基于宽带关联k模型的气体辐射特性分析与计算  

Analysis and Calculation of Gas Radiation Characteristics Based on Wide Band Correlated-k Distribution Model

作　　者：阎维平[1] 米翠丽[1] 

机构地区：[1]华北电力大学能源与动力工程学院,电站设备状态监测与控制教育部重点实验室,保定071003

出　　处：《动力工程》2009年第12期1115-1122,共8页Power Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2009AA05Z310)

摘　　要：针对富氧燃烧方式下烟气中高浓度H2O和CO2混合气体的辐射换热问题,建立了一种改进的宽带关联(IWBCK)分布模型.为了验证IWBCK模型计算的有效性,首先选取不同配比的H2O/CO2混合气体进行计算分析,并与逐线计算和基于指数的宽带关联k分布模型进行对比,表明IWBCK模型对H2O/CO2混合气体的处理较合理,与逐线计算的结果更加接近;以某电站300MW燃煤锅炉为例,采用IWBCK模型计算了空气燃烧方式下三原子气体的辐射特性,并与前苏联锅炉机组热力计算标准的计算模型进行了对比分析,结果表明:两种模型的计算结果基本吻合,说明IWBCK模型对空气燃烧方式也是有效的.基于分区段热力计算的方法,采用IWBCK模型分别计算了该锅炉在空气燃烧方式和富氧燃烧方式(30%O2/70%CO2)下各区段三原子气体的吸收系数和发射率,结果表明:在不同温度下,富氧燃烧方式下三原子气体的吸收系数和发射率有不同程度的提高,辐射换热加强.Aiming at the radiative heat transfer problem of gas mixtures of high concentration water vapor and carbon dioxide in the flue gas under the oxygen-enriched combustion mode,an improved wide-band correlated-k（IWBCK） distribution model was developed.In order to verify the effectiveness of the IWBCK model,calculation and analysis were carried out for the gas mixtures of water vapor and carbon dioxide of different match.Calculation results were compared with results of line-by-line calculations and wide-band correlated-k distribution model based on the exponent.It is concluded that the IWBCK model is reasonable for the treatment of gas mixtures of H_2O and CO_2,and the results obtained by IWBCK model are much more close to the results obtained by line-byline calculation method.A 300 MW coal fired utility boiler was taken as an example,the triatomic gases radiation characteristics under air combustion mode were calculated using IWBCK model.Calculated results were compared with the results of the calculation model using thermodynamic calculation standard of the boiler developed by the previous Soviet Union.Results show that the calculation results of these two models basically conform to each other,which indicates that the IWBCK model is effective under air combustion mode.Based on the zoned thermal calculation method,the absorption coefficients and emissivities of the triatomic gases in each zone were calculated separately using the IWBCK model under air and oxygen-enriched combustion（30%O_2/70%CO_2）.Results show that the absorption coefficients and emissivities of the triatomic gases under oxygen-enriched combustion mode increase in different degree under different temperatures,which means the radiative heat transfer is intensified.

关 键 词：富氧燃烧 气体辐射 宽带关联k分布模型 分区段 吸收系数 发射率 

分 类 号：TK224.1[动力工程及工程热物理—动力机械及工程]