Combustion engine and method of use resulting in reduced soot emissions

摘要

Since combustion engines may emit soot it may be necessary to eliminate soot from combustion engine emissions in order to comply with regulatory requirements. Where it is desirable to avoid the need for a separate after-treatment apparatus in order to eliminate soot from combustion engine emissions a compression ignition engine, comprising a combustion cylinder with an injector 12b to inject fuel into the cylinder, may be configured to result in combustion having a peak value of equivalence ratio at the lift off length 30b of less than 4.0, and preferably less than 2.0, such that combustion results in particulate emissions of fewer than 1012 particles per kWh. The engine may operate with a fuel injection pressure of between 240 and 300 MPa, and the temperature of the unburnt gases within the cylinder may be configured to be less than 880 k.