Designing Anti-crystallization Short Pitch Spiral Hybrid Structure of Diesel Engine
-
摘要: 以尿素为还原剂的选择性催化还原技术在处理柴油机尾气中的氮氧化物有较好的应用，但结晶问题始终存在。为有效解决尿素结晶问题，设计了一款新型短距螺旋混合结构。首先通过仿真来对新旧混合器结构的尿素分解能力和抗结晶性能进行分析。其次，进一步对新型混合器结构的结晶性能进行实验验证。结果表明新型混合结构能有效提高抗结晶性能，同时还具有较高的无结晶风险尿素临界喷射量。Abstract: The selective catalytic reduction technology that uses urea as reduction agent is well applied to the treatment of nitrogen oxides in the exhaust of a diesel engine, but the urea crystallization problem always exists. In order to effectively solve the crystallization problem, a new short-pitch spiral hybrid structure was designed. Firstly, the urea decomposition capacity and anti-crystallization performance of the old and new mixers were analyzed through simulation. The crystallization performance of the new mixer′s structure was further verified through experiments. The results show that the new hybrid structure can effectively improve the anti-crystallization performance and has a higher critical urea injection capacity without crystallization risk. The purpose of this study is to improve the crystallization performance by optimizing the mixer′s structural design.
-
Key words:
- selective catalytic reduction /
- hybrid structure /
- urea injection
-
表 1 仿真研究工况边界条件
工况 转速/(r·min-1) 扭矩/(N·m) 温度/℃ 排气流量/(kg·h-1) 氮氧化物/ppm 尿素喷量/(mg·s-1) 1 1 480 380 503 231 550 118.4 2 3 000 350 550 505 473 222.5 3 1 480 80 250 95 250 22.1 4 3 000 30 250 190 100 17.7 
下载: 导出CSV
表 2 实测结晶工况边界条件
工况 转速/(r·min-1) 扭矩/(N·m) 温度/℃ 排气流量(kg·h-1) 氮氧化物/ppm 尿素喷量/(mg·s-1) 尿素/排气 1 1 400 66 188 92 260 26 1.0 2 1 700 101 245 129 213 71 2.0 3 1 700 140 288 152 249 83 2.0 4 1 700 140 284 152 249 123 2.9 5 1 750 101 245 134 211 35 1.0 6 2 300 250 357 322 304 222 2.5 7 2 300 355 405 413 452 388 3.4 8 2 800 68 215 242 118 66 1.0
下载: 导出CSV
表 3 尿素液滴蒸发效果
表 4 液膜厚度表
-
[1] 暴辰生, 朱丽, 张益铮, 等. 高效净化柴油机尾气污染的工艺方法探索[J]. 内燃机, 2016(3): 13-16 https://www.cnki.com.cn/Article/CJFDTOTAL-NRJJ201603004.htmBAO C S, ZHU L, ZHANG Y Z, et al. Explore method for efficient treatment diesel exhaust[J]. Internal Combustion Engines, 2016(3): 13-16 (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-NRJJ201603004.htm [2] LECOMPTE M, OBIOLS J, CHEREL J, et al. The Benefits of Diesel Exhaust Fluid(DEF) additivation on urea-derived deposits formation in a close-coupled diesel SCR on filter exhaust line[J]. SAE International Journal of Fuels and Lubricants, 2017, 10(3): 864-876 http://www.onacademic.com/detail/journal_1000040548631510_6c7b.html [3] CAPETILLO A J, IBARRA F, STEPNIEWSKI D, et al. Multiphase modelling of SCR systems: using the taguchi method for mixer optimisation[J]. SAE International Journal of Engines, 2017, 10(1): 61-71 doi: 10.4271/2017-26-0113 [4] 江涛, 范皖元, 宋长青. 后处理结构对柴油车尿素结晶的影响[J]. 汽车工程学报, 2019, 9(3): 221-226 https://www.cnki.com.cn/Article/CJFDTOTAL-QCYK201903009.htmJIANG T, FAN W Y, SONG C Q. Research on urea crystallization optimization for diesel SCR systems[J]. Chinese Journal of Automotive Engineering, 2019, 9(3): 221-226 (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-QCYK201903009.htm [5] 臧志成, 魏家星, 卢凯, 等. 喷嘴集成式SCR混合器设计与数值模拟研究[J]. 内燃机工程, 2017, 38(4): 103-108 https://www.cnki.com.cn/Article/CJFDTOTAL-NRJG201704017.htmZANG Z C, WEI J X, LU K, et al. Design of and numerical simulation study on injector integrated SCR mixer[J]. Chinese Internal Combustion Engine Engineering, 2017, 38(4): 103-108 (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-NRJG201704017.htm [6] 韩峰, 张晓丽, 王意宝, 等. 逆流式混合器的设计及尿素结晶风险评估方法研究[J]. 汽车工程, 2019, 41(12): 1370-1376, 1383 https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC201912004.htmHAN F, ZHANG X L, WANG Y B, et al. Study on counterflow mixer design and urea crystallization risk assessment method[J]. Automotive Engineering, 2019, 41(12): 1370-1376, 1383(in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC201912004.htm [7] CHOI C, SUNG Y, CHOI G M, et al. Numerical analysis of NOx 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 [8] 刘军, 王明远, 周磊, 等. 基于优化尿素液滴蒸发特性的SCR混合器[J]. 内燃机学报, 2018, 36(4): 332-337 https://www.cnki.com.cn/Article/CJFDTOTAL-NRJX201804006.htmLIU J, WANG M Y, ZHOU L, et al. SCR mixer based on an optimization of urea droplet evaporation[J]. Transactions of CSICE, 2018, 36(4): 332-337(in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-NRJX201804006.htm [9] ZHANG C F, SUN C, WU M P, et al. Optimisation design of SCR mixer for improving deposit performance at low temperatures[J]. Fuel, 2019, 237: 465-474 http://www.sciencedirect.com/science/article/pii/S0016236118317393 [10] LEE C. Numerical and experimental investigation of evaporation and mixture uniformity of urea-water solution in selective catalytic reduction system[J]. Transportation Research Part D: Transport and Environment, 2018, 60: 210-224 http://www.sciencedirect.com/science/article/pii/S1361920917303255 [11] 钱枫, 吕林, 杨栋. 柴油机SCR系统排气管壁沉积物影响因素仿真[J]. 内燃机学报, 2018, 36(2): 144-152 https://www.cnki.com.cn/Article/CJFDTOTAL-NRJX201802007.htmQIAN F, LV L, YANG D. Simulation of deposit formation inside the exhaust pipe on a diesel engine with SCR[J]. Transactions of Csice, 2018, 36(2): 144-152(in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-NRJX201802007.htm [12] 唐韬, 赵彦光, 华伦, 等. 柴油机SCR系统尿素水溶液喷雾分解的试验研究[J]. 内燃机工程, 2015, 36(1): 1-5 https://www.cnki.com.cn/Article/CJFDTOTAL-NRJG201501001.htmTANG T, ZHAO Y G, HUA L, et al. Experimental study of urea solution spray and decomposition of SCR system for diesel engine[J]. Chinese Internal Combustion Engine Engineering, 2015, 36(1): 1-5 (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-NRJG201501001.htm [13] LIAO Y J, EGGENSCHWILER P D, FURRER R, et al. Heat transfer characteristics of urea-water spray impingement on hot surfaces[J] International Journal of Heat and Mass Transfer, 2018, 117: 447-457 http://www.onacademic.com/detail/journal_1000040098101310_81c4.html [14] 张扬, 朱志宇. 船舶柴油机SCR系统尿素喷射控制仿真[J]. 船舶工程, 2019, 41(12): 14-20 https://www.cnki.com.cn/Article/CJFDTOTAL-CANB201912006.htmZHANG Y, ZHU Z Y. Simulation of urea injection control for SCR system of marine diesel engine[J]. Ship Engineering, 2019, 41(12): 14-20 (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-CANB201912006.htm [15] 岳广照, 刘兴华, 孙柏刚, 等. 柴油机SCR尿素喷射方式研究[J]. 北京理工大学学报, 2018, 38(2): 143-149 https://www.cnki.com.cn/Article/CJFDTOTAL-BJLG201802006.htmYUE G Z, LIU X H, SUN B G, et al. Research on SCR urea injection method of diesel engine[J]. Transactions of Beijing Institute of Technology, 2018, 38(2): 143-149 https://www.cnki.com.cn/Article/CJFDTOTAL-BJLG201802006.htm -
点击查看大图
图(7) / 表(4)
计量
- 文章访问数: 121
- HTML全文浏览量: 43
- PDF下载量: 18
- 被引次数: 0
