Dual Fuel Injector with Hydraulic Locking Seal and Liquid Leakage Cleaning Strategy

摘要

A dual fuel system includes a dual fuel injector that includes a gaseous fuel inlet, a gas nozzle outlet set, a liquid fuel inlet, and a liquid nozzle outlet set. Disposed in the dual fuel injector is a gas nozzle chamber that is fluidly connected to the gaseous fuel inlet and a liquid nozzle chamber that is fluidly connected to the liquid fuel inlet. The dual fuel injector also includes a hydraulically locking seal with an annular volume for liquid fuel surrounding a guide segment of a needle valve member for gaseous fuel to prevent gaseous fuel from migrating into the liquid fuel. A gaseous fuel common rail is fluidly connected to the gaseous fuel inlet and a liquid fuel common rail is fluidly connected to the liquid fuel inlet. A check valve is fluidly positioned between the gaseous fuel common rail and the gas nozzle chamber of the dual fuel injector to prevent liquid fuel that has leaked into the gas nozzle chamber through the hydraulically locking seal from entering the gaseous fuel common rail.