An engine system of the present disclosure includes an engine configured to drive a plurality of pistons by burning a mixture of air and gas, an air supply pipe through which the air supplied to the engine flows, a supercharger configured to compress the air flowing through the air supply pipe, a gas supply pipe through which the gas supplied to the engine flows, and a mixer configured to mix the air that has passed through the supercharger and the gas. The mixer has a venturi tube shape in which a cross-sectional area of a flow path decreases and expands in a flow direction of the air that has passed through the supercharger, and the gas supply pipe is connected to a portion of the mixer where the cross-sectional area of the flow path in the mixer is decreased.

A fuel delivery arrangement for a generator can include a throttle-mixing assembly including a mixer body defining a main port extending between an air inlet end and a mixed air-fuel outlet end and defining a fuel inlet port extending into the main port, a Venturi structure located within the main port and being configured to mix fuel received from the fuel inlet port with air received from the air inlet end and to deliver an air-fuel mixture to the air-fuel outlet, a fuel control valve assembly, mounted to the mixer body, including a first valve and a first actuator arranged to control a flow of the fuel passing through the fuel inlet port, and a throttle control valve assembly, mounted to the mixer body, including a second valve and a second actuator arranged to control a flow of the air-fuel mixture passing through the main port.

Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

A system for introducing a gaseous fuel to an internal combustion engine includes a fuel storage device, a compressor, and an air and fuel conduit in fluid communication with the fuel storage device and with the compressor. The air and fuel conduit includes a first passage and a second passage that includes a first portion and a second portion, the second portion being a venturi portion, the second passage being fluidly connected to the compressor in parallel with the first passage.

An engine includes a cylinder, a piston reciprocable within the cylinder in response to the combustion of a mixture of air and fuel, and a venturi having a throat. The venturi is positioned to draw in air and direct the air and fuel to the cylinder. A fuel inlet is positioned to direct gaseous fuel into the throat, a valve is coupled to the fuel inlet, and an engine control module operable to control the valve and the fuel flow into the throat.

A supplemental fuel system includes a fuel mixer. The fuel mixer includes a nozzle and a stem. The nozzle is configured to be positioned within a conduit of an air supply system for a compression-ignition engine. The nozzle has a body defining a first inlet positioned at a first nozzle end thereof, an outlet positioned at a second nozzle end thereof, a second inlet positioned between the first nozzle end and the second nozzle end, and a nozzle passage extending from the first nozzle end to the second nozzle end that is configured to receive air flowing through the conduit. The stem has a first stem end interfacing with the second inlet. The stem is configured to extend through a wall of the conduit such that a second stem end is positioned outside of the conduit.

Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.

A carburettor for supplying gaseous fuels in internal combustion engines, comprises a main body in which there are defined an intake section, a first pressure reduction section, a second pressure reduction section connected to the first section, a supply section connected to the second pressure reduction section, a Venturi device connected to the supply section, wherein the Venturi device forms a central portion of the carburettor, the first pressure reduction section and the supply section extending on opposite sides of the Venturi device, the second supply section being interposed between the first pressure reduction section and the supply section and wherein the supply section further comprises an actuating device that can to allow passage of gas through a third connecting conduit towards the third chamber.

A gas mixer for mixing a first gas and a second gas, having a first, outer gas housing part, having an inlet for the first gas in a longitudinal axis and an inlet for the second gas in a transverse axis, a second, interior gas housing part set into the first gas housing part to form an annular space for a second gas, having a mixing space into which the first gas and the second gas are introduced for mixing. The first and second gas housing parts and the annular space are aligned along the longitudinal axis and the mixing space is aligned cylindrically along the longitudinal axis. A mixing device having a plurality of hollow rods is arranged in the mixing space. A hollow space of a hollow rod is in fluid communication on both sides with the annular space. The number of hollow rods extends transverse to the longitudinal axis and the transverse axis and at least one hollow rod has a plurality of openings for the second gas, so that the hollow space is in fluid communication with the cylindrical mixing space.