| Citation: | LIANG H M,XU H X,LEI X X,et al.Influence of non-uniform distribution of catalysts on the characteristics of ship SCR system[J].Journal of Environmental Engineering Technology，2024，14（3）：836-845 doi: 10.12153/j.issn.1674-991X.20230713
|
Selective catalytic reduction (SCR) systems are typically used to reduce nitrogen oxides (NOx) emitted from diesel engine exhaust emissions. To further improve its de-NOx performance, firstly, a three-dimensional numerical simulation model was established. The non-uniform distribution of the catalyst was achieved by changing the porosity in the SCR converter, and the impact of the non-uniform distribution of the catalyst under different engine loads on the flow, mass transfer, and heat transfer performance of the SCR system was investigated. Secondly, the impact of the non-uniform distribution of the catalyst on the performance of the SCR system was examined and compared with that of the uniform distribution. Finally, based on the principle of field synergy, the influence of velocity and temperature fields on the heat transfer process in the SCR system was analyzed. The results indicate that the non-uniform distribution of catalysts can improve the performance of SCR systems. At 25% engine load, compared to a uniform distribution, the pressure drop of Case P-R5 is reduced by 165 Pa, the conversion efficiency of NOx is increased by 0.8%, and the escape of ammonia is reduced by 7 mg/L. In addition, the temperature gradient of Case P-R5 is higher than the maximum peak of the temperature gradient of the catalyst with uniform porosity, indicating that there is less energy transferred to the outside. The non-uniform distribution of the catalyst structure can maintain the temperature of the catalytic region, improve the catalyst activity, and facilitate de-NOx reactions.
| [1] |
屠星月, 邵社刚, 张潇天, 等. 基于时空数据挖掘的大气重污染传输过程时空规律分析[J]. 环境工程技术学报,2023,13(3):940-948. doi: 10.12153/j.issn.1674-991X.20220696
TU X Y, SHAO S G, ZHANG X T, et al. Analysis of spatiotemporal laws in the transmission process of atmospheric heavy pollution based on spatiotemporal data mining[J]. Journal of Environmental Engineering Technology,2023,13(3):940-948. doi: 10.12153/j.issn.1674-991X.20220696
|
| [2] |
胡杰, 张磊, 李敏, 等. SCR催化器热失活数值仿真[J]. 内燃机学报,2015,33(5):72-78.
HU J, ZHANG L, LI M, et al. Numerical simulation on SCR catalyst thermal inactivation[J]. Transactions of CSICE,2015,33(5):72-78.
|
| [3] |
钟超. 柴油机微粒捕集器再生对选择性催化还原性能影响研究[D]. 长沙: 湖南大学, 2020.
|
| [4] |
CHEN L, LIAO Y F, XIN S R, et al. Simultaneous removal of NO and volatile organic compounds (VOCs) by Ce/Mo doping-modified selective catalytic reduction (SCR) catalysts in denitrification zone of coal-fired flue gas[J]. Fuel,2020,262:116485. doi: 10.1016/j.fuel.2019.116485
|
| [5] |
ZHANG Z Q, TIAN J, LI J T, et al. Effects of different mixture ratios of methanol-diesel on the performance enhancement and emission reduction for a diesel engine[J]. Processes,2021,9(8):1366. doi: 10.3390/pr9081366
|
| [6] |
张文强. 柴油机尿素SCR系统反应特性的研究[D]. 长沙: 湖南大学, 2011.
|
| [7] |
ZHANG G W, YAN H Y, LI T H, et al. Relation analysis on emission control and economic cost of SCR system for marine diesels[J]. Science of the Total Environment,2021,788:147856. doi: 10.1016/j.scitotenv.2021.147856
|
| [8] |
LEI Z G, WEN C P, CHEN B H. Optimization of internals for selective catalytic reduction (SCR) for NO removal[J]. Environmental Science & Technology,2011,45(8):3437-3444.
|
| [9] |
YE J D, LV J S, TAN D L, et al. Numerical analysis on enhancing spray performance of SCR mixer device and heat transfer performance based on field synergy principle[J]. Processes,2021,9(5):786. doi: 10.3390/pr9050786
|
| [10] |
PENG Q G, E J, CHEN J W, et al. Investigation on the effects of wall thickness and porous media on the thermal performance of a non-premixed hydrogen fueled cylindrical micro combustor[J]. Energy Conversion and Management,2018,155:276-286. doi: 10.1016/j.enconman.2017.10.095
|
| [11] |
YU Y S, LI Y, LU H F, et al. Performance improvement for chemical absorption of CO2 by global field synergy optimization[J]. International Journal of Greenhouse Gas Control,2011,5(4):649-658. doi: 10.1016/j.ijggc.2011.03.008
|
| [12] |
ZHU Y, XIA C, SHREKA M, et al. Combustion and emission characteristics for a marine low-speed diesel engine with high-pressure SCR system[J]. Environmental Science and Pollution Research,2020,27:12851-12865.
|
| [13] |
CHOI C, SUNG Y, CHOI G M, et al. Numerical analysis of NO x reduction for compact design in marine urea-SCR system[J]. International Journal of Naval Architecture and Ocean Engineering,2015,7(6):1020-1034. doi: 10.1515/ijnaoe-2015-0071
|
| [14] |
ZHU Y Q, ZHANG R P, ZHOU S, et al. Performance optimization of high-pressure SCR system in a marine diesel. part Ⅱ: catalytic reduction and process[J]. Topics in Catalysis,2019,62(1):40-48.
|
| [15] |
TAN L G, GUO Y G, LIU Z, et al. An investigation on the catalytic characteristic of NO x reduction in SCR systems[J]. Journal of the Taiwan Institute of Chemical Engineers,2019,99:53-59. doi: 10.1016/j.jtice.2019.02.020
|
| [16] |
叶杰栋. 船用柴油机SCR系统喷射雾化及催化转化性能研究[D]. 钦州: 北部湾大学, 2021.
|
| [17] |
ZHANG Q L, ZHANG Y Q, ZHANG T X, et al. Influence of preparation methods on iron-tungsten composite catalyst for NH3-SCR of NO: the active sites and reaction mechanism[J]. Applied Surface Science,2020,503:144190. doi: 10.1016/j.apsusc.2019.144190
|
| [18] |
XU H X, LUO J B, PAN Y J, et al. Effect and optimization of radial non-uniform porosity catalyst on SCR characteristics based on response surface method[J]. Journal of Environmental Chemical Engineering,2023,11(5):110771. doi: 10.1016/j.jece.2023.110771
|
| [19] |
马修元, 孙尊强. 燃煤机组电除尘器入口烟道流场优化数值模拟研究[J]. 环境工程技术学报,2023,13(3):965-972. doi: 10.12153/j.issn.1674-991X.20220019
MA X Y, SUN Z Q. Numerical simulation study on flow field optimization of electrostatic precipitator inlet flue duct in coal-fired units[J]. Journal of Environmental Engineering Technology,2023,13(3):965-972. doi: 10.12153/j.issn.1674-991X.20220019
|
| [20] |
赵鸿华, 宋双文, 王志凯, 等. 小弯管冲击冷却结构流场和温度场的场协同分析[J]. 推进技术,2023,44(4):1-7.
ZHAO H H, SONG S W, WANG Z K, et al. Field synergy between flow field and temperature field in concave wall impingement cooling structure[J]. Journal of Propulsion Technology,2023,44(4):1-7.
|
| [21] |
胡娅萍, 吉洪湖. 平壁气膜冷却流场与温度场的协同分析[J]. 工程热物理学报,2004,25(1):94-96. doi: 10.3321/j.issn:0253-231X.2004.01.027
HU Y P, JI H H. Synergetic analysis of velocity and temperature fields of flat plate film cooling[J]. Journal of Engineering Thermophysics,2004,25(1):94-96. doi: 10.3321/j.issn:0253-231X.2004.01.027
|
| [22] |
ZHANG Z Q, YE J D, LV J S, et al. Investigation on the effects of non-uniform porosity catalyst on SCR characteristic based on the field synergy analysis[J]. Journal of Environmental Chemical Engineering,2022,10(1):107056. doi: 10.1016/j.jece.2021.107056
|
| [23] |
LUO J B, XU H X, WANG J, et al. The research on dynamic performance of single channel selective catalytic reduction system with different shapes[J]. Journal of Environmental Chemical Engineering,2022,10(5):108530. □ doi: 10.1016/j.jece.2022.108530
|
Figures(12) / Tables(4)
Copyright © Editorial Department of Journal of Environmental Engineering Technology
Supported by: Beijing Renhe Information Technology Co., Ltd.
DownLoad:
