Abstract
In order to clarify misfire and knock limits of HCCI combustion in a multi-cylinder engine fueled with DME/Natural-gas, exhaust gas temperatures and cylinder liner temperatures at the top ring position were measured in each cylinder of a four-cylindered engine, comparing with a single cylinder engine. It is found that the liner temperature and the exhaust gas temperature become lower at the cylinders of No.1 and 4 than No.2 and 3 near the misfire limit condition due to intermittent occurrence of misfire in the end cylinders of No.1 and 4, which seems to be caused by the cooling system of a multi-cylinder engine. The minimum DME amount for obtaining stable ignition is larger in the multi-cylinder engine than the single cylinder one.
