A reserve fuel system can be used to supplement fuel provided to an engine of wellsite equipment. For example, a fuel supply line can transport gaseous fuel at a wellsite to an engine of an equipment coupled to the fuel supply line. A reserve fuel tank can store gaseous fuel diverted from the fuel supply line. The reserve fuel tank can include a first valve coupling a first end of the reserve fuel tank to the fuel supply line to divert the gaseous fuel and a second valve coupling a second end of the reserve fuel tank to the engine. The second valve can be in a closed position to prevent the stored gaseous fuel from transferring to the engine or an open position to transfer the stored gaseous fuel to the engine. A control system can adjust the second valve based on a pressure of the fuel supply line.

Examples are provided for switching an engine fuel supply. One example system includes a direct-injection engine including a cylinder, an LPG tank for storing a LPG fuel, a CNG tank for storing a CNG fuel, a gas switching valve, a high-pressure pump connected between the LPG tank and the gas switching valve, a pressure-limiting valve connected between the CNG tank and the gas switching valve, a fuel distributor configured to be supplied with one or more of the LPG fuel and the CNG fuel via the gas switching valve, an LPG injection valve coupled to the cylinder, a CNG injection valve coupled to the cylinder, the LPG injection valve and the CNG injection valve configured to be supplied with fuel via the fuel distributor; and a controller configured to control the gas switching valve depending on an aggregate state of the fuel disposed in the fuel distributor.

The present invention relates to a method for supplying fuel for a motor of a vehicle by a fuel supply system comprising: a first tank for containing a first fuel; supply means for supplying fuel to the motor; a supply line, for allowing said first fuel to pass from said first tank to said supply means; a return line, for allowing fuel to pass from said supply means to said first tank; a recirculating line, connected with said supply line and said return line, for allowing fuel to pass from said return line to said supply line; and valve means, configured to selectively direct fuel from said return line to said supply line by said recirculating line, or to said first tank; wherein said method comprises the steps of controlling the speed vehicle; controlling the vehicle motor load; defining a first threshold value of the vehicle speed; defining a second threshold value for the vehicle motor load; letting said first fuel passing from said first tank to said supply means through said supply line, and from said supply means to said first tank through said return line, preventing passage of fuel along said recirculating line, when the vehicle speed is lower than said first threshold value and/or motor load is lower than said second threshold value; or making said first fuel passing from said first tank to said supply means through said supply line and then through a closed circuit comprising a part of said return line, said recirculating line and a portion of said supply line, permitting passage of said first fuel through said recirculating line, so that said first fuel arrives again within said supply means, when the vehicle speed is higher than said first threshold value and motor load is higher than said second threshold value, so as to prevent an excessive increase within said first tank caused by inlet within the first tank of the first fuel warm arriving from said supply means.

A fuel system for a bi-fuel vehicle, which is provided with an engine and an LPG tank connected to each other through a fuel supply line and a fuel return line through which liquefied petroleum gas (LPG) fuel passes, includes: a 3-way valve which is installed in the fuel return line, and selectively opened and closed to move returning LPG fuel to a canister connected with a fuel tank; and a return tube, which branches off from the fuel return line, installed so that the returning LPG fuel passes through the canister in accordance with an operation of the 3-way valve, allowing the LPG fuel of which the temperature is decreased by heat exchange while the LPG fuel passes through the canister to move to the fuel return line.

A pressure regulator including an inlet port for receiving a fuel supply, a first outlet port in fluid communication with a main combustion chamber and a second outlet port in fluid communication with a pre-combustion chamber in an engine is provided. A first valve is located within the first outlet port and a first actuator is configured to operate the first valve to regulate a fuel supply through the first outlet port to the main combustion chamber. A second valve is located within the second outlet port and a second actuator is configured to operate the second valve to control a fuel supply through the second outlet port to the pre-combustion chamber.

A hydrogen regulation module for a hydrogen internal combustion engine includes a common body that defines therein a gas flow path for a hydrogen stream, the gas flow path extending from an inlet port to an outlet port the common body integrating: a shut off valve to selectively open or close the flow of hydrogen through the gas flow path; a pressure regulating valve configured to regulate the pressure of the hydrogen stream towards the outlet; a purge valve configured to allow purging the gas flow path downstream of the shut off valve; a first pressure relief valve in fluid communication with the gas flow path downstream of the shut off valve and of the pressure regulating valve; and a filter unit to retain particles beyond a predetermined particle size, arranged upstream of the shut off valve and pressure regulating valve. A temperature sensor and a pressure sensor on the hydrogen stream are upstream of the shut off valve and of the pressure regulating valve.