ID 373

Effects of injector nozzle hole number and hydraulic flow rate on combustion and emission characteristics in a heavy duty diesel engine

 

Abstract:

This study investigated the influence of the injector nozzle hole number and HFR on combustion and emission characteristics in a 1.1L single cylinder diesel engine equipped with a direct injection system. In addition, the spray development processes were visualized at a constant volume chamber by using a high speed camera. The test injectors of the present study have various hole numbers from 6 to 12. In addition, effects of hydraulic flow rate (i.e., 108cc/min and 163cc/min) on spray development and engine performances were investigated at fixed hole number of 8. Results showed that particulate emissions emitted from the engine were reduced as the number of injector nozzle holes increased. This is a result of the advantage of the mixture formation because the nozzle holes diameter is reduced and droplets of smaller size are injected as the number of nozzle holes increases. However, NOx emissions, which is a trade-off relationship with PM, tends to increase as the number of holes increases. This is because the initial droplet is decreased and the mixture formation is advantageous.