Application to Diesel Engine of Mixed Fuel Comprising DME and A-Heavy Oil (Marine Diesel Engine Oil)

Abstract

In previous paper, we improved the diesel engine system to use DME (Di-Methyl Ether) as fuel oil. The engine performance using the mixed fuel comprised of DME and Marine diesel oil was reported. In this report, further investigation was carried out in varying mixing ratio of DME and Marine diesel oil. In the experiments, combustion pressure, rate of heat release, pollutant emissions and injection condition were measured using a small high-speed single-acting 4 stroke diesel engine. A high-speed video camera was used to investigate the fuel spray pattern. As a result, it is shown that the ignition delay becomes shorter by increasing the mixing ratio of DME to Marine diesel oil. Fuel spray spreads wider in radial direction in case of higher mixing ratio of DME. Due to the changes in combustion history and spray pattern, concentration of soot and CO emission become smaller by increasing the mixing ratio of DME to Marine diesel oil.