Effects of co‐combustion ratio on rapid combustion, cyclical variation, and emissions of a heavy‐duty diesel engine fueled with diesel‐methanol dual‐fuel

Abstract

Diesel-methanol dual-fuel (DMDF) combustion was achieved on a 6-cylinder, heavy-duty, turbocharged and common-rail diesel engine. In DMDF mode, the coalproduced methanol is induced to the upstream of the intake manifold and premixed with the fresh air to form a homogeneous methanol-air mixture and then ignited by directinjected pilot diesel in cylinder. The purpose of this study is to investigate the effects of co-combustion ratio (CCR) on the rapid combustion, cyclical variation and emissions of the DMDF engine. The experimental results show that CCR affect the rapid combustion (a) and knock tendency (b) greatly. With CCR increasing, both a and b increase significantly. The b exhibits an obviously large value under heavy load although CCR and a are small. At larger CCR, DMDF mode may generate a seriously cyclical variation and the coefficient of variation for indicated mean effective pressure (COV IMEP ) exhibits a relatively large value. However, with engine load increasing, the cyclical variation can be obviously decreased. It is also shown that both NOx and smoke emissions in DMDF mode present an obviously decrease trend, while CO and HC emissions exhibits an increase trend. A further reduction of NOx and smoke emissions can be obtained by increasing CCR, but CO and HC emissions are increased in this case.

Effects of Different Mixture Ratios of Methanol-Diesel on the Performance Enhancement and Emission Reduction for a Diesel Engine

“…This is because the high oxygen content of methanol itself can alleviate the local oxygen deficiency in diesel engines during diffusion combustion. In addition, the micro-explosion phenomenon occurs in methanol-diesel fuel mixtures [45]. The larger the ratio of methanol, the more pronounced the micro-explosion phenomenon is, which improves the overall combustion phenomenon and compensates for the reducing calorific value.…”

Metal‐based additives “acetylferrocene and ruthenium polypyridyl complex” to improve performance and emission characteristics of ci engine

“…Diesel engines have widely uses in many sectors such as transport, energy generation, and agriculture since they offer prominent characteristics (low fuel consumption, high durability, reliability, etc.) . It is estimated that diesel engines will have been one of the dominant energy sources in the near future .…”