Aftertreatment system and method for pre-decomposed reductant solution

摘要

There is disclosed a method and system for pressurizing a reductant solution from a reductant storage device and superheating the pressurized reductant solution. The superheated pressurized reductant solution at least partially decomposes in the heat exchanger and/or a decomposition chamber before it is released into an exhaust system. The at least partially decomposed reductant solution is delivered to the exhaust system upstream of the SCR catalyst.

主权项

1. A system comprising:
an internal combustion engine; an exhaust conduit fluidly coupled to the internal combustion engine; a selective catalytic reduction (SCR) catalyst fluidly coupled to the exhaust conduit; a storage device for storing a reductant solution; a reductant solution delivery system defining a flowpath for delivering superheated reductant to the exhaust conduit at a location upstream of the SCR catalyst, wherein the reductant solution delivery system includes:
a decomposition chamber connected to the exhaust conduit upstream of the SCR catalyst;an orifice along the flowpath opening into the decomposition chamber;a heating device in the flowpath upstream of the orifice; anda metering device in the flowpath upstream of the heating device, wherein the metering device regulates flow of pressurized reductant solution from the storage device to the heating device, wherein the heating device is operable to superheat the pressurized reductant solution for passage through the orifice, wherein the superheated pressurized reductant solution expands through the orifice and flash vaporizes to at least partially decompose in the decomposition chamber before entering the exhaust conduit.