MULTI-FUEL ENGINE WITH VARIABLE VALVE TIMING

摘要

In a compression ignition multi-fuel engine employing both port/intake manifold injection of fuel and in-cylinder injection of fuel, the recirculation of exhaust gas to the engine induction system is used to control the temperature and to set the reactivity of an air/fuel charge introduced to the engine for combustion. Fuel directly injected during compression of the charge controls ignition. A variable valve actuator for opening and closing an intake valve extends control over charge pressure and temperature to extend suppression of auto-ignition of the charge. Fuel injection strategy and variable valve actuation are subject to a control strategy to extend the benefits of premixed combustion.

主权项

1. An engine system comprising:
a cylinder having an intake port, an intake valve and an exhaust port, with the cylinder providing for compression of a charge received through the intake valve for combustion in the cylinder; an air induction sub-system coupled to the intake valve; a first fuel injector connected to inject a fuel into the air induction sub-system or the intake port for each charge; an exhaust gas recirculation line connecting exhaust gas produced by combustion of a charge and purged through the exhaust port to the air induction sub-system; a recirculated exhaust gas cooler; means for controlling recirculation of exhaust gas through the exhaust gas recirculation line and recirculated exhaust gas cooler to provide dilution and temperature control of the charge to suppress auto-ignition of the charge in the cylinder; and a second fuel injector connected to inject fuel into the cylinder near a level of peak compression for auto ignition and combustion of the charge.