A method of combusting hydrogen gas in an engine cylinder to initiate a diffusion combustion process, the engine cylinder having a cylinder piston which is driven by means of a crankshaft between bottom dead centre (BDC) and top dead centre (TDC) to perform a compression stroke. The method comprises delivering a pilot injection of hydrogen gas into a combustion chamber during the compression stroke so that the pilot injection of hydrogen pre-mixes with the air and forms an ignitable air/hydrogen gas mixture in the vicinity of an engine cylinder spark plug; generating a spark with a spark plug to ignite the ignitable air/hydrogen gas mixture to generate a primary combustion event which results in a fuel burn and a cloud of primary gas; and delivering a main injection of hydrogen gas directly into the burning cloud of primary gas so that the main injection of hydrogen gas ignites in the compression stroke to deliver a secondary combustion event.

An internal combustion engine comprising the fuel injector arranged in the combustion chamber. The primary fuel injection and the secondary fuel injection from the fuel injector are successively performed to cause autoignition of an injected fuel of the primary fuel injection and autoignition of an injected fuel of the secondary fuel injection. A temperature region suppressing change of an ignition delay time where a change of ignition delay time with respect to a rise in temperature in the combustion chamber is suppressed appears in the compression stroke at a temperature in the combustion chamber of 700K to 900K. The secondary fuel injection is performed if the temperature in the combustion chamber is a temperature within the temperature region suppressing change of the ignition delay time during the compression stroke. The primary fuel injection is performed during the compression stroke or suction stroke before the temperature in the combustion chamber reaches a temperature in the temperature region suppressing change of the ignition delay time at a fuel injection timing at which the injected fuel of the secondary fuel injection is autoignited after the injected fuel of the primary fuel injection is autoignited.

In one embodiment, a combustion system for an engine is disclosed. The system includes a cylinder block that defines a cylinder bore and opposing pre-chambers located along a circumference of the cylinder bore. The system also includes a fuel injector located equidistant from the circumference of the cylinder bore that injects fuel in a direction perpendicular to a diameter of the cylinder bore. The system further includes spark plugs located within the pre-chambers that ignite at least a portion of the fuel from the fuel injector to direct ignition flames into the cylinder bore.

The invention relates to a control device applied to a cylinder injection type of an internal combustion engine (10). The control device control a disperse parameter for changing a degree of a spread of the fuel spray injected from the injector (20) such that the maximum degree of the spread of the fuel spray under a state where an amount of the fuel adhering to the spark generation part (31a) of the spark plug (30) at the ignition timing corresponds to a first amount, is smaller than the maximum degree of the spread of the fuel spray under a state where the amount of the fuel adhering to the spark generation part at the ignition timing corresponds to a second amount smaller than said first amount.

Methods and systems are provided for adjusting a compression ratio of a combustion chamber. In one example, a method may include altering an axial position and rotational orientation of a control element comprising a spark plug and a fuel injector in response to an engine operation. The method further includes changing a distance between intake and exhaust valves of a cylinder to the control element, the spark plug, and the fuel injector.

Injection of the fuel by the injector 43 creates a gas flow in the combustion chamber. The gas expands in a radial fashion from an axis of a cylinder toward a radial outside of the cylinder, and then flows from the radial outside along the cylinder head bottom face 221 toward the axis of the cylinder. The spark plug 41 has a gap positioned away from the axis of the cylinder toward the radial outside of the cylinder at a predetermined distance, and placed radially inwardly from a position opposite a rim of an opening of the cavity 242. A side electrode extends to be oriented in a direction perpendicular to the flow of the gas along the cylinder head bottom face. The gap has a center positioned near the cylinder head bottom face, and closer to an interior of a combustion chamber than to the cylinder head bottom face.

An internal combustion engine, system includes an internal combustion engine for combustion of gaseous fuel and having a combustion chamber at least partially delimited by a cylinder; a reciprocating piston moveable within said cylinder between a bottom dead centre (BDC) and a top dead centre (TDC), The reciprocating piston has a piston top end comprising a piston bowl intended to form part of the combustion chamber. A controllable fuel injector is arranged to inject gaseous fuel into the combustion chamber and towards the piston bowl. A controller controls the fuel injector to inject at least one gaseous fuel jet toward a bottom surface of the piston bowl during a fuel injection period occurring prior to an ignition event of the gaseous fuel.

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas to enable minimal, or no, generation of soot and/or other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. An ignition assist component can be located downstream of the duct to facilitate ignition of the fuel/charge-gas mixture.

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas to enable minimal, or no, generation of soot and/or other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. The various technologies presented herein can be utilized in a number of combustion systems, such as compression-ignition (CI) reciprocating engines, spark-ignition (SI) reciprocating engines, gas-turbine (GT) engines, burners and boilers, wellhead/refinery flaring, etc.

A piston for an internal combustion engine includes a piston body forming a crown portion and a skirt portion. The skirt portion includes a bore that receives a pin for connecting the piston to a connecting rod, and the crown portion forms a bowl surrounded by a flat crown surface having an annular shape and disposed along a plane. The bowl and the flat crown surface meet along a circular edge surrounding a rim of the bowl. The piston further includes an annular protrusion disposed within the bowl adjacent the rim. The annular protrusion has a generally convex shape in cross section created by an upper, inwardly extending surface and a lower, inwardly extending surface that meet along a convex apex. The piston further includes an airfoil surface formed in the flat crown surface. The airfoil surface has a convex shape and extends annularly around the rim of the bowl.