Alcohol And Plasma Enhanced Prechambers For Higher Efficiency, Lower Emissions Gasoline Engines
AssigneeMassachusetts Institute of Technology
InventorsLeslie Bromberg, Daniel R. Cohn
Life of this patent
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Abstract
Optimized alcohol and plasma enhanced prechambers for engines powered by gasoline and other fuels are used to increase the range of prechamber operation and to reduce soot. The increased prechamber capability is employed to extend the limit of lean operation of the engines. It can also be used to extend the limit of heavy EGR operation and to enable higher RPM operation. The amount of alcohol used in the prechamber is preferably less than 2% of the fuel that is used in the engine cylinder. The alcohol for the prechamber can be entirely provided by onboard separation from a gasoline-alcohol fuel mixture.
Claims29
An engine that uses a prechamber to ignite a fuel air mixture in at least one cylinder wherein the prechamber is fueled with alcohol or with an alcohol-gasoline mixture;
- wherein the alcohol or alcohol-gasoline mixture is directly injected into the prechamber;
- wherein an equivalence ratio in the prechamber is adjusted based on information that includes at least one of engine speed or engine torque;
- and
- wherein the alcohol is ethanol or methanol.
An engine that uses a prechamber to ignite a fuel air mixture in at least one cylinder wherein the prechamber is fueled with alcohol alone or with an alcohol-gasoline mixture;
- wherein the alcohol or alcohol-gasoline mixture is directly injected into the prechamber;
- and
- wherein an equivalence ratio in the prechamber is adjusted based on information that includes at least one of engine speed or engine torque;
- wherein the alcohol is ethanol or methanol;
- wherein fuel used in the at least one cylinder is different from the alcohol or alcohol-gasoline mixture that is used in the prechamber;
- and
- wherein lambda for the fuel air mixture in the cylinder is 2.0 or greater.
An engine that uses a prechamber to ignite a fuel air mixture in at least one cylinder where the prechamber is fueled with alcohol alone or with an alcohol-gasoline mixture;
- wherein the alcohol or alcohol-gasoline mixture is directly injected into the prechamber;
- wherein the alcohol is ethanol or methanol;
- wherein an equivalence ratio in the prechamber is adjusted based on information that includes at least one of engine speed or engine torque;
- wherein the fuel in the at least one cylinder is different from the alcohol or alcohol-gasoline mixture that is used in the prechamber;
- wherein the engine is operated with a stoichiometric fuel air ratio and NOx from engine exhaust is reduced by use of a three way catalyst;
- and
- wherein the use of the prechamber enables increased dilution to be used in the at least one cylinder.
Dependencies are inferred from the claim text.