论文简介 |
Considering the drawbacks of a diesel/natural gas dual-fuel combustion at low load usually is relative to undesirable natural gas-air-diesel mixture distributions in-cylinder and natural gas supply method and pilot diesel
injection strategy are believed to play a critical role in the process of mixture formation in the cylinder. So an
experimental study has been conducted to explore the effects of natural gas injection timing and split pilot
injection strategy on the combustion performance and emissions characteristics in a diesel/natural gas dual-fuel
engine.
In this study, the effects of natural gas injection timing under a constant split pilot injection strategy and a
varying first pilot injection timing under an optimized natural gas injection timing on combustion performance
and emissions are evaluated. The cylinder pressure, Heat Release Rate (HRR), Pressure Rise Rate (PRR), ignition
delay, flame development duration, CA50 and combustion duration as well as THC, CO, NOx emissions are
analyzed for the purpose.
The experimental results indicated that natural gas injection timing and split injection strategy have a significant influence on the combustion performance and emissions characteristics in the dual-fuel engine. The
natural gas premixed combustion stage can be enhanced with retarded natural gas injection timing. The pilot
diesel combustion stage is weakened under the split injection strategy and the combustion process can be improved by reasonably advanced first pilot injection timing. Moreover, combined variation natural gas injection
timing and split pilot injection strategy is a potential way to optimize the performance of the diesel/natural gas
dual-fuel engine. |