进气压力对柴油微引燃乙醇发动机的影响

基于单缸四冲程柴油机,对在船舶上具有应用前景的柴油微引燃乙醇发动机进行燃烧、性能及排放特性研究。以所采用发动机中能实现压燃着火的最小柴油量为固定引燃柴油喷射量,比较进气压力分别为0.15 MPa和0.20 MPa的工况组,通过改变柴油喷射时刻来进行工况扫描。结果显示:进气压力更大的工况,着火滞燃期更短,燃烧持续期更长,指示热效率更低;存在两阶段着火的工况点,第一阶段放热的占比更大;进气压力增大时,氮氧化物(NOX)排放更低,但未燃碳氢(UHC)与一氧化碳(CO)排放更高。

Influence of Intake Pressure on Diesel Micro Ignition Ethanol Engine

Based on a single-cylinder four-stroke compression ignition engine, the engine performance and emission characters of the diesel micro ignition ethanol engine onboard with application prospects are studied. With pilot diesel amount fixed to the minimum mass to realize compression-ignition in the engine used in the study, two sets of working conditions with different intake air pressure of 0.15 MPa and 0.20 MPa are compared. The condition scan is carried out by changing the diesel injection time. The result shows that higher intake air pressure brings shorter ignition delay, longer combustion duration and lower IMEP. If there is the condition point of two-stage ignition, there is stronger first-stage heat release. When the intake air pressure increases, it causes lower emission of NOX, but higher emission of UHC (unburnt hydrocarbon) and CO (carbon monoxide).