Development of a Multiple Injection Strategy for Heated Gasoline Compression Ignition (HGCI)

Abstract

<div class="section abstract"><div class="htmlview paragraph">A multiple-injection combustion strategy has been developed for heated gasoline direct injection compression ignition (HGCI). Gasoline was injected into a 0.4L single cylinder engine at a fuel pressure of 300bar. Fuel temperature was increased from 25degC to a temperature of 280degC by means of electric injector heater. This approach has the potential of improving fuel efficiency, reducing harmful CO and UHC as well as particulate emissions, and reducing pressure rise rates. Moreover, the approach has the potential of reducing fuel system cost compared to high pressure (&gt;500bar) gasoline direct injection fuel systems available in the market for GDI SI engines that are used to reduce particulate matter.</div><div class="htmlview paragraph">In this study, a multiple injection strategy was developed using electric heating of the fuel prior to direct fuel injection at engine speed of 1500rpm and load of 12.3bar IMEP. The effect of fuel temperature, fuel pressure and start of injection timing are reported for single injection strategy with impact on smoke and pressure rise rates. Double and Triple injection strategies were developed and utilized to maintain the indicated thermal efficiency and NOx emissions, while improving HC, CO, smoke emissions, as well as reducing pressure rise rates to less than 10bar/deg. The HGCI multiple injection strategy was attempted at higher load of 15bar IMEP to demonstrate the potential for low emissions, and high thermal efficiency, with reasonable pressure rise rates and suggest the strategy is scalable to higher speeds and loads.</div></div>