Variable pressure gaseous fuel regulator

摘要

Methods and systems are provided for varying fuel injection pressure in a gaseous-fueled vehicle. A mechanical pressure regulator may be modified to regulate the pressure of gaseous fuel to varying pressures based on electronic pressure feedback and engine operating conditions. In one example, a regulating pressure in a low pressure chamber of a pressure regulator may be varied by controllably flowing gaseous fuel into or out of a reference chamber of the pressure regulator, and the gaseous fuel exhausted from the reference chamber may be directed to the engine for combustion.

主权项

1. A method for regulating gaseous fuel pressure in an engine, comprising:
increasing a regulating pressure in a low pressure chamber of a pressure regulator by opening a first valve arranged in a conduit coupling the low pressure chamber with a reference chamber of the pressure regulator and flowing fuel from the low pressure chamber to the reference chamber while closing a second valve arranged in a conduit coupling the reference chamber with an engine intake manifold, and then closing the first valve after a first duration such that both the first and second valves are closed and the reference chamber is sealed; decreasing the regulating pressure by closing the first valve while opening the second valve, and then closing the second valve after a second duration such that both the first and second valves are closed and the reference chamber is sealed.