A controller for an internal combustion engine includes processing circuitry. The processing circuitry is configured to execute an estimation process that estimates a density parameter of fuel in an upper layer portion of a delivery pipe and a density parameter of fuel in a lower layer portion of the delivery pipe and an operation process that includes acquiring a density parameter of the fuel injected from a fuel injection valve and operating an operation unit of the internal combustion engine based on the acquired density parameter. The estimation process includes a process that assumes that when the density of the fuel flowing into the delivery pipe is high, a greater proportion of the fuel flowing into the delivery pipe flows into the lower layer portion than when the density of the fuel flowing into the delivery pipe is low.

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.

A blended fuel injection control method may include a cold-starting determination step in which a controller determines whether a cold-starting condition is satisfied on the basis of output values that can be obtained by a vehicle; a detection step in which the controller detects the content of ethanol in blended fuel of gasoline and ethanol when determining the cold-starting condition is satisfied; and a first injection control step in which the controller controls the blended fuel to be injected selectively in one of a Multi-Point Injection (MPI) mode, an MPI & GDI mode combining MPI and Gasoline Direct Injection (GDI) modes, and a GDI mode in accordance with the content of ethanol in the blended fuel until an engine RPM reaches an early peak RPM in engine-cranking.

According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of passing a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.

An engine/reformer system accepts a first fuel and reforms it into syngas for use as a fuel in an accompanying internal combustion engine. Prior to reforming, the first fuel is pressurized and/or heated to at or near supercritical fluid conditions, such that the resulting syngas leaves the reformer in a supercritical fluid state. Injection of the supercritical syngas into an engine cylinder avoids the autoignition problems that occur when gaseous syngas is used. The first fuel is a fully self-reforming fuel (one that needs no separate water supply for complete conversion to syngas), and can beneficially be a wet fuel, such as ethanol containing water, allowing the system to use intermediate products of an ethanol production process (such as hydrous ethanol and stillage wastewater) as fuel, and reducing the overall cost of fuel production and engine operation.

A mixed fuel amount control system applying active purging includes: a fuel tank in which biofuel and fossil fuel are mixed and stored, an active purging device to supply an evaporated gas evaporated in the fuel tank to an intake pipe, and a concentration sensor to sense a mixing ratio of the biofuel stored in the fuel tank changes. In particular, the flow rate and the concentration of the evaporated gas of the fuel tank flowing into the intake pipe are changed according to a mixing ratio of biofuel and fossil fuel.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.

Disclosed are a method and system for controlling fuel injection in response to a change in the content of ethanol in a FFV having oxygen sensors and an ethanol sensor. The system includes an ethanol content change detection unit configured to detect a change in the content of ethanol, a flow rate calculation unit configured to calculate a volumetric flow rate of blending fuel and to integrate the calculated value, a condition determination unit configured to determine whether the change in the content of ethanol satisfies a condition for applying a fuel injection correction value, a control execution determination unit configured to determine whether to apply the fuel injection correction value by comparing the volumetric flow rate integration value with a preset second reference value, and a controller configured to determine a fuel injection correction value and to adjust an amount of fuel injection.

The present invention relates to a diagnosis method for an ethanol sensor of a flexible fuel vehicle, the diagnosis method including: a) the fuel refilling detection step of detecting whether fuel is filled to a fuel tank; b) the maximum changeable content range calculation step of calculating a content range of ethanol in the fuel stored in the fuel tank; c) the ethanol sensor value acquirement step of determining whether the data detected from an ethanol sensor converges into a given value; d) the oxygen sensor value acquirement step of determining whether the data detected from an oxygen sensor converges into a given value; and e) the ethanol sensor abnormality determination step of determining that an error is generated from the ethanol sensor if the data acquired at the ethanol sensor value acquirement step or the data acquired at the step is not a value in the calculated range.