Abstract: The invention relates to a bi-fuel system (100) and a method for operating such a system, in which the following steps are performed by a control system (104) being part of the bi-fuel system (100): determining whether a relative amount of first fuel in the second fuel tank (2) is less than a predetermined minimum relative amount of first fuel in the second fuel tank (MIX %_min), and if said relative amount is less than MIX %_min, supplying first fuel via the fuel return line (18) to the second fuel tank (2), by temporarily opening the return line shut-off valve (12).

Abstract: A method of switching between liquefied gas fuel and liquid fuel consuming modes of a direct injection combustion engine including pumping liquefied gas fuel to a high pressure, pump for pumping the liquefied gas fuel to a high pressure rail of the engine during the liquefied gas fuel consuming mode, switching to the liquid fuel consuming mode, pumping the liquid fuel to the high pressure pump, flushing liquefied gas fuel via a return line between the high pressure pump and a fuel tank, controlling pump operation, controlling flow through the return line, and controlling the pressure of the fuels.

Abstract: A method of switching between liquefied gas fuel and liquid fuel consuming modes of a direct injection combustion engine including pumping liquefied gas fuel to a high pressure,pump for pumping the liquefied gas fuel to a high pressure rail of the engine during the liquefied gas fuel consuming mode, switching to the liquid fuel consuming mode, pumping the liquid fuel to the high pressure pump, flushing liquefied gas fuel via a return line between the high pressure pump and a fuel tank, controlling pump operation, controlling flow through the return line, and controlling the pressure of the fuels.

Abstract: A direct injection bi-fuel system includes a first fuel subsystem, a second fuel subsystem, and a junction configured to receive first fuel from the first fuel subsystem when the system is operating in a first fuel consuming mode, and to receive second fuel from the second fuel subsystem when the system is operating in a second fuel consuming mode. A pump is configured to receive the fuel passing through the junction and pump the fuel to a high pressure rail of a combustion engine, and a purging unit is configured to purge the second fuel from the rail when the system is switched from the second fuel consuming mode to the first fuel consuming mode. The purging unit includes a piston and is configured to receive the second fuel on one side of the piston and the first fuel on the other side of the piston.

Abstract: A device suitable for supplying a gaseous fuel to an internal combustion engine having combustion chambers includes an evaporator with a metering device, the metering device on an inlet side being in communication with an evaporating chamber disposed within the evaporator, and on an outlet side being provided with a main pipe, the main pipe downstream from the metering device branching into a number of pipes connected to individual combustion chambers. Each pipe is provided with a fixed predetermined local constriction, across which at least 85% of the pressure drop from the division of the main pipe into the individual pipes to the combustion chambers takes place, whereby the differences in the flow resistances of the local constrictions of the individual pipes are 5% at most.