Using back pressure to diagnose engine health and fuel consumption

Abstract

A post-processing system includes a particulate filter configured to receive exhaust gas from an engine and a controller that measures an actual pressure drop across the particulate filter, determines an expected total ash accumulation rate in the particulate filter based on a current duty cycle of the engine, determines an expected pressure drop across the particulate filter based on the expected total ash accumulation rate, compares the expected pressure drop to the actual pressure drop, and determines whether a fuel consumption rate in the engine is abnormal based on the comparison.

Description

Technical Field

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

[0002] An exhaust aftertreatment system is used to treat exhaust gas produced by an internal combustion engine. An exhaust aftertreatment system may include a selective catalytic reduction (SCR) system, which is formulated to reduce nitrogen oxides in the exhaust gas in the presence of a catalyst and a reducing agent. The exhaust aftertreatment system may also include one or more filters to remove debris and other particles from the exhaust gas. By treating exhaust gas using an exhaust aftertreatment system, the level of harmful emissions that would otherwise be released into the atmosphere is reduced. Summary of the Invention

[0003] This disclosure relates to a mechanism for determining an abnormal oil consumption rate in an engine associated with an aftertreatment system. An abnormal fuel consumption rate may indicate wear on engine components. Therefore, by identifying an abnormal fuel consumption rate, wear on engine components can be identified in a timely manner. In some embodiments, an increased fuel consumption rate in the engine may correspond to excessive accumulation of ash and / or soot in the particulate filter of the aftertreatment system. As ash and / or soot accumulate on the particulate filter, the pressure drop across the particulate filter increases. Therefore, the pressure drop signal across the particulate filter can be used to identify an abnormal fuel consumption rate in the engine.

[0004] According to one embodiment of this disclosure, an aftertreatment system is disclosed. The aftertreatment system includes a particulate filter and a controller. The particulate filter is configured to receive exhaust gas from an engine. The controller executes computer-readable instructions stored in a memory to: determine an actual pressure drop across the particulate filter based on pressure measurements across the particulate filter; determine a expected total ash accumulation rate in the particulate filter based on the current duty cycle of the engine; determine an expected pressure drop across the particulate filter based on the expected total ash accumulation rate; compare the expected pressure drop with the actual pressure drop; and determine, based on the comparison, whether the fuel consumption rate in the engine is abnormal.

[0005] According to another embodiment of this disclosure, a method is disclosed. The method includes: a controller of an aftertreatment system determining an actual pressure drop across a particulate filter based on pressure measurements across the particulate filter configured to receive exhaust gas from an engine; the controller determining a expected total ash accumulation rate in the particulate filter based on the current duty cycle of the engine; the controller determining an expected pressure drop across the particulate filter based on the expected total ash accumulation rate; the controller comparing the expected pressure drop with the actual pressure drop; and the controller determining, based on the comparison, whether the fuel consumption rate in the engine is abnormal.

[0006] According to another embodiment of this disclosure, a non-transitory computer-readable medium having computer-readable instructions stored thereon is disclosed. When executed by a controller of an aftertreatment system, the computer-readable instructions cause the controller to perform a process comprising: determining an actual pressure drop across a particulate filter configured to receive exhaust gas from an engine based on pressure measurements across the particulate filter; determining an expected total ash accumulation rate in the particulate filter based on the current duty cycle of the engine; determining an expected pressure drop across the particulate filter based on the expected total ash accumulation rate; comparing the expected pressure drop with the actual pressure drop; and determining, based on the comparison, whether the fuel consumption rate in the engine is abnormal.

[0007] It should be understood that all combinations of the foregoing concepts and the additional concepts discussed in more detail below (provided that these concepts are not contradictory) are contemplated as part of the subject matter disclosed herein. In particular, all combinations of the claimed subjects appearing at the end of this disclosure are contemplated as part of the subject matter disclosed herein. Attached Figure Description

[0008] The foregoing and other features of this disclosure will become more apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. It is to be understood that these drawings depict only a few embodiments according to this disclosure and are therefore not intended to limit the scope of the disclosure, which will be described with additional specificity and detail using the drawings.

[0009] Figure 1 This is an example block diagram of a post-processing system according to some embodiments of the present disclosure.

[0010] Figure 2 This is an overview of some embodiments of the present disclosure for detecting and... Figure 1 An example flowchart of the operation of an engine associated with an increased or abnormal fuel consumption rate in the aftertreatment system.

[0011] Figure 3 This is an overview of some embodiments of the present disclosure for creating [something] for use in [something]. Figure 2 Example flowchart of the operation of the second calibration table used in the process.

[0012] Figure 4 This is an overview of some embodiments of the present disclosure for use based on Figure 3 The second calibration table determines the supply in Figure 2 Example flowchart of the operation using the expected total ash accumulation rate during the process.

[0013] Figure 5A This is an example table showing the relationship between duty cycle and fuel consumption rate according to some embodiments of this disclosure.

[0014] Figure 5B This is an example table showing the relationship between duty cycle and ash accumulation rate according to some embodiments of this disclosure.

[0015] Reference is made to the accompanying drawings throughout the detailed description below. In the drawings, similar symbols generally identify similar parts unless the context otherwise requires. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that aspects of this disclosure, as generally described herein and shown in the accompanying drawings, can be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and form part of this disclosure. Detailed Implementation

[0016] This application relates to an aftertreatment system designed for treating exhaust gas emitted from an engine. The aftertreatment system can remove various types of unwanted components from the exhaust gas before releasing the treated exhaust gas into the atmosphere. Among other components, the aftertreatment system includes a particulate filter configured to remove soot, ash, debris, and other particulate matter from the exhaust gas entering the aftertreatment system. Fuel consumption in the engine is a contributing factor to ash accumulation in the particulate filter. Over time, ash generated by fuel consumption accumulates in the particulate filter and combines with soot, causing limitations (e.g., wear) on engine components. As ash and / or soot accumulate in the particulate filter, the back pressure or pressure drop across the particulate filter increases. This disclosure utilizes the pressure drop signal across the particulate filter to predict the ash and / or soot load response (e.g., the ash and / or soot accumulation rate) and determine when engine components are likely to wear out, or when operation may be abnormal, and when the particulate filter may require regeneration or replacement.

[0017] Specifically, this disclosure provides a mechanism in which a controller can run diagnostics to compare a pressure drop characteristic that changes over time with an adjusted calibration table to determine when the rate of ash and / or soot accumulation is excessive. This determination can be used to flag potential engine problems causing increased fuel consumption before a full overhaul of the particulate filter may be necessary. Specifically, as fuel consumption increases, ash accumulation in the particulate filter also increases. Therefore, an increased fuel consumption rate can indicate increased ash and / or soot accumulation in the particulate filter. Thus, this disclosure provides a mechanism for detecting an increased or abnormal fuel consumption rate to indicate increased ash and / or soot accumulation in the particulate filter.

[0018] In some embodiments, operation of a normal (standard / healthy) engine can be used to create a pressure drop calibration table with soot and / or ash content to estimate the total load of soot and / or ash in the particulate filter as it changes over time. Fuel consumption during the average duty cycle can be measured as a standard reference in a normal (standard / healthy) engine. The calibration table can be combined with an estimate of the fuel consumption rate of a healthy engine during the standard duty cycle to determine whether the particulate filter has accumulated excessive ash and / or soot.

[0019] Now for reference Figure 1 This diagram illustrates an example block diagram of an aftertreatment system 100 according to some embodiments of the present disclosure. The aftertreatment system 100 is configured to receive exhaust gas from an engine 105. The engine 105 may be a compression ignition internal combustion engine (such as a diesel engine), a spark ignition internal combustion engine (such as a gasoline engine), or any other type of engine (such as a natural gas engine, a dual-fuel engine, a biodiesel engine, an E-85 engine, etc.). The engine 105 emits exhaust gas resulting from the combustion of fuel with air in the atmosphere. The exhaust gas is discharged from the engine 105 into a housing 115 via an inlet duct 110.

[0020] The housing 115 defines an internal volume within which one or more components for handling exhaust gases are disposed. To withstand operating conditions, the housing 115 may be formed of a rigid, heat-resistant, and corrosion-resistant material, such as stainless steel, iron, aluminum, metal, ceramic, or any other suitable material. Although in Figure 1The housing 115 has been shown to have a specific shape and size, but the housing can have any suitable cross-section (e.g., circular, square, rectangular, oval, elliptical, polygonal, etc.) and any suitable size. The housing 115 can house an oxidation catalyst 120 for oxidizing nitrogen monoxide and certain types of particulate matter in the exhaust gas and decomposing unburned hydrocarbons in the exhaust gas. In some embodiments, the oxidation catalyst 120 can be a diesel oxidation catalyst (“DOC”) or other type of oxidation catalyst suitable for the aftertreatment system 100.

[0021] In some embodiments, the aftertreatment system 100 may be associated with a hydrocarbon insertion assembly 125 for selectively injecting hydrocarbons (e.g., fuel) into an oxidation catalyst 120. The oxidation catalyst 120 may catalyze the ignition of hydrocarbons to increase the exhaust temperature, thereby regenerating the oxidation catalyst and / or other components within the housing 115. In some embodiments, the aftertreatment system 100 may also include a particulate filter 130 within the housing 115. In some embodiments, and as shown, the particulate filter 130 may be positioned downstream of the oxidation catalyst 120. In other embodiments, the particulate filter 130 may be positioned upstream of the oxidation catalyst 120. When positioned “upstream” of the oxidation catalyst 120, the particulate filter 130 may be positioned between the inlet duct 110 and the oxidation catalyst, such that exhaust gas exiting the particulate filter enters the oxidation catalyst. When positioned “downstream” of the oxidation catalyst 120, the particulate filter 130 may be positioned between the oxidation catalyst and a selective catalytic reduction (“SCR”) system 135, such that exhaust gas exiting the oxidation catalyst enters the particulate filter. In some embodiments, particulate filters may be disposed upstream and downstream of the oxidation catalyst 120.

[0022] The particulate filter 130 can be configured to remove particulate matter (e.g., soot, ash, debris, inorganic particles, etc.) from exhaust gas. The particulate filter can be any of a variety of filters suitable for use within the aftertreatment system 100. For example, in some embodiments, the particulate filter 130 can be a diesel particulate filter (“DPF”) with a ceramic filter (e.g., cordierite), and can be symmetrical or asymmetrical. In some embodiments, the particulate filter 130 can be catalytically activated. In some embodiments, the oxidation catalyst 120 and the particulate filter 130 can be integrated into a single component.

[0023] The housing 115 may also include an SCR system 135 configured to reduce components in the exhaust gas, such as nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons, etc. The SCR system 135 may include or be associated with a decomposition chamber 140 configured to receive reducing agent from a reducing agent storage tank 145 via a reducing agent insertion assembly 150. A reducing agent port 155 may be located on a side wall of the housing 115 to allow the insertion of reducing agent into the internal volume of the decomposition chamber 140. In some embodiments, the reducing agent port 155 may include a reducing agent injector configured to combine a stream of reducing agent received via the reducing agent port with compressed air and deliver the reducing agent-air combined stream or jet into the decomposition chamber 140. In some embodiments, the reducing agent injector may be a nozzle with a predetermined diameter. In other embodiments, other mechanisms may be used to selectively deliver reducing agent into the decomposition chamber 140. Therefore, the decomposition chamber 140 can be configured to receive exhaust gas and reducing agent, and to promote the mixing of exhaust gas and reducing agent to form an exhaust gas-reducing agent mixture. In some embodiments, a mixer, baffle, blade, or other structure can be used in conjunction with the decomposition chamber 140 to further promote the mixing of reducing agent and exhaust gas.

[0024] The decomposition chamber 140 can be configured to receive a reducing agent in various ways. For example, in some embodiments, the decomposition chamber 140 can be positioned upstream of the SCR system 135 to allow the reducing agent to be inserted into the decomposition chamber upstream of the SCR system via the reducing agent port 155. In other embodiments, the decomposition chamber 140 can be configured such that the reducing agent port 155 is configured to allow direct insertion of the reducing agent into the SCR system 135. In other embodiments, the decomposition chamber 140 can be disposed within the inlet conduit 110. Although in Figure 1 The decomposition chamber 140 is shown downstream of the oxidation catalyst 120, but the decomposition chamber may alternatively be located upstream of the oxidation catalyst, upstream or downstream of the particulate filter 130, and / or upstream of the SCR system 135.

[0025] The reducing agent injected into the decomposition chamber via reducing agent port 155 can be stored in reducing agent storage tank 145. The reducing agent promotes the decomposition of components of the exhaust gas (e.g., NOx gases included in the exhaust gas). Depending on the composition of the exhaust gas, any suitable reducing agent can be used. For example, in some embodiments, the exhaust gas may include diesel engine exhaust, and the reducing agent may include diesel exhaust fluid (e.g., diesel exhaust fluid sold under the name ADBLUE®), such as urea, an aqueous urea solution, or any other fluid including ammonia. When an aqueous urea solution is used as a reducing agent, the solution may include a specific ratio of urea to water. For example, in some embodiments, this ratio may be 32.5% volume of urea and 67.5% volume of deionized water, 40% volume of urea and 60% volume of deionized water, or any other suitable ratio of urea to deionized water. The reducing agent from reducing agent storage tank 145 can be selectively inserted into the decomposition chamber via reducing agent insertion assembly 150. The reducing agent insertion assembly 150 may include various structures to facilitate receiving reducing agent from the reducing agent storage tank 145 and supplying it to the reducing agent port 155. For example, the reducing agent insertion assembly 150 may include or be associated with various pumps, valves, screens, filters, etc., to control them, which facilitate receiving reducing agent from the reducing agent storage tank 145 and supplying it to the reducing agent port 155.

[0026] Furthermore, in some embodiments, the reducing agent can be inserted into the decomposition chamber in either liquid or gaseous form. In some embodiments, the reducing agent port 155 (particularly the reducing agent injector associated with the reducing agent port) can be configured to inject the reducing agent in liquid form. In such embodiments, the reducing agent port 155 can constitute a "wetdoser" or a "liquid feeder," or be part of a "wet feeder" or a "liquid feeder." In other embodiments, an evaporator can be associated with the reducing agent port 155, the reducing agent injector, and / or the reducing agent insertion assembly 150 to evaporate or convert the liquid reducing agent into a gaseous form before inserting it into the housing 115. Regardless of whether it is inserted in liquid or gaseous form, after being injected into the decomposition chamber, the reducing agent undergoes evaporation, pyrolysis, and / or hydrolysis to form gaseous ammonia, which is then mixed with exhaust gas to form an exhaust-reducing agent mixture. The exhaust-reducing agent mixture can then flow through the SCR catalyst 160 of the SCR system 135.

[0027] SCR catalyst 160 can be formulated to use gaseous ammonia as a reagent to decompose certain components in exhaust gas in the presence of an SCR catalyst. Specifically, SCR catalyst 160 catalyzes gaseous ammonia in exhaust gas, thereby reducing NOx in the exhaust gas during the oxidation reaction. In some embodiments, SCR catalyst 160 may include a metal-zeolite catalyst, including but not limited to a Cu-CHA-zeolite catalyst (e.g., a Cu-SSZ-13 catalyst), and may also include other zeolite structures, including Cu-SAPO-34 catalyst, Cu-LTA, Cu-AEI, Cu-ZSM, Cu-β, Cu-chabazite, or any other suitable catalyst. In other embodiments, SCR catalyst 160 may include a vanadium, iron-zeolite, or copper / iron-zeolite catalyst. In other embodiments, SCR catalyst 160 may include a multi-zone catalyst, for example, having a first zone including a copper-zeolite catalyst and a second zone including an iron-zeolite catalyst, or vice versa. The SCR catalyst 160 can be mounted on a suitable substrate, such as a monolithic core made of ceramic (e.g., cordierite) or metal (e.g., kanthal), which may define a honeycomb structure, for example. In some embodiments, a washcoat can also be used as a carrier material for the SCR catalyst 160. Such a washcoat material may include, for example, alumina, titanium dioxide, silica, any other suitable washcoat material, or a combination thereof. The monolithic core can be securely positioned in a canister to form an SCR system 135, which can be mounted in an aftertreatment system 100. In some embodiments, the SCR system 135 may include a selective catalytic reduction filter (SCRF). The treated exhaust gas (e.g., treated to reduce components such as NOx gases, unburned hydrocarbons, etc.) is discharged into the environment via an outlet duct 165.

[0028] In some embodiments, a heater 170 may also be disposed within the housing 115. The heater 170 can be used to heat exhaust gas to improve the efficiency of the aftertreatment system 100. In some embodiments, the heater 170 may be a resistance heater. In other embodiments, the heater 170 may be another type of electric heater. In further embodiments, the heater may include any device or mechanism that can be used to heat exhaust gas. In some embodiments, the heater 170 may be configured as a pulse-width modulation (PWM) heater, as PWM can be used to control the heater. In other embodiments, the heater 170 may be controlled in other ways. Furthermore, the positioning of the heater 170 may vary depending on the embodiment. For example, and as... Figure 1As shown, in some embodiments, heater 170 may be located upstream of oxidation catalyst 120. In some embodiments, heater 170 may be combined with or cross-coupled with oxidation catalyst 120 (e.g., combined with oxidation catalyst 120). In other embodiments, heater 170 may be located downstream of oxidation catalyst 120. For example, in some embodiments, heater 170 may be located between oxidation catalyst 120 and particulate filter 130. In other embodiments, heater 170 may be located downstream of particulate filter 130 and upstream of SCR system 135. In some embodiments, heater 170 may be combined with or cross-coupled with particulate filter 130. In further embodiments, heater 170 may be located within or cross-coupled with SCR system 135 (e.g., combined with SCR system 135). In further embodiments, heater 170 may be located within or cross-coupled with decomposition chamber 140 (e.g., combined with decomposition chamber 140), located upstream of decomposition chamber, or located downstream of decomposition chamber. Furthermore, in some embodiments, more than one heater located in different locations (e.g., heater 170) may be used.

[0029] Although the heater 170, oxidation catalyst 120, particulate filter 130, decomposition chamber 140, and SCR system 135 have been described as being housed within a single housing (e.g., housing 115), in some embodiments, one or more of these components may be housed in separate housings and operatively connected together. Furthermore, while a single instance of each of the heater 170, oxidation catalyst 120, particulate filter 130, decomposition chamber 140, and SCR system 135 has been described, in some embodiments, multiple instances of one or more of these elements may be provided within the aftertreatment system 100, if appropriate.

[0030] Still referencing Figure 1 The aftertreatment system 100 also includes a controller 175 configured to control the operation of various components of the aftertreatment system 100 during exhaust gas treatment. For example, the controller 175 may be operatively connected to the reducing agent insertion assembly 150 to instruct the reducing agent insertion assembly to selectively deliver reducing agent from the reducing agent storage tank 145 to the reducing agent port 155. The controller 175 may also be operatively connected to the reducing agent port 155 to selectively operate the reducing agent port to insert reducing agent received from the reducing agent storage tank 145 into the decomposition chamber 140. Therefore, the controller 175 can control the reducing agent feed rate via the reducing agent insertion assembly 150 and the reducing agent port 155.

[0031] The controller 175 can also be configured to control the hydrocarbon insertion assembly 125 to selectively insert hydrocarbons into the oxidation catalyst 120 (e.g., when regeneration of the oxidation catalyst 120 and / or particulate filter 130 is required). In some embodiments, selective hydrocarbon insertion can also be used to increase exhaust temperature. Thus, in some embodiments, the hydrocarbon insertion assembly 125 can be used in conjunction with the heater 170 to increase exhaust temperature. In some embodiments, the controller 175 can be used to detect an increased fuel consumption rate within the engine 105, as discussed in more detail below. The controller 175 can also be connected to other components of the aftertreatment system 100 controlled by the controller. The controller 175 can be operatively coupled to various components of the aftertreatment system 100 using any type and any number of wired and / or wireless connections. For example, in some embodiments, wired connections (such as serial cables, fiber optic cables, CAT5 cables, etc.) can be used to communicatively connect the controller 175 to one or more components of the aftertreatment system 100. In other embodiments, wireless connections such as the Internet, Wi-Fi, cellular, radio, Bluetooth, ZigBee, etc., can be used. In some embodiments, a combination of wired and wireless connections may be used. Furthermore, in some embodiments, a Controller Area Network (CAN) bus may provide the exchange of signals, information, and / or data between the controller 175 and various components of the post-processing system 100.

[0032] Controller 175 may include one or more processing units or processors, or be associated with them. Processing units may include microprocessors, programmable logic controller (PLC) chips, application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), digital signal processors (DSPs), a set of processing units, or other suitable electronic processing units. The processing units of controller 175 may be configured to execute computer-readable instructions for performing the operations described herein. Processing units may be implemented in hardware, firmware, software, or any combination thereof. "Executing computer-readable instructions" means that the processing unit can perform the operations required by those instructions. The processing unit may retrieve instructions from memory associated with controller 175 for execution and copy the instructions in executable form to physical memory. In some embodiments, the processing unit may be configured to execute instructions without first copying them to physical memory. Instructions may be written using one or more programming languages, scripting languages, assembly languages, etc. Therefore, controller 175, via its associated processing units, may be configured to execute instructions, algorithms, commands, or programs stored in memory associated with the controller.

[0033] While a single controller (e.g., controller 175) is shown configured to control multiple elements of the aftertreatment system 100 (e.g., reducing agent insertion assembly 150, hydrocarbon insertion assembly 125, heater 170, etc.), in some embodiments, separate controllers may be used for one or more of these elements. Controller 175 may include, or be associated with, other hardware, software, and / or firmware components that may be required or considered useful in performing the functions described herein. In some embodiments, controller 175 may be part of an electronic control unit (ECU) of the aftertreatment system 100. Controller 175 may be configured to control the reducing agent insertion assembly 150, hydrocarbon insertion assembly 125, heater 170, and any other elements of the aftertreatment system 100 controlled by the controller based on data received from one or more sensors, such as sensors 180A, 180B, 180C, 180D, 180E, and 180F.

[0034] Each of sensors 180A through 180F can be configured to measure one or more conditions. For example, in some embodiments, sensor 180A may be located within the engine and configured to measure one or more engine parameters (e.g., engine speed, engine temperature, engine load, vehicle speed, etc.). Sensor 180B may be located within inlet duct 110 to measure one or more parameters of exhaust gas flowing through the inlet duct. Sensors 180C and 180D may be configured to measure one or more parameters of exhaust gas at the inlet and outlet of particulate filter 130, respectively. Sensor 180E may be configured to measure one or more parameters at the outlet of SCR system 135, while sensor 180F may be configured to measure one or more parameters of exhaust gas flowing through outlet duct 165.

[0035] In some embodiments, one or more of sensors 180A-180F may include a NOx sensor configured to measure the amount of NOx gas in the exhaust gas. In other embodiments, one or more of sensors 180A-180F may include a temperature sensor to measure the temperature of the exhaust gas. In still other embodiments, one or more of sensors 180A-180F may include a pressure sensor, an oxygen sensor, a particulate matter sensor, an ammonia sensor (e.g., for determining ammonia slip), or any other sensor for measuring parameters that the controller 175 may need or is considered desirable to have when controlling various components of the aftertreatment system 100 and to achieve a target temperature at the inlet of the SCR system 135. Furthermore, while individual sensors (e.g., sensors 180A-180F) are shown in various locations, in some embodiments, multiple sensors may be positioned at these locations. Additionally, in some embodiments, each of sensors 180A-180F may be configured to measure a single parameter (e.g., temperature, NOx amount, etc.), while in other embodiments, each of these sensors may be configured to measure multiple parameters. In addition, each of Sensors 180A-180F can be a physical sensor (e.g., a hardware device such as a thermistor) or a virtual sensor (e.g., the value of the parameter to be measured is determined based on a software model).

[0036] Although sensors 180A-180F are shown positioned in specific locations within the aftertreatment system 100, the positioning of these sensors can be appropriately varied. For example, while sensor 180C is shown mounted at the inlet of particulate filter 130, in some embodiments, this sensor can be positioned anywhere between the outlet of oxidation catalyst 120 and the inlet of particulate filter. Similarly, while sensor 180D is shown mounted at the outlet of particulate filter 130, in some embodiments, this sensor can be mounted anywhere between the outlet of particulate filter and the inlet of SCR system 135. Likewise, the positions of other sensors can be varied. Furthermore, although in Figure 1 Only sensors 180A-180F are shown in this document; however, in other embodiments, additional sensors may be mounted in other locations as needed to enable controller 175 to perform the functions described herein. Each of sensors 180A-180F can be configured to collect data and send that data to controller 175. Based on the collected data, controller 175 can then control the operation of post-processing system 100.

[0037] Although Figure 1Certain components of the aftertreatment system 100 are shown and described, but the aftertreatment system may include other or additional elements that may be suitable. For example, in some embodiments, the aftertreatment system 100 may include an ammonia slip catalyst (“ASC”) or an ammonia oxidation catalyst (“AMOx”) to reduce ammonia slip, in which ammonia not catalyzed by the SCR catalyst 160 may be decomposed. In some embodiments, the aftertreatment system 100 may include a mixer, baffles, a secondary filter (e.g., a secondary partial flow or catalytic filter), or any other components that may be required or considered desirable for proper operation of the aftertreatment system 100.

[0038] Turning Figure 2 This diagram illustrates an example flowchart outlining the operation of process 200 according to some embodiments of the present disclosure. Process 200 can be used to detect an increased or abnormal fuel consumption rate in engine 105. An increased or abnormal fuel consumption rate can indicate increased or excessive ash and / or soot loading or accumulation in particulate filter 130. If the fuel consumption rate in engine 105 (e.g., the amount of fuel consumed per unit time) exceeds a predetermined threshold or is greater than the fuel consumption rate in a normal (standard / healthy) engine, the fuel consumption can be considered "increased" or "abnormal". Excessive ash and / or soot accumulation can hinder the optimal operation of engine 105. For example, excessive ash and / or soot accumulation can indicate wear and tear on certain components of engine 105. Therefore, by identifying an increased fuel consumption rate in engine 105, excessive accumulation of ash and / or soot in particulate filter 130 can be identified, and the particulate filter and / or worn engine components can be repaired / replaced in a timely manner to maintain optimal operation of engine 105.

[0039] Process 200 can be implemented by controller 175. Therefore, after starting operation 205, controller 175 receives a first calibration table at operation 210. In some embodiments, the first calibration table may be compiled in tabular or other form. In some embodiments, the first calibration table may be an ash loading calibration table. In other embodiments, the first calibration table may be a soot and ash loading calibration table (e.g., a delta pressure soot loaded estimate table (DPSLE)). The ash loading calibration table and the soot and ash loading calibration table may respectively correlate the ash accumulation rate or the ash and soot accumulation rate with the pressure drop across particulate filter 130. For example, the ash loading calibration table may be configured to correlate the pressure drop across particulate filter 130 with the ash accumulation rate in the particulate filter. In some embodiments, as the ash accumulation rate in the particulate filter 130 increases, the pressure drop across the particulate filter increases. Similarly, in some embodiments, the soot and ash loading calibration table may be configured to correlate the pressure drop across particulate filter 130 with the ash and soot accumulation rate in the particulate filter. In some embodiments, as the rate of carbon soot and ash accumulation in the particulate filter 130 increases, the pressure drop across the particulate filter increases.

[0040] Furthermore, in some embodiments, ash loading calibration tables and soot and ash loading calibration tables can be created by testing (e.g., transient testing) the operation of a normal (e.g., standard / healthy / normally operating) engine 105 and / or modeling the operation of the normal engine 105 to measure the pressure drop across the particulate filter 130 for different levels of ash and / or soot accumulation rates and exhaust flow rates. For example, to create an ash loading calibration table, the pressure drop across a clean particulate filter (e.g., particulate filter 130) can be measured. In some embodiments, the pressure drop across the particulate filter 130 can be measured by measuring the pressure at which exhaust gas enters the particulate filter (e.g., inlet pressure) and the pressure at which exhaust gas exits the particulate filter (e.g., outlet pressure), and calculating the difference between the outlet pressure and the inlet pressure.

[0041] After measuring the pressure drop across a clean particulate filter (e.g., a particulate filter with no ash and no soot, or with ash and / or soot below a predetermined threshold), particulate filter 130 can be filled with calcined gypsum to simulate the ash accumulation rate on particulate filter 130 during the operation of a conventional engine. Different amounts of calcined gypsum can be filled to simulate different ash accumulation rates and exhaust flow rates during the operation of a conventional engine. For each ash accumulation rate (e.g., the amount of ash accumulated per unit time), the pressure drop across particulate filter 130 can be measured. Based on the measured pressure drop and the corresponding ash accumulation rate, a calibration table (e.g., an ash loading calibration table) can be developed. Therefore, an ash loading calibration table can include multiple ash accumulation rates and corresponding pressure drops across particulate filter 130 for various exhaust flow rates. In other embodiments, the ash loading calibration table can be created in other ways. For example, in some embodiments, field-returned components from actual testing can be used to create the ash loading calibration table. In some embodiments, ash can be artificially loaded with alternative powders (e.g., calcium sulfate, etc.), ash blown in from field return components, and other mechanisms can be used to create an ash loading calibration table.

[0042] Similarly, in some embodiments, ash and soot loading calibration tables can be developed. An ash loading calibration table considers only the ash accumulation rate in particulate filter 130, while an ash and soot loading calibration table considers both the ash accumulation rate and the soot accumulation rate in the particulate filter. In some embodiments, a soot and ash loading calibration table can be created in a similar manner to an ash loading calibration table, using an amount of calcined gypsum (or another mechanism) to simulate the ash accumulation rate and the soot accumulation rate. In other embodiments, calcined gypsum can be used to simulate the ash accumulation rate, while another element can be used to simulate the soot accumulation rate in particulate filter 130. An example of creating a soot and ash loading calibration table (particularly during low or idle operation) is discussed in U.S. Patent No. 10,273,858, filed December 2, 2015, the entire contents of which are incorporated herein by reference. Therefore, a soot and ash loading calibration table can include multiple soot and ash accumulation rates for various exhaust flow rates and corresponding pressure drops across particulate filter 130.

[0043] Once the ash loading calibration table and the soot and ash loading calibration table are created, these tables can be input into the controller 175. In some embodiments, the ash loading calibration table and the soot and ash loading calibration table can be periodically adjusted and updated, and the updated table can replace the old table input into the controller 175. Therefore, at operation 210, the controller 175 receives the first calibration table (e.g., the ash loading calibration table and / or the soot and ash loading calibration table).

[0044] At operation 215, controller 175 receives a second calibration table. The second calibration table may include an estimated fuel consumption rate in engine 105 and a corresponding ash accumulation rate in the particulate filter 130 of a normal (e.g., standard / healthy / normally operating) engine. In some embodiments, the ash / smoke accumulation rate determined by the first calibration table at operation 210 may be easily variable. For example, in some embodiments, the amount of ash accumulation may vary based on engine operation. Some engine operations may result in more ash accumulation than others. In some embodiments, engine speed, load, and duty cycle may also affect the amount of ash accumulation. In some embodiments, the amount of ash deposited in the particulate filter 130 may increase with wear of certain engine components. Similarly, other factors may affect ash accumulation in the particulate filter 130. The ash loading calibration table configured based on exhaust flow rate and pressure drop across the particulate filter 130, as well as the soot and ash loading calibration tables, do not take into account these other factors that may affect ash accumulation.

[0045] Therefore, in some embodiments, a correction factor may be used to improve the accuracy of the ash loading calibration table and the soot and ash loading calibration table. The correction factor can be used to accurately determine ash accumulation in the particulate filter 130 (or at least increase the accuracy of ash accumulation). In some embodiments, the correction factor may be based on a second calibration table. Generally, the fuel (e.g., engine oil) used in the engine 105 may have some ash content. When the fuel burns, most of the ash from the fuel escapes and deposits in the particulate filter 130. In some embodiments, the fuel consumption rate may indicate one or more factors that may affect the rate of ash accumulation in the particulate filter 130. For example, the fuel consumption rate increases as components of the engine 105 wear. Furthermore, the fuel consumption rate increases as engine load, engine speed, etc., increase. As the fuel consumption rate increases, the rate of ash accumulation in the particulate filter 130 also increases, and vice versa. Therefore, in some embodiments, increased or excessive ash and / or soot accumulation in the particulate filter 130 can be detected by detecting an increased or abnormal fuel consumption rate.

[0046] Therefore, at operation 215, a second calibration table is created and received by controller 175. In some embodiments, the second calibration table may be compiled in tabular or other form. In some embodiments, the second calibration table may be based on the duty cycle of engine 105. For example, in some embodiments, for various duty cycles of engine 105, a corresponding estimated fuel consumption rate may be determined. For each duty cycle, an estimated total ash accumulation rate in particulate filter 130 may also be determined. The second calibration table may then include various estimated fuel consumption rates for each duty cycle and corresponding estimated total ash accumulation rates. Figure 3The creation of the second calibration table is explained. Once the second calibration table is received at operation 215, at operation 220, controller 175 determines whether soot accumulation should be considered when identifying an increased or abnormal fuel consumption rate.

[0047] Soot is carbon-based and can be burned off at higher temperatures. For example, soot on the particulate filter 130 can be burned off by regenerating it (e.g., by increasing the temperature on the particulate filter). Ash is inorganic in nature and may not be burned off at higher temperatures. Therefore, ash cannot typically be removed by regenerating the particulate filter 130. In some embodiments, it may be necessary to replace the particulate filter 130 or remove the particulate filter to clean the deposited ash. In some embodiments, it may be desirable to determine an increased or abnormal fuel consumption rate based solely on ash accumulation. In other embodiments, it may be desirable to determine an increased or abnormal fuel consumption rate based on both ash and soot. Therefore, at operation 220, the controller 175 determines whether soot accumulation should be considered when determining an increased or abnormal fuel consumption rate.

[0048] In some embodiments, controller 175 may be pre-programmed to determine the fuel consumption rate in the presence or absence of soot accumulation. In other embodiments, controller 175 may receive user input indicating whether soot accumulation should be considered in determining an increased or abnormal fuel consumption rate. In other embodiments, controller 175 may determine whether soot accumulation should be considered in other ways. If controller 175 determines that an increased or abnormal fuel consumption rate should be determined without considering soot accumulation, at operation 225, particulate filter 130 is regenerated to remove soot from the particulate filter. As described above, in some embodiments, particulate filter 130 can be regenerated by increasing the temperature on the particulate filter. In some embodiments, the temperature on particulate filter 130 can be increased by heating the exhaust gas (e.g., using heater 170), by injecting additional fuel into the exhaust gas (e.g., using hydrocarbon insertion assembly 125), or in any other way. In some embodiments, particulate filter 130 can be regenerated in other ways.

[0049] If at operation 220 the controller 175 determines that soot accumulation should be considered when determining the fuel consumption rate, the particulate filter 130 is not regenerated, and process 200 proceeds to operation 230. Therefore, if soot accumulation is not considered when determining an increased or abnormal fuel consumption rate, the process proceeds from operation 225 to operation 230; or if soot accumulation is considered when determining an increased or abnormal fuel consumption rate, the process proceeds directly from operation 220 to operation 230. At operation 230, the controller 175 measures the actual pressure drop across the particulate filter 130. In some embodiments, the controller 175 may use sensor 180C to measure the actual pressure of the exhaust gas at the inlet of the particulate filter 130 (e.g., inlet pressure). Similarly, in some embodiments, the controller 175 may use sensor 180D to measure the actual pressure of the exhaust gas at the outlet of the particulate filter 130 (e.g., outlet pressure). The controller 175 can then calculate the difference between the inlet and outlet pressures to determine the actual pressure drop across the particulate filter 130 (also referred to herein as back pressure).

[0050] At operation 235, controller 175 determines the expected total ash accumulation rate (e.g., ash content per unit time) in particulate filter 130 during engine 130 operation. In some embodiments, the expected total ash accumulation rate may be determined based on a second calibration table from operation 215. For example, in some embodiments, controller 175 may determine the current duty cycle of engine 105 (e.g., the engine duty cycle when process 200 is executed). Based on the current duty cycle of engine 105, controller 175 may determine the expected total ash accumulation rate. Reference is made below. Figure 4 The process for determining the expected total ash accumulation rate is discussed in more detail.

[0051] Once the expected total ash accumulation rate is determined at operation 235, controller 175 calculates the expected pressure drop across particulate filter 130 at operation 240. Specifically, in some embodiments, controller 175 determines the expected pressure drop based on a first calibration table from operation 210. In some embodiments, if soot accumulation is taken into account (e.g., as determined at operation 220), an ash and soot loading calibration table can be used to determine the expected pressure drop. If only ash accumulation is taken into account (e.g., as determined at operation 220), an ash loading calibration table can be used to determine the expected pressure drop. To determine the expected pressure drop from either the ash loading calibration table or the soot and ash loading calibration table, controller 175 maps the expected total ash accumulation rate from operation 235 to the corresponding pressure drop. In other words, controller 175 can perform a lookup of the expected total ash accumulation rate in the first calibration table and determine the pressure drop corresponding to (or closest to) the expected total ash accumulation rate.

[0052] At operation 245, controller 175 compares the expected pressure drop determined at operation 240 with the actual pressure drop measured at operation 230. If the actual pressure drop is greater than the expected pressure drop, controller 175 determines at operation 250 that the engine has an increased or abnormal fuel consumption rate. In some embodiments, controller 175 may issue an alarm or indicator to indicate an increased or abnormal fuel consumption rate. As described above, an increased or abnormal fuel consumption rate may indicate increased or excessive ash and / or soot accumulation in particulate filter 130. The alarm or indicator may be an instruction to the user to repair or replace particulate filter 130. The alarm or indicator may also be an instruction to the user that certain parts of engine 105 may be wearing out and require repair. Therefore, engine 105 can be repaired to avoid damage and shortened lifespan of particulate filter 130 and any affected components. Timely diagnosis of excessive ash and / or soot accumulation can also prevent an increased fuel consumption rate, which may lead to reduced operation of particulate filter 130 and increased costs that may require more frequent refueling. In some embodiments, signs or alerts may be provided via telematics communication on the dashboard or other electronic devices within the vehicle. In some embodiments, alerts or signs may be sent to a fleet manager or other personnel.

[0053] If, at operation 245, controller 175 determines that the actual pressure drop is less than or equal to the expected pressure drop, the controller determines that the fuel consumption rate is normal. Process 200 ends at operation 255. In some embodiments, process 200, and at least operations 225-250, may be repeated periodically or when certain conditions are met. For example, in some embodiments, process 200 may be repeated whenever an updated first or second calibration table is entered into controller 175. In some embodiments, process 200 may be repeated after a specified number of miles or a specified period of time has been traveled by the vehicle. In some embodiments, process 200 may be run after each cleaning, regeneration, or replacement of particulate filter 130. In some embodiments, process 200 may be run on demand. In other embodiments, process 200 or at least a portion thereof may be performed when other conditions are met. Thus, in some embodiments, process 200 may be used for diagnostic monitoring to determine excessive ash and / or soot accumulation in particulate filter 130 in real-time or substantially real-time.

[0054] Now for reference Figure 3This illustrates an example flowchart outlining the operation of process 300 according to some embodiments of the present disclosure. Process 300 can be used to create a second calibration table for operation 215. In some embodiments, process 300 may be implemented by controller 175. As described above, fuel consumption rate increases with increasing ash accumulation rate and vice versa. In some embodiments, a reference or estimated fuel consumption rate (e.g., fuel consumption per unit time) can be measured at a standard duty cycle of a normal (e.g., healthy, standard, normally operating) engine. Engine 105 can be considered “normal” if there is no ash and / or soot accumulation in the particulate filter or if the ash and / or soot accumulation rate is below a predetermined threshold. Furthermore, in some embodiments, the ash accumulation rate in the particulate filter 130 can also be measured for a standard duty cycle.

[0055] Therefore, after starting operation 305, controller 175 determines the fuel consumption rate at various standard duty cycles at operation 310. In some embodiments, the “duty cycle” of engine 105 can be a function of engine speed and workload conditions under which the engine operates in a particular application. Therefore, in some embodiments, the standard duty cycle can depend on engine speed and workload. In some embodiments, the standard duty cycle can be classified as low, medium, and high duty cycles. In some embodiments, whether the duty cycle is classified as low, medium, or high can depend on engine speed (e.g., in revolutions per minute (RPM)) and workload (e.g., torque measured in Newton-meters). In some embodiments, engine speeds greater than a first threshold and / or workloads greater than a second threshold can be classified as high duty cycles. In some embodiments, engine speeds greater than a third threshold but less than a first threshold and / or workloads greater than a fourth threshold but less than a second threshold can be classified as medium duty cycles. In some embodiments, engine speeds less than a third threshold and / or workloads less than a fourth threshold can be classified as low duty cycles. For example, in some embodiments, engine speed and / or workload during highway cruising or pick-up and delivery can be considered low duty cycles. Standard mixed city and highway transient cycles (e.g., Federal Transient Protocol Cycles or World Harmonized Transient Cycles) can be considered medium duty cycles, while high-load cycles (e.g., Ramped Mode Cycles, World Harmonized Stationary Cycles, etc.) can be considered high duty cycles. In other embodiments, fuel consumption rates can be determined using steady-state duty cycle tests that include discrete duty cycles (examples of which are given in...). Figure 5A (As shown in the diagram). Therefore, controller 175 can receive various duty cycles during which fuel consumption rate is to be determined.

[0056] Furthermore, generally speaking, fuel consumption rate increases with engine speed. Similarly, fuel consumption rate also increases with workload. Therefore, at operation 310, the estimated fuel consumption rate of a normal engine is measured during various duty cycles (e.g., low, medium, and high duty cycles) at which the estimated fuel consumption rate is to be measured. In some embodiments, the estimated fuel consumption rate can be measured by using a dipstick and filling back to a consistent fill level to measure how much fuel has been added to the normal engine. The estimated fuel consumption rate can be used as a measure of normal engine operation. The measured fuel consumption rate can be measured relative to the estimated fuel consumption rate to determine an increase in fuel consumption and to indicate engine maintenance. The estimated fuel consumption rate can be input into controller 175. The normal engine used to determine the estimated fuel consumption rate during various duty cycles can be considered a "test unit". In other embodiments, the estimated fuel consumption rate can be determined in other ways. Therefore, at operation 310, controller 175 receives various duty cycles and estimated fuel consumption rates for these duty cycles, and creates a first table of estimated fuel consumption rates at the various duty cycles. In some embodiments, the first table may include estimated fuel consumption rates for multiple engine speeds and multiple workloads. Figure 5A An example of the first table is shown in the image.

[0057] At operation 315, controller 175 determines the estimated ash accumulation rate during various standard duty cycles in the test unit. Specifically, for each duty cycle for which the estimated fuel consumption rate is determined at operation 310, the estimated ash accumulation rate for that duty cycle can also be determined (e.g., by extending the test (e.g., >50 hours)). In some embodiments, the estimated ash accumulation rate can be determined by weighing the particulate filter 130. In some embodiments, the particulate filter 130 can be regenerated before weighing to remove any deposited soot to obtain a more accurate measurement of ash accumulation. In some embodiments, the weight of a clean particulate filter (e.g., in the absence of a new particulate filter) can be subtracted from the total weight of the particulate filter 130 with ash deposits to obtain the total weight of ash accumulated on the particulate filter 130. Therefore, the particulate filter 130 can be weighed before ash loading, then the particulate filter 130 can be loaded with ash, and weighed again. The increased weight can be determined based on the increased weight of the particulate filter 130 due to the loading of ash. Therefore, based on the total weight of ash accumulation, an estimated ash accumulation rate (e.g., in grams per mile) can be determined. Thus, an estimated ash accumulation rate can also be determined for each duty cycle for which the estimated fuel consumption rate is determined. The estimated ash accumulation rate can be input into controller 175. In some embodiments, fuel (e.g., diesel) may also contribute to ash accumulation in particulate filter 130. Therefore, in some embodiments, additional ash content can be added to the estimated ash accumulation rate to account for the ash contribution from fuel. In some embodiments, the ash accumulation rate from fuel for each duty cycle can be known. The ash accumulation rate from fuel for each duty cycle can be input into controller 175. Therefore, in some embodiments, the estimated total ash accumulation rate for each duty cycle can be the sum of the estimated ash accumulation due to fuel consumption and the ash accumulation rate due to fuel. Once the estimated total ash accumulation rate is calculated, controller 175 can create a second table of various duty cycles and corresponding estimated total ash accumulation rates. In some embodiments, for multiple engine speeds and multiple workloads, the second table may include corresponding estimated total ash accumulation rates. Figure 5B An example of the second table is shown in the image.

[0058] At operation 320, controller 175 creates a third table of estimated fuel consumption and estimated total ash accumulation rates for various duty cycles. The first table from operation 310 is between various duty cycles and estimated fuel consumption rates. The second table from operation 315 is between the same duty cycle used in the first table and estimated total ash accumulation rates. Controller 175 then associates the first and second tables to create a second calibration table, which includes estimated fuel consumption rates and corresponding estimated total ash accumulation rates for each duty cycle (e.g., various low, medium, and high duty cycles). In some embodiments where the first and second tables are created for low, medium, and high duty cycles, the third table may not be necessary. In some embodiments, the third table may be a conversion table from duty cycle severity to fuel consumption rate. For example, in some embodiments, if the first and second tables are created based on steady-state duty cycles, the third table can convert steady-state duty cycles to low, medium, and high duty cycles. For example, in some embodiments, the fuel consumption rate can be calculated directly by averaging the fuel consumption rate per second based on speed and / or workload (e.g., torque) over a period of time. In some embodiments, calibration can be performed by summing the total fuel consumption rate using only speed and / or workload per second. In some embodiments, the second and third tables (when created) can be created simultaneously, or the third table can be created before or after the second table.

[0059] Figure 3 The second calibration table can then be used to determine the expected total ash accumulation at operation 235, as shown in the reference below. Figure 4 To be discussed in more detail.

[0060] In some embodiments, speed and torque can be used to establish a duty cycle severity rating to measure the relationship between fuel consumption rate and speed / torque during the design process. In some embodiments, controller 175 can use this relationship to add a weighting factor to the estimated ash accumulation (and therefore fuel consumption) rate to account for possible differences in vehicle operation or mixed duty cycles. For example, in some embodiments, the weighting factor may be based on light, normal, and severe duty cycles and may be equivalent to ash accumulation rates of approximately 50%, 100%, and 150%, respectively. In some embodiments, the weighting factor may be particularly useful during mixed duty cycles. For example, a vehicle may switch between various duty cycles during operation. Therefore, vehicle operation may include mixed duty cycles. In this case, a weighting factor can be used to reflect the mixed duty cycle. The accumulated ash accumulation (summation) can be continuously tracked based on vehicle speed and / or hours of operation. In some embodiments, the weighting factor may be an interpolation of engine work (e.g., speed / torque) over a period of time between low, medium, and high duty cycles. For example, in some embodiments, if a low duty cycle is defined as 10 hp-h, a medium duty cycle as 20 hp-h, and a high duty cycle as 30 hp-h, and each of these duty cycles has an associated fuel (and ash) consumption rate, then if the current duty cycle of engine 105 is 15 hp-h, the fuel consumption rate could be the average of the fuel consumption rates corresponding to the low and medium duty cycles (since the current duty cycle falls between the low and medium duty cycles). In other embodiments, functions other than averaging can be used as weighting factors to determine the fuel consumption rate for a mixed duty cycle.

[0061] Now go to Figure 4 This diagram shows an example flowchart outlining the operation of process 400 according to some embodiments of the present disclosure. Process 400 can be used to determine the expected total ash accumulation rate during engine operation at operation 235. Process 400 can be implemented by controller 175. Thus, after operation 405 begins, controller 175 determines the current duty cycle of engine 105 at operation 410. In some embodiments, engine 105 may have one or more sensors that can be used to determine the engine's duty cycle. In other embodiments, controller 175 may measure the engine speed of engine 105 and the torque in the engine to determine the workload. Based on the engine speed and torque, controller 175 can determine the duty cycle.

[0062] At operation 415, controller 175 determines the expected fuel consumption rate based on the duty cycle determined in operation 410. Specifically, in some embodiments, controller 175 estimates the expected fuel consumption rate based on the percentage of time spent in low, medium, and high duty cycles. For example, in some embodiments, controller 175 may determine engine speed and / or workload based on the current duty cycle and use engine speed and / or workload to identify the fuel consumption rate corresponding to that engine speed and / or workload from the first table in operation 310. At operation 420, controller 175 determines the expected total ash accumulation rate based on the determined fuel consumption rate. Specifically, controller 175 may estimate the ash loading rate based on the fuel consumption rate via directly measured values ​​or historically established rates. For example, in some embodiments, controller 175 may refer to a third table in operation 320 to look up the estimated total ash accumulation rate corresponding to the expected fuel consumption rate determined at operation 415. In some embodiments, instead of separate operations 415 and 420, controller 175 can determine the expected total ash accumulation rate from a second table by identifying an estimated total ash accumulation rate corresponding to the current duty cycle of engine 105. Process 400 ends at operation 425.

[0063] refer to Figure 5A and Figure 5B According to some embodiments of this disclosure, example tables are shown relating duty cycle (e.g., engine speed and workload) to estimated fuel consumption rate and estimated total ash accumulation rate. Specifically, Figure 5A Example table 500 (e.g., the first table of operation 310) shows the relationship between duty cycle and estimated fuel consumption rate, while Figure 5B Example Table 505 (e.g., the second table in Operation 315) shows the relationship between duty cycle and estimated total ash accumulation rate. See also: Figure 5A Table 500 displays engine speed in RPM on the X-axis 510 and workload in torque on the Y-axis 515. Value 520 in Table 500 corresponds to the estimated fuel consumption rate. Therefore, for a specific engine speed and workload, the estimated fuel consumption rate can be determined from Table 500. See details... Figure 5B Table 505 displays engine speed in RPM on the X-axis 525 and workload in torque on the Y-axis 530. The values ​​on X-axis 525 are the same as those on X-axis 510, and the values ​​on Y-axis 530 are the same as those on Y-axis 515. The value 535 in Table 505 corresponds to the estimated total ash accumulation rate. Therefore, for a specific engine speed and workload, the estimated total ash accumulation rate can be determined from Table 505.

[0064] Therefore, this disclosure utilizes the pressure drop across the particulate filter 130 and the predicted ash and soot (or ash only) loading response from a calibration table to determine when engine operating components may be worn, or when engine operation may be abnormal. The controller 175 can compare the pressure drop characteristics that change over time with an adjusted calibration table to determine when the ash accumulation rate is excessive, which can then be used to flag potential engine (e.g., cylinder) problems that increase fuel consumption before a full overhaul of the particulate filter 130 may be required.

[0065] Therefore, in some embodiments, this disclosure provides an aftertreatment system having a particulate filter and a controller, the particulate filter being configured to receive exhaust gas from an engine, the controller executing computer-readable instructions stored in a memory to: determine an actual pressure drop across the particulate filter based on pressure measurements across the particulate filter; determine an expected total ash accumulation rate in the particulate filter based on the current duty cycle of the engine; determine an expected pressure drop across the particulate filter based on the expected total ash accumulation rate; compare the expected pressure drop with the actual pressure drop; and determine, based on the comparison, whether the fuel consumption rate in the engine is abnormal.

[0066] In some embodiments, the controller further executes computer-readable instructions to determine a expected pressure drop based on a first calibration table. In some embodiments, the first calibration table includes a soot and ash loading calibration table that includes multiple pressure drops across the test particulate filter and a corresponding soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. In some embodiments, the first calibration table includes an ash loading calibration table that includes multiple pressure drops across the test particulate filter and a corresponding ash accumulation rate in the test particulate filter at each of the multiple pressure drops.

[0067] In some embodiments, the controller further executes computer-readable instructions to determine a expected total ash accumulation rate based on a first calibration table and a second calibration table. In some embodiments, the first calibration table includes a plurality of pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and a corresponding second ash accumulation rate at each of the plurality of duty cycles. In some embodiments, the first calibration table includes a plurality of pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and an estimated fuel consumption rate corresponding to each of the plurality of duty cycles. In some embodiments, the second calibration table further includes an additional calibration table including a corresponding second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

[0068] In some embodiments, the controller also executes computer-readable instructions to determine that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and to determine that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

[0069] This disclosure also provides a method comprising: determining an actual pressure drop across a particulate filter by a controller of an aftertreatment system based on pressure measurements across a particulate filter configured to receive exhaust gas from an engine; determining an expected total ash accumulation rate in the particulate filter by the controller based on the current duty cycle of the engine; determining an expected pressure drop across the particulate filter by the controller based on the expected total ash accumulation rate; comparing the expected pressure drop with the actual pressure drop by the controller; and determining whether the fuel consumption rate in the engine is abnormal based on the comparison.

[0070] In some embodiments, the method further includes a controller determining a desired pressure drop based on a first calibration table. In some embodiments, the first calibration table includes a soot and ash loading calibration table, which includes multiple pressure drops across the test particulate filter and a corresponding soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. In some embodiments, the first calibration table includes an ash loading calibration table, which includes multiple pressure drops across the test particulate filter and a corresponding ash accumulation rate in the test particulate filter at each of the multiple pressure drops.

[0071] In some embodiments, the method further includes a controller determining a projected total ash accumulation rate based on a first calibration table and a second calibration table. In some embodiments, the first calibration table includes a plurality of pressure drops across a test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and a corresponding second ash accumulation rate at each of the plurality of duty cycles. In some embodiments, the first calibration table includes a plurality of pressure drops across a test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and an estimated fuel consumption rate corresponding to each of the plurality of duty cycles. In some embodiments, the second calibration table further includes an additional calibration table including a corresponding second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

[0072] In some embodiments, the method further includes the controller determining that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and determining that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

[0073] This disclosure also provides a non-transitory computer-readable medium including computer-readable instructions stored thereon, which, when executed by a controller of an aftertreatment system, cause the controller to perform a process comprising: determining an actual pressure drop across a particulate filter based on pressure measurements across the particulate filter configured to receive exhaust gas from an engine; determining an expected total ash accumulation rate in the particulate filter based on the current duty cycle of the engine; determining an expected pressure drop across the particulate filter based on the expected total ash accumulation rate; comparing the expected pressure drop with the actual pressure drop; and determining, based on the comparison, whether the fuel consumption rate in the engine is abnormal.

[0074] In some embodiments, the controller further executes computer-readable instructions to determine a expected pressure drop based on a first calibration table. In some embodiments, the first calibration table includes a soot and ash loading calibration table that includes multiple pressure drops across the test particulate filter and a corresponding soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. In some embodiments, the first calibration table includes an ash loading calibration table that includes multiple pressure drops across the test particulate filter and a corresponding ash accumulation rate in the test particulate filter at each of the multiple pressure drops.

[0075] In some embodiments, the controller further executes computer-readable instructions to determine a expected total ash accumulation rate based on a first calibration table and a second calibration table. In some embodiments, the first calibration table includes a plurality of pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and a corresponding second ash accumulation rate at each of the plurality of duty cycles. In some embodiments, the first calibration table includes a plurality of pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the plurality of pressure drops, and wherein the second calibration table includes a plurality of duty cycles and an estimated fuel consumption rate corresponding to each of the plurality of duty cycles. In some embodiments, the second calibration table further includes an additional calibration table including a corresponding second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

[0076] In some embodiments, the controller also executes computer-readable instructions to determine that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and to determine that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

[0077] It should be noted that the term "example" used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations and / or illustrations of possible embodiments (and such terms are not intended to mean that such embodiments must be particular or excellent examples).

[0078] As used herein, the term “about” generally means plus or minus 10% of the stated value. For example, about 0.5 would include 0.45 and 0.55, about 10 would include 9 to 11, and about 1000 would include 900 to 1100.

[0079] As used herein, the term "coupling" and similar terms refer to the direct or indirect engagement of two components with each other. Such engagement can be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such engagement can be achieved by the two components, or two components and any additional intermediate components, being integrally formed into a single unit, or by the two components, or two components and any additional intermediate components, being attached to each other.

[0080] It is important to note that the structures and arrangements of the various exemplary embodiments are merely illustrative. While only a few embodiments have been described in detail in this disclosure, those skilled in the art will readily recognize that many modifications (e.g., variations in the size, dimensions, structure, shape and proportion of various elements, values ​​of parameters, mounting arrangements, use of materials, color, orientation, etc.) are possible without substantially departing from the novel teachings and advantages of the subject matter described herein. Furthermore, it should be understood that features from one embodiment disclosed herein can be combined with features from other embodiments disclosed herein, as will be understood by those skilled in the art. Other substitutions, modifications, variations, and omissions may also be made in the design, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of these embodiments.

[0081] While this specification contains numerous specific implementation details, these should not be construed as limiting any embodiment or the scope of the claims, but rather as descriptions of features characteristic of particular implementations of specific embodiments. Certain features described in the context of individual implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually in multiple implementations or in any suitable sub-combination. Furthermore, while features may be described above as functioning in certain combinations, and even initially claimed in this way, in some cases one or more features from the claimed combination may be removed from that combination, and the claimed combination may involve sub-combinations or variations thereof.

Claims

1. A post-processing system, comprising: A particulate filter configured to receive exhaust gas from an engine; and The controller executes computer-readable instructions stored in memory to: Based on the pressure measurements at both ends of the particulate filter, the actual pressure drop across the particulate filter is determined. Based on a first calibration table and a second calibration table, the expected total ash accumulation rate in the particulate filter is determined. The first calibration table includes multiple pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. The second calibration table includes multiple duty cycles and an estimated fuel consumption rate at each of the multiple duty cycles. Based on the expected total ash accumulation rate, the expected pressure drop across the particulate filter is determined; Compare the expected pressure drop with the actual pressure drop; Based on the comparison, it is determined whether the fuel consumption rate of the engine is abnormal; and In response to determining that the engine's fuel consumption rate is abnormal, an alarm is issued to indicate the abnormal fuel consumption rate.

2. The post-processing system according to claim 1, wherein, The second calibration table also includes an additional calibration table that includes a second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

3. The post-processing system according to claim 1, wherein, The controller executes the computer-readable instructions to determine that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and to determine that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

4. A post-processing method, comprising: The controller of the aftertreatment system determines the actual pressure drop across the particulate filter based on pressure measurements taken across the particulate filter, which is configured to receive exhaust gas from the engine. The controller determines the expected total ash accumulation rate in the particulate filter based on a first calibration table and a second calibration table. The first calibration table includes multiple pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. The second calibration table includes multiple duty cycles and an estimated fuel consumption rate at each of the multiple duty cycles. The controller determines the expected pressure drop across the particulate filter based on the expected total ash accumulation rate; The controller compares the expected voltage drop with the actual voltage drop. The controller determines whether the fuel consumption rate in the engine is abnormal based on the comparison. and In response to determining that the engine's fuel consumption rate is abnormal, the controller issues an alarm to indicate the abnormal fuel consumption rate.

5. The method according to claim 4, wherein, The second calibration table also includes an additional calibration table that includes a second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

6. The method of claim 4, further comprising the controller determining that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and determining that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

7. A non-transitory computer-readable medium comprising computer-readable instructions stored thereon, the computer-readable instructions, when executed by a controller of a post-processing system, causing the controller to perform a process comprising the following operations: The actual pressure drop across the particulate filter is determined based on pressure measurements taken across the particulate filter, which is configured to receive exhaust gas from the engine. Based on a first calibration table and a second calibration table, the expected total ash accumulation rate in the particulate filter is determined. The first calibration table includes multiple pressure drops across the test particulate filter and a corresponding first ash accumulation rate or soot and ash accumulation rate in the test particulate filter at each of the multiple pressure drops. The second calibration table includes multiple duty cycles and an estimated fuel consumption rate at each of the multiple duty cycles. Based on the expected total ash accumulation rate, the expected pressure drop across the particulate filter is determined; Compare the expected pressure drop with the actual pressure drop; Based on the comparison, it is determined whether the fuel consumption rate in the engine is abnormal; and In response to determining that the engine's fuel consumption rate is abnormal, an alarm is issued to indicate the abnormal fuel consumption rate.

8. The non-transitory computer-readable medium according to claim 7, wherein, The second calibration table also includes an additional calibration table that includes a second ash accumulation rate corresponding to the estimated fuel consumption rate at each of the plurality of duty cycles.

9. The non-transitory computer-readable medium according to claim 7, wherein, The controller also executes computer-readable instructions to determine that the fuel consumption rate in the engine is abnormal based on the actual pressure drop being greater than the expected pressure drop, and to determine that the fuel consumption rate in the engine is not abnormal based on the actual pressure drop being less than or equal to the expected pressure drop.

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