The invention relates to a method (100) for operating a solenoid valve (1) for metering a fuel (2) in a fuel injection system (3). The solenoid valve can be actuated against a restoring force (12) by an electromagnet (11), wherein the time curve l(t) of the current I flowing through the electromagnet (11) and/or the time curve U(t) of the voltage U applied to the electromagnet (11) are detected during at least one opening process of the solenoid valve (1). The opening time t.sub.ON and the closing time t.sub.OFF of the solenoid valve (1) are evaluated (110) from the time curve I(t) and/or U(t), and the actual opening duration T.sub.T=t.sub.OFFt.sub.ON of the solenoid valve (1) is compared (140) with a reference value T.sub.R and/or the mass flow dm/dt flowing through the solenoid valve (1) is detected (120) and compared (142) with a reference value M.sub.R during at least one opening process of the solenoid valve (1); and/or a leakage dm/dt of fuel (2) through the solenoid valve (1) is detected (130) in the closed state of the solenoid valve (1). The invention also relates to a corresponding controller (5), a fuel injection system (3), and a computer program product.

It is a challenge to reduce unburned hydrocarbon emissions for gaseous fuelled engines, especially at low engine load conditions, to meet demanding emission regulation targets. A method for reducing unburned hydrocarbon emissions in a lean-burn internal combustion engine that is fuelled with a gaseous fuel comprises adjusting the timing for closing of an intake valve as a function of engine operating conditions by one of advancing timing for closing of the intake valve and closing the intake valve earlier during an intake stroke; and retarding timing for closing of the intake valve and closing the intake valve later during a compression stroke. The volumetric efficiency of the internal combustion engine is reduced and unburned hydrocarbon emissions are maintained below a predetermined level.

A precombustion-chamber type gas engine, comprising includes: a check valve disposed in the precombustion-chamber gas supply passage and configured to block a backflow of fuel gas from a precombustion chamber; a supply pressure control valve which is disposed on an upstream side of the check valve in the precombustion-chamber gas supply passage and which is capable of adjusting a pressure of the fuel gas to be supplied to the precombustion chamber; a torch strength information acquisition device configured to obtain torch strength information correlated to strength of a torch from the injection nozzle, on the basis of a pressure in the main chamber and a pressure in the precombustion chamber; a precombustion-chamber gas supply amount calculation device configured to calculate an amount of the fuel gas to be supplied to a precombustion-chamber gas supply amount, on the basis of the torch strength information and correlation information representing a correlation between the torch strength information, a thermal efficiency, and the precombustion-chamber gas supply amount; and a precombustion-chamber gas supply pressure control device configured to control the supply pressure control valve on the basis of the precombustion-chamber gas supply amount calculated by the precombustion-chamber gas supply amount calculation device.

A method for operating an internal combustion engine including feeding a pilot quantity of gas fuel, into a prechamber before a piston reaches a top dead center position. The method comprises autoignition of the pilot quantity of gas fuel in the prechamber, feeding a main quantity of gas fuel into the prechamber after the autoignition, and ignition of the main quantity of gas fuel by the conditions in the prechamber that are brought about by the autoignited pilot quantity. The method makes it possible to operate an internal combustion engine purely with methane or some other gaseous fuel, by means of compression autoignition of the pilot quantity.

An opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is directly side-injected into the cylinder in a compression stroke of the opposed-piston engine, mixed with charge air in the cylinder, and auto-ignited in a combustion chamber formed in the cylinder between the pistons during the compression stroke. A method of operating the hydrogen opposed-piston engine includes switching between a first ignition mode using an externally-generated ignition impulse to ignite the mixture of hydrogen fuel and charge air, and a second ignition mode using compression to ignite the mixture.

Low-cost fuel injection systems for internal combustion engines, including vapor fuel engines are provided.

The electronic control unit performs a retarding process of retarding the ignition timing when the fuel pressure decreases, and lowers the peak of the combustion pressure in the cylinder, thereby suppressing the inflow of the combustion gas to the injector. Further, the electronic control unit performs an increasing process of increasing the injection amount of the hydrogen gas together with the retarding process, thereby suppressing the torque decrease of the engine due to the retard of the ignition timing.

A hydrogen fueled powerplant including an internal combustion engine that drives a motor-generator, and has a two-stage turbocharger, for an aircraft. A control system controls the operation of the motor-generator to maintain the engine at a speed selected based on controlling the engine equivalence ratio. The control system controls an afterburner, an intercooler and an aftercooler to maximize powerplant efficiency. The afterburner also adds power to the turbochargers during high-altitude restarts. The turbochargers also include motor-generators that extract excess power from the exhaust.

An engine includes a cylinder, a piston, an ignition device, a rotation sensor, an intake temperature sensor, an intake pressure sensor, and a control device. The ignition device ignites a gas mixture. The rotation sensor measures the rotation speed of a crankshaft. The intake temperature sensor measures the temperature of the gas mixture. The intake pressure sensor measures a first pressure value of the gas mixture. The control device controls the hydrogen equivalent ratio of hydrogen contained in the gas mixture and/or timing of igniting the gas mixture based on the rotation speed, the temperature of the gas mixture, and the first pressure value of the gas mixture.

A two-stroke cycle uniflow-scavenged opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is injected into the cylinder early in a compression stroke of the opposed-piston engine, and is ignited in a combustion chamber formed between the pistons late in the compression stroke.