重型柴油机低温环境喷雾及蒸发特性研究

The effects of nozzle diameter (0.12~0.32 mm) and ambient temperature (550~850 K) on the spray characteristics of heavy-duty diesel engines were measured visually in a constant volume combustion chamber using the Mie-scattering and shadowgraph methods. The results showed that, different from the light-duty diesel engines, the liquid-phase fuel of the heavy-duty diesel engines with the 0.32 mm nozzle still penetrated continuously and failed to reach a quasi-steady state when the ambient temperature was increased to 750 K at various injection pressures and ambient pressures, or when reaching a quasi-steady state, the penetration distance was too long, leading to spray impingement. With the increase of the ambient temperature, the adhesion amount of liquid spray with the 0.32 mm nozzle decreased. Only when the evaporation of fuel was strong enough at the ambient temperature of 850 K, could the height and radius of impingement spray reach a quasi-steady state.