煤粉燃烧过程中硫组分详细反应机理评估及简化  

Evaluation and simplification of detailed mechanism of sulfurspecies during pulverized coal combustion

作　　者：刘仕海 吕嗣晨 郝昊 李春玉[2] 周璐 马红和[1] LIU Shihai;LYU Sichen;HAO Hao;LI Chunyu;ZHOU Lu;MA Honghe(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China)

机构地区：[1]太原理工大学电气与动力工程学院,山西太原030024 [2]中国科学院山西煤炭化学研究所,山西太原030001

出　　处：《洁净煤技术》2021年第4期139-148,共10页Clean Coal Technology

基　　金：山西省科技重大专项资助项目(20201102006);山西省高等学校科技成果转化项目(2020CG009);国家自然科学基金资助项目(51706151)。

摘　　要：空气分级燃烧等低NO_(x)燃烧技术广泛应用于电厂锅炉,以降低炉膛出口NO_(x)浓度,但实际应用过程中会造成锅炉水冷壁腐蚀,严重影响煤粉锅炉的安全运行。为了准确预测锅炉水冷壁附近H_(2)S浓度,运用Chemkin软件对已建立的H_(2)S生成详细反应机理模型进行评估并简化。验证C/H/O详细反应机理与H_(2)S生成详细反应机理的耦合性,表明GRI-3.0能更好地预测煤粉富燃料燃烧过程中重要组分浓度分布;将耦合后的机理作为起始机理,与其他学者建立的硫详细反应机理进行比较,结果表明,本课题组的硫组分详细反应机理模型能够较好地描述煤粉燃烧过程中气态硫组分的演化,将CS_(2)作为重要硫组分进行研究,能够更好地预测硫组分浓度分布;通过简化结果比较,选择基于误差传递的直接关系图法(DRGEP)的简化结果作为硫组分简化反应机理,包含15个组分和28个基元反应,并在1373~1673 K验证,表明该简化机理适用于煤粉富燃料燃烧过程中硫组分浓度分布预测。Various low-NO_(x) combustion technologies,such as air-staged,are currently widely used in coal-fired boilers to reduce NO_(x) concentration at furnace outlet.However,in practical application,these technologies cause sulfidation corrosion of the boiler water-wall,and affect the safe operation of pulverized coal boiler.In order to accurately predict the concentration of H_(2)S near the boiler water wall,the gas-phase kinetics software Chemkin software was used to evaluate and simplify the established detailed reaction mechanism model of H_(2)S generation.First,in this paper,the coupling between the detailed reaction mechanism model of sulfur species and the detailed reaction mechanism of C/H/O was verified,which showed that GRI-3.0 could better predict the concentration distribution of important components in pulverized coal-fired boiler with air-staged.Then,the coupling mechanism model was taken as the initial mechanism and compared with other detailed sulfur reaction mechanisms.The results show that the detailed reaction mechanism model of sulfur species in our research group can better describe the evolution of gaseous sulfur species during pulverized coal combustion,and CS_(2) is considered as an important sulfur species to better predict the concentration distribution of sulfur species.Finally,by comparing the simplified results,the result obtained by the directed relation graph with error propagation(DRGEP)is selected as the simplified reaction mechanism model of the sulfur species,including 15 species and 28 reactions,which has been verifying in the temperature range of 1373-1673 K.The results show that reduced mechanism model can be applied to the prediction of the sulfur species concentration distribution during the fuel-rich combustion of pulverized coal.

关 键 词：煤粉燃烧 高温腐蚀 详细机理评估 机理简化 硫组分浓度预测 

分 类 号：TQ53[化学工程—煤化学工程] TK114[动力工程及工程热物理—热能工程]