Multi-leg exhaust aftertreatment system and method

摘要

An exhaust aftertreatment system for treating exhaust flow from an internal combustion engine, and associated method, allows for independent control of exhaust flow through plural exhaust legs of the exhaust aftertreatment system. The independent control of exhaust flow is carried out by adjusting a valve positioned in each the exhaust legs based on a value of a signal generated by a flow measurement device positioned along at least one of the exhaust legs. The valves can be adjusted to force a target flow in a exhaust leg, relative flow among exhaust legs, exhaust temperature in an exhaust leg, exhaust backpressure and/or imbalance within the exhaust legs.

主权项

1. An exhaust aftertreatment system for treating exhaust flow from an internal combustion engine, comprising:
a first exhaust leg positioned to receive the exhaust flow from the engine, said first exhaust leg including:
a first selective catalytic reducer (SCR);a first reductant dosing system including a doser upstream of the first SCR and configured to inject reductant into an exhaust stream in the first exhaust leg; anda first exhaust flow control valve positioned along said first exhaust leg; a second exhaust leg positioned to receive the exhaust flow from the engine in parallel to the exhaust flow in the first exhaust leg, said second exhaust leg including:
a second SCR positioned along the second exhaust leg;a second reductant dosing system including a doser upstream of the second SCR and configured to inject reductant into an exhaust stream in the second exhaust leg; anda second exhaust flow control valve positioned along the second exhaust leg; a flow measurement device positioned along at least one of the first and second exhaust legs and configured to generate a signal indicative of a characteristic of exhaust mass flow or exhaust volume flow of the exhaust stream in that leg; and an electronic control module configured to:
receive the signal indicative of a characteristic of exhaust mass flow or exhaust volume flow from the flow measurement device;determine exhaust mass flow or exhaust volume flow of the exhaust stream in at least one of the first and second exhaust legs based on the received signal; andindependently control the first and second exhaust valves based on the determined exhaust mass flow or exhaust volume flow.