Diesel exhaust fluid metering system protection under cold ambient temperature conditions through cylinder deactivation methods

Abstract

Procedure that includes the following: Determine that at least one metering device (78) for a diesel emissions fluid (DEF) of an exhaust aftertreatment system (18) is likely to be frozen based on at least one ambient air temperature and one DEF source temperature, Operating an engine (14) in a cylinder deactivation mode in response to determining that at least one DEF metering unit (78) is likely frozen; and Aborting the cylinder shutdown mode in response to the determination that at least one DEF meter (78) is in a predefined state.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over the preliminary US patent application No. 62 / 818,524, which was filed on March 14, 2019, and is incorporated in full by reference into this document. TECHNICAL AREA

[0002] The present disclosure relates to the operation of an exhaust aftertreatment system in fluid connection with an engine under cold ambient temperature conditions. In particular, the present disclosure relates to systems and methods for controlling the engine to generate exhaust gas in order to prevent overheating of components of the exhaust aftertreatment system during operation under cold ambient temperature conditions.

[0003] EP 2 685 072 A1 discloses a control device for an internal combustion engine. WO 2018 / 152 384 A1 discloses a method and a system for interrupting the ignition of an engine, while DE 11 2014 006 612 T5 discloses a cylinder deactivation for catalyst drying. BACKGROUND

[0004] Vehicles can operate in a wide variety of environmental conditions with a broad range of ambient temperatures. In cold ambient temperatures, some engine subsystems can freeze, especially after the engine has been switched off. For example, in some components, the diesel exhaust fluid (DEF) metering units of an exhaust aftertreatment system, which are in fluid contact with the engine, can freeze. When the DEF metering units are frozen, there is no DEF circulation in the exhaust stream. BRIEF SUMMARY OF THE INVENTION

[0005] One embodiment relates to a method. The method comprises determining that at least one diesel exhaust fluid (DEF) metering device of an exhaust aftertreatment system is frozen, based on at least one ambient air temperature and one DEF source temperature. The exhaust aftertreatment system is in exhaust gas receiving communication with an engine operating under a low-load condition and having a plurality of cylinders. The method comprises operating the engine in a skip-fire ignition mode in response to the determination that the at least one DEF metering device is frozen. The skip-fire ignition mode comprises firing a portion of the plurality of cylinders. This portion of the plurality of cylinders is less than the total number of cylinders in the plurality of cylinders.The procedure involves aborting the ignition cut-off mode in response to the determination that at least one DEF dispenser is likely thawed.

[0006] Another embodiment relates to a device. The device includes a freezing detection circuit and a DEF metering protection circuit. The freezing detection circuit is configured to determine, based on an ambient air temperature and / or a DEF source temperature, that at least one diesel exhaust fluid metering unit of an exhaust aftertreatment system is frozen. The exhaust aftertreatment system is in exhaust gas receiving communication with an engine having a plurality of cylinders and configured to operate according to a low-load condition. The DEF metering protection circuit is configured to operate the engine in an ignition cut-off mode in response to the determination that the at least one DEF metering unit is frozen. The ignition cut-off mode includes firing a portion of the plurality of cylinders.The fraction of the multitude of cylinders is less than the total number of cylinders in the multitude of cylinders. The DEF metering protection circuit is designed to determine that at least one DEF meter is likely thawed and to abort the ignition cut-off mode in response to this determination.

[0007] Another embodiment relates to a system. The system comprises an exhaust aftertreatment system and a control unit. The exhaust aftertreatment system is in exhaust gas receiving communication with an engine having a plurality of cylinders. The engine is configured to operate under low-load conditions. The control unit is configured to determine, based on an ambient air temperature and / or a DEF source temperature, that at least one DEF metering device is frozen. The control unit is configured to operate the engine in an ignition cut-off mode in response to the control unit's determination that the at least one DEF metering device is frozen. The ignition cut-off mode includes firing a portion of the plurality of cylinders. This portion of the plurality of cylinders is less than the total number of cylinders in the plurality of cylinders.The control unit is designed to abort the ignition cut-off mode in response to the determination that at least one DEF doser is likely thawed.

[0008] These and other features, as well as their arrangement and function, will become apparent from the following detailed description in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE FIGURES Fig. Figure 1 is a schematic representation of an engine and an exhaust aftertreatment system with a control unit according to an exemplary embodiment. Fig. Figure 2 is a diagram showing the exhaust gas temperatures of the engine for different engine ignition types according to an exemplary embodiment. Fig. Figure 3 is a schematic representation of a vehicle control unit including the engine and the exhaust aftertreatment system. Fig. 1 according to an exemplary embodiment. Fig. Figure 4 is a flowchart of a method for protecting diesel exhaust fluid (DEF) metering devices under cold engine start-up conditions according to an exemplary embodiment. Fig. Figure 5 is a flowchart of a logical structure for prioritizing the selection of engine ignition conditions according to an exemplary embodiment based on a probability that one of the DEF metering units is frozen and based on a hydrocarbon load of a selective catalytic reduction catalyst (SCR). DETAILED DESCRIPTION

[0009] The following section describes in detail various concepts and implementations of methods, devices, and systems for the dynamic control of an engine according to a DEF metering protection mode, in order to generate exhaust gas with a temperature high enough to thaw frozen diesel exhaust fluid (DEF) metering units and low enough to prevent overheating of the frozen DEF metering units. The various concepts presented here can be implemented in any way, as the described concepts are not limited to a specific implementation method. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0010] Engines can have at least one first cylinder bank with a plurality of first cylinders and a second cylinder bank with a plurality of second cylinders. The engine can fire the first cylinder bank, the second cylinder bank, or both, depending on the required engine output. Each cylinder bank is connected to an exhaust aftertreatment system designed to reduce nitrogen oxides (NOx). x The exhaust gases are reduced to less harmful compounds before leaving the vehicle. The exhaust gas stream may contain a variety of DEF dosing units and a selective catalytic reduction (SCR) catalyst.

[0011] The engine can operate under low-load conditions shortly after starting. In some climates, the vehicle may be parked outdoors in conditions where the ambient air temperature is below freezing for some of the vehicle components. For example, the vehicle may be parked outdoors when the ambient temperature is below freezing for the DEF (Dead Exhaust Fluid). Under such conditions, the DEF metering units, the DEF source, and / or the piping connecting the DEF source to the DEF metering units may freeze. During normal operation of the exhaust aftertreatment system, the DEF flow through the DEF metering units and the DEF airflow around the DEF metering units can cool the DEF metering units through heat transfer (e.g., heat is transferred from a DEF metering unit to the DEF as the DEF passes the DEF metering unit and / or DEF flows around the DEF metering unit in the exhaust stream).However, if the DEF injectors are frozen, no DEF is injected into the exhaust stream, and there is no DEF present in the exhaust stream to dissipate heat from the DEF injectors, which can lead to overheating of the DEF injectors. Accordingly, it is advantageous to identify frozen DEF injectors after starting engines operating in cold ambient conditions and, in response to the identification of frozen DEF injectors, to control the engine to produce exhaust gas at temperatures warm enough to thaw the DEF injectors and cool enough to prevent overheating of the frozen DEF injectors.

[0012] The vehicle may, for example, have an engine control unit (ECU) designed to monitor the engine's fuel demand to achieve the driver's requested engine load and, based on this demand, determine whether different combinations of cylinder banks and / or cylinders should be activated or deactivated. The engine can fire both cylinder banks when a high engine load is requested. Under low-load operating conditions, the engine can operate in an ignition-interrupted (ICI) mode and a single-bank shutdown (SBCO) mode. The ICI mode fires cylinders in both cylinder banks and produces exhaust gas cool enough to defrost the DEF metering units while preventing them from overheating. During the SBCO mode, only one cylinder bank fires.The exhaust gas produced when the engine is operated in SBCO mode is hot enough to regenerate the SKR catalyst, but could cause frozen DEF dosers to overheat.

[0013] The exhaust aftertreatment system also includes filters and catalysts designed to remove dirt and soot from the exhaust gas and reduce NOₓ. xto reduce harmful emissions such as N2 and H2O before the exhaust gas leaves the vehicle. The exhaust aftertreatment system includes, among other things, a selective catalytic reduction (SCR) catalyst. During engine operation, unburned hydrocarbons, dirt, soot, etc., can accumulate on the SCR catalyst, and the SCR catalyst must be regenerated to protect it. The SCR catalyst is regenerated by generating exhaust gas at a very high temperature with the engine, so that the unburned hydrocarbons, dirt, soot, etc., are burned off the SCR catalyst.

[0014] The control unit is designed to determine whether the engine should be operated under low-load conditions at low ambient temperatures to protect frozen DEF injectors and / or the SKR catalyst. The control unit prioritizes, in order of highest to lowest priority, SKR desorption (e.g., SKR catalyst regeneration) in response to the detection of very high levels of bound hydrocarbons, the protection of DEF injectors that are likely to be frozen, SKR desorption in response to the detection of high levels of bound hydrocarbons (e.g., SKR catalyst regeneration), and normal SBCO operation (e.g., without any SKR catalyst regeneration).For example, in response to a determination that the SKR catalyst has a high or very high level of bound hydrocarbons and that at least some DEF metering units are likely frozen, the ECU is configured to run the engine in SBCO mode to regenerate the SKR catalyst. Conversely, in response to a determination that the level of bound hydrocarbons is medium or low and at least one DEF metering unit is likely frozen, the ECU is configured to run the engine in ignition cut-off mode to protect the likely frozen DEF metering units.

[0015] With reference to the figures in general, the various embodiments disclosed herein relate to systems, devices, and methods for controlling the ignition modes of an engine operating at a low load under low-temperature operating conditions, in order to prevent overheating of the DEF metering units of an exhaust aftertreatment system. The systems, devices, and methods are designed to control the engine to produce exhaust gas that is warm enough to thaw the frozen DEF metering unit(s) and cold enough not to overheat them.The systems, devices and methods can also be designed to determine whether the engine's ignition conditions should be controlled to produce exhaust gas at a relatively low temperature to thaw the frozen DEF dosing unit(s), or whether the engine's ignition conditions should be controlled to produce exhaust gas at a relatively high temperature to increase the efficiency of the SKR catalyst, and / or to produce exhaust gas at a temperature high enough to perform SKR catalyst regeneration.

[0016] As in Fig. Figure 1 shows an exemplary embodiment of an engine coupled with two exhaust aftertreatment systems and a control unit. A vehicle has an engine system 10 comprising an internal combustion engine 14 and an exhaust aftertreatment system 18 in exhaust gas receiving connection with the engine 14. According to one embodiment and as shown, the engine 14 is designed as a compression-ignition internal combustion engine that runs on diesel fuel. In various alternative embodiments, however, the engine 14 can also be designed as any other type of engine (e.g., spark-ignition) that uses any type of fuel (e.g., gasoline). In the internal combustion engine 14, air from the atmosphere is combined with fuel and burned to drive the engine. The combustion of fuel and air in the compression chambers of the engine 14 produces exhaust gas, which is directed into an exhaust manifold 68 and into the exhaust aftertreatment system 18.In some embodiments, the engine 14 can be an engine of any size, the cylinders of which are oriented in a V configuration with split exhaust aftertreatment systems. In some embodiments, the engine 14 can be a large-displacement engine with a displacement of at least approximately 30 liters. In some embodiments, the engine 14 can have a displacement of between approximately 30 liters and approximately 120 liters. The term "displacement" as used here generally refers to the volume of gas displaced by all cylinders in the engine 14. In some embodiments, the cylinders can be oriented in a V configuration. In such embodiments, the engine 14 can range from a V8 engine to a V20 engine.

[0017] The engine 14 has at least one first cylinder bank 22 and a second cylinder bank 26. A plurality of combustion cylinders are arranged in the first cylinder bank 22 and the second cylinder bank 26. The engine 14 can be controlled by a control unit 38 to fire different combinations of the cylinder banks 22, 26 and / or the cylinders to achieve the engine load requested by the operator. The control unit 38 can monitor the fuel demand for the engine 14 to achieve the engine load requested by the operator and, based on the fuel demand, determine whether different combinations of the cylinder banks 22, 26 and / or the cylinders should be activated or deactivated. The engine 14 can fire both cylinder banks 22, 26 when a high engine load is required (e.g., under high-load engine operating conditions).The engine 14 can fire a portion of the cylinders within cylinder banks 22 and 26 when a low engine load is required (e.g., under low-load engine operating conditions). In some embodiments, the engine 14 can operate under low-load engine operating conditions according to a skip-firing mode and a single-bank shutdown (SBCO) mode. The term "low-load engine operating condition" refers to an engine operating condition that can be achieved without firing all cylinder banks of the engine 14. The low-load engine operating condition might, for example, consist of the engine 14 operating at idle speed. In another example, the low-load engine operating condition might occur when the vehicle is in use.Such low-load engine operating conditions can include, in each case, a truck traveling downhill, a locomotive traveling at low speed or braking to approach a station, an excavator idling while waiting for a load, a frac or drilling machine idling before driving a pump or drill, a generator idling while waiting to be loaded, etc.

[0018] In ignition-interrupted operating mode, the engine load can be distributed between the first cylinder bank 22 and the second cylinder bank 26 such that a portion of the first cylinder bank 22 and a portion of the second cylinder bank 26 are fired. The portion of the first cylinder bank 22 and the portion of the second cylinder bank 26 that are fired are each smaller than the total number of cylinders in the first cylinder bank 22 and smaller than the total number of cylinders in the second cylinder bank 26. In ignition-interrupted mode, the cylinder firing order skips adjacent cylinders, so that half of the cylinders in the first cylinder bank 22 and the second cylinder bank 26 fire. In a V16 engine, for example, 8 cylinders fire. In some embodiments, the firing cylinders are located at the ends of the first cylinder bank 22 and the second cylinder bank 26.

[0019] In SBCO operating mode, the motor 14 shuts down the first cylinder bank 22 or the second cylinder bank 26 and generates the required load with the remaining operational cylinder bank 22, 26.

[0020] Fig. Figure 2 shows a diagram of the exhaust gas temperature as a function of horsepower at low ambient temperature and under operating conditions with low engine load. Graph 42 shows an engine firing on all cylinders in the first cylinder bank (22) and the second cylinder bank (26). Graph 46 shows an engine operating according to the ignition cut-off mode. Graph 50 shows an engine operating according to the SBCO mode. As in Fig. As shown in Figure 2, the exhaust gas temperature produced by the engine when all cylinders are fired is essentially comparable to the exhaust gas temperature produced by the engine operating in ignition-interrupted mode. The exhaust gas temperature produced by the engine operating in SBCO mode is significantly higher than the exhaust gas produced when the engine is fired on all cylinders or when the engine is fired according to the ignition-interrupted operating mode. Therefore, the command to engine 14 to fire all cylinders or the command to engine 14 to operate according to the ignition-interrupted operating mode can be used to produce exhaust gas at a lower temperature (e.g., compared to SBCO operating conditions) to prevent overheating of components of the exhaust aftertreatment system 18, such as DEF metering units 78.Furthermore, both cylinder banks 22, 26 fire, so that the engine 14 and the exhaust aftertreatment systems 18 heat up essentially uniformly. Under low-load engine operating conditions, the engine 14 operates according to the ignition interruption mode to prevent overheating of the components of the exhaust aftertreatment system 18 in order to reduce fuel consumption (e.g., compared to firing all cylinders).

[0021] Back to Fig. 1: The vehicle has an exhaust aftertreatment system 18, which is in exhaust gas receiving connection with the first cylinder bank 22 and the second cylinder bank 26. For the sake of simplicity, the same numbering is used for the exhaust aftertreatment systems 18 and the components contained therein. Each of the exhaust aftertreatment systems 18 has a diesel particulate filter (DPF) 54, a diesel oxidation catalyst (DOC) 58, a selective catalytic reduction (SCR) system 62 with an SCR catalyst 66, and an ammonia oxidation catalyst (AMOx) 70. The SCR system 62 also has a reducing agent supply system with a diesel exhaust liquid (DEF) source 74, which supplies DEF via a DEF line 82 to a DEF metering device 78.The DEF in the DEF source 74 and / or in the DEF line 82 may freeze under low ambient temperature conditions and prevent the DEF dispensers 78 from dispensing DEF until the DEF in the DEF source 74 and / or the DEF lines 82 has thawed.

[0022] Combustion air enters the engine 14 through an intake manifold 34 and flows to the first and second combustion cylinder banks 22 and 26. In an exhaust flow direction indicated by the direction arrow 84, the exhaust gas flows from the engine 14 into the inlet pipe 86 of the exhaust aftertreatment system 18. From the inlet pipe 86, the exhaust gas flows into the DOK 58 and exits the DOK 58 into a first section of the exhaust pipe 90A. From the first section of the exhaust pipe 90A, the exhaust gas flows into the DPF 54 and exits the DPF 54 into a second section of the exhaust pipe 90B. From the second section of the exhaust pipe 90B, the exhaust gas flows into the SKR catalyst 66 and exits the SKR catalyst 66 into the third section of the exhaust pipe 90C. While the exhaust gas flows through the second section of the exhaust pipe 90B, DEF is added to it at regular intervals by the DEF dosing unit 78.The second section of the exhaust pipe 90B accordingly functions as a decomposition chamber or pipe to facilitate the decomposition of the DEF to ammonia. From the third section of the exhaust pipe 90C, the exhaust gas flows into the AMOx catalyst 70 and exits the AMOx catalyst 70 into the exhaust pipe 94 before being expelled from the exhaust aftertreatment system 18. In the embodiment shown, based on the preceding, the DOK 58 is arranged upstream of the DPF 54 and the SKR catalyst 66, and the SKR catalyst 66 is arranged downstream of the DPF 54 and upstream of the AMOx catalyst 70. However, in alternative embodiments, other arrangements of the components of the exhaust aftertreatment system 18 are also possible (e.g., the AMOx catalyst 70 can be excluded from the exhaust aftertreatment system 18).

[0023] The DOK 58 can have various flow-through designs. Generally, the DOK 58 is designed to oxidize at least some of the particles in the exhaust gas, such as the soluble organic fraction of soot, and to reduce unburned hydrocarbons and CO in the exhaust gas to less harmful compounds. For example, the DOK 58 can be designed to reduce the hydrocarbon and CO concentrations in the exhaust gas to such an extent that the required emission standards for these exhaust gas components are met. An indirect consequence of the DOK 58's oxidation capabilities is its ability to oxidize NO to NO₂. In this way, the amount of NO₂ exiting the DOK 58 is equal to the amount of NO₂ in the exhaust gas produced by the engine 14 plus the amount of NO₂ converted from NO by the DOK 58.

[0024] In addition to treating hydrocarbon and CO concentrations in the exhaust gas, the DOK 58 can also be used for the controlled regeneration of the DPF 54, the SKR catalyst 66, and the AMOx catalyst 70. This is achieved by injecting or dosing unburned hydrocarbons into the exhaust gas upstream of the DOK 58. Upon contact with the DOK 58, the unburned hydrocarbons undergo an exothermic oxidation reaction, leading to an increase in the temperature of the exhaust gas exiting the DOK 58 and subsequently entering the DPF 54, the SKR catalyst 66, and / or the AMOx catalyst 70. The amount of unburned hydrocarbons added to the exhaust gas is selected to achieve the desired temperature increase or the target controlled regeneration temperature.

[0025] The DPF 54 can consist of various flow-through designs and is constructed to reduce the particle concentration, such as soot and ash, in the exhaust gas in order to meet one or more prescribed emission standards. The DPF 54 traps particles and other components and therefore requires regular regeneration to burn off the trapped contaminants. Furthermore, the DPF 54 can be configured to oxidize NO to NO2 independently of the DOK 58.

[0026] The SKR system 62, as described above and in this example configuration, comprises a reducing agent supply system with the DEF source 74, a pump (not shown), and / or a metering device 78. The reducing agent source 74 can be a container or tank containing a reducing agent, such as ammonia (NH3), DEF (e.g., urea), or diesel fuel. The reducing agent source 74 is connected to the pump, which is configured to pump reducing agent from the reducing agent source 74 via a reducing agent supply line to the DEF metering device 78. The DEF metering device 78 is located upstream of the SKR catalyst 66. The control unit 38 is designed to control the timing and quantity of DEF supplied to the exhaust gas. While the disclosure generally refers to the reducing agent DEF, in some embodiments ammonia can be dispensed from the DEF dispensers 78 instead of or in addition to DEF.DEF decomposes to form ammonia. As briefly described above, the ammonia reacts with NO. x in the presence of the SKR catalyst 66, to reduce the NO x to reduce harmful emissions, such as N2 and H2O. The NO x The exhaust gas stream contains NO2 and NO. In general, both NO2 and NO are reduced to N2 and H2O by various chemical reactions driven by the catalytic elements of the SKR catalyst 66 in the presence of NH3.

[0027] The SKR catalyst 66 can be any of the various catalysts known in the art. In some embodiments, for example, the SKR catalyst 66 is a vanadium-based catalyst, and in other embodiments, the SKR catalyst 66 is a zeolite-based catalyst, such as a Cu-zeolite or an Fe-zeolite catalyst. In one representative embodiment, the reducing agent is aqueous urea and the SKR catalyst 66 is a zeolite-based catalyst. In some embodiments, the efficiency of the SKR catalyst 66 is temperature-dependent, meaning that the SKR catalyst 66 produces NO at higher temperatures. x more efficiently reduced to fewer harmful emissions.

[0028] The AMOx catalyst 70 can be one of several flow-through catalysts designed to react with ammonia to primarily produce nitrogen. As briefly described above, the AMOx catalyst 70 is designed to remove ammonia that has passed through or left the SKR catalyst 66 without reacting with NO. x to react in the exhaust gas. In certain cases, the exhaust aftertreatment system 18 can be operated with or without an AMOx catalyst. Although the AMOx catalyst 70 in Fig. 1 and Fig. While the AMOx catalyst 70 is represented as a separate unit from the SKR catalyst 66 in Figure 3, in some implementations it can also be integrated into the SKR catalyst 66; for example, the AMOx catalyst 70 and the SKR catalyst 66 can be housed in the same casing. According to the present disclosure, the SKR catalyst 66 and the AMOx catalyst 70 are arranged in series, with the SKR catalyst 66 positioned upstream of the AMOx catalyst 70.

[0029] Various sensors can be strategically positioned in the engine 14, in the exhaust aftertreatment system 18, and in or near the external environment and communicate with the control unit 38 to monitor the operating conditions of the engine system 10 and the environmental conditions. The sensors can, for example, measure NO. xThe exhaust aftertreatment system 18 comprises sensors 98 and temperature sensors 102, which include an engine intake manifold temperature sensor 106, an engine coolant temperature sensor 110, an ambient temperature sensor 114 (e.g., outdoors), and a temperature sensor 118 for the DEF source 74. In this context, the control unit 38 can receive data from one or more of these sensors. The temperature sensors 102 are connected to the SKR catalyst 66 and can therefore be referred to as SKR temperature sensors 102. The SKR temperature sensors 102 are strategically positioned to detect the temperature of the exhaust gas flowing into and out of the SKR catalyst 66. The engine intake manifold temperature sensor 106 can be positioned on or near the engine intake manifold 34 of the engine system 10 to determine the temperature of the air entering the engine system 10.The engine coolant temperature sensor 110 can be strategically positioned to determine the temperature of the engine coolant. In some embodiments, the ambient temperature sensor 114 can be positioned on or near an exterior surface of the vehicle to determine the temperature of the vehicle's environment. In other embodiments, the ambient temperature sensor 114 can be located at a remote location and be wirelessly connected to the vehicle's control unit 38. In some embodiments, the vehicle does not have an ambient air temperature sensor 114. In such embodiments, the control unit 38 can determine the ambient air temperature from the temperature of the air entering the engine intake manifold, which is detected by sensor 106. The DEF source temperature sensor 118 can be positioned in or near the DEF source 74 to determine the temperature of the DEF within the DEF source 74.

[0030] Although the exhaust aftertreatment system 18 shown comprises a DOK 58, a DPF 54, an SKR catalyst 66, and an AMOx catalyst 70, which are arranged at specific locations relative to each other along the exhaust flow path, the exhaust aftertreatment system 18 can, in other embodiments, as desired, have more than one of the different catalysts arranged at different positions relative to each other along the exhaust flow path. Although the DOK 58 and the AMOx catalyst 70 are non-selective catalysts, in some embodiments the DOK 58 and the AMOx catalyst 70 can also be selective catalysts.

[0031] Fig. Figure 1 is also shown to contain an operator input / output device (I / O) 122. The operator I / O device 122 is communicatively coupled to the control unit 38, so that information can be exchanged between the control unit 38 and the operator I / O device 122, whereby the information relates to one or more components of Fig. 1 or refer to provisions / commands / instructions / etc. (described below) of the control unit 38. The operator I / O device 122 enables an operator of the vehicle (or another passenger) to communicate with the control unit 38 and one or more components of the vehicle and components of Fig. 1. To communicate. The operator I / O device 122 can, for example, include an interactive display, a touchscreen device, one or more buttons and switches, voice command receivers, etc., but is not limited to these. The control unit can provide 38 different pieces of information about the processes described here via the operator I / O device 122.

[0032] The control unit 38 is designed to control the operation of the engine system 10 and the associated subsystems, such as the internal combustion engine 14 and the exhaust aftertreatment system 18. According to one embodiment, the components of the Fig. 1 and Fig. 3. Installed in a vehicle. The vehicle may be a road vehicle or an off-road vehicle, including long-haul trucks, medium-sized trucks (e.g., vans), tanks, aircraft, locomotives, and any other type of vehicle that uses, but is not limited to, an SKR system. In another embodiment, the motor may be housed in a generator. Communication between and among the components may be via any number of wired or wireless connections. A wired connection may, for example, include a serial cable, a fiber optic cable, a CAT5 cable, or any other form of wired connection. By comparison, a wireless connection may include the internet, Wi-Fi, cellular networks, radio, etc. In one embodiment, a Controller Area Network (“CAN”) bus provides the exchange of signals, information, and / or data.The CAN bus contains any number of wired and wireless connections. Since the control unit communicates with the systems and components of 38... Fig. If 1 is connected, the control unit 38 is designed to receive data from one or more of the in Fig. The component shown in section 1 receives the data. The data can be, for example, NO. x -Data (e.g., one from the NO x -Sensor 98 incoming NO x -Quantity and one from the NO x -Sensor 98' outgoing NO xThe data may include quantity), temperature data (e.g., temperatures recorded by the SKR temperature sensor 102, the engine intake manifold temperature sensor 106, the engine coolant temperature sensor 110, the ambient air temperature sensor 114, the DEF source temperature sensor 118), and vehicle operating data (e.g., engine speed, vehicle speed, engine temperature, etc.) received via one or more sensors. As another example, the data may include an input from the operator I / O device 122, such as a requested engine load. The design and function of the control unit 38 are described in relation to Fig. 3 described in more detail.

[0033] With reference to Fig. 3 now shows a schematic diagram of the control unit 38 of the vehicle from Fig. 1 according to an exemplary embodiment. As shown in Fig. As shown in Figure 3, the control unit 38 comprises a processing circuit 126 with a processor 130 and a storage device 134, a freeze determination circuit 138, a DEF dispenser protection circuit 142, a defrost determination circuit 146, an ignition control circuit 150, a prioritization circuit 154, and the communication interface 158. In general, the control unit 38 is configured to determine the probability that at least one of the DEF dispensers is frozen, and in response to determining that at least one of the DEF dispensers is likely to be frozen, it determines a defrost period and operates the engine 14 during the defrost period according to an ignition-off mode.

[0034] In one configuration, the freeze determination circuit 138, the DEF dispenser protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the priority circuit 154 are implemented as machine-readable or computer-readable media that can be executed by a processor, such as the processor 130. As described herein, and among other applications, the machine-readable media facilitate the performance of certain operations to enable the reception and transmission of data. For example, the machine-readable media can provide an instruction (e.g., a command, etc.) to, for instance, acquire data from a specific sensor or a virtual sensor. In this context, the machine-readable media can include programmable logic that determines the frequency of data acquisition (or data transmission).The computer-readable media can contain code written in any programming language, including but not limited to Java or similar languages ​​and any conventional procedural programming language, such as C or similar languages. The computer-readable program code can be executed on a single processor or on multiple remote processors. In the latter case, the remote processors can be interconnected via any type of network (e.g., CAN bus, etc.).

[0035] In another configuration, the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrosting determination circuit 146, the ignition control circuit and the prioritization circuit 154 are implemented as hardware units, e.g. as electronic control units. Thus, the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 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. In some embodiments, the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 can take the form of one or more analog circuits, electronic circuits (e.g.,...)B. integrated circuits (ICs), discrete circuits, system-on-a-chip (SoC) circuits, microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of “circuit.” In this respect, the Freeze Determination Circuit 138, the DEF Dispenser Protection Circuit 142, the Defrost Determination Circuit 146, the Ignition Control Circuit 150, and the Prioritization Circuit 154 may include any type of component to achieve or facilitate the operations described herein. A circuit described herein may, for example, 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.The freezing determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 may also include programmable hardware devices such as field-programmable gate arrays, programmable array logic, programmable logic devices, or the like. The freezing determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 may include one or more memory devices for storing instructions that can be executed by the processor(s) of the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154.The one or more storage devices and the processor(s) can have the same definition as given here with respect to storage device 134 and processor 130. In some hardware unit configurations, the freeze determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 can be geographically distributed across different locations in the vehicle. Alternatively, and as shown, the freeze determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 can be located in or within a single unit / enclosure, represented as control unit 38.

[0036] In the example shown, the control unit 38 has a processing circuit 126 with the processor 130 and the storage device 134. The processing circuit 126 can be constructed or configured to execute or implement the instructions, commands, and / or control processes described herein with respect to the freeze determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154. Thus, the illustrated configuration represents the freeze determination circuit 138, the DEF dosing protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 as machine-readable or computer-readable media.As already mentioned, this description is not intended to be limiting, since the present disclosure also considers other embodiments in which the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrosting determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154, or at least one of the freezing determination circuit 138, the DEF dosing protection circuit 142, the defrosting determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154, is configured as a single hardware unit. All such combinations and variations fall within the scope of the present disclosure.

[0037] The processor 130 can be implemented as one or more general-purpose processors, application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), a digital signal processor (DSP), a group of processing components, or other suitable electronic processing components. In some embodiments, the one or more processors can be shared by several circuits (e.g., the freeze determination circuit 138, the DEF dispenser protection circuit 142, the defrost determination circuit 146, the ignition control circuit 150, and the prioritization circuit 154 can have or otherwise share the same processor, which in some embodiments can execute instructions stored in different memory areas or accessed otherwise).Alternatively or additionally, the one or more processors can be configured to perform certain operations independently of one or more coprocessors or to execute them in some other way. In other exemplary embodiments, two or more processors can be coupled via a bus to enable independent, parallel, pipelined, or multithreaded instruction execution. All such variations fall within the scope of this disclosure. The storage device 134 (e.g., RAM, ROM, flash memory, hard disk storage, etc.) can store data and / or computer code to facilitate the various processes described herein. The storage device 134 can be communicatively connected to the processor 130 to supply the processor 130 with computer code or instructions for executing at least some of the processes described herein.Furthermore, the storage device 134 can be or comprise tangible, non-transient volatile memory or non-volatile memory. Accordingly, the storage device 134 can include database components, object code components, script components, or any other type of information structure to support the various activities and information structures described herein.

[0038] The 158 communication interface can be any combination of wired or wireless interfaces (e.g., sockets, antennas, transmitters, receivers, transceivers, wire connectors, etc.) for data communication with various systems, devices, or networks. For example, the 158 communication interface can include an Ethernet card and a connector for sending and receiving data over an Ethernet-based communication network and / or a WLAN transceiver for communication over a wireless communication network. The 158 communication interface can be configured to communicate over local area networks (LANs) or wide area networks (e.g., the Internet, etc.) and can use a variety of communication protocols (e.g., IP, LON, Bluetooth, ZigBee, radio, cellular communication, near field communication, etc.).

[0039] The communication interface 158 of the control unit 38 facilitates communication between and between the control unit 38 and one or more vehicle components (e.g., components of vehicle subsystems (such as the engine system 10 and the exhaust aftertreatment system 18), the operator I / O device 122, sensors, etc.). Communication between and between the control unit 38 and the vehicle components can be established via any number of wired or wireless connections (e.g., any standard according to IEEE 742, etc.). A wired connection can include, for example, a serial cable, a fiber optic cable, a CAT5 cable, or any other type of wired connection. In contrast, a wireless connection can include the internet, WLAN, cellular networks, Bluetooth, ZigBee, radio, etc. In one embodiment, a CAN bus (Controller Area Network) facilitates the exchange of signals, information, and / or data.The CAN bus can include any number of wired and wireless connections that enable the exchange of signals, information, and / or data. The CAN bus can encompass a local area network (LAN) or a wide area network (WAN), or the connection can be established with an external computer (e.g., via the internet using an internet service provider).

[0040] The freezing detection circuit 138 is designed to be activated in response to the determination that the motor 14 has just been started. The freezing detection circuit 138 receives information from the ambient air temperature sensor 114 indicating the ambient air temperature and from the DEF source temperature sensor 118 indicating the temperature of the DEF stored in the DEF source 74. Based on the information indicating the ambient air temperature and / or the information indicating the temperature of the DEF source 74, the freezing detection circuit 138 determines the probability that at least one of the DEF dispensers 78 is frozen. For example, the freezing detection circuit 138 can be designed to compare the information indicating the ambient air temperature with a predefined ambient air temperature threshold.The freezing detection circuit 138 can compare the information indicating the temperature of the DEF source 74 with a predetermined DEF source temperature threshold. The freezing detection circuit 138 can determine that at least one of the DEF dispensers 78 is likely frozen, in response to determining that the ambient temperature is below the predetermined air temperature threshold and / or in response to determining that the temperature of the DEF source 74 is below the predetermined DEF source temperature threshold. The predetermined air temperature threshold and / or the predetermined DEF source temperature threshold can be a freezing point or a range of freezing points for the DEF. The freezing detection circuit 138 is configured to set a DEF freeze mark or an error code in response to determining that at least one of the DEF dispensers 78 is likely frozen.The freezing determination circuit 138 is designed so that it does not set the DEF freezing mark in response to the determination that the DEF dispensers 78 are not frozen.

[0041] In some embodiments, the freezing detection circuit 138 can be configured to receive information indicating that the DEF in components upstream of the DEF dispensers 78 (e.g., the DEF source 74 and / or the DEF line 82) is frozen. In response to the determination that the DEF in components upstream of the DEF dispensers 78 is frozen, the freezing detection circuit 138 can set the DEF freezing mark.

[0042] In some embodiments, the freezing detection circuit 138 can be configured to determine the probability that at least one of the DEF dispensers is in a non-dispensing state. If the engine has recently been started at low ambient temperatures, the dispensers 78 may be blocked by frozen DEF while in the non-dispensing state. In such an embodiment, the freezing detection circuit 138 is configured to receive information indicating a dispensing state of at least one of the DEF dispensers 78. In some embodiments, the information indicating the dispensing state of at least one of the DEF dispensers 78 may include a pressure at or near at least one of the DEF dispensers 78, a temperature at or near at least one of the DEF dispensers 78, and / or the presence of a blockage at or near at least one of the DEF dispensers 78.The freezing determination circuit 138 can be configured to determine, based on information indicating the dosing state of at least one of the DEF dispensers 78, a probability that at least one of the DEF dispensers 78 is in the non-dosing state. The freezing determination circuit 138 is configured to set a non-dosing marker in response to determining that at least one of the DEF dispensers 78 is likely to be in the non-dosing state. The freezing determination circuit 138 is configured to not set the non-dosing status in response to determining that all of the DEF dispensers 78 are likely to be in the dosing state.

[0043] The DEF metering protection circuit 142 is designed to activate in response to the detection that at least one DEF meter 78 is frozen. For example, the DEF metering protection circuit 142 can be designed to activate in response to the detection that the DEF freeze mark is present. In some embodiments, the DEF metering protection circuit 142 is designed to activate in response to the engine intake manifold temperature 34 falling below a predetermined threshold and / or the engine coolant temperatures falling below a predetermined threshold, in addition to the presence of the DEF freeze mark. The DEF metering protection circuit 142 is designed to receive information indicating the temperature of the DEF stored in the DEF source 74 and / or information indicating the ambient air temperature.The DEF dispenser protection circuit 142 is designed to determine a thawing period based on information indicating the ambient air temperature and / or the temperature of the DEF stored in the DEF source 74. The thawing period may include a time likely required to thaw the at least one DEF dispenser 78, plus an additional buffer period to allow the reducing agent supply system to recover from the frozen DEF dispenser(s) 78. In some embodiments, the additional buffer period may be based on the time required to start the DEF pump(s).In some embodiments, the DEF dispenser protection circuit 142 can determine the defrost period by using the information indicating the ambient air temperature and / or the information indicating the DEF source temperature as inputs to one or more lookup tables. In cases where the defrost time is determined based on different information indicating the ambient air temperature and the information indicating the DEF source temperature, the DEF dispenser protection circuit 142 is configured to use the longer defrost period.

[0044] The DEF metering protection circuit 142 is configured to instruct the ignition control circuit 150 to operate the engine 14 in an ignition-off mode during the thawing period. After the thawing period has elapsed, the DEF metering protection circuit 142 is configured to receive information indicating the state of the DEF meter(s) 78. In the embodiment shown, the state of the DEF meter(s) 78 can be either frozen or thawed. In some embodiments, the information indicating the state of the DEF meter(s) 78 can include the temperature of the DEF source 74, the temperature of the exhaust gas entering the exhaust aftertreatment system 18, and / or the temperature of the DEF at or near one or more DEF meter(s) 78.Based on information indicating the state of the DEF dispenser(s) 78, the DEF dispenser protection circuit 142 can determine that the DEF dispenser(s) 78 are likely thawed. The DEF dispenser protection circuit 142 is designed to terminate the ignition cut-off mode. In response to the determination that the DEF dispenser(s) 78 are likely thawed, the DEF dispenser protection circuit 142 is designed to remove the DEF freeze mark. Removing the DEF freeze mark allows the ignition control circuit 150 to operate the engine 14 in SBCO operating mode under low engine load operating conditions. The DEF dispenser protection circuit 142 is designed to deactivate itself after the DEF freeze mark is removed.In some embodiments, the control unit 38 can set a post-defrost mark in response to the detection that the pump is not started after the removal of the DEF freeze mark.

[0045] In response to the determination that the DEF dispenser(s) 78 are likely not thawed, the DEF dispenser protection circuit 142 is configured to maintain the DEF freeze mark. The DEF dispenser protection circuit 142 is configured to determine a second thawing period based on information indicating the ambient air temperature and / or the temperature of the DEF source 74, as described above. In some embodiments, the DEF dispenser protection circuit 142 is configured to determine the second period at least partially based on information indicating the state of the DEF dispenser(s) 78. The information indicating the state of the DEF dispenser(s) 78 can therefore be used for feedback control of the operations performed by the DEF dispenser protection circuit 142.

[0046] In some embodiments, the DEF dispenser protection circuit 142 can determine a probability that both the DEF dispenser(s) 78 and the DEF stored in the DEF source 74 are likely to have thawed. In such embodiments, the DEF dispenser protection circuit 142 is configured to remove the DEF freeze mark in response to the determination that both the DEF dispenser(s) 78 and the DEF in the DEF source 74 have thawed.

[0047] The ignition control circuit 150 is configured to receive information from an operator I / O device 122, such as an accelerator pedal or a lever, specifying a desired engine load 14. Based on this information and commands and / or feedback from other engine and / or vehicle systems, such as the operator I / O device 122, the ignition control circuit 150 controls the cylinder ignition dynamics of the first cylinder bank 22 and the second cylinder bank 26. In the illustrated embodiment, the ignition control circuit 150 receives commands from the DEF metering protection circuit 142.More precisely, the ignition control circuit 150 is configured to fire the first cylinder bank 22 and the second cylinder bank 26 according to the ignition cut-off mode for the thawing period in response to a command from the DEF metering protection circuit 142. The ignition control circuit 150 is configured to abort the SBCO mode, all load management modes, and all fast idle modes in response to the determination that the DEF freeze mark is present. The ignition control circuit 150 is configured to abort the ignition cut-off mode in response to the determination and / or receipt of information indicating that the DEF metering units 78 are thawed.The ignition control circuit 150 is configured to ignite the first cylinder bank 22 and the second cylinder bank 26 according to the SBCO mode under low engine load operating conditions in response to the determination that the DEF freeze mark is not present. Operating the engine 14 according to the SBCO mode under low engine load operating conditions can reduce the amount of hydrocarbons produced by the engine 14, thereby decreasing the number of SCR catalyst 66 regeneration events that occur when the SCR catalyst 66 has high levels of bound hydrocarbons.

[0048] Fig. Figure 4 shows an exemplary procedure 400 for protecting the DEF dispensers 78 during cold start conditions of the engine 14. In process 404, the freezing detection circuit 138 is activated in response to the determination that the engine 14 has just started. In process 408, the freezing detection circuit 138 receives information indicating the ambient air temperature and / or the temperature of the DEF stored in the DEF source 74. In process 412, the freezing detection circuit 138 determines the probability that at least one of the DEF dispensers 78 is frozen, based on the information indicating the ambient air temperature and / or the temperature of the DEF stored in the DEF source 74. The freezing detection circuit 138 can, for example, compare the information indicating the ambient air temperature with a predefined ambient air temperature threshold.The freeze detection circuit 138 can compare the information indicating the temperature of the DEF source 74 with a predetermined DEF source temperature threshold. In response to determining that at least one of the DEF dispensers 78 is likely frozen, and / or in response to determining that the temperature of the DEF source 74 is below the predetermined DEF source temperature threshold, the freeze detection circuit 138 can determine that the ambient temperature is below the predetermined air temperature threshold. For process 416, the freeze detection circuit 138 sets the DEF freeze mark in response to determining that at least one of the DEF dispensers 78 is likely frozen. For process 420, the freeze detection circuit 138 does not set the DEF freeze mark in response to determining that it is unlikely that one of the DEF dispensers 78 is likely frozen.In process 424, the ignition control circuit 150 controls the motor 14 according to the desired motor load entered by the operator via the operator I / O device 122.

[0049] In process 428, the DEF dispenser protection circuit 142 is activated in response to the detection of the presence of the DEF freeze mark. In process 432, the DEF dispenser protection circuit 142 receives information indicating the ambient air temperature and / or the temperature of the DEF stored in the DEF source 74. In process 436, the DEF dispenser protection circuit 142 determines the defrost period based on the information indicating the ambient air temperature and / or the temperature of the DEF stored in the DEF source 74. In some embodiments, the DEF dispenser protection circuit 142 determines the defrost period by inputting the information indicating the ambient air temperature and / or the information indicating the DEF source temperature into one or more lookup tables.The DEF dispenser protection circuit 142 selects the longer defrost time in cases where the defrost time is determined based on information indicating the ambient air temperature and information indicating the temperature of the DEF source, which are different.

[0050] In process 440, the DEF metering protection circuit 142 is configured to instruct the ignition control circuit to operate the engine 14 in an ignition cut-off mode during the thawing period. During the ignition cut-off mode, the portion of the first cylinder bank 22 and the portion of the second cylinder bank 26 that are fired are each less than the total number of cylinders in the first cylinder bank 22 and less than the total number of cylinders in the second cylinder bank. During the ignition cut-off mode, both the first cylinder bank 22 and the second cylinder bank 26 produce exhaust gas at a lower temperature than a single bank operating in SBCO mode.The temperature of the exhaust gas generated during the ignition interruption mode is hot enough to thaw a frozen DEF doser 78 while simultaneously reducing the likelihood of a frozen DEF doser 78 overheating.

[0051] In process 444, after the thawing period has elapsed, the DEF metering protection circuit 142 is configured to receive information indicating the state of the DEF metering unit(s) 78. In process 448, the DEF metering protection circuit 142 is configured to determine a probability that all DEF metering units 78 have thawed, based on the information indicating the state of the DEF metering unit(s) 78. In some embodiments, the information indicating the state of the DEF metering unit(s) 78 may include the temperature of the DEF source 74, the temperature of the exhaust gas entering the exhaust aftertreatment system 18, and / or the temperature of the DEF at or near one or more DEF metering units 78. In process 452, the DEF dispenser protection circuit 142 removes the DEF freeze mark in response to the determination that the DEF dispenser(s) 78 are likely thawed.In response to the determination that the DEF meter(s) 78 are likely thawed, the DEF meter protection circuit 142 terminates the ignition cut-off mode. At process 456, in response to the removal of the DEF freeze mark, the DEF meter protection circuit 142 is deactivated, and the ignition control circuit 150 controls the first cylinder bank 22 and the second cylinder bank 26 according to the SBCO mode.

[0052] In process 460, the DEF dispenser protection circuit 142 maintains the DEF freeze mark in response to the determination that one or more of the DEF dispensers 78 are likely frozen. The DEF dispenser protection circuit 142 then returns to process 432. In some embodiments, the DEF dispenser protection circuit can also receive information indicating the temperature of one or more DEF dispenser(s) 78 when the DEF dispenser protection circuit 142 repeats process 434.

[0053] The prioritization circuit 154 is designed to be activated under low-load engine operating conditions and low ambient temperature operating conditions. In some embodiments, the low-load engine operating conditions and low temperature operating conditions occur when the engine 14 has just been started. The prioritization circuit 154 is designed to determine whether the engine 14 should be operated to protect the plurality of DEF metering units 78 and / or to protect the SCR catalyst 66. For example, operating the engine 14 in ignition-interrupt mode produces cooler exhaust gas in both the first cylinder bank 22 and the second cylinder bank 26, which is warm enough to thaw a frozen DEF metering unit 78, but cool enough to prevent the frozen DEF metering unit 78 from overheating.However, the SCR catalyst 66 can be more efficient at higher operating temperatures. This means that the cooler exhaust gas produced in ignition-interrupt mode can reduce the efficiency of the SCR catalyst 66 and / or cause DEF buildup on the SCR catalyst 66. Operating the engine 14 according to the SBCO ignition mode generates high-temperature exhaust gas from one of the first cylinder banks 22 and the second cylinder bank 26. The high-temperature exhaust gas generated during SBCO mode can cause the frozen DEF dosing unit(s) 78 to overheat. The SCR catalyst 66 is more efficient at higher exhaust gas temperatures. The SCR catalyst 66 can also undergo regeneration when the engine 14 is operated in a way that generates high-temperature exhaust gas.Therefore, under conditions where the SCR catalyst 66 is heavily loaded with hydrocarbons, operating the engine 14 in SBCO mode can protect the SCR catalyst 66 by burning off at least some of the hydrocarbons on the SCR catalyst 66. The prioritization circuit 154 is designed to prioritize, in order from highest to lowest priority, SCR desorption (e.g., regeneration of the SCR catalyst 66) in response to the determination that very high amounts of bound hydrocarbons are likely present, the protection of the DEF dosing units 78, which are likely frozen (e.g., as indicated by the DEF freeze mark), SCR desorption in response to the determination that high amounts of bound hydrocarbons are likely present (e.g., regeneration of the SCR catalyst 66), and normal SBCO operation (e.g., without any regeneration of the SCR catalyst 66).

[0054] A control logic diagram 500 of the prioritization circuit 154 is generally in Fig. Figure 5 shows that the prioritization circuit 154 is designed to determine whether at least one of the DEF dispensers 78 is likely to be frozen in process 504. For example, the prioritization circuit 154 can be designed to query the defrost determination circuit 146 to determine whether the DEF freeze mark is present or not. If the motor 14 was recently started under cold ambient temperature conditions, the DEF dispenser(s) 78 may be blocked by frozen DEF.The prioritization circuit 154 is designed to determine whether the vehicle will operate at a low operating load under low-temperature operating conditions at process 508 (when at least one DEF dispenser 78 is likely to be frozen) or at process 512 (after it has been determined that the DEF dispensers 78 are likely not frozen), based on information indicating a desired load on the motor 14 from an operator I / O device 122, such as an accelerator pedal or a lever, and information indicating an ambient temperature determined by one or more of the temperature sensors 106, 110, 114, 118.

[0055] The prioritization circuit 154 is designed to determine the hydrocarbon load of the SCR catalyst 66 in processes 516 or 520. For example, the prioritization circuit 154 can determine whether the SCR catalyst 66 has a low to medium hydrocarbon load (e.g., a hydrocarbon load below a predetermined stage 1 threshold) and / or whether the SCR catalyst 66 has a very high hydrocarbon load (e.g., a hydrocarbon load above a predetermined stage 3 threshold) and / or whether the SCR catalyst 66 has a high hydrocarbon load (e.g., at a predetermined stage 2 threshold, which represents a load above the predetermined stage 1 threshold and below the predetermined stage 3 threshold).

[0056] The prioritization circuit 154 is configured to prioritize the selection of engine ignition conditions based on the probability that one of the DEF metering units 78 is frozen and on the basis of a hydrocarbon load of the SCR catalyst 66. The prioritization circuit 154 is configured to operate the engine 14 according to ignition interrupt mode 524 in response to the determination that the DEF freeze mark is present and / or that at least one of the DEF metering units 78 is likely to be frozen and the engine 14 is operating at a low load under low-temperature operating conditions. For example, the prioritization circuit 154 can be configured to operate the engine 14 according to procedure 400.The prioritization circuit 154 is designed to operate the motor 14 according to the ignition interrupt mode 524 in response to the determination that the DEF freeze mark is present, the motor 14 is not operating at a low load under low temperature operating conditions, and the SCR catalyst 66 is operating at a low to medium load.

[0057] The prioritization circuit 154 is designed to prioritize the functionality of the SCR catalyst 66 over preventing overheating of the frozen DEF dispenser(s) 78 (e.g., by selecting operating conditions of the engine 14 that are advantageous for the functionality of the SCR catalyst 66) when the SCR catalyst 66 has a high or very high hydrocarbon load. The prioritization circuit 154 is designed to operate the engine 14 according to the SBCO ignition mode 528 in response to the determination that the DEF freeze mark is present, the engine 14 is not operating at a low load under low-temperature operating conditions, and the SCR catalyst 66 has a high carbon load.The prioritization circuit 154 is designed to shut down the motor 14 in response to the determination that the DEF freeze mark is present, the motor 14 is not operating at a low load under low temperature operating conditions, and the SCR catalyst 66 has a very high hydrocarbon load.

[0058] The prioritization circuit 154 is configured to control the motor 14 based on the load of the SCR catalyst 66 in response to the determination that the DEF freeze mark is not present. The prioritization circuit 154 is configured to operate the motor 14 according to the SBCO ignition mode 528 in response to the determination that the DEF freeze mark is not present and the motor 14 is not operating at a low load under low-temperature operating conditions. The prioritization circuit 154 is configured to operate the motor 14 according to the SBCO ignition mode 528 in response to the determination that the DEF freeze mark is not present, the motor 14 is operating at a low load under low-temperature operating conditions, and the SCR catalyst 66 is experiencing a low or high load.The prioritization circuit 154 is designed to shut down the motor 14 during process 532 in response to the determination that the DEF freeze mark is not present and the motor 14 is operating at low load under low temperature operating conditions and the SCR catalyst 66 has a very high hydrocarbon load.

[0059] No claim element herein shall be construed in accordance with the provisions of 35 USC § 112(f) unless the element is expressly described by the phrase “means for”.

[0060] For the purposes of this disclosure, the term "coupled" means the direct or indirect connection or linking of two elements to one another. These connections may be stationary or movable. For example, a propeller shaft of an engine "coupled" to a gearbox constitutes a movable coupling. Such a connection may be achieved with the two elements or with the two elements and any additional higher-level elements. Thus, for example, the expression "circuit A is communicatively coupled to circuit B" may mean that circuit A communicates directly with circuit B (i.e., without an intermediate switch) or communicates indirectly with circuit B (e.g., via one or more intermediate switches).

[0061] Although in Fig. Since three different circuits with special functionality are shown, it is understood that the control unit 118 can have any number of circuits to perform the functions described herein. For example, the activities and functionalities of circuits 138-154 can be combined in several circuits or as a single circuit. Additional circuits with additional functionality may also be included. Furthermore, the control unit 118 can also control other activities that go beyond the scope of this disclosure.

[0062] As mentioned above and in one configuration, the "circuits" can be implemented in a machine-readable medium for execution by various types of processors, such as the 130 processor from Fig.3. An identified circuit of executable code may, for example, comprise one or more physical or logical blocks of computer instructions, which may be organized, for example, as an object, procedure, or function. However, the executable files of an identified circuit need not be physically located together but may consist of various instructions stored in different locations which, when logically combined, comprise the circuit and fulfill its stated purpose. A circuit of computer-readable program code may consist of a single instruction or of many instructions and may even be distributed across several different code segments, different programs, and multiple storage devices.Similarly, operational data can be identified and represented in circuits, and it can be implemented in any suitable form and organized in any suitable type of data structure. The operational data can be captured as a single data set or distributed across various locations, including different storage devices, and may exist, at least in part, only as electronic signals within a system or network.

[0063] While the term "processor" is briefly defined above, the terms "processor" and "processing circuit" are to be interpreted broadly. As mentioned earlier, the "processor" can be implemented as one or more general-purpose processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), or other suitable electronic data processing components designed to execute instructions provided by memory. The one or more processors can take the form of a single-core processor, a multi-core processor (e.g., a dual-core processor, triple-core processor, quad-core processor, etc.), a microprocessor, and so on. In some embodiments, the one or more processors can be located outside the device; for example, the one or more processors can be a remote processor (e.g., a cloud-based processor).Alternatively or additionally, one or more processors can be located internally and / or locally within the device. In this context, a particular circuit or its components can be located locally (e.g., as part of a local server, a local computer system, etc.) or decentrally (e.g., as part of a remote server such as a cloud-based server). For this purpose, a "circuit" as described herein can have components distributed across one or more locations.

[0064] Although the diagrams shown here depict a specific sequence and composition of the process steps, the order of these steps may differ from the representation. For example, two or more steps may be performed simultaneously or partially simultaneously. Furthermore, some process steps that are performed individually may be combined, steps that are performed as a combined step may be divided into individual steps, the sequence of certain processes may be reversed or otherwise varied, and the type or number of individual processes may be changed or varied. The order or sequence of any element or device may be modified or replaced according to alternative embodiments. All such modifications are to be included within the scope of this disclosure as defined in the appended claims.These variations depend on the chosen machine-readable media and hardware systems, as well as the developer's choice. All such variations fall within the scope of disclosure.

[0065] The foregoing description of the embodiments serves only for illustration and description. It is not intended to be an exhaustive presentation of the disclosure or to limit it to the exact form disclosed, and modifications and variations are possible taking into account the above findings or can be derived from this disclosure. The embodiments have been selected and described to explain the principles of the disclosure and their practical application, so that a person skilled in the art can use the various embodiments with different modifications suitable for the respective use. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the embodiments without exceeding the scope of the present disclosure as expressed in the appended claims.

[0066] Accordingly, the present disclosure may be embodied in other specific forms without deviating from its essence or essential features. The described embodiments are to be regarded in every respect as illustrative only and not limiting. The scope of the disclosure is therefore determined by the appended claims rather than by the preceding description. All modifications that fall within the scope and equivalence of the claims are to be included therein.

Claims

[1] Procedure comprising the following: Determine that at least one metering device (78) for a diesel emissions fluid (DEF) of an exhaust aftertreatment system (18) is likely to be frozen based on at least one ambient air temperature and one DEF source temperature, Operating an engine (14) in a cylinder deactivation mode in response to determining that at least one DEF metering unit (78) is likely frozen; and Aborting the cylinder shutdown mode in response to the determination that at least one DEF meter (78) is in a predefined state. [2] The method of claim 1, further comprising determining a period of time in which the cylinder shutdown mode is likely to defrost the at least one DEF meter (78) based on the ambient air temperature, and terminating the cylinder shutdown mode at one end of the period of time. [3] Method according to claim 1, wherein a plurality of cylinders (22, 26) form a first cylinder row (22) and a second cylinder row (26), and wherein the termination of the cylinder deactivation mode comprises firing one of the first cylinder row (22) and the second cylinder row (26) and not firing the other of the first cylinder row (22) and the second cylinder row (26). [4] Method according to claim 1, wherein the cylinder deactivation mode further comprises controlling the engine (14) to reduce the temperature of an exhaust gas so that the exhaust gas can defrost the at least one DEF metering unit (78) without causing the at least one DEF metering unit (78) to overheat. [5] The method of claim 1, further comprising: Determining a hydrocarbon load of a selective catalytic reduction (SCR) catalyst (66) of the exhaust aftertreatment system (18); Comparing the hydrocarbon load of the SKR catalyst (66) with a predefined threshold value indicating a high hydrocarbon load of the SKR catalyst (66); and In response to the determination that the hydrocarbon load of the SKR catalyst (66) is at or above the previously defined threshold, the cylinder deactivation mode is aborted. [6] Method according to claim 5, wherein terminating the cylinder deactivation mode includes switching off the engine (14). [7] The method of claim 1, further comprising: Determining a hydrocarbon load of a selective catalytic reduction (SCR) catalyst (66) of the exhaust aftertreatment system (18); Comparing the hydrocarbon load of the SKR catalyst (66) with a predefined threshold value indicating a low to medium hydrocarbon load of the SKR catalyst (66); and in response to the determination that the hydrocarbon load of the SKR catalyst is at or above the previously defined threshold, operating the engine (14) in cylinder deactivation mode in response to the determination that at least one DEF metering unit (78) is frozen. [8] System comprising the following: a control unit (38) comprising a processing circuit (126) which includes a storage device (134), wherein the storage device (134) is connected to a processor, wherein the control unit (38) is constructed as follows: to determine, on the basis of at least one ambient air temperature and one DEF source temperature, that at least one diesel exhaust fluid (DEF) metering device (78) of an exhaust aftertreatment system (18) is likely to be frozen, to operate an engine (14) in a cylinder deactivation mode in response to the determination that the at least one DEF metering unit is likely frozen, wherein a portion of a plurality of cylinders (22, 26) of the engine (14) are fired, wherein the portion of the plurality of cylinders (22, 26) is less than the total number of cylinders of the plurality of cylinders; and to abort the cylinder shutdown mode in response to the determination that at least one DEF metering unit (78) is in a predefined state. [9] System according to claim 8, wherein the previously defined state is a thawed or likely thawed state, and wherein the control unit (38) is further configured to determine a period of time in which the cylinder deactivation mode is likely to thaw the at least one DEF metering unit (78) based on the ambient air temperature, and is configured to terminate the cylinder deactivation mode at one end of the period of time. [10] System according to claim 8, wherein the plurality of cylinders forms a first cylinder row (22) and a second cylinder row (26), and wherein the termination of the cylinder deactivation mode comprises firing the first cylinder row (22) and the second cylinder row (26) and not firing the other of the first cylinder row (22) and the second cylinder row (26). [11] System according to claim 8, wherein the cylinder deactivation mode lowers the temperature of the exhaust gas so that the exhaust gas can defrost the at least one DEF metering unit (78) without causing the at least one DEF metering unit (78) to overheat. [12] System according to claim 8, wherein the control unit is further structured as follows: to determine a hydrocarbon load of a selective catalytic reduction (SCR) catalyst (66) of the exhaust aftertreatment system; to compare the hydrocarbon load of the SKR catalyst (66) with a predefined threshold value that indicates a high hydrocarbon load of the SKR catalyst (66); and in response to the determination that the hydrocarbon load of the SKR catalyst (66) is at or above the previously defined threshold, to abort the cylinder deactivation mode. [13] System according to claim 12, wherein canceling the cylinder deactivation mode includes switching off the engine (14). [14] System according to claim 8, wherein the previously defined state is a thawed or likely thawed state. [15] System comprising the following: an exhaust aftertreatment system (18) comprising at least one diesel exhaust fluid (DEF) dosing unit (78); and a control unit (38) that is coupled to the exhaust aftertreatment system (18), wherein the control unit (38) is constructed as follows: to determine, on the basis of at least one ambient air temperature and one DEF source temperature, that the at least one diesel exhaust fluid (DEF) metering device (78) is likely to be frozen; to operate an engine (14) in a cylinder deactivation mode in response to the determination that the at least one DEF metering unit (78) is likely frozen, wherein a portion of a plurality of cylinders (22, 26) of the engine (14) are fired, wherein the portion of the plurality of cylinders (22, 26) is less than the total number of cylinders of the plurality of cylinders; and to abort the cylinder shutdown mode in response to the determination that at least one DEF meter (78) is in a predefined state. [16] System according to claim 15, wherein the control unit is constructed as follows: to determine a period of time based on the ambient air temperature during which the cylinder deactivation mode is likely to defrost the at least one DEF metering unit (78); and to cancel the cylinder deactivation mode at one end of the period. [17] System according to claim 15, wherein the plurality of cylinders forms a first cylinder row (22) and a second cylinder row (26), and wherein the termination of the cylinder deactivation mode comprises firing the first cylinder row (22) and the second cylinder row (26) and not firing the other of the first cylinder row (22) and the second cylinder row (26). [18] System according to claim 15, wherein the cylinder deactivation mode lowers the temperature of the exhaust gas so that the exhaust gas can defrost the at least one DEF metering unit (78). [19] System according to claim 15, wherein the control unit is constructed as follows: to determine a hydrocarbon load of a selective catalytic reduction (SCR) catalyst (66) of the exhaust aftertreatment system (18); to compare the hydrocarbon load of the SKR catalyst (66) with a predefined threshold value that indicates a high hydrocarbon load of the SKR catalyst (66); and in response to the determination that the hydrocarbon load of the SKR catalyst (66) is at or above the previously defined threshold, to abort the cylinder deactivation mode. [20] System according to claim 15, wherein the previously defined state is a thawed or likely thawed state

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