A housing defines a gaseous fuel inlet and a gaseous fuel outlet. A rotor defines an internal flow passage therethrough that rotates with the rotor to, alternately, allow gaseous fuel flow, or to block gaseous fuel flow, between the inlet and the outlet, based on a position of the rotor. A seal is biased to abut an exterior surface of the rotor. The seal is between the rotor and the outlet. An actuator is rotably coupled to the rotor. The driver is configured to rotate the rotor. A controller is in communication with the driver and is configured to control the driver to rotate at a rate based on an engine speed of the engine.

In metal-on-metal sealing structures, the sealing criteria employed for high pressure liquid fuel does not work when sealing gaseous fuels. An improved method for sealing a gaseous fuel between gaseous fuel conduits in an internal combustion engine comprises forming a contact band between two surfaces of a sealing structure between a first conduit and a second conduit. A width of the contact band is at least equal to the larger of a minimum contact pressure width where contact pressure is at least equal to a predetermined minimum contact pressure; and a minimum yield zone width where at least one of the two surfaces have plastically deformed.

In a gas engine provided with a gas supply pipe (35) branching into a supercharger-side gas supply pipe (33) and a cylinder-side gas supply pipe (37), a supercharger-side gas adjusting valve (43) and a cylinder-side gas adjusting valve (45) for controlling flow rates of passages, when the gas concentration of the fuel gas changes, the cylinder-side gas adjusting valve is controlled first to keep the output of the gas engine constant and then the supercharger-side gas adjusting valve is controlled to achieve the fuel gas flow rate Q1 based on the constant flow ratio by means of a gas supply controller (63), while maintaining the flow rate ratio Q1/Q2 at a constant value where Q1 is a fuel gas flow rate in the supercharger-side gas supply pipe and Q2 is a fuel gas flow rate in the cylinder-side gas supply pipe.

A fuel gas feed and ignition apparatus for a gas engine (1) with a combustion chamber includes a number of injection channels (37), a main fuel gas feed line (24) for main fuel gas in which a main fuel gas valve (21) is arranged, and a number of torch channels (52) for hot combustion gas connected to a pre-combustion chamber (15), wherein an ignition fuel supply line (17) leads to the pre-combustion chamber (15) and a pre-combustion chamber valve (18) is arranged in the ignition fuel supply line (17). Control of both the time and the duration and thus also the quantity of the injection of main fuel gas, as well as of ignition fuel for the pre-combustion chamber completely independently of one another and in a precise and, above all, rapid manner is achieved in that both the main fuel gas valve (21) and the pre-combustion chamber valve (18) are embodied as an electrically-actuated, electronically-controlled valve.

A gas engine 1 which operates in stoichiometric mode under high-load conditions and which operates in lean burn mode under medium- and low-load conditions includes a valve 2 which supplies the gas engine 1 with an air-fuel mixture composed of air and fuel gas. In the valve 2, a valve unit 21 for stoichiometric operation is connected in series to a valve unit 22 for lean burn operation and is also connected to a mixer 24. An opening area of the valve 2 is controlled in such a manner as to ensure a predetermined opening area for effecting stoichiometric operation, to uniformly decrease the opening area over time until a switching operation from stoichiometric operation to lean burn operation ends, to ensure a predetermined opening area for effecting lean burn operation, and to uniformly increase the opening area over time until a switching operation from lean burn operation to stoichiometric operation ends.

Provided is a liquefied gas treatment system for a vessel, which includes a cargo tank storing liquefied natural gas (LNG), and an engine using the LNG as fuel. The liquefied gas treatment system includes: a compressor line configured to compress boil-off gas (BOG) generated in the cargo tank by a compressor and supply the compressed BOG to the engine as fuel; a high pressure pump line configured to compress the LNG stored in the cargo tank by a pump and supply the compressed LNG to the engine as fuel; and a heat exchanger configured to liquefy a part of BOG, which is compressed by the compressor, by exchanging heat with BOG that is discharged from the cargo tank and transferred to the compressor.

A nozzle for a prechamber assembly of an engine includes a nozzle body. The nozzle body is hollow and includes an outer surface and an inner surface. The outer surface defines an outer opening, and the inner surface defines an interior chamber and an inner opening. The nozzle body includes an orifice surface which defines an orifice passage extending between, and in communication with, the outer and inner openings. The orifice passage is in communication with the interior chamber via the inner opening. The orifice surface is continuously curved. The inner surface of the nozzle body can include a groove surface that is contiguous with the orifice surface. The groove surface defines an orifice groove in communication with the interior chamber and with the orifice passage.

In certain embodiments, a unique method and pre-combustion chamber (PCC) structure may ensure very efficient flame propagation of lean fuel-air mixture in natural gas engines by reducing the amount of fuel admitted to the PCC. A PCC may include an enclosed volume of 1-3% of the main combustion chamber volume, with a spark plug and a fuel passage located opposite one or more PCC discharge nozzles to create a relatively richer fuel-air mixture with relatively lower turbulence in the spark plug region and a relatively leaner fuel-air mixture with relatively high turbulence in the nozzle region, which can be reliably and efficiently ignited, resulting in a high velocity flame jet/torch emerging from the prechamber into the main chamber. The PCC may be threaded with a 22 mm×1.5 or ⅞″-18 thread size, to allow the PCC to be screwed into a cylinder head in place of a spark plug.

A mixing block to supply a throttle-able hydrogen and air mixture to an internal combustion engine includes a bore through the mixing block between an air intake side and an engine intake side. A slider chamber is disposed orthogonal to and intersecting the bore, where the slider chamber houses a movable slider biased to at least partially block the bore but throttle-able to overcome the bias and reduce blockage of the bore. A jet chamber is disposed parallel to and intersecting the slider chamber and extending away from the slider chamber a distance sufficient to accommodate a shaped needle, where the needle is connected to the slider on one side such that the needle moves within the jet chamber as the slider moves in the slider chamber.

An object is to improve a trap effect to trap ignition fuel gas supplied to a pre-combustion chamber and reduce an amount of non-combusted ignition fuel gas flowing out of the pre-combustion chamber to suppress a decrease in combustion efficiency. A pre-combustion-chamber type gas engine includes: a pre-combustion chamber Sr disposed on a cylinder head portion 10; a spark plug 20 disposed on an upper part of the pre-combustion chamber Sr; a pre-combustion-chamber gas supply mechanism configured to supply ignition fuel gas “g” to the pre-combustion chamber Sr via gas supply channels for the pre-combustion chamber 22a and 22b with an opening on an upper part of the pre-combustion chamber Sr; and a check valve 24 disposed in the gas supply channel 22b for the pre-combustion chamber. The opening of the gas supply channel 22a for the pre-combustion chamber is disposed on a lower surface of a cover member 16 forming the pre-combustion chamber Sr or on an upper section of a side wall of a pre-combustion-chamber member 14, the opening facing in a tangent direction of a side-wall inner peripheral surface 14a of the pre-combustion-chamber member 14. The ignition fuel gas “g” supplied to the pre-combustion chamber Sr forms a swirl flow s1 which swirls about a longitudinal axis x of the pre-combustion chamber Sr inside the pre-combustion chamber Sr.