Ignition Criterion Studies on Lean and Diluted Mixtures for Clean Combustion in Automotive Engines

汽车发动机清洁燃烧稀混合气和稀释混合气的点火准则研究

• 批准号: RGPIN-2018-04004
• 负责人: Zheng, Ming
• 金额: $ 3.35万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712308
• 关键词: Ignition; Criterion; Studies; Lean; Diluted

Worldwide efforts with cutting-edge technologies are making significant progresses to improve the understanding, therefore the design and control of clean combustion engines. The lean and diluted fuel-air mixtures are effective to improve the efficiency and emissions of spark ignition (SI) engines, but are more difficult to ignite than a stoichiometric and homogeneous mixture. Traditionally, gasoline is injected during intake stroke, either at an intake port or directly into a cylinder. The cylinder charge usually reaches full homogeneity at the end of cylinder compression. Thereon, providing the air/fuel ratio (AFR) is stoichiometric, spark ignition succeeds with little difficulty, even with limited spark energy and duration. However, the burning efficiency of a stoichiometric cylinder charge is insufficient, and usually 6~8% of injected fuel skips combustion. An overall lean mixture can improve the burning efficiency, and reduces the reliance on intake throttling under partial loads. The use of exhaust gas recirculation (EGR) also reduces the pumping loss, while lowing the flame temperature and the nitrogen oxides (NOx) formation. When operating with lean and diluted mixtures, an engine needs to boost the intake air to retain full power. In synergy with automotive downsize and hybridization, the intake boost is also necessary for a small engine to produce more power at a higher efficiency. The proposed research establishes a strategy to study the criteria of ignition. Optically-accessible combustion cells will be used to study the ignition criteria of premixed mixtures, with precisely-controlled AFR, temperature, pressure, and dilution. Single cylinder research engines will be used to study the impact of in-cylinder flow and homogeneity, under independently-controlled fuel injection, intake boost, and EGR. Volatile fuels, including gasoline, ethanol, methane, and propane, will be injected at the intake port or directly into the cylinder, in single or multiple injection events. The spark and corona ignition with controls on the ignition energy, duration, events, sites, and volume will be investigated. The results of this research will provide guidelines for improving the fuel efficiency of SI engine clean combustion, specifically to the forming of a locally-ignitable mixture that encapsulates the gap of a sparkplug in transience to succeed the flame kernel formation and combustion. This research provides an ideal scenario for training HQP.

在全球范围内，尖端技术的努力正在取得重大进展，以改善理解，因此设计和控制清洁燃烧引擎。稀释和稀释的燃油空气混合物可有效提高火花点火（SI）发动机的效率和排放，但比化学计量和均匀的混合物更难点燃。传统上，在进气端口或直接进入圆柱体的过程中，在进气中心注射汽油。气缸电荷通常在气缸压缩结束时达到完全均匀性。因此，提供空气/燃料比（AFR）是化学计量的，即使火花能量和持续时间有限，Spark Ignition也很难成功。但是，化学计量缸电荷的燃烧效率不足，通常6〜8％的注射燃油跳过燃烧。整体瘦肉混合物可以提高燃烧效率，并减少部分载荷下的进气门的依赖。使用废气再循环（EGR）还减少了泵的损失，同时降低火焰温度和氮氧化物（NOX）形成。当使用瘦弱和稀释的混合物运行时，发动机需要增强进气空气以保持全功率。在与汽车缩小和杂交的协同作用下，小型发动机以更高的效率产生更大的功率也是必要的。 拟议的研究制定了一项策略来研究点火标准。光学上可访问的燃烧细胞将用于研究预混合混合物的点火标准，并具有精确控制的AFR，温度，压力和稀释。单缸研究引擎将用于研究独立控制的燃油注入，进气增强和EGR的缸内流量和均匀性的影响。在单个或多个注射事件中，将在进气口或直接注入包括汽油，乙醇，甲烷和丙烷在内的挥发性燃料。火花和电晕点火带有对点火能量，持续时间，事件，地点和体积的控制。 这项研究的结果将为提高SI发动机清洁燃烧的燃油效率提供指南，特别是形成了当地可疑的混合物，该混合物封装了火花弹性的差距，以成功地将火焰内核形成和燃烧成功。这项研究为培训HQP提供了理想的方案。