CN-116733576-B - System and method for controlling regeneration of an aftertreatment system including a plurality of branches

Abstract

The present application relates to a system and method for controlling regeneration of an aftertreatment system including a plurality of branches. A controller for controlling regeneration in an aftertreatment system including a first leg and a second leg is configured to determine whether the engine is permitted to regenerate based on engine operating parameters, determine whether regeneration is required in at least one of the first leg or the second leg and whether regeneration is inhibited in the first leg or the second leg based on the operating parameters of the first leg and the second leg in response to the regeneration being permitted, and cause hydrocarbons to be introduced into the engine to raise the temperature of the exhaust gas to a target temperature and cause regeneration in each of the first leg and the second leg in response to the determination that regeneration is not inhibited in either the first leg or the second leg (i).

Inventors

• Vikram sandarajan
• GONG JINQIAN
• Daniel D. William
• Vijay Ramchandra Kadam
• WANG KERANG
• Todd A. Corbett

Assignees

• 康明斯排放处理公司

Dates

Publication Date

20260508

Application Date

20230306

Priority Date

20220310

Claims (18)

1. 1. A controller for controlling regeneration of at least one of a selective catalytic reduction catalyst or a filter included in a first leg or a second leg of an aftertreatment system, the first leg configured to receive a first portion of exhaust gas produced by an engine and the second leg configured to receive a second portion of the exhaust gas, the controller configured to: determining whether the engine allows regeneration based on engine operating parameters; In response to determining that the engine is permitted to regenerate, determining whether regeneration is required in at least one of the first leg or the second leg and whether regeneration is inhibited in the first leg or the second leg based on operating parameters of the first leg and the second leg; In response to determining that (i) regeneration is required in at least one of the first leg or the second leg and (ii) regeneration is not inhibited in the first leg or the second leg, causing hydrocarbon to be introduced into the engine, thereby raising the temperature of the exhaust gas to a target temperature and causing regeneration in each of the first leg and the second leg; monitoring the regeneration phase of each of the first and second branches, and In response to each of the first and second legs being in a regeneration phase corresponding to a plateau or in a regeneration phase occurring prior to the plateau, the target temperature is set to the lesser of a first target temperature of exhaust gas flowing through the first leg and a second target temperature of exhaust gas flowing through the second leg.
2. 2. The controller of claim 1, further configured to abort regeneration in response to determining that the engine does not allow regeneration.
3. 3. The controller of claim 1, further configured to abort regeneration in response to determining that regeneration in either of the first leg or the second leg is inhibited.
4. 4. The controller of claim 1, further configured to: in response to determining that regeneration is complete on each of the first and second legs based on the monitored regeneration phases, ceasing to cause hydrocarbon introduction into the engine.
5. 5. The controller of claim 1, further configured to raise the target temperature to a regulated target temperature greater than the smaller of the first target temperature and the second target temperature in response to one of the first leg or the second leg being in a regeneration phase occurring before the plateau and the other of the first leg or the second leg being in a regeneration phase occurring after the plateau.
6. 6. The controller of claim 5, further configured to: Determining whether one of the first leg or the second leg in a regeneration phase occurring prior to the plateau has reached the plateau, and In response to determining that the one of the first leg or the second leg has reached the plateau, maintaining the target temperature of the exhaust gas at the adjusted target temperature until the plateau of the one of the first leg or the second leg is completed.
7. 7. The controller of claim 6, further configured to set the target temperature to a lesser of the first target temperature and the second target temperature in response to each of the first and second legs being in a regeneration phase that occurs after the plateau or an actual temperature of exhaust gas in each of the first and second legs being greater than the regulated target temperature.
8. 8. The controller of claim 1, further configured to: Receiving a first feedback temperature signal from a temperature sensor in the first branch and a second feedback temperature signal from a temperature sensor in the second branch to determine a first feedback temperature of the first branch and a second feedback temperature of the second branch, respectively, and In response to determining that each of the first and second branches is in a regeneration phase that occurs before a target regeneration phase of each of the first and second branches, controlling an amount of hydrocarbon introduced into the engine using the greater of the first and second feedback temperatures to raise a temperature of the exhaust gas to the target temperature.
9. 9. The controller of claim 8, further configured to control an amount of hydrocarbon introduced into the engine to raise a temperature of the exhaust gas to the target temperature using an average of the first feedback temperature and the second feedback temperature in response to determining that either (i) at least one of the first leg or the second leg is at the target regeneration stage or is at a regeneration stage that occurs after the target regeneration stage and (ii) none of the first feedback temperature or the second feedback temperature remains above the target temperature for a first period of time.
10. 10. The controller of claim 8, further configured to control an amount of hydrocarbon introduced into the engine to raise a temperature of the exhaust gas to the target temperature using a weighted average of the first feedback temperature and the second feedback temperature in response to determining that (i) at least one of the first leg or the second leg is at the target regeneration stage or at a regeneration stage occurring after the target regeneration stage and (ii) one of the first feedback temperature or the second feedback temperature remains above the target temperature for a first period of time.
11. 11. The controller of any of claims 1-10, further configured to: determining an oxidation catalyst inlet temperature at an inlet of an oxidation catalyst included in each of the first and second legs of the aftertreatment system; Determining whether an estimated hydrocarbon ration of hydrocarbons to be introduced into the engine is less than a first branch hydrocarbon leakage limit of the first branch and a second branch hydrocarbon leakage limit of the second branch in response to the oxidation catalyst inlet temperature of each of the first branch and the second branch of the aftertreatment system being greater than a light-off temperature, and In response to the estimated hydrocarbon ration being less than each of the first and second branch hydrocarbon leakage limits, a hydrocarbon ration of hydrocarbon to be dosed into the engine is set to the estimated hydrocarbon ration.
12. 12. The controller of claim 11, further configured to: Determining whether the first branch hydrocarbon leak limit is greater than the second branch hydrocarbon leak limit in response to determining that the estimated hydrocarbon ration is greater than each of the first branch hydrocarbon leak limit and the second branch hydrocarbon leak limit, and Setting the second branch hydrocarbon leak limit to the hydrocarbon ration in response to the first branch hydrocarbon leak limit being greater than the second branch hydrocarbon leak limit, or In response to the first branch hydrocarbon leak limit being less than the second branch hydrocarbon leak limit, the first branch hydrocarbon leak limit is set to the hydrocarbon ration.
13. 13. An aftertreatment system, comprising: A first branch coupled to an engine and configured to receive a first portion of exhaust gas generated by the engine and a second branch coupled to the engine and configured to receive a second portion of the exhaust gas generated by the engine, each of the first and second branches comprising: -a selective catalytic reduction catalyst, -A filter arranged upstream of the selective catalytic reduction catalyst, and An oxidation catalyst arranged upstream of the filter, and The controller of any one of claims 1-12, coupled to a sensor included in each of the first and second branches.
14. 14. A method for controlling regeneration of at least one of a selective catalytic reduction catalyst or filter included in a first leg or a second leg of an aftertreatment system, the first leg configured to receive a first portion of exhaust gas produced by an engine and the second leg configured to receive a second portion of the exhaust gas, the method comprising: determining, by a controller coupled to each of the first and second branches of the aftertreatment system, whether the engine is permitted to regenerate based on engine operating parameters; Determining, by the controller, whether regeneration is required in at least one of the first leg or the second leg and whether regeneration is inhibited in the first leg or the second leg based on operating parameters of the first leg and the second leg in response to determining, by the controller, that the engine allows regeneration; In response to determining by the controller that (i) regeneration is required in at least one of the first leg or the second leg and (ii) regeneration is not inhibited in the first leg or the second leg, causing, by the controller, hydrocarbon to be introduced into the engine, thereby raising the temperature of the exhaust gas to a target temperature and causing regeneration in each of the first leg and the second leg; Monitoring, by the controller, a regeneration phase of each of the first and second legs, and The target temperature is set by the controller to be the smaller of a first target temperature of exhaust gas flowing through the first leg and a second target temperature of exhaust gas flowing through the second leg in response to each of the first leg and the second leg being in a regeneration phase corresponding to a plateau or in a regeneration phase occurring before the plateau.
15. 15. The method of claim 14, further comprising: In response to determining, by the controller, that regeneration is complete on each of the first and second legs based on the monitored regeneration phases, stopping, by the controller, introduction of hydrocarbons into the engine to stop regeneration in each of the first and second legs.
16. 16. The method of claim 14, further comprising increasing, by the controller, the target temperature to a regulated target temperature in response to one of the first leg or the second leg being in a regeneration phase that occurs prior to the plateau and the other of the first leg or the second leg being in a regeneration phase that occurs in the plateau.
17. 17. The method of claim 14, further comprising: determining, by the controller, a first feedback temperature of the first leg and a second feedback temperature of the second leg, and In response to determining, by the controller, that each of the first and second legs is in a regeneration phase that occurs prior to a target regeneration phase of each of the first and second legs, controlling, by the controller, an amount of hydrocarbon introduced into the engine using a greater one of the first and second feedback temperatures to raise a temperature of the exhaust gas to the target temperature.
18. 18. The method of any of claims 14-17, further comprising: determining, by the controller, an oxidation catalyst inlet temperature at an inlet of an oxidation catalyst included in each of the first and second legs of the aftertreatment system; Determining, by the controller, whether an estimated hydrocarbon ration of hydrocarbons to be introduced into the engine is less than a first branch hydrocarbon leakage limit of the first branch and a second branch hydrocarbon leakage limit of the second branch in response to the oxidation catalyst inlet temperature of each of the first branch and the second branch of the aftertreatment system being greater than a light-off temperature, and In response to the estimated hydrocarbon ration being less than each of the first and second branch hydrocarbon leakage limits, a hydrocarbon ration of hydrocarbon to be dosed into the engine is set to the estimated hydrocarbon ration.

Description

System and method for controlling regeneration of an aftertreatment system including a plurality of branches Technical Field The present disclosure relates generally to aftertreatment systems for use with Internal Combustion (IC) engines. Background An exhaust aftertreatment system is used to receive and treat exhaust gases produced by an engine, such as an internal combustion engine. Conventional exhaust gas aftertreatment systems include any one of several different components to reduce the level of harmful emissions present in the exhaust gas. For example, certain exhaust aftertreatment systems for diesel powered internal combustion engines include a Selective Catalytic Reduction (SCR) catalyst that is prepared to convert NOx (a proportion of NO and NO 2) to harmless nitrogen (N 2) and water vapor (H 2 O) in the presence of ammonia (NH 3). Typically, a reducing agent, such as a diesel exhaust fluid (e.g., an aqueous urea solution), is introduced into the aftertreatment system as a source of ammonia. The reductant helps to decompose the constituents of the exhaust gas through the SCR catalyst. During use, the reductant may be deposited on the SCR catalyst. Over time, reductant deposits may accumulate and result in a decrease in SCR catalytic Conversion Efficiency (CE) of the SCR catalyst. Heat may be requested from the engine to heat the exhaust gas to remove reductant deposits and regenerate the SCR catalyst. In addition, filters included in the aftertreatment system may also be plugged with particulate matter and may also be regenerated during the regeneration process. Some aftertreatment systems include two or more branches (legs), each including various components of the aftertreatment system. The exhaust gas produced by the engine is split into portions that flow into each branch of the aftertreatment system. Conventional aftertreatment systems introduce hydrocarbons into each leg of the aftertreatment system to cause regeneration. While this allows for independent control of regeneration of each branch, such an aftertreatment system may increase hardware requirements. Disclosure of Invention Embodiments described herein relate generally to systems and methods for regeneration in an aftertreatment system including first and second legs, and in particular, to an aftertreatment system including a controller configured to determine whether an SCR catalyst and/or filter disposed in either of the first or second legs of the aftertreatment system requires regeneration, and initiate regeneration in each of the first and second legs to cause regeneration in each leg when regeneration is requested by one of the legs, and to stop regeneration once each leg has completed regeneration. In some embodiments, a controller is configured to control regeneration of at least one of an SCR catalyst or filter included in a first leg or a second leg of an aftertreatment system, the first leg configured to receive a first portion of exhaust gas produced by an engine and the second leg configured to receive a second portion of the exhaust gas, the controller configured to determine whether the engine is allowed to regenerate based on engine operating parameters, determine whether regeneration is required in at least one of the first leg or the second leg and whether regeneration is inhibited in the first leg or the second leg based on the operating parameters of the first leg and the second leg in response to determining that (i) regeneration is required in at least one of the first leg or the second leg and (ii) regeneration is not inhibited in the first leg or the second leg, cause hydrocarbons to be introduced into the engine to raise a temperature of the exhaust gas to a target temperature and cause regeneration in each of the first leg and the second leg. In some embodiments, a method for controlling regeneration of at least one of an SCR catalyst or filter included in a first leg or a second leg of an aftertreatment system, the first leg configured to receive a first portion of exhaust gas produced by an engine and the second leg configured to receive a second portion of the exhaust gas, includes determining, by a controller coupled to each of the first leg and the second leg of the aftertreatment system, whether the engine is allowed to regenerate based on engine operating parameters, determining, by the controller, whether regeneration is required in at least one of the first leg or the second leg and whether regeneration is prohibited in the first leg or the second leg based on operating parameters of the first leg and the second leg, and in response to determining, by the controller, that regeneration is not prohibited in at least one of the first leg or the second leg, causing, by the controller, hydrocarbon to be introduced into the engine, thereby increasing a temperature of the exhaust gas to a target temperature and causing regeneration in each of the first leg and the second leg. The application also provide