US 7,740,004 B2 · Fuel management system for variable ethanol octane enhancement of gasoline engines

Abstract

Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Claims25

Dependent claims

A turbocharged or supercharged spark ignition engine system which uses both port fuel injection of gasoline from a first source and direct fuel injection of an anti-knock agent that is a fuel from a second source comprising:

a spark ignition engine;
a turbocharger or supercharger;
means for port fuel injection of gasoline from the first source;
means for direct fuel injection of a liquid anti-knock agent that is a fuel from the second source;
wherein during part of the engine operating time, the engine is fueled both by gasoline that is port fuel injected and the anti-knock agent that is directly injected;
and
a fuel management system which increases the relative amount of anti-knock agent in the engine with increasing torque so as to prevent knock
where the fuel management system uses closed loop control to control the amount of directly injected anti-knock agent and employs information from a knock detector;
and
where the engine is operated with a substantially stoichiometric fuel/air ratio.

7 more elements

a spark ignition engine;
a turbocharger or supercharger;
means for port fuel injection of gasoline from the first source;
means for direct fuel injection of a liquid anti-knock agent that is a fuel from the second source;
wherein during part of the engine operating time, the engine is fueled both by gasoline that is port fuel injected and the anti-knock agent that is directly injected;
and
a fuel management system which increases the relative amount of anti-knock agent in the engine with increasing torque so as to prevent knock;
where the fuel management system uses closed loop control to control the amount of directly injected anti-knock agent that is used and employs information from a knock detector;
and
where the engine is operated with a substantially stoichiometric fuel/air ratio;
and wherein engine downsizing is used to obtain a higher efficiency than a larger engine that uses port fuel injection of gasoline alone and produces the same maximum horsepower.

8 more elements

A turbocharged or supercharged spark ignition engine system which uses both port fuel injection of gasoline from a first source and direct fuel injection of a liquid anti-knock agent that is a fuel from a second source comprising:

a spark ignition engine;
a turbocharger or supercharger;
means for fueling the engine with gasoline from the first source;
means for direct fuel injection of the liquid anti-knock agent that is a fuel from the second source;
wherein during part of the engine operating time, the engine is fueled both by gasoline and by the anti-knock agent that is directly injected;
and
a fuel management system which increases the relative amount of anti-knock agent in the engine with increasing torque so as to prevent knock;
where the fuel management system uses closed loop control to control the amount of directly injected anti-knock agent that is used and employs information from a knock detector;
and
where the engine is operated with a substantially stoichiometric fuel/air ratio;
and
wherein engine downsizing is used to obtain a higher efficiency than a larger engine that uses port fuel injection of gasoline alone and produces the same maximum horsepower.

9 more elements

Dependencies are inferred from the claim text.

Fuel management system for variable ethanol octane enhancement of gasoline engines

Life of this patent

Fuel management system for variable ethanol octane enhancement of gasoline engines

Life of this patent

Abstract

Claims25