Patent ID: 8276366

Claim:
A closely-coupled exhaust aftertreatment system for an internal combustion engine having twin turbochargers, comprising: a first exhaust conduit comprising a first valve operable between a first position and a second position, the first position promoting an exhaust flow within the first exhaust conduit to an inlet of an oxidation catalyst (OC), and the second position promoting the exhaust gas flow within a second exhaust conduit; a third exhaust conduit fluidly coupled to an outlet of the OC, the third exhaust conduit comprising a second valve operable between a first position and a second position; the first position promoting an exhaust flow within the third exhaust conduit to an inlet of a particulate filter (PF), and the second position promoting the exhaust gas flow through a fourth exhaust conduit to an inlet in the second exhaust conduit; a first turbocharger that is fluidly coupled to the second exhaust conduit downstream of the inlet; a selective catalyst reduction (SCR) catalyst that is located downstream of and fluidly coupled to the first turbocharger to receive the exhaust gas flow therefrom and located upstream of and fluidly coupled to the PF to provide the exhaust gas flow thereto; and a second turbocharger that is fluidly coupled to the third exhaust conduit downstream of the second valve.