A method of controlling an internal combustion engine with a plurality of cylinders includes injecting a first gaseous fuel, at a first pressure, into at least a first cylinder of the cylinders, in a first combustion mode, and simultaneously providing a second gaseous fuel, at a second pressure which is different than the first pressure, for at least a second cylinder of the cylinders, in a second combustion mode which is dissimilar to the first combustion mode, wherein the second cylinder is not the first cylinder.

An engine system according to an exemplary embodiment of the present invention may include an engine including a plurality of cylinders; a fuel separator separating into a low-octane fuel and a high-octane fuel based on an octane number; a cylinder deactivation device deactivating some cylinders among the plurality of cylinder based on a driving region; a low-octane fuel injector injecting the low-octane fuel separated by the fuel separator into the plurality of cylinder; a high-octane fuel injector injecting the high-octane fuel separated by the fuel separator into the activated cylinders without being deactivated by the cylinder deactivation device; and a controller configured to control the cylinder deactivation device to deactivate some cylinders or activate all the cylinders, and to control the low-octane fuel injector and the high-octane fuel injector to inject the low-octane fuel or the high-octane fuel into the cylinders.

A first engine fuel, for example diesel fuel, is reformed (preferably via steam reforming) to produce syngas for use as a second engine fuel, with the fuels then both being used in an internal combustion engine to perform Reactivity Controlled Compression Ignition (RCCI). The syngas is produced and supplied to the engine as a supercritical fluid, thereby avoiding the pumping losses that would occur if syngas was pressurized for supply/injection. The reforming is done by a reformer which is provided as a unit with the engine (e.g., both the engine and reformer are onboard a vehicle), thereby effectively allowing use of a single fuel for RCCI engine operation.

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.

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

An engine operable in a premixed combustion system and a diffusion combustion system. The engine includes a main fuel injection valve, a pilot fuel injection valve, a liquid fuel tank, a main fuel supply path, a pilot fuel supply path, a pilot fuel filter, a pilot fuel high-pressure pump, a pilot fuel tank, and a pilot fuel supply pump. The pilot fuel tank stores pilot fuel sent from the pilot fuel high-pressure pump and not injected by the pilot fuel injection valve. This pilot fuel is sent to an automatic backwash filter and a pilot fuel filter while not passing through the liquid fuel tank.

An engine device including an engine capable of coping with both a premix combustion mode in which premixed fuel obtained by mixing fuel with air in advance is supplied into a cylinder and combusted and a diffusion combustion mode in which liquid fuel is injected into the cylinder and combusted. The engine device further includes a gas supply device configured to supply the gaseous fuel into the cylinder in the premix combustion mode; a pilot injection device configured to inject the liquid fuel into the cylinder in the premix combustion mode; and a main injection device configured to inject the liquid fuel into the cylinder in the diffusion combustion mode. The liquid fuel is injected from the main injection device and the liquid fuel is injected from the pilot injection device during the diffusion combustion mode, thus diagnosing failure in the pilot injection device.

A method of controlling a high pressure gas injection internal combustion engine includes injecting, in a first combustion mode, by a first as injection system, a first gaseous fuel into a cylinder of the engine, and accumulating in a container of a second gas injection system excess gaseous fuel from the first fuel system, shifting, in the cylinder, from the first combustion mode to a second combustion mode including determining a value of an air flow related parameter indicative of an air mass flow into the cylinder, determining, based on the determined air flow related parameter value, a value of a fuel flow related parameter indicative of a mass flow of the excess gaseous fuel, and supplying from the container, in accordance with the determined fuel flow related parameter value, the excess gaseous fuel to provide a premix of air and the excess gaseous fuel to the cylinder.

A fuel system for an internal combustion engine is provided including a first fuel container for a first fuel, a second fuel container for a second fuel, a pump, and a first fuel injector, the fuel system being arranged to provide a communication between the first fuel container and the pump and between the pump and the first fuel injector, and a reservoir with a separation device adapted to divide the reservoir into a first volume and a second volume, whereby the separation device may be moved or flexed by a pressure difference in the first and second volumes so as to change the sizes of the first and second volumes, wherein the fuel system is arranged to provide a communication between the pump and the first volume, and to provide a communication between the second fuel container and the second volume and between the second volume and a second fuel injector.

According to one or more embodiments, an internal combustion engine may be operated by a method including one or more of the steps of passing a first fuel and a second fuel into a combustion chamber of an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate the piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The engine cylinder may include a cylinder head and cylinder sidewalls, and the combustion chamber may be defined at least partially by the cylinder head, the cylinder sidewalls, and the piston. The first fuel may include a greater octane rating than the second fuel. The combustion chamber may include an end gas region and a central region, the central region more near to the spark plug than the end gas region. The first fuel and second fuel may be passed into the combustion chamber such that the end gas region has a greater concentration of the first fuel than the central region, and the central region has a greater concentration of the second fuel than the end gas region.