Computational study on the ignition timing of HCCI combustion in IC engines fuelled with methane

Engines with Homogeneous Charge Compression Ignition (HCCI) combustion offer a number of benefits over conventional SI and CI combustions, such as low NOx emission, negligible cycle-to-cycle variation, higher combustion efficiency at part load than SI counterpart at part load, and low soot emission. Unlike SI and CI engines, where combustion is directly controlled by the engine management system, the combustion in HCCI engines is controlled by chemical kinetics only. Sophisticated strategies for ignition timing and rate of heat release control over wide engine operation range need to be developed. Using SENKIN chemical kinetics simulation package developed by Sandia, the effect of a number of engine operation parameters on the ignition timing of HCCI combustion has been calculated. Results were analysed and reported in this paper. It has been found that a high inlet temperature can be used to initiate the HCCI combustion, but EGR and air/fuel ratio appears to be the potential practical methods for ignition timing and engine load control.