Search Results

The emissions trade-off and combustion characteristics of a high speed, small-bore, direct injection, single cylinder, diesel engine are investigated at three different load conditions. The experiments covered a wide range of parameters including the injection pressure, exhaust gas recirculation (EGR) rate and swirl ratio (Sw). The effects of each parameter on the ignition delay (ID), apparent rate of energy release (ARER), NOx, Bosch smoke unit (BSU), CO and hydrocarbons are investigated. The results show that the NOx emission dropped continuously with the increase in EGR (up to 55%), but with increasing smoke emission in a classical trade-off relationship. The increase in injection pressure generally reduced smoke with NOx penalty; however, the NOx penalty decreased at higher EGR. There also appears to be an increase in the cool flame intensity at the high EGR rates. Applying swirl at high EGR rate and high injection pressure conditions further reduced smoke emissions.

With the increasing focus on reducing CO2 emissions to combat global warming and climate change, the automotive industry is exploring near zero-emission alternative fuels to replace traditional fossil-based fuels like diesel, gasoline, and CNG. Methanol is a promising alternative fuel that is being evaluated in India due to its easy transportation and storage, as well as its production scalability and availability potential. This study focuses on the retro-fitment solution of M100 (pure methanol) SI port-fuel injection (PFI) mode of combustion. A heavy duty single-cylinder engine test setup was used to assess methanol SI combustion characteristic. Lean operation strategy has been investigated. At lean mixture conditions a significant drop in NOX and CO emissions was achieved. The fuel injection techniques and the impact of exhaust gas recirculation (EGR) on the conventional stoichiometric combustion process is highlighted.