Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

A method of controlling a dual fuel engine system includes adjusting a phasing control parameter such as air-fuel ratio (AFR), based on a phasing signal to limit an error in a phasing of combustion of gaseous fuel. The cylinder is switched to a dual fuel liquid pilot-ignited mode by commanding direct injection of an early pilot shot of liquid fuel, based on the adjustment to the phasing control parameter, and production of a spark to ignite gaseous fuel in the cylinder. Switching the cylinder to the dual fuel liquid pilot-ignited mode is completed by commanding direct injection of an early pilot shot and a second pilot shot of liquid fuel to ignite gaseous fuel in response to combustion of the early and second pilot shots in the cylinder.

Various embodiments include a method for starting an internal combustion engine comprising: in a first phase after a starting process, setting a throttle valve to a value near to zero so the pressure in the intake tract is lowered below the ambient pressure and injecting a fuel into the intake tract above a rich combustion limit at which the fuel/air mixture would still just be combustible; in a second phase, reducing the fuel mass as a function of the pressure; in a third phase shorter than the second phase, further reducing the fuel mass and increasing the opening of the throttle valve to increase the pressure in the intake tract; and in a fourth phase, increasing the fuel mass as a function of rising pressure in the intake tract.

A method for controlling an internal combustion engine whereby, in a piston-cylinder unit provided with a prechamber, the quantity of propellant gas supplied to the prechamber is adjusted to regulate the operating characteristics of an inlet and/or outlet valve of the piston-cylinder unit.

A method for controlling an internal combustion engine whereby, in a piston-cylinder unit provided with a prechamber, the quantity of propellant gas supplied to the prechamber is adjusted to regulate the operating characteristics of an inlet and/or outlet valve of the piston-cylinder unit.

A method for operating an internal combustion engine that is supplied with lubricating oil via an oil circuit. A measurement value of the total base number and/or a measurement value of the oxidation of lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the oxidation an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit and new lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

A method for operating an internal combustion engine that is supplied with lubricating oil via an oil circuit. A measurement value of the total base number and/or a measurement value of the oxidation of lubricating oil currently used in the oil circuit for the lubrication is detected. Dependent on the established measurement value of the total base number and/or dependent on the established measurement value of the oxidation an exchange oil quantity for the oil circuit is determined. Currently used lubricating oil to an extent corresponding to the exchange oil quantity is removed from the oil circuit and new lubricating oil to an extent corresponding to the exchange oil quantity is supplied to the oil circuit.

An estimation device is applicable to a combustion system including an internal combustion engine and includes a mixing acquisition unit, a main region estimation unit, and an after region estimation unit. The mixing acquisition unit acquires a mixing ratio of various components contained in the fuel used for combustion in the internal combustion engine. The main region estimation unit estimates a combustion region of the fuel as a main combustion region for a main combustion produced by injecting the fuel into a combustion chamber of the internal combustion engine by main injection, based on the mixing ratio acquired by the mixing acquisition unit. The after region estimation unit estimates an injection region of the fuel as the after combustion region based on the mixing ratio, for an after combustion produced by injecting the fuel into the combustion chamber by an after injection, after the main injection in one combustion cycle.

An estimation device is applicable to a combustion system including an internal combustion engine and includes a mixing acquisition unit, a main region estimation unit, and an after region estimation unit. The mixing acquisition unit acquires a mixing ratio of various components contained in the fuel used for combustion in the internal combustion engine. The main region estimation unit estimates a combustion region of the fuel as a main combustion region for a main combustion produced by injecting the fuel into a combustion chamber of the internal combustion engine by main injection, based on the mixing ratio acquired by the mixing acquisition unit. The after region estimation unit estimates an injection region of the fuel as the after combustion region based on the mixing ratio, for an after combustion produced by injecting the fuel into the combustion chamber by an after injection, after the main injection in one combustion cycle.

Premixed engines have ignition issues when engine speed and load are below a predetermined range. An ignition apparatus for igniting a premixed charge in a gaseous-fueled internal combustion engine comprises an ignition device associated with a combustion chamber of the internal combustion engine. There is at least one of a dilutant injector for introducing a diluting agent that forms a stratified charge around the ignition device and an enrichment injector for introducing gaseous fuel that forms a stratified charge around the ignition device. An electronic controller is operatively connected with the ignition device and the at least one of the dilutant injector and the enrichment injector and programed to at least one of actuate the dilutant injector to introduce the diluting agent when the ignition device decreases a local air-fuel equivalence ratio around the ignition device below a predetermined threshold; and actuate the enrichment injector to introduce the gaseous fuel to decrease the local air-fuel equivalence ratio when engine load and engine speed are below a predetermined threshold engine load and speed range and when the ignition device does not affect the local air-fuel equivalence around the ignition device.