Influence of charcoal-diesel slurries characteristics on injection system wear and diesel engine operation

The operation of a diesel engine injection system with slurry from charcoal obtained with recycled wood waste and emulsified with diesel oil was studied. The technical challenges resulting from the slurry flow through the hydraulic injector for different injection pressures, particles average diameter, and engine loads were evaluated. Employing the new type of fuel, the engine successfully ran for about 1 hr in each test, and then it started to exhibit erratic loss of power, the smoke emissions increased drastically while the engine efficiency decreased abruptly. Longer grinding times resulted in higher droplet diameters in sprays (coalescence becoming prevalent) and increased slurry viscosities. To avoid the slurry entering around the needle's stem, channels were machined for pressurized oil into the injector's body. A supplementary pressurized automatic feeding system was constructed with lubricating oil ISOVG32 oil fed in pressure steps from 2-7 MPa. As a result, the stability in operation increased and the recurrence of sticking generally decreased. This is an abstract of a paper presented at the STLE Annual Meeting and Exhibition 2010 (Las Vegas, NV 5/16-20/2010).