Diesel engine regeneration cycle control method and device

Abstract

The invention relates to a diesel engine regeneration cycle control method and device, and the method comprises the steps: respectively obtaining regeneration mileage target values corresponding to different rotating speeds under the no-load and full-load states of an engine, and taking the regeneration mileage target values as reference values of a regeneration cycle; correction based on the vehicle speed and correction based on the exhaust temperature are conducted on the reference value of the regeneration cycle in sequence, and correction coefficients of the corresponding regeneration cycles under different working conditions of the engine are determined; according to the correction coefficients corresponding to the various working conditions, the regeneration cycle under the corresponding working conditions is determined, and the sum of the regeneration cycles under all the working conditions is the final regeneration cycle. According to the method, the carbon deposition mileage of the engine in the no-load state and the full-load state is used as the reference value of the regeneration cycle, and then the reference regeneration cycle is subjected to correction based on the rotating speed and correction based on the exhaust temperature, so that the obtained regeneration cycle fits the actual working condition, and the problem of frequent regeneration is relieved.

Description

Technical Field

[0001] The invention relates to the technical field of engine control, and in particular to a diesel engine regeneration period control method and device. Background Art

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

[0003] The DPF (particle collector) of a diesel engine is used to collect carbon particles in the exhaust gas. When the carbon particles accumulate to a certain extent, regeneration is required. Regeneration is divided into three stages: passive regeneration, active regeneration, and service regeneration. When the engine exhaust temperature is above 250°C, the NO2 in the exhaust and the soot react chemically to eliminate the carbon particles. This is passive regeneration. Active regeneration is used to increase the temperature in the exhaust treatment system and achieve soot combustion to eliminate carbon deposits in the DPF. Service regeneration is the regeneration during the disassembly and maintenance of the DPF during the engine shutdown maintenance phase.

[0004] Some engines running in specific environments need to determine the active regeneration cycle according to the operating conditions, and most of the engine's operating conditions are in the low-speed area. The active regeneration cycle determined based on the low-speed area is too short, which is prone to frequent regeneration problems. For example, the engine in a garbage truck, because the garbage truck needs to stop frequently to recycle the garbage bin, most of the operating conditions are in the low-speed area, and the existing technology for active regeneration is usually calibrated for common operating conditions, that is, low-speed areas. If the engine is running well, it is easy to cause the calibration cycle to be too short. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a diesel engine regeneration cycle control method and device, which respectively conducts a preliminary investigation on the carbon deposition mileage of the engine under no-load and full-load conditions, determines the regeneration mileage target values ​​corresponding to different vehicle speeds, and uses them as the reference values ​​of the regeneration cycle. The reference regeneration cycle is then corrected based on the vehicle speed and the exhaust temperature, and the correction coefficients corresponding to different engine operating conditions are determined. The sum of the regeneration cycles corresponding to multiple operating conditions is used as the final regeneration cycle.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a diesel engine regeneration cycle control method, comprising the following steps:

[0008] Obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load conditions respectively, and use them as the reference values ​​of the regeneration cycle;

[0009] The reference value of the regeneration cycle is corrected based on the vehicle speed and based on the exhaust temperature in sequence, and a correction coefficient of the regeneration cycle corresponding to different engine operating conditions is determined;

[0010] The correction coefficients corresponding to various working conditions are used to determine the regeneration period under the corresponding working conditions. The sum of the regeneration periods under all working conditions is the final regeneration period.

[0011] Furthermore, through one or more methods of on-road testing, bench testing and simulation, the regeneration mileage target values ​​corresponding to different speeds under engine no-load and full-load conditions are obtained respectively, and the obtained regeneration mileage target values ​​are used as reference values ​​for the regeneration cycle.

[0012] Furthermore, the correction based on the vehicle speed includes: when the vehicle speed is less than V1, that is, in the normal operating range, setting the correction coefficient n1 to 1.0.

[0013] Furthermore, the correction based on the vehicle speed also includes: when V1<vehicle speed<V2, the correction coefficient is n2, and the range of the correction coefficient n2 is 1.0-0.8.

[0014] Furthermore, the correction based on the vehicle speed also includes: when V2<vehicle speed<V3, the correction coefficient is n3, and the range of the correction coefficient n3 is 0.8-0.5.

[0015] Furthermore, the correction based on the exhaust temperature includes: when the vehicle speed is less than V1 and the exhaust temperature is less than t1, the regeneration period correction coefficient n1 is 1.0.

[0016] Furthermore, the correction based on the exhaust temperature also includes: when V1<vehicle speed<V2, and t1<exhaust temperature<t2, the correction coefficient is n2, n2=A1 / A2.

[0017] Furthermore, the correction based on the exhaust temperature also includes: when V2<vehicle speed<V3, t2<exhaust temperature<t3, the correction coefficient is n3, n3=A2 / A3.

[0018] Furthermore, the corrected regeneration cycle is shown as follows:

[0019] h=h1*n1+h2*n2*h3*n3;

[0020] Among them, h1 is the particle collector operating time when vehicle speed is less than V1 and exhaust temperature is less than t1; h2 is the particle collector operating time when V1 is less than vehicle speed and less than V2, and t1 is less than exhaust temperature and less than t2; h3 is the particle collector operating time when V2 is less than vehicle speed and less than V3, and t2 is less than exhaust temperature and less than t3.

[0021] A second aspect of the present invention provides a diesel engine regeneration cycle control device, comprising:

[0022] The data acquisition module is configured to: respectively obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load states, and use them as the reference values ​​of the regeneration cycle;

[0023] The correction module is configured to: sequentially correct the reference value of the regeneration period based on the vehicle speed and based on the exhaust temperature, and determine the correction coefficient of the regeneration period corresponding to different engine working conditions;

[0024] The result output module is configured to determine the regeneration period under the corresponding working conditions by using the correction coefficients corresponding to the various working conditions, and the sum of the regeneration periods under all the working conditions is the final regeneration period.

[0025] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0026] Based on the carbon deposition mileage of the engine under no-load and full-load conditions, a preliminary survey is conducted to determine the corresponding regeneration mileage target value at different vehicle speeds as the benchmark value of the regeneration cycle, so that the basic regeneration mileage of the engine can be mastered; and using the speed data, vehicle speed data, carbon deposition mileage data and exhaust temperature data obtained during the preliminary survey, the benchmark regeneration cycle can be corrected based on vehicle speed and exhaust temperature, so as to determine the corresponding correction coefficient under different engine working conditions, and the sum of the regeneration cycles corresponding to multiple working conditions is used as the final regeneration cycle. It can better fit the actual operating conditions of the engine and dynamically determine the regeneration cycle of the DPF in the engine exhaust treatment system, so as to better meet the actual needs of users. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 is a schematic diagram of a regeneration cycle control flow provided by one or more embodiments of the present invention;

[0029] Figure 2 A schematic diagram of a garbage truck route spectrum provided by one or more embodiments of the present invention;

[0030] Figure 3 Schematic diagram of exhaust temperature correction during a regeneration cycle provided by one or more embodiments of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. 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 invention belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. 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.

[0034] As introduced in the background technology, some engines operating in specific environments need to determine the active regeneration cycle based on the operating conditions. However, most of the engine operating conditions are in the low-speed area. The active regeneration cycle determined in the low-speed area is too short, which is prone to frequent regeneration problems.

[0035] Therefore, the following embodiment provides a diesel engine regeneration cycle control method and device, which conducts a preliminary investigation on the carbon deposition mileage of the engine under no-load and full-load conditions, determines the regeneration mileage target values ​​corresponding to different vehicle speeds, and uses them as the reference values ​​of the regeneration cycle. The reference regeneration cycle is then corrected based on the vehicle speed and the exhaust temperature, and the correction coefficients corresponding to different engine operating conditions are determined. The sum of the regeneration cycles corresponding to multiple operating conditions is used as the final regeneration cycle.

[0036] Embodiment 1:

[0037] like Figure 1 As shown, a diesel engine regeneration cycle control method comprises the following steps:

[0038] Obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load conditions respectively, and use them as the reference values ​​of the regeneration cycle;

[0039] The reference value of the regeneration cycle is corrected based on the vehicle speed and based on the exhaust temperature in sequence, and a correction coefficient of the regeneration cycle corresponding to different engine operating conditions is determined;

[0040] The correction coefficients corresponding to various working conditions are used to determine the regeneration period under the corresponding working conditions. The sum of the regeneration periods under all working conditions is the final regeneration period.

[0041] During the operation of the diesel engine, soot enters the aftertreatment along with the exhaust gas and gradually accumulates in the DPF. When the carbon deposit reaches a certain level, the DPF needs to be regenerated to eliminate the carbon deposit in the aftertreatment.

[0042] For certain special products such as garbage trucks and other special vehicles, the DPF regeneration cycle is currently formulated during product development based on usage in common operating areas.

[0043] like Figure 2 The road spectrum of the garbage truck shown in the figure, the horizontal axis is the engine speed, and the vertical axis is the engine torque. It can be determined that about 70% of the operating conditions are common operating conditions, and the common operating condition area is the low-speed area with a speed below 1700rpm. Therefore, the regeneration cycle of this model is also calibrated according to the operating conditions in the low-speed area, without considering the use of the remaining operating areas.

[0044] During operation, the vehicle does not only operate in the common operating area. It is used in both medium and high speed areas. The carbon deposit generation rate and the passive regeneration capacity of post-treatment in the medium and high speed areas are quite different from those in the low speed common operating area. As a result, the fixed time regeneration cycle formulated according to the common operating area is different from the actual carbon deposit situation of the whole vehicle, resulting in the whole vehicle regenerating more frequently than the actual situation.

[0045] This embodiment feeds back the operating data in real time according to the actual operating conditions of the vehicle, and makes judgments according to different operating conditions. The regeneration cycle is more closely matched with the operating conditions, and the regeneration cycle design is more reasonable.

[0046] First, the carbon deposit regeneration mileage of the whole vehicle at different speeds is investigated in the unloaded state, and the regeneration mileage target values ​​corresponding to different vehicle speeds are formulated based on the actual investigation results. This target value serves as the basis for the subsequent logical correction of the regeneration mileage. Then, the whole vehicle is fully loaded and the above working conditions are repeated to obtain the regeneration mileage based on load, vehicle speed and other dimensions.

[0047] Regarding the investigation of the carbon deposit regeneration mileage of the whole vehicle, the DPF regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load conditions can be obtained through one or more methods of on-road testing, bench testing, and simulation, and the obtained regeneration mileage target values ​​are used as the reference values ​​of the regeneration cycle. In this embodiment, the DPF regeneration mileage corresponding to different vehicle speeds is determined through on-road testing.

[0048] Develop dynamic regeneration mileage correction strategies based on load and vehicle speed.

[0049] Dimension 1: First, make corrections based on vehicle speed.

[0050] When the vehicle speed is less than V1 (ie, the normal operating condition), the regeneration cycle correction coefficient n1 is set to 1.0, that is, the regeneration cycle remains unchanged.

[0051] When V1<vehicle speed<V2, the correction coefficient is n2, where n2 is between 1.0 and 0.8.

[0052] When V2 < vehicle speed < V3, the correction factor is n3, where n3 ranges from 0.8 to 0.5.

[0053] Each correction factor is determined according to the carbon deposition generation rate at different vehicle speeds during the baseline period, specifically as follows:

[0054] The vehicle speed threshold V1 for the common operating condition area is determined in advance according to the vehicle type. For example, in this embodiment, the common operating condition area of the "garbage truck" is the low-speed area with a rotational speed lower than 1700 rpm. During the on-road test, the vehicle speed range corresponding to the "low-speed area with a rotational speed lower than 1700 rpm" can be determined, thereby determining the vehicle speed threshold V1.

[0055] The carbon deposition mileage at different vehicle speeds is obtained through on-road testing. When the vehicle speed < V1, assume the carbon deposition mileage corresponds to A1;

[0056] When Vl < vehicle speed < V2, the carbon deposition mileage corresponds to A2;

[0057] When V2 < vehicle speed < V3, the carbon deposition mileage corresponds to A3;

[0058] Among them, A1 < A2 < A3, and the correction factors n1, n2, and n3 are calculated based on the ratios of A1, A2, and A3 respectively, that is, n1 = 1, n2 = A1 / A2, and n3 = A2 / A3.

[0059] The corrected regeneration period is h = h1*n1 + h2*n2 + h3*n3.

[0060] Among them, the existing regeneration period = h1 + h2 + h3. h1 is the running time when the vehicle speed < V1, h2 is the running time when V1 < vehicle speed < V2, and h3 is the running time when V2 < vehicle speed < V3. That is, the higher the vehicle speed, the higher the engine load, the slower the carbon deposition generation speed, and the longer the regeneration period.

[0061] Dimension 2: On the basis of vehicle speed correction, further correction is performed based on the exhaust temperature.

[0062] As Figure 3 shown, when the vehicle speed < V1 (i.e., the common operating condition area) and the exhaust temperature < t1, the set regeneration period correction factor n1 is 1.0, that is, the regeneration period remains unchanged.

[0063] When V1 < vehicle speed < V2 and t1 < exhaust temperature < t2, the correction factor is n2, where n2 ranges from 1.0 to 0.8.

[0064] When V2 < vehicle speed < V3 and t2 < exhaust temperature < t3, the correction factor is n3, where n3 ranges from 0.8 to 0.5.

[0065] The final corrected regeneration cycle is h=h1*n1+h2*n2*h3*n3, where h1 is the operating time when the vehicle speed is less than V1 and the exhaust temperature is less than t1, h2 is the operating time when V1 is less than vehicle speed and less than V2 and t1 is less than exhaust temperature and t2 is less than exhaust temperature and t3 is h3.

[0066] That is, the higher the vehicle speed, the higher the engine load, and the higher the exhaust temperature, the slower the carbon deposits are generated, and the longer the regeneration cycle corresponding to the corresponding operating conditions.

[0067] In this embodiment, the exhaust temperature correction is performed when the carbon deposition mileage is surveyed based on different loads (empty, full load). At the same vehicle speed, the heavier the load, the higher the engine load rate, the higher the exhaust temperature, and the stronger the passive regeneration capacity of the post-treatment (the stronger the carbon removal capacity). Therefore, on the basis of the correction based on the vehicle speed, the correction of the exhaust temperature (load) is superimposed to obtain the final correction coefficient of the vehicle speed. In this embodiment, the final correction coefficients are n1=1, n2=A1 / A2, and n3=A2 / A3.

[0068] The above method first conducts a preliminary investigation based on the carbon deposition mileage of the engine under no-load and full-load conditions, determines the corresponding regeneration mileage target value at different vehicle speeds, and uses it as the reference value of the regeneration cycle to grasp the basic regeneration mileage of the engine; and using the speed data, vehicle speed data, carbon deposition mileage data, and exhaust temperature data obtained during the preliminary investigation, the reference regeneration cycle can be corrected based on the vehicle speed and the exhaust temperature, thereby determining the corresponding correction coefficient under different engine working conditions, and taking the sum of the regeneration cycles corresponding to multiple working conditions as the final regeneration cycle. It can better fit the actual operating conditions of the engine, dynamically determine the regeneration cycle of the DPF in the engine exhaust treatment system, and thus better meet the actual needs of users.

[0069] Embodiment 2:

[0070] A diesel engine regeneration cycle control device, comprising:

[0071] The data acquisition module is configured to: respectively obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load states, and use them as the reference values ​​of the regeneration cycle;

[0072] The correction module is configured to: sequentially correct the reference value of the regeneration period based on the vehicle speed and based on the exhaust temperature, and determine the correction coefficient of the regeneration period corresponding to different engine working conditions;

[0073] The result output module is configured to determine the regeneration period under the corresponding working conditions by using the correction coefficients corresponding to the various working conditions, and the sum of the regeneration periods under all the working conditions is the final regeneration period.

[0074] First, we conduct a survey based on the carbon deposition mileage of the engine under no-load and full-load conditions, determine the corresponding regeneration mileage target value at different vehicle speeds, and use it as the benchmark value of the regeneration cycle to master the basic regeneration mileage of the engine; and make corrections to the benchmark regeneration cycle based on vehicle speed and exhaust temperature, so as to determine the corresponding correction coefficient under different engine working conditions, and use the sum of the regeneration cycles corresponding to multiple working conditions as the final regeneration cycle. It can better fit the actual operating conditions of the engine and dynamically determine the regeneration cycle of the DPF in the engine exhaust treatment system, so as to better meet the actual needs of users.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A diesel engine regeneration cycle control method, characterized in that: The following steps are involved: Obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load conditions respectively, and use them as the reference values ​​of the regeneration cycle; The reference value of the regeneration cycle is corrected based on the vehicle speed and based on the exhaust temperature in sequence, and a correction coefficient of the regeneration cycle corresponding to different engine operating conditions is determined; The correction coefficients corresponding to various working conditions are used to determine the regeneration period under the corresponding working conditions. The sum of the regeneration periods under all working conditions is the final regeneration period.

2. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: Through one or more methods of on-road testing, bench testing and simulation, the regeneration mileage target values ​​corresponding to different speeds under engine no-load and full-load conditions are obtained respectively, and the obtained regeneration mileage target values ​​are used as reference values ​​for the regeneration cycle.

3. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on vehicle speed includes: when the vehicle speed is less than V1, that is, in the normal operating area, setting the correction coefficient n1 to 1.

0.

4. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on vehicle speed also includes: when V1<vehicle speed<V2, the correction coefficient is n2, and the range of the correction coefficient n2 is 1.0~0.

8.

5. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on vehicle speed also includes: when V2<vehicle speed<V3, the correction coefficient is n3, and the range of the correction coefficient n3 is 0.8~0.

5.

6. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on the exhaust temperature includes: when the vehicle speed is less than V1 and the exhaust temperature is less than t1, the regeneration period correction coefficient n1 is 1.

0.

7. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on the exhaust temperature also includes: when V1<vehicle speed<V2, and t1<exhaust temperature<t2, the correction coefficient is n2, n2=A1 / A2.

8. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The correction based on the exhaust temperature also includes: when V2<vehicle speed<V3, t2<exhaust temperature<t3, the correction coefficient is n3, n3=A2 / A3.

9. A diesel engine regeneration cycle control method as claimed in claim 1, characterized in that: The corrected regeneration cycle is shown in the following formula: h=h1*n1+h2*n2*h3*n3; Among them, h1 is the particle collector operating time when vehicle speed is less than V1 and exhaust temperature is less than t1; h2 is the particle collector operating time when V1 is less than vehicle speed and less than V2, and t1 is less than exhaust temperature and less than t2; h3 is the particle collector operating time when V2 is less than vehicle speed and less than V3, and t2 is less than exhaust temperature and less than t3.

10. A diesel engine regeneration cycle control device, characterized in that: include: The data acquisition module is configured to: respectively obtain the regeneration mileage target values ​​corresponding to different speeds under the engine no-load and full-load states, and use them as the reference values ​​of the regeneration cycle; The correction module is configured to: sequentially correct the reference value of the regeneration period based on the vehicle speed and based on the exhaust temperature, and determine the correction coefficient of the regeneration period corresponding to different engine working conditions; The result output module is configured to determine the regeneration period under the corresponding working conditions by using the correction coefficients corresponding to the various working conditions, and the sum of the regeneration periods under all the working conditions is the final regeneration period.

Images