Methods and systems are provided for adjusting a location of a fuel injection in response to a substitution rate and a desired EGR flow. In one example, a method may include injecting a first fuel to a combustion chamber via a direct injector positioned to inject directly into the combustion chamber, injecting a second, different, fuel to the combustion chamber via an exhaust port injector positioned to inject toward an exhaust valve of the combustion chamber, and combusting the first and second fuels together in the combustion chamber.

Methods and systems are provided for injecting gaseous fuel during an engine start. In one example, a method comprises generating gaseous fuel via a fuel gasification device and injecting the gaseous fuel via a fuel injector. The fuel injector is configured to inject adjacent to an ignition device.

Operating an internal combustion engine system includes combusting gaseous hydrogen fuel and gaseous hydrocarbon fuel at a first substitution ratio in a plurality of cylinders in an engine, inputting an emissions cost value and a hydrogen cost value to a fuel blending control system for the engine, and determining, by way of an electronic control unit of the fuel blending control system, a fuel blending control term based on the respective cost values. Operating the engine system further includes varying admission of at least one of the hydrogen fuel or the hydrocarbon fuel to an intake system for the engine based on the fuel blending control term, and combusting the hydrogen fuel and the hydrocarbon fuel at a second substitution ratio produced by the varied admission in the plurality of cylinders in the engine.

The present disclosure describes an engine system that can achieve at least one of the followings: suppressing of generating of nitrogen oxides and suppressing of remaining of uncombusted hydrocarbons. The engine system has a combustion chamber to which air and a gas fuel are supplied, and is configured to combust the gas fuel. The engine system includes a liquid fuel injecting unit, and a control unit. The liquid fuel injecting unit is configured to inject a liquid fuel thereby to ignite the gas fuel. The control unit is configured to control the liquid fuel injecting unit. The control unit is configured to control the liquid fuel injecting unit so that injection of the liquid fuel is performed after a flame propagation after ignition of the gas fuel is ended.

A dual-chamber electrolysis vessel safely stores HHO gas for use by an internal combustion engine.

An intelligent fuel storage system can consist of a storage pod connected to a storage module with the storage pod having a plurality of separate storage vessels each residing below a ground level. The storage pod may concurrently store a first volume of a first fuel and a second volume of a second fuel prior to altering the first and second volumes in accordance with a performance strategy generated by the storage module to provide a predetermined blend of the first fuel and second fuel with at least a threshold volume and at least a threshold pressure.

An apparatus for use with a combustion apparatus and an associated Selective Catalytic Reduction (‘SCR’) device, comprises a temperature sensing device configured to measure the temperature of an exhaust from the combustion apparatus; and an injection unit configured to inject hydrogen into a feed of oxidizer to the combustion apparatus. An amount of hydrogen is added to an oxidiser feed of the combustion apparatus sufficient to reach a temperature in the exhaust of at least about 270° C.

Various methods and systems are provided for controlling emissions and a likelihood of engine knock during combustion in a multi-fuel engine. A method for an engine includes mixing an amount of a first fuel and an amount of a second fuel to combust a fuel mixture having a fuel ratio of the first fuel relative to the second fuel, the first fuel having a faster combustion flame speed relative to the second fuel, the fuel mixture having an air-to-fuel ratio with an amount of air delivered to the engine. The method further includes controlling either or both of a speed of combustion and a stability of combustion of the fuel mixture with the amount of air delivered to the engine by changing at least one of the fuel ratio, the air-to-fuel ratio, or both of the fuel ratio and the air-to-fuel ratio.

Methods and systems are provided for adjusting a substitution ratio based on water in a combustion mixture of a multi-fuel engine. In one example, a method includes adjusting a substitution ratio in response to an amount of water provided to a multi-fuel engine configured to combust a first fuel and a second fuel, the second fuel different than the first fuel.

Various methods and systems are provided for a method for a multi-pressure fueling system. In one example, the multi-pressure fueling system includes providing a first fuel delivery pressure enabling high pressure direct injection of a fuel at a first injector and a second fuel delivery pressure insufficient for high pressure direct injection, at a second injector, based on engine operation.