A hydrogen engine in which hydrogen gas is supplied into a combustion chamber as fuel, comprises: an injector for injecting hydrogen gas; a pressure accumulation chamber communicating with an injection hole of the injector; a communication hole communicating with the pressure accumulation chamber and the combustion chamber; and a pressure accumulation chamber defining portion provided between the injector and the combustion chamber and defining the pressure accumulation chamber and the communication hole. The pressure accumulation chamber defining portion is formed separately from the injector and has a thermal conductivity equal to or higher than a thermal conductivity of a combustion chamber wall defining the combustion chamber.

An engine has, for each cylinder, a combustion chamber and a combustion pre-chamber communicating with the combustion chamber. First and second spark plugs are associated with the pre-chamber and combustion chamber, respectively. Gasoline is injected by an injector device directly into the combustion chamber and/or by an injector device into a cylinder intake duct. There is no device for injecting gasoline, air or an air/gasoline mixture directly into the pre-chamber. The engine operates with an air/gasoline mixture substantially corresponding to stoichiometric for compatibility with an exhaust system having a trivalent catalyst. The pre-chamber is, not used for engine operation with poor dosing, but to increase resistance to engine detonation. The engine can thus be configured with a high compression ratio, with a significant reduction in fuel consumption at the same power level. The second spark plug is only activated at low and medium engine loads to stabilize combustion.

A pre-chamber body for an internal combustion engine is disclosed. The pre-chamber body may have a pre-chamber. The pre-chamber body may also have a flow transfer passage, which may fluidly connect the pre-chamber and an exterior of the pre-chamber body. In addition, the pre-chamber body may have at least one backflow channel, which may fluidly connect the pre-chamber and the flow transfer passage.

A pre-chamber body for an engine is disclosed. The pre-chamber body may have a pre-chamber. The pre-chamber body may also have flow transfer channels fluidly connecting the pre-chamber and an exterior of the pre-chamber body. Each flow transfer channel extends along a flow transfer channel axis (B) from an inner opening via a throat section to an outer opening. A cross-section of the flow transfer channels converges from a first cross section (A.sub.1) of the inner opening to a second cross-section (A.sub.2) of the throat section and diverges from the second cross-section (A.sub.2) to a third cross-section (A.sub.3) of the outer opening along the flow transfer channel axis (B). At least one of the inner opening and the outer opening has an oval shape with a maximum diameter (a.sub.1, a.sub.3) and a minimum diameter (b.sub.1, b.sub.3), the maximum diameter (a.sub.1, a.sub.3) being greater than the minimum diameter (b.sub.1, b.sub.3).

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 mm1.5 or -18 thread size, to allow the PCC to be screwed into a cylinder head in place of a spark plug.

An internal combustion engine 10 comprises a spark plug 70 which has a spark generation part 71, and a partition wall part 80. The partition wall part 80 partitions a combustion chamber CC into a main combustion chamber CM and an ignition chamber CI. The combustion chamber is defined by a cylinder bore wall 21, a piston crown surface part 31 and a cylinder head wall 41. The cylinder bore wall and the piston crown surface part are exposed to the main combustion chamber, and the spark generation part is exposed to the ignition chamber. A through hole 81 and a through hole 82 are formed in the partition wall part such that the main combustion chamber and the ignition chamber are in communication with each other. Flame is generated in the ignition chamber when combustion of fuel-air mixture is started by a spark generated from the spark generation part in the ignition chamber. The flame is ejected from the ignition chamber into the main combustion chamber through the first and second through holes. Distance between the first through hole and the cylinder bore wall is longer than distance between the second through hole and the cylinder bore wall. The first and second through holes are formed such that penetration of the flame ejected from the first through hole is larger than penetration of the flame ejected from the second through hole.

A method for operating an internal combustion engine includes operating at least one cylinder pre-chamber in a homogeneous charge compression ignition (HCCI) combustion mode by providing an air/fuel mixture in the pre-chamber that is fluidly connected to the at least one engine cylinder, creating H and OH radicals in the pre-chamber to achieve an ignition in the at least one pre-chamber, determining whether an ignition timing is advanced or delayed relative to a desired timing, and delaying the ignition when the ignition is advanced relative to the desired timing by cooling the pre-chamber and the at least one engine cylinder.

A pre-chamber gas valve including a valve body, at least one valve spring and at least one valve needle, wherein the valve body has a lower space which is acted upon with gas in the operating condition and an upper space in which the valve spring is arranged, wherein the upper space is closed by way of a pressed plug.

Systems are provided for cooling combustion chamber gasses and increasing an amount of air entrained in an injected fuel spray. In one example, a cooling passage may be included in an internal combustion engine, the cooling passage positioned exterior to a cylinder bore of the engine and coupled to the cylinder bore at a first opening and a second opening. The cooling passage may receive gasses from the cylinder bore via the first opening, and may cool the gasses as they travel through the cooling passage before returning the gasses to the cylinder bore via the second opening.

A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.