DME/C 重油混合燃料を適用したディーゼルエンジン性能

抄録

Diesel engines have been used as power sources of the propulsion as well as the electric generator for oceangoing vessels.Although they have advantages in the thermal efficiency and the durability compared to other types of internal combustion engines,their exhaust gases contain harmful substances, such as the nitrogen oxide, the sulfur oxide or the particulate matter, which cause the environmental pollutions. Dimethyl Ether (DME) has been paid attention as one of alternative fuels of the diesel engine, since it emits less soot emission compared to the fossil fuels. Thus, various studies have been done that use neat DME as the fuel oil of diesel engines. The aim of this study is to clarify whether liquefied DME mixed with Bunker C (JIS C heavy oil) could improve the engine performance of diesel engine. In the present study, a pressure resistant fuel tank was made to mix liquefied DME and Bunker C, and a direct injection type of diesel engine was used to analyze the combustion characteristics. From the experiments, it is obtained that the ignition delay can be shorten with mixing DME to Bunker C. Also, DME mixed fuel can reduce the incomplete combustion substances, such as the carbon monoxide, the unburnt hydrocarbons and the soot. Moreover, it can diminish the amount of the carbon dioxide emission with DME mixed fuel while keeping almost the same thermal efficiency with neat Bunker C.