System and method for controlling temperature of aftertreatment system

Abstract

The invention relates to a system and method for controlling the temperature of an aftertreatment system. A temperature control is provided. In one example, a method includes, in response to a determination of a first difference between an SCR inlet temperature at a first SCR intake position and a target SCR inlet temperature, adjusting the first SCR intake position to a second SCR intake position to reduce the first difference. The method includes, in response to determining a second difference between the SCR inlet temperature at the second SCR intake location and the target SCR inlet temperature, adjusting the bypass valve position to reduce the second difference.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the Paris Convention priority benefit of Indian Provisional Application No. 202441023778 filed on March 26, 2024. The entire contents of the above application are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to exhaust devices and systems for use with internal combustion engines. background

[0004] Before fuel injection, the air entering the internal combustion engine can be compressed by a compressor, which compresses the air flowing into the engine cylinders. In some embodiments, the internal combustion engine can be an electronically controlled diesel engine. When the exhaust gas containing NOx leaves the exhaust manifold, the exhaust gas flows into the exhaust system's aftertreatment system, which is used to treat the exhaust gas. Conventional exhaust systems include any one of several different components to reduce the level of certain exhaust emissions present in the exhaust gas. Some exhaust systems for diesel-powered internal combustion engines include a selective catalytic reduction (SCR) system to convert NOx (a certain percentage of NO and NO2) into nitrogen (N2) and water vapor (H2O) in the presence of ammonia (NH3). Over time, deposits can form, thereby inhibiting the performance of the aftertreatment system, making it possible to clean the exhaust system. Therefore, there is a need to increase the exhaust temperature in a low temperature environment to clean (e.g., remove (desorb) adsorbed hydrocarbons, remove "coke", minimize deposits, particulate matter, etc.) the aftertreatment system. Overview

[0005] One implementation relates to a method of controlling an internal combustion engine and an aftertreatment system including a selective catalytic reduction (SCR) system. The method includes, in response to determining a first difference between an SCR inlet temperature at a first SCR intake location and a target SCR inlet temperature, adjusting the first SCR intake location to a second SCR intake location to reduce the first difference. The method also includes, in response to determining a second difference between the SCR inlet temperature at the second SCR intake location and the target SCR inlet temperature, adjusting a bypass valve position to reduce the second difference.

[0006] In some embodiments, the method includes determining whether the intake manifold temperature is above a dew point temperature. The method may include adjusting a bypass valve position within a bypass valve opening limit in response to determining that the intake manifold temperature is below the dew point temperature. In some embodiments, the method includes determining a target deviation between an SCR inlet temperature and a target SCR inlet temperature. The method may include determining that the SCR inlet temperature is at the target SCR inlet temperature in response to determining that a difference between the SCR inlet temperature and the target SCR inlet temperature is within the target deviation.

[0007] In some embodiments, determining the target deviation includes determining that a difference between an SCR inlet temperature and a target SCR inlet temperature is between 10 degrees Celsius and 20 degrees Celsius. In some embodiments, the method includes adjusting a first SCR intake position based on detecting that an ambient temperature of the SCR system is between -30 degrees Celsius and 45 degrees Celsius. In some embodiments, the method includes activating an SCR cleaning mode before comparing the SCR inlet temperature at the first SCR intake position to the target SCR inlet temperature. In some embodiments, adjusting the bypass valve position so that the target SCR inlet temperature is between 380 degrees Celsius and 420 degrees Celsius. In some embodiments, adjusting the first SCR intake position includes adjusting an intake throttle valve to an adjusted intake throttle valve position within an intake throttle valve limit. In some embodiments, adjusting the bypass valve position includes adjusting the bypass valve position within the bypass valve limit.

[0008] One implementation relates to a system for an engine, the system being configured to communicate with a compressor. The system includes a conduit downstream of the compressor, the conduit being configured to deliver airflow to an intake manifold of the engine. The system includes a heat exchanger coupled to the conduit, the heat exchanger including a bypass conduit between an inlet of the heat exchanger and an outlet of the heat exchanger. The system includes a bypass valve coupled to the bypass conduit, the bypass valve being configured to allow adjustment of airflow through the heat exchanger and the bypass conduit. The system includes an intake throttle valve coupled to the conduit downstream of the heat exchanger and to the bypass conduit such that airflow from the bypass conduit is introduced into airflow exiting the outlet of the heat exchanger before entering the intake throttle valve, the intake throttle valve regulating airflow entering the engine. The system includes a selective catalytic reduction (SCR) system configured to receive exhaust gas generated by the engine through an SCR inlet. The system includes a controller. The controller is configured to receive sensor data including an SCR inlet temperature and, in response to the SCR inlet temperature being lower than a target SCR inlet temperature, generate a control signal to reduce airflow through the intake throttle valve, thereby reducing a difference between the SCR inlet temperature and the target SCR inlet temperature. In response to the SCR inlet temperature being higher than the target SCR inlet temperature, the controller generates a control signal to increase airflow through the bypass valve, thereby reducing a difference between the SCR inlet temperature and the target SCR inlet temperature.

[0009] In some embodiments, the sensor data includes an intake manifold temperature, and the controller is further configured to generate a control signal to increase airflow through the bypass valve, thereby increasing the intake manifold temperature, in response to the intake manifold temperature being below a dew point temperature. In some embodiments, the controller is further configured to determine the dew point temperature using ambient temperature and ambient pressure data, wherein the sensor data includes ambient temperature and ambient pressure data from a temperature-based ambient pressure (TBAP) sensor disposed upstream of the compressor.

[0010] In some embodiments, the controller is further configured to control the SCR system based on sensor data, the sensor data including at least one of engine speed data, temperature variation data of airflow entering the SCR system, pressure data of airflow entering the engine, temperature data of airflow entering the engine, pressure data of airflow exiting the compressor, or temperature data of airflow exiting the compressor. In some embodiments, the controller is configured to compare a deviation between the SCR inlet temperature and a target SCR inlet temperature with a target deviation, and generate a control signal to increase or decrease airflow in response to the comparison of the deviation with the target deviation. In some embodiments, the target deviation exceeds 10 degrees Celsius.

[0011] One implementation relates to a controller for an internal combustion engine and an exhaust system including a selective catalytic reduction (SCR) system. The controller includes at least one processor coupled to at least one memory device storing instructions, the instructions being configured to cause the controller to execute the instructions when executed by the at least one processor. The instructions include instructions for receiving sensor data associated with engine operating conditions from one or more sensors, the sensor data including a selective catalytic reduction (SCR) inlet temperature. The instructions include instructions for determining a first deviation based on a difference between the SCR inlet temperature and a target SCR inlet temperature. The instructions include instructions for adjusting an intake throttle valve position based on the first deviation to control airflow through the throttle valve in response to the first deviation exceeding an allowable deviation. The instructions include instructions for determining a second deviation based on the adjusted intake throttle valve position and a difference between the SCR inlet temperature and the target SCR inlet temperature. The instructions include instructions for adjusting a bypass valve position based on the second deviation to control airflow through the bypass valve in response to determining that the second deviation exceeds the allowable deviation.

[0012] In some embodiments, the instructions include instructions for obtaining a target SCR inlet temperature from a lookup table using sensor data associated with engine operating conditions, wherein the target SCR inlet temperature satisfies a passive cleaning criterion for the SCR system. In some embodiments, the instructions include instructions for determining the target SCR inlet temperature based on SCR conversion efficiency to maintain a target temperature zone for normal operation. In some embodiments, the instructions include instructions for detecting an intake manifold temperature below a dew point temperature and, in response to the detection, generating a control signal to adjust a bypass valve position, wherein the amount of adjustment is based on a difference between the intake manifold temperature and the dew point temperature. In some embodiments, the instructions include instructions for detecting a cold start or light load condition and, in response to the detection of the condition, determining a first deviation based on a difference between the SCR inlet temperature and the target SCR inlet temperature.

[0013] One implementation relates to a method of controlling an internal combustion engine and an aftertreatment system including a selective catalytic reduction (SCR) system. The method includes comparing an SCR inlet temperature at an SCR intake position with a target SCR inlet temperature, adjusting the SCR intake position to an adjusted SCR inlet position such that the SCR inlet temperature at the adjusted SCR inlet position is closer to or at the target SCR inlet temperature in response to determining a difference between the SCR inlet temperature at the SCR intake position and the target SCR inlet temperature, comparing the SCR inlet temperature at the adjusted SCR intake position with the target SCR inlet temperature, and adjusting an initial bypass valve position to an adjusted bypass valve position such that the SCR inlet temperature at the adjusted bypass valve position is closer to or at the target SCR inlet temperature in response to determining a difference between the SCR inlet temperature at the adjusted SCR intake position and the target SCR inlet temperature.

[0014] One implementation relates to a system for an engine. The system may be configured to communicate with a compressor. The system includes a conduit downstream of the compressor, the conduit configured to deliver airflow to an intake manifold of the engine. The system includes a heat exchanger coupled to the conduit downstream of the compressor, the heat exchanger including a bypass conduit between an inlet and an outlet of the heat exchanger. The system includes a bypass valve coupled to the bypass conduit, the bypass valve configured to allow adjustment of airflow through the heat exchanger and the bypass conduit. The system includes an intake throttle valve coupled to the conduit downstream of the heat exchanger and to the bypass conduit, such that airflow from the bypass conduit is introduced into airflow exiting the outlet of the heat exchanger before entering the intake throttle valve, the intake throttle valve regulating airflow entering the engine. The system includes a selective catalytic reduction (SCR) system configured to receive sensor data including an SCR inlet temperature, reduce airflow through an intake throttle valve to achieve a first adjusted SCR inlet temperature closer to the target SCR inlet temperature in response to the SCR inlet temperature being lower than a target SCR inlet temperature, and increase airflow through a bypass valve to achieve a second adjusted SCR inlet temperature closer to the target SCR inlet temperature in response to the first adjusted SCR inlet temperature being lower than the target SCR inlet temperature.

[0015] An implementation relates to a controller for an internal combustion engine and an exhaust system including a selective catalytic reduction (SCR) system. The controller includes at least one processor coupled to at least one memory device storing instructions that, when executed by the at least one processor, cause the controller to perform operations. The operations include receiving sensor data associated with engine operating conditions including a selective catalytic reduction (SCR) inlet temperature from one or more sensors, determining a first deviation based on a difference between the SCR inlet temperature and a target SCR inlet temperature, adjusting an intake throttle valve position by an amount based on the first deviation to control airflow through the throttle valve in response to the first deviation exceeding an allowable deviation, determining a second deviation based on the adjusted intake throttle valve position and the difference between the SCR inlet temperature and the target SCR inlet temperature, and adjusting a bypass valve position by an amount based on the second deviation to control airflow through the bypass valve in response to the second deviation exceeding the allowable deviation.

[0016] It should be appreciated that all combinations of the foregoing concepts and the additional concepts discussed in more detail below (assuming such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings. It is understood that these drawings depict only several embodiments in accordance with the present disclosure and are therefore not to be considered limiting of the scope of the present disclosure, which will be described with additional specificity and detail through use of the accompanying drawings.

[0018] Figure 1 is a schematic diagram of an exhaust system according to an embodiment.

[0019] Figure 2 is an illustration of a flow chart of a method for controlling the temperature of an exhaust system according to an example embodiment.

[0020] Throughout the following detailed description, reference is made to the accompanying drawings. In the drawings, similar symbols generally identify similar parts unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other implementations may be employed 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 various aspects of the present disclosure, as generally described herein and illustrated in the drawings, may be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and form a part of this disclosure. Detailed description

[0021] Referring generally to the accompanying drawings, various embodiments disclosed herein generally relate to systems and methods for controlling exhaust gas temperature in an exhaust system. According to the present disclosure, the system includes an exhaust aftertreatment system, which may include a selective catalytic reduction (SCR) system, an intake throttle valve, a bypass valve, and a controller. The controller is communicatively coupled to the exhaust throttle valve, the bypass valve, and the SCR system. The controller is configured to receive an inlet temperature of the selective catalytic reduction system, compare the SCR inlet temperature at an initial intake throttle valve position with a target SCR inlet temperature, and, if a difference exists between the SCR inlet temperature and the target SCR inlet temperature, adjust the initial intake throttle valve position to an adjusted intake throttle valve position in response to determining a difference between the SCR inlet temperature at the SCR inlet position and the target SCR inlet temperature, such that the SCR inlet temperature at the adjusted intake throttle valve position is closer to or at the target SCR inlet temperature. In some embodiments, the controller may adjust the intake throttle valve position to reduce the difference between the SCR inlet temperature and the target SCR inlet temperature. After performing the first comparison, the controller may be configured to compare the SCR inlet temperature at the adjusted SCR intake position with the target SCR inlet temperature and, in response to determining a difference between the SCR inlet temperature at the adjusted SCR intake position and the target SCR inlet temperature, adjust the initial bypass valve position to an adjusted bypass valve position such that the SCR inlet temperature at the adjusted bypass valve position is closer to or at the target SCR inlet temperature.

[0022] Various embodiments of the systems and methods described herein for increasing the exhaust temperature of an exhaust system may provide benefits including, for example, but not limited to, any one or more of the following: (1) reducing inefficiencies of the SCR system by ensuring that the SCR system operates within a temperature range; (2) maintaining the intake manifold temperature above the dew point temperature to avoid condensation; (3) increasing the exhaust temperature under cold operating conditions to assist in the operation of the SCR system; or (4) cleaning the exhaust system, which may include using waste heat to burn off accumulated soot (sometimes referred to as passive regeneration) or increasing fuel usage to provide additional thermal energy to burn off accumulated soot (sometimes referred to as active regeneration).

[0023] In some embodiments, the engine is equipped with an exhaust aftertreatment system that includes a selective catalytic reduction (SCR) configured to reduce NOx emissions output by the engine. The effective operation of the SCR may depend on the temperature within the aftertreatment system. For example, the SCR may provide a conversion efficiency that meets one or more performance standards within a target operating temperature range (e.g., 250°C-400°C) for its normal operating operation as well as cleaning purposes. A controller may be coupled to the aftertreatment system and may be configured to monitor the temperature of the aftertreatment system to ensure that the SCR operates at the target operating temperature range. In some embodiments, the temperature of the SCR system may be below the target operating temperature or operating temperature range. For example, in a low temperature environment, the SCR temperature may not rise to the target operating range due to, for example, lower temperature air delivered to the combustion chamber.

[0024] In response to detecting that the SCR is not operating within a target operating range, the controller can control the operation of one or more components associated with the engine (e.g., an intake throttle valve, a bypass valve, etc.) to cause an increase in the temperature of the air delivered to the SCR and the SCR itself. For example, the controller can use a closed-loop control system to maintain the temperature at the SCR inlet at a predetermined level (e.g., approximately 400°C). More specifically, the controller can adjust the intake throttle valve to control upstream air or control the degree of opening of the bypass valve to control the temperature and humidity level of the SCR relative to the dew point temperature. The controller can measure the temperature of the SCR using an SCR inlet temperature sensor to verify that the exhaust temperature meets the cleaning objectives of the SCR (e.g., by comparing the temperature to a predefined threshold). In some embodiments, the controller adjusts at least one of the intake throttle valve or the bypass valve to a more closed position to reduce the air flow entering the combustion chamber of the engine, that is, to increase the temperature of the exhaust gas flowing into the aftertreatment system to increase the operating temperature of the aftertreatment system.

[0025] Figure 1 A system 100 for an engine is shown according to an example embodiment. In some embodiments, the system 100 can be a vehicle system. The vehicle can be an on-road or off-road vehicle, including but not limited to long-haul trucks, mid-range trucks (e.g., pickup trucks), automobiles, ships, tanks, aircraft, locomotives, mining equipment, and any other type of vehicle that can utilize the system to reduce emissions. The vehicle can include a power system, a fuel system, operator input / output devices, one or more additional vehicle subsystems, and the like. The vehicle can include additional, fewer, or different components or systems such that the principles, methods, systems, devices, processes, etc. of the present disclosure are intended to be applicable to any other vehicle configuration. It should also be understood that the principles of the present disclosure should not be construed as limited to vehicles; rather, the present disclosure is also applicable to stationary equipment such as generators or generator sets.

[0026] Briefly, system 100 may include engine 118, controller 106, heat exchanger 110, second heat exchanger 122, and aftertreatment system 128. In some embodiments, system 100 includes pressure sensor 102 (sometimes referred to as temperature-based ambient pressure (TBAP) sensor 102 or temperature-based absolute pressure (TBAP) sensor 102), compressor 104, air conduit 132, intake throttle valve 112, bypass valve 108, bypass conduit 134, intake manifold temperature sensor 114, intake manifold pressure sensor 116, engine speed sensor 120, engine fan 124, SCR inlet temperature sensor 126, and SCR outlet temperature sensor 130. In some embodiments, bypass valve 108 is an intercooler (CAC) bypass valve.

[0027] In some embodiments, the engine 118 is configured as a compression-ignition internal combustion (IC) engine that utilizes at least one fuel. Within the IC engine 118, air from the atmosphere is combined with the fuel and combusted to power the engine 118. The combustion of the fuel and air in the compression chambers of the engine 118 produces exhaust gas that is operable to be discharged to an exhaust manifold and an aftertreatment system 128. The engine 118 may include an inline engine, a V-engine, a flat engine, a high-horsepower engine, or any other engine including one or more cylinders.

[0028] The air conduit 132 is configured to receive air into the combustion mixture of the system 100. The air conduit 132 may include an air inlet, an air filter, etc. The air received by the air inlet is received by the air filter. The air leaves the air filter after substantially filtering out particulate matter from the air.

[0029] Compressor 104 is configured to compress (e.g., compress oxygen molecules together) the air that flows into one or more cylinders of the internal combustion engine. In some embodiments, compressor 104 may be included in a turbocharger, a supercharger, etc. Compressor 104 may include a propeller (e.g., a compressor impeller) that can be driven or otherwise actuated via a turbine or other driver. When the propeller rotates, air is received or otherwise driven into the propeller to convert air into a high-pressure, low-speed air flow according to a diffusion process. Air (e.g., compressed air) is driven into the engine via an intake manifold. Advantageously, compressed air enables the engine to burn more fuel and generate more power for a given fuel-air ratio.

[0030] In some embodiments, compressed air from compressor 104 is provided to heat exchanger 110. Heat exchanger 110, such as an intercooler or charge air cooler, can be used to cool the compressed air before it enters the cylinders. Heat exchanger 110 can be any type of heat exchanger 110, including but not limited to a parallel flow heat exchanger 110, a counterflow heat exchanger 110, or a crossflow heat exchanger 110. In some embodiments, compressed air from compressor 104 can flow through bypass conduit 134 instead of through heat exchanger 110. Bypass valve 108 can be fluidically coupled to bypass conduit 134 and selectively adjust the flow rate of the portion of compressed air flowing through bypass conduit 134. Bypass valve 108 can adjust the ratio of air flow through the charge air cooler and the bypass line. Bypass valve adjustment can control the temperature of the intake manifold to maintain a temperature above the dew point, which can prevent condensation and resulting corrosion. Intake throttle valve 112 can be configured to control the flow of compressed air into engine 118.

[0031] Various sensors, such as pressure sensors, temperature sensors, speed sensors, etc., may be strategically located throughout the system 100 and may communicate with the controller 106 to monitor the operating conditions of the system 100. In this regard, the controller 106 may receive data from one or more sensors. Furthermore, the controller 106 may determine additional data (e.g., temperature, pressure, speed, etc.) based on the received sensor data. For example, the exhaust gas temperature may be predicted based on the engine inlet temperature and combustion rate.

[0032] like Figure 1 As shown, system 100 includes a TBAP sensor 102, an intake manifold temperature sensor 114, an intake manifold pressure sensor 116, an engine speed sensor 120, an SCR inlet temperature sensor 126, and an SCR outlet temperature sensor 130. TBAP sensor 102 is positioned near air conduit 132 and is configured to measure the temperature of air flowing into air compressor 104. Intake manifold temperature sensor 114 is located downstream of intake throttle valve 112 and is configured to measure the temperature of compressed air flowing into engine 118. Intake manifold pressure sensor 116 is also positioned downstream of intake throttle valve 112 and is configured to measure pressure in the intake manifold. Engine speed sensor 120 may be configured to measure the speed of engine 118. SCR inlet temperature sensor 126 is positioned near the inlet of aftertreatment system 128 and is configured to measure the inlet temperature of the aftertreatment system. SCR inlet temperature sensor 126 is positioned near the outlet of aftertreatment system 128 and is configured to measure the outlet temperature of aftertreatment system 128.

[0033] Exhaust gas from the engine 118 may flow into the second heat exchanger 122 and through the fan 124. The fan 124 rotates to generate a flow of fluid (eg, air, etc.) through the engine 118. This flow of fluid facilitates cooling of the engine 118.

[0034] Exhaust from the engine flows into an aftertreatment system 128. The aftertreatment system 128 is configured to reduce emissions of particulate matter, nitrogen oxides (NOx), hydrocarbons, and other pollutants. In some embodiments, the aftertreatment system 128 includes a diesel particulate filter (DPF), a diesel oxidation catalyst (DOC), a selective catalytic reduction (SCR) system with an SCR catalyst, and an ammonia oxidation (AMOx) catalyst. The aftertreatment system 128 receives the exhaust via at least one of an exhaust manifold, an exhaust throttle valve, a wastegate valve, or a turbine. After treatment, the exhaust flows or otherwise exits the aftertreatment system 128.

[0035] The controller 106 is coupled to the systems / portions of the system 100 and can at least partially control the operation of the system 100 and the associated vehicle. The controller 106 can generate and transmit control signals to generate various adjustments provided herein. For example, the control signals can generate adjustments to the throttle position and bypass valve position mentioned throughout this disclosure. The controller 106 can implement the following: Figure 2 Specifically, the controller 106 may be communicatively coupled to one or more sensors within the system 100 to receive sensor data from the one or more sensors. For example, the controller 106 may receive temperature sensor data indicating temperatures in different parts of the system from the TBAP sensor 102, the intake manifold temperature sensor 114, the SCR inlet temperature sensor 126, and the SCR outlet temperature sensor 130. Based on the temperature sensor data, the controller 106 may determine whether a temperature value associated with the aftertreatment system 128 is above a predetermined level (e.g., 400° C.).

[0036] The controller 106 can control the intake throttle valve 112 or the bypass valve 108 to adjust the temperature of the SCR within the aftertreatment system 128. For example, in response to determining that the temperature value associated with the aftertreatment system 128 is not above a predetermined threshold, the controller 106 can generate and send a control signal to increase the temperature of the SCR. The controller can iteratively adjust the intake throttle valve 112 or the bypass valve 108 to continuously optimize their positions until a target SCR inlet temperature (or deviation within a range) is detected. In some embodiments, closing the intake throttle valve 112 reduces air flow to the combustion chamber of the engine 118 and causes the exhaust gas temperature to subsequently increase. After the first adjustment (e.g., iteratively), the controller 106 can receive an intake manifold temperature measurement from the intake manifold temperature sensor 114 and maintain the intake manifold temperature above the dew point by adjusting the bypass valve 108 to achieve the target intake manifold temperature. For example, the controller can implement a closed control algorithm to manage the position of the intake throttle valve 112 or the bypass valve 108 and other components. Such adjustments can control the SCR temperature, such as may correspond to a range for passive or active regeneration, while maintaining the intake manifold temperature above the dew point to prevent condensation or corrosion.

[0037] In some embodiments, the controller 106 can use a closed-loop algorithm control system to maintain the temperature at the SCR inlet at a predetermined level, such as within a certain range (e.g., approximately 400° C.), by adjusting the opening degree of the intake throttle valve 112 and the bypass valve 108, thereby controlling the temperature of the SCR within the aftertreatment system 128. Such a temperature can be detected by the controller 106 so that the controller 106 can determine that the exhaust gas temperature satisfies the cleaning operation of the SCR. For example, the controller 106 can receive a temperature measured by the SCR inlet temperature sensor 126 and compare the received temperature to a threshold value.

[0038] In some embodiments, the controller 106 (e.g., using a control signal) adjusts the intake throttle valve 112 or the bypass valve 108 to a more closed position, which reduces the air flow into the combustion chamber of the engine 118 to increase the temperature of the exhaust gas flowing into the aftertreatment system 128, thereby increasing the operating temperature of the aftertreatment system 128. In some embodiments, the controller 106 can be a proportional-integral-derivative (PID) control loop for closed-loop algorithmic control to control the temperature within the SCR. In these embodiments, the controller 106 can continuously calculate the difference between the SCR inlet target temperature and the actual SCR inlet temperature. The difference calculated by the controller 106 can be used as feedback into the PID control loop to determine a control signal to reduce the difference between the actual SCR inlet temperature and the target SCR inlet temperature. The control signal can be based on a proportional term, an integral term, and a derivative term.

[0039] The controller 106 may include one or more processors 136 and memory 138. The processor 136 may include a microprocessor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc., or a combination thereof. The memory 138 may include, but is not limited to, an electronic, optical, magnetic, or any other storage device or transmission device capable of providing program instructions to the processor, ASIC, FPGA, etc. The memory 138 may include a memory chip, an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), flash memory, or any other suitable non-transitive memory from which the controller 106 can read instructions. The instructions may include code from any suitable programming language. The memory 138 may include various modules that include instructions configured to be executed or otherwise implemented by the processor 136. Although previously described, Figure 1 An example processor 136 and memory 138 are described for the controller 106, but the subject matter, including the operations described in this specification, may be implemented in other types of digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in a combination of one or more thereof. The processor 136 or memory 138 may be implemented as hardware for performing operations other than control operations, including, but not limited to, any of various data storage, communication, or processing operations.

[0040] Controller 106 may be at least partially implemented by or communicatively coupled to any of various control hardware (not shown) associated with the operation of system 100, including, but not limited to, an engine control unit (ECU) or an engine control module (ECM). In some embodiments, controller 106 may receive or detect one or more signals related to the operation of system 100, such as electrical or electronic signals (sometimes referred to as temperature values, pressure values, or other sensor data, such as ambient pressure data). As described above, controller 106 may cause actuation of system components based on the generation and transmission of control signals. For example, when the temperature of the aftertreatment system is above or below a certain threshold, controller 106 may actuate bypass valve 108 or intake throttle valve 112 by generating and transmitting control signals.

[0041] In some embodiments, the controller 106 includes at least one processor coupled to at least one memory device storing instructions that, when executed by the at least one processor, cause the controller to perform operations. The operations may include receiving sensor data associated with engine operating conditions from one or more sensors, the sensor data including a selective catalytic reduction (SCR) inlet temperature. The operations may include determining a first deviation based on a difference between the SCR inlet temperature and a target SCR inlet temperature. The operations may include adjusting an intake throttle valve position by an amount based on the first deviation to control airflow through the throttle valve in response to the first deviation exceeding an allowable deviation.

[0042] The operation may include determining a second deviation based on the adjusted intake throttle position and a difference between the SCR inlet temperature and the target SCR inlet temperature. The operation may include adjusting the bypass valve position by a certain amount based on the second deviation to control airflow through the bypass valve in response to the second deviation exceeding the allowable deviation. The operation may include determining a target SCR inlet temperature based on the SCR conversion efficiency to maintain a target temperature zone for normal operation. In some embodiments, the operation may include monitoring whether the intake manifold temperature drops below the dew point temperature, and in response to the intake manifold temperature dropping below the dew point temperature, executing control to adjust the bypass valve position by a certain amount based on the difference between the intake manifold temperature and the dew point temperature.

[0043] In some embodiments, the controller 106 is configured to obtain a target SCR inlet temperature from a lookup table, wherein the target SCR inlet temperature is predetermined to meet a passive cleaning criterion of the SCR system. In some embodiments, the first deviation is determined based on a difference between the SCR inlet temperature and the target SCR inlet temperature in response to detecting a cold start or light load operation.

[0044] Although not in Figure 1Although not shown in FIG, system 100 may include sensors such as temperature sensors, pressure sensors, NOx sensors, oxygen sensors, ammonia sensors, or any other sensors. Controller 106 may be communicatively coupled to one or more of these sensors to receive and interpret signals, information, or data from one or more of these sensors. Controller 106 may use information from one or more of these sensors to perform the functions described herein. In some embodiments, the sensor data also includes intake manifold temperature, and the controller is further configured to actuate the bypass valve to increase airflow through the bypass valve to raise the intake manifold temperature in response to the intake manifold temperature falling below the dew point. In some embodiments, the sensor data also includes ambient temperature and pressure from a temperature-based ambient pressure (TBAP) sensor 102 positioned upstream of compressor 104. In some embodiments, the sensor data also includes at least one of engine speed data, temperature change data of the airflow entering the SCR system, pressure data of the airflow entering the engine, temperature data of the airflow entering the engine, pressure data of the airflow exiting the compressor, or temperature data of the airflow exiting the compressor 104.

[0045] Further references Figure 1 , system 100 may include an air conduit 132 downstream of compressor 104, the air conduit 132 configured to deliver airflow to an intake manifold of engine 118. System 100 may include a heat exchanger 110 coupled to air conduit 132 downstream of compressor 104, the heat exchanger 110 including a bypass conduit 134 between an inlet of heat exchanger 110 and an outlet of heat exchanger 110. System 100 includes a bypass valve 108 coupled to bypass conduit 134, the bypass valve 108 configured to allow adjustment of airflow through heat exchanger 110 and bypass conduit 134. System 100 may include an intake throttle valve 112 coupled to the conduit downstream of heat exchanger 110 and coupled to bypass conduit 134, such that airflow from bypass conduit 134 is introduced into airflow exiting the outlet of heat exchanger 110 before entering intake throttle valve 112, which regulates airflow entering engine 118. The system 100 may include a selective catalytic reduction (SCR) system 140 configured to receive exhaust gas generated by the engine via an SCR inlet.

[0046] The controller 106 can receive sensor data including the SCR inlet temperature. In response to the SCR inlet temperature being less than a target SCR inlet temperature, the controller 106 can reduce airflow through the intake throttle valve to achieve a first adjusted SCR inlet temperature closer to the target SCR inlet temperature. In response to the first adjusted SCR inlet temperature being less than the target SCR inlet temperature, the controller 106 can increase airflow through the bypass valve to achieve a second adjusted SCR inlet temperature closer to the target SCR inlet temperature. Thus, the system 100 can increase the operating temperature of the aftertreatment system 128 to meet the target operating temperature. Ensuring that the system 100 operates within the target operating temperature can improve cleaning of the aftertreatment system 128.

[0047] Now refer to Figure 2 , shows a method 200 for controlling an internal combustion engine and an aftertreatment system including a selective catalytic reduction (SCR) system according to an embodiment. For example, the method may be based on Figure 1 The controller coupled with the other components of the depicted system 100 executes instructions to cause the components to perform the method 200 of the present application.

[0048] At operation 202, the controller 106 receives sensor data including the SCR inlet temperature from one or more of the TBAP sensor 102, the intake manifold temperature sensor 114, the intake manifold pressure sensor 116, the engine speed sensor 120, the SCR inlet temperature sensor 126, and the SCR outlet temperature sensor 130. In some embodiments, the sensor data may include data indicating temperatures at various locations within the system 100. In some embodiments, the controller 106 may detect that the ambient temperature of the SCR system is between approximately -30 degrees Celsius and approximately 45 degrees Celsius before comparing the SCR inlet temperature (e.g., at an initial intake throttle position) to a target SCR inlet temperature. For example, the controller may compare the SCR inlet temperature at the intake throttle position to the target SCR inlet temperature based on detecting a temperature between approximately -30 degrees Celsius and approximately 45 degrees Celsius, or perform subsequent operations in response to detecting a temperature between approximately -30 degrees Celsius and approximately 45 degrees Celsius. The ambient temperature may be determined based on, among other things, the sensor data from the TBAP sensor 102.

[0049] At operation 204, the controller 106 may compare the SCR inlet temperature at the SCR intake location with a target SCR inlet temperature. In some embodiments, the SCR inlet temperature is received by the controller 106 from the SCR inlet temperature sensor 126. The target SCR inlet temperature may be predetermined and set to a temperature at which the aftertreatment system 128 converts NOx to nitrogen (N2) and water vapor (H2O) with sufficient efficiency in the presence of ammonia (NH3). In some embodiments, the controller 106 may activate the SCR cleaning mode before comparing the SCR inlet temperature at the intake throttle position with the target SCR inlet temperature. This mode may be referred to as either an active mode or a passive mode, as it may also be based on a pressure differential detected across the soot accumulation, a soot load estimate based on a soot mass model, a timer, or an exhaust gas sensor.

[0050] At operation 206, the controller 106 determines whether there is a difference between the SCR inlet temperature and the target SCR inlet temperature. In some embodiments, the controller 106 may determine a target deviation between the current SCR inlet temperature and the target SCR inlet temperature. The controller 106 may determine whether the difference between the current SCR inlet temperature and the target SCR inlet temperature is within the target deviation. The controller 106 may determine that the current SCR inlet temperature is at the target SCR inlet temperature in response to the difference between the current SCR inlet temperature and the target SCR inlet temperature being within the target deviation. For example, determining the target deviation between the current SCR inlet temperature and the target SCR inlet temperature includes determining that the difference between the current SCR inlet temperature and the target SCR temperature is approximately 10 degrees Celsius to approximately 20 degrees Celsius. If there is no difference between the SCR inlet temperature and the target SCR inlet temperature, the method may proceed to operation 202 to continue receiving and monitoring sensor data. If there is a difference between the SCR inlet temperature and the target SCR inlet temperature (e.g., a difference exceeding the target deviation), the method may proceed to operation 208.

[0051] At operation 208, the controller 106 adjusts the SCR intake position to an adjusted SCR intake position in response to determining a difference between the SCR inlet temperature at the SCR intake position and the target SCR inlet temperature. In some embodiments, the SCR intake position is adjusted so that the SCR inlet temperature at the adjusted SCR intake position is closer to or at the target SCR inlet temperature (e.g., within a deviation threshold). In some embodiments, the controller 106 adjusts the position of the intake throttle valve 112 by sending a control signal to the intake throttle valve 112 to move it toward a more closed position. Adjusting the intake throttle valve 112 to a more closed position can result in a reduction in air flow into the combustion chamber of the engine 118, which increases the temperature of the exhaust gas flowing into the aftertreatment system 128, thereby increasing the operating temperature of the aftertreatment system 128. In some embodiments, the bypass valve position is adjusted so that the target SCR inlet temperature is between approximately 380 degrees Celsius and approximately 420 degrees Celsius. In some embodiments, adjusting the SCR intake position includes adjusting the SCR intake position to an adjusted intake throttle valve position within the intake throttle valve limit.

[0052] At operation 210, the controller 106 compares the SCR inlet temperature at the adjusted intake throttle position to the target SCR inlet temperature to determine if there is a difference between the SCR inlet temperature at the adjusted intake throttle position and the target SCR inlet temperature. If there is no difference between the SCR inlet temperature at the adjusted intake throttle position and the target SCR inlet temperature (or the difference is less than a deviation threshold), the method proceeds to operation 202 to continue receiving and monitoring sensor data. If there is a difference between the SCR inlet temperature at the adjusted intake throttle position and the target SCR inlet temperature, the method proceeds to operation 212.

[0053] At operation 212, the controller 106 adjusts the bypass valve position to an adjusted bypass valve position in response to determining a difference between the SCR inlet temperature at the adjusted intake throttle position and the target SCR inlet temperature. In some embodiments, the controller 106 adjusts the position of the bypass valve 108 by sending a control signal to the bypass valve 108 to move toward a more closed position. Adjusting the bypass valve 108 to a more closed position can reduce air flow into the combustion chamber of the engine 118, which increases the temperature of the exhaust gas flowing into the aftertreatment system 128, thereby increasing the operating temperature of the aftertreatment system 128. In some embodiments, adjusting the bypass valve position includes adjusting the bypass valve position to an adjusted bypass valve position within the bypass valve limits.

[0054] In some embodiments, method 200 may further include determining, by controller 106 , whether the intake manifold temperature is above the dew point temperature. In response to determining that the intake manifold temperature is below the dew point temperature, controller 106 may adjust the bypass valve position within the bypass valve opening limit.

[0055] The schematic flow charts and method diagrams described above are generally described as logical flow charts. Therefore, the depicted order and labeled steps indicate representative embodiments. Other steps, sequences, and methods are contemplated that are equivalent in function, logic, or effect to one or more steps or portions thereof of the method depicted in the schematic diagrams.

[0056] The various concepts described above can be implemented in any of a variety of ways, that is, the concepts described are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0057] The various numerical values ​​provided herein are for reference purposes only. Unless otherwise indicated, all numerals representing the quantity of properties, parameters, conditions, etc. used in this specification and claims should be understood to be modified by the term "approximately" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the specification and the appended claims are approximate values. Any numerical parameter should at least be interpreted based on the number of reported significant figures and by applying ordinary rounding techniques. The term "approximately" when used before a numerical designation, for example, a quantity or a quantitative representation including a range can vary by an approximate value of (+) or (-) 10%, 5% or 1%.

[0058] As will be understood by those skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily identified as fully describing and capable of breaking down the same range into at least equal halves, thirds, fourths, fifths, tenths, etc. As non-limiting examples, each range discussed herein can be easily broken down into a lower third, a middle third, and an upper third, etc. It will also be understood by those skilled in the art that all language, such as "up to," "at least," "greater than," "less than," etc., includes the cited number and refers to a range that can subsequently be broken down into the above-mentioned subranges. Finally, as will be understood by those skilled in the art, a range includes each individual member.

[0059] It should be noted that the term "exemplary" as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representatives, or illustrations of possible embodiments (and such terms are not intended to imply that such embodiments are necessarily particular or excellent examples).

[0060] As used herein, the term "substantially" and similar terms are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the presently disclosed subject matter belongs. Those skilled in the art who review this disclosure should understand that these terms are intended to allow for the description of certain features described and claimed without limiting the scope of such features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the described and claimed subject matter are considered to be within the scope of the present invention as described in the appended claims.

[0061] As used herein, the term "coupled" and its variations refer to two components being directly or indirectly connected to each other. This connection can be static (e.g., permanent or fixed) or movable (e.g., removable or releasable). This connection can be achieved by directly coupling the two components to each other, by coupling the two components to each other using one or more separate intermediate components, or by coupling the two components to each other using an intermediate component that is integrally formed as a single, unitary body with one of the two components. If "coupled" or its variations are modified by additional terms (e.g., directly coupled), the general definition of "coupled" provided above is modified by the plain language meaning of the additional terms (e.g., "directly coupled" means the connection of the two components without any separate intermediate components), resulting in a narrower definition than the general definition of "coupled" provided above. This coupling can be mechanical, electrical, or fluidic. For example, circuit A being communicatively "coupled" to circuit B can mean that circuit A communicates directly with circuit B (i.e., without an intermediary) or indirectly with circuit B (e.g., through one or more intermediaries).

[0062] References herein to element positions (e.g., "top," "bottom," "above," "below") are intended only to describe the orientation of the various elements in the drawings. It should be noted that the orientation of the various elements may differ according to other exemplary embodiments, and such variations are intended to be encompassed by the present disclosure. As used herein, the term "or" is used in its inclusive sense (and not in its exclusive sense), such that when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list.

[0063] Although the drawings and description may show a specific order of method steps, the order of these steps may vary from that depicted and described, unless otherwise specified above. In addition, two or more steps may be performed simultaneously or partially simultaneously, unless otherwise specified above. For example, such variations may depend on the software and hardware systems selected and the designer's choice. All such variations are within the scope of this disclosure. Similarly, software implementations of the described methods can be accomplished using standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.

[0064] It is important to note that the structure and arrangement of the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily recognize that many modifications (e.g., changes in the size, dimensions, structure, shape and proportions of the various elements, parameter values, mounting arrangements, use of materials, orientation, etc.) are possible without materially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the embodiments described herein.

[0065] Although this specification contains specific implementation details, these should not be interpreted as limitations on any embodiment or the scope of the content that may be claimed, but rather as descriptions of features peculiar to specific embodiments of specific embodiments. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Moreover, although the above features may be described as working in certain combinations and even initially claimed as such, one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may involve a deformation of a sub-combination or a sub-combination.

Claims

1. A method of controlling an internal combustion engine and an aftertreatment system including a selective catalytic reduction (SCR) system, the method comprising: In response to determining a first difference between an SCR inlet temperature at a first SCR intake position and a target SCR inlet temperature, adjusting the first SCR intake position to a second SCR intake position to reduce the first difference; and In response to determining a second difference between the SCR inlet temperature at the second SCR intake location and the target SCR inlet temperature, a bypass valve position is adjusted to reduce the second difference.

2. The method according to claim 1, further comprising: Determine if the intake manifold temperature is above the dew point temperature; and In response to determining that the intake manifold temperature is below the dew point temperature, the bypass valve position is adjusted within a bypass valve opening limit.

3. The method according to claim 1, further comprising: determining a target deviation between the SCR inlet temperature and the target SCR inlet temperature; and In response to determining that a difference between the SCR inlet temperature and the target SCR inlet temperature is within the target deviation, it is determined that the SCR inlet temperature is at the target SCR inlet temperature.

4. The method according to claim 3, wherein: Determining the target deviation includes determining that a difference between the SCR inlet temperature and the target SCR inlet temperature is between 10 degrees Celsius and 20 degrees Celsius.

5. The method according to claim 1, further comprising: The first SCR intake position is adjusted based on detecting that the ambient temperature of the SCR system is between -30 degrees Celsius and 45 degrees Celsius.

6. The method according to claim 1, further comprising: An SCR cleaning mode is activated before comparing the SCR inlet temperature at the first SCR intake location to the target SCR inlet temperature.

7. The method according to claim 1, wherein The bypass valve position is adjusted so that the target SCR inlet temperature is between 380 degrees Celsius and 420 degrees Celsius.

8. The method according to claim 1, wherein Adjusting the first SCR intake position includes adjusting an intake throttle valve to an adjusted intake throttle valve position within an intake throttle valve limit.

9. The method according to claim 1, wherein Adjusting the bypass valve position includes adjusting the bypass valve position within bypass valve limits.

10. A system for an engine, the system being configured to communicate with a compressor, the system comprising: a conduit downstream of the compressor, the conduit configured to deliver airflow to an intake manifold of the engine; a heat exchanger coupled to the conduit, the heat exchanger including a bypass conduit between an inlet of the heat exchanger and an outlet of the heat exchanger; a bypass valve coupled to the bypass conduit, the bypass valve configured to allow adjustment of air flow through the heat exchanger and the bypass conduit; an intake throttle valve coupled to a conduit downstream of the heat exchanger and to the bypass conduit so that airflow from the bypass conduit is introduced into airflow exiting the outlet of the heat exchanger before entering the intake throttle valve, the intake throttle valve regulating airflow into the engine; a selective catalytic reduction (SCR) system configured to receive exhaust gas generated by the engine through an SCR inlet; and A controller configured to: Receives sensor data including SCR inlet temperature, generating a control signal to reduce air flow through the intake throttle valve in response to the SCR inlet temperature being lower than a target SCR inlet temperature, thereby reducing a difference between the SCR inlet temperature and the target SCR inlet temperature; and In response to the SCR inlet temperature being greater than the target SCR inlet temperature, a control signal is generated to increase air flow through the bypass valve to reduce a difference between the SCR inlet temperature and the target SCR inlet temperature.

11. The system according to claim 10, wherein: The sensor data also includes intake manifold temperature, and the controller is further configured to: In response to the intake manifold temperature being below a dew point temperature, a control signal is generated to increase airflow through the bypass valve, thereby increasing the intake manifold temperature.

12. The system according to claim 11, wherein The controller is further configured to: The dew point temperature is determined using ambient temperature and ambient pressure data, wherein the sensor data includes ambient temperature and ambient pressure data from a temperature-based ambient pressure (TBAP) sensor disposed upstream of the compressor.

13. The system according to claim 10, wherein: The controller is also configured to control the SCR system based on sensor data, the sensor data including at least one of engine speed data, temperature change data of the air flow entering the SCR system, pressure data of the air flow entering the engine, temperature data of the air flow entering the engine, pressure data of the air flow leaving the compressor, or temperature data of the air flow leaving the compressor.

14. The system according to claim 10, wherein: The controller is configured to: comparing a deviation between the SCR inlet temperature and the target SCR inlet temperature with a target deviation; and The control signal is generated to increase or decrease airflow in response to a comparison of the deviation to the target deviation.

15. The system according to claim 14, wherein: The target deviation exceeded 10 degrees Celsius.

16. A controller for an internal combustion engine and an exhaust system including a selective catalytic reduction (SCR) system, the controller comprising at least one processor coupled to at least one memory device storing instructions, the instructions configured to, when executed by the at least one processor, cause the controller to: receiving sensor data associated with engine operating conditions from one or more sensors, the sensor data including a selective catalytic reduction (SCR) inlet temperature; determining a first deviation based on a difference between the SCR inlet temperature and a target SCR inlet temperature; In response to the first deviation exceeding an allowable deviation, adjusting an intake throttle valve position based on the first deviation to control air flow through the throttle valve; determining a second deviation based on the adjusted intake throttle position and a difference between the SCR inlet temperature and the target SCR inlet temperature; and In response to determining that the second deviation exceeds the allowable deviation, a bypass valve position is adjusted based on the second deviation to control air flow through the bypass valve.

17. The controller according to claim 16, wherein: The instructions include instructions for the following operations: The target SCR inlet temperature is obtained from a lookup table using the sensor data associated with the engine operating conditions, wherein the target SCR inlet temperature meets passive cleaning criteria of the SCR system.

18. The controller according to claim 16, wherein: The instructions include instructions for the following operations: The target SCR inlet temperature is determined based on the SCR conversion efficiency to maintain a target temperature zone for normal operation.

19. The controller according to claim 16, wherein: The instructions include instructions for the following operations: detecting an intake manifold temperature below the dew point; and A control signal is generated in response to the detecting to adjust the bypass valve position, wherein an amount of the adjustment is based on a difference between the intake manifold temperature and the dew point temperature.

20. The controller according to claim 16, wherein The instructions include instructions for the following operations: Detect cold start or light load conditions; and In response to detecting the condition, the first deviation is determined based on a difference between the SCR inlet temperature and a target SCR inlet temperature.

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