PCCI Investigation Using Variable Intake Valve Closing in a Heavy Duty Diesel Engine

1. PCCI Investigation Using Variable Intake Valve Closing in a Heavy Duty Diesel Engine Experimental Setup Boost Increase Intake Pressures (kPa) Tested Ryan Nevin, Professor Rolf Reitz and Manuel GonzalezFunding Sponsors: Caterpillar and US Department Of Energy Solenoid Driven IVA System Baseline IVC Sweep Valve Lift Curves • NOx decreases with lower in-cylinder temperatures, while PM increases due to less available oxygen to oxidize soot • Late IVC (i.e. 60°BTDC) is capable of suppressing combustion Preliminary testing found increased valve lift provided better combustion phasing 2010 Emissions Search IVC Timing and Intake Pressure Sweeps Constant A/F Ratio IVC Sweep with Different Diesel Fuels • NOx decreased by factor of 2.5 solely through late IVC • 2010 NTE NOx and PM levels met through lowering temperature and increasing equivalence ratio through use of late IVC timing • Average decrease of 50% in PM emissions by using 2007 ULSD over pre-2007 #2 diesel fuel • Although enough oxygen is being entrained into the cylinder, the soot increases after a certain IVC timing since the combustion temperatures drop below necessary oxidizing temperatures • *** Pressure and NAHRR curves shown are of 2007 ULS Diesel fuel; combustion of fuels were similar • NOx decreases with IVC as well as intake pressure increase since intake air acts as a diluent • PM decreases with IVC by equivalence ratio increasing, and the necessary temperatures for oxidation are met