A DPF ash quality and source analysis method and system

Abstract

The present disclosure provides a method and system for analyzing the quality and source of DPF ash, and the scheme includes: S1: when a preset condition is met, obtaining the DPF ash content within the current window detection period; S2: calculating the ash content growth rate between the current window and the previous window detection period, and comparing it with the preset first threshold value to determine whether it exceeds the limit; S3: looping through steps S1 to S2, and counting the number of consecutive exceeding the limit. When the number of consecutive exceeding the limit is greater than the preset second threshold value, the loop is terminated and an ash content growth rate abnormality alarm is issued; S4: determining whether the value of the pressure sensor after the air filter element is higher than the preset third threshold value. If it is higher than the preset third threshold value, it is determined that the source of the ash content is an air filter element failure. If it is lower than the preset third threshold value, it is determined that the source of the ash content is an engine oil failure.

Description

Technical Field

[0001] The present invention belongs to the technical field of exhaust gas treatment, and in particular, relates to a method and system for analyzing the quality and source of DPF ash. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] The substances in the diesel engine aftertreatment device DPF (Diesel Particulate Filter) can be divided into two types: carbon (Soot) and ash (Ash). Soot is produced by engine combustion, and Ash is produced by the environment or the oil involved in combustion. The existence of Ash will also cause the DPF to produce a pressure difference; and the excessive accumulation of Ash can cause the DPF pressure difference to increase or even clog. Both of the above have a negative impact on the controller's accurate calculation, and even cause the DPF to fail.

[0004] The inventors found that diesel engine exhaust contains carbon particles, which need to be captured by DPF to reduce exhaust pollution. When the amount of carbon particles captured by DPF is too much, they will be removed by high-temperature combustion to achieve the purpose of DPF's cyclic capture of carbon particles. The key point of this scheme is the evaluation and calculation of the mass of carbon particles in DPF. If ash particles are mixed in this part of carbon particles, it will have a bad impact on the scheme of calculating the mass of carbon particles by pressure difference, and its calculation result cannot accurately reflect the amount of carbon particles in DPF. Thereby, the regeneration time is incorrectly extended or the regeneration temperature is incorrectly increased, resulting in damage to DPF or shortening its service life. The main sources of DPF ash can be divided into engine oil involved in combustion and unclean air entering the cylinder. Reasonable determination of the source of ash will provide users with a reliable reference for reasonable maintenance of equipment, directly extend the service life of equipment and reduce user costs. Summary of the invention

[0005] In order to solve the above problems, the present disclosure provides a DPF ash quality and source analysis method and system, the scheme determines whether the DPF ash growth rate is abnormal by determining whether the DPF ash growth rate increases continuously between calculation windows, and distinguishes whether the abnormally increased ash comes from an abnormal air filter or engine oil involved in combustion through a pressure sensor behind the air filter element, and reminds the driver whether a service station cleaning operation is required by the DPF ash content within the calculation window. The above design can effectively evaluate the ash content in the DPF, remind the driver to perform cleaning and maintenance operations, and avoid the problem of incorrect assessment of the carbon content in the DPF by the on-board system due to abnormal ash content growth or excessive ash content, and DPF damage due to excessive temperature or too long time when the carbon in the DPF is burned at high temperature.

[0006] According to a first aspect of an embodiment of the present disclosure, a method for analyzing DPF ash quality and source is provided, comprising:

[0007] S1: When the preset conditions are met, the DPF ash content within the current window detection period is obtained;

[0008] S2: Calculate the gray component growth rate between the current window and the previous window detection period, and compare it with the preset first threshold to determine whether it exceeds the limit;

[0009] S3: cyclically executing steps S1 to S2, and counting the number of consecutive exceeding the limit. When the number of consecutive exceeding the limit is greater than the preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued;

[0010] S4: Determine whether the value of the pressure sensor after the air filter is higher than a preset third threshold value. If it is higher than the preset third threshold value, determine that the source of the ash is an air filter failure. If it is lower than the preset third threshold value, determine that the source of the ash is an engine oil failure.

[0011] Furthermore, the DPF ash content within the current window detection period is obtained, specifically: when the parking regeneration is completed, the current detection window is triggered; based on the exhaust gas mass flow and DPF pressure difference value at this time, the mapping table of the engine bench calibration is queried to preliminarily determine the ash content at this time; and the final ash content is obtained after DPF temperature correction.

[0012] Furthermore, the preset condition is that the engine running time or running mileage meets a preset threshold.

[0013] Furthermore, the air filter failure includes damage to the air filter or the filtering function reaching an upper limit, and the engine oil failure includes abnormal engine oil consumption or engine oil participating in combustion in the cylinder.

[0014] Furthermore, when the obtained DPF ash content exceeds a preset fourth threshold, the driver cleans and maintains the DPF according to the ash source determined by the ash content.

[0015] According to a second aspect of an embodiment of the present disclosure, a DPF ash quality and source analysis system is provided, comprising:

[0016] An ash content calculation unit, which is used to obtain the DPF ash content within the current window detection period when a preset condition is met;

[0017] A growth rate over-limit judgment unit is used to calculate the growth rate of the gray content in the current window and the previous window detection period, and compare it with a preset first threshold value to determine whether it exceeds the limit;

[0018] An alarm unit is used to cyclically execute the steps in the ash content calculation unit and the growth rate over-limit judgment unit, and count the number of consecutive over-limit times. When the number of consecutive over-limit times is greater than a preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued;

[0019] The ash source judgment unit is used to judge whether the value of the pressure sensor after the air filter is higher than the preset third threshold value. If it is higher than the preset third threshold value, it is judged that the ash source is an air filter failure. If it is lower than the preset third threshold value, it is judged that the ash source is an engine oil failure.

[0020] Furthermore, the air filter rear pressure sensor is specifically arranged on the air intake pipe after the DPF air filter.

[0021] According to a third aspect of an embodiment of the present disclosure, there is provided an electronic device comprising a memory, a processor and a computer program stored and running on the memory, wherein when the processor executes the program, the method for analyzing the quality and source of DPF ash is implemented.

[0022] According to a fourth aspect of an embodiment of the present disclosure, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the method for analyzing the quality and source of DPF ash is implemented.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The present disclosure provides a method and system for analyzing the quality and source of DPF ash. The scheme determines whether the DPF ash growth rate is abnormal by determining whether the DPF ash growth rate is continuously increasing between calculation windows, and uses a pressure sensor behind the air filter to distinguish whether the abnormally increasing ash comes from an abnormal air filter or engine oil involved in combustion. The DPF ash content within the calculation window reminds the driver whether a service station cleaning operation is required. The above design can effectively evaluate the ash content in the DPF, remind the driver to perform cleaning and maintenance operations, and avoid the problem of the vehicle system's incorrect assessment of the carbon content in the DPF due to abnormal ash content growth or excessive ash content, and the DPF damage caused by excessive temperature or excessive time when the carbon in the DPF is burned at high temperature.

[0025] (2) The scheme disclosed in the present invention adds a pressure sensor behind the air filter element, and effectively determines the source of ash by judging the abnormal increase of pressure difference. Based on the obtained source of ash, the driver can accurately determine the parts to be maintained during the maintenance process, thereby improving the maintenance efficiency and accuracy.

[0026] Advantages of additional aspects of the present disclosure will be given in part in the following description and in part will become apparent from the following description or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure.

[0028] Figure 1 It is a flow chart of a DPF ash quality and source analysis method described in an embodiment of the present disclosure;

[0029] Figure 2 Schematic diagram of the installation position of the pressure sensor described in the embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0033] In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments may be combined with each other.

[0034] Terminology explanation:

[0035] DPF: Diesel Particulate Filter. A device installed in the exhaust system of a diesel vehicle to reduce particulate matter in the exhaust by filtering.

[0036] Embodiment 1:

[0037] The purpose of this embodiment is to provide a method for analyzing the quality and source of DPF ash.

[0038] A method for analyzing the quality and source of DPF ash, comprising:

[0039] S1: When the preset conditions are met, the DPF ash content within the current window detection period is obtained;

[0040] S2: Calculate the gray component growth rate between the current window and the previous window detection period, and compare it with the preset first threshold to determine whether it exceeds the limit;

[0041] S3: cyclically executing steps S1 to S2, and counting the number of consecutive exceeding the limit. When the number of consecutive exceeding the limit is greater than the preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued;

[0042] S4: Determine whether the value of the pressure sensor after the air filter is higher than a preset third threshold value. If it is higher than the preset third threshold value, determine that the source of the ash is an air filter failure. If it is lower than the preset third threshold value, determine that the source of the ash is an engine oil failure.

[0043] Furthermore, the DPF ash content within the current window detection period is obtained as follows: when the parking regeneration is completed, the current detection window is triggered; it is considered that the carbon particles in the DPF have been completely burned out at this time, and the particle mass obtained by the pressure difference scheme is all the ash particle mass (i.e., ash content). Among them, the pressure difference scheme is: by checking the corresponding mapping table (obtained by engine bench calibration) based on the exhaust gas mass flow rate and DPF pressure difference at this time, the ash particle mass at this time is preliminarily determined, and the final accurate DPF ash content is obtained after correction by DPF temperature (based on DPF temperature, checking the mapping table obtained by engine bench calibration).

[0044] Furthermore, the preset third threshold value is determined based on the ambient temperature and driving history, specifically: the intake mass flow rate is calculated from the exhaust mass flow rate and the fuel consumption, and the corresponding mapping table generated by the engine bench calibration is checked based on the intake mass flow rate to preliminarily obtain the threshold value; at the same time, considering that the pressure is affected by the ambient temperature and the working condition of the filter element is affected by the mileage, the obtained threshold value is corrected based on the influence of the two to obtain the third threshold value.

[0045] Furthermore, the preset condition is that the engine running time or running mileage meets a preset threshold.

[0046] Furthermore, the air filter failure includes damage to the air filter or the filtering function reaching an upper limit, and the engine oil failure includes abnormal engine oil consumption or engine oil participating in combustion in the cylinder.

[0047] Furthermore, when the obtained DPF ash content exceeds a preset fourth threshold, the driver cleans and maintains the DPF according to the ash source determined by the ash content.

[0048] Specifically, for ease of understanding, the solution disclosed in the present disclosure is described in detail below with reference to the accompanying drawings:

[0049] like Figure 1 As shown, the present disclosure proposes a DPF ash quality and source analysis method, which specifically includes the following steps:

[0050] Based on the on-board ECU, the engine running time or mileage is monitored in real time. When the preset running time (such as 300h) or mileage (24000Km) is reached, the detection window is entered.

[0051] Step 1: Calculate the DPF ash content within the current window calculation period, and calculate the DPF ash content growth rate between the ash content and the ash content in the last window calculator; and determine whether the ash content growth rate exceeds the limit based on the comparison result between the ash content growth rate and the preset first threshold value (generated by engine bench calibration); and determine whether the growth rate exceeds the limit continuously, that is, it exceeds the limit this time and the limit was also exceeded during the last detection, and so on.

[0052] Step 2: If the number of consecutive exceeding limits exceeds a preset second threshold value (generated by engine bench calibration, such as 3 times), an abnormal ash growth rate fault is reported.

[0053] Step three: According to whether the value of the pressure sensor after the air filter is higher than the preset third threshold, decide to report that the ash growth rate is abnormal due to the abnormal air filter or the ash growth rate is abnormal due to abnormal oil consumption. The preset third threshold is obtained by checking the ambient temperature, mileage, etc. Generally speaking, the ash in the DPF comes from unclean air or oil participating in the combustion in the cylinder; if the value of the pressure sensor after the air filter is higher than the threshold, it is considered that the air filter has lost its filtering function (is damaged), that is, the unclean air participates in the combustion because of the damaged air filter, which leads to excessive growth of the DPF ash. Otherwise, it is considered that the ash growth comes from abnormal oil consumption and participation in the combustion in the cylinder.

[0054] The preset third threshold is determined based on the ambient temperature and mileage through engine bench calibration.

[0055] Step 4: Based on whether the DPF ash content calculated in step 1 during the window calculation period exceeds the preset fourth threshold (calibrated by the engine test bench according to the DPF volume characteristics, such as 5g / L), decide whether to remind the driver that there is too much accumulated ash in the DPF and that he needs to go to the service station for cleaning.

[0056] The scheme disclosed in the present invention determines whether the DPF ash content growth rate is abnormal by determining whether the DPF ash content growth rate increases continuously between calculation windows, and distinguishes whether the abnormally increased ash content comes from an abnormal air filter or engine oil involved in combustion through a pressure sensor behind the air filter element, and reminds the driver whether a service station cleaning operation is required by the DPF ash content within the calculation window. The above design can effectively evaluate the ash content in the DPF, and remind the driver to perform cleaning and maintenance operations, thereby avoiding the problem of the vehicle-mounted system's incorrect assessment of the carbon content in the DPF due to abnormal ash content growth or excessive ash content, and the DPF being damaged due to excessive temperature or too long a time when the carbon in the DPF is burned at high temperature.

[0057] Embodiment 2:

[0058] The purpose of this embodiment is to provide a DPF ash quality and source analysis system, including:

[0059] An ash content calculation unit, which is used to obtain the DPF ash content within the current window detection period when a preset condition is met;

[0060] A growth rate over-limit judgment unit is used to calculate the growth rate of the gray content in the current window and the previous window detection period, and compare it with a preset first threshold value to determine whether it exceeds the limit;

[0061] An alarm unit is used to cyclically execute the steps in the ash content calculation unit and the growth rate over-limit judgment unit, and count the number of consecutive over-limit times. When the number of consecutive over-limit times is greater than a preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued;

[0062] The ash source judgment unit is used to judge whether the value of the pressure sensor after the air filter is higher than the preset third threshold value. If it is higher than the preset third threshold value, it is judged that the ash source is an air filter failure. If it is lower than the preset third threshold value, it is judged that the ash source is an engine oil failure.

[0063] Furthermore, the air filter rear pressure sensor is specifically arranged on the air intake pipe after the DPF air filter.

[0064] In further embodiments, there is also provided:

[0065] An electronic device includes a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the method described in Embodiment 1 is performed. For the sake of brevity, no further description is given here.

[0066] It should be understood that in this embodiment, the processor may be a central processing unit CPU, and the processor may also be other general-purpose processors, digital signal processors DSP, application-specific integrated circuits ASIC, off-the-shelf programmable gate arrays FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0067] The memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0068] A computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by a processor, the method described in embodiment 1 is completed.

[0069] The method in the first embodiment can be directly embodied as a hardware processor, or a combination of hardware and software modules in the processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.

[0070] Those skilled in the art will appreciate that the units, i.e., algorithm steps, of the various examples described in the present embodiment can be implemented in electronic hardware or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this disclosure.

[0071] The DPF ash quality and source analysis method and system provided in the above embodiment can be implemented and have broad application prospects.

[0072] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for analyzing the quality and source of DPF ash, characterized in that: include: S1: When the preset conditions are met, the DPF ash content within the current window detection period is obtained; S2: Calculate the gray component growth rate between the current window and the previous window detection period, and compare it with the preset first threshold to determine whether it exceeds the limit; S3: cyclically executing steps S1 to S2, and counting the number of consecutive exceeding the limit. When the number of consecutive exceeding the limit is greater than the preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued; S4: determining whether the value of the pressure sensor behind the air filter is higher than a preset third threshold value, if higher than the preset third threshold value, determining that the source of the ash is an air filter failure, if lower than the preset third threshold value, determining that the source of the ash is an engine oil failure; The method of obtaining the DPF ash content within the current window detection period is as follows: when the parking regeneration is completed, the current detection window is triggered; based on the exhaust gas mass flow rate and the DPF pressure difference value at this time, the mapping table of the engine bench calibration is queried to preliminarily determine the ash content at this time; The final ash content is obtained after DPF temperature correction.

2. A DPF ash quality and source analysis method according to claim 1, characterized in that: The preset condition is that the engine running time or running mileage meets a preset threshold.

3. A DPF ash quality and source analysis method according to claim 1, characterized in that: The air filter failure includes damage to the air filter or the filtering function reaching the upper limit, and the engine oil failure includes abnormal oil consumption or engine oil participating in the combustion in the cylinder.

4. A DPF ash quality and source analysis method according to claim 1, characterized in that: When the obtained DPF ash content exceeds a preset fourth threshold, the driver cleans and maintains the DPF according to the ash source determined by the ash content.

5. A DPF ash quality and source analysis system, characterized in that: include: An ash content calculation unit, which is used to obtain the DPF ash content within the current window detection period when a preset condition is met; A growth rate over-limit judgment unit is used to calculate the growth rate of the gray content in the current window and the previous window detection period, and compare it with a preset first threshold value to determine whether it exceeds the limit; An alarm unit is used to cyclically execute the steps in the ash content calculation unit and the growth rate over-limit judgment unit, and count the number of consecutive over-limit times. When the number of consecutive over-limit times is greater than a preset second threshold, the cycle is terminated and an ash content growth rate abnormality alarm is issued; An ash source determination unit, which is used to determine whether the value of the pressure sensor after the air filter is higher than a preset third threshold value, if it is higher than the preset third threshold value, it is determined that the ash source is an air filter failure, if it is lower than the preset third threshold value, it is determined that the ash source is an engine oil failure; The method of obtaining the DPF ash content within the current window detection period is as follows: when the parking regeneration is completed, the current detection window is triggered; based on the exhaust gas mass flow rate and the DPF pressure difference value at this time, the mapping table of the engine bench calibration is queried to preliminarily determine the ash content at this time; The final ash content is obtained after DPF temperature correction.

6. A DPF ash quality and source analysis system as claimed in claim 5, characterized in that: The air filter rear pressure sensor is specifically arranged on the DPF air filter rear air intake pipe.

7. A DPF ash quality and source analysis system as claimed in claim 5, characterized in that: The air filter failure includes damage to the air filter or the filtering function reaching the upper limit, and the engine oil failure includes abnormal oil consumption or engine oil participating in the combustion in the cylinder.

8. An electronic device comprising a memory, a processor and a computer program stored and running on the memory, characterized in that: When the processor executes the program, a DPF ash quality and source analysis method as described in any one of claims 1 to 4 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a DPF ash quality and source analysis method as described in any one of claims 1 to 4 is implemented.

Images