米勒循环汽油机燃用氢气燃烧及排放特性分析OA北大核心CSTPCD

The high-pressure Miller-cycle direct gasoline injection engine was installed with a hydrogen injection engine.The combustion and emission differences between the engine's use of gasoline and hydrogen were experimentally studied.We used an electronic compressor to explore the thermal efficiency of the ultra-rarefied combustion of the hydrogen injection engine in its lean burn mode.The effects of a three-way catalytic(TWC)converter on the conversion efficiency of nitrogen oxide and NH3 were analyzed.The results show that the hydrogen engine is sensitive to engine knock under large load condition.Lean combustion can further improve the thermal efficiency.At the speed of 2 500 r/min,when PBME=0.8 MPa and the excess air coefficient increases from 1.0 to 3.0,the thermal efficiency increases by 30%and the NOx emission decreases by about 98%.When the load further increases to PBME=1.1 MPa,the thermal efficiency exceeds 43.0%.The NOx conversion efficiency of the traditional gasoline engine TWC for hydrogen engine is relatively high under rich content condition.A large amount of ammonia may be generated after TWC conversion.When the mixture is further diluted,the amount of NH3 generation decreases significantly.