An internal combustion engine comprising: a main combustion chamber comprising at least one intake valve and at least one exhaust valve, wherein at least one intake port fluidically connected to an intake manifold is configured to supply an air and/or an air-fuel-mixture to the main combustion chamber via the at least one intake valve, and a pre-chamber which is in fluid connection with the main combustion chamber, wherein the pre-chamber is in fluid connection with the intake port and/or the intake manifold through a supply line, wherein at least one fuel injector is configured to enrich the air and/or air-fuel-mixture supplied to the main combustion chamber to have a lower ignition delay than an air-fuel-mixture supplied to the pre-chamber and/or air or air-fuel-mixture can be supplied to the pre-chamber to have a higher ignition delay than an air-fuel-mixture supplied to the main combustion chamber.

An internal combustion engine includes a housing defining an internal cavity, an inner body sealingly moving within the internal cavity for defining at least one combustion chamber of variable volume, a pilot subchamber in communication with the at least one working chamber, an ignition element in communication with the pilot subchamber, a main injector communicating with the at least one combustion chamber, and a pilot injector having a tip in communication with the pilot subchamber. The tip of the pilot injector includes at least a first injection hole defining a first spray direction and a second injection hole defining a second spray direction different from the first spray direction. The first spray direction extends toward the communication between the pilot subchamber and the at least one working chamber. A method of performing combustion in an internal combustion engine is also discussed.

A pre-chamber arrangement (100) for a gas engine (1), including a pre-chamber body (20) accommodating a volume (30); and a supply device (50) for supplying a gaseous medium (52) into the pre-chamber volume (30); wherein the pre-chamber body (20) has a bottom portion (22) with channels (40) for allowing gas to flow between the pre-chamber volume (30) and a main combustion chamber (10) of the gas engine (1). Each channel (40) extends along a channel axis (C) from an inner opening (42) facing the pre-chamber volume (30) to an outer opening (44) configured to face the main combustion chamber (10). The bottom portion (22) has a curved outer surface (24). The channels (40) are obliquely arranged in relation to a radius (r) of the bottom portion (22). The bottom portion has flat surfaces (46) surrounding the outer openings of the channels.

Internal combustion engine comprising at least one cylinder and a piston supported for repeated reciprocal movement in the cylinder so as to define a combustion chamber of an engine bore diameter A-A, the internal combustion engine further comprising an ignition device arranged in said cylinder having an igniter portion and an fuel injector which are both arranged in a pre-chamber, wherein the pre-chamber comprises a plurality of orifices for providing fluid communication between said pre-chamber and the combustion chamber, and wherein the plurality of orifices are of an overall orifice area so that the ratio between the overall orifice area and the engine bore diameter A-A ranges from 0.01 mm to 0.2 mm.

Aspects relate to zero-emission propulsion systems and generators using ammonia (NH.sub.3) as fuel for engines and power plants. While ammonia has poor flammability, mixing hydrogen with ammonia (NH.sub.3) may improve flammability and thus facilitate the ignition of an air/ammonia mixture in engines or power plants. Alternatively, hydrogen (H.sub.2) may be supplied in a separate fuel system as a pilot fuel for pilot ignition of an air/ammonia mixture. Hydrogen can also be used in air independent systems along with oxygen (O.sub.2) from an oxygen tank. In addition to hydrogen, other bio or fossil fuels can be used as pilot fuel for pilot ignition of an air/ammonia mixture. An advantage of using existing bio or fossil fuels for pilot ignition is that engines or power plants will have a pilot fuel system with sufficient capacity to maintain normal operations if ammonia is not available.

Aspects relate to zero-emission propulsion systems and generators using ammonia (NH.sub.3) as fuel for engines and power plants. While ammonia has poor flammability, mixing hydrogen with ammonia (NH.sub.3) may improve flammability and thus facilitate the ignition of an air/ammonia mixture in engines or power plants. Alternatively, hydrogen (H.sub.2) may be supplied in a separate fuel system as a pilot fuel for pilot ignition of an air/ammonia mixture. Hydrogen can also be used in air independent systems along with oxygen (O.sub.2) from an oxygen tank. In addition to hydrogen, other bio or fossil fuels can be used as pilot fuel for pilot ignition of an air/ammonia mixture. An advantage of using existing bio or fossil fuels for pilot ignition is that engines or power plants will have a pilot fuel system with sufficient capacity to maintain normal operations if ammonia is not available.

Auxiliary chamber type internal combustion engine has a main combustion chamber and an auxiliary chamber having an injection port through which the main combustion chamber communicates. The auxiliary chamber has a passage sectional area which is smoothly decreased toward the injection port. Further, the engine has a fuel injector injecting a fuel into the auxiliary chamber; an ignition plug igniting the fuel in the auxiliary chamber; and a swirl generating portion swirling a gas in the auxiliary chamber. The swirl generating portion swirls only the gas flowing into the auxiliary chamber from the main combustion chamber.

Auxiliary chamber type internal combustion engine has a main combustion chamber and an auxiliary chamber having an injection port through which the main combustion chamber communicates. The auxiliary chamber has a passage sectional area which is smoothly decreased toward the injection port. Further, the engine has a fuel injector injecting a fuel into the auxiliary chamber; an ignition plug igniting the fuel in the auxiliary chamber; and a swirl generating portion swirling a gas in the auxiliary chamber. The swirl generating portion swirls only the gas flowing into the auxiliary chamber from the main combustion chamber.

A system includes an engine having a main combustion chamber and a prechamber containing a spark plug. The prechamber is in fluid communication with the main combustion chamber through at least one orifice. An engine intake line provides intake air to the engine. An engine exhaust line receives exhaust gases from the engine. An exhaust gas recirculation line transports a portion of the exhaust gases from the engine exhaust line to the engine intake line, forming an exhaust gas recirculation loop through the engine. The system includes a reformer having a reactor containing a catalyst-coated substrate. The reformer generates a gaseous reformate from a fuel. The system includes a prechamber feed line to transport a stream of the gaseous reformate from the reformer to the prechamber.

A method for operating an internal combustion engine includes operating at least one cylinder pre-chamber in a homogeneous charge compression ignition (HCCI) combustion mode by providing an air/fuel mixture in the pre-chamber that is fluidly connected to the at least one engine cylinder, creating H and OH radicals in the pre-chamber to achieve an ignition in the at least one pre-chamber, determining whether an ignition timing is advanced or delayed relative to a desired timing, and delaying the ignition when the ignition is advanced relative to the desired timing by cooling the pre-chamber and the at least one engine cylinder.