Abstract: In certain embodiments, remarkable improvements in H2-ICE performance may be achieved with the combination of Active Scavenge Prechamber technology and Predictive Model-Based Spark Control to overcome the drawbacks of known combustion technologies. In certain embodiments, advanced combustion modeling and simulations of the ignition process including the spark event, the arc-travel and stretching, and resulting flame propagation may be used to predict the relationship between the spark energy/power, the flow within the electrode gap, and the flame development (SOC) for different engines, different spark plugs and at various conditions. This information may be used to adjust the spark energy/power characteristic during the same cycle spark event, to minimize the SOC variations and to significantly reduce the propensity to combustion anomalies, such as backfire, knock and preignition, that prevent achieving high engine power densities and efficiencies.

Abstract: In certain embodiments, Lube Oil Controlled Ignition (LOCI) Engine Combustion overcomes the drawbacks of known combustion technologies. First, lubricating oil is already part of any combustion engine; hence, there is no need to carry a secondary fuel and to have to depend on an additional fuel system as in the case of dual-fuel technologies. Second, the ignition and the start of combustion rely on the controlled autoignition of the lubricating oil preventing the occurrence of abnormal combustion as experienced with the Spark Ignition technology. Third, LOCI combustion is characterized by the traveling of a premixed flame; hence, it has a controllable duration resulting in a wide engine load-speed window unlike the Homogeneous Charge Compression Ignition technology where the engine load-speed window is narrow. Adaptive Intake Valve Closure may be used to control in-cylinder compression temperature to be high enough to realize the consistent auto ignition of the lubricating oil mist.

Abstract: In certain embodiments, Lube Oil Controlled Ignition (LOCI) Engine Combustion overcomes the drawbacks of known combustion technologies. First, lubricating oil is already part of any combustion engine; hence, there is no need to carry a secondary fuel and to have to depend on an additional fuel system as in the case of dual-fuel technologies. Second, the ignition and the start of combustion rely on the controlled autoignition of the lubricating oil preventing the occurrence of abnormal combustion as experienced with the Spark Ignition technology. Third, LOCI combustion is characterized by the traveling of a premixed flame; hence, it has a controllable duration resulting in a wide engine load-speed window unlike the Homogeneous Charge Compression Ignition technology where the engine load-speed window is narrow. Adaptive Intake Valve Closure may be used to control in-cylinder compression temperature to be high enough to realize the consistent auto ignition of the lubricating oil mist.

Abstract: In certain embodiments, a time-varying spark current ignition system can be applied to improve spark plug ignitability performance and durability as compared to conventional spark ignition systems. Two performance parameters of interest are spark plug life (durability) and spark plug ignitability. In certain embodiments, spark plug life can be extended by applying a spark current amplitude as low as possible without causing quenching of the flame kernel while it is traveling within an electrode gap and/or by applying spark current of a long enough duration to allow the spark/flame kernel to clear a spark plug gap. In certain embodiments, ignitability can be improved by applying a high enough spark current amplitude to sustain the flame kernel once outside the spark plug gap and/or by applying a spark current for long enough to sustain the flame kernel once outside the spark plug gap.

Abstract: 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 ??-18 thread size, to allow the PCC to be screwed into a cylinder head in place of a spark plug.

Abstract: In certain embodiments, a two-stage precombustion chamber may be used to reduce engine NOx levels, with fueled precombustion chambers, while maintaining comparable engine power output and thermal efficiency. One or more fuel admission points may be located in either the first prechamber stage or the second prechamber stage. A more efficient overall combustion characterized by low levels of NOx formation may be achieved by a two-stage precombustion chamber system while generating very high energy flame jets emerging from the second prechamber stage into the main combustion chamber. A first prechamber stage may be substantially smaller than a second prechamber stage.

Abstract: In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

Abstract: In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

Abstract: Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

Abstract: Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

Abstract: In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

Abstract: Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

Abstract: A prechamber spark plug may have a prechamber having a pre-determined aspect ratio and hole pattern to achieve particular combustion performance characteristics. The aspect ratio and hole pattern may induce a rotational flow of fuel-air in-filling streams inside the prechamber volume. The rotational flow of the fuel-air mixture may include both radial flow and axial flow characteristics based on the aspect ratio and hole pattern. Axial flow characteristics can include a first axial direction proximate the periphery of the rotational flow and a counter second axial direction approaching the center of the rotational flow. The radial and axial flow characteristics may further include radial air-fuel ratio stratification and/or axial air-fuel ratio stratification. The rotational flow, the radial flow and the axial flow may be adjusted by alteration of the aspect ratio and hole pattern to achieve particular combustion performance characteristics in relation to a wide variety of spark gap geometries.

Abstract: A prechamber spark plug may have a prechamber having a pre-determined aspect ratio and hole pattern to achieve particular combustion performance characteristics. The aspect ratio and hole pattern may induce a rotational flow of fuel-air in-filling streams inside the prechamber volume. The rotational flow of the fuel-air mixture may include both radial flow and axial flow characteristics based on the aspect ratio and hole pattern. Axial flow characteristics can include a first axial direction proximate the periphery of the rotational flow and a counter second axial direction approaching the center of the rotational flow. The radial and axial flow characteristics may further include radial air-fuel ratio stratification and/or axial air-fuel ratio stratification. The rotational flow, the radial flow and the axial flow may be adjusted by alteration of the aspect ratio and hole pattern to achieve particular combustion performance characteristics in relation to a wide variety of spark gap geometries.

Abstract: A prechamber spark plug may have a prechamber having a pre-determined aspect ratio and hole pattern to achieve particular combustion performance characteristics. The aspect ratio and hole pattern may induce a rotational flow of fuel-air in-filling streams inside the prechamber volume. The rotational flow of the fuel-air mixture may include both radial flow and axial flow characteristics based on the aspect ratio and hole pattern. Axial flow characteristics can include a first axial direction proximate the periphery of the rotational flow and a counter second axial direction approaching the center of the rotational flow. The radial and axial flow characteristics may further include radial air-fuel ratio stratification and/or axial air-fuel ratio stratification. The rotational flow, the radial flow and the axial flow may be adjusted by alteration of the aspect ratio and hole pattern to achieve particular combustion performance characteristics in relation to a wide variety of spark gap geometries.

Abstract: In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

Abstract: Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

Abstract: In certain embodiments, a time-varying spark current ignition system can be applied to improve spark plug ignitability performance and durability as compared to conventional spark ignition systems. Two performance parameters of interest are spark plug life (durability) and spark plug ignitability. In certain embodiments, spark plug life can be extended by applying a spark current amplitude as low as possible without causing quenching of the flame kernel while it is traveling within an electrode gap and/or by applying spark current of a long enough duration to allow the spark/flame kernel to clear a spark plug gap. In certain embodiments, ignitability can be improved by applying a high enough spark current amplitude to sustain the flame kernel once outside the spark plug gap and/or by applying a spark current for long enough to sustain the flame kernel once outside the spark plug gap.

Abstract: A prechamber spark plug may have a prechamber having a pre-determined aspect ratio and hole pattern to achieve particular combustion performance characteristics. The aspect ratio and hole pattern may induce a rotational flow of fuel-air in-filling streams inside the prechamber volume. The rotational flow of the fuel-air mixture may include both radial flow and axial flow characteristics based on the aspect ratio and hole pattern. Axial flow characteristics can include a first axial direction proximate the periphery of the rotational flow and a counter second axial direction approaching the center of the rotational flow. The radial and axial flow characteristics may further include radial air-fuel ratio stratification and/or axial air-fuel ratio stratification. The rotational flow, the radial flow and the axial flow may be adjusted by alteration of the aspect ratio and hole pattern to achieve particular combustion performance characteristics in relation to a wide variety of spark gap geometries.