A method and system are provided for adjusting a speed of a turbocharger compressor using an electric motor in response to a relative substitution rate of first and second fuels in a multi-fuel engine.

Timing of HHO gas injection into a 4-stroke engine is optimized based on engine operating parameters to improve fuel economy.

A device comprises: an injector for injecting fuel into an engine combustion chamber, a switch formed by an injector housing and an injector nozzle needle and which changes its switching state depending on a closed or open state of the injector, an input line for supplying energy to an actuating element which adjusts the nozzle needle in its two states, an output line for conducting energy away from the actuating element, and an evaluation unit for detecting the switching state of the switch, wherein a first switch contact of the switch is connected to an electrical input line of the injector, a second switch contact of the switch is connected to ground, and the evaluation unit is configured to carry out a signal measurementon the input line and/or an output line to conclude a switch state.

An internal combustion engine system for a vehicle includes an internal combustion engine, ICE, operable on a low cetane fuel and having a cylinder at least partly defining a combustion chamber and an ignition source for the low cetane fuel; a fuel injector for injecting the low cetane fuel into the combustion chamber; an ignition improver device in fluid communication with the fuel injector and further configured to supply an ignition improver fluid to the low cetane fuel; a control unit configured to selectively operate the ICE in a spark ignition, SI, mode and a compression ignition, CI, mode. The control unit determines an ICE operating condition and controls the ignition improver device to supply a given amount of ignition improver fluid to the low cetane fuel on the basis of said determined ICE operating condition.

In certain implementations, a ship propulsion system includes: at least one internal combustion engine with: a combustion chamber for burning a fuel; an intake tract for supplying fresh air to the combustion chamber; and a turbocharger with a compressor in the in-take tract; an electrolysis device for producing hydrogen gas for the internal combustion engine and for producing oxygen gas; an alcohol tank for supplying alcohols to the internal combustion engine; and a water tank, wherein the water tank and the alcohol tank are connected to the combustion chamber or a pressure side of the compressor for the supply of water and alcohol into the intake tract, and wherein the electrolysis device is connected to the pressure side of the compressor for supplying hydrogen gas into the intake tract or connected to the combustion chamber for supplying hydrogen gas into the combustion chamber.

A conventional gasoline engine is retrofitted and calibrated to operate as a bi-fuel engine using Hydrogen as the second fuel. When operated with Hydrogen, which typically leads to a reduction of engine output power, the engine is preferably operated in a charged mode and in a lean mode with the engine throttle kept in a wide-open position during charged and lean mode operation resulting in a more efficient engine with a reduction of engine output power loss.

An engine includes a reformer, a reforming-air adjuster, a reforming-fuel supply unit, a reformed-gas adjuster, and a control unit. The reformer is configured to reform fuel into a reformed gas. When a start signal is input, the control unit controls the reforming-air adjuster and the reforming-fuel supply unit to a reformable state in which the fuel is reformable in the reformer, and the control unit controls the reformed-gas adjuster so that the reformed gas flows through the reformed-gas adjuster with a degree of opening smaller than a normal degree of opening that is a degree of opening of the reformed-gas adjuster when composition of the reformed gas is in a stable state before the composition of the reformed gas becomes in the stable state, for a given period of time including at least a period immediately after the engine starts.

Methods and systems are provided for a multi-fuel engine. In one example, a method includes adjusting a substitution ratio based on an intake manifold temperature. The method further including adjusting the intake manifold temperature to increase the substitution ratio.

Various methods and systems are provided for venting fuel lines in a dual-fuel engine. In one example, a method may include in response to an engine shut-down request, venting fuel lines to remove hydrogen from the fuel lines.

Various methods and systems are provided for using only hydrogen as fuel in a duel fuel engine. In one example, a method may include direct injecting only hydrogen as fuel to one or more engine cylinders and compression igniting the injected hydrogen.