Experimental study on wide load operation of gasoline compression ignition engine: Real distillate gasoline versus primary reference fuel

This paper aims to achieve high efficiency, low emissions and stable gasoline compression ignition (GCI) combustion over a wide range of engine loads. The real distillate gasoline fuels with research octane number (RON) of 83 and 72, denoted as G80 and G70, were applied to investigate the GCI combustion and emissions. To break through the limitation of injection pressure on engine load, the port injection combined with direct injection (PIDI) mode was studied for indicated mean effective pressure (IMEP) from 10 bar to 13 bar. The combustion and emission characteristics of primary reference fuels (PRF) with RON of 80 and 70 were also tested for comparison. The results indicate that high net indicated thermal efficiency (ITEnet) are obtained in a wide range of engine loads for GCI modes, especially the ITEnet of G70 is up to 51%. Compared with the PRFs, the low-RON gasoline fuels possess lower fuel consumption as well as lower THC and CO emissions, but higher NOx emissions. The low-RON gasoline fuels also produce more particle emissions than the PRFs under medium-high loads. Compared with DI mode, the PRRmax, particle emissions are improved in PIDI mode. However, the ITEnet, CO and THC emissions are deteriorated.