Reactivity controlled compression ignition engine operating on a Miller cycle with low pressure loop exhaust gas recirculation system and method

摘要

An internal combustion engine includes at least one cylinder having a reciprocable piston, an intake system directing intake air to the at least one cylinder, and an exhaust system directing exhaust gasses from the at least one cylinder. A first fuel injector disposed to inject a first fuel into the cylinder, and a second fuel injector disposed to inject a second fuel into said cylinder. At least one intake valve of said cylinder is configured to open and close with a variable timing in accordance with a Miller thermodynamic cycle. An exhaust gas recirculation system, provides exhaust gas to said cylinder through the intake valve. An electronic controller is disposed to monitor and receive at least one input signal indicative of the operating conditions of the internal combustion engine, and adjusts at least the amount of exhaust gas recirculation.

主权项

1. An internal combustion engine, comprising:
at least one cylinder having a piston reciprocable between top dead center (TDC) and bottom dead center (BDC) positions; at least one intake valve associated with the at least one cylinder, the at least one intake valve being configured to open and close and having an intake valve timing associated with such opening and closing, wherein the intake valve operates in accordance with a Miller thermodynamic cycle; an intake system directing intake air to the at least one intake valve; an exhaust system directing exhaust gasses from the at least one cylinder; a first fuel injector disposed to inject a first fuel into said cylinder; a second fuel injector disposed to inject a second fuel into said cylinder; a high pressure loop (HPL) exhaust gas recirculation (EGR) system and a low pressure loop (LPL) EGR system, each of the HPL and LPL EGR systems disposed to draw exhaust gas from the at least one cylinder and provide an amount of exhaust gas recirculation to the at least one intake valve; wherein the first fuel injector delivers a first injection of first fuel into the at least one cylinder; and wherein the second fuel injector delivers a second injection of second fuel and a third injection of second fuel into the at least one cylinder at different times such that a stratified mixture is formed in the at least one cylinder that includes first, second and third regions of different reactivities, the first region including a mixture of air and the first fuel, the second region containing a mixture of air, the first fuel and the second fuel and being disposed around a peripheral portion of the at least one cylinder, and the third region containing a mixture of air, the first fuel and the second fuel and being disposed around a central portion of the at least one cylinder; at least one sensor monitoring at least one engine operating parameter indicative of an ignition timing of the internal combustion engine; and an electronic controller disposed to:
receive at least one input signal from the at least one sensor indicative of the ignition timing,determine a desired amount of EGR that should pass through the HPL EGR system and the LPL EGR system based at least on an engine operating speed and an engine operating load; anddetermine an adjustment to the desired amount of EGR passing through the LPL EGR system based on said at least one input signal as an input parameter such that, when ignition timing is advanced, the desired amount of EGR passing through the LPL EGR system is caused to increase, and when ignition timing is retarded, the desired amount of EGR passing through the LPL EGR system is caused to decrease.