Sufficiently premixed compression ignition of a gasoline-like fuel using three different nozzles in a diesel engine

Abstract

Fuels that are more resistant to autoignition allow more time for mixing before combustion occurs and help to reduce nitrogen oxides (NO _x ) and smoke in a diesel engine. However, hydrocarbon (HC) and carbon monoxide (CO) emissions are high at low loads because combustion is more likely to take place in lean mixture packets with better mixing caused by longer ignition delays. These problems can be significantly alleviated by managing the mixture strength by changing the injection pressure and the nozzle geometries. A single-cylinder diesel engine is run on a mixture of gasoline and diesel with a research octane number of 91, at different speeds, loads, and exhaust gas recirculation levels using three different nozzles. It is much easier to obtain low NO _x and low smoke emissions with this fuel than with a European diesel fuel using the standard nozzle. Larger injector holes and lower injection pressures help to reduce the HC and CO emissions at low loads and also enable the gasoline-like fuel to run at a higher speed of 4000 r/min at a reasonably high load (indicated mean effective pressure) of 10 bar.