Methods and systems are provided for combusting an air-fuel mixture in a pre-chamber of a cylinder during an exhaust stroke of the cylinder responsive to fouling of the pre-chamber. In one example, a method may include injecting air into the pre-chamber during the exhaust stroke, injecting fuel into the pre-chamber during the exhaust stroke, and actuating a pre-chamber spark plug in order to combust the air-fuel mixture during the exhaust stroke. In this way, a temperature of the pre-chamber may be increased, which may decrease a soot load of one of a pre-chamber air-injector, a pre-chamber fuel injector, and the pre-chamber spark plug.

An auxiliary chamber (51) having a spark plug (54) and an auxiliary fuel injector is formed at the central part of the top surface of the main combustion chamber (2). When making an air-fuel mixture in the auxiliary chamber (51) burn by the spark plug (54), an air-fuel mixture in the main combustion chamber (2) is made to burn by jet flames ejected from the communicating holes (52). The injection ports of the auxiliary fuel injector (53) are oriented toward a tumble flow inflow peripheral region (R) which is located on the peripheral part of the end portion of the auxiliary chamber (51) at a place located on a side where the tumble flow W flows in from the communicating holes (52). When the tumble flow (W) is made to be generated in the main combustion chamber (2) by the tumble flow control valve (48), auxiliary fuel (QF) is injected from the auxiliary fuel injector (53) toward the tumble flow inflow peripheral region (R) of the auxiliary chamber (51).

There is described a system and method for controlling a temperature in the subchamber of a rotary engine. At least one first measurement of at least one engine operating parameter, a second measurement of the actual value of a temperature in the subchamber, and at least one third measurement of at least one aircraft operating parameter are received. A setpoint for the temperature in the subchamber is determined from the at least one first measurement and the at least one third measurement. At least one control signal is output to the engine for adjusting the actual value of the temperature in the subchamber towards the setpoint.

A method for controlling an internal combustion engine whereby, in a piston-cylinder unit provided with a prechamber, the quantity of propellant gas supplied to the prechamber is adjusted to regulate the operating characteristics of an inlet and/or outlet valve of the piston-cylinder unit.

A control system for a compression ignition engine configured to start compression ignition combustion by igniting mixture gas formed by injecting fuel into combustion chambers is provided, which includes combustion chambers each defined in respective cylinders so that displacements of the combustion chambers change by respective pistons reciprocating, a throttle valve, ignition plugs, injectors, a sensor having measuring parts including an atmospheric-pressure detector configured to detect an atmospheric pressure, and configured to measure parameters related to operation of the engine, and a controller. The controller executes a lean compression ignition combustion control in which compression ignition combustion is performed at a given lean air-fuel ratio higher than a stoichiometric air-fuel ratio. The controller restricts the execution of the lean compression ignition combustion control when the controller determines that the atmospheric pressure is lower than a given threshold based on a signal outputted from the atmospheric-pressure detector.

An auxiliary chamber having an auxiliary fuel injector is formed on the top surface of a main combustion chamber. When making the air-fuel mixture inside the auxiliary chamber burn, the air-fuel mixture inside the main combustion chamber is burned by jet flames ejected from a communicating hole. After engine startup and until the elapse of a wall surface lower temperature period where the wall surface temperature of the auxiliary chamber becomes a lower temperature than the wall surface temperature of the auxiliary chamber at the time of completion of warmup, an injection ratio of an injection amount of liquid fuel from the auxiliary fuel injector to a fuel injection amount from a main fuel injector is made to decrease compared with after completion of warmup.

An internal combustion engine, in particular a gas Otto-cycle engine, is provided. The internal combustion engine comprises a plurality of cylinders. Each cylinder is provided with a pre-chamber, and a pre-chamber gas supply conduit through which the pre-chamber can be supplied with fuel gas. The fuel gas is supplied to the pre-chambers by way of a pre-chamber gas valve associated with the respective pre-chamber. Also, an aperture is arranged between the pre-chamber gas supply conduit and the pre-chamber gas valve. At least one aperture associated with a pre-chamber gas valve has a through-flow coefficient such that pressure occurring at a maximum between combustion cycles in a volume between the pre-chamber gas valve and the aperture does not reach a pressure prevailing in the pre-chamber gas supply conduit.

The present invention discloses an ammonia-hydrogen fusion fuel diffusion combustion control system based on reactivity regulation, comprising an on-board ammonia-hydrogen fuel supply system, an ammonia-hydrogen fusion fuel diffusion combustion engine and an ECU; the ECU is used to control the intensity of a precombustion chamber jet flame, control the reactivity of a hydrogen-air mixture in a main combustion chamber and control the injection time of an ammonia ejector, thus to form diffusion combustion in the main combustion chamber; the on-board ammonia-hydrogen fuel supply system comprises a low-pressure ammonia fuel supply unit and an on-board hydrogen production unit, and is used to provide prepared low-pressure ammonia fuel and hydrogen for the ammonia-hydrogen fusion fuel diffusion combustion engine; before the formation of the precombustion chamber jet flame, hydrogen regulated by the ECU is firstly injected into the main combustion chamber by a first hydrogen ejector, and then the injection time of the ammonia ejector is controlled by the ECU to be slightly earlier than or synchronous with the formation of the precombustion chamber jet flame, so that ammonia fuel injected into the main combustion chamber is in a state of burning while injecting, thus to form diffusion combustion in the main combustion chamber.

Disclosed is an ammonia-hydrogen blended fuel control system based on reactivity regulation. The control system comprises a vehicle-mounted ammonia-hydrogen fuel supply system, an ammonia-hydrogen blended fuel premixed combustion engine and an ECU (Electronic Control Unit). The ECU is used for regulating the air injection amount and pressure value of ammonia fuel and hydrogen waiting to enter the ammonia-hydrogen blended fuel premixed combustion engine. The vehicle-mounted ammonia-hydrogen fuel supply system comprises a low-pressure liquid ammonia supply unit and a vehicle-mounted hydrogen production unit, and is used for providing the prepared low-pressure ammonia fuel and hydrogen for the ammonia-hydrogen blended fuel premixed combustion engine. The ammonia-hydrogen blended fuel premixed combustion engine comprises a turbulent jet ignition device provided with a pre-chamber. An ammonia injector and a first hydrogen injector which face the cylinder head are respectively arranged on the air inlet pipe.

A method for operating a spark ignited engine, including forming a combustible mixture by mixing generally homogeneously a first fuel and air and introducing this mixture into the at least one cylinder in an intake stroke, and compressing the combustible mixture with a piston in a compression stroke thereby introducing a part of the combustible mixture into a pre-chamber. During the intake and/or the compression stroke, a second fuel is introduced into the pre-chamber at an introduction-time before start of combustion, and the second fuel is of the same or different chemical composition and/or concentration with respect to the first fuel, and a spark ignites in the prechamber. An amount of second fuel and/or the chemical composition of second fuel introduced to the pre-chamber and/or spark timing of the pre-chamber and/or an in-cylinder charge temperature is chosen such that a desired duration of combustion can be achieved.