Diesel engine DPF carbon loading capacity correction method, device and system

Abstract

The invention discloses a diesel engine DPF carbon load correction method, device and system. The diesel engine DPF carbon load correction method comprises the following steps that the upstream exhaust temperature, the atmospheric pressure value and the corresponding running speed of a DPF are obtained; according to the upstream exhaust temperature and the atmospheric pressure value of the DPF, a correction coefficient is determined in a table MAP look-up mode, and the corresponding relation of the upstream exhaust temperature and the atmospheric pressure value of the DPF and the correction coefficient is recorded in the table MAP; multiplying the correction coefficient by the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; and according to the driving speed, the driving mileage is determined, and integration is carried out on the corrected carbon model growth rate within the driving mileage range to obtain the DPF carbon loading amount corresponding to the driving mileage. The DPF internal carbon model is corrected and calculated according to the current DPF upstream temperature and the current atmospheric pressure of the diesel engine, the accuracy of carbon load calculation is improved, and engine emission and oil consumption are both considered.

Description

Technical Field

[0001] The present invention belongs to the technical field of DPF carbon load calculation methods, and in particular relates to a diesel engine DPF carbon load correction method, device and system. Background Art

[0002] With the implementation of the China VI emission regulations, commercial vehicle diesel engine systems all use Diesel Particulate Filters (DPFs) to treat engine exhaust particulate matter emissions, ensuring that PM and other particulate matter emissions meet the requirements of the China VI regulations. When the particulate filter becomes saturated with trapped particles, it needs to be regenerated. This requires precise calculation of the particulate filter capacity and engine carbon particulate matter emissions to effectively protect the catalyst and reduce fuel consumption. Specifically, when the carbon load in the DPF is too high, there is a risk of burning the DPF during regeneration. When the carbon load in the DPF is too low or the mileage since the last regeneration is short, regeneration is triggered, resulting in high fuel consumption for the entire vehicle.

[0003] China VI electronically controlled diesel engines are equipped with differential pressure sensors at both ends of the particulate filter. These sensors monitor the internal resistance of the DPF substrate in real time and, based on this resistance, calculate the current carbon load within the particulate filter. The mainstream particulate filter substrates on the market are made of silicon carbide and cordierite. The silicon carbide substrate has greater internal resistance, resulting in greater differential pressure discrimination and better identification of the carbon load within the substrate. Cordierite, on the other hand, has lower internal resistance and less distinct differential pressure, making it difficult for differential pressure sensors to accurately identify the carbon load within the substrate, hindering effective protection of the particulate filter and presenting limitations. Summary of the Invention

[0004] In order to solve the problem that the existing method based on the pressure difference sensor cannot well identify the carbon load in the carrier, the present invention provides a diesel engine DPF carbon load correction method, device and system.

[0005] The purpose of the present invention is achieved through the following technical solutions: A first aspect of the present invention discloses a method for correcting carbon load of a diesel engine DPF, comprising the following steps: Obtain the exhaust temperature, atmospheric pressure and corresponding driving speed upstream of the DPF; Determine the correction coefficient by looking up a table MAP according to the DPF upstream exhaust temperature and atmospheric pressure value, wherein the table MAP records the corresponding relationship between the DPF upstream exhaust temperature, atmospheric pressure value and the correction coefficient; Multiplying the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; The mileage is determined according to the driving speed, and the DPF carbon load corresponding to the mileage is obtained by integrating the corrected carbon model growth rate within the mileage range.

[0006] The second aspect of the present invention discloses a diesel engine DPF carbon load correction device, comprising a memory and a controller that are communicatively connected in sequence, wherein the memory stores a computer program, and the controller is used to read the computer program and execute the diesel engine DPF carbon load correction method described in the first aspect.

[0007] A third aspect of the present invention discloses a diesel engine DPF carbon load correction device, comprising: A data acquisition unit, the data acquisition unit is used to obtain the exhaust temperature, atmospheric pressure value and corresponding driving speed upstream of the DPF; A lookup unit, configured to determine a correction coefficient by looking up a table (MAP) according to the exhaust gas temperature and atmospheric pressure values ​​upstream of the DPF; a calculation unit configured to multiply the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; An integration unit is used to determine the mileage according to the driving speed, and integrate the corrected carbon model growth rate within the mileage range to obtain the DPF carbon load corresponding to the mileage.

[0008] A fourth aspect of the present invention discloses a diesel engine DPF carbon load correction system, comprising: A temperature sensor for collecting exhaust gas temperature upstream of the DPF; A pressure sensor for collecting atmospheric pressure values; A speed sensor for collecting vehicle speed; In the diesel engine DPF carbon load correction device described in the second or third aspect, the temperature sensor, pressure sensor and speed sensor are signal-connected to the diesel engine DPF carbon load correction device.

[0009] Compared with the prior art, the present invention has at least the following advantages and beneficial effects: The present invention corrects and calculates the DPF internal carbon model according to the current DPF upstream temperature and current atmospheric pressure of the diesel engine, thereby improving the accuracy of carbon load calculation and taking into account engine emissions and fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 Flowchart of the method of the present invention. DETAILED DESCRIPTION

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0013] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0014] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0015] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0016] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use, or are the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended only to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0017] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0018] The particulate filter (DPF) carrier is made of chlorite material, and the differential pressure sensor cannot accurately identify the current carbon load in the carrier, which easily leads to the problem of overload of carbon load in the DPF, causing the carrier to burn during regeneration. The carbon particle emissions of diesel engines are closely related to the altitude and the internal temperature of the DPF carrier. At high altitudes, the oxygen content is thin, and the carbon particle emissions of diesel engines are greater than those at low altitudes; the engine exhaust temperature is high, the passive regeneration of soot particles is strong, and the carbon particles in the DPF carrier grow slowly. In this regard, the first aspect of the present invention discloses a method for correcting the carbon load of a diesel engine DPF, specifically, as follows: Figure 1 As shown, the present invention includes steps S1 to S4.

[0019] Step S1: Obtain the exhaust gas temperature, atmospheric pressure value and corresponding driving speed upstream of the DPF.

[0020] Step S2: determining a correction coefficient by looking up a table MAP according to the DPF upstream exhaust temperature and the atmospheric pressure value, wherein the table MAP records the corresponding relationship between the DPF upstream exhaust temperature, the atmospheric pressure value and the correction coefficient.

[0021] Specifically, since the exhaust gas temperature and atmospheric pressure upstream of the DPF have a large range, in order to reduce the storage capacity, the exhaust gas temperature upstream of the DPF in Table MAP is 100*N1°C, and the atmospheric pressure value is 100*N2 hPa, where N1 is a natural number from 0 to 6, and N2 is a natural number from 5 to 12, as shown in Table 1 below.

[0022] Table 1 When the exhaust gas temperature and / or atmospheric pressure upstream of the DPF are not integers, they can be calculated according to the above table.

[0023] Assuming that the exhaust temperature upstream of the DPF is greater than 100*N1°C and less than 100*(N1+1)°C and / or the atmospheric pressure is greater than 100*N2 hPa and less than 100*(N2+1) hPa, the specific calculation process of the correction coefficient F is as follows: F1=(1-(P-100*N2) / 100)*f1+(P-100*N2) / 100*f2 F2=(1-(P-100*N2) / 100)*f3+(P-100*N2) / 100*f4 F=(1-(T-100*N1) / 100)* F1+(T-100*N1) / 100*F2, Where P is the atmospheric pressure, T is the exhaust temperature upstream of the DPF, f1 is the correction factor for an exhaust temperature upstream of 100*N1°C and an atmospheric pressure of 100*N2 hPa, f2 is the correction factor for an exhaust temperature upstream of 100*N1°C and an atmospheric pressure of 100*(N2+1) hPa, f3 is the correction factor for an exhaust temperature upstream of 100*(N1+1)°C and an atmospheric pressure of 100*N2 hPa, f4 is the correction factor for an exhaust temperature upstream of 100*(N1+1)°C and an atmospheric pressure of 100*(N2+1) hPa, and F is the correction factor for an exhaust temperature upstream of the DPF greater than 100*N1°C and less than 100*(N1+1)°C and / or an atmospheric pressure greater than 100*N2 hPa and less than 100*(N2+1) hPa.

[0024] For example, assuming that the atmospheric pressure is 730 hPa and the exhaust temperature upstream of the DPF is 540° C.: at this time, F1= (1-30 / 100)*0.9+30 / 100*0.8=0.87 F2= (1-30 / 100)*0.8+30 / 100x0.8=0.8 F= (1-40 / 100)*0.87+40 / 100*0.8=0.842.

[0025] Step S3: multiplying the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate.

[0026] Step S4: Determine the mileage according to the driving speed, and integrate the corrected carbon model growth rate within the mileage range to obtain the DPF carbon load corresponding to the mileage.

[0027] By using the above method, the DPF internal carbon model is corrected and calculated according to the current DPF upstream temperature and current atmospheric pressure of the diesel engine. This can not only improve the accuracy of carbon load calculation, but also achieve the purpose of protecting the particulate filter while taking into account engine emissions and fuel consumption.

[0028] The above method can achieve a low carbon model growth rate at high exhaust temperatures and a correspondingly high carbon model growth rate at high altitudes. This means that if the engine frequently operates at high exhaust temperatures, the DPF regeneration interval will be longer. Conversely, if the engine frequently operates at high altitudes, the DPF regeneration interval can be appropriately shortened, ultimately achieving the goal of protecting the DPF while reducing vehicle fuel consumption.

[0029] For example, for a certain model of running diesel engine, when the exhaust temperature T upstream of the DPF is greater than 500°C and the atmospheric pressure P is greater than 90kPa, the carbon model rate correction coefficient is less than 0.9, that is, the carbon model growth rate is slow, the calculated regeneration interval mileage is longer, the vehicle fuel consumption is optimal, and the focus is on reducing vehicle fuel consumption.

[0030] When the exhaust temperature T upstream of the DPF is less than 400°C and the atmospheric pressure is greater than 80kPa, the DPF passive regeneration is weak or there is no passive regeneration. At this time, the carbon model rate correction coefficient is 1, that is, the carbon model growth rate is moderate.

[0031] When the exhaust temperature T upstream of the DPF is less than 400°C and the atmospheric pressure is less than 80kpa, the vehicle is operating at a high altitude, and the DPF passive regeneration is weak or there is no passive regeneration; at the same time, because the air is thin and the oxygen content is low at high altitudes, the actual carbon in the DPF tends to grow faster. At this time, the carbon model rate correction coefficient is greater than 1, that is, the carbon model growth rate is accelerated, and the regeneration interval mileage after calculation will be shortened to avoid damage to the DPF caused by actual carbon overload, and focus on protecting the DPF.

[0032] A second aspect of the present invention discloses a diesel engine DPF carbon load correction device, comprising a memory and a controller in communication with each other. The memory stores a computer program, and the controller is configured to read the computer program and execute the diesel engine DPF carbon load correction method described in the first aspect. Specifically, the memory may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), flash memory, first-input first-output (FIFO), or first-input last-output (FILO) memory, among others. The controller may be, but is not limited to, a microcontroller from the STM32F105 series. Furthermore, the computer device may include, but is not limited to, a power supply unit, a display screen, and other necessary components.

[0033] A third aspect of the present invention discloses a diesel engine DPF carbon load correction device, comprising: A data acquisition unit, the data acquisition unit is used to obtain the exhaust temperature, atmospheric pressure value and corresponding driving speed upstream of the DPF; A lookup unit, configured to determine a correction coefficient by looking up a table (MAP) according to the exhaust gas temperature and atmospheric pressure values ​​upstream of the DPF; a calculation unit configured to multiply the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; An integration unit is used to determine the mileage according to the driving speed, and integrate the corrected carbon model growth rate within the mileage range to obtain the DPF carbon load corresponding to the mileage.

[0034] A fourth aspect of the present invention discloses a diesel engine DPF carbon load correction system, comprising: A temperature sensor for collecting exhaust gas temperature upstream of the DPF; A pressure sensor for collecting atmospheric pressure values; A speed sensor for collecting vehicle speed; In the diesel engine DPF carbon load correction device described in the second or third aspect, the temperature sensor, pressure sensor and speed sensor are signal-connected to the diesel engine DPF carbon load correction device.

[0035] The operating principles of the devices and systems disclosed in the second, third and fourth aspects of the present invention are the same as those of the first aspect and will not be described in detail here.

[0036] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for correcting carbon load of a diesel engine DPF, characterized in that: The following steps are involved: Obtain the exhaust temperature, atmospheric pressure and corresponding driving speed upstream of the DPF; Determine the correction coefficient by looking up a table MAP according to the DPF upstream exhaust temperature and atmospheric pressure value, wherein the table MAP records the corresponding relationship between the DPF upstream exhaust temperature, atmospheric pressure value and the correction coefficient; Multiplying the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; The mileage is determined according to the driving speed, and the DPF carbon load corresponding to the mileage is obtained by integrating the corrected carbon model growth rate within the mileage range.

2. A diesel engine DPF carbon load correction method according to claim 1, characterized in that: The exhaust gas temperature upstream of the DPF in the table MAP is 100*N1°C, the atmospheric pressure is 100*N2 hPa, N1 is a natural number from 0 to 6, and N2 is a natural number from 5 to 12; When the exhaust gas temperature upstream of the DPF is greater than 100*N1°C and less than 100*(N1+1)°C and / or the atmospheric pressure is greater than 100*N2hPa and less than 100*(N2+1)hPa, the correction coefficient is determined by looking up the MAP table according to the exhaust gas temperature upstream of the DPF and the atmospheric pressure as follows: F1=(1-(P-100*N2) / 100)*f1+(P-100*N2) / 100*f2 F2=(1-(P-100*N2) / 100)*f3+(P-100*N2) / 100*f4 F=(1-(T-100*N1) / 100)* F1+(T-100*N1) / 100*F2, Wherein, P is the atmospheric pressure value, T is the exhaust gas temperature upstream of the DPF, f1 is the correction coefficient corresponding to the exhaust gas temperature upstream of the DPF of 100*N1°C and the atmospheric pressure of 100*N2 hPa, f2 is the correction coefficient corresponding to the exhaust gas temperature upstream of the DPF of 100*N1°C and the atmospheric pressure of 100*(N2+1) hPa, f3 is the correction coefficient corresponding to the exhaust gas temperature upstream of the DPF of 100*(N1+1)°C and the atmospheric pressure of 100*N2 hPa, f4 is the correction coefficient corresponding to the exhaust gas temperature upstream of the DPF of 100*(N1+1)°C and the atmospheric pressure of 100*(N2+1) hPa, and F is the correction coefficient when the exhaust gas temperature upstream of the DPF is greater than 100*N1°C and less than 100*(N1+1)°C and / or the atmospheric pressure is greater than 100*N2 hPa and less than 100*(N2+1) hPa.

3. A diesel engine DPF carbon load correction device, comprising a memory and a controller in communication with each other, wherein the memory stores a computer program, characterized in that: The controller is used to read the computer program and execute the diesel engine DPF carbon load correction method according to any one of claims 1-2.

4. A diesel engine DPF carbon load correction device, characterized in that: include: A data acquisition unit, the data acquisition unit is used to obtain the exhaust temperature, atmospheric pressure value and corresponding driving speed upstream of the DPF; A lookup unit, configured to determine a correction coefficient by looking up a table (MAP) according to the exhaust gas temperature and atmospheric pressure values ​​upstream of the DPF; a calculation unit configured to multiply the correction coefficient and the DPF basic mileage carbon model growth rate to obtain a corrected carbon model growth rate; An integration unit is used to determine the mileage according to the driving speed, and integrate the corrected carbon model growth rate within the mileage range to obtain the DPF carbon load corresponding to the mileage.

5. A diesel engine DPF carbon load correction system, characterized in that: include: A temperature sensor for collecting exhaust gas temperature upstream of the DPF; A pressure sensor for collecting atmospheric pressure values; A speed sensor for collecting vehicle speed; A diesel engine DPF carbon load correction device according to claim 3 or 4, wherein the temperature sensor, pressure sensor and speed sensor are signal-connected to the diesel engine DPF carbon load correction device.

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