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US 11,643,985 B2Granted
Optimized fuel management system for direct injection ethanol enhancement of gasoline engines
AssigneeMassachusetts Institute of Technology
InventorsLeslie Bromberg, Daniel R. Cohn, John B. Heywood
Life of this patent
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Abstract
Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.
Claims20
A fuel management system for a spark ignition engine, comprising:
- at least one direct injector;
- at least one port injector;
- and
- an electronic control unit configured to control use of the at least one direct injector and the at least one port injector,
- wherein the fuel management system is configured to use both the at least one direct injector and the at least one port injector to introduce a mixture of ethanol with gasoline into a spark ignition engine during at least a part of a drive cycle,
- wherein both the at least one direct injector and the at least one port injector are configured to operate at a highest torque value at which the spark ignition engine is operable at different speeds during the drive cycle,
- wherein the fuel management system is further configured such that the at least one direct injector provides an octane enhancement relative to the at least one port injector in the spark ignition engine due to evaporative cooling from direct injection by the at least one direct injector,
- wherein the fuel management system is further configured to provide a stoichiometric or substantially stoichiometric air/fuel ratio in the spark ignition engine in at least a part of the part of the drive cycle in which both the at least one direct injector and the at least one port injector introduce the mixture of ethanol with gasoline into the spark ignition engine,
- wherein the fuel management system is further configured such that the at least one direct injector is inoperable to provide direct injection of the mixture of ethanol with gasoline when torque decreases below a selected value, the selected value being dependent on engine speed,
- wherein the fuel management system is further configured to prevent undesired autoignition of end gas in at least one cylinder in the spark ignition engine.
7 more elements
A fuel management system for a spark ignition engine, comprising:
- at least one direct injector;
- at least one port injector;
- and
- an electronic control unit configured to control use of the at least one direct injector and the at least one port injector,
- wherein the fuel management system is configured to use both the at least one direct injector and the at least one port injector to introduce a mixture of ethanol with gasoline into a spark ignition engine during at least a part of a drive cycle,
- wherein both the at least one direct injector and the at least one port injector are configured to operate at a highest torque value at which the spark ignition engine is operable at different speeds,
- wherein the fuel management system is further configured such that the at least one direct injector provides an octane enhancement relative to the at least one port injector in the spark ignition engine due to evaporative cooling from direct injection by the at least one direct injector,
- wherein the fuel management system is further configured to provide a stoichiometric or substantially stoichiometric air/fuel ratio in the spark ignition engine in at least a part of the part of the drive cycle in which the at least one direct injector and the at least one port injector introduce the mixture of ethanol with gasoline into the spark ignition engine,
- wherein the fuel management system is further configured such that the at least one direct injector is inoperable to provide direct injection of the mixture of ethanol with gasoline when torque decreases below a selected value,
- wherein the fuel management system is further configured to determine the selected value of torque by employing at least one of open loop control or closed loop control,
- wherein the fuel management system is further configured to prevent undesired autoignition of end gas in at least one cylinder in the spark ignition engine, and
- wherein the fuel management system is further configured to directly inject at least part of the mixture of ethanol with gasoline into the spark ignition engine after one or more inlet valves of the spark ignition engine is closed.
9 more elements
A fuel management system for a spark ignition engine, comprising:
- at least one direct injector;
- at least one port injector;
- and
- an electronic control unit configured to control use of the at least one direct injector and the at least one port injector,
- wherein the fuel management system is configured to use both the at least one direct injector and the at least one port injector to introduce a mixture of ethanol with gasoline into a spark ignition engine during at least a part of a drive cycle,
- wherein both the at least one direct injector and the at least one port injector are configured to operate at a highest torque value at which the spark ignition engine is operable at different speeds,
- wherein the fuel management system is further configured such that the at least one direct injector provides an octane enhancement relative to the at least one port injector in the spark ignition engine due to evaporative cooling from direct injection by the at least one direct injector,
- wherein the fuel management system is further configured to provide a stoichiometric or substantially stoichiometric air/fuel ratio in the spark ignition engine in at least a part of the part of the drive cycle in which the at least one direct injector and the at least one port injector introduce the mixture of ethanol with gasoline into the spark ignition engine,
- wherein the fuel management system is further configured such that the at least one direct injector is inoperable to provide direct injection of the mixture of ethanol with gasoline when torque decreases below a selected value,
- wherein the fuel management system is further configured to determine the selected value of torque by employing open loop control,
- wherein the fuel management system is further configured to prevent undesired autoignition of end gas in at least one cylinder in the spark ignition engine, and
- wherein the fuel management system is further configured to employ both open loop control and closed loop control, the closed loop control using a knock detector, to prevent undesired autoignition of end gas in at least one cylinder in the spark ignition engine at a time in the drive cycle when torque varies.
9 more elements
Dependencies are inferred from the claim text.