Abstract
Hydrogen has a potential alternative to conventional hydrocarbon fuels, because no carbon dioxides (CO2) is emitted from hydrogen combustion and it is able to make hydrogen by an electrolysis of water as renewable energy resources are used. This study aims to obtain stable auto-ignition and combustion of hydrogen when hydrogen is applied to a direct-injection compression ignition engine. In this study, influences of various ambient conditions such as temperatures, coexistence species etc. on auto-ignition and combustion behaviors of hydrogen jets were investigated with a rapid compression and expansion machine (RCEM). To be able to obtain the stable auto-ignition of hydrogen, in this study, first an ambient temperature in the cylinder of RCEM was raised by adding argon (Ar) gas, which has low specific heat capacity, and secondly the temperature was raised through chemical reactions of a little of di-methyl ether (DME), which was added into intake gas before the start of compression stroke. And effects of intermediates generated during the chemical reactions with DME on auto-ignition of hydrogen jet were also evaluated by both chemical kinetic analysis and experimental investigation.
