催化型微粒捕集器碳烟分布及其影响因素
|
摘要
建立了催化型柴油机微粒捕集器(CDPF)的数学模型,通过相关试验验证了模型的正确性,分析了CDPF排气参数和结构参数对碳烟分布的影响。研究结果表明:壁面层的碳烟质量浓度呈现先急剧上升后缓慢减少的特点;滤饼层的碳烟分布呈现两端高、轴向无量纲位置x=0.3左右的位置最低的分布特性。随着排气参数(温度、流量、氧体积分数、NO2体积分数)的增大,壁面积累碳烟质量浓度减少,其中温度的影响最大;排气流量的增大会使滤饼层碳烟分布最低点位置逐渐向前端移动。结构参数(长径比、进出口孔径比、孔密度)对滤饼层碳烟分布形状影响较大,随着结构参数的增大,滤饼层碳烟分布趋于不均匀,其中孔密度的变化对滤饼层碳烟分布影响最大,孔密度的增大会使最低点位置向后端移动;进出口孔径的增大使最低点位置向前端移动。
A mathematical model of Catalytic Diesel Particulate Filter(CDPF)was built up.The exhaust parameters and structure parameters were analyzed,and the model was validated through experimental data.The results show that the mass in the filter wall increases steeply and then decreases slowly.Soot distribution in the cake layer has a minimum thickness for appropriately 30%of the total channel length.While,the edges at the inlet and outlet have the maximum thickness.The exhaust parameters,including temperature,flow rate,the concentration of O2 and the concentration of NO2,mainly influence the thickness of soot distribution by influencing performance of the NO2 assisted regeneration.The temperature has the largest influence,and the thickness of soot distribution in the cake layer is more sensitive to the concentration of NO2 than O2.The structure parameters,including the ratio of length to diameter,the ratio of inlet diameter to outlet diameterand channel density have significant effects on the shape of the soot distribution in the cake layer.With the increase in the structure parameters,the soot distribution tends to be uneven,and the channel density has the largest impact,which means the position of the lowest point tends to move to the rear end,while the increase in the ratio of inlet diameter to outlet diameter leads the point to move to the front end.
A mathematical model of Catalytic Diesel Particulate Filter(CDPF)was built up.The exhaust parameters and structure parameters were analyzed,and the model was validated through experimental data.The results show that the mass in the filter wall increases steeply and then decreases slowly.Soot distribution in the cake layer has a minimum thickness for appropriately 30%of the total channel length.While,the edges at the inlet and outlet have the maximum thickness.The exhaust parameters,including temperature,flow rate,the concentration of O2 and the concentration of NO2,mainly influence the thickness of soot distribution by influencing performance of the NO2 assisted regeneration.The temperature has the largest influence,and the thickness of soot distribution in the cake layer is more sensitive to the concentration of NO2 than O2.The structure parameters,including the ratio of length to diameter,the ratio of inlet diameter to outlet diameterand channel density have significant effects on the shape of the soot distribution in the cake layer.With the increase in the structure parameters,the soot distribution tends to be uneven,and the channel density has the largest impact,which means the position of the lowest point tends to move to the rear end,while the increase in the ratio of inlet diameter to outlet diameter leads the point to move to the front end.
引文
[1]Resitoglu I A,Altinisik K,Keskin A.The pollutant emissions from diesel-engine vehicles and exhaust aftertreatment systems[J].Clean Technologies and Environmental Policy,2015,17(1):15-27.
[2]帅石金,唐韬,赵彦光,等.柴油车排放法规及后处理技术的现状与展望[J].汽车安全与节能学报,2012,3(3):200-217.Shuai Shi-jin,Tang Tao,Zhao Yan-guang,et al.State of the art and outlook of diesel emission regulations and aftertreatment technologies[J].Journal of Automotive Safety and Energy,2012,3(3):200-217.
[3]Hesterberg T W,Long C M,Bunn W B,et al.Health effects research and regulation of diesel exhaust:an historical overview focused on lung cancer rick[J].Inhalation Toxicology,2012,24:1-45.
[4]Hesterberg T W,Long C M,Sax S N,et al,Particulate matter in new technology diesel exhaust(NTDE)is quantitatively and qualitatively very different from that found in traditional diesel exhaust(TDE)[J].Journal of the Air&Waste Management Association,2011,61(9):894-913.
[5]Guan B,Zhan R,Lin H,et al.Review of the stateof-the-art of exhaust particulate filter technology in internal combustion engines[J].Journal of Environmental Management,2015,154:225-258.
[6]李志军,杨士超,焦鹏昊,等.催化型微粒捕集器主被动再生性能数值模拟[J].农业机械学报,2014,45(5):37-43.Li Zhi-jun,Yang Shi-chao,Jiao Peng-hao,et al.Computational investigation in active and passive regeneration characteristics of catalytic particulate filter[J].Transactions of the Chinese Society for Agriculture Machinery,2014,45(5):37-43.
[7]马荣,何超,李加强,等.NO2对柴油机微粒捕集器再生特性的影响机理[J].车用发动机,2013(3):71-74.Ma Rong,He Chao,Li Jia-qiang,et al.Influence of NO2on DPF regeneration characteristics[J].Vehicle Engine,2013(3):71-74.
[8]Wu G J,Kuznetsov A V,Jasper W J.Distribution characteristics of exhaust gases and soot particles in a wall-flow ceramics filter[J].Journal of Aerosol Science,2011,42(7):447-461.
[9]Bisset E J.Mathematical model of the thermal regeneration of a wall-flow monolith diesel particulate filter[J].Chemical Engineering Science,1984,39:1233-1244.
[10]Konstandopoulos A,Kostoglou M.Periodically reversed flow regeneration of diesel particulate traps[C]∥SAE Paper,1999-01-0469.
[11]Haralampous O A,Koltsakis G C.Back-diffusion modeling of NO2in catalyzed diesel particulate filters[J].Industrial&Engineering Chemistry Research,2004,43(4):875-883.
[12]Konstandopoulos A,Kostoglou M,Skaperdas E,et al.Fundamental studies of diesel particulate filters:transient loading,regeneration and aging[C]∥SAE Paper,2000-01-1016.
[13]刘洪岐,高莹,姜鸿澎,等.NO2扩散作用对催化型微粒捕集器再生的影响[J].农业机械学报,2016,47(12):354-360,366.Liu Hong-qi,Gao Ying,Jiang Hong-peng,et al.Effects of NO2diffusion on catalyst diesel particulate filter regeneration[J].Transactions of the Chinese Society for Agriculture Machinery,2016,47(12):354-360,366.
[14]Mohammed H,Lakkireddy V,Johnson J,et al.An experimental and modeling study of a diesel oxidation catalyst and a catalyzed diesel particulate filter using a 1-D 2-Layer model[C]∥SAE Paper,2006-01-0466.
[15]Bensaid S,Marchisio D L,Fino D,et al.Modelling of diesel particulate filtration in wall-flow traps[J].Chemical Engineering Journal,2009,154(1-3):211-218.
[2]帅石金,唐韬,赵彦光,等.柴油车排放法规及后处理技术的现状与展望[J].汽车安全与节能学报,2012,3(3):200-217.Shuai Shi-jin,Tang Tao,Zhao Yan-guang,et al.State of the art and outlook of diesel emission regulations and aftertreatment technologies[J].Journal of Automotive Safety and Energy,2012,3(3):200-217.
[3]Hesterberg T W,Long C M,Bunn W B,et al.Health effects research and regulation of diesel exhaust:an historical overview focused on lung cancer rick[J].Inhalation Toxicology,2012,24:1-45.
[4]Hesterberg T W,Long C M,Sax S N,et al,Particulate matter in new technology diesel exhaust(NTDE)is quantitatively and qualitatively very different from that found in traditional diesel exhaust(TDE)[J].Journal of the Air&Waste Management Association,2011,61(9):894-913.
[5]Guan B,Zhan R,Lin H,et al.Review of the stateof-the-art of exhaust particulate filter technology in internal combustion engines[J].Journal of Environmental Management,2015,154:225-258.
[6]李志军,杨士超,焦鹏昊,等.催化型微粒捕集器主被动再生性能数值模拟[J].农业机械学报,2014,45(5):37-43.Li Zhi-jun,Yang Shi-chao,Jiao Peng-hao,et al.Computational investigation in active and passive regeneration characteristics of catalytic particulate filter[J].Transactions of the Chinese Society for Agriculture Machinery,2014,45(5):37-43.
[7]马荣,何超,李加强,等.NO2对柴油机微粒捕集器再生特性的影响机理[J].车用发动机,2013(3):71-74.Ma Rong,He Chao,Li Jia-qiang,et al.Influence of NO2on DPF regeneration characteristics[J].Vehicle Engine,2013(3):71-74.
[8]Wu G J,Kuznetsov A V,Jasper W J.Distribution characteristics of exhaust gases and soot particles in a wall-flow ceramics filter[J].Journal of Aerosol Science,2011,42(7):447-461.
[9]Bisset E J.Mathematical model of the thermal regeneration of a wall-flow monolith diesel particulate filter[J].Chemical Engineering Science,1984,39:1233-1244.
[10]Konstandopoulos A,Kostoglou M.Periodically reversed flow regeneration of diesel particulate traps[C]∥SAE Paper,1999-01-0469.
[11]Haralampous O A,Koltsakis G C.Back-diffusion modeling of NO2in catalyzed diesel particulate filters[J].Industrial&Engineering Chemistry Research,2004,43(4):875-883.
[12]Konstandopoulos A,Kostoglou M,Skaperdas E,et al.Fundamental studies of diesel particulate filters:transient loading,regeneration and aging[C]∥SAE Paper,2000-01-1016.
[13]刘洪岐,高莹,姜鸿澎,等.NO2扩散作用对催化型微粒捕集器再生的影响[J].农业机械学报,2016,47(12):354-360,366.Liu Hong-qi,Gao Ying,Jiang Hong-peng,et al.Effects of NO2diffusion on catalyst diesel particulate filter regeneration[J].Transactions of the Chinese Society for Agriculture Machinery,2016,47(12):354-360,366.
[14]Mohammed H,Lakkireddy V,Johnson J,et al.An experimental and modeling study of a diesel oxidation catalyst and a catalyzed diesel particulate filter using a 1-D 2-Layer model[C]∥SAE Paper,2006-01-0466.
[15]Bensaid S,Marchisio D L,Fino D,et al.Modelling of diesel particulate filtration in wall-flow traps[J].Chemical Engineering Journal,2009,154(1-3):211-218.