An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

A carburetor 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 carburetor, 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 method for operating an internal combustion engine, having of the following steps: operating the internal combustion engine with a gas fuel; detecting a lambda value in the exhaust gas of the internal combustion engine; determining at least one variable from the detected lambda value, characterizing the quality of the gaseous fuel; and controlling the internal combustion engine based on the at least one variable.

An apparatus for mixing fuel and air and providing the mixture to an engine can include an entry conduit, a transfer conduit, and a mounting plate for coupling to an engine. The entry conduit can include a straight channel and an opening for receiving air into the channel. The entry conduit can also include a fuel inlet port disposed through a wall of the entry conduit for receiving fuel into the channel. A venturi valve can be disposed within the straight channel and can include an air-fuel mixing chamber, an inner wall, one or more fuel orifices disposed through the inner wall, and a fuel diffusion chamber fluidicly coupled to the fuel inlet port and the air-fuel mixing chamber. The transfer conduit can be coupled or integrally formed with the entry conduit and include an arcuate internal channel.

A fuel delivery system may be utilized in an internal combustion engine or a generator engine. The fuel delivery system includes a fuel injector and a venturi. The venturi provides a force for delivering the fuel into the manifold of the engine, and the fuel injector provides metering to control the amount of fuel delivered into the manifold of the engine. In one example, the fuel delivery system includes a first chamber configured to enclose a gaseous fuel, a second chamber configured to direct a flow of air through the venturi, and a plunger. The plunger is controlled to selectively connect and disconnect the first chamber and the second chamber to control the flow of the gaseous fuel into the second chamber under a differential pressure of the venturi.

A gas mixer for mixing gaseous fuel and air for an internal combustion engine is disclosed. The gas mixer may have a housing defining an air path for mixing the gaseous fuel and the air within the air path. The housing may have a narrowed portion. The gas mixer may also have a displacement body axially displaceable and coaxially arranged within the air path. The displacement body and the housing may define an air passage disposed at the narrowed portion. The gas mixer may further have a fuel inlet fluidly connected to the air passage. The fuel inlet may be configured to supply gaseous fuel to the air passage. Further, the gas mixer may have an adjusting unit disposed at least partially within the air path. The adjusting unit may be connected to the displacement body and may be configured to axially displace the displacement body.

A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel configured to supplement a primary fuel used by an engine. The electronic valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of the engine. The controller is configured to control the electronic valve such that the electronic valve is (i) closed to prevent the supplemental fuel from being provided to the air supply system in response to the temperature being less than a temperature threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the temperature being greater than the temperature threshold.

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 gas internal combustion engine, having a gas mixer, an intake section and an engine to which a fuel mixture having a charging mixture is fed. The engine is operated in the gas mode with gas as the fuel in the charging mixture. By an input mixture portion, from an earlier mixture state, of a gas/air mixture, an output mixture portion, from a later mixture state, of the gas/air mixture is determined by an intake section model. The output mixture portion is determined at an engine feed, the input mixture portion is determined over a number of intermediate states of the mixture portion in a number of assigned volumes of the intake section. The intake mixture portion of a gas/air mixture is determined at the gas mixer, and an air stream and/or gas stream is set at the gas mixer in accordance with the input mixture portion.

A supplemental fuel system for a machine with an engine is configured to monitor a voltage of a power supply of the machine based on voltage data acquired by a voltage sensor where the power supply is configured to receive power from an alternator driven by the engine, compare the voltage to a voltage threshold, and control an electronic lock off valve positioned between a supplemental fuel tank and an air supply system for the engine such that the electronic lock off valve is (i) closed to prevent a supplemental fuel from being provided from the supplemental fuel tank to the to the air supply system in response to the voltage being less than the voltage threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the voltage being greater than the voltage threshold.