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.

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.

To effectively suppress strong knock that occurs in the operating region of high load and high rotation in a specific engine having a pre-chamber in a combustion chamber, the engine includes a piston that defines a combustion chamber together with a cylinder block and a cylinder head. The combustion chamber includes a sub-chamber and a main chamber separated from the sub-chamber by a pre-chamber. The specific ratio obtained by dividing a volume of the sub-chamber by a stroke volume of a cylinder is greater than or equal to 0.00005 and less than or equal to 0.00045.

To meet both a request to improve the thermal efficiency in the medium load operation of an engine and a request to suppress knocking in the high load and high rotation operation of the engine, the engine includes a main combustion chamber comprising a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24. A first index, which is the product between a total cross-sectional area of the plurality of injection holes and the compression ratio, is not less than 0.1496 cm.sup.2 and not more than 0.8449 cm.sup.2.

To meet both a request to improve the thermal efficiency in the medium load operation of an engine and a request to suppress knocking in the high load and high rotation operation of the engine, the engine includes a main combustion chamber including a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that are open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24. A second index that is a product between a volume of the pre-chamber and the compression ratio is not less than 1.03 cm.sup.3 and not more than 5.92 cm.sup.3.

A dual fuel engine is provided. The dual fuel engine includes an engine cylinder and a piston disposed within the engine cylinder. The dual fuel engine includes a cylinder head coupled to the engine cylinder and a fuel injector coupled to the cylinder head. The fuel injector is adapted to supply a first fuel to the engine cylinder. The dual fuel engine further includes a pre-combustion chamber coupled to the cylinder head at a predetermined distance from the fuel injector. The pre-combustion chamber is in fluid communication with the engine cylinder via at least one conduit and the pre-combustion chamber is adapted to receive a second fuel and an air mixture. The second fuel is different from the first fuel. The dual fuel engine further includes a spark plug structured and arranged within the pre-combustion chamber and the spark plug is adapted to ignite the second fuel within the pre-combustion chamber.

Methods and systems are provided for operating a pre-chamber to provide ignition to a cylinder during catalyst heating. In one example, a method may include injecting fuel and air into a pre-chamber of an engine cylinder during an expansion stroke of the engine cylinder responsive to a temperature of a catalyst being less than a threshold temperature, and injecting the fuel and the air into the pre-chamber during a compression stroke of the engine cylinder responsive to the temperature of the catalyst being greater than or equal to the threshold temperature. In this way, the pre-chamber may provide robust ignition to the cylinder during a variety of operating conditions.

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.

Systems, devices, and methods described herein provide one or more radical chemicals generators (RCGs) and/or mini-chambers (M-Cs) that can be used to provide enhanced radical ignition (ERI) in an internal combustion engine. RCGs as described herein can include quenching systems (QSs) that can be configured to quench a flame of combustion products to produce a jet of partial combustion products containing radical species (RS). The jet of partial combustion products can be injected to a main combustion chamber (MCC) of an engine to induce ERI. ERI can proceed under leaner fuel conditions and lower temperatures compared to those needed for conventional thermally induced, fuel oxidation chain initiation reaction processes.

A combustion engine having at least one cylinder, wherein the at least one cylinder has a main combustion chamber for burning a fuel/air mixture or a fuel/air/exhaust gas mixture and has a flushed prechamber connected to the main combustion chamber via at least one overflow duct on the fluid side, and comprises at least one exhaust gas turbocharger which has a turbine for the expansion of the at exhaust gas leaving the at least one cylinder and a compressor for compressing fresh air or a fresh air/exhaust gas mixture to be supplied to the at least one cylinder as compressed charge-air. For the supply of the combustion chamber, a combustion chamber charge-air line is disposed in a charge-air line downstream of the compressor and for the supply of the prechamber, a prechamber flushing line branching off at an extraction point is formed.