A system composed of a water sleeve and a spark plug for an internal combustion engine. The spark plug has a supply passage, a center conductor, an insulator surrounding the center conductor, and a metallic body surrounding the insulator. A center electrode and at least one ground electrode form a spark air gap. In the region of its front end, the spark plug has an external thread for screwing the spark plug into a component of the internal combustion engine and has at least one discharge opening of the supply passage. The spark plug, at its front end, has, attached to the body, a sleeve that contains the external thread; the body has, on its outside, at least one groove that forms a section of the supply passage; and the sleeve has a heat conducting section that contains at least a part of the external thread and that is in contact with the body and covers at least portions of the groove.

A fuel pump assembly for pressurizing fuel such as dimethyl ether (DME). The fuel pump assembly includes a plunger assembly and a pump block defining a pumping chamber and a plunger assembly cavity in communication with the pumping chamber. The plunger assembly is movable at least partially in the plunger assembly cavity towards and from the pumping chamber. The fuel pump assembly includes a metering valve and a suction channel located between the metering valve and the pumping chamber in an intended direction of flow of the fuel, wherein the fuel pump assembly comprises a leakage return conduit, with a first leakage return conduit opening in fluid communication with said plunger assembly cavity, adapted to return fuel that has leaked from the pumping chamber. The leakage return conduit includes a second leakage return conduit opening located in the suction channel.

A fuel injection device that injects a liquefied gas fuel from an injection port to a combustion chamber of the internal combustion engine includes a passage forming member configured to define a fuel passage through which the liquefied gas fuel flows to the injection port, a temperature regulating unit configured to adjust a temperature of the liquefied gas fuel flowing through the fuel passage according to an operation state of the internal combustion engine, and a pressure regulating unit configured to adjust a pressure of the liquefied gas fuel flowing through the fuel passage according to the operation state of the internal combustion engine.

A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a voltage 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 voltage sensor is configured to acquire voltage data from a power supply indicative of a voltage of the power supply. The power supply is configured to receive power from an alternator driven by the engine. The controller is configured to control the electronic valve such that the electronic valve is closed in response to the voltage being less than a voltage threshold indicating that the engine is not operating and open/openable in response to the voltage being greater than the voltage threshold indicating that the engine is operating.

A supplemental fuel system includes a fuel mixer having a nozzle and a stem. The nozzle is configured to be positioned within a conduit of an air supply system for an engine. The nozzle has a body defining a first inlet, an outlet, a passage extending from the first inlet to the outlet, and a second inlet positioned between the first inlet and the outlet. The body has a first cross-sectional dimension that is configured to be less than a second cross-sectional dimension of the conduit such that (i) a first portion of air flowing through the conduit flows through the passage and (ii) a second portion of the air flowing through the conduit flows around the nozzle. The stem has a first end that interfaces with the second inlet. The stem is configured to extend through a wall of the conduit.

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.

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 fuel system for a bi-fuel vehicle, which is provided with an engine and an LPG tank connected to each other through a fuel supply line and a fuel return line through which liquefied petroleum gas (LPG) fuel passes, includes: a 3-way valve which is installed in the fuel return line, and selectively opened and closed to move returning LPG fuel to a canister connected with a fuel tank; and a return tube, which branches off from the fuel return line, installed so that the returning LPG fuel passes through the canister in accordance with an operation of the 3-way valve, allowing the LPG fuel of which the temperature is decreased by heat exchange while the LPG fuel passes through the canister to move to the fuel return line.

A mixer for separate streams of gas includes a center stream of a first gas and a co-axial stream of a second gas injected at an angle to the center stream and filling an annulus around the center stream. The mixer may further include a feed zone wherein the first gas is introduced into the mixer as the center stream and the second gas is introduced into the mixer as the co-axial stream filling the annulus around the center stream; a mixing zone wherein the first gas and the second gas mix with no recirculation zones to form a mixture; and a diffusion zone for advancing the mixture from the mixing zone. Corresponding or associated methods for mixing materials are also provided.

A reserve fuel system can be used to supplement fuel provided to an engine of wellsite equipment. For example, a fuel supply line can transport gaseous fuel at a wellsite to an engine of an equipment coupled to the fuel supply line. A reserve fuel tank can store gaseous fuel diverted from the fuel supply line. The reserve fuel tank can include a first valve coupling a first end of the reserve fuel tank to the fuel supply line to divert the gaseous fuel and a second valve coupling a second end of the reserve fuel tank to the engine. The second valve can be in a closed position to prevent the stored gaseous fuel from transferring to the engine or an open position to transfer the stored gaseous fuel to the engine. A control system can adjust the second valve based on a pressure of the fuel supply line.