Simulation of effect of boundary parameters on combustion in HCCI engine

Both the SENKIN program of the chemical kinetic package CHEMKIN and the reduced model for n-heptane oxidation have been used to simulate the ignition and combustion process in diesel Homogeneous Charge Compression Ignition(HCCI) engine.The influences of intake temperature,intake pressure and equivalence ratio on HCCI combustion were investigated.The results showed that at constant equivalence ratio,the use of boost pressure can expand the load range of HCCI engine,and keep the NOx emissions little change.When the fuel/air mixture is too lean or too rich,CO emissions increases.Fuel mixture stratification causes the increase of NO emissions.