Economy and emission characteristics of the optimal dilution strategy in lean combustion based on GDI gasoline engine equipped with prechamber

EGR and excess-air dilution have been investigated in a 1.5 L four cylinders gasoline direct injection (GDI) turbocharged engine equipped with prechamber. The influences of the two different technologies on performance are explored. results show that at 2400 rpm 12 bar, can adopt more aggressive ignition advanced angle to achieve optimal combustion phasing. However, has greater fuel economy than owing larger in-cylinder polytropic exponent. As for prechamber, when ratio is 37.1%, phase advanced, resulting improving. Meanwhile, only under 36.2%, HC emissions lower original engine. With increase ratio, CO decrease continuously. NO X both 11% those Excess-air better very low emissions. effectively reduce emissions, but Compared spark plug ignition, pre chamber HC, higher At part load, pre-chamber reduces 49 ppm.