针对起重机专用发动机在低转速工况下工作时soot排放高和再生里程短等问题，通过试验与化学动力学结合，研究了不同流量喷油器对发动机性能和soot排放的影响，探明了PAHs的生成路径。结果显示，与大流量喷油器相比，发动机采用小流量喷油器后，缸内压力峰值和瞬时放热率峰值降低，燃烧持续期延长，释放的大量热量使得A₂，A₂—，A₃，A₃—和A₂R₅等PAHs关键中间产物减少，soot排放下降。此外，采用小流量喷油器不仅对发动机性能影响较小，还可极大降低soot排放。在起重机运行工况范围内，当采用小流量喷油器时，随着运行扭矩增加，喷油正时延迟结合较小的喷油压力，可使发动机实现高热效率和低soot排放，这有利于提高发动机的经济性和减少因积碳过多导致的成本增加。

To address issues such as high soot emissions and short regeneration intervals in crane-specific engines operating at low speed, experiment was combined with chemical kinetics to investigate the effects of different-flow-rate injectors on engine performance and soot emissions, and the formation pathways of PAHs were identified. The results show that the low-flow injectors reduce peak cylinder pressure and peak instantaneous heat release rate and prolong the combustion duration compared to the large-flow fuel injectors. The release of a large amount of heat reduces key PAHs intermediates such as A₂，A₂—，A₃，A₃—and A₂R₅, thereby lowering soot emissions. Additionally, the adoption of low-flow injector not only has a minimal impact on engine performance but also significantly reduces the emissions of soot. Within the operating conditions of cranes, when a low-flow injector is used, as the operating torque increases, the combination of delayed injection timing and lower injection pressure enables the engine to achieve high thermal efficiency and low soot emissions. This is beneficial for enhancing engine fuel economy and reducing costs associated with excessive carbon deposition.