车用稀燃天然气(CNG)发动机的开发研究

Research on Lean Burn CNG Vehicle Engines

采用稀薄燃烧方式,是降低发动机排放和改善经济性的有效手段。在以柴油机为原型机开发的单燃料天然气发动机中,对进气系统和燃烧系统等进行了优化设计,采用了增压中冷、多点顺序喷射、高能直接点火以及综合电控技术,使之达到空燃比的精确控制和高能点火,以实现天然气的稀薄燃烧。同时对研制的样机在稀薄燃烧状态下的性能进行了试验研究,获得了良好的经济性和排放性能。

Lean-burn combustion is an effective way for engine to reduce harmful emissions and improve fuel economy.To fit Lean-burn combusting characteristics for its need of higher accuracy of air/fuel ratio controlling and higher igniting energy,inlet system and combustion system were optimized in the development of a single-fuel CNG engine which was reconstructed from a diesel.Some high techniques were adopted, such as super-charger with mid-cooling, sequential multi-point injection, direct high-energy ignition and integrated electronic control.Characteristics of Lean-burn combusting of this CNG engine were studied experimentally.High performance in fuel economy and emissions was acquired.