Dual Fuel Common Rail Transient Pressure Control And Engine Using Same

摘要

A compression ignition engine is fueled from common rail fuel injectors that predominately inject natural gas fuel that is compression ignited with a small pilot injection of liquid diesel fuel. Before and after a rapid fueling increase transient, the liquid and gaseous rail pressures are controlled toward respective pressures based upon engine speed and load. During the transient, the liquid rail pressure is controlled toward an elevated liquid pressure in order to cause a surge in the supply of gaseous fuel to the gaseous fuel common rail to proactively satisfy the increased gaseous fuel injection rate while obviating a substantial pressure deficit in the gaseous fuel common rail.

主权项

1. A method of operating an engine comprising the steps of:
injecting gaseous fuel and liquid fuel directly into an engine cylinder from a gaseous nozzle outlet set and a liquid nozzle outlet set, respectively, of a fuel injector; compression igniting the injected liquid fuel to ignite the gaseous fuel; commanding a transient from a low fuel demand of a first speed and load to a high fuel demand of a second speed and load; obviating a deficit in a gaseous rail pressure during the transient by proactively increasing a mass flow rate of gaseous fuel to a gaseous fuel common rail responsive to the commanding step.