ENHANCED FUEL INJECTION BASED ON CHOKE FLOW RATE

摘要

A method is described for adjusting the amount of gaseous fuel injected based on the sonic choked flow rate through a restriction. Because the sonic choke flow rate continues to decrease as tank pressure decreases, the method includes computing the sonic choke flow rate through the restriction based on system variables and enforcing the rate of CNG injection to be less than the sonic choke flow rate through the restriction. Thereby, the mass flow rate to the fuel injector can be substantially maximized to substantially minimize the time for fuel tank emptying, particularly during the last amount of tank emptying when the contents of the gaseous storage tank is low.

主权项

1. A method for operating an engine while emptying a gaseous fuel tank, comprising:
coupling a gaseous fuel from the tank to a fuel injector through a restriction; and controlling mass flow rate from said fuel injector to the engine to be on average less than choked sonic mass flow rate of said gaseous fuel through said restriction.