A method of controlling a dual fuel engine configured to receive a first fuel and a second fuel includes operating the engine using the first fuel, measuring a current load of the engine, sending a first signal to a first fuel system to deliver an amount of the first fuel to the engine, and determining at least one first operating parameter associated with the engine. The method also includes determining an engine load estimate based on the first signal and the at least one first operating parameter, comparing the engine load estimate to the measured load, and based on the comparison, determining, an adjusted engine load estimate to compensate for a drift in the first fuel system.

A controller for determining an injection strategy for a fuel injector within a hydrogen fuel injection system within an engine, the controller comprising: an input arranged to receive an engine operating parameter and a pressure signal associated with the pressure of hydrogen fuel available for injection from the injector in the fuel injection system; a processor arranged to determine an injection strategy for the injector in dependence on the received pressure signal and engine control parameter, the determined injection strategy comprising one or more injector control signals to control operation of the fuel injector; an output arranged to output the one or more control signals to the fuel injector.

A fuel supply device includes a fuel tank, a delivery pipe in which gas fuel to be supplied to a fuel injection valve is stored, a supply passage through which the fuel gas supplied from the fuel tank to the delivery pipe flows, a shut-off valve provided in the supply passage, an oil supply device that supplies oil to a downstream portion of the supply passage, and a controller. The controller executes an oil supply process during operation of the internal combustion engine to close the shut-off valve to stop the supply of the gas fuel to the delivery pipe, and supply the oil to the downstream portion by the oil supply device when the pressure in the delivery pipe has dropped.

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.

A system for a vehicle, the system comprising a hydrogen fuel storage system for storing hydrogen fuel; a recirculation hydrogen fuel system for transporting hydrogen fuel, the recirculation hydrogen fuel system having a fuel inlet configured to be in fluid communication with the hydrogen fuel storage system and further a fuel return line to the hydrogen fuel storage system, wherein the recirculation hydrogen fuel system is configured to be in fluid communication with a hydrogen fuel-consuming power source, the system further comprising an electrically powered compressor disposed in the recirculation hydrogen fuel system; and wherein the electrically powered compressor is controllable to pressurize hydrogen fuel in the recirculation hydrogen fuel system in response to a determined need for dissipating energy.

A hydrogen combustion engine arrangement includes a source of hydrogen, an internal combustion engine having at least one cylinder having an inlet opening connected by first hydrogen supply line to the source of hydrogen and an outlet opening, an exhaust aftertreatment system connected by an exhaust line to the outlet opening of the at least one cylinder, the EATS including a selective catalytic reduction system (SCR), a combustion zone upstream of the SCR, the combustion zone being connected to the source of hydrogen by a second hydrogen supply line, and an arrangement for determining a temperature in the EATS, and a computer system configured to control delivery of hydrogen to the EATS in response to a signal from the temperature determining arrangement.

A piston for an internal combustion engine operable on a gaseous fuel is provided. The piston has a piston top end comprising a piston bowl for receiving at least one gaseous fuel jet from a fuel injector of the ICE, said piston bowl having a bottom section and a circumferential side section extending in an axial direction between the bottom section and a piston top end surface, wherein said bottom section comprises a protrusion segment configured to guide said at least one gaseous fuel jet. The protrusion segment further extends between spaced apart regions of the circumferential side section.

A fuel injector for an internal combustion engine comprising an injection nozzle comprising a nozzle body with a nozzle bore; a valve needle assembly received within the nozzle bore and including a valve needle engageable with a seat region to control fuel delivery through an outlet of the injection nozzle; and a first actuator arrangement operable to apply an opening force to an engagement region of the valve needle assembly to cause an opening movement thereof. The first actuator arrangement comprises a first conductive coil mounted concentrically on a first body and a first armature configured to apply the opening force to the valve needle assembly. The first body comprises a first, radially inner region having a relatively high magnetic permeability and a second region having a relatively low magnetic permeability, the second region being disposed radially between the first coil and the first, radially inner region.

A fuel supply device includes a fuel tank, a delivery pipe in which gas fuel to be supplied to a fuel injection valve is stored, a supply passage through which the fuel gas supplied from the fuel tank to the delivery pipe flows, a shut-off valve provided in the supply passage, an oil supply device that supplies oil to a downstream portion of the supply passage, and a controller. The controller executes an oil supply process during operation of the internal combustion engine to close the shut-off valve to stop the supply of the gas fuel to the delivery pipe, and supply the oil to the downstream portion by the oil supply device when the pressure in the delivery pipe has dropped.

Provided is a fuel-reforming device comprising: an ammonia tank (4); a reformer (5) for reforming ammonia and generating high-concentration hydrogen gas having a hydrogen content of at least 99%; a mixing tank (7) for mixing ammonia and hydrogen for temporary storage; and a control means (10) for controlling the respective supply amounts of ammonia and high-concentration hydrogen gas that are supplied to the mixing tank (7). The control means (10) calculates the combustion rate coefficient C of mixed gas with respect to a reference fuel on the basis of equation (1). Equation (1): S.sub.0=S.sub.HC+S.sub.A(1C). In equation (1), S.sub.0 is the combustion rate of the reference fuel, S.sub.H is the combustion rate of hydrogen, S.sub.A is the combustion rate of ammonia, and C is the combustion rate coefficient of mixed gas. In addition, on the basis of equation (2), the control means (10) determines the volume fractions of ammonia and hydrogen that are supplied to the mixing tank. Equation (2): C=1exp(AM.sub.B). In equation (2), M is the volume fraction of hydrogen in mixed gas, and A and B are constants.