Aftertreatment system including preheating oxidation and catalyst

Patent metadata

Field	Value
Publication number	US-2023258115-A1
Application number	US-202318134721-A
Country	US
Kind code	A1
Filing date	Apr 14, 2023
Priority date	Sep 13, 2019
Publication date	Aug 17, 2023
Grant date	—

Abstract

A system includes: an engine; and an aftertreatment system for treating exhaust gas produced by the engine, the aftertreatment system including: an exhaust conduit configured to receive the exhaust gas and hydrocarbons from the engine; a preheating oxidation catalyst; a primary oxidation catalyst disposed downstream of the preheating oxidation catalyst; a selective catalytic reduction system disposed in the exhaust conduit downstream of the primary oxidation catalyst. The aftertreatment system includes: a controller configured to: determine a temperature of the exhaust gas at an inlet of the selective catalytic reduction system, and in response to the temperature of the exhaust gas at the inlet of the selective catalytic reduction system being below a threshold temperature, cause the engine to provide the hydrocarbons to the exhaust conduit. The preheating oxidation catalyst is configured to catalyze combustion of the hydrocarbons so as to increase the temperature of the exhaust gas to above the threshold temperature.

First claim

What is claimed is:

1 . A system comprising:
an engine; and an aftertreatment system for treating exhaust gas produced by the engine, the aftertreatment system comprising:
an exhaust conduit configured to receive the exhaust gas and hydrocarbons from the engine;
a preheating oxidation catalyst;
a primary oxidation catalyst disposed downstream of the preheating oxidation catalyst;
a selective catalytic reduction system disposed in the exhaust conduit downstream of the primary oxidation catalyst; wherein:
the aftertreatment system comprises:
a controller configured to:
determine a temperature of the exhaust gas at an inlet of the selective catalytic reduction system, and
in response to the temperature of the exhaust gas at the inlet of the selective catalytic reduction system being below a threshold temperature, cause the engine to provide the hydrocarbons to the exhaust conduit; and

the preheating oxidation catalyst is configured to catalyze combustion of the hydrocarbons so as to increase the temperature of the exhaust gas to above the threshold temperature.

2 . The aftertreatment system as claimed in claim 1 , wherein the controller is configured to cause the engine to provide the hydrocarbons to the exhaust conduit in response to the temperature of the exhaust gas being greater than a light off temperature of the preheating oxidation catalyst.

3 . The aftertreatment system as claimed in claim 2 , further comprising a heater operatively coupled to the preheating oxidation catalyst, wherein the controller is configured to selectively activate the heater in response to the temperature of the exhaust gas being less than the light off temperature of the preheating oxidation catalyst.

4 . The aftertreatment system as claimed in claim 1 , further comprising a hydrocarbon injector disposed between the preheating oxidation catalyst and the primary oxidation catalyst;
wherein the controller is further configured to:
in response to the temperature of the exhaust gas reaching a light off temperature of the primary oxidation catalyst but still being below the threshold temperature, cause the hydrocarbon injector to insert second hydrocarbons into the exhaust gas between the preheating oxidation catalyst and the primary oxidation catalyst.

5 . The aftertreatment system as claimed in claim 1 , wherein the controller is further configured to:
in response to the temperature of the selective catalytic reduction system increasing to be equal to or greater than an upper threshold temperature that is greater than the threshold temperature, cause the engine to stop providing the hydrocarbons to the exhaust conduit.

6 . The aftertreatment system as claimed in claim 1 , wherein the selective catalytic reduction system comprises an upstream catalyst and a downstream catalyst disposed downstream of the upstream catalyst.

7 . The aftertreatment system as claimed in claim 6 , wherein the upstream catalyst comprises a FeZ catalyst.

8 . The aftertreatment system as claimed in claim 6 , wherein the downstream catalyst comprises a CuZ catalyst.

9 . The aftertreatment system as claimed in claim 1 , wherein the preheating oxidation catalyst has a light off temperature that is lower than a light off temperature of the primary oxidation catalyst.

10 . The aftertreatment system as claimed in claim 1 , further comprising a hydrocarbon injector disposed between the preheating oxidation catalyst and the primary oxidation catalyst.

11 . A method for controlling operations of a system that comprises an engine and an aftertreatment system that includes a preheating oxidation catalyst, a primary oxidation catalyst downstream of the preheating oxidation catalyst, and a selective catalytic reduction system disposed downstream of the primary oxidation catalyst, the method comprising:
determining, by a controller, a temperature of the exhaust gas at an inlet of the selective catalytic reduction system; and in response to the temperature of the exhaust gas at the inlet of the selective catalytic reduction system being below a threshold temperature, causing, by the controller, the engine to provide hydrocarbons, the preheating oxidation catalyst being configured to catalyze combustion of the hydrocarbons so as to increase the temperature of the exhaust gas to be above the threshold temperature.

12 . The method as claimed in claim 11 , wherein the controller causes the engine to provide the hydrocarbons in response to a temperature of the exhaust gas being greater than a light off temperature of the preheating oxidation catalyst.

13 . The method as claimed in claim 12 , wherein the aftertreatment system further comprises a heater operatively coupled to the preheating oxidation catalyst, and wherein the method further comprises:
causing activation of the heater, by the controller, in response to the temperature of the exhaust gas being less than the light off temperature of the preheating oxidation catalyst.

14 . The method as claimed in claim 11 , further comprising:
in response to the temperature of the exhaust gas reaching a light off temperature of the primary oxidation catalyst but still being below the threshold temperature, causing, by the controller, a hydrocarbon injector disposed between the preheating oxidation catalyst and the primary oxidation catalyst to insert second hydrocarbons.

15 . The method as claimed in claim 11 , further comprising:
in response to the temperature of the selective catalytic reduction system increasing to be equal to or greater than an upper threshold temperature that is greater than the threshold temperature, causing, by the controller, the engine to stop providing of the hydrocarbons.

16 . A controller for controlling operations of a system that comprises an engine and an aftertreatment system that includes, a preheating oxidation catalyst, a primary oxidation catalyst disposed downstream of the preheating oxidation catalyst, and a selective catalytic reduction system disposed downstream of the primary oxidation catalyst, the controller configured to:
determine a temperature of the exhaust gas at an inlet of the selective catalytic reduction system; and in response to the temperature of the exhaust gas at the inlet of the selective catalytic reduction system being below a threshold temperature, cause the engine to provide hydrocarbons, the preheating oxidation catalyst being configured to catalyze combustion of the hydrocarbons so as to increase the temperature of the exhaust gas to above the threshold temperature.

17 . The controller as claimed in claim 16 , wherein the controller causes the engine to provide the hydrocarbons in response to a temperature of the exhaust gas being greater than a light off temperature of the preheating oxidation catalyst.

18 . The controller as claimed in claim 17 , wherein the aftertreatment system further comprises a heater operatively coupled to the preheating oxidation catalyst, and wherein the controller is further configured to:
selectively activate the heater in response to the temperature of the exhaust gas being less than the light off temperature of the preheating oxidation catalyst.

19 . The controller as claimed in claim 17 , further configured to:
in response to the temperature of the exhaust gas reaching a light off temperature of the primary oxidation catalyst but still being below the threshold temperature, cause a hydrocarbon injector disposed between the preheating oxidation catalyst and the primary oxidation catalyst to insert seco

Assignees

• Cummins Emission Solutions Inc

Inventors

• Punde Shirish S
• Dabhoiwala Rayomand
• Reynolds James Nicholas

Classifications

• F01N2900/0602

  Electrical exhaust heater signals · CPC title

• B01D2251/208

  Hydrocarbons · CPC title

• B01D2251/2067

  Urea · CPC title

• B01D53/9495

  Controlling the catalytic process · CPC title

• B01D53/9477

  with catalysts positioned on separate bricks, e.g. exhaust systems · CPC title