针对传统汽油机量调节、节流损失大、热效率低等问题，提出基于氢气/汽油复合喷射及分层EGR的当量比点燃式内燃机质调节方案。采用氢气直喷的复合喷射及分层EGR，形成火花塞附近富氢、燃烧室壁富废气的分层混合气；用废气填充小负荷时燃烧室容积；通过氢气喷射、点火正时、气流运动、EGR控制实现氢气、汽油及废气合理分布；低负荷采用单一氢气缸内直喷，其它负荷采用复合喷射或纯汽油喷射。光学内燃机测试与CFD仿真结合分析混合气缸内分层特性；构建氢气/汽油化学反应动力学机理并与CFD模型耦合，研究内燃机燃烧与排放特性；内燃机测试与仿真结合，研究不同工况氢气喷射、点火正时、气流运动、EGR等对燃烧与排放的影响，研究喷射模式切换时内燃机的瞬态特性，优化内燃机控制参数，实现内燃机质调节。项目预期将实现当量比点燃式内燃机质调节，达到节能减排的目的，为点燃式内燃机质调节及氢气在内燃机中的应用提供新的技术方案及理论基础。

Aiming at the problems of large throttling loss and low thermal efficiency of the traditional gasoline engine adopting the quantity adjustment, a scheme of quality adjustment for spark ignition engine under stoichiometric condition based on hydrogen / gasoline combined injection and stratified EGR is proposed. Adopting the stratified EGR technology and combined injection with hydrogen direct injection, a stratified mixture which hydrogen local enrichment around the spark plug, and exhaust gas enrichment around combustion chamber wall can be formed. The exhaust gas is used to fill the combustion chamber volume at low load. The reasonable distribution of hydrogen, gasoline and exhaust gas will be realized by controlling the hydrogen direct injection, ignition timing, airflow motion, EGR parameters and so on. The injection mode adopts pure hydrogen direct injection under low load, and the combined injection or pure gasoline port injection under other loads. The in-cylinder mixture stratification characteristics will be analyzed by using the optical engine experiments combined with CFD simulation. The chemical reaction kinetic model will be established and coupled with the CFD model to investigate the engine combustion and emission characteristics. By means of engine experiments combined with simulation, the effects of hydrogen direct injection, ignition timing, airflow motion, EGR parameters on engine combustion and emission performances under different operating conditions can be investigated, and the transient characteristics for engine during injection mode switching are studied. Meanwhile the engine control parameters are optimized as well as the quality adjustment of internal combustion engine can be realized. The project is expected to realize the quality adjustment of spark ignition internal combustion engine under stoichiometric condition, and achieve the purpose of energy saving and emission reduction, and provide the new technical scheme and theoretical basis for the quality adjustment of spark ignition engine and the application of hydrogen in internal combustion engine.