Brazil

This experimental study examines the effect of adding a hydrogen-enriched synthetic gaseous mixture (HGM’) on the combustion and fuel conversion efficiency of a singlecylinder research engine (SCRE). The work assesses the viability of using this mixture as a supplemental fuel for flex-fuel engines operating under urban driving cycling conditions. An SCRE the AVL 5405 model was employed operating with ethanol and gasoline as primary fuels through direct injection (DI) and a volumetric compression ratio of 11.5:1. The HGM’ was added in the engine’s intake via fumigation (FS) with volumetric proportions ranging from 5% to 20%. The tests were executed at 1900 rpm and 2500 rpm engine speeds with indicated mean effective pressures (IMEPs) of 3 and 5 bar. When HGM’s 5% v/v was applied at 2500 rpm the mean indicated effective pressure of 3 bar was observed. A decrease of 21% and 16.5% in the ISFC was observed when using gasoline and ethanol as primary fuels respectively. The usage of an HGM’ combined with gasoline or ethanol proved to be a relevant and economically accessible strategy in the improvement of the conversion efficiency of combustion fuels once this gaseous mixture could be obtained through the vapor-catalytic reforming of ethanol giving up the use of turbochargers or lean and ultra-lean burn strategies. These results demonstrated the potential of using HGM’ as an effective alternative to increase the efficiency of flex-fuel engines.