DME 예혼합 압축착화 엔진에서 수소의 영향

Abstract

Homogeneous charge compression ignition combustion (HCCI) is an advanced combustion technology that makes higher thermal efficiency and lower NOx emissions than that of conventional combustion system. Dimethyl ether (DME) which has been researched for the most attractive alternative fuel of diesel is more suitable for HCCI combustion because of the higher evaporation property. In this study, The single cylinder DME engine operated with a direct injection spark ignition (DISI) injection system has been made to investigate combustion processes and emissions of DME HCCI and to find the effects of premixed hydrogen in internal combustion. The experiment was carried by varying the engine speed and fraction rates of hydrogen. The dual fuel is mixed at the early time with changing the proportion. As a result, the increase of fraction rates of hydrogen had the effect to retard the DME ignition timing and to eliminate the knocking effect during high load condition. IMEP was increased until 30% fraction rates of hydrogen. There was almost misfiring that the fraction rates of hydrogen is more than 40%. NOx emission was reduced by increasing the fraction rates of hydrogen, but HC emission was increased.