Various methods and systems are provided for a method for a multi-pressure fueling system. In one example, the multi-pressure fueling system includes providing a first fuel delivery pressure enabling high pressure direct injection of a fuel at a first injector and a second fuel delivery pressure insufficient for high pressure direct injection, at a second injector, based on engine operation.

A supplemental fuel system includes a fuel mixer. The fuel mixer includes a nozzle and a stem. The nozzle is configured to be positioned within a conduit of an air supply system for a compression-ignition engine. The nozzle has a body defining a first inlet positioned at a first nozzle end thereof, an outlet positioned at a second nozzle end thereof, a second inlet positioned between the first nozzle end and the second nozzle end, and a nozzle passage extending from the first nozzle end to the second nozzle end that is configured to receive air flowing through the conduit. The stem has a first stem end interfacing with the second inlet. The stem is configured to extend through a wall of the conduit such that a second stem end is positioned outside of the conduit.

The invented system adds some petrol fuel to the vehicle engine which runs with natural gas (CNG or LPG). It causes a simultaneous combustion of petrol and natural gas (CNG or LPG). This action decreases depreciation of engine, increases power of the engine and reduces fuel consumption in natural gas vehicles. The above-mentioned system consists of an innovative petrol holder storage, an electronically circuit, a relay, a lever micro switch and a petrol fuel injector. Whenever the accelerator pedal is pressed more than a certain amount, the system will be activated and command to inject petrol collected in the storage into the air manifold.

A system for exchanging of different fuels that can be used for operation of an engine. The system includes a fuel exchange unit, a control and an exchange return conduit. The fuel exchange unit is configured to deliver a first fuel at pressure into the injections system given a switched-off engine, in order to replace a second fuel, which is located in the injection system, with the first fuel. A fuel delivery system includes a media converter which includes a deflectable element. The media converter is driven by a drive unit via the fluid by way of the fluid being able to be led at a varying pressure to the media transformer via a first feed conduit, and is configured to deliver the fuel via a pumping effect.

A method may comprise: positioning a pressure control valve (PCV) at an outlet of a fuel rail; positioning a volume control valve (VCV) at an inlet of a high pressure pump; and in response to an exhaust particulate matter (PM) level deviating from a target PM level, adjusting a fuel ratio of a first fuel and a second fuel delivered to an engine, and opening one of the PCV and the VCV. In this way, the fuel oxygen content may be adjusted to maintain a PM at or below a target level without a DPF over a broad range of engine designs and operating conditions, while maintaining fuel economy.

A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a heat exchanger fluidly coupled between a fuel input of the fuel stream and the fuel separator, the heat exchanger configured to transfer heat from the vapor stream to the fuel stream, and output a heated fuel stream to the fuel separator and a second liquid stream defined by the first auto-ignition characteristic value.

In a dual-fuel fuel injector comprising a first injector unit for a first injector operating mode using a first main fuel and a second injector unit for a second injector operating mode using a second main fuel and an injector-reservoir, the reservoir is connected at one end to a first main fuel supply and at the opposite end to a second main fuel supply with a separating element disposed in the injector reservoir so as to be movable between the opposite ends so that, in each operating mode, the full volume of the reservoir can be used for accommodating the respective main fuel.

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.

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 includes a supplemental fuel tank, a first pressure regulator, a second pressure regulator, and a nozzle. The supplemental fuel tank is configured to store a supplemental fuel at a first pressure. The first pressure regulator is configured to reduce the first pressure of the supplemental fuel received from the supplemental fuel tank to a second pressure. The second pressure regulator is configured to reduce the second pressure of the supplemental fuel received from the first pressure regulator to a third pressure. The nozzle is configured to be positioned (i) downstream of the second pressure regulator and (ii) within a conduit of an air supply system for the compression-ignition engine. The nozzle is configured to receive a flow of the supplemental fuel and provide the supplemental fuel to air flowing though the conduit.