A method for reducing white smoke generation during DPF stationary regeneration

Abstract

The application discloses a method for reducing white smoke generated during DPF parking regeneration, and belongs to the technical field of engine control. The method is used for solving the technical problem of white smoke generated during DPF parking regeneration, and comprises the following steps: calibrating the exhaust temperature pulse MAP according to different engine speeds and different temperatures of the input end of a DOC aftertreatment device in advance; obtaining the actual temperature T4 and the actual speed of the input end of the DOC aftertreatment device in real time during DPF parking regeneration; when the actual temperature T4 is less than 270 DEG C, the exhaust temperature pulse MAP is inquired according to the actual temperature T4 and the actual speed; when the actual temperature T4 reaches 270 DEG C, the cycle fuel injection amount pulse MAP is inquired according to the cycle fuel injection amount and the actual speed; the target throttle opening, the target advance angle, the target rail pressure, the target post-injection 1 fuel injection amount and the target post-injection 2 fuel injection amount are obtained; and the engine is controlled to operate according to the target throttle opening, the target advance angle, the target rail pressure, the target post-injection 1 fuel injection amount and the target post-injection 2 fuel injection amount, so as to reduce the generation of white smoke and the DPF parking regeneration time.

Description

Technical Field

[0001] This invention relates to the field of engine control technology, and more specifically, to a method for reducing white smoke generated during DPF parking regeneration. Background Technology

[0002] Currently, during DPF parking regeneration, the existing strategy uses a cyclic injection quantity pulse spectrum MAP to control throttle opening, advance angle, rail pressure, and the quantities of post-injection 1 and post-injection 2. The post-injection 2 quantity calibration in the cyclic injection quantity pulse spectrum MAP is as follows: Figure 1 As shown. Excessive oil injection during the heating stage of the cold engine post-treatment process can easily lead to white smoke. The white smoke is mainly caused by the escape of HC and CO. HC and CO cannot be effectively removed before the DOC temperature reaches 270 degrees Celsius. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide a method for reducing the white smoke generated during DPF parking regeneration.

[0004] The technical solution of the present invention is: a method for reducing white smoke generated during DPF parking regeneration, characterized in that it includes:

[0005] Pre-calibrate the corresponding throttle opening, advance angle, rail pressure, fuel injection 1 quantity, and fuel injection 2 quantity according to different engine speeds and different temperatures at the DOC after-processor input terminal, and create an exhaust temperature pulse spectrum MAP that can reduce fuel injection to slowly heat the DOC after-processor and reduce white smoke generation.

[0006] During DPF parking regeneration, the actual temperature T4 and actual speed at the DOC after-processor input terminal are obtained in real time;

[0007] When the actual temperature T4 is less than 270℃, the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity are obtained by querying the exhaust temperature pulse spectrum MAP based on the actual temperature T4 and actual speed. The engine operation is then controlled based on the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity to reduce white smoke production.

[0008] When the actual temperature T4 reaches 270℃, the engine's cyclic fuel injection quantity is acquired in real time. Based on the cyclic fuel injection quantity and the actual speed, the cyclic fuel injection quantity pulse spectrum MAP is queried to obtain the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity. The engine operation is controlled based on the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity to reduce the DPF parking regeneration time.

[0009] As a further improvement, the heating rate of the DOC post-processor is no more than 50°C / s.

[0010] Furthermore, at the same engine speed, the throttle opening of the exhaust temperature pulse spectrum MAP is greater than the throttle opening of the circulating fuel injection quantity pulse spectrum MAP.

[0011] Furthermore, when the engine speed is less than or equal to 1400 r / min, the target fuel injection quantity after the exhaust temperature pulse spectrum MAP is 0.

[0012] Furthermore, when the temperature at the DOC post-processor input is less than or equal to 50°C, the target post-injection fuel quantity in the exhaust temperature pulse spectrum MAP is 0.

[0013] Furthermore, a temperature sensor is installed on the exhaust pipe at the DOC post-processor input to obtain the actual temperature T4 at the DOC post-processor input in real time.

[0014] Furthermore, after obtaining the actual temperature T4 at the DOC post-processor input, it needs to undergo smoothing filtering.

[0015] Beneficial effects

[0016] Compared with the prior art, the advantages of this invention are as follows:

[0017] This invention refines the T4 exhaust temperature, allowing the DOC to be slowly heated before reaching its 270°C ignition temperature by controlling engine operation according to the exhaust temperature pulse spectrum MAP. This reduces fuel injection, increases throttle opening, and decreases white smoke production. When the actual T4 temperature reaches 270°C, the engine operation is controlled according to the cyclic fuel injection quantity pulse spectrum MAP, which can quickly heat the DOC to the specified temperature, thereby reducing DPF parking regeneration time and ensuring DPF parking regeneration efficiency. Attached Figure Description

[0018] Figure 1 A schematic diagram of the existing cyclic fuel injection pulse spectrum;

[0019] Figure 2 This is a schematic diagram of the exhaust pulse spectrum MAP of the present invention;

[0020] Figure 3 This is a schematic diagram of the installation of the temperature sensor in this invention;

[0021] Figure 4 This is the control flowchart of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0023] See Figures 1-4A method for reducing white smoke generated during DPF parking regeneration includes:

[0024] Pre-calibrate the corresponding throttle opening, advance angle, rail pressure, fuel injection 1 quantity, and fuel injection 2 quantity according to different engine speeds and different temperatures at the DOC after-processor input terminal, and create an exhaust temperature pulse spectrum MAP that can reduce fuel injection to slowly heat the DOC after-processor and reduce white smoke generation.

[0025] During DPF parking regeneration, the actual temperature T4 and actual speed at the DOC after-processor input terminal are obtained in real time;

[0026] When the actual temperature T4 is less than 270℃, the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity are obtained by querying the exhaust temperature pulse spectrum MAP based on the actual temperature T4 and actual speed. The engine operation is then controlled based on these parameters. By refining the T4 exhaust temperature, the DOC can be slowly heated before reaching the 270-degree ignition temperature, reducing fuel injection, increasing the throttle opening, and reducing white smoke production.

[0027] When the actual temperature T4 reaches 270℃, the engine's cyclic fuel injection quantity is acquired in real time. Based on the cyclic fuel injection quantity and the actual speed, the cyclic fuel injection quantity pulse spectrum MAP is queried to obtain the target throttle opening, target advance angle, target rail pressure, target post-injection 1 quantity, and target post-injection 2 quantity. The engine operation is controlled according to the target throttle opening, target advance angle, target rail pressure, target post-injection 1 quantity, and target post-injection 2 quantity. The DOC can be quickly heated to the specified temperature to reduce the DPF parking regeneration time and ensure the DPF parking regeneration efficiency.

[0028] In this embodiment, the heating rate of the DOC post-processor is no more than 50°C / s.

[0029] At the same engine speed, the throttle opening of the exhaust temperature pulse spectrum MAP is greater than that of the cyclic fuel injection quantity pulse spectrum MAP to reduce white smoke production. When the engine speed is less than or equal to 1400 r / min, the target post-injection quantity of the exhaust temperature pulse spectrum MAP is 0. When the temperature at the DOC after-treatment input is less than or equal to 50°C, the target post-injection quantity of the exhaust temperature pulse spectrum MAP is also 0 to reduce fuel injection at low temperatures.

[0030] Temperature sensor A is installed on the exhaust pipe at the DOC post-processor input to obtain the actual temperature T4 at the DOC post-processor input in real time.

[0031] Preferably, after obtaining the actual temperature T4 at the DOC post-processor input, it needs to be smoothed and filtered to reduce the impact of temperature T4 abrupt changes or interference.

[0032] This invention controls engine operation based on exhaust temperature pulse spectrum MAP when T4 is less than 270℃; and controls engine operation based on cycle fuel injection quantity pulse spectrum MAP when T4 reaches 270℃; it can reduce white smoke generation and DPF parking regeneration time while ensuring DPF parking regeneration efficiency.

[0033] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for reducing white smoke generated during DPF parking regeneration, characterized in that, include: Pre-calibrate the corresponding throttle opening, advance angle, rail pressure, fuel injection 1 quantity, and fuel injection 2 quantity according to different engine speeds and different temperatures at the DOC after-processor input terminal, and create an exhaust temperature pulse spectrum MAP that can reduce fuel injection to slowly heat the DOC after-processor and reduce white smoke generation. During DPF parking regeneration, the actual temperature T4 and actual speed at the DOC after-processor input terminal are obtained in real time; When the actual temperature T4 is less than 270℃, the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity are obtained by querying the exhaust temperature pulse spectrum MAP based on the actual temperature T4 and actual speed. The engine operation is then controlled based on the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity to reduce white smoke production. When the actual temperature T4 reaches 270℃, the engine's cyclic fuel injection quantity is acquired in real time. Based on the cyclic fuel injection quantity and the actual speed, the cyclic fuel injection quantity pulse spectrum MAP is queried to obtain the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity. The engine operation is controlled based on the target throttle opening, target advance angle, target rail pressure, target post-injection 1 fuel quantity, and target post-injection 2 fuel quantity to reduce the DPF parking regeneration time. At the same speed, the throttle opening of the exhaust temperature pulse spectrum MAP is greater than the throttle opening of the circulating fuel injection quantity pulse spectrum MAP. When the engine speed is less than or equal to 1400 r / min, the target fuel injection quantity after the exhaust temperature pulse spectrum MAP is 0; When the temperature at the DOC post-processor input is less than or equal to 50°C, the target post-injection fuel quantity in the exhaust temperature pulse spectrum MAP is 0.

2. The method for reducing white smoke generated during DPF regeneration in parking conditions according to claim 1, characterized in that, The temperature rise rate of the DOC post-processor should be no more than 50℃ / s.

3. A method for reducing white smoke generated during DPF regeneration in parking conditions according to any one of claims 1-2, characterized in that, A temperature sensor is installed on the exhaust pipe at the DOC post-processor input to obtain the actual temperature T4 at the DOC post-processor input in real time.

4. The method for reducing white smoke generated during DPF regeneration in parking conditions according to claim 1, characterized in that, After obtaining the actual temperature T4 at the DOC input terminal, it needs to undergo smoothing filtering.

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