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和满足政府法规的主要焦点。稀燃/稀释火花点火发动机已被证明可以提高燃料经济性并减少污染物排放，但不利的空气/燃料化学计量比导致更显著的循环间变化，这限制了稀燃和EGR稀释的高效率操作的扩展。优化稀/稀汽油发动机的一个关键部分是改进火花点火和火焰核心发展过程，特别是对于利用强缸内流动来加速燃烧以获得更好效率的发动机。火花引发火焰传播涉及复杂的现象，如等离子体通道拉伸以及在强横流场中的多次重燃。从火花等离子体到可燃气体的能量传递是能够形成稳定的火焰核心从而减少高效稀释汽油发动机的循环间变化的关键因素。由于火花在强湍流条件下的延伸和重燃现象十分复杂，目前的燃烧模型对火花等离子体通道的预测还不够准确。对于汽油发动机的稀燃/稀释运行，由于排气温度较低和排气流中的氧丰度，氮氧化物后处理具有挑战性。因此，低温起燃特性和储氧能力的三效催化剂（TWC）是至关重要的TWC建模稀薄/稀释SI发动机的工业需求。本论文的主要研究内容包括：1）建立一个能较好预测火花延伸和再燃现象的火花点火模型; 2）定量确定火花通道的能量分布和火花-燃气能量传递; 3）研究稀/稀点火发动机三元催化器的低温起燃特性。拟议的研究将利用清洁燃烧发动机实验室（CCEL）在测量和控制资源方面的专业知识和优势，由郑博士在FCA的支持下指导。