Characteristics of vibration and noise in high speed diesel engine using emulsified fuel

摘要

In general when water emulsified fuel is used in diesel engines, burning speed is enhanced and vibration/noise is increased. Experimental results showed that noise in the range of high frequency increases rapidly due to the vibration resonance of engine parts and stronger pressure oscillation with increasing of a water addition amount of emulsified fuel. Especially, stronger combustion noise was caused in the range of 1.2kHz due to engine structure vibration resonance for the engine. But noise in the range of lower frequency slightly rises. The experimental results shown also that NO{sub}x Emission can be reduced and combustion can be controlled, and good economy still be keep if the burning start is properly delayed. For the experimental engine, when injection timing was 6deg retarded from the original and 30% water emulsified fuel was used, NO{sub}x emission was reduced by 60% without bad fuel economy and noise increasing compared with normal injection timing and using pure fuel.