A computational study into the effect of exhaust gas recycling on homogeneous charge compression ignition combustion in internal combustion engines fuelled with methane

Abstract

Engine with homogeneous charge compression ignition, HCCI, combustion offers a number of benefits over conventional SI and CI, such as much lower NO x emission, negligible cycle-to-cycle variation, higher combustion efficiency at part load than its SI counterpart, and low soot emissions. Unlike conventional SI and CI engines, where the combustion is directly controlled by the engine management system, the combustion in HCCI engines is controlled by its chemical kinetics only. Trapping hot internal EGR appears to be a potential technology for a practical application of this potential technology. In this paper, by using the advanced combustion simulation package SENKIN, both thermal and chemical effects of the hot EGR on HCCI combustion were calculated and analysed. It was found that the thermal energy contained in the EGR is essential for the combustion initiation, but the chemical species it contained have different effects towards both combustion ignition timing and heat release rate.