Modeling of Spark Ignition and Aftertreatment Systems for SI Combustion Engines

SI 内燃机火花点火和后处理系统建模

• 批准号: 537431-2018
• 负责人: Zheng, Ming
• 金额: $ 6.8万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=720318
• 关键词: Modeling; Spark; Ignition; Aftertreatment; Systems

Developing engines with better fuel economy has become the main focus for the automotive industry to counter global warming and meet government regulations. Lean/diluted spark ignition engines have been proven to improve fuel economy and reduce pollutant emissions, but the unfavorable air/fuel stoichiometry results in more prominent cycle-to-cycle variation which limits the extension of lean-burn and EGR-diluted high efficiency operations. A critical part to optimize the lean/diluted gasoline engines is to improve the spark ignition and flame kernel development processes, especially for the engines that utilize strong cylinder flow to accelerate the combustion for better efficiency. Spark initiated flame propagation involves complex phenomena such as plasma channel stretching as well as multiple restrikes in a strong cross flow field. Energy transfer from the spark plasma to the combustible gas is a key factor to enable stable flame kernel formation thereby reducing the cycle-to-cycle variation of high efficiency diluted gasoline engines. Currently, there is still a lack of accuracy in combustion modeling to predict the spark plasma channel because of the complex phenomenon of spark stretching and restrike under strong turbulent flow. As for the lean/diluted operation of gasoline engines, the nitrogen oxides aftertreatment is challenging due to the lower exhaust temperature and the oxygen abundance in the exhaust stream. Thus, the low temperature light-off characteristics and oxygen storage capability of the three-way-catalyst (TWC) are of critical importance in TWC modeling for lean/diluted SI engines for industrial needs. The proposed research will focus on: 1) building an empirical spark ignition model which can better predict the spark stretching and the restrike phenomenon; 2) quantitatively determining the energy distribution of the spark channel and the spark-to-gas energy transfer; 3) investigating the low temperature light-off of TWC for lean/diluted SI engines. The proposed research will utilize the established expertise and advantages in measurement and control resources at the Clean Combustion Engine Laboratory (CCEL), directed by Dr. Zheng with supports from FCA.

开发具有更好燃油经济性的发动机已成为汽车行业应对全球变暖并符合政府法规的主要重点。已被证明精益/稀释的火花点火发动机可以改善燃油经济性并减少污染物的排放，但是不利的空气/燃料化学计量计量会导致更为突出的周期到周期变化，从而限制了瘦肉燃烧和Egr二式高效率操作的扩展。优化精益/稀释的汽油发动机的关键部分是改善火花点火和火焰内核开发过程，尤其是对于利用强缸流量来加速燃烧以提高效率的发动机。火花引发的火焰传播涉及复杂的现象，例如等离子体通道拉伸以及强烈的跨流场中的多个限制。从火花等离子体到可燃气体的能量转移是实现稳定的火焰内核形成的关键因素，从而减少了高效率稀释的汽油发动机的循环到周期变化。当前，由于在强湍流下，火花拉伸和约束的复杂现象，仍然缺乏燃烧建模的准确性来预测火花等离子体通道。至于汽油发动机的精益/稀释操作，由于排气温度较低和排气流中的氧气丰度，治疗后的氮氧化物是具有挑战性的。因此，三向催化剂（TWC）的低温轻开关特性和氧气存储能力在TWC建模中对于用于工业需求的精益/稀释SI发动机至关重要。拟议的研究将重点放在：1）建立经验的火花点火模型，该模型可以更好地预测火花拉伸和约束现象； 2）定量确定火花通道的能量分布和火花向气体的能量传递； 3）研究瘦/稀释的SI发动机TWC的低温灯光。拟议的研究将利用Zheng博士在FCA的支持下执导的清洁燃烧发动机实验室（CCEL）的测量和控制资源的既定专业知识和优势。