Experimental Investigation of Soot Accumulation and Regeneration in a Catalyzed Gasoline Particulate Filter Utilizing Particulate Quantification and Gas Speciation Measurements
Experimental Investigation of Soot Accumulation and Regeneration in a Catalyzed Gasoline Particulate Filter Utilizing Particulate Quantification and Gas Speciation Measurements
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DOI：
10.1115/icef2018-9627
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发表时间：
2018-11
期刊：
影响因子：
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通讯作者：
Dhruvang Rathod;S. Onori;Z. Filipi;Mark A. Hoffman
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文献类型：
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作者：
Dhruvang Rathod;S. Onori;Z. Filipi;Mark A. Hoffman
最近对汽油乘用汽车的微粒规定促使人们利用汽油微粒过滤器（GPF）来减轻微粒排放。本研究概述了一个全面的实验方法，检查的基本GPF参数：空间放热温升，颗粒捕集效率，和压力上升与颗粒负荷。在底盘测功机上运行一辆在三元催化剂下游装有底层地板催化涂层GPF的GDI车辆，以收集数据。根据颗粒浓度和粒度分布，开发了加速烟尘累积程序，以加快试验，同时避免被动颗粒再生。使用GPF前后的碳烟浓度来测量碳烟捕集效率和总碳烟累积。在实际驾驶中常见的断油滑行事件被用于启动最坏情况的GPF再生，即由于通过GPF的排气流量有限而产生最大温升的再生。检查在GPF之前和之后同时测量的CO2测量值，以计算在每个再生事件期间燃烧的烟灰量。位于GPF内部的热电偶被实现以获得空间上不同的瞬态温度轨迹，并被分析以获得关于GPF内部的烟尘分布的见解。对于不同的烟灰负载和再生温度，跟踪GPF内的最大放热温度升高，以确保GPF基底和催化洗涂层健康。大多数初始碳烟负载需要多次“燃油切断海岸”再生的所有捕获的颗粒质量的完全碳烟氧化。此外，外部供应的氧气被用来获得完整的GPF再生在一个单一的事件。这种特制的系统在保持恒定GPF温度的同时产生了O2可用性，类似于在车辆运行期间主动控制稀空燃比。排放测量表明，该系统成功地再生了所有的GPF烟灰。然而，由于排气流量和释放的总放热之间的幅度差异，GPF内的热电偶仅记录了最小的放热温度升高，从而使人们相信贫主动再生策略对GPF健康几乎没有威胁。
Recent particulate regulations for gasoline passenger cars have prompted the utilization of Gasoline Particulate Filters (GPF’s) to mitigate particulate emissions. This study overviews a comprehensive experimental methodology for examination of essential GPF parameters: spatial exothermic temperature rise, particulate trapping efficiency, and the pressure rise versus particulate loading. A GDI vehicle equipped with a subfloor catalytically washcoated GPF downstream of the three-way catalyst was operated on a chassis dynamometer for data collection. Accelerated soot accumulation procedures were developed to expedite the testing while avoiding passive particulate regeneration based on both particulate concentration and size distributions. Soot concentrations pre and post GPF were used to measure the soot trapping efficiency and total soot accumulation. Fuel-cut coast events, common in real-world driving, were utilized to initiate worst case GPF regenerations, namely regenerations which produce maximum temperature rise due to the limited exhaust flow through the GPF. CO2 measurements simultaneously measured before and after the GPF were examined to calculate the quantity of soot burned during each regeneration event. Thermocouples located inside the GPF were implemented to obtain the spatially disparate, transient temperature traces and analyzed to obtain insights on the soot distribution inside the GPF. The maximum exothermic temperature rise within the GPF was tracked for different soot loadings and regeneration temperatures to ensure GPF substrate and catalytic washcoat health. Most initial soot loadings required multiple ‘fuel-cut coast’ regenerations for complete soot oxidation of all trapped particulate mass. Additionally, externally supplied oxygen was utilized to obtain complete GPF regeneration in a single event. This purpose built system created O2 availability while maintaining constant GPF temperatures, similar to actively commanding lean A/F ratios during vehicle operation. Emissions measurements indicated that this system successfully regenerated all GPF soot. However, due to magnitude disparity between exhaust flow and total exothermic heat released, the thermocouples inside the GPF recorded only minimal exothermic temperature rises, providing confidence that lean active regeneration strategies pose little threat to GPF health.