Method of estimating hydrocarbon storage in a catalytic device

摘要

A method of estimating hydrocarbon storage in a catalytic device of an exhaust gas treatment system includes calculating an amount of hydrocarbons absorbed in the catalytic device per unit volume of exhaust gas over a period of time, calculating an amount of hydrocarbons desorbed in the catalytic device per unit volume of exhaust gas over the period of time, and calculating an amount of hydrocarbons oxidized in the catalytic device per unit volume of exhaust gas over the period of time. The amount of hydrocarbons oxidized in the catalytic device and the amount of hydrocarbons desorbed in the catalytic device are subtracted from the amount of hydrocarbons absorbed in the catalytic device to determine the amount of hydrocarbons stored in the catalytic device.

主权项

1. A method of estimating hydrocarbon storage in a catalytic device of an exhaust gas treatment system, the method comprising:
determining hydrocarbon absorption by the catalytic device over a period of time, hydrocarbon desorption by the catalytic device over the period of time, and hydrocarbon oxidation in the catalytic device over the period of time; estimating the hydrocarbon storage of the catalytic device, with a controller, from the equation:Ω⁢ⅆθHCⅆt=Δ⁡[HC]absorp-Δ⁡[HC]desorp-Δ⁡[HC]oxitres1+tresΔ⁢⁢twhereinΩ⁢ⅆθHCⅆtis the rate of change in hydrocarbon storage per unit volume of the catalytic device, Δ[HC]absorp is the amount of hydrocarbons absorbed in the catalytic device per unit volume of exhaust gas, Δ[HC]desorp is the amount of hydrocarbons desorbed in the catalytic device per unit volume of exhaust gas, Δ[HC]oxi is the amount of hydrocarbons oxidized in the catalytic device per unit volume of exhaust gas, tres is the residence time of the exhaust gas within the catalytic device, and At is the change in time (i.e., time duration); and
controlling the exhaust gas treatment system based upon the estimated hydrocarbon storage of the catalytic device to heat the catalytic device to the light-off temperature to regenerate the catalytic device.