Technical Paper
Experiments and Multi-Dimensional Simulation of Dual-Fuel Diesel/Natural Gas Engines
2007-09-16
2007-24-0124
Dual-fuel engines, based on the use of natural gas (NG) as the main fuel in internal combustion engines (ICE) and using diesel injection as the ignition source instead of the spark plug, are one of the possible ways to reduce the trade off PM-NOX problem of traditional diesel engines. The high octane number (NOR) of NG allows to easily covert existing diesel engine, without varying the original compression ratio, with great advantages in terms of costs. The only modifications concern with the introduction of feeding system for NG and the reduction of diesel quantity injected into the combustion chamber, by acting on injection pump control. For high degrees of substitution, diesel oil can be considered only as the ignition source for the fresh air/NG mixture, with consequent beneficial effects on PM emissions. The real drawback regarding dual-fuel engines is the wide increase in HC and CO emissions and efficiency worsening, especially under part-load conditions.