Operating an engine includes injecting a first charge of liquid fuel using a first set of nozzle outlets in a fuel injector, and injecting a second charge of liquid fuel using a second set of nozzle outlets in a fuel injector. The first charge is autoignited in a first engine cycle, and the second charge is autoignited in a second engine cycle, and may be used to pilot ignite a charge of gaseous fuel. Operating the engine further includes limiting errors in targeting of the second charge of liquid fuel caused by transitioning the engine from a first combination to a second combination of speed, load, and boost, by varying an injection pressure of the liquid fuel from the first engine cycle to the second engine cycle.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

The method for controlling the operation of an internal combustion engine comprises at least two operating modes. In a first operating mode, the intake valve is closed at a first predetermined crank angle, in accordance with the Miller cycle, before the piston reaches bottom dead center during the intake stroke for reducing pressure in the cylinder, and fuel is injected using first fuel injection means optimized for large amounts of fuel. In a second operating mode the intake valve is closed at a second predetermined crank angle, in accordance with conventional intake valve closing timing, after or slightly before the piston has passed bottom dead center, and fuel is injected using second fuel injection means optimized for small amounts of fuel. The invention also concerns an internal combustion engine.

An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

In a dual-fuel fuel injector comprising a first injector unit for a first injector operating mode using a first main fuel and a second injector unit for a second injector operating mode using a second main fuel and an injector-reservoir, the reservoir is connected at one end to a first main fuel supply and at the opposite end to a second main fuel supply with a separating element disposed in the injector reservoir so as to be movable between the opposite ends so that, in each operating mode, the full volume of the reservoir can be used for accommodating the respective main fuel.

A multi-fuel injector assembly in one embodiment includes a first fuel injector assembly to deliver a first type of fuel and a second fuel delivery system to deliver a second type of fuel. The first fuel injector includes a first nozzle, at least one first needle, and at least one first actuator configured to move the at least one first needle. The at least one first actuator moves the at least one first needle to a first fuel delivery configuration that corresponds to a first fuel mixture composition, and a second fuel delivery configuration that corresponds to a second fuel mixture composition.

A liquid fuel injector such as for a dual fuel system in an internal combustion engine includes two-way injection control valves for controlling twin outlet checks. A first set of orifices are arranged in an A-F-Z pattern, and a second set of orifices are arranged in an A-F-Z pattern, within the fuel injector, among a high-pressure inlet passage, a low-pressure space, and first and second outlet check control chambers, respectively. A common nozzle supply cavity is fluidly connected to the high-pressure inlet passage and supplies each of two sets of nozzle outlets opened and closed by the twin outlet checks.

A fuel nozzle for a combustor includes a fuel body, a primary fuel passage having a primary fuel outlet, and a secondary fuel passage having a secondary fuel outlet, the secondary fuel passage being non-concentric with the primary fuel passage. The primary fuel outlet and the secondary fuel outlet are non-parallel. An axial centerline of the primary fuel outlet is angled with respect to an axial centerline of the primary fuel passage and an axial centerline of the secondary fuel outlet is colinear with an axial centerline of the secondary fuel passage. Also provided is a method of introducing non-concentric, non-parallel fuel flows to a combustor is also provided.

A fuel injector includes a nozzle assembly having a nozzle case, and a concentric check assembly within the nozzle case. Transfer passages are formed in an outer check of the check assembly, and spray orifices are formed in the nozzle case. A fuel volume is formed between the outer check and an inner check, and the inner check is movable to fluidly connect the transfer passages to the fuel volume. The outer check is rotatable between a first angular orientation and a second angular orientation to fluidly connect separate sets of the transfer passages to separate sets of the spray orifices. Spray ducts are in spray path alignment with at least one of the sets of spray orifices.