CO_(2)当量排放量58 kg/m^(2)。该研究能为秸秆能源化利用与北方清洁区域供暖提供技术支撑,助力农业农村领域碳达峰、碳中和的目标实现。
A large amount of straw has been widely returning in China.For example,89 million tons with a comprehensive utilization rate of 86.79%in 2017.The rest of the unutilized straw can be treated via abandonment or burning in the field,even though it can cause heavy pollution.Alternatively,the crop straws can be utilized as fuels for hot water boilers in cleaning heating.By contrast,there are 400 million tons of standard coal consumed annually for heating in North China.A large amount of coal burning has led to a substantial increase in the emission of pollutants,especially in rural areas in winter.But,there are still so many challenges in the combustion system of straw.In this study,a continuously baled straw combustion boiler was designed to improve the thermal efficiency and emission with the rated thermal power of 1.4 MW suitable for small-scale heating.Some parameters were also determined for the furnace combustion chamber,grate,air distribution,and heat exchange system.A reciprocating grate was designed to increase the gap of the fuel,particularly for the full contact between fuel and oxygen.A state-of-the-art air staging was utilized to design the combustion system for the best distribution of primary and second air volume.The total air excess coefficient was set as 1.4.The reason was that the pollute emission was the largest when the air excess coefficients were around 1.0 and 1.8 in the primary and second combustion chamber,respectively.The heat transfer surfaces were assumed as the radiate and convection heating exchanging system,which were mainly absorbed the heat in the process of fuel combustion,thereby maintaining the furnace in the process at a suitable temperature.The temperature values of the combustion chamber,flue gas at the combustion chamber outlet,flue gas at the chimney outlet were about 1314,972,and 147,respectively.The heat and emission tests were conducted under the national standard after the boiler was completed.The field tests were carried out in the Tieling County,Liaoning province of Chin
作者
邓云
贾吉秀
姚宗路
赵立欣
霍丽丽
杨武英
郭洪伟
Deng Yun;Jia Jixiu;Yao Zonglu;Zhao Lixin;Huo Lili;Yang Wuying;Guo Hongwei(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Tieling Zhongyuan Environmental Protection&Equipment Co.,Ltd,Tieling 112000,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2021年第21期252-258,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
中国农业科学院科技创新工程
财政部和农业农村部:国家现代农业产业技术体系资助。
关键词
排放
热效率
设计
捆烧
清洁供暖
emissions
thermal efficiency
design
baled straw combustion
clean heating
