Doc test method for virtual calibration post-processing model development
By simplifying the DOC testing method, the problem of long development time for virtual calibration post-processing models is solved, achieving efficient model development and cost savings while ensuring model accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI YUCHAI MASCH CO LTD
- Filing Date
- 2026-02-28
- Publication Date
- 2026-05-29
AI Technical Summary
Existing DOC experiments are time-consuming in the development of virtual calibration post-processing models, occupy bench resources, and affect product development progress.
A simplified DOC testing method is adopted, including specific sensor arrangement and test procedures, to shorten the test time. DOC, DPF, SCRⅠ and SCRⅡ-ASC tests are conducted through a DOC test device. Combined with load step, WHSC, DOC ignition and WHTC tests, thermocouple arrangement is optimized to reduce the use of sensors.
While maintaining model accuracy, the test time is shortened to 30 hours, the model accuracy differs from the complete test data by ≤5%, sensor costs are saved, and the selection of post-processing components and engine development are supported.
Smart Images
Figure CN122108607A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of diesel engine technology, and more specifically, particularly to a DOC test method for the development of virtual calibration post-processing models. Background Technology
[0002] Virtual calibration technology is an engine control strategy optimization method based on engine simulation models and hardware-in-the-loop (HIL / SIL) platforms. Its core is to use digital means to replace or assist traditional bench calibration and vehicle calibration, achieving efficient and accurate matching of engine control parameters. Using virtual calibration technology requires developing a coupled model of the engine and aftertreatment system. Since this model is semi-physical and semi-empirical, its development requires calibration using actual experimental data. For the development of aftertreatment virtual calibration models, the current aftertreatment test acquisition time is approximately 240 hours, with DOC testing requiring about 80 hours. With limited bench resources, the long virtual calibration data acquisition test cycle encroaches on bench time for other product development work, hindering product development progress. Therefore, to shorten the test time, in recent years, we have made several attempts and optimizations to the DOC test data acquisition method, ultimately simplifying the test method while maintaining model accuracy. This simplified method can reduce the time to 30 hours, laying a solid foundation for accelerating product development.
[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0004] The purpose of this invention is to provide a DOC test method for the development of virtual calibration post-processing models. The data obtained by using this method can ensure the accuracy of the post-processing model of the virtual development platform, while reducing the need for sensors and other equipment, saving test time, and accelerating the model development of the virtual platform.
[0005] To achieve the above objectives, this invention provides a DOC testing method for developing a virtual calibration post-treatment model. The method utilizes a DOC testing device for virtual calibration post-treatment model development. The DOC testing device includes a DOC, DPF, mixing section, SCRⅠ, and SCRⅡ-ASC arranged sequentially along the exhaust gas flow direction; a first test module, a second test module, and multiple thermocouples. The first test module is positioned upstream of the DOC and SCRⅡ-ASC; the second test module is positioned downstream of the DOC, DPF, mixing section, and SCRⅡ-ASC; and multiple thermocouples are positioned inside the DOC, DPF, SCRⅠ, and SCRⅡ-ASC. The DOC testing method includes: sensor placement, including the arrangement of the first test module, the second test module, and multiple thermocouples; a DOC load step test; a WHSC test; a DOC ignition test; and a WHTC test.
[0006] In a preferred embodiment, the plurality of thermocouples includes three disposed inside the DOC, three inside the DPF, two inside the SCRⅠ, and four inside the SCRⅡ-ASC.
[0007] In a preferred embodiment, the three thermocouples disposed inside the DOC and the three thermocouples disposed inside the DPF are respectively disposed at both ends and the middle of the DOC and DPF. The thermocouples at both ends are 20 mm away from the edge of the end, and the thermocouple in the middle is located in the middle position between the thermocouples at both ends.
[0008] In a preferred embodiment, one of the two thermocouples located inside SCRⅠ is located at the front end, 20 mm from the edge, and the other is located in the middle.
[0009] In a preferred embodiment, the SCRⅡ-ASC is an integral structure, with one of the four thermocouples located inside the SCRⅡ-ASC located inside the SCRⅡ and 20mm from the rear edge, and the other three located at the front end, rear end and middle of the ASC respectively.
[0010] In a preferred embodiment, the first test module includes a first temperature measuring point, a first pressure measuring point, a first direct sampling measuring point, and a first NH3 measuring point; the second test module includes a second temperature measuring point, a second pressure measuring point, a carrier temperature measuring point, a second direct sampling measuring point, and a second NH3 measuring point.
[0011] In a preferred embodiment, the DOC load step test is a steady-state load change test. This test is used to calibrate the steady-state temperature and pressure drop of the model. The load in the DOC load step test needs to be changed for a certain period of time. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0012] In a preferred embodiment, the WHSC test consists of two consecutive WHSC tests at different initial temperatures. The WHSC test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0013] In a preferred embodiment, the DOC ignition test is a transient load change test. This test is used to calibrate the transient temperature, pressure drop and gas composition changes of the model. The DOC ignition test requires a fixed speed and a slow rise from one temperature to another. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature and carbon load meet certain requirements.
[0014] In a preferred embodiment, the WHTC test is a WHTC test conducted twice at different initial temperatures. This test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0015] Compared with existing technologies, the DOC test method for virtual calibration post-processing model development of the present invention has the following beneficial effects: The above-mentioned tests, sensor arrangements, test condition changes, and initial test condition control requirements are all necessary tests to ensure the accuracy of the post-processing model of the virtual development platform, taking approximately 30 hours. The accuracy of the DOC model obtained through the data acquired by this simplified DOC test method for virtual calibration post-processing model development is ≤5% different from the accuracy obtained using 80 hours of complete test data, which can be considered as essentially maintaining the same accuracy. The DOC test method proposed in this invention has fewer test items, which can shorten the model development cycle and enable the model to be used to guide the selection of post-processing components and the development of the entire engine. The DOC test method proposed in this invention reduces the number of sensors used by designing the thermocouple placement, and the model obtained based on this data is not significantly different from the model obtained from the complete data, saving test costs. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the experimental steps of the DOC test method according to an embodiment of the present invention;
[0017] Figure 2 This is a schematic diagram of the thermocouple arrangement according to an embodiment of the present invention;
[0018] Figure 3 This is a schematic diagram of the arrangement of test components and test modules according to an embodiment of the present invention;
[0019] Figure 4 This is a speed-torque curve diagram of a load step test according to an embodiment of the present invention.
[0020] Figure 5 This is a data curve diagram of an ignition experiment according to an embodiment of the present invention;
[0021] Figure 6 This is a data curve diagram of a WHSC experiment according to an embodiment of the present invention;
[0022] Figures 7a to 7b This is a data curve diagram of a WHTC experiment according to an embodiment of the present invention.
[0023] Explanation of key figure labels:
[0024] 1-DOC, 2-DPF, 3-Mixing section, 4-SCRⅠ, 5-SCRⅡ-ASC, 6-First test module, 61-First temperature measuring point, 62-First pressure measuring point, 63-First direct sampling measuring point, 64-First NH3 measuring point, 7-Second test module, 71-Second temperature measuring point, 72-Second pressure measuring point, 73-Carrier temperature measuring point, 74-Second direct sampling measuring point, 75-Second NH3 measuring point, 8-Urea nozzle, 9-Flange, 10-Thermocouple. Detailed Implementation
[0025] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0026] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0027] like Figures 1 to 3 As shown, according to a preferred embodiment of the present invention, a DOC test method for developing a virtual calibration post-treatment model is used. The DOC test method is conducted through a DOC test device for developing a virtual calibration post-treatment model. The DOC test device includes DOC1, DPF2, mixing section 3, SCRⅠ4, and SCRⅡ-ASC5 arranged sequentially along the exhaust gas flow direction; a first test module 6, a second test module 7, and multiple thermocouples 10; the first test module 6 is respectively located upstream of DOC1 and SCRⅡ-ASC5; the second test module 7 is respectively located downstream of DOC1, DPF2, mixing section 3, and SCRⅡ-ASC5; and multiple thermocouples 10 are respectively located inside DOC1, DPF2, SCRⅠ4, and SCRⅡ-ASC5. The DOC1 test method includes: sensor position arrangement, including the arrangement of the first test module 6, the second test module 7, and multiple thermocouples 10; DOC1 load step test; WHSC test; DOC1 ignition test; and WHTC test.
[0028] Please see Figure 2 and Figure 3 In some embodiments, DOC1, DPF2, mixing section 3 and SCRⅠ4 are connected by flange 9, and a urea nozzle 8 is provided on the mixing section 3 for spraying urea into the mixing section 3.
[0029] Please see Figure 2 In some embodiments, the plurality of thermocouples 10 includes three disposed inside DOC1, three disposed inside DPF2, two disposed inside SCRⅠ4, and four disposed inside SCRⅡ-ASC5.
[0030] In some embodiments, the three thermocouples 10 inside DOC1 and the three thermocouples 10 inside DPF2 are respectively located at both ends and the middle of DOC1 and DPF2. The thermocouples 10 located at both ends are 20 mm from the end edge, and the thermocouple 10 located in the middle is located in the middle of the thermocouples 10 at both ends.
[0031] In some embodiments, one of the two thermocouples 10 located inside SCRⅠ4 is located at the front end, 20 mm from the edge, and the other is located in the middle.
[0032] In some embodiments, SCRⅡ-ASC5 is an integral structure, with one of the four thermocouples 10 located inside SCRⅡ-ASC5 located inside SCRⅡ and 20mm from the rear edge, and the other three located at the front end, rear end and middle of ASC respectively.
[0033] Please see Figure 3 In some embodiments, the first test module 6 includes a first temperature measuring point 61, a first pressure measuring point 62, a first direct sampling measuring point 63, and a first NH3 measuring point 64; the second test module 7 includes a second temperature measuring point 71, a second pressure measuring point 72, a carrier temperature measuring point 73, a second direct sampling measuring point 74, and a second NH3 measuring point 75.
[0034] In some implementation methods, please refer to Table 1 for pre-experimental precautions for the DOC test method:
[0035] Table 1
[0036]
[0037] In some implementations, the DOC load step test is a steady-state load change test. This test is used to calibrate the steady-state temperature and pressure drop of the model. The load in the DOC load step test needs to be changed for a certain period of time. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0038] like Figure 4 As shown in Table 2:
[0039] Table 2
[0040]
[0041] In some implementations, the WHSC test consists of two consecutive WHSC tests at different initial temperatures. The WHSC test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0042] like Figure 5 As shown in Table 3:
[0043] Table 3
[0044]
[0045] In some implementations, the DOC ignition test is a transient load change test. This test is used to calibrate the transient temperature, pressure drop, and gas composition changes of the model. The DOC ignition test requires a fixed speed and a slow rise from one temperature to another. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0046] like Figure 6 As shown in Table 4:
[0047] Table 4
[0048]
[0049] In some implementations, the WHTC test is a WHTC test conducted twice at different initial temperatures. This test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
[0050] like Figures 7a to 7b As shown in Table 5:
[0051] Table 5
[0052]
[0053] In summary, the DOC test method for virtual calibration post-processing model development of the present invention has the following beneficial effects: The tests, sensor arrangements, test condition changes, and initial test condition control requirements conducted above are all necessary tests to ensure the accuracy of the post-processing model on the virtual development platform, taking approximately 30 hours. The accuracy of the DOC model obtained through this simplified DOC test method for virtual calibration post-processing model development deviates by ≤5% from the accuracy obtained using 80 hours of complete test data, which can be considered as essentially maintaining the same accuracy. The DOC test method proposed in this invention has fewer test items, which can shorten the model development cycle, allowing the model to be used to guide the selection of post-processing components and the development of the entire engine. The DOC test method proposed in this invention reduces the number of sensors used by designing thermocouple placement, and the model obtained based on this data is not significantly different from the model obtained with complete data, saving test costs.
[0054] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.
Claims
1. A DOC testing method for developing virtual calibration post-processing models, wherein experiments are conducted using a DOC testing apparatus for developing virtual calibration post-processing models, characterized in that, The DOC testing apparatus includes: DOC, DPF, mixing section, SCRⅠ and SCRⅡ-ASC are arranged sequentially along the direction of exhaust gas flow. The first test module is located upstream of the DOC and the SCRⅡ-ASC, respectively; The second test module is respectively located downstream of the DOC, the DPF, the mixing section, and the SCRⅡ-ASC; and Multiple thermocouples are respectively disposed inside the DOC, the DPF, the SCRⅠ, and the SCRⅡ-ASC; The DOC test method includes: The sensor placement includes the arrangement of the first test module, the second test module, and the plurality of thermocouples. DOC load step test; WHSC test; DOC ignition test; and WHTC trial.
2. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The plurality of thermocouples includes three located inside the DOC, three inside the DPF, two inside the SCRⅠ, and four inside the SCRⅡ-ASC.
3. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 2, characterized in that, The three thermocouples inside the DOC and the three thermocouples inside the DPF are respectively located at both ends and the middle of the DOC and the DPF. The thermocouples at both ends are 20mm from the edge of the end, and the thermocouple in the middle is located in the middle position between the thermocouples at both ends.
4. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 2, characterized in that, The two thermocouples located inside the SCRⅠ are located at the front end, 20 mm from the edge, and the other is located in the middle.
5. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 2, characterized in that, The SCRⅡ-ASC is an integral structure. There are four thermocouples inside the SCRⅡ-ASC. One of them is located inside the SCRⅡ and 20mm from the rear edge. The other three are located at the front end, rear end and middle of the ASC, respectively.
6. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The first test module includes a first temperature measuring point, a first pressure measuring point, a first direct sampling measuring point, and a first NH3 measuring point; the second test module includes a second temperature measuring point, a second pressure measuring point, a carrier temperature measuring point, a second direct sampling measuring point, and a second NH3 measuring point.
7. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The DOC load step test is a steady-state load change test. This test is used to calibrate the steady-state temperature and pressure drop of the model. The load in the DOC load step test needs to be changed for a certain period of time. Before the test starts, it is also necessary to ensure that the engine's operating mode, initial temperature and carbon load meet certain requirements.
8. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The WHSC test consists of two consecutive WHSC tests at different initial temperatures. The WHSC test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.
9. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The DOC ignition test is a transient load change test. This test is used to calibrate the transient temperature, pressure drop and gas composition changes of the model. The DOC ignition test requires a fixed speed and a slow rise from one temperature to another. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature and carbon load meet certain requirements.
10. The DOC experimental method for developing a virtual calibration post-processing model as described in claim 1, characterized in that, The WHTC test consists of two consecutive WHTC tests at different initial temperatures. This test is used to verify the steady-state temperature and pressure of the model. Before the test begins, it is also necessary to ensure that the engine's operating mode, initial temperature, and carbon load meet certain requirements.