Analysis of Supercharged HCCI Combustion Using Low-Carbon Alternative Fuels

This study investigated the effects of recirculated exhaust gas (EGR) and its principal components of N₂, CO₂ and H₂O on moderating Homogeneous Charge Compression Ignition (HCCI) combustion. Experiments were conducted using two types of gaseous fuel blends of DME/propane and DME/methane as the test fuels. The addition rates of EGR, N₂, CO₂ and H₂O were varied and the effects of each condition on HCCI combustion of propane and methane were investigated. The results revealed that the addition of CO₂ and H₂O had the effect of substantially delaying and moderating rapid combustion. The addition of N₂ showed only a slight delaying and moderating effect. The addition of EGR had the effect of optimally delaying the combustion timing, while either maintaining or increasing the indicated mean effective pressure and indicated thermal efficiency ηi.