Influences of Combustion Boundary Conditions on Ethanol Homogeneous Charge Compression Ignition Combustion

The influences of combustion boundary conditions on ethanol homogeneous charge compression ignition(HCCI)combustion were investigated.The experiments were carried out on a modified CA6110 engine.For the fixed engine speed and intake temperature,with the increase of air/fuel equivalence ratio, the initial point of combustion postpones,the combustion duration increases,the maximum cylinder pres- sure increases and the combustion efficiency decreases.While with the increase of EGR ratio,the same behaviors are presented in combustion parameters.For fixed engine speed and fuel supplying amount,with the increase of intake temperature,the phasing of combustion occurs earlier,combustion duration decrea- ses,the rate of pressure rise increases and the maximum cylinder pressure increases.The MAP of the en- gine speed,air/fuel equivalence ratio and intake temperature for achieving maximum indicated thermal ef- ficiency is obtained.