A dual-fuel supply system (100) for direct injection for engines of heavy vehicles, comprising: a supply line of a combustible liquid (160); a supply line of a combustible gas (170); a plurality of injectors (150) in fluid communication with the supply line of the combustible liquid (160) and with the supply line of the combustible gas (170); a pressure regulator device (1) for regulating the combustible gas; an electronic control unit (ECU) configured to control the supply of combustible liquid and of the combustible gas to the injectors (150), the electronic control unit (ECU) being configured to control the pressure regulator device (1) to track a reference pressure (p.sub.target) according to a feedback logic.

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 density 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.

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).

A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a voltage sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel configured to supplement a primary fuel used by an engine. The electronic valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The voltage sensor is configured to acquire voltage data from a power supply indicative of a voltage of the power supply. The power supply is configured to receive power from an alternator driven by the engine. The controller is configured to control the electronic valve such that the electronic valve is (i) closed in response to the voltage being less than a voltage threshold and (ii) open or openable in response to the voltage being greater than the voltage threshold.

A supplemental fuel system for a machine having a compression-ignition engine includes an air intake tube. The air intake tube has a first end configured to interface with an air cleaner of an air supply system that provides air to the compression-ignition engine, a second end configured to interface with a compressor of a turbocharger of the air supply system, and a sidewall extending between the first end and the second end. The sidewall includes a fuel interface configured to facilitate providing a supplemental fuel into the air intake tube to mix with the air upstream of the compressor of the turbocharger.

An apparatus of charging Liquefied Petroleum Gas (LPG) fuel of a bi-fuel vehicle includes: a gasoline mixing chamber mounted on an LPG bombe side, a gasoline fuel supply line connecting the gasoline mixing chamber with a fuel tank and allowing gasoline fuel to move to the gasoline mixing chamber as a first valve is open, an LPG fuel supply line connecting an LPG bombe with the gasoline mixing chamber and allowing LPG fuel to move to the gasoline mixing chamber as a second valve is open, and a control unit configured to open the first valve and control the LPG fuel to be recirculated to the LPG bombe together with the gasoline fuel by a pressure of the LPG fuel moving to the gasoline mixing chamber, as an internal pressure of the LPG bombe reaches a predetermined reference pressure.

Methods and systems are provided for a multi-fuel engine. In one example, a method includes increasing a temperature reducing mass of a combustion mixture during a transition to multi-fuel combustion from single-fuel combustion.

A supplemental fuel system for a machine having a compression-ignition engine includes an air intake tube. The air intake tube has a first end configured to interface with an air cleaner of an air supply system that provides air to the compression-ignition engine, a second end configured to interface with a compressor of a turbocharger of the air supply system, and a sidewall extending between the first end and the second end. The sidewall includes a fuel interface configured to facilitate providing a supplemental fuel into the air intake tube to mix with the air upstream of the compressor of the turbocharger.

A supplemental fuel system includes a fuel mixer having a nozzle and a stem. The nozzle is configured to be positioned within a conduit of an air supply system for an engine. The nozzle has a body defining a first inlet, an outlet, a passage extending from the first inlet to the outlet, and a second inlet positioned between the first inlet and the outlet. The body has a first cross-sectional dimension that is configured to be less than a second cross-sectional dimension of the conduit such that (i) a first portion of air flowing through the conduit flows through the passage and (ii) a second portion of the air flowing through the conduit flows around the nozzle. The stem has a first end that interfaces with the second inlet. The stem is configured to extend through a wall of the conduit.

A generator and off-board fuel delivery system is disclosed. The generator is configured to operate on one or more fuels, including on a gaseous fuel supplied from a pressurized fuel source through a gaseous fuel line. A fuel regulator system is located off board the generator and is configured to regulate the gaseous fuel supplied from the pressurized fuel source in a first stage, with the gaseous fuel regulated down to a reduced pressure in the first stage. A second stage of the fuel regulator system regulates the reduced pressure gaseous fuel, with the reduced pressure gaseous fuel from the first stage regulated down to a desired pressure in the second stage for delivery through the gaseous fuel line to operate the generator.