System and method for controlling regeneration of a post-processing system comprising multiple branches

Abstract

The present application relates to systems and methods for controlling regeneration of an aftertreatment system including multiple branches. A controller for controlling regeneration in an aftertreatment system including a first branch and a second branch is configured to: determine whether regeneration is allowed by an engine based on engine operating parameters; in response to regeneration being allowed, determine whether regeneration is required in at least one of the first branch or the second branch and whether regeneration is prohibited in the first branch or the second branch based on operating parameters of the first branch and the second branch; and in response to determining (i) that regeneration is required in at least one of the first branch or the second branch and (ii) that regeneration is not prohibited in the first branch or the second branch, cause introduction of a hydrocarbon to the engine to raise a temperature of exhaust gas to a target temperature and cause regeneration in each of the first branch and the second branch.

Description

Technical Field

[0001] This disclosure generally relates to aftertreatment systems for use with internal combustion (IC) engines. Background Technology

[0002] Emission aftertreatment systems are used to receive and treat exhaust gases produced by engines such as internal combustion engines. Conventional emission aftertreatment systems include any of several different components to reduce the levels of harmful emissions present in the exhaust gases. For example, some emission aftertreatment systems for diesel-powered internal combustion engines include a selective catalytic reduction (SCR) catalyst, which is designed to convert NOx (a mixture of NO and NO2 in a specific ratio) into harmless nitrogen (N2) and water vapor (H2O) in the presence of ammonia (NH3).

[0003] Typically, a reducing agent (such as diesel exhaust fluid, e.g., an aqueous urea solution) is introduced into the aftertreatment system as an ammonia source. Through the SCR catalyst, the reducing agent helps to break down the components of the exhaust gases. During use, the reducing agent can deposit on the SCR catalyst. Over time, these deposits accumulate and lead to a decrease in the SCR catalytic conversion efficiency (CE) of the SCR catalyst. Heat can be requested from the engine to heat the exhaust gases, removing the reducing agent deposits and regenerating the SCR catalyst. Furthermore, filters included in the aftertreatment system can also become clogged with particulate matter and can also be regenerated during the regeneration process.

[0004] Some aftertreatment systems include two or more legs, each containing various components of the aftertreatment system. The exhaust gases produced by the engine are divided and flow into each leg of the aftertreatment system. Conventional aftertreatment systems introduce hydrocarbons into each leg to induce regeneration. While this allows for independent control of the regeneration in each leg, such aftertreatment systems can increase hardware requirements. Summary of the Invention

[0005] The embodiments described herein generally relate to systems and methods for regeneration in an aftertreatment system including a first branch and a second branch, and more specifically, to an aftertreatment system including a controller configured to determine whether an SCR catalyst and / or filter disposed in either the first or second branch of the aftertreatment system requires regeneration, and to initiate regeneration in each of the first and second branches to cause regeneration in each branch when regeneration is requested in one branch, and to stop regeneration once each branch has completed regeneration.

[0006] In some embodiments, a controller is used to control the regeneration of at least one of an SCR catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of exhaust gases. The controller is configured to: determine whether engine regeneration is permitted based on engine operating parameters; in response to determining that engine regeneration is permitted, determine whether regeneration is required in at least one of the first branch or the second branch, and whether regeneration is prohibited in the first branch or the second branch, based on operating parameters of the first branch and the second branch; and in response to determining (i) that regeneration is required in at least one of the first branch or the second branch and (ii) that regeneration is not prohibited in the first branch or the second branch, cause hydrocarbons to be introduced into the engine, thereby raising the temperature of the exhaust gases to a target temperature and causing regeneration in each of the first branch and the second branch.

[0007] In some embodiments, a method for controlling the regeneration of at least one of an SCR catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of the exhaust gases, the method comprising: determining, based on engine operating parameters, whether engine regeneration is permitted by a controller coupled to each of the first and second branches of the aftertreatment system; in response to the controller determining that engine regeneration is permitted, determining, based on the operating parameters of the first and second branches, whether regeneration is required in at least one of the first and second branches, and whether regeneration is prohibited in the first and second branches; and in response to the controller determining (i) that regeneration is required in at least one of the first and second branches and (ii) that regeneration is not prohibited in the first and second branches, inducing hydrocarbons to be introduced into the engine by the controller, thereby raising the temperature of the exhaust gases to a target temperature and inducing regeneration in each of the first and second branches.

[0008] This application also provides the following aspects:

[0009] 1) A controller for controlling the regeneration of at least one of a selective catalytic reduction catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of the exhaust gases, the controller being configured to:

[0010] Determine whether the engine is allowed to regenerate based on the engine's operating parameters;

[0011] In response to determining that the engine is permissible to regenerate, based on the operating parameters of the first branch and the second branch, it is determined whether regeneration is required in at least one of the first branch or the second branch, and whether regeneration is prohibited in the first branch or the second branch; and

[0012] In response to determining that (i) regeneration is required in at least one of the first branch or the second branch and (ii) regeneration is not prohibited in the first branch or the second branch, hydrocarbons are introduced into the engine, thereby raising the temperature of the exhaust gas to a target temperature and causing regeneration in each of the first branch and the second branch.

[0013] 2). The controller according to 1) is also configured to abort regeneration in response to determining that the engine is not allowed to regenerate.

[0014] 3) The controller according to 1) is further configured to abort regeneration in response to determining that regeneration in either the first branch or the second branch is prohibited.

[0015] 4). The controller according to 1) is further configured to:

[0016] Monitor the regeneration stage of each of the first branch and the second branch; and

[0017] In response to determining that regeneration is complete on each of the first and second branches based on the monitored regeneration stage, the introduction of hydrocarbons into the engine is stopped.

[0018] 5) The controller according to any one of 1)-4) is further configured to:

[0019] Monitor the regeneration stage of each of the first branch and the second branch; and

[0020] In response to each of the first branch and the second branch being in a regeneration phase corresponding to a steady phase or in a regeneration phase occurring before said steady phase, the target temperature is set to the smaller of a first target temperature of the exhaust gas flowing through the first branch and a second target temperature of the exhaust gas flowing through the second branch.

[0021] 6) The controller according to 5) is further configured to, in response to a regeneration phase occurring before the steady-state phase in one of the first branch or the second branch and a regeneration phase occurring after the steady-state phase in the other of the first branch or the second branch, raise the target temperature to an adjusted target temperature greater than the smaller of the first target temperature and the second target temperature.

[0022] 7). The controller according to 6) is further configured to:

[0023] Determine whether a branch in the first or second branch that is in a regeneration phase following the said steady phase has reached the said steady phase; and

[0024] In response to determining that one of the first or second branches has reached the steady-state phase, the target temperature of the exhaust gas is maintained at the adjusted target temperature until the steady-state phase of one of the first or second branches is completed.

[0025] 8) The controller according to 7) is further configured to set the target temperature to the smaller of the first target temperature and the second target temperature in response to a regeneration phase occurring after the steady-state phase in each of the first branch and the second branch, or to a greater than the regulated target temperature in each of the first branch and the second branch.

[0026] 9). The controller according to 5) is further configured to:

[0027] Receive 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 the first feedback temperature of the first branch and the second feedback temperature of the second branch, respectively; and

[0028] In response to determining that each of the first branch and the second branch is in a regeneration phase that occurs prior to a target regeneration phase in each of the first branch and the second branch, the greater of the first feedback temperature and the second feedback temperature is used to control the amount of hydrocarbons introduced into the engine so that the temperature of the exhaust gas is raised to the target temperature.

[0029] 10) The controller according to 9) is further configured to, in response to determining (i) at least one of the first branch or the second branch is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase and (ii) neither of the first feedback temperature nor the second feedback temperature remains above the target temperature for a first time period, use the average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine so that the temperature of the exhaust gas rises to the target temperature.

[0030] 11) The controller according to 9) is further configured to, in response to determining (i) at least one of the first branch or the second branch is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase and (ii) one of the first feedback temperature or the second feedback temperature remains above the target temperature for a first time period, use a weighted average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine so as to raise the temperature of the exhaust gas to the target temperature.

[0031] 12). The controller according to any one of 1)-4) and 6)-11) is further configured to:

[0032] Determine the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst included in each of the first and second branches of the aftertreatment system;

[0033] In response to the oxidation catalyst inlet temperature of each of the first and second branches of the aftertreatment system being greater than the ignition temperature, it is determined whether the estimated hydrocarbon allowance to be introduced into the engine is less than the hydrocarbon leakage limit of the first branch of the first branch and the hydrocarbon leakage limit of the second branch of the second branch; and

[0034] In response to the estimated hydrocarbon supply being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit, the hydrocarbon supply amount to be supplied to the engine is set to the estimated hydrocarbon supply amount.

[0035] 13). The controller according to 12) is further configured to:

[0036] In response to determining that the estimated hydrocarbon supply is greater than each of the hydrocarbon leakage limits of the first branch and the second branch, determine whether the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch; and

[0037] In response to the fact that the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch, the hydrocarbon leakage limit of the second branch is set to the hydrocarbon supply amount, or

[0038] In response to the fact that the hydrocarbon leakage limit of the first branch is less than the hydrocarbon leakage limit of the second branch, the hydrocarbon leakage limit of the first branch is set as the hydrocarbon supply amount.

[0039] 14) A post-processing system, comprising:

[0040] A first branch and a second branch, the first branch being connected to the engine and configured to receive a first portion of the exhaust gases produced by the engine, and the second branch being connected to the engine and configured to receive a second portion of the exhaust gases produced by the engine, each of the first branch and the second branch comprising:

[0041] Selective catalytic reduction catalyst,

[0042] A filter is installed upstream of the selective catalytic reduction catalyst, and

[0043] An oxidation catalyst is disposed upstream of the filter; and

[0044] The controller according to any one of 1)-13) is coupled to a sensor included in each of the first branch and the second branch.

[0045] 15) A method for controlling the regeneration of at least one of a selective catalytic reduction catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of the exhaust gases, the method comprising:

[0046] The controller of each of the first and second branches connected to the after-processing system determines whether the engine is allowed to regenerate based on engine operating parameters;

[0047] In response to the controller determining that the engine is permitted to regenerate, the controller determines, based on the operating parameters of the first branch and the second branch, whether regeneration is required in at least one of the first branch or the second branch, and whether regeneration is prohibited in the first branch or the second branch; and

[0048] In response to the controller determining (i) that regeneration is required in at least one of the first branch or the second branch and (ii) that regeneration is not prohibited in the first branch or the second branch, the controller causes hydrocarbons 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 branch and the second branch.

[0049] 16). The method according to 15) further includes:

[0050] The controller monitors the regeneration phase of each of the first branch and the second branch; and

[0051] In response to the controller determining that regeneration is complete in each of the first and second branches based on the monitored regeneration stage, the controller stops introducing hydrocarbons into the engine to stop regeneration in each of the first and second branches.

[0052] 17). The method according to 15) further includes:

[0053] The controller monitors the regeneration phase of each of the first branch and the second branch; and

[0054] In response to each of the first branch and the second branch being in a regeneration phase corresponding to a steady phase or in a regeneration phase occurring before said steady phase, the controller sets the target temperature to the smaller of a first target temperature of the exhaust gas flowing through the first branch and a second target temperature of the exhaust gas flowing through the second branch.

[0055] 18) The method according to 17) further includes, in response to a regeneration phase occurring before the steady-state phase in one of the first branch or the second branch and a regeneration phase occurring during the steady-state phase in the other of the first branch or the second branch, the controller raises the target temperature to the regulated target temperature.

[0056] 19) The method according to 17) further includes:

[0057] The controller determines the first feedback temperature of the first branch and the second feedback temperature of the second branch; and

[0058] In response to the controller determining that each of the first branch and the second branch is in a regeneration phase that occurs prior to a target regeneration phase for each of the first branch and the second branch, the controller uses the larger of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine so that the temperature of the exhaust gas rises to the target temperature.

[0059] 20) The method according to any one of 15)-19) further includes:

[0060] The controller determines the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst included in each of the first and second branches of the aftertreatment system;

[0061] In response to the oxidation catalyst inlet temperature of each of the first and second branches of the aftertreatment system being greater than the ignition temperature, the controller determines whether the estimated hydrocarbon allowance to be introduced into the engine is less than the hydrocarbon leakage limit of the first branch of the first branch and the hydrocarbon leakage limit of the second branch of the second branch; and

[0062] In response to the estimated hydrocarbon supply being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit, the hydrocarbon supply amount to be supplied to the engine is set to the estimated hydrocarbon supply amount.

[0063] It should be understood that all combinations of the foregoing concepts and the additional concepts discussed in more detail below (provided that these concepts are not contradictory) are considered part of the subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered part of the subject matter disclosed herein. Attached Figure Description

[0064] The foregoing and other features of this disclosure will become more apparent from the following description and appended claims in conjunction with the accompanying drawings. It is to be understood that these drawings depict only a few embodiments according to this disclosure and are therefore not intended to limit its scope; the disclosure will be described with additional features and details using the drawings.

[0065] Figure 1 This is a schematic diagram of a post-processing system according to an embodiment.

[0066] Figure 2 This is a block diagram of a controller according to an embodiment, which may be included in Figure 1 In the post-processing system.

[0067] Figure 3 This is a schematic flowchart of a method for initiating regeneration in a post-processing system including a first branch and a second branch, according to an embodiment.

[0068] Figure 4 It is according to the embodiment for use in Figure 3 A schematic flowchart of the method for determining and setting the target temperature to which the branch is heated.

[0069] Figure 5 This is a schematic flowchart of a method for determining a feedback temperature according to an embodiment, the feedback temperature being used to control via... Figure 3 The regeneration is performed using the method described above.

[0070] Figure 6This is according to an embodiment for setting the hydrocarbon dosage to be delivered via Figure 3 A schematic flowchart of a method for preventing hydrocarbon leakage through each branch of the aftertreatment system during regeneration.

[0071] Figure 7A yes Figure 1 A diagram showing the regeneration stages of the first and second branches of the post-processing system at different points in time, with each of the two branches experiencing various regeneration stages synchronously with each other. Figure 7B In the corresponding Figure 7A The regeneration phase during the regeneration period Figure 1 A graph showing the target temperature at different time points for each branch of the post-processing system; Figure 7C In the corresponding Figure 7A A graph showing the target temperature set by the controller during each regeneration stage of each branch.

[0072] Figure 8A yes Figure 1 A diagram showing the regeneration stages of the first and second branches of the post-processing system at different points in time, with each of the two branches experiencing various regeneration stages that are asynchronous with each other. Figure 8B In the corresponding Figure 8A The regeneration phase during the regeneration period Figure 1 A graph showing the target temperature at different time points for each branch of the post-processing system; Figure 8C In the corresponding Figure 8A A graph showing the target temperature set by the controller during each regeneration stage of each branch.

[0073] Figure 9 From Figure 1 A graph showing the actual feedback temperature received by the first and second branches of the post-processing system and the determined feedback temperature of the regeneration of each branch used to control the post-processing temperature.

[0074] Figure 10 This is a graph showing the hydrocarbon (HC) leakage limits of the first and second branches of the aftertreatment system according to an embodiment, the estimated HC allowance for achieving regeneration, and the final HC allowance introduced into the engine to induce regeneration in each branch of the aftertreatment system.

[0075] Figure 11 Is Figure 1 A graph showing the actual temperatures of the first and second branches of the post-processing system during the regeneration cycle, and the set target temperature for each branch.

[0076] In the following detailed description, reference is made to the accompanying drawings. In the drawings, similar symbols generally identify similar parts unless the context otherwise requires. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that, as generally described herein and illustrated in the drawings, various aspects of this disclosure can be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and are part of this disclosure. Detailed Implementation

[0077] The embodiments described herein generally relate to systems and methods for controlling regeneration in an aftertreatment system comprising a first branch and a second branch, and more specifically, to an aftertreatment system comprising a controller configured to determine whether an SCR catalyst and / or filter disposed in either the first or second branch of the aftertreatment system requires regeneration and to initiate regeneration in each of the first and second branches upon request of regeneration in one of the branches to cause regeneration in each branch and to stop regeneration once each branch has completed regeneration.

[0078] Some aftertreatment systems include two or more branches, each containing various components of the aftertreatment system. Exhaust gases produced by the engine are divided and flow into each branch of the aftertreatment system. Conventional aftertreatment systems introduce hydrocarbons into each branch to induce filter regeneration (i.e., heating to a temperature sufficient to remove particulate matter accumulated in the filter) and / or to induce regeneration of the SCR catalyst located in the corresponding branch of the aftertreatment system (i.e., heating to remove reductant deposits, particulate matter, or otherwise restore catalytic conversion efficiency). While this allows for independent control of regeneration in each branch, such aftertreatment systems can increase hardware requirements. For example, such aftertreatment systems typically include separate controllers for controlling the regeneration of the branches, and separate hydrocarbon introduction components for introducing hydrocarbons into the branches, thus increasing manufacturing costs and complexity.

[0079] In contrast, the aftertreatment system described herein achieves regeneration in each branch of the aftertreatment system by directly introducing hydrocarbons into the engine (e.g., by increasing the fuel-to-air ratio in the air / fuel mixture supplied to the engine). This results in the engine operating more reliably, thereby increasing the temperature of the exhaust gases and inducing regeneration in each branch of the aftertreatment system. While each branch of the aftertreatment system may require regeneration at different times and may have different regeneration needs, introducing hydrocarbons into the engine increases the temperature of the exhaust gases flowing into each branch, thus inducing regeneration in each branch of the aftertreatment system.

[0080] The embodiments of the systems and methods described herein for controlling regeneration in an aftertreatment system comprising a first branch and a second branch may provide one or more benefits, such as including: (1) reducing system complexity by using a single controller to control regeneration in each branch of the aftertreatment system; (2) eliminating the need for separate introduction components for introducing hydrocarbons into each branch, thereby reducing manufacturing complexity and cost; (3) ensuring that regeneration occurs when any branch requests regeneration to prevent a reduction in the catalytic conversion efficiency of the aftertreatment system; and (4) determining and setting target temperatures, feedback temperatures, and HC leakage limits to optimize regeneration in each branch while preventing hydrocarbon leakage.

[0081] As described herein, the term “regeneration in a branch” or variations thereof should be understood to refer to the regeneration of the SCR catalyst and / or filter (e.g., diesel particulate filter (DPF)) located in the corresponding branch of the aftertreatment system.

[0082] Figure 1 This is a schematic diagram of an aftertreatment system 100 coupled to engine 10 according to an embodiment. The aftertreatment system 100 includes a first branch 101a and a second branch 101b (e.g., two exhaust groups of the aftertreatment system 100), each of the first branch 101a and the second branch 101b being configured to receive a portion of the exhaust gases (e.g., diesel exhaust gases) produced by engine 10 and to process the components of the exhaust gases (e.g., NO). X The system treats CO and CO2. The aftertreatment system 100 includes a reducing agent storage tank 110, a reducing agent introduction assembly 120, a hydrocarbon introduction assembly 122, and a controller 170. Furthermore, the first branch 101a includes an SCR catalyst 150a, an oxidation catalyst 130a, a filter 140a, and optional ammonia oxidation (AMO) reactor. X The catalyst 160a and the second branch 101b include an SCR catalyst 150b, an oxidation catalyst 130b, a filter 140b, and an optional ammonia oxidation (AMO) catalyst. X Catalyst 160b.

[0083] For example, engine 10 may include a diesel engine, gasoline engine, natural gas engine, dual-fuel engine, biodiesel engine, E-85 engine, or any other suitable engine. Engine 10 burns fuel and produces NO. X The engine 10 emits exhaust gases containing CO, CO2, and other components. Engine controller 20 may be communicatively coupled to engine 10. Engine controller 20 is configured to receive information from engine sensor 24 to determine various engine parameters and control the operation of engine 10 (e.g., adjusting engine speed, engine torque, operating the engine in a lean or surplus operating mode, introducing hydrocarbons into engine 10, etc.). Such engine parameters may include, but are not limited to, at least one of the following: engine coolant temperature of engine 10, exhaust gas mass flow rate of exhaust gases produced by engine 10, engine torque of engine 10, engine speed of engine 10, or engine fault signals associated with engine 10 (e.g., engine fault codes). Although shown as a single sensor, engine sensor 24 may include a set of engine sensors, each configured to measure one or more engine parameters. In some embodiments, hydrocarbon introduction assembly 122 may be coupled to engine 10 and configured to introduce hydrocarbons into engine 10 to regulate the temperature of exhaust gases produced by engine 10 based on signals received from controller 170. In some embodiments, the hydrocarbon introduction component 122 may also be configured to introduce hydrocarbons into the aftertreatment system 100 upstream of the oxidation catalyst 130, which may also help to increase the temperature of the exhaust gases.

[0084] Branch lines 101a / 101b may include housings in which components of the post-processing system 100 are housed. The housings may be formed of rigid, heat-resistant, and corrosion-resistant materials (e.g., stainless steel, iron, aluminum, metal, ceramic, or any other suitable material). The housings may have any suitable cross-section, such as circular, square, rectangular, oval, elliptical, polygonal, or any other suitable shape.

[0085] The inlet conduit 102 is fluidly connected to the exhaust section of the engine 10 and configured to receive exhaust gas from the engine and divide it into a first portion delivered to a first branch 101a and a second portion delivered to a second branch 101b. Furthermore, the outlet conduit 104a can be connected to the outlet of the housing of the first branch 101a, and the outlet conduit 104b can be connected to the outlet of the housing of the second branch 101b. The outlet conduits 104a and 104b can be configured to discharge the treated first and second portions of the exhaust gas into the environment (e.g., by treatment with filters 140a / 140b to remove particulate matter such as soot, and / or by treatment with SCR catalysts 150a / 150b and oxidation catalysts 130a / 130b to reduce components in the exhaust gas, such as NO contained in the exhaust gas). X (Gas, CO, unburned hydrocarbons, etc.)

[0086] The first sensor 103 can be positioned within the inlet conduit 102. The first sensor 103 may include NO. X Sensor, NO X The sensor is configured to measure NO in the exhaust gas included in the inflow branches 101a / 101b. X The amount of gas, and the first sensor 103 may include physical sensors and / or virtual sensors. In various embodiments, temperature sensors, pressure sensors, oxygen sensors, or any other sensors may also be located in the inlet conduit 102 to determine one or more operating parameters of the exhaust gas flowing through the aftertreatment system 100.

[0087] A first oxidation catalyst inlet temperature sensor 106a is located at the inlet of oxidation catalyst 130a in the first branch 101a, and a second oxidation catalyst inlet temperature sensor 106b is located at the inlet of oxidation catalyst 130b in the second branch 101b. The first and second oxidation catalyst inlet temperature sensors 106a and 106b are configured to measure the feedback temperature at the inlets of oxidation catalysts 130a / 130b, respectively. The controller 170 can use the temperature of the exhaust gas supplied to the oxidation catalysts 130a / 130b to determine the required amount of thermal energy (e.g., associated with the amount of hydrocarbons to be supplied).

[0088] In some embodiments, controller 170 determines whether the temperature of the exhaust gas supplied to the first oxidation catalyst 130a is approximately equal to the temperature of the exhaust gas supplied to the second oxidation catalyst 130b. If the temperatures are approximately equal, the amount of heat energy is determined. If the temperatures are not approximately equal, controller 170 waits until the temperatures are approximately equal (e.g., regardless of whether the temperature measured by other sensors in the first branch 101a is equal to the temperature measured by the corresponding sensors in the second branch 101b, etc.) before determining the amount of heat energy.

[0089] The second sensor 105a / 105b can be located in the outlet conduit 104a / 104b of each branch 101a / 101b. The second sensor 105a / 105b may include a second NO. X Sensor, second NO X The sensor is configured to determine the amount of NOx gas emitted into the environment after passing through the SCR catalyst 150a / 150b. In other embodiments, the second sensor 105a / 105b may include a particulate matter sensor configured to determine the amount of particulate matter (e.g., soot included in the exhaust gas leaving the filter 140a / 140b) in the exhaust gas emitted into the environment. In still other embodiments, the second sensor 105a / 105b may include an ammonia sensor configured to measure the amount of ammonia in the exhaust gas exiting the SCR catalyst 150a / 150b, i.e., to determine an ammonia leak. This can be used as a measure of the catalytic conversion efficiency of the SCR catalyst 150a / 150b, to adjust the amount of reductant to be introduced into the SCR catalyst 150a / 150b, and / or to adjust the temperature of the SCR catalyst 150a / 150b so that the SCR catalyst 150a / 150b can effectively utilize ammonia to catalytically decompose NO contained in the exhaust gas flowing through the SCR catalyst. X Gas. AMO X Catalysts 160a / 160b can be located downstream of SCR catalysts 150a / 150b to decompose any unreacted ammonia in the exhaust gas downstream of SCR catalysts 150a / 150b.

[0090] Oxidation catalysts 130a / 130b may be located upstream of SCR catalysts 150a / 150b and configured to decompose unburned hydrocarbons and / or CO included in the exhaust gases. In some embodiments, oxidation catalysts 130a / 130b may include diesel oxidation catalysts. Oxidation catalysts 130a / 130b can catalyze the combustion of hydrocarbons (which may be included in the exhaust gases emitted by engine 10) (e.g., due to hydrocarbons being introduced into engine 10 by hydrocarbon introduction assembly 122), which increases the temperature of the exhaust gases. Heating the exhaust gases can be used to regenerate filters 140a / 140b by burning off particulate matter that may have accumulated on filters 140a / 140b, and / or to regenerate SCR catalysts 150a / 150b by evaporating reducing agent deposits deposited on SCR catalysts 150a / 150b. A first oxidation catalyst outlet temperature sensor 109a is disposed at the outlet of oxidation catalyst 130a in the first branch 101a, and a second oxidation catalyst outlet temperature sensor 109b is disposed at the outlet of oxidation catalyst 130b in the second branch 101b. The first and second oxidation catalyst outlet temperature sensors 109a and 109b are configured to measure the feedback temperature at the outlets of oxidation catalysts 130a and 130b, respectively. The first oxidation catalyst outlet temperature sensor 109a is also used to measure the feedback temperature at the inlet of the first filter 140a, and the second oxidation catalyst outlet temperature sensor 109b is also used to measure the feedback temperature at the inlet of the second filter 140b.

[0091] Filters 140a / 140b are disposed downstream of the respective oxidation catalysts 130a / 130b and upstream of the SCR catalysts 150a / 150b, and configured to remove particulate matter (e.g., soot, debris, inorganic particles, etc.) from the exhaust gas. In various embodiments, filters 140a / 140b may include ceramic filters. In some embodiments, filters 140a / 140b may include cordierite filters, which may be, for example, asymmetric filters. In other embodiments, filters 140a / 140b may be catalytic. In some embodiments, pressure sensors 107a / 107b may be disposed at the outlet of the respective filters 140a / 140b and configured to measure the filter outlet pressure at the outlet of the filters 140a / 140b. In other embodiments, pressure sensors 107a / 107b may include differential pressure sensors disposed across filters 140a / 140b and configured to measure the differential pressure across filters 140a / 140b. The filter outlet pressure or differential pressure can indicate the blockage of filters 140a / 140b and / or SCR catalysts 150a / 150b.

[0092] As described herein, SCR catalysts 150a / 150b are formulated to decompose components of exhaust gases flowing through the SCR catalyst in the presence of a reducing agent. In some embodiments, SCR catalysts 150a / 150b may include a selective catalytic reduction filter (SCRF). Any suitable SCR catalyst 150a or 150b may be used, such as platinum, palladium, rhodium, cerium, iron, manganese, copper, vanadium-based catalysts, any other suitable catalysts, or combinations thereof. SCR catalysts 150a / 150b may be disposed on a suitable substrate (e.g., a monolithic core such as ceramic (e.g., cordierite) or metal (e.g., kanthal)), which may, for example, define a honeycomb structure. A washcoat may also be used as a carrier material for the SCR catalysts 150a / 150b. Such a washcoat material may include, for example, alumina, titanium dioxide, silica, any other suitable washcoat material, or combinations thereof.

[0093] although Figure 1 Each of the first branch 101a and the second branch 101b is shown to include only oxidation catalysts 130a / 130b, filters 140a / 140b, SCR catalysts 150a / 150b, and AMO. X Catalyst 160a / 160b, but in other embodiments, in addition to oxidation catalyst 130a / 130b, filter 140a / 140b, SCR catalyst 150a / 150b and AMO X In addition to catalysts 160a / 160b, multiple aftertreatment components may be included in each branch 101a / 101b. Such aftertreatment components may include, for example, mixers, baffles, secondary filters (e.g., secondary split filters or catalytic filters) or any other suitable aftertreatment components.

[0094] Reductant ports 156a / 156b may be located on the sidewall of the housing of each branch 101a / 101b and configured to allow reductant to be introduced through them into the internal volume defined by the housing of each branch 101a / 101b. Reductant ports 156a / 156b may be located upstream of SCR catalysts 150a / 150b (e.g., allowing reductant to be introduced into exhaust gases upstream of SCR catalysts 150a / 150b) or above SCR catalysts 150a / 150b (e.g., allowing reductant to be introduced directly onto SCR catalysts 150a / 150b). In other embodiments, reductant ports 156a / 156b may be disposed on inlet conduit 102 and configured to introduce reductant into inlet conduit 102 upstream of SCR catalysts 150a / 150b. In such an embodiment, a mixer, baffle, blade, or other structure may be positioned in the inlet duct 102 to facilitate the mixing of the reducing agent with the exhaust gas.

[0095] The reducing agent storage tank 110 is configured to store a reducing agent. The reducing agent is formulated to promote the production of components that facilitate the emission of gases (e.g., NO contained in the emission gases). X The decomposition of gases. Any suitable reducing agent can be used. In some embodiments, the exhaust gases include diesel exhaust gases, and the reducing agent includes diesel exhaust fluid. For example, diesel exhaust fluid may include urea, an aqueous solution of urea, or any other fluid containing ammonia, byproducts, or any other diesel exhaust fluid known in the art (e.g., by name). (Diesel exhaust gas treatment fluid for sale). For example, the reducing agent may include an aqueous urea solution having a specific ratio of urea to water. In some embodiments, the reducing agent may comprise an aqueous urea solution comprising 32.5% urea and 67.5% deionized water by weight, comprising 40% urea and 60% deionized water by weight, or any other suitable ratio of urea to deionized water.

[0096] The reductant introduction assembly 120 is fluidly connected to the reductant storage tank 110. The reductant introduction assembly 120 is configured to selectively introduce reductant into the SCR catalyst 150a / 150b or upstream of it (e.g., into inlet conduit 102) or into a mixer (not shown) located upstream of the SCR catalyst 150a / 150b. The reductant introduction assembly 120 may include various structures, such as pumps, valves, screens, filters, etc., to facilitate receiving reductant from the reductant storage tank 110 and delivering reductant to the SCR catalyst 150a / 150b.

[0097] The aftertreatment system 100 may further include a reducing agent injector fluidly coupled to the reducing agent introduction assembly 120 and configured to introduce a reducing agent (e.g., a combined flow of reducing agent and compressed air) into the SCR catalyst 150a / 150b. In various embodiments, the reducing agent injector may include a nozzle having a predetermined diameter. In various embodiments, the reducing agent injector may be positioned in the reducing agent ports 156a / 156b and configured to deliver a flow or jet of reducing agent into the branch 101a / 101b to deliver the reducing agent to the SCR catalyst 150a / 150b.

[0098] Controller 170 is operatively coupled to reducing agent introduction assembly 120, hydrocarbon introduction assembly 122, first sensor 103, second sensors 105a / 105b, pressure sensors 107a / 107b, oxidation catalyst outlet temperature sensors 109a / 109b, and engine controller 20. Controller 170 is coupled to various sensors included in each of the first branch 101a and the second branch 101b to determine operating parameters of the first branch 101a and the second branch 101b. For example, controller 170 may be communicatively coupled to the first sensor 103 and may be configured to receive a first sensor signal from the first sensor 103, for example, to determine the amount of NO included in the exhaust gas entering the aftertreatment system 100. X The amount of gas, the inlet temperature of the oxidation catalyst 130a / 130b, or other parameters of the exhaust gas or aftertreatment system 100. The controller 170 can also be communicatively coupled to the second sensor 105a / 105b and can be configured to determine the amount of NO included in the exhaust gas discharged into the environment. X The concentration of the gas or ammonia, or other parameters of the emitted gas.

[0099] Controller 170 can be configured to be based on NO entering post-processing system 100. X NO gas inlet X The quantity and the NO leaving the first branch 101a and the second branch 101b X Gas outlet NO X The quantity is used to determine the SCR catalytic conversion efficiency of SCR catalysts 150a / 150b. For example, controller 170 can determine the inlet NO. X Volume and Export NO X The controller 170 calculates the difference between quantities and determines the SCR catalytic conversion efficiency of SCR catalysts 150a / 150b based on this difference. It also determines whether SCR catalysts 150a / 150b require regeneration (e.g., due to blockage by reductant deposits or denaturation of the catalyst active material) based on the SCR catalytic conversion efficiency. The controller 170 can also be coupled to pressure sensors 107a / 107b to receive pressure signals (e.g., corresponding to filter outlet pressure or differential pressure across filters 140a / 140b) and determine whether filters 140a or 140b require regeneration (e.g., regeneration is needed to remove blockages or unclog filters 140a / 140b). The controller 170 can also be coupled to oxidation catalyst outlet temperature sensors 109a / 109b to determine the feedback temperature at the outlet of oxidation catalysts 130a / 130b. The controller 170 can use this feedback temperature to set a target temperature to induce regeneration in each branch 101a / 101b.

[0100] The controller 170 can be operatively coupled to various components of the engine controller 20, the first sensor 103, the second sensors 105a / 105b, the pressure sensors 107a / 107b, the oxidation catalyst outlet temperature sensors 109a / 109b, the reductant introduction assembly 120, the hydrocarbon introduction assembly 122, and the aftertreatment system 100 using any type and any number of wired or wireless connections. For example, wired connections may include serial cables, fiber optic cables, CAT5 cables, or any other form of wired connection. Wireless connections may include the Internet, Wi-Fi, cellular, radio, Bluetooth, ZigBee, etc. In one embodiment, a controller local area network (CAN) bus provides the exchange of signals, information, and / or data. The CAN bus includes any number of wired and wireless connections.

[0101] like Figure 1 As shown, the exhaust gas from the engine is divided into a first portion flowing into a first branch 101a and a second portion flowing into a second branch 101b. In conventional aftertreatment systems, hydrocarbons are introduced independently into each branch of the aftertreatment system to regenerate each branch independently as needed. In contrast, the hydrocarbon introduction assembly 122 is configured to introduce hydrocarbons directly into the engine 10, which will cause an increase in the temperature of the exhaust gas discharged from the engine 10, thereby causing a temperature increase in each branch 101a / 101b of the aftertreatment system 100 due to both the first and second exhaust gas portions. The controller 170 is configured to trigger or initiate regeneration based on the operating conditions of each of the first and second branches 101a and 101b.

[0102] Further extending this, controller 170 is configured to determine whether engine 10 is permitted to regenerate based on engine operating parameters. For example, controller 170 may receive engine operating parameters from engine controller 20, which may be measured by engine sensor 24. Such engine parameters may include, but are not limited to, the engine coolant temperature of engine 10, the exhaust gas mass flow rate of exhaust gases produced by engine 10, engine torque of engine 10, engine speed of engine 10, or engine fault signals associated with engine 10 (e.g., engine fault codes), any other suitable parameters, or combinations thereof. For example, there may be certain conditions that prevent engine 10 from performing regeneration (e.g., excessive torque or load on the engine, engine idling, insufficient fuel, or engine operating parameters exceeding established thresholds). If controller 170 determines, for example, based on signals received from engine controller 20, that engine 10 is not permitted to regenerate, controller 170 may abort regeneration.

[0103] In response to determining that engine 10 is permitted to regenerate, controller 170 determines whether at least one of the first branch 101a or the second branch 101b requires regeneration based on operating parameters of the first branch 101a and the second branch 101b, and, for example, also determines whether regeneration in the first branch 101a or the second branch 101b is prohibited based on the operating parameters of the first branch 101a and the second branch 101b. Operating parameters of branches 101a / 101b may include the pressure at the outlet of filter 140a / 140b or the pressure across filter 140a / 140b, and NO at the second sensor 105a / 105b. x Conversion efficiency or temperature of SCR catalysts 150a / 150b, status of various sensors included in the aftertreatment system 100, etc. In this specification, the phrase "regeneration required" or variations thereof means that a threshold condition has been met, indicating that at least one of SCR catalysts 150a or 150b or at least one of filters 140a or 140b will benefit from regeneration.

[0104] In some embodiments, regeneration in the first branch 101a and / or the second branch 101b may be prohibited. For example, filters 140a / 140b or SCR catalysts 150a / 150b may have failed, sensors 105a / 105b, 107a / 107b, 109a / 109b or other sensors included in the aftertreatment system 100 may have malfunctioned, hydrocarbon introduction assembly 122 or its components may have malfunctioned, reductant introduction assembly 120 or its components may have malfunctioned, or other operating conditions may exist that prohibit regeneration (e.g., due to the possibility of damage to the aftertreatment components of the first branch 101a and / or the second branch 101b, or NO). X (Emissions exceed the permissible threshold). In this case, controller 170 stops regeneration.

[0105] Conversely, if controller 170 determines that (i) at least one of the first branch 101a or the second branch 101b requires regeneration and (ii) regeneration in the first branch 101a or the second branch 101b is not prohibited, controller 170 is configured to cause hydrocarbons to be introduced into engine 10, thereby raising the temperature of the exhaust gas to a target temperature, and causing regeneration in each of the first branch 101a and the second branch 101b. That is, once controller 170 determines that one of the first branch 101a or the second branch 101b requires regeneration, controller 170 may cause hydrocarbon introduction assembly 122 to be activated to introduce hydrocarbons into engine 10 (e.g., to allow engine 10 to run comfortably and exhaust heated exhaust gas). Therefore, even if only one of the branches 101a / 101b requests regeneration, regeneration is initiated in each of the branches 101a and 101b.

[0106] The controller 170 monitors the regeneration stage of each of the first branch 101a and the second branch 101b during regeneration, for example, based on feedback temperature received from the first sensor 103, the oxidation catalyst outlet temperature sensor 109a, or temperature signals received from any temperature sensor configured to measure the temperature of the SCR catalysts 150a / 150b. Figure 7A Various regeneration stages of the post-processing system 100 are shown, wherein the first branch 101a and the second branch 101b both experience the same regeneration stage at various time points (represented as x1, x2, x3, x4 and x5 on the x-axis).

[0107] The regeneration phase may include a preheating phase, in which the temperature of branches 101a / 101b is raised to a preheating temperature (e.g., 400-450 degrees Celsius for filter regeneration, 325-450 degrees Celsius for SCR catalyst regeneration); a stabilization phase, which occurs after the preheating phase, in which the temperature is maintained at the preheating temperature for a predetermined period of time (e.g., 30-60 seconds for filter regeneration, 20-60 seconds for SCR catalyst regeneration); and a target regeneration phase, which occurs after the stabilization phase, in which the temperature of the aftertreatment system 100 is increased to a target temperature (e.g., 500-575 degrees Celsius for filter regeneration, 350-575 degrees Celsius for SCR catalyst regeneration). These regeneration stages also include a regeneration stage that occurs after the target regeneration stage, in which the temperatures of branches 101a and 101b are maintained at or above the target temperature (e.g., within +10%) to induce regeneration in each branch 101a / 101b. The regeneration stages also include a conditioning stage that occurs after the target regeneration stage, in which the temperatures of branches 101a / 101b are reduced to their initial temperatures, i.e., the temperatures of branches 101a / 101b before the preheating stage begins. Figure 8A Another scenario is shown where the first branch 101 and the second branch 101b experience different regeneration stages at different times.

[0108] The controller 170 is configured to determine whether regeneration in each of the first branch 101a and the second branch 101b is complete. Once the controller 170 determines that regeneration in each of the first branch 101a and the second branch 101b is complete, the controller 170 stops introducing hydrocarbons into the engine 10 to stop regeneration in each of the first branch 101a and the second branch 101b.

[0109] The first branch 101a and the second branch 101b may require different regeneration processes, each corresponding to a different target temperature at which regeneration should be performed. For example, controller 170 may determine, based on the operating parameters of the first branch 101a, that the first branch 101a requires regeneration of the SCR catalyst 150a, which may correspond to a first target temperature (e.g., 450-500 degrees Celsius, 400-450 degrees Celsius). In contrast, controller 170 may determine, based on the operating parameters of the second branch 101b, that the second branch 101b requires regeneration of the filter 140b, which may correspond to a second target temperature (e.g., 525-575 degrees Celsius, 450-575 degrees Celsius), which may be lower than or otherwise different from the first target temperature. Therefore, regeneration in each branch 101a / 101b may require different target temperatures to meet its regeneration needs. Furthermore, as... Figure 8A As shown, each of the first branch 101a and the second branch 101b can undergo different regeneration stages at different times, and therefore, the target temperature of the first branch 101a can be different from the target temperature of the second branch 101b.

[0110] For example, if both the first branch 101a and the second branch 101b are used for filter regeneration, the first target temperature could be 450-500 degrees Celsius, and the second target temperature could be 525-575 degrees Celsius. In another example, if both the first branch 101a and the second branch 101b are used for filter regeneration, the first target temperature could be 400-450 degrees Celsius, and the second target temperature could be 450-575 degrees Celsius. Such examples may be useful when the second branch 101b is ending its plateau phase and the first branch 101a is preparing to continue from the plateau phase.

[0111] The controller 170 is configured to set a target temperature for controlling regeneration based on the target temperature of each of the first branch 101a and the second branch 101b. For example, the controller 170 may monitor the regeneration phase of each of the first branch 101a and the second branch 101b. In response to each of the first branch 101a and the second branch 101b being in a regeneration phase corresponding to a stable phase or a regeneration phase occurring after a stable phase, the controller 170 is configured to set the target temperature to the smaller of a first target temperature of the first branch 101a and a second target temperature of the second branch 101b. For example, if the second target temperature of the second branch 101b is less than the first target temperature of the first branch 101a, the controller sets the target temperature to the second target temperature.

[0112] However, in response to either the first branch 101a or the second branch 101b being in a regeneration phase occurring before a steady-state phase and the other branch 101b being in a regeneration phase occurring after a steady-state phase, the controller 170 is configured to cause the target temperature to increase to the regulated target temperature. For example, the first branch 101a may be in a steady-state phase or in a regeneration phase occurring after a steady-state phase, and the second branch 101b may be in a regeneration phase occurring before a steady-state phase. In this scenario, controller 170 can be configured to increase the temperature from the smaller of a first target temperature and a second target temperature (e.g., to a temperature higher than the second target temperature described in the example in the previous paragraph) to an adjusted target temperature greater than the smaller of the first target temperature and the second target temperature, for example, greater than the second target temperature, but also greater than the first target temperature, in order to accelerate the heating of the lagging branch (i.e., the branch 101a / 101b that lags behind in the regeneration phase) toward a steady-state phase, where, in the specific scenario described in the previous paragraph, the lagging branch is the second branch 101b.

[0113] The controller 170 can continue to monitor the regeneration phase of each branch 101a / 101b and determine whether one of the branches 101a or 101b that is in a regeneration phase preceding a steady-state phase has reached a steady-state phase. In response to determining that one of the branches 101a or 101b has reached a steady-state phase, the controller 170 is configured to maintain or sustain the target temperature at the regulated target temperature until the steady-state phase of the lagging branch 101a or 101b is completed.

[0114] In response to each of the first branch 101a and the second branch 101b being in a regeneration phase following a steady-state phase, or the actual temperature of each of the first branch 101a and the second branch 101b being greater than the adjusted target temperature, the controller 170 is configured to set the target temperature to the smaller of a first target temperature for the first branch 101a and a second target temperature for the second branch 101b. Conversely, even after a branch 101a or 101b lagging in its regeneration phase has completed its steady-state period but the actual temperature of both branches 101a / 101b is not greater than the adjusted target temperature, the controller 170 is configured to maintain or hold the target temperature at the adjusted target temperature until the actual temperature of both branches 101a / 101b (i.e., the feedback temperature received from the temperature sensor) is greater than the adjusted target temperature. It should be understood that the target temperature determined and set by the controller 170 is not a fixed value, but rather changes dynamically over time to allow each branch 101a / 101b of the post-processing system 100 to undergo various regeneration phases.

[0115] In some embodiments, the aftertreatment system 100 includes a first filter outlet temperature sensor 190a. The first filter outlet temperature sensor 190a is disposed at the outlet of the first filter 140a and configured to measure the feedback temperature at the outlet of the first filter 140a. The first filter outlet temperature sensor 190a is also configured to measure the feedback temperature at the inlet of the first SCR catalyst 150a. In some embodiments, the aftertreatment system 100 includes a second filter outlet temperature sensor 190b. The second filter outlet temperature sensor 190b is disposed at the outlet of the second filter 140b and configured to measure the feedback temperature at the outlet of the second filter 140b. The second filter outlet temperature sensor 190b is also configured to measure the feedback temperature at the inlet of the second SCR catalyst 150b. The filter outlet temperature sensors 190a / 190b are operatively coupled to a controller 170. If the feedback temperature is too high (e.g., above a threshold), the feedback temperature measured by the filter outlet temperature sensors 190a / 190b can be used to correct for a target temperature (e.g., by negative offset).

[0116] In some embodiments, the aftertreatment system 100 includes a first SCR catalyst outlet temperature sensor 191a. The first SCR catalyst outlet temperature sensor 191a is located at the outlet of the first SCR catalyst 150a and is configured to measure the feedback temperature at the outlet of the first SCR catalyst 150a. The first SCR catalyst outlet temperature sensor 191a is also configured to measure the first AMO... X The feedback temperature at the inlet of catalyst 160a. In some embodiments, the aftertreatment system 100 includes a second SCR catalyst outlet temperature sensor 191b. The second SCR catalyst outlet temperature sensor 191b is located at the outlet of the second SCR catalyst 150b and is configured to measure the feedback temperature at the outlet of the second SCR catalyst 150b. The second SCR catalyst outlet temperature sensor 191b is also configured to measure the second AMO X The feedback temperature at the inlet of catalyst 160b. SCR catalyst outlet temperature sensors 191a / 191b are operatively coupled to controller 170. If the feedback temperature is too high (e.g., above a threshold), the feedback temperature measured by SCR catalyst outlet temperature sensors 191a / 191b can be used to correct for the target temperature (e.g., by negative offset).

[0117] Figure 7B Corresponding to the first branch 101a and the second branch 101b simultaneously experiencing the same regeneration stage Figure 7A , Figure 7BThe first target temperature of the first branch 101a at different time points is shown, which is higher than the target temperature of the second branch 101b at the same time point. Figure 7C The final target temperature determined by the controller 170 at different time points is shown, along with the corresponding feedback temperature received from the second branch 101b, which is used to control the regeneration of each of the first branch 101a and the second branch 101b, and the corresponding feedback temperature corresponds to the measured temperature of the second branch 101b during various regeneration phases.

[0118] Figure 8B Corresponding to the first branch 101a and the second branch 101b experiencing different regeneration stages at different times Figure 8A , Figure 8B A graph showing the first target temperature of the first branch 101a and the second target temperature of the second branch 101b at various regeneration stages in each branch 101a / 101b is presented. Figure 8C This is a graph set by controller 170 to control the final regeneration target temperature for the regeneration of each of the two branches 101a / 101b. Up to time point x2, when the first branch 101a is still in its steady-state phase and the second branch 101b has not yet begun its steady-state phase, the target temperature is set by controller 170 to the smaller (or lesser) of a first target temperature and a second target temperature. Once the first branch 101a (which is the leading branch (i.e., experiences various regeneration phases earlier than the second branch 101b)) enters the target phase that occurs after the regeneration phase, controller 170 increases or raises the target temperature to the adjusted target temperature (e.g., as shown in the graph). Figure 8C The target temperature is 425 degrees Celsius (but could be any other regulated target temperature), and is maintained at this regulated target temperature until both branches 101a / 101b exit the target phase, and each of the first branch feedback temperature and the second branch feedback temperature is greater than the regulated target temperature. Then, the controller 170 sets the target temperature to the smaller of the first target temperature and the second target temperature.

[0119] Although controller 170 receives feedback temperatures from both branches 101a / 101b, such as the oxidation catalyst outlet temperature from oxidation catalyst outlet temperature sensors 109a / 109b, and uses these oxidation catalyst outlet temperatures to control or monitor regeneration in each branch 101a / 101b, in some cases the oxidation catalyst outlet temperatures received from the first branch 101a and the second branch 101b may be different. Controller 170 is configured to determine the feedback temperature for controlling regeneration based on each of a first feedback temperature received from the first branch 101a (e.g., the first oxidation catalyst outlet temperature received from oxidation catalyst outlet temperature sensor 109a) and a second feedback temperature received from the second branch 101b (e.g., the second oxidation catalyst outlet temperature received from the second oxidation catalyst outlet temperature sensor 109b).

[0120] For example, controller 170 may be configured to receive a first feedback temperature signal from first branch 101a and a second feedback temperature signal from second branch 101b to determine the first feedback temperature of first branch 101a and the second feedback temperature of second branch 101b, respectively. In response to determining that each of first branch 101a and second branch 101b is in a regeneration phase preceding their respective target regeneration phase, controller 170 is configured to use the larger of the first and second feedback temperatures to control the amount of hydrocarbons introduced into engine 10 to cause the temperature of the exhaust gases to rise to the target temperature.

[0121] On the other hand, if the controller determines that (i) at least one of the first branch 101a or the second branch 101b is in its target regeneration phase or in a regeneration phase that occurs after the target regeneration phase and (ii) neither the first feedback temperature nor the second feedback temperature remains above the target temperature during a first time period (e.g., 20-30 seconds), the controller 170 is configured to use the average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine 10 to cause the temperature of the exhaust gas to rise to the target temperature.

[0122] In some embodiments, the controller 170 includes temperature control that can shorten a first time period when the temperature of the first branch 101a or the second branch 101b is higher than a threshold temperature. The amount of hydrocarbons introduced into the engine 10 can be controlled based on a comparison between the temperature and the threshold temperature. For example, when the difference between the feedback temperature and the target threshold temperature is large, more hydrocarbons can be introduced. Conversely, when the outlet temperature of the first oxidation catalyst or the outlet temperature of the second oxidation catalyst is too high above the target temperature, less hydrocarbons are introduced.

[0123] However, if the controller determines that (i) at least one of the first branch 101a or the second branch 101b is in the target regeneration phase or in a regeneration phase that occurs after the target regeneration phase and (ii) one of the first feedback temperature or the second feedback temperature remains above the target temperature during a first time period, the controller 170 is configured to determine and use a weighted average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine 10 to cause the temperature of the exhaust gas to rise to the target temperature.

[0124] Figure 9 A graph showing the final feedback temperature determined by controller 170 based on the feedback temperatures of the first and second branches is illustrated. Up to time point x2, when both branches are in the regeneration phase occurring before the target regeneration phase, controller 170 uses the larger or maximum of the first and second branch feedback temperatures to control regeneration. Once either the first branch 101a or the second branch 101b is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase, controller 170 uses the average of the first and second branch feedback temperatures (indicated by...) Figure 9 Regeneration is controlled using a weighted average (represented as 50 / 50 weight). Once the controller 170 determines that the first branch feedback temperature remains above the target temperature during a first time period, the controller 170 determines and uses a weighted average of the first and second branch feedback temperatures to control regeneration. For example, in this case, since the first branch 101a is hotter than the second branch 101b, the weighted average is biased towards the first branch feedback temperature or weighted towards the first branch feedback temperature. This weighting or bias towards the hotter branch prevents either the first branch 101a or the second branch 101b from becoming too hot (which would damage the hotter branch).

[0125] The controller 170 is configured to determine the amount of hydrocarbons to be introduced into the engine 10 to achieve the target temperature based on the target final oxidation catalyst outlet temperature, which may correspond to the target temperature, the total exhaust gas flow rate, the average oxidation catalyst inlet temperature of the oxidation catalysts 130a / 130b (e.g., measured by the first sensor 103 or another temperature sensor located at the inlet of each oxidation catalyst 130a / 130b), and the average of the expected thermal efficiency of the filters 140a / 140b. The target final oxidation catalyst outlet temperature can be determined by the controller 170, as previously described herein. While the determined hydrocarbon feed rate is based on the target temperature, the actual temperature (i.e., the feedback temperature) of each branch 101a / 101b may differ from the target temperature. The controller 170 is also configured to determine an estimated hydrocarbon feed rate based on the determined amount of hydrocarbons to be introduced (based on the desired target temperature and the feedback temperature of each branch) [e.g., using a proportional-integral-derivative (PID) quantity determined by the proportional-integral-derivative (PID) quantity of the controller 170 or the feedback portion].

[0126] However, excessive hydrocarbon supply can lead to unburned hydrocarbon leakage downstream of oxidation catalysts 130a / 130b, which is undesirable. Therefore, the first branch 101a has a first hydrocarbon leakage limit or a first HC leakage limit, which corresponds to the maximum amount of hydrocarbon that can be introduced into the first branch 101a based on the feedback temperature of the first branch 101a without HC leakage, and the second branch 101b has a second HC leakage limit based on the maximum amount of hydrocarbon (which can be introduced into the second branch 101b based on the feedback temperature of the second branch 101b without hydrocarbon leakage).

[0127] Controller 170 determines whether the emission flow rate is greater than a flow threshold. If the emission flow rate is less than the flow threshold, controller 170 continues to monitor the emission flow rate. Once the emission flow rate is greater than the flow threshold, controller 170 determines the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst 130a included in the first branch 101a and the oxidation catalyst 130b included in the second branch 101b. If the oxidation catalyst inlet temperature of either oxidation catalyst 130a / 130b is lower than its corresponding ignition temperature, which corresponds to the minimum temperature at which oxidation catalyst 130a / 130b can catalyze the combustion of hydrocarbons, controller 170 sets the hydrocarbon introduction amount to zero, i.e., hydrocarbons are not introduced into engine 10 (except for those hydrocarbons introduced to perform normal engine operation), and regeneration is not initiated.

[0128] In response to the oxidation catalyst inlet temperature of each of the first branch 101a and the second branch 101b of the aftertreatment system 100 being greater than their respective ignition temperatures, the controller 170 determines whether the estimated hydrocarbon allowance to be introduced into the engine 10 is less than the first branch hydrocarbon leakage limit of the first branch and the second branch hydrocarbon leakage limit of the second branch. In response to the estimated hydrocarbon allowance being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit, the controller 170 sets the hydrocarbon allowance to be supplied to the engine 10 to the estimated hydrocarbon allowance.

[0129] On the other hand, in response to determining that the estimated hydrocarbon supply is greater than each of the hydrocarbon leakage limits of the first branch and the second branch, the controller 170 determines whether the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch. In response that the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch, the controller 170 sets the hydrocarbon leakage limit of the second branch as the hydrocarbon supply amount, and in response that the hydrocarbon leakage limit of the first branch is less than the hydrocarbon leakage limit of the second branch, the controller 170 sets the hydrocarbon leakage limit of the first branch as the hydrocarbon supply amount. Therefore, the controller 170 always selects the smaller of the first and second hydrocarbon leakage limits as the supply amount to prevent hydrocarbon leakage in both branches 101a / 101b.

[0130] Figure 10 This is a graph showing the hydrocarbon leakage limits of the first branch 101a and the second branch 101b, the estimated hydrocarbon feed rate, and the final estimated hydrocarbon feed rate introduced into the engine 10. The controller 170 does not initiate hydrocarbon feeding until time point x1, until the oxidation catalysts 130a / 130b reach their respective ignition temperatures. The controller 170 then controls the HC feed rate so that the final HC feed rate is always kept below the HC leakage limits of the first and second branches.

[0131] Figure 11 This is a graph showing the target temperature and actual temperature or feedback temperature received from each of the first branch 101a and the second branch 101b as each branch performs its respective regeneration stage during regeneration controlled by the controller 170 in the post-processing system 100. Figure 11As shown, the controller 170 simultaneously initiates regeneration in each branch 101a / 101b and dynamically adjusts the target temperature so that even if the regeneration between the two branches 101a / 101b may initially be asynchronous, the two branches 101a / 101b tend to request the same target temperature.

[0132] Controller 170 receives temperatures from various temperature sensors. In some cases, one or more temperature sensors may fail. In such cases, controller 170 uses temperature signals received from other temperature sensors instead of the failed sensor, or alternatively uses a default temperature value. For example, if the oxidation catalyst inlet temperature sensor fails, controller 170 can use the oxidation catalyst outlet temperature measured by the oxidation catalyst outlet temperature sensor (e.g., sensor 109a / 109b) when the oxidation catalyst outlet temperature sensor is functioning normally. In some embodiments, controller 170 can be configured to adjust the oxidation catalyst outlet temperature based on ambient temperature, and can adjust the oxidation catalyst outlet temperature only when hydrocarbons are not being introduced into oxidation catalyst 130a / 130b. However, if the oxidation catalyst outlet temperature sensor also malfunctions, controller 170 can alternatively use a default oxidation catalyst inlet temperature value stored in controller 170's memory.

[0133] If the oxidation catalyst outlet temperature sensor fails but the oxidation catalyst inlet temperature sensor (e.g., first sensor 103) is functioning normally, the controller 170 can use either the oxidation catalyst inlet temperature measured by the oxidation catalyst inlet temperature sensor or the filter outlet temperature at the outlet of filters 140a / 140b. If the filter outlet temperature sensor is functioning normally, the filter outlet temperature can be adjusted based on the ambient temperature. However, if both the oxidation catalyst inlet temperature sensor and the filter outlet temperature sensor malfunction, the controller 170 can instead use a default oxidation catalyst outlet temperature value stored in the controller 170's memory.

[0134] If the filter outlet temperature sensor fails but the oxidation catalyst outlet temperature sensor (e.g., sensor 109a / 109b) is functioning normally, the controller 170 can use the oxidation catalyst outlet temperature measured by the oxidation catalyst outlet temperature sensor. However, if the oxidation catalyst outlet temperature sensor also malfunctions, the controller 170 can instead use the default filter outlet temperature value stored in the controller 170's memory.

[0135] Generally, controller 170 can be configured to determine the SCR inlet temperature at the inlet of SCR catalyst 150a / 150b based on a weighted average between the filter outlet temperature measured by the filter outlet temperature sensor and the SCR inlet temperature measured by the SCR inlet temperature sensor. If the filter outlet temperature sensor fails, controller 170 can use only the SCR inlet temperature without calculating the weighted average.

[0136] If the SCR outlet temperature sensor fails, the controller 170 can be configured to use the default SCR outlet temperature value instead of the measured SCR outlet temperature.

[0137] In some embodiments, controller 170 includes various circuits or modules configured to perform the operation of controller 170 as described herein. For example, Figure 2 A block diagram of a controller 170 according to an embodiment is shown. The controller 170 may include a processor 172, a memory 174 or any other computer-readable medium, and a communication interface 176. Furthermore, the controller 170 includes a regeneration request determination module 174a, a regeneration trigger control module 174b, a target temperature determination module 174c, a feedback temperature determination module 174d, an HC supply estimation module 174e, and an HC leakage limit determination module 174f. It should be understood that... Figure 2 Only one embodiment of controller 170 is shown, and any other controller capable of performing the operations described herein can be used.

[0138] Processor 172 may include a microprocessor, a programmable logic controller (PLC) chip, an ASIC chip, or any other suitable processor. Processor 172 communicates with memory 174 and is configured to execute instructions, algorithms, commands, or other programs stored in memory 174.

[0139] Memory 174 includes any of the memory and / or storage components discussed herein. For example, memory 174 may include RAM and / or a cache for processor 172. Memory 174 may also include one or more storage devices (e.g., hard disk drives, flash drives, computer-readable media, etc.) that are local or remote relative to controller 170. Memory 174 is configured to store, for example, lookup tables, algorithms, or instructions for controlling regeneration.

[0140] In one configuration, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f are implemented as a machine-readable medium or a computer-readable medium (e.g., stored in memory 174) executable by a processor (e.g., processor 172). As described herein and among other uses, the machine-readable medium (e.g., memory 174) facilitates certain operations of the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f to achieve data reception and transmission. For example, the machine-readable medium can provide instructions (e.g., commands, etc.) to, for example, acquire data. In this respect, the machine-readable medium may include programmable logic that defines the frequency of data acquisition (or data transmission). Therefore, computer-readable media can include code, which can be written in any programming language, including but not limited to Java and any conventional procedural programming language, such as the "C" programming language or similar programming languages. Computer-readable program code can be executed on one processor or multiple remote processors. In the latter case, remote processors can be interconnected via any type of network (e.g., CAN bus, etc.).

[0141] In another configuration, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC supply estimation module 174e, and the HC leakage limit determination module 174f are implemented as hardware units, such as electronic control units. Therefore, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC supply estimation module 174e, and the HC leakage limit determination module 174f can be implemented as one or more circuit components, including but not limited to processing circuits, network interfaces, peripheral devices, input devices, output devices, sensors, etc.

[0142] In some embodiments, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (ICs), discrete circuits, system-on-a-chip (SOC) circuits, microcontrollers, etc.), telecommunication circuits, hybrid circuits, and any other type of "circuit". In this regard, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f may include any type of components for performing or facilitating the operation described herein. For example, the circuit described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, etc.

[0143] Therefore, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f may also include programmable hardware devices, such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc. In this regard, the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f may include one or more memory devices for storing instructions executable by the processor of the regeneration request determination module 174a, the regeneration trigger control module 174b, the target temperature determination module 174c, the feedback temperature determination module 174d, the HC allocation estimation module 174e, and the HC leakage limit determination module 174f. The one or more memory devices and the processor may have the same definitions as provided below regarding memory 174 and processor 172.

[0144] In the example shown, controller 170 includes processor 172 and memory 174. Processor 172 and memory 174 may be configured to execute or implement the instructions, commands, and / or control processes described herein regarding regeneration request determination module 174a, regeneration trigger control module 174b, target temperature determination module 174c, feedback temperature determination module 174d, HC allocation estimation module 174e, and HC leakage limit determination module 174f. Therefore, the depicted configuration represents the above arrangement, wherein regeneration request determination module 174a, regeneration trigger control module 174b, target temperature determination module 174c, feedback temperature determination module 174d, HC allocation estimation module 174e, and HC leakage limit determination module 174f are implemented as machine-readable or computer-readable media. However, as stated above, this illustration is not intended to be limiting, as this disclosure contemplates other embodiments such as those described above, wherein at least one of the circuits of the regeneration request determination module 174a, regeneration trigger control module 174b, target temperature determination module 174c, feedback temperature determination module 174d, HC supply estimation module 174e, and HC leakage limit determination module 174f, or the regeneration request determination module 174a, regeneration trigger control module 174b, target temperature determination module 174c, feedback temperature determination module 174d, HC supply estimation module 174e, and HC leakage limit determination module 174f, is configured as a hardware unit. All such combinations and variations are intended to fall within the scope of this disclosure.

[0145] Processor 172 may be implemented as one or more general-purpose processors, application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), digital signal processors (DSPs), a set of processing units, or other suitable electronic processing units. In some embodiments, one or more processors may be shared by multiple circuits (e.g., regeneration request determination module 174a, regeneration trigger control module 174b, target temperature determination module 174c, feedback temperature determination module 174d, HC allocation estimation module 174e, and HC leakage limit determination module 174f), and may include or otherwise share the same processor, which, in some exemplary embodiments, may execute instructions stored or otherwise accessed via different regions of memory. Alternatively or additionally, one or more processors may be configured to perform or otherwise perform certain operations independently of one or more coprocessors. In other example embodiments, two or more processors may be interconnected via a bus to enable independent, parallel, pipelined, or multithreaded instruction execution. All these variations are intended to fall within the scope of this disclosure. Memory 174 (e.g., RAM, ROM, flash memory, hard disk storage, etc.) may store data and / or computer code to facilitate the various processes described herein. Memory 174 may be communicatively connected to processor 172 to provide processor 172 with computer code or instructions for performing at least some of the processes described herein. Furthermore, memory 174 may be or include tangible non-transient volatile memory or non-volatile memory. Therefore, memory 174 may include database components, object code components, scripting components, or any other type of information structure for supporting the various activities and information structures described herein.

[0146] Communication interface 176 may include a wireless interface (e.g., jack, antenna, transmitter, receiver, communication interface, wired terminal, etc.) for data communication with various systems, devices, or networks. For example, communication interface 176 may include an Ethernet card and port for sending and receiving data via an Ethernet-based communication network and / or a Wi-Fi communication interface for communicating with the first sensor 103, the second sensor 105a / 105b, the pressure sensor 107a / 107b, the oxidation catalyst outlet temperature sensor 109a / 109b, the reductant introduction assembly 120, the hydrocarbon introduction assembly, or the engine controller 20. Communication interface 176 may be configured to communicate via a local area network or a wide area network (e.g., the Internet, etc.) and may use various communication protocols (e.g., IP, LON, Bluetooth, ZigBee, radio, cellular, near-field communication, etc.).

[0147] The regeneration request determination module 174a is configured to receive post-processing operating parameter signals from sensors (e.g., first sensor 103, second sensors 105a / 105b, pressure sensors 107a / 107b, oxidation catalyst outlet temperature sensors 109a / 109b, or any other sensors) connected to each of the first branch 101a and the second branch 101b, to determine whether either the first branch 101a or the second branch 101b requires regeneration (i.e., whether one of the filters 140a or 140b is blocked, thus creating a need for regeneration of filters 140a and / or 140b, or whether the catalytic conversion efficiency of the SCR catalyst 150a or 150b has dropped below a threshold, thus creating a need for regeneration of the SCR catalyst 150a and / or 150b).

[0148] The regeneration trigger control module 174b is configured to receive engine operating parameter signals from the engine controller 20 and determine whether engine 10 allows regeneration. If regeneration is allowed by engine 10, the controller 170 determines, based on the post-processing operating parameter signals, whether either the first branch 101a or the second branch 101b is prohibited from regeneration, as previously described. If neither branch 101a nor 101b is prohibited from regeneration, the engine controller 20 allows regeneration, and if at least one of branches 101a or 101b requests regeneration, the regeneration trigger control module 174b generates a regeneration signal to initiate regeneration in both branches 101a and 101b, as previously described.

[0149] The target temperature determination module 174c is configured to determine a target temperature and dynamically adjust the target temperature based on the determined target temperature for each of the first branch 101a and the second branch 101b and the regeneration phase of each branch at various time points, as previously described herein.

[0150] As previously described, the feedback temperature determination module 174d is configured to receive a feedback temperature signal from each of the first branch 101a and the second branch 101b, determine the feedback temperature to determine the target temperature, and control regeneration.

[0151] As previously stated, the HC allocation estimation module 174e is configured to determine the estimated HC allocation based on the final target oxidation catalyst outlet temperature of the oxidation catalysts 130a / 130b, the exhaust flow rate of the exhaust gases discharged from the engine 10, the average oxidation catalyst inlet temperature of the oxidation catalysts 130a / 130b, the average thermal efficiency of the filters 140a / 140b, and the actual or feedback temperature.

[0152] The HC leakage limit determination module 174f is configured to determine the HC leakage limit of each of the first branch 101a and the second branch 101b and generate an HC introduction signal based on the HC leakage limit of each of the branches 101a / 101b and the estimated HC supply amount to introduce a certain amount of hydrocarbons into the engine 10 to induce regeneration, as previously described.

[0153] Figure 3 This is a flowchart illustrating a method 200 for initiating regeneration in an aftertreatment system (e.g., aftertreatment system 100) according to an embodiment, the aftertreatment system including a first branch (e.g., first branch 101a) and a second branch (e.g., second branch 101b). Although reference controller 170, engine 10, and aftertreatment system 100 have been described, operation of method 200 can be used with any aftertreatment system operatively coupled to include multiple branches and any controller coupled to any engine.

[0154] Method 200 includes determining, at 202, whether engine 10 is permitted to regenerate based on signals received from engine controller 20 by controller 170. If controller 170 determines that engine 10 is not permitted to regenerate (202: No), method 200 proceeds to operation 204, and controller 170 does not trigger or initiate regeneration. Then, method 200 returns to operation 202.

[0155] If controller 170 determines that engine 10 is allowed to regenerate (202: Yes), then at 206, controller 170 determines, based on the operating parameters of the first branch 101a and the second branch 101b, whether at least one of the first branch 101a or the second branch 101b needs to regenerate and whether regeneration is prohibited in the first branch 101a or the second branch 101b. If controller 170 determines that neither branch 101a nor 101b needs to regenerate, or if at least one of the branches 101a or 101b needs to regenerate, but one of the branches 101a or 101b is prohibited from regeneration (206: No), then method 200 proceeds to operation 204, and controller 170 does not initiate regeneration.

[0156] On the other hand, if at 208, the controller 170 determines that at least one of the branches 101a / 101b needs regeneration, and regeneration is not prohibited in either the first branch 101a or the second branch 101b (206: Yes), then at 208, the controller 170 initiates regeneration in each of the first branch 101a and the second branch 101b by introducing hydrocarbons (e.g., via hydrocarbon introduction assembly 122) into the engine 10 to increase the temperature of the exhaust gases.

[0157] At 208, controller 170 continues to monitor the regeneration phase of each of the first branch 101a and the second branch 101b. At 212, controller 170 determines whether regeneration in each of the first branch 101a and the second branch 101b is complete. If controller 170 determines that regeneration in at least one of the first branch 101a or the second branch 101b is not complete (212: No), method 200 returns to operation 210, and controller 170 continues to monitor the regeneration phase of each branch 101a / 101b. On the other hand, once controller 170 determines that regeneration in each of the first branch 101a and the second branch 101b is complete, controller 170 stops regeneration at 214.

[0158] Figure 4 It is according to the embodiment for use in Figure 3 This is a schematic flowchart of method 300 for determining and setting the target temperature to which branches 101a / 101b are heated. Method 300 begins after controller 170 is activated, triggered, or initiates regeneration. At 302, controller 170 determines whether each of the first branch 101a and the second branch 101b is in a regeneration phase that occurs before a steady-state phase. If controller 170 determines that each branch 101a / 101b is in a regeneration phase that occurs before a lower steady-state phase, i.e., the steady-state phase has not yet been reached (302: Yes), then controller 170 sets the target temperature to the smaller of a first target temperature for the first branch 101a and a second target temperature for the second branch 101b.

[0159] If the controller determines that neither branch 101a / 101b is in a regeneration phase that occurs before the steady-state phase (302: No), then at 306 the controller 170 determines whether one of the first branch 101a or the second branch 101b is in a regeneration phase that occurs before the steady-state phase, and whether the other of the first branch 101a or the second branch 101b is in a regeneration phase that occurs after the steady-state phase. In response to one of the first branch 101a or the second branch 101b being in a regeneration phase that occurs before the steady-state phase and the other of the first branch 101a or the second branch 101b being in a regeneration phase that occurs after the steady-state phase (306: Yes), the method proceeds to operation 308, and the controller 170 raises the target temperature to a regulated target temperature greater than the smaller of a first target temperature of the first branch 101a and a second target temperature of the second branch 101b.

[0160] At 310, controller 170 determines whether the hysteresis branch (i.e., one of the branches in the first branch 101a or the second branch 101b that is in the regeneration phase preceding the steady-state phase) has reached its steady-state phase. If controller 170 determines that the hysteresis branch has not yet reached its steady-state phase (310: No), the method returns to operation 308, and controller 170 continues to raise the target temperature to the regulated target temperature (e.g., continues to raise the regulated target temperature). In response to determining that one of the first branch 101a or the second branch 101b has reached its steady-state phase (310: Yes), at 312, controller 170 maintains the target temperature at the regulated target temperature.

[0161] At 314, controller 170 determines whether the hysteresis branch in branches 101a / 101b has completed its steady-state phase. If controller 170 determines that the hysteresis branch in branches 101a / 101b has not yet completed its steady-state phase (314: No), the method returns to operation 312, and controller 170 continues to maintain or hold the target temperature at the adjusted target temperature. If controller 170 determines that the hysteresis branch in branches 101a / 101b has completed its steady-state phase (314: Yes), then at 316, controller 170 determines whether the actual temperature or feedback temperature of both branches 101a / 101b is greater than the adjusted target temperature. If controller 170 determines that the actual temperature of at least one of the first branch 101a and the second branch 101b is lower than the adjusted target temperature (316: No), then at 318, controller 170 continues to hold the target temperature at the adjusted target temperature.

[0162] In response to determining that the actual temperature of the two branches 101a / 101b is greater than the adjusted target temperature (316: Yes), at 322, the controller 170 sets the target temperature to the smaller of the first target temperature of the first branch 101a and the second target temperature of the second branch 101b.

[0163] If at operation 306 the controller 170 determines that the regeneration stage in both branches 101a / 101b is not lower than the steady-state stage (306: No), then at 320 the controller determines whether the regeneration stage in both branches 101a / 101b is greater than the steady-state stage. If the controller 170 determines that the regeneration stage in both branches is not greater than the steady-state stage (320: No), then method 300 returns to operation 302. On the other hand, in response to the regeneration stage in each of the first branch 101a and the second branch 101b being greater than the steady-state stage (320: Yes), method 300 proceeds to operation 322, and the controller 170 sets the target temperature to the smaller of the first target temperature and the second target temperature.

[0164] Figure 5 This is a schematic flowchart of a method 400 for determining a feedback temperature according to an embodiment, which can be used to control regeneration performed via method 200. Method 400 begins after controller 170 activates, triggers, or initiates regeneration. Method 400 includes determining at 402 whether both first branch 101a and second branch 101b are in a regeneration phase that occurred prior to a target phase. For example, controller 170 may receive a first feedback temperature signal from first branch 101a and a second feedback temperature signal from second branch 101b to determine the first feedback temperature of first branch 101a and the second feedback temperature of second branch 101b, respectively. Controller 170 may determine the regeneration phase of first branch 101a based on the first feedback temperature and determine the regeneration phase of second branch 101b based on the second feedback temperature.

[0165] In response to the controller 170 determining that each of the first branch 101a and the second branch 101b is in a regeneration phase that occurs before the target regeneration phase of each of the first branch 101a and the second branch 101b (402: Yes), at 404, the controller 170 uses the larger of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine 10 to cause the temperature of the exhaust gas to rise to the target temperature.

[0166] If controller 170 determines that at least one of the first branch 101a or the second branch 101b is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase (402: No), then at 406 controller 170 determines whether at least one of the first branch 101a or the second branch 101b remains above the target temperature for more than a first time period. If at 406 controller 170 determines that neither the first feedback temperature nor the second feedback temperature remains above the target temperature during the first time period (406: No), then at 408 controller 170 uses the average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine 10 to raise the temperature of the exhaust gas to the target temperature. On the other hand, in response to controller 170 determining that one of the first feedback temperature or the second feedback temperature remains above the target temperature during the first time period, then at 410 controller 170 uses the weighted average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine 10 to raise the temperature of the exhaust gas to the target temperature. The weighted average may be biased towards the branch with the higher feedback temperature in either the first branch 101a or the second branch 101b. Then, method 400 returns to operation 402.

[0167] Figure 6This is a schematic flowchart of method 500 according to an embodiment, which is used to set a hydrocarbon supply amount to prevent hydrocarbon leakage through each of the first branch 101a and the second branch 101b of the aftertreatment system 100 during regeneration performed by the controller 170 via method 200. Method 500 begins upon regeneration activation and includes determining at 502 whether the emission flow rate of the exhaust gas discharged from the engine 10 is greater than a flow threshold. If the emission flow rate is less than the flow threshold (502: No), then at 504, the controller 170 sets the hydrocarbon introduction to zero, i.e., no hydrocarbons are introduced into the engine 10. Method 500 then returns to operation 502, and the controller 170 continues to monitor the emission flow rate.

[0168] In response to determining that the emission flow rate is greater than a flow threshold (502: Yes), at 506, controller 170 determines the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst 130a / 130b included in each of the first branch 101a and the second branch 101b of the aftertreatment system 100, and determines whether the oxidation catalyst inlet temperature is less than the ignition temperature of the oxidation catalyst 130a / 130b. If controller 170 determines that the oxidation catalyst inlet temperature of at least one of the oxidation catalysts 130a / 130b is lower than its corresponding ignition temperature (506: Yes), at 508, controller 170 sets hydrocarbon introduction to zero, i.e., hydrocarbons are not introduced into the engine 10. Then, method 500 returns to operation 506, and controller 170 continues to monitor the oxidation catalyst inlet temperature of each oxidation catalyst 130a / 130b.

[0169] In response to the oxidation catalyst inlet temperature of each of the first branch 101a and the second branch 101b of the aftertreatment system 100 being greater than their respective ignition temperatures (506: No), at 510, the controller 170 determines whether the estimated hydrocarbon allowance to be introduced into the engine 10, as determined by the controller 170, is less than the first branch hydrocarbon leakage limit of the first branch 101a and the second branch hydrocarbon leakage limit of the second branch 101b. In response to the estimated hydrocarbon allowance being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit (510: Yes), at 512, the controller 170 sets the hydrocarbon allowance to be supplied to the engine 10 to the estimated hydrocarbon allowance.

[0170] On the other hand, if the estimated hydrocarbon supply at 510 is greater than the hydrocarbon leakage limit of both branches 101a / 101b (510: No), then at 514, controller 170 determines whether the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch. In response to the first branch hydrocarbon leakage limit being greater than the second branch hydrocarbon leakage limit (514: Yes), at 516, controller 170 sets the second branch hydrocarbon leakage limit to the hydrocarbon supply amount. On the other hand, in response to the first branch hydrocarbon leakage limit being less than the second branch hydrocarbon leakage limit, at 518, controller 170 sets the first branch hydrocarbon leakage limit to the hydrocarbon supply amount. Then, method 500 returns to operation 506.

[0171] It should be noted that the term "example" used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations and / or illustrations of possible embodiments (and such terms are not intended to mean that such embodiments must be particular or excellent examples).

[0172] As used herein, the term "joint" or similar means the direct or indirect engagement of two components with each other. Such engagement can be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such engagement can be achieved by integrally forming two components or two components and any additional intermediate components into a single whole, or by attaching two components or two components and any additional intermediate components to each other.

[0173] It is important to note that the structures and arrangements of the various exemplary embodiments are merely illustrative. While only a few embodiments are described in detail in this disclosure, those skilled in the art will readily recognize that many modifications (e.g., variations in the size, dimensions, structure, shape and proportion of various elements, values ​​of parameters, mounting arrangements, use of materials, color, orientation, etc.) are possible without substantially departing from the novel teachings and advantages of the subject matter described herein. Furthermore, it should be understood that features from one embodiment disclosed herein can be combined with features from other embodiments disclosed herein, as will be understood by those skilled in the art. Other substitutions, modifications, variations, and omissions may also be made in the design, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of the presented embodiments.

[0174] While this specification contains numerous specific implementation details, these should not be construed as limiting any embodiment or the scope of the claims, but rather as descriptions of features characteristic of particular implementations of specific embodiments. Certain features described in the context of individual implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations. Furthermore, although features may be described above as functioning in certain combinations, or even initially claimed as such, in some cases one or more features from a claimed combination may be removed from that combination, and the claimed combination may refer to a sub-combination or a variation of a sub-combination.

Claims

1. A controller for controlling the regeneration of at least one of a selective catalytic reduction catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of the exhaust gases, the controller being configured to: Determine whether the engine is allowed to regenerate based on the engine's operating parameters; In response to determining that the engine is allowed to regenerate, it is determined, based on the operating parameters of the first branch and the second branch, whether regeneration is required in at least one of the first branch or the second branch, and whether regeneration is prohibited in the first branch or the second branch; In response to determining (i) that regeneration is required in at least one of the first branch or the second branch and (ii) that regeneration is not prohibited in the first branch or the second branch, hydrocarbons are introduced into the engine, thereby raising the temperature of the exhaust gas to a target temperature and causing regeneration in each of the first branch and the second branch; Monitor the regeneration phase of each of the first branch and the second branch; as well as In response to each of the first branch and the second branch being in a regeneration phase corresponding to a steady phase or in a regeneration phase occurring before said steady phase, the target temperature is set to the smaller of a first target temperature of the exhaust gas flowing through the first branch and a second target temperature of the exhaust gas flowing through the second branch.

2. The controller of claim 1 is further configured to abort regeneration in response to determining that the engine is not allowed to regenerate.

3. The controller of claim 1 is further configured to abort regeneration in response to determining that regeneration is prohibited in either the first branch or the second branch.

4. The controller according to claim 1 is further configured to: In response to determining that regeneration is complete on each of the first and second branches based on the monitored regeneration stage, the introduction of hydrocarbons into the engine is stopped.

5. The controller of claim 1 is further configured to, in response to a regeneration phase occurring before the steady-state phase in one of the first branch or the second branch and a regeneration phase occurring after the steady-state phase in the other of the first branch or the second branch, raise the target temperature to an adjusted target temperature greater than the smaller of the first target temperature and the second target temperature.

6. The controller according to claim 5 is further configured to: Determine whether a branch in the first or second branch that is in a regeneration phase preceding the said steady phase has reached the said steady phase; and In response to determining that one of the first or second branches has reached the steady-state phase, the target temperature of the exhaust gas is maintained at the adjusted target temperature until the steady-state phase of one of the first or second branches is completed.

7. The controller of claim 6 is further configured to set the target temperature to the smaller of the first target temperature and the second target temperature in response to a regeneration phase occurring after the steady-state phase in each of the first branch and the second branch, or to a greater than the regulated target temperature in each of the first branch and the second branch.

8. The controller according to claim 1 is further configured to: Receive 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 the first feedback temperature of the first branch and the second feedback temperature of the second branch, respectively; and In response to determining that each of the first branch and the second branch is in a regeneration phase that occurs prior to a target regeneration phase in each of the first branch and the second branch, the greater of the first feedback temperature and the second feedback temperature is used to control the amount of hydrocarbons introduced into the engine so that the temperature of the exhaust gas is raised to the target temperature.

9. The controller of claim 8 is further configured to, in response to determining (i) that at least one of the first branch or the second branch is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase and (ii) that neither of the first feedback temperature or the second feedback temperature remains above the target temperature for a first time period, use the average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine to raise the temperature of the exhaust gas to the target temperature.

10. The controller of claim 8 is further configured to, in response to determining that (i) at least one of the first branch or the second branch is in the target regeneration phase or in a regeneration phase occurring after the target regeneration phase and (ii) one of the first feedback temperature or the second feedback temperature remains above the target temperature for a first time period, use a weighted average of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine to raise the temperature of the exhaust gas to the target temperature.

11. The controller according to any one of claims 1-10, further configured to: Determine the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst included in each of the first and second branches of the aftertreatment system; In response to the oxidation catalyst inlet temperature of each of the first and second branches of the aftertreatment system being greater than the ignition temperature, it is determined whether the estimated hydrocarbon allowance to be introduced into the engine is less than the hydrocarbon leakage limit of the first branch of the first branch and the hydrocarbon leakage limit of the second branch of the second branch. as well as In response to the estimated hydrocarbon supply being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit, the hydrocarbon supply amount to be supplied to the engine is set to the estimated hydrocarbon supply amount.

12. The controller of claim 11 is further configured to: In response to determining that the estimated hydrocarbon supply is greater than each of the hydrocarbon leakage limits of the first branch and the second branch, determine whether the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch; and In response to the fact that the hydrocarbon leakage limit of the first branch is greater than the hydrocarbon leakage limit of the second branch, the hydrocarbon leakage limit of the second branch is set to the hydrocarbon supply amount, or In response to the fact that the hydrocarbon leakage limit of the first branch is less than the hydrocarbon leakage limit of the second branch, the hydrocarbon leakage limit of the first branch is set as the hydrocarbon supply amount.

13. A post-processing system, comprising: A first branch and a second branch, the first branch being connected to the engine and configured to receive a first portion of the exhaust gases produced by the engine, and the second branch being connected to the engine and configured to receive a second portion of the exhaust gases produced by the engine, each of the first branch and the second branch comprising: - Selective catalytic reduction catalyst, - A filter installed upstream of the selective catalytic reduction catalyst, and - An oxidation catalyst positioned upstream of the filter; and The controller according to any one of claims 1-12 is coupled to a sensor included in each of the first branch and the second branch.

14. A method for controlling the regeneration of at least one of a selective catalytic reduction catalyst or filter included in a first branch or a second branch of an aftertreatment system, the first branch being configured to receive a first portion of exhaust gases produced by an engine, and the second branch being configured to receive a second portion of the exhaust gases, the method comprising: The controller of each of the first and second branches connected to the after-processing system determines whether the engine is allowed to regenerate based on engine operating parameters; In response to the controller determining that the engine is allowed to regenerate, the controller determines, based on the operating parameters of the first branch and the second branch, whether regeneration is required in at least one of the first branch or the second branch and whether regeneration is prohibited in the first branch or the second branch; In response to the controller determining (i) that regeneration is required in at least one of the first branch or the second branch and (ii) that regeneration is not prohibited in the first branch or the second branch, the controller causes hydrocarbons 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 branch and the second branch; The controller monitors the regeneration phase of each of the first branch and the second branch; as well as In response to each of the first branch and the second branch being in a regeneration phase corresponding to a steady phase or in a regeneration phase occurring before said steady phase, the controller sets the target temperature to the smaller of a first target temperature of the exhaust gas flowing through the first branch and a second target temperature of the exhaust gas flowing through the second branch.

15. The method of claim 14, further comprising: In response to the controller determining that regeneration is complete in each of the first and second branches based on the monitored regeneration stage, the controller stops introducing hydrocarbons into the engine to stop regeneration in each of the first and second branches.

16. The method of claim 14, further comprising, in response to a regeneration phase occurring before the steady-state phase in one of the first branch or the second branch and a regeneration phase occurring during the steady-state phase in the other of the first branch or the second branch, the controller raises the target temperature to the regulated target temperature.

17. The method of claim 14, further comprising: The controller determines the first feedback temperature of the first branch and the second feedback temperature of the second branch; as well as In response to the controller determining that each of the first branch and the second branch is in a regeneration phase that occurs prior to a target regeneration phase for each of the first branch and the second branch, the controller uses the larger of the first feedback temperature and the second feedback temperature to control the amount of hydrocarbons introduced into the engine so that the temperature of the exhaust gas rises to the target temperature.

18. The method according to any one of claims 14-17, further comprising: The controller determines the oxidation catalyst inlet temperature at the inlet of the oxidation catalyst included in each of the first and second branches of the aftertreatment system; In response to the oxidation catalyst inlet temperature of each of the first and second branches of the aftertreatment system being greater than the ignition temperature, the controller determines whether the estimated hydrocarbon allowance to be introduced into the engine is less than the hydrocarbon leakage limit of the first branch of the first branch and the hydrocarbon leakage limit of the second branch of the second branch. as well as In response to the estimated hydrocarbon supply being less than each of the first branch hydrocarbon leakage limit and the second branch hydrocarbon leakage limit, the hydrocarbon supply amount to be supplied to the engine is set to the estimated hydrocarbon supply amount.

Images