A control device of an internal combustion engine comprises a heater control part configured to set a target temperature of the electrochemical cell and control the heater so that a temperature of the electrochemical cell becomes the target temperature. The heater control part sets the target temperature to a first temperature when water injection by the water injection device is not being demanded after a predetermined time elapses from startup of the internal combustion engine, and sets the target temperature to a second temperature when an operating state of the internal combustion engine is in a water outflow state where water injected by the water injection device reaches the exhaust passage without going through combustion of air-fuel mixture in the combustion chamber. The second temperature is higher than the first temperature.

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 reducing coking deposits in a fuel injection system. In one example, a method may comprise humidifying intake air of an intake system of an engine in response to a determination that fuel injector coking is occurring, or after a duration has passed since a most recent humidification event. A humidifying fluid, such as water, may be injected into the intake system to humidify the intake air, and the resulting humidified intake air may reduce and/or remove coking deposits on one or more direct fuel injectors of the fuel injection system.

Methods and systems are provided for reducing coking deposits in a fuel injection system. In one example, a method may comprise humidifying intake air of an intake system of an engine in response to a determination that fuel injector coking is occurring, or after a duration has passed since a most recent humidification event. A humidifying fluid, such as water, may be injected into the intake system to humidify the intake air, and the resulting humidified intake air may reduce and/or remove coking deposits on one or more direct fuel injectors of the fuel injection system.

The condensed water treatment device increases the EGR quantity (S16, S17) so as to be larger than the EGR quantity (Qe) calculated based on the operating state, when within a specific time period (S13) from a moment when execution of filter regeneration control is started to a moment after predetermined time has elapsed following the end of the execution, and also in a case where (S15) the storage water quantity (Qw) of a condensed water tank storing condensed water generated in an EGR cooler is smaller than a normative water quantity (Qwt).

The condensed water treatment device increases the EGR quantity (S16, S17) so as to be larger than the EGR quantity (Qe) calculated based on the operating state, when within a specific time period (S13) from a moment when execution of filter regeneration control is started to a moment after predetermined time has elapsed following the end of the execution, and also in a case where (S15) the storage water quantity (Qw) of a condensed water tank storing condensed water generated in an EGR cooler is smaller than a normative water quantity (Qwt).

An internally cooled internal combustion piston engine and method of operating a piston engine is provided, with the combination of liquid water injection, higher compression ratios than conventional engines, and leaner air fuel mixtures than conventional engines. The effective compression ratio of the engines herein is greater than 13:1. The engines may employ gasoline or natural gas and use spark ignition, or the engines may employ a diesel-type fuel and use compression ignition. The liquid water injection provides internal cooling, reducing or eliminating the heat rejection to the radiator, reduces engine knock, and reduces NOx emissions. The method of engine operation using internal cooling with liquid water injection, high compression ratio and lean air fuel mixture allow for more complete and efficient combustion and therefore better thermal efficiency as compared to conventional engines.

An internally cooled internal combustion piston engine and method of operating a piston engine is provided, with the combination of liquid water injection, higher compression ratios than conventional engines, and leaner air fuel mixtures than conventional engines. The effective compression ratio of the engines herein is greater than 13:1. The engines may employ gasoline or natural gas and use spark ignition, or the engines may employ a diesel-type fuel and use compression ignition. The liquid water injection provides internal cooling, reducing or eliminating the heat rejection to the radiator, reduces engine knock, and reduces NOx emissions. The method of engine operation using internal cooling with liquid water injection, high compression ratio and lean air fuel mixture allow for more complete and efficient combustion and therefore better thermal efficiency as compared to conventional engines.

A system for injecting an aqueous solution into an injection engine, includes: a tank for an aqueous solution, a circuit for supplying aqueous solution to the tank and a filter for filtering the aqueous solution, and a circuit for recirculating the aqueous solution. The injection system also includes recirculation of the aqueous solution, and is provided with an electrovalve including a first inlet connected to a filler neck of the tank, a second inlet connected to the recirculation circuit, and an outlet connected to the supply circuit. The filtration filter is arranged in the supply circuit and/or in the recirculation circuit.

A system for injecting an aqueous solution into an injection engine, includes: a tank for an aqueous solution, a circuit for supplying aqueous solution to the tank and a filter for filtering the aqueous solution, and a circuit for recirculating the aqueous solution. The injection system also includes recirculation of the aqueous solution, and is provided with an electrovalve including a first inlet connected to a filler neck of the tank, a second inlet connected to the recirculation circuit, and an outlet connected to the supply circuit. The filtration filter is arranged in the supply circuit and/or in the recirculation circuit.