Abstract:
A system includes an internal combustion engine having a number of cylinders. At least one of the cylinders is a primary EGR cylinder that solely provides EGR flow during at least some operating conditions. Operation of the primary EGR cylinder is controlled separately from the other cylinders to reduce internal residuals in the primary EGR cylinder.
Abstract:
The present invention provides a method for realizing variable compression ratio and variable air-fuel ratio of an internal combustion engine, the method comprising the following steps: dividing an air intake volume in a cylinder into a first air intake volume and a second air intake volume, designing a compression ratio according to the first air intake volume and opening a throttle to enable the air intake volume to reach the first air intake volume; increasing the opening of the throttle to increase the air inflow to enable the second air intake volume to start the intake, the second air intake volume going beyond the first air intake volume, the compression ratio increasing with the increase of the air intake volume, the compression density of a fuel air mixture increasing with the increase of the compression ratio, and the air-fuel ratio reducing with the increase of the compression density of the fuel air mixture; and correcting, by an electronic control unit, a duration of ignition in real time according to a detonation signal fed back by a knock sensor, and controlling the fuel-injection quantity in real time to ensure the compression density required by the combustion of a lean fuel air mixture.
Abstract:
A method for starting a compression ignition engine having at least one cylinder with a reciprocating piston located therein, an intake valve configured to control the intake of air to an intake port of the cylinder and an exhaust valve configured to control the expulsion of gas from an exhaust port of the cylinder. The method includes the steps of: cranking the engine, conditioning intake air at the intake port of the cylinder to raise the temperature of air in the cylinder, controlling a valve timing the intake valve and/or the exhaust valve to allow the piston to compress the air within the cylinder, thereby increasing the temperature of the air within the cylinder, and injecting fuel into the cylinder when the air within the cylinder has been heated to a temperature sufficient to support compression ignition of a gasoline and air mixture within the cylinder.
Abstract:
Internal combustion engine comprising a plurality of cylinders with relative pistons, connected to a relative common drive shaft, said multitude of cylinders being divided into a first group and a second group of cylinders, in which consecutive ignition cycles alternate between the two groups of cylinders, the first group of cylinders being controlled to be always active, and the second group of cylinders being controlled to be active on request, the engine being characterised in that said first group of cylinders has a compression ratio different from a compression ratio of said second group of cylinders.
Abstract:
The invention relates to a method for operating an internal combustion engine in which a compression ratio is set to a setpoint compression ratio by means of an adjustment device, wherein in a normal operating mode of the internal combustion engine the setpoint compression ratio is determined as a function of an operating variable of the internal combustion engine. There is provision here that the internal combustion engine is at least temporarily operated in a prediction operating mode in which the setpoint compression ratio is determined on the basis of an anticipated estimated operating variable which is estimated on the basis of the instantaneous gradient of the operating variable over time. The invention also relates to an internal combustion engine.