Reductant injection in exhaust manifold

Patent metadata

Field	Value
Publication number	US-2019323403-A1
Application number	US-201916460151-A
Country	US
Kind code	A1
Filing date	Jul 2, 2019
Priority date	Dec 5, 2014
Publication date	Oct 24, 2019
Grant date	—

Abstract

An aftertreatment system comprises a first passageway having a first temperature and a second passageway having a second temperature different than the first temperature. A turbine is disposed downstream from the first passageway and upstream from the second passageway. The turbine is in fluidic communication with the first passageway and the second passageway. The turbine is structured to receive an exhaust gas from the first passageway, generate energy using the exhaust gas flowing through the turbine and communicate the exhaust gas to the second passageway. The aftertreatment system also includes an insertion device structured to insert an exhaust reductant into the first passageway. A selective catalytic reduction system is configured to receive the exhaust gas from the second passageway and treat the exhaust gas. The first temperature can be higher than the second temperature.

First claim

1 - 10 . (canceled)

11 . An aftertreatment system, comprising:
a turbine a selective catalytic reduction system positioned downstream of the turbine; an exhaust gas loop structured to receive an exhaut gas, the exhaust loop comprising:
a first branch fluidly coupled to the turbine, the first branch structured to communicate a first portion of the exhaust gas into the turbine,
a second branch structured to communicate a second portion of the exhaust gas to a part of the exhaust gas loop downstream of the turbine, the second branch bypassing the turbine so that the second portion of the exhaust gas does not flow through the turbine, the first portion of the exhaust gas and the second portion of the exhaust gas combining downstream of the turbine; and an insertion device structured to insert the exhaust reductant into the second branch.

12 . The aftertreatment system of claim 11 , wherein the first portion of the exhaust gas has a first portion first temperature upstream of the turbine and a first portion second temperature downstream of the turbine, the first portion first temperature greater than the first portion second temperature, and wherein the second portion of the exhaust gas has a second portion temperature lower than or equal to the first portion first temperature and higher than the first portion second temperature.

13 . The aftertreatment system of claim 11 , wherein a mesh is positioned upstream of the turbine, the mesh structured to prevent reductant deposits from entering the turbine.

14 . The aftertreatment system of claim 11 , wherein an exhaust valve is positioned upstream of the first branch, the exhaust valve structured to control the flow of the exhaust gas.

15 . The aftertreatment system of claim 11 , wherein an exhaust gas recirculation system is fluidly coupled to the first branch, thereby receiving exhaust gas free of exhaust reductant therefrom.

16 . An apparatus for minimizing exhaust reductant deposits in an aftertreatment system which comprises a first passageway, a second passageway, a turbine positioned downstream of the first passageway and upstream of the second passageway, and a selective catalytic reduction system positioned downstream of the second passageway, the apparatus comprising:
an insertion device structured to insert an exhaust reductant into the aftertreatment system; and a valve positioned downstream of the insertion device, the valve structured to selectively direct the flow of the exhaust reductant into one of the first passageway or the second passageway, the first passageway having a first temperature greater than a second temperature of the second passageway.

17 . The apparatus of claim 16 , wherein the valve is configured to direct the exhaust reductant towards the first passageway if the second temperature of the second passageway is below a minimum threshold.

18 . The apparatus of claim 17 , wherein the valve is configured to the direct the exhaust reductant towards the second passageway if the second temperature of the second passageway is above the minimum threshold.

19 . The apparatus of claim 16 , wherein the valve comprises a three-way valve.

20 . A method for reducing exhaust reductant deposits in an aftertreatment system which comprises a first passageway, a second passageway, a turbine positioned downstream of the first passageway and upstream of the second passageway, and a selective catalytic reduction system positioned downstream of the second passageway, the method comprising;
flowing an exhaust gas through the aftertreatment system; determining whether a second temperature of the second passageway is lower than a first temperature of the first passageway; in response determining that the second temperature is lower than a minimum threshold, inserting the exhaust reductant into the first passageway.

21 . The method of claim 20 , further comprising:
in response determining that the second temperature is higher than the minimum threshold, inserting the exhaust reductant into the second passageway.

22 . The method of claim 20 , wherein the minimum threshold corresponds to a temperature above which the exhaust reductant completely vaporizes.

23 . The method of claim 20 , wherein an engine is fluidly coupled to the aftertreatment system, the engine producing the exhaust gas, and wherein the method further comprises:
operating the engine employing variable valve timing so as to produce the exhaust gas at the first temperature, the first temperature being sufficient for completely vaporizing the exhaust reductant.

24 . The method of claim 20 , wherein an engine is fluidly coupled to the aftertreatment system, the engine producing the exhaust gas, and wherein the method further comprises:
flowing the exhaust reductant through at least a portion of the engine, the exhaust reductant absorbing heat from the engine so that the exhaust reductant is heated before communicating into the first passageway.

25 . The method of claim 20 , wherein the aftertreatment system is fluidly coupled to an exhaust gas recirculation system, and wherein the method further comprises:
flowing the exhaust reductant through at least a portion of the exhaust gas recirculation system, the exhaust reductant absorbing heat from the exhaust gas flowing through the exhaust gas recirculation system before communicating into the first passageway.

Assignees

• Cummins Inc

Inventors

• Heichelbech John K
• Buechler John G
• Ancimer Richard J
• Yonushonis Thomas M

Classifications

• F01N3/2892 Primary

  Exhaust flow directors or the like, e.g. upstream of catalytic device · CPC title

• F01N3/208

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title

• F01N2610/02

  the substance being ammonia or urea · CPC title

• F01N2340/06

  Arrangement of the exhaust apparatus relative to the turbine of a turbocharger · CPC title

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title