Zhang Bin, Li Xuewei, Zuo Qingsong, Yin Zibin, Zhang Jianping, Chen Wei, Lu Chun, Tan Dongli
College of Mechanical Engineering, Xiangtan University, Xiangtan, 411105, China.
Fujian Province Key Laboratory of Ship and Ocean Engineering, Jimei University, Xiamen, 361021, China.
Environ Sci Pollut Res Int. 2022 Nov;29(51):76890-76906. doi: 10.1007/s11356-022-20519-0. Epub 2022 Jun 7.
In order to study the hydrocarbon combustion in the low-temperature catalytic process of a catalytic gasoline particulate filter (CGPF) during cold start, a mathematical model of the CGPF is established and verified firstly. Then, take T (a temperature when the hydrocarbon conversion rate reaches 50%) as hydrocarbon light-off (LO) temperature; the effects of different exhaust parameters and structural parameters on hydrocarbon light-off performance and reaction rate are investigated based on simulation results. Finally, orthogonal experiment analysis is employed to further obtain the most significant factors and suggested parameter solution. The results show that the hydrocarbon LO performance of the CGPF during cold start is positively correlated with exhaust oxygen concentration, porosity, and filter length, but it is negatively correlated with exhaust flow rate and exhaust water vapor concentration. In addition, the inlet of the channel has a significant HC reaction when the oxygen concentration reaches 2.2%, and porosity mainly influences the front half part of the filter. Moreover, the influence degree relationship of the five factors is oxygen > mass flow > porosity > length > water vapor, and the optimum solution of length, vapor, mass flow, porosity, and oxygen is 150 mm, 12.31%, 0.002 kg/s, 0.55, and 2.2%, respectively. This work offers us great reference value for CGPF performance enhancement and hydrocarbon abatement of a GDI engine.
为了研究催化汽油颗粒过滤器（CGPF）在冷启动低温催化过程中的碳氢化合物燃烧情况，首先建立并验证了CGPF的数学模型。然后，将T（碳氢化合物转化率达到50%时的温度）作为碳氢化合物起燃（LO）温度；基于模拟结果，研究了不同排气参数和结构参数对碳氢化合物起燃性能和反应速率的影响。最后，采用正交试验分析进一步获得最显著因素和建议的参数解决方案。结果表明，CGPF在冷启动时的碳氢化合物LO性能与排气氧浓度、孔隙率和过滤长度呈正相关，但与排气流量和排气水蒸气浓度呈负相关。此外，当氧浓度达到2.2%时，通道入口处有显著的碳氢化合物反应，孔隙率主要影响过滤器的前半部分。而且，五个因素的影响程度关系为氧＞质量流量＞孔隙率＞长度＞水蒸气，长度、水蒸气、质量流量、孔隙率和氧的最佳解决方案分别为150毫米、12.31%、0.002千克/秒、0.55和2.2%。这项工作为提高CGPF性能和减少直喷式发动机碳氢化合物排放提供了重要的参考价值。
