A method for controlling fuel pressure in an internal combustion engine consuming a gaseous fuel and a liquid fuel comprises steps of determining a gaseous fuel pressure target value as a function of an engine operating condition, pressurizing the liquid fuel to a liquid fuel pressure based on the gaseous fuel pressure target value, and regulating gaseous fuel pressure from the liquid fuel pressure. The gaseous fuel pressure equals the gaseous fuel pressure target value to within a predetermined range of tolerance. A corresponding apparatus controls fuel pressure in a gaseous fuelled internal combustion engine.

A method for controlling fuel pressure in an internal combustion engine consuming a gaseous fuel and a liquid fuel comprises steps of determining a gaseous fuel pressure target value as a function of an engine operating condition, pressurizing the liquid fuel to a liquid fuel pressure based on the gaseous fuel pressure target value, and regulating gaseous fuel pressure from the liquid fuel pressure. The gaseous fuel pressure equals the gaseous fuel pressure target value to within a predetermined range of tolerance. A corresponding apparatus controls fuel pressure in a gaseous fuelled internal combustion engine.

A method for controlling fuel pressure in an internal combustion engine consuming a gaseous fuel and a liquid fuel comprises steps of determining a gaseous fuel pressure target value as a function of an engine operating condition, pressurizing the liquid fuel to a liquid fuel pressure based on the gaseous fuel pressure target value, and regulating gaseous fuel pressure from the liquid fuel pressure. The gaseous fuel pressure equals the gaseous fuel pressure target value to within a predetermined range of tolerance. A corresponding system controls fuel pressure in a gaseous fuelled internal combustion engine.

A bi-fuel and dual-fuel engine variable pressure fuel system is presented facilitating individual or simultaneous use of liquid and gaseous fuels including natural gas, hydrogen and gasoline, through employment of a variable output pressure gaseous fuel regulator incorporating an attached hydraulic amplifying structure communicating with a relatively low pressure fluid servo circuit that may in turn communicate with a variable pressure automotive liquid fuel system to facilitate relatively high pressure gaseous fuel injection.

For powering a vehicle, a high energy density fuel is preferred. However, for example when the high energy fuel is highly concentrated hydrogen peroxide, this fuel may be dangerous to handle; especially when the person handling the fuel is a normal consumer filling a fuel reservoir of his vehicle at a gas station. The present invention therefore provides a vehicle arranged to receive a diluted-and thus safer-fuel, and to densify this fuel to a concentrated fuel in low quantities on board for direct use. To this end a fuel densifier is provided in the vehicle arranged for receiving liquid diluted fuel and arranged to provide a concentrated fuel based on the diluted fuel, the concentrated fuel having a higher energy density than the diluted fuel. A power conversion module of the vehicle is arranged to convert the concentrated fuel to kinetic energy for powering the vehicle.

An improved fuel system for a dual-fuel internal combustion engine. During normal operation, the primary fuel passes through a pressure regulator before arriving at a primary fuel rail. Further, pressurized secondary fuel is delivered to both a secondary fuel rail and to the pressure regulator for purposes of regulating the output pressure of the primary fuel that is delivered to the primary fuel rail. When the pressure at the primary fuel supply or between the primary fuel supply and the pressure regulator drops below a minimum operating pressure, the pressure regulator is isolated from the secondary fuel and the secondary fuel continues to be pressurized until it reaches a suitable pressure for operating in a limp mode. Then, the secondary fuel, which is pressurized to greater than a normal operating pressure, may be injected at the higher pressure for improved performance of the engine in the limp mode.

A mechanical fuel lockout switch for a dual fuel engine includes a mechanical fuel valve actuatable between a first position and a second position to selectively control fuel flow to the dual fuel engine from a first fuel source through a first fuel line and a second fuel source through a second fuel line. The mechanical fuel lockout switch may also include a fuel lockout apparatus coupled to the mechanical fuel valve. The mechanical fuel valve may be configured to allow communication between the first fuel source and the dual fuel engine and prevent communication between the second fuel source and the dual fuel engine while in the first position, and prevent communication between the first fuel source and the dual fuel engine while in the second position.

A pressure regulation system for a gaseous fluid includes a gaseous fluid supply and a hydraulic fluid supply of a hydraulic fluid. A rail injector is in fluid communication with the gaseous fluid supply and the hydraulic fluid supply and is hydraulically actuated with the hydraulic fluid. A gaseous-fluid rail is in fluid communication with the rail injector and in selective fluid communication with the gaseous fluid supply. A pressure sensor in fluid communication with the gaseous-fluid rail is responsive to gaseous-fluid rail pressure to emit signals representative thereof. A controller communicatively configured with the pressure sensor and the rail injector is programmed to receive the signals representative of the gaseous-fluid rail pressure to determine a measured gaseous-fluid rail pressure; and to actuate the rail injector to inject the gaseous fluid from the gaseous fluid supply into the gaseous-fluid rail as a function of the measured gaseous-fluid rail pressure.

A fuel enhancement method and system for supplying the engine with a pressurized fuel mixture comprising a mixture of the liquid fuel and the gaseous component including provisions to maintain the ratio of gas to liquid in the mixture at a predetermined value and maintain the pressure of the fuel mixture applied to the engine at a predetermined value. A system using variable speed drive pumps is disclosed.

A computer-implemented method for controlling direct injection of hydrogen fuel into an engine cylinder of a vehicle from a hydrogen tank via an injector system. The method includes determining a present hydrogen pressure in the hydrogen tank; determining a present requested engine torque and speed; determining a target injection pressure for injecting hydrogen into the engine combustion chamber using a model the target injection pressure is the injection pressure that, according to the model, minimizes the mechanical work of the compressor, that provides an in-cylinder pressure sufficient for the engine to provide the requested engine torque and speed, that provides NOx emission below a predetermined maximum NOx emission level, and that reduces engine fuel consumption, and adjusting the injector pressure according to the determined target injection pressure.