Patent ID: 7337607

Claim:
A method for injecting fuel into a transient exhaust stream of an exhaust system, the exhaust system including a catalytic converter positioned upstream from a diesel particulate filter, the exhaust system also including a fuel dispenser positioned upstream from the catalytic converter, the method comprising: selecting a control volume within the exhaust system, the control volume including the fuel dispenser and the catalytic converter; and using a fuel dispensing formula derived from a transient energy balance equation for the control volume to determine a fuel dispensing rate at which fuel is dispensed into the exhaust stream by the fuel dispenser, the fuel dispensing rate being controlled such that combustion of the fuel at the catalytic converter provides a target exhaust gas temperature downstream of the catalytic converter, the target exhaust gas temperature being suitable to cause controlled regeneration of the diesel particulate filter; the transient energy balance equation including a number of factors, at least some of the factors including: a net energy carried by the exhaust stream entering and leaving the control volume; a heat release rate of the fuel to be dispensed into the control volume by the fuel dispenser taking into consideration a fuel vaporization efficiency and a fuel conversion efficiency at the catalytic converter; and a heat transfer rate between the catalytic converter and the exhaust stream.