Patent ID: 8820051

Claim:
A vehicle comprising: an internal combustion engine having an exhaust port; an oxidation catalyst in fluid communication with the engine via the exhaust port, wherein the oxidation catalyst receives an exhaust stream from the engine via the exhaust port; a fuel injection device operable to selectively inject fuel into the oxidation catalyst at an injection rate; a particulate filter in fluid communication with an outlet side of the oxidation catalyst, wherein the particulate filter is regenerable using heat from the oxidation catalyst; and a host machine having a central processing unit (CPU), wherein the host machine is a controller of the vehicle that is configured, via the CPU, to: calculate a mass flow rate of the exhaust stream out of the oxidation catalyst as a function of a density, a velocity, and a cross-sectional area of flow of the exhaust stream; receive a measured outlet temperature of the oxidation catalyst from a temperature sensor positioned at an outlet of the oxidation catalyst; determine an actual total energy input value into the oxidation catalyst using the injection rate and an energy content of the fuel; determine an actual total energy output value from the oxidation catalyst using the calculated mass flow rate, the measured outlet temperature, and a specific heat value of the exhaust stream; calculate an actual conversion efficiency of the oxidation catalyst using the actual energy input value and the actual energy output value; calculate an actual hydrocarbon level in the exhaust stream downstream of the particulate filter as a function of the calculated actual conversion efficiency; and execute a control action with respect to the vehicle when the calculated actual hydrocarbon level exceeds a calibrated threshold.