Homogeneous Charge Compression Ignition (HCCI) Combustion Engine- A Review

At present, it is highly required from the automobile sector to develop clean technologies with lower fuel consumption for ambient air quality improvement, green house gas reduction and energy security. Furthermore, due to continuously stringent emission legislation and the fast depletion of the primary energy resources, the development of new highly efficient and environment friendly combustion systems becomes of paramount importance and hence research need to be done in this area. One such combustion system is Homogeneous Charge Compression Ignition (HCCI) technology, which has the potential to reduce oxides of nitrogen (NOx) and particulate matter (PM) simultaneously maintaining the thermal efficiency at par with that of conventional diesel engine combustion. However, some issues such as combustion phasing control, controlled auto-ignition, operating range, homogeneous charge preparation, cold start, pressure rise rate and noise and emissions of unburned hydro carbon (UHC), and carbon monoxide (CO) need to be solved for successful operation and therefore commercial application of HCCI engine. Other similar combustion concepts, which can be considered as the extension of HCCI, are Low Temperature Combustion (LTC) and Stratified Charge Compression Ignition (SCCI). This paper reviews all the three advanced combustion concepts along with their merits and demerits.