Variable Pressure Gas Fuel Regulator

Abstract

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.

Description

technical field [0001] The present application relates to variable injection pressure regulation for gaseous fueled vehicles including depressurization of the gaseous fuel rail during conditions in which fuel injectors are deactivated. Background technique [0002] Alternative fuels have been developed to mitigate the rising price of traditional fuels and to reduce exhaust emissions. For example, natural gas has been considered an attractive alternative fuel. For automotive applications, natural gas can be compressed and stored as a gas at high pressure in cylinders. A pressure regulator may then be used to supply compressed natural gas (CNG) to the engine combustion chamber at a lower pressure. The pressure regulator may provide the gaseous fuel to the engine at a fixed, constant pressure, or it may be a variable pressure regulator capable of providing the gaseous fuel to the engine at varying pressures. [0003] Various advantages can be realized by using a variable pre...

AI Technical Summary

Problems solved by technology

However, systems that rely on a single valve to perform pressure regulation may not be robust enough where the valve is subjected to high pressure gaseous fuel flow

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