The present invention relates to a method for controlling injection of a gaseous fuel, such as hydrogen or a hydrogen based gas, and a water-based fluid medium into a combustion engine. The method comprises the steps of: in a first operational mode injecting the gaseous fuel and optionally a water based fluid medium into a combustion chamber of the engine at a relatively high pressure; in a second operational mode injecting water as liquid into engine to reduce the temperature and pressure inside the combustion chamber, and injecting the gaseous fuel into the combustion chamber at a relatively low pressure.

The present invention relates to a method for controlling injection of a gaseous fuel, such as hydrogen or a hydrogen based gas, and a water-based fluid medium into a combustion engine. The method comprises the steps of: in a first operational mode injecting the gaseous fuel and optionally a water based fluid medium into a combustion chamber of the engine at a relatively high pressure; in a second operational mode injecting water as liquid into engine to reduce the temperature and pressure inside the combustion chamber, and injecting the gaseous fuel into the combustion chamber at a relatively low pressure.

Methods and systems are provided for improving engine knock control by accounting for a drop in charge cooling efficiency of a knock control fluid at higher temperatures. In response to the prediction of an elevated temperature of a knock control fluid at a time of release from a direct injector, a pulse width of the injection is adjusted. Any knock relief deficits are compensated for using alternate engine adjustments, such as boost or spark timing adjustments.

Methods and systems are provided for improving engine knock control by accounting for a drop in charge cooling efficiency of a knock control fluid at higher temperatures. In response to the prediction of an elevated temperature of a knock control fluid at a time of release from a direct injector, a pulse width of the injection is adjusted. Any knock relief deficits are compensated for using alternate engine adjustments, such as boost or spark timing adjustments.

Spark ignition engine operation at higher RPM so as to reduce alcohol requirements in high efficiency alcohol enhanced gasoline engines is disclosed. Control of engine upspeeding (use of a higher ratio of engine RPM to wheel RPM) so as to achieve an alcohol reduction objective while limiting any decrease in efficiency is described. High RPM alcohol enhanced gasoline engine operation in plug-in series hybrid powertrains for heavy duty trucks and other vehicles is also described.

Spark ignition engine operation at higher RPM so as to reduce alcohol requirements in high efficiency alcohol enhanced gasoline engines is disclosed. Control of engine upspeeding (use of a higher ratio of engine RPM to wheel RPM) so as to achieve an alcohol reduction objective while limiting any decrease in efficiency is described. High RPM alcohol enhanced gasoline engine operation in plug-in series hybrid powertrains for heavy duty trucks and other vehicles is also described.

A control system for an internal combustion engine is provided with a combustion control part, an operating state judging part judging if an engine operating state is a steady state or a combustion noise is a noise transition state where the combustion noise increases over a predetermined allowable noise value when burning fuel by an ignition-assist self-ignition combustion, and an ozone supply control part controlling the amount of ozone supplied to the combustion chamber by the ozone supply system. The ozone supply control part controls the amount of supply of ozone to a predetermined reference amount when the state is judged to be the steady state and controls the amount of supply of ozone to an amount of supply smaller than the reference amount or makes the amount of supply of ozone zero when the state is judged to be the noise transition state.

A method for operating an engine, comprising port injecting a first quantity of a first gaseous fuel in a cylinder cycle and direct injecting a second quantity of a secondary injectant in the cylinder cycle as a function of a desired air-to-fuel ratio (AFR), the desired AFR based on a temperature of an engine cylinder valve. The desired AFR may be outside the AFR range available during natural gas combustion alone and thus allows for cooler engine operation.

A method for operating an engine, comprising port injecting a first quantity of a first gaseous fuel in a cylinder cycle and direct injecting a second quantity of a secondary injectant in the cylinder cycle as a function of a desired air-to-fuel ratio (AFR), the desired AFR based on a temperature of an engine cylinder valve. The desired AFR may be outside the AFR range available during natural gas combustion alone and thus allows for cooler engine operation.

A method and apparatus to determine values for at least one fuel use characteristic variable which represents a first fuel use process in a first vehicle, are provided. In addition, values are determined for at least one parameter which represents at least one peripheral condition of the fuel use in the first vehicle during the first fuel supply process. A mathematical relationship is determined between one or more supplied values of the at least one fuel use characteristic variable and the corresponding values of the at least one parameter. A profile data record including a data record and/or learning data is supplied on the basis of at least one determined mathematical relationship. At least one further fuel parameter of a fuel which is used by the first vehicle and/or by a second vehicle during a second fuel use process is adapted as a function of the supplied profile data record.