A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.

A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.

A method to control the combustion of a compression ignition engine having the steps of: establishing, for each combustion cycle, a fuel quantity to be injected into the cylinder; injecting a first fraction of the fuel quantity; heating a second fraction of the fuel quantity, which is equal to the remaining fraction of the fuel quantity, to an injection temperature higher than 100° C.; injecting the second fraction of the fuel quantity heated to the injection temperature into the cylinder at the end of the compression stroke and at no more than 60° from the top dead centre; and decreasing the injection temperature and the ratio between the second fraction and the first fraction as the internal combustion engine increases and as the rotation speed of the internal combustion engine increases.

A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.

A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.

An engine system includes a combustion chamber including a cylinder formed in an engine and a piston configured to reciprocate inside the cylinder, a spark plug disposed in a ceiling part of the combustion chamber, and a water injection device configured to inject water into the combustion chamber through a plurality of nozzle holes facing the inside of the combustion chamber. The piston has a cavity in an upper surface thereof. The water injection device injects water into the cavity in a compression stroke at a timing when an extension of axes of at least some of the nozzle holes intersects the cavity. The cavity has a bottom part where the water injected by the water injection device collides, and a raising part configured to raise the water spreading along the bottom part toward the water injection device.

An engine system includes a combustion chamber including a cylinder formed in an engine and a piston configured to reciprocate inside the cylinder, a spark plug disposed in a ceiling part of the combustion chamber, and a water injection device configured to inject water into the combustion chamber through a plurality of nozzle holes facing the inside of the combustion chamber. The piston has a cavity in an upper surface thereof. The water injection device injects water into the cavity in a compression stroke at a timing when an extension of axes of at least some of the nozzle holes intersects the cavity. The cavity has a bottom part where the water injected by the water injection device collides, and a raising part configured to raise the water spreading along the bottom part toward the water injection device.

Hydraulically actuated gaseous fuel injectors required a relatively small pressure bias between hydraulic fluid and gaseous fuel to be able to open and to reduce hydraulic fluid contamination of the gaseous fuel. An improved hydraulically actuated gaseous fuel injector includes an injection valve in fluid communication with a gaseous fuel inlet and includes a valve member reciprocatable within a fuel injector body between a closed position and an open position. There is a lift chamber in fluid communication with a hydraulic fluid inlet such that hydraulic fluid pressure in the lift chamber contributes to an opening force applied to the valve member. A control chamber is in fluid communication with the hydraulic fluid inlet such that hydraulic fluid pressure in the control chamber contributes to a closing force applied to the valve member. A control valve is operable to reduce hydraulic fluid pressure in the control chamber such that the opening force is greater than the closing force and the valve member moves to the open position.

Hydraulically actuated gaseous fuel injectors required a relatively small pressure bias between hydraulic fluid and gaseous fuel to be able to open and to reduce hydraulic fluid contamination of the gaseous fuel. An improved hydraulically actuated gaseous fuel injector includes an injection valve in fluid communication with a gaseous fuel inlet and includes a valve member reciprocatable within a fuel injector body between a closed position and an open position. There is a lift chamber in fluid communication with a hydraulic fluid inlet such that hydraulic fluid pressure in the lift chamber contributes to an opening force applied to the valve member. A control chamber is in fluid communication with the hydraulic fluid inlet such that hydraulic fluid pressure in the control chamber contributes to a closing force applied to the valve member. A control valve is operable to reduce hydraulic fluid pressure in the control chamber such that the opening force is greater than the closing force and the valve member moves to the open position.

A method to control the combustion of a compression ignition engine having the steps of: establishing, for each combustion cycle, a fuel quantity to be injected into the cylinder; injecting a first fraction of the fuel quantity; heating a second fraction of the fuel quantity, which is equal to the remaining fraction of the fuel quantity, to an injection temperature higher than 100° C.; injecting the second fraction of the fuel quantity heated to the injection temperature into the cylinder at the end of the compression stroke and at no more than 60° from the top dead centre; and decreasing the injection temperature and the ratio between the second fraction and the first fraction as the internal combustion engine increases and as the rotation speed of the internal combustion engine increases.