Combustion and Exhaust Gas Emissions in a Diesel Engine Dual-Fueled with Natural Gas Injected Directly into the Cylinder

摘要

Combustion and exhaust gas emissions characteristics of natural gas injected into the cylinder of a four-stroke-cycle diesel engine and ignited by pilot injection of liquid diesel fuel have been investigated numerically and experimentally. A 3D-CFD simulation has been conducted to examine the effect of natural gas injection timing on the behavior of natural gas mixture. As a result, the optimum injection timing of natural gas was examined for an engine operating condition, which led to improved THC emissions and thermal efficiency. This can be explained by the fact that the distribution of natural gas at ignition plays an important role in combustion and exhaust gas emissions.