Patent attributes
An exhaust after-treatment system is coupled to an exhaust pipe of a diesel internal combustion engine (ICE) for treating an exhaust gas. The exhaust after-treatment system includes a diesel oxidation catalyst (DOC) and a SCR coated diesel particulate filter (SDPF) serially disposed in a downstream path of the exhaust gas. An electrically heated catalyst (EHC) is coupled to the DOC and is configured to electrically heat the DOC for reducing the requisite time to reach a DOC light-off temperature. A controller is operably coupled with the DOC and the EHC and is configured to operate the EHC in response to a mid bed temperature of the DOC. More specifically, the controller is configured to supply power to the EHC when the DOC mid bed temperature is below a predetermined value and discontinue the power supply to the EHC when the DOC mid bed temperature is greater than the predetermined value.
