WU Xiaofeng;FAN Weidong;

• 1:School of Mechanical and Power Engineering
• 2:Shanghai Jiao Tong University

Abstract：

In oxy-fuel combustion,flue gas is mainly composed of CO_2 and H_2O because the recycled flue gas is used as diluent instead of N_2 in the air. CO_2 and H_2O have an intensive radiation ability as non-polar triatomic molecule while N_2 has no radiation ability,which leads to the change of gas radiation characteristics in oxy-fuel combustion. In the numerical simulation,gas radiation model is an important sub model. Several modified gas radiation models have been proposed for applying to oxy-fuel combustion,but the effect of different gas radiation model on the numerical simulation of oxy-fuel combustion in different conditions has not been unified. In order to research the effect of gas radiation model on the simulation results of combustion heat transfer in different sizes of furnace with gas or coal combustion,one new gas radiation model considering the effect of CO and other six typical models in the literatures were coupled into the numerical simulation by user defined function programming. The results show that: in the oxy-gas combustion,the flame structure is affected by gas radiation models. Meanwhile,the combustion temperature distribution changes and the difference between the results of different models can reach 500 K. Radiation heat transfer between gas and wall is also controlled by gas radiation models. The effect of gas radiation models on flame zone is rather large while it is ignored in the non-flame zone. In the oxy-coal combustion,when the effective radiation layer thickness is around 0.3 m such as in a 100 kW_(th) down-fired furnace,gas radiation models almost have no effect on the coal combustion numerical simulation results. This may be because particle radiation plays a dominant role in the radiation heat transfer calculation.When the path length is around 16 m such as in a 1 000 MW tower type boiler,gas radiation models have a large effect on the combustion temperature and species concentration. The temperature difference can reach 100 K. However,the gas radiation model has no effect on the simulation results in the non-flame zone in middle of furnace.

Key Words： oxy-fuel combustion;coal combustion;gas radiation;weighted sum of gray gas model

Abstract:

Keywords:

Foundation: 国家重点研发计划资助项目(2018YFB0605301)

Authors: WU Xiaofeng;FAN Weidong;

DOI: 10.13226/j.issn.1006-6772.CCUS20090601

References：

• [1]刘宇，曹江，朱声宝．挑战全球气候变化——二氧化碳捕集与封存[J]．前沿科学，2010,4(1):40-51.LIU Yu,CAO Jiang,ZHU Shengbao.Challenging climate change:Carbon dioxide capture and storage[J].Frontier Science,2010,4(1):40-51．
• [2]潘一，梁景玉，吴芳芳，等．二氧化碳捕捉与封存技术的研究与展望[J]．当代化工，2012,41(10):1072-1075,1078.PAN Yi,LIANG Jingyu,WU Fangfang,et al.Research and prospect of the carbon dioxide capture and storage technology[J].Contemporary Chemical Industry,2012,41 (10):1072-1075,1078．
• [3]何铮，李瑞忠．未来20年中国能源需求预测[J]．当代石油石化，2016,24(9):1-8.HE Zheng,LI Ruizhong.Prediction of China's energy consumption in the future 20 year[J].Petroleum&Petrochemical Today,2016,24(9):1-8．
• [4]张卫东，张栋，田克忠．碳捕集与封存技术的现状与未来[J]．中外能源，2009,14(11):7-14.ZHANG Weidong,ZHANG Dong,TIAN Kezhong.Carbon capture and sequestration technology[J].Sino-global Energy,2009,14(11):7-14．
• [5]HEES J,ZABRODIEC D,MASSMEYER A,et al.Experimental investigation into the influence of the oxygen concentration on a pulverized coal swirl flame in oxy-fuel atmosphere[J].Fuel,2019,240:64-74．
• [6]JIANG X,HUANG X,LIU J,et al.NOxEmission of fine-and superfine-pulverized coal combustion in O2/CO2atmosphere[J].Energy&Fuels,2010,24:6307-6313．
• [7]ZHONG S,ZHANG F,PENG Z,et al.Roles of CO2and H2O in premixed turbulent oxy-fuel combustion[J].Fuel,2018,234:1044-1054．
• [8]WALL T,STANGER R,LIU Y.Gas cleaning challenges for coalfired oxy-fuel technology with carbon capture and storage[J].Fuel,2013,108:85-90．
• [9]EDGE P,GHAREBAGHI M,IRONS R,et al.Combustion modelling opportunities and challenges for oxy-coal carbon capture technology[J].Chemical Engineering Research and Design,2011,89:1470-1493．
• [10]EDGE P,GUBBA S R,MA L,et al.LES modelling of air and oxy-fuel pulverised coal combustion-impact on flame properties[J].Proceedings of the Combustion Institute,2011,33:2709-2716．
• [11]EDGE P J,HEGGS P J,POURKASHANIAN M,et al.An integrated computational fluid dynamics-process model of natural circulation steam generation in a coal-fired power plant[J].Computers&Chemical Engineering,2011,35:2618-2631．
• [12]GUO J,HU F,JIANG X,et al.Experimental and numerical investigations on heat transfer characteristics of a 35 MW oxy-fuel combustion boiler[J].Energy Procedia,2017,114,481-489．
• [13]GUO J,HU F,JIANG X,et al.Effects of gas and particle radiation on IFRF 2.5 MW swirling flame under oxy-fuel combustion[J].Fuel,2020,263:116634．
• [14]GUO J,LIU Z,HUANG X,et al.Experimental and numerical investigations on oxy-coal combustion in a 35 MW large pilot boiler[J].Fuel,2017,187:315-327．
• [15]GUO J,LIU Z,WANG P,et al.Numerical investigation on oxy-combustion characteristics of a 200 MWe tangentially fired boiler[J].Fuel,2015,140:660-668．
• [16]WALL T,LIU Y,SPERO C,et al.An overview on oxyfuel coal combustion:State of the art research and technology development[J].Chemical Engineering Research and Design,2009,87:1003-1016．
• [17]WALL T F.Combustion processes for carbon capture[J].Proceedings of the Combustion Institute,2007,31:31-47．
• [18]GUO J,LI X,HUANG X,et al.A full spectrum k-distribution based weighted-sum-of-gray-gases model for oxy-fuel combustion[J].International Journal of Heat and Mass Transfer,2015,90:218-226．
• [19]BECHER V,GOANTA A,SPLIETHOFF H.Validation of spectral gas radiation models under oxyfuel conditions-Part C:Validation of simplified models[J].International Journal of Greenhouse Gas Control,2012,11:34-51．
• [20]KANGWANPONGPAN T,CORRA da Silva R,KRAUTZ H J.Prediction of oxy-coal combustion through an optimized weighted sum of gray gases model[J].Energy,2012,41:244-251．
• [21]SMITH T F,SHEN Z F.Evaluation of coefficients for the weighted sum of gray gases model,ASME and American Institute of Chemical Engineers[C].20th National Heat Transfer Conference,1982,104:602-608．
• [22]冯艳．富氧气氛下辐射模型对煤粉燃烧数值模拟影响特性的研究[D]．马鞍山:安徽工业大学，2017:73-76.FENG Yan.Study on the influence of radiation model on the numerical simulation of pulverized coal combustion in oxygen-enriched atmosphere[D].Maanshan:Anhui University of Technology,2017:73-76．
• [23]YIN C,JOHANSEN L C R,ROSENDAHL L A,et al.New weighted sum of gray gases model applicable to computational fluid dnamics(CFD) modeling of oxy-fuel combustion:Derivation,validation,and implementation[J].Energy&Fuels,2010,24:6275-6282．
• [24]JOHANSSON R,ANDERSSON K,LECKNER B,et al.Models for gaseous radiative heat transfer applied to oxy-fuel conditions in boilers[J].International Journal of Heat and Mass Transfer,2010,53:220-230．
• [25]KANGWANPONGPAN T,FRANA F H R,CORRA da Silva R,et al.New correlations for the weighted-sum-of-gray-gases model in oxy-fuel conditions based on HITEMP 2010database[J].International Journal of Heat and Mass Transfer,2012,55:7419-7433．
• [26]BORDBAR M H,W CEL G,HYPPNEN T..A line by line based weighted sum of gray gases model for inhomogeneous CO2-H2O mixture in oxy-fired combustion[J].Combustion and Flame,2014,161:2435-2445．
• [27]齐永刚．富氧燃烧过程炉膛烟气辐射特性与辐射传热的数值模拟[D]．武汉:华中科技大学，2011.QI Yonggang,Numerical simulation of radiative heat transfer and radiative properties of gases in oxy-fuel conditions[D].Wuhan:Huazhong University of Science and Technology,2011．
• [28]姚放，加压富氧下煤粉燃烧过程的数值模拟[D]．北京:北京交通大学，2014.YAO Fang,Numerical simulation of the pressurized oxycoal combustion process[D].Beijing:Beijing Jiao Tong University,2014．
• [29]谈和平，夏新林，刘林华，等．红外辐射特性与传输的数值计算:计算热辐射学[M]．哈尔滨:哈尔滨工业大学出版社，2006:69-86.TAN Heping,XIA Xinlin,LIU Linhua,et al,Numerical calculation of infrared radiation characteristics and transmission:Calculation of thermal radiation science[M].Harbin:Harbin Institute of Technology Press,2006:69-86．
• [30]HOTTEL H C,SAROFIM A F.Radiative transfer[M].New York:Mc Graw-Hill Book Company,1967．
• [31]YIN C,ROSENDAHL L A,KR S K.Chemistry and radiation in oxy-fuel combustion:A computational fluid dynamics modeling study[J].Fuel,2011,90:2519-2529．
• [32]YIN C.Prediction of air-fuel and oxy-fuel combustion through a generic gas radiation property model[J].Applied Energy,2017,189:449-459．
• [33]JONES W P,LINDSTEDT R P.Global reaction schemes for hydrocarbon combustion[J].Combustion and Flame,1988,73:233-249．
• [34]TOPOROV D,BOCIAN P,HEIL P,et al.Detailed investigation of a pulverized fuel swirl flame in CO2/O2atmosphere[J].Combustion and Flame,2008,155:605-618．
• [35]WU X,FAN W,LIU Y,et al.Numerical simulation research on the unique thermal deviation in a 1 000 MW tower type boiler[J].Energy,2019,173:1006-1020.