Abstract
Keywords:
LPG, Gaseous injection, liquefied injection, volumetric efficiency, SI engine
Abstract
LPG MPI injection technology for SI engines is very promising to control emissions and enhance performance compared to the conventional mixer type LPG supply system. A gaseous LPG injection system has an edge over the liquefied injection system in terms of durability and cost reduction. However, the volumetric efficiency of the gaseous system needs to be investigated to challenge that of liquefied injection system. In this work, measurements of volumetric efficiency were carried out to investigate the performance of gaseous LPG injection system compared with liquefied injection system. Also, an analysis was performed to better understand the thermodynamic states of both injection systems. When the length of an intake pipe is optimized and injection terminates at the maximum opening of intake valve, The volumetric efficiency with gaseous injection shows little (within experimental error) difference from that of liquefied injection, since the temperature and pressure conditions after injection in an intake pipe do not differ significantly with the both cases. This work concludes that a gaseous LPG injection system shows the performance comparable to the liquefied injection system, and as for the next generation fuel supply system a gaseous LPG injection system is very competitive.