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 fuel heating apparatus and method are disclosed where a conductive coil is wrapped around an outer surface of at least a portion of a nozzle of a fuel injector. The coil and the nozzle are inductively cooperative with each other such that the coil, in response to a variable current through the coil, induces a heating of the nozzle. The inductively heated nozzle can heat fuel passing into an engine so as to cause the fuel to combust as it exits the heated nozzle. This arrangement allows for sparkles combustion of fuel in an internal combustion engine.

A fuel injector has a seat and at least one seat passage. The seat includes an outer tip surface through which the seat passage extends. Fin structure is provided in the outer tip surface and is constructed and arranged to increase a surface area of the outer tip surface as compared to a surface area of the outer tip surface absent the fin structure. The outer tip surface, including the fin structure, is constructed and arranged to be heated by combustion gases so that the outer tip surface reaches a temperature greater than a temperature that the outer tip surface would reach absent the fin structure, so as to cause evaporation of fuel that contacts the outer tip surface.

A fuel injector has a seat and at least one seat passage. The seat includes an outer tip surface through which the seat passage extends. Fin structure is provided in the outer tip surface and is constructed and arranged to increase a surface area of the outer tip surface as compared to a surface area of the outer tip surface absent the fin structure. The outer tip surface, including the fin structure, is constructed and arranged to be heated by combustion gases so that the outer tip surface reaches a temperature greater than a temperature that the outer tip surface would reach absent the fin structure, so as to cause evaporation of fuel that contacts the outer tip surface.

A fuel injection system in the present invention is provided with a fuel injection valve (10) which incorporates a heater (20) for heating fuel before being injected. The temperature of the heater (20) is estimated on the basis of the resistance value R.sub.Htr of the heater (20). The temperature of the heater (20) estimated at or after the time of occurrence of a point of inflection in the resistance value R.sub.Htr of the heater (20) is corrected in order to reduce to zero the difference between the nucleate boiling start point temperature and the estimated temperature value of the heater (20) at the time of occurrence of the point of inflection.

A fuel injection system in the present invention is provided with a fuel injection valve (10) which incorporates a heater (20) for heating fuel before being injected. The temperature of the heater (20) is estimated on the basis of the resistance value R.sub.Htr of the heater (20). The temperature of the heater (20) estimated at or after the time of occurrence of a point of inflection in the resistance value R.sub.Htr of the heater (20) is corrected in order to reduce to zero the difference between the nucleate boiling start point temperature and the estimated temperature value of the heater (20) at the time of occurrence of the point of inflection.

A fuel heater including an engine that is driven by combustion of air-fuel mixture including air and fuel supplied to a combustion chamber within a cylinder, a battery that stores electricity, and a motor that drives the engine by the electricity supplied from the battery, the fuel heater includes a fuel heating portion heating the fuel with the electricity supplied from the battery, and a controller performing one of a first control by increasing the amount of electricity supplied from the battery to the fuel heating portion and a second control by increasing heating time of the fuel by the fuel heating portion for a time period until the engine starts in a case where a battery charge remaining of the battery is equal to or smaller than a remaining threshold value at a start of the engine.

A fuel heater including an engine that is driven by combustion of air-fuel mixture including air and fuel supplied to a combustion chamber within a cylinder, a battery that stores electricity, and a motor that drives the engine by the electricity supplied from the battery, the fuel heater includes a fuel heating portion heating the fuel with the electricity supplied from the battery, and a controller performing one of a first control by increasing the amount of electricity supplied from the battery to the fuel heating portion and a second control by increasing heating time of the fuel by the fuel heating portion for a time period until the engine starts in a case where a battery charge remaining of the battery is equal to or smaller than a remaining threshold value at a start of the engine.

A circuit configuration for inductively heating a fuel injector, includes an injection valve heater coil having connections forming first and second nodes, a capacitor connected parallel to the heater coil, a first inductor connected between a positive pole of a supply voltage and the first node, a second inductor connected between the positive pole of the supply voltage and the second node, a first controllable switching element connected between the first node and a negative pole of the supply voltage, a second controllable switching element connected between the second node and the negative pole of the supply voltage, and a control unit connected to control inputs of the switching elements for applying a switch-on level to the control inputs when the voltage at the respective node connected to a switching element becomes 0 and for dimensioning a switch-on duration of the switching element according to a preset heating power.

A circuit configuration for inductively heating a fuel injector, includes an injection valve heater coil having connections forming first and second nodes, a capacitor connected parallel to the heater coil, a first inductor connected between a positive pole of a supply voltage and the first node, a second inductor connected between the positive pole of the supply voltage and the second node, a first controllable switching element connected between the first node and a negative pole of the supply voltage, a second controllable switching element connected between the second node and the negative pole of the supply voltage, and a control unit connected to control inputs of the switching elements for applying a switch-on level to the control inputs when the voltage at the respective node connected to a switching element becomes 0 and for dimensioning a switch-on duration of the switching element according to a preset heating power.