Patent ID: 8171721
Filing Date: 2012-05-08
Classification: F01N,F02D,Y02T

Abstract:
1. A method of providing fuel to an exhaust aftertreatment system, comprising: passing the fuel through a regulating valve comprising an inlet and an outlet, the inlet being connected to a first fuel line, the outlet being connected to an exhaust system fuel supply line that communicates with a nozzle; injecting the fuel from the exhaust system fuel supply line into an exhaust line through the nozzle; obtaining pressure measurements that indicate the exhaust system fuel supply line pressure or a difference between the exhaust system fuel supply line pressure and a pressure of the exhaust line; providing a predetermined relationship that gives the variation of flow rate through the nozzle as a function of the pressure or pressure differential providing a target flow rate; and using the predetermined relationship and the pressure measurements to control the operation of the regulating valve with the pressure measurements providing feedback, the control causing the measured pressure to vary according to the target flow rate and approach whichever pressure the predetermined relationship indicates the flow rate is at the target flow rate.