Improvement of Exhaust Gas Emission in Marine Diesel Engine by Blending DME 2007-01-2014

Diesel engine has been used as a power source in many fields, because of its high thermal efficiency and durability. But its exhaust gas emissions, such as NOx or Particulate Matter, are considered as the matter which brought the air pollution. Thus, it is needed to reduce such harmful matters to agree with the level set by the legislation.

In this study, the engine performance of the mixed fuel comprised of DME (Dimethyl Ether) and marine diesel oil was experimentally examined. Because of the molecule properties of DME, it emits no soot in combustion. At the atmospheric condition, DME can be liquefied with rising in its pressure. When liquefied DME is injected in combustion chambers, the flashing energy is supposed to be useful as the atomization of other liquid fuels. A small high-speed direct injection diesel engine was used as the test engine. Its bore and stroke were 92mm and 96mm, and the compression ratio was 17.7. The fuel pump was jerk type and was utilized without major modifications. The engine was operated at 4 different speeds with variation in the engine load.

From experiments, the ignition delay becomes shorter with increase with the mixing ratio of DME. The smoke emissions were reduced for every engine load condition with mixing DME. From experimental results, it is concluded that DME is useful for reducing in the smoke emission in the diesel engine combustion.