DUAL FUEL SYSTEM FOR AN INTERNAL COMBUSTION ENGINE

摘要

A dual fuel system provides first and second fuels to internal an engine. Both fuels are stored in a storage tank, separated by a flexible membrane. A fuel rail receives either or both of the fuel types and distributes the fuels to fuel injectors. Upon shutdown of the engine, the second fuel is evacuated from the fuel rail into an auxiliary tank. The first fuel is subsequently supplied to the fuel rail from the storage tank. Upon a restarting of the engine after a predetermined time subsequent to the shutdown of the engine, the first fuel from the fuel rail is used for combustion. The second fuel from the auxiliary tank is then slowly bled into the engine or intake manifold. As the first fuel from the storage tank continues to supply the fuel rail, and the second fuel begins to supplement the first fuel in the fuel rail.

主权项

1. A dual fuel system for a vehicle capable of being propelled by two different fuels, the system comprising:
at least one supply tank having a first compartment and a second compartment for supplying a first fuel and a second fuel, respectively; a fuel rail capable of delivering the first fuel and the second fuel to fuel injectors; at least one fuel line connecting the first and second compartments of the supply tank to the fuel rail; at least one valve disposed along the at least one fuel line for selectively distributing the first and second fuels from the supply tank to the fuel rail; an evacuation tank; an evacuation line having an inlet fluidly connected to the fuel rail, and an outlet fluidly connected to the evacuation tank; an evacuation valve disposed along the evacuation line for selectively communicating fuel from the fuel rail to the evacuation tank; and at least one controller programmed to (i) open the evacuation valve to evacuate the second fuel from the fuel rail into the evacuation tank in response to an engine-OFF signal, (ii) subsequently open the at least one valve to deliver the first fuel into the fuel rail, and (iii) controllably inject the first fuel via the fuel injectors at a first rate in response to an engine-ON signal.