空气系数对煤粉预热解燃烧特性的影响分析  

Investigation of the effect of air coefficient on the combustion characteristics of pulverized coal pre-pyrolysis

作　　者：姚国家 王志 苏昂 冯东阁 唐宏[1] 孙灵芳[1] YAO Guojia;WANG Zhi;SU Ang;FENG Dongge;TANG Hong;SUN Lingfang(School of Automation Engineering,Northeast Electric Power University,Jilin 132012,Jilin,China;School of Low-Carbon Energy and Power Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China)

机构地区：[1]东北电力大学自动化工程学院,吉林吉林132012 [2]中国矿业大学低碳能源与动力工程学院,江苏徐州221116

出　　处：《化工学报》2025年第3期1243-1252,共10页CIESC Journal

基　　金：国家自然科学基金项目(52376096)。

摘　　要：煤粉预热解燃烧方法是降低氮氧化物和稳定燃烧的有效途径。为了探究煤粉预热解燃烧特性,建立了适用于煤粉预热解燃烧的RPM-MSRM(random pore model-multiphase surface reaction model)模型,并探究了空气系数对热解气生成和燃料氮转化过程的影响。研究结果表明:煤粉预热解后挥发分热解和部分焦炭气化生成大量热解气[23%~38%(体积分数)]和高温焦炭(>800℃),烟气射流刚性增强,有助于提高燃烧稳定性;空气系数是影响煤粉预热解特征的主要因素,空气系数与出口温度呈正相关关系,与热解气浓度呈负相关关系;本装置的最佳预热解空气系数为0.3,此时装置出口NO_(x)浓度最低为26.82 mg/m^(3)(@6%O_(2),标准工况),燃料氮的还原效率最高为99.51%。因此,煤粉预热解燃烧应尽量保持在最佳空气系数下进行以达到最佳的降氮效果。Pulverized coal pre-pyrolysis combustion method is an effective way to reduce NO_(x)and stabilize combustion.To investigate the pre-pyrolysis combustion characteristics of pulverized coal,the RPM-MSRM model(random pore model-multiphase surface reaction model)for pulverized coal pre-pyrolysis combustion was established,and the effects of air coefficient on generation of pyrolysis gases and conversion of fuel nitrogen were investigated.The results show that after pulverized coal pre-pyrolysis,the volatile matter is pyrolyzed and part of the coke is gasified to generate a large amount of pyrolysis gas[23%—38%(vol)]and high-temperature coke(>800℃),and the flue gas jet rigidity is enhanced,which helps to improve the combustion stability.The rigidity of the flue gas jet is enhanced,which helps to improve the combustion stability.The air coefficient is the main factor affecting the characteristics of pulverized coal pre-pyrolysis.The air coefficient is positively correlated with outlet temperature and negatively correlated with pyrolysis gas concentration.The optimum pre-pyrolysis air coefficient for the device in this paper is 0.3.The lowest NO_(x)concentration at the unit outlet is 26.82 mg/m^(3)(@6%O_(2),standard operating conditions),and the highest reduction efficiency of fuel nitrogen is 99.51%.Therefore,pulverized coal pre-pyrolysis combustion should be maintained at the optimum air coefficient conditions to achieve the best nitrogen reduction.

关 键 词：煤燃烧 热解 计算流体力学 燃料氮 焦炭模型 

分 类 号：TK16[动力工程及工程热物理—热能工程]