CN110529221B - Control method of cold-start adsorption and desorption device of plug-in engine - Google Patents

Abstract

A plug-in engine cold start adsorption and desorption device control method belongs to the field of engine emission control. The control method is characterized in that the control is based on an engine speed signal (a1), an engine cooling water temperature signal (a2) and a signal (e) of the opening times of the adsorption device. The opening and closing of the first valve (5), the second valve (11) and the third valve (12) are controlled by the electronic control unit (13), so that the adsorption device (7) is opened when the engine cooling water is not higher than 40°C; And before the adsorption device (7) reaches saturation adsorption, the adsorption device (7) is bypassed, so as to avoid the problem of early desorption of the adsorption device (7). After the adsorption device (7) is bypassed, the driver is prompted through the display unit (15) to perform desorption and regeneration of the adsorption device (7). The adsorption device (7) is desorbed and regenerated by using the desorption device (8) through the power supply plug (10) and the external power supply.

Description

A plug-in engine cold start adsorption and desorption device control method

technical field

The invention belongs to the field of engine emission control, and in particular relates to a control method of a plug-in engine cold start adsorption and desorption device.

Background technique

Since the three-way catalytic converter cannot reach the working temperature during the cold start of the engine, the HC emissions cannot be effectively converted during the cold start of the engine. In addition, the control unit ECU needs to increase the fuel injection amount to ensure the smooth start of the engine, and a large amount of unburned fuel is HC. form into the atmosphere. According to the relevant test results, in the NEDC cycle test, 90% of the HC emissions are generated in the cold start stage of the engine. Therefore, reducing the emission of polluting gases during the cold start phase of the engine has become one of the important issues to be solved urgently for the continued development of the internal combustion engine. Because of its characteristics of low temperature and high pressure adsorption and high temperature and low pressure desorption, adsorption technology is an effective means to solve the HC emission in the cold start stage of the engine. According to the relevant bench test results, under the condition of an ambient temperature of 20°C, more than 75% of the HC emissions during the cold start phase of the engine can be adsorbed in the adsorption device with the adsorption material placed.

At present, the technical bottleneck restricting the application of adsorption devices is how to realize the desorption and regeneration of adsorbent materials. The usual on-board desorption and regeneration technology is limited by the desorption time and the running state of the vehicle. The adsorption efficiency of the device during resorption. The desorption device is limited by the on-board battery system and cannot run for a long time. At present, with the gradual expansion of the construction scale of electric vehicle supporting facilities, it provides a new direction for the desorption of the engine adsorption device.

Therefore, it is particularly necessary to design an adsorption device that can not only effectively reduce the HC emission during the cold start phase of the engine, but also realize the sufficient desorption and regeneration of the adsorbent material.

Invention content:

The purpose of the present invention is to provide a method for controlling a plug-in engine cold start adsorption and desorption device, which is controlled by an engine speed signal (a1), an engine cooling water temperature signal (a2) and a signal (e) of the number of times the adsorption device is turned on in accordance with. The opening and closing of the first valve (5), the second valve (11) and the third valve (12) are controlled by the electronic control unit (13), so that the adsorption device (7) is opened when the engine cooling water is not higher than 40°C; And before the adsorption device (7) reaches saturation adsorption, the adsorption device (7) is bypassed, so as to avoid the problem of early desorption of the adsorption device (7). After the adsorption device (7) is bypassed, the driver is prompted through the display unit (15) to perform desorption and regeneration of the adsorption device (7). The adsorption device (7) is desorbed and regenerated by using the desorption device (8) through the power supply plug (10) and the external power supply.

In order to achieve the purpose of reducing the emission during the engine starting process and ensure the sufficient desorption and regeneration of the adsorbent material, the control method of a plug-in engine cold start adsorption and desorption device according to the present invention adopts the following technical solutions:

The intake pipe (1), the fourth valve (2), the engine (3), and the fourth valve (2) are connected in series with the engine (3) through the intake pipe (1); the three-way catalytic converter (4), the third valve ( 12), the exhaust pipe (14), the three-way catalytic converter (4), and the third valve (12) are connected in series with the engine (3) through the exhaust pipe (14); upstream of the third valve (12) and the three-way An adsorption pipeline (6) is connected in parallel downstream of the catalyst (4), and the first valve (5), the adsorption device (7) and the second valve (11) are connected in series on the adsorption pipeline (6) in sequence and pass through the adsorption pipeline (6) is connected to the exhaust pipe (14) downstream of the third valve (12). The adsorption device (7) and the desorption device (8) are connected with the fourth valve (2) through the desorption pipeline (9). The desorption device (8) is provided with a desorption device and can store the pollutants desorbed by the adsorption device (7). The power plug (10) and the desorption device (8) are connected in series to provide the external power supply required for the operation of the desorption device (8). The electronic control unit (13) is connected to the display unit (15) through the display unit signal (j) line and receives the engine speed signal (a1), the engine cooling water temperature signal (a2), the adsorption device signal (e), the power plug signal ( f), control the opening and closing of the first valve (b), the opening and closing of the second valve (d), the opening and closing of the third valve (c), the opening and closing of the fourth valve (h) and the opening and closing of the desorption device (g).

When the engine is started, the electronic control unit (13) receives the engine coolant temperature signal (a1), the engine speed signal (a2) and the adsorption device opening times signal (e). When the engine coolant temperature _tw < 40°C and the engine speed When n _e < 1200 rpm and the number of times of opening the adsorption device (e) m < m ₀ (m ₀ is the maximum continuous adsorption times when the adsorption efficiency of the adsorption material in the adsorption device (7) is not less than μ%), the electronic control unit (13) Control to open the first valve (5) and the second valve (11) and close the third valve (12), so that the exhaust gas from the engine (3) passes through the exhaust pipe (14) and the adsorption pipeline (6) ) into the adsorption device (7) for adsorption and purification, and the electronic control unit (13) records the number of times the adsorption device is opened signal (e) times m=m′+1 (m′ is the number of times the adsorption device is opened before adsorption). When the engine coolant temperature t _w ≥ 40°C or the engine speed n _e ≥ 1200 rpm or the adsorption device opening times signal (e) m ≥ m ₀ , the electronic control unit (13) controls to close the first valve (5) and The second valve (11) and the third valve (12) are opened, so that the exhaust gas discharged from the engine (3) is discharged to the atmosphere through the exhaust pipe (14).

The electronic control unit (13) receives the signal (e) of the opening times of the adsorption device, and when the signal (e) of the opening times of the adsorption device m ≥ m ₀ , the electronic control unit (13) sends a signal to the display unit (15) to remind the driver The personnel adsorption device (7) is saturated and needs to be desorbed and regenerated. When the electronic control unit (13) detects that the power plug (10) is connected to the external power supply, the electronic control unit (13) closes the first valve (5) and the second valve (11), opens the desorption device (8), and desorbs the The attachment device (8) starts the desorption process, and the set time is 20 minutes. At the same time, the electronic control unit (13) controls the desorption device (8) to store the pollutants desorbed in the adsorption device (7) in the desorption device (8).

When the engine is started, the electronic control unit (13) receives the engine speed signal (a2), and when the engine speed n _e ≥ 1200 rpm, the electronic control unit (13) opens the fourth valve (2), which is stored in the desorption device The pollutants in (8) enter the engine (3) for combustion after passing through the desorption pipeline (9) through the intake pipe (1) under the action of the vacuum degree of the intake pipe (1).

The present invention aims to propose a control method for a plug-in engine cold start adsorption and desorption device, the advantages of which are:

In this method, the device enables the adsorption device to be opened only when the engine cooling water is not higher than 40°C, and bypasses the adsorption device before the adsorption device reaches saturation adsorption, so as to ensure the high single adsorption efficiency of the adsorption device and avoid premature desorption. question. The external power supply can provide electricity for the desorption and regeneration of the adsorption device, which improves the desorption rate of the adsorption device, and solves the problem that the adsorption device is difficult to desorb on the vehicle. It has certain innovation and application prospects.

Description of drawings

Fig. 1 structure and working principle diagram of the present invention

In the figure: 1. Intake pipe, 2. Fourth valve, 3. Engine, 4. Three-way catalytic converter, 5. First valve, 6. Adsorption pipeline, 7. Adsorption device, 8. Desorption device, 9. Desorption pipeline, 10, Power plug, 11, Second valve, 12, Third valve, 13, Electronic control unit, 14, Exhaust pipe, 15, Display unit

Figure 2 shows the continuous adsorption curve of activated carbon material for HC emissions when the engine is started. It can be seen from the change trend of the curve in the figure that with the increase of adsorption times, the HC emission after adsorption shows a gradual increase trend, which indicates that the adsorption efficiency of the adsorbent gradually decreases during the continuous adsorption process. Therefore, in order to ensure that the adsorption efficiency of a single adsorption is not lower than a certain value (eg 50%), it is necessary to set the maximum number of adsorption times.

Figure 3 shows the continuous adsorption efficiency of activated carbon material for HC emissions when the engine is started. It can be seen from the figure that in the continuous adsorption process, the adsorption efficiency gradually decays due to the saturation of the micropores. Therefore, in order to ensure that the adsorption efficiency of a single adsorption is not lower than a certain value (eg μ50%), the maximum number of adsorptions needs to be set. In the figure, it is three times under the condition of activated carbon filling amount of 300 g.

Figure 4 shows the contaminant desorption curve during electric heating. It can be seen from the figure that when the strategy of external power supply heating and desorption is adopted, the heating device can heat up rapidly, and the pollutants are quickly desorbed, and the desorption efficiency can reach more than 80% within 20 minutes.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

The purpose of the present invention is to provide a method for controlling a plug-in engine cold start adsorption and desorption device, which is controlled by an engine speed signal (a1), an engine cooling water temperature signal (a2) and a signal (e) of the number of times the adsorption device is turned on in accordance with. The opening and closing of the first valve (5), the second valve (11) and the third valve (12) are controlled by the electronic control unit (13), so that the adsorption device (7) is opened when the engine cooling water is not higher than 40°C; And before the adsorption device (7) reaches saturation adsorption, the adsorption device (7) is bypassed, so as to avoid the problem of early desorption of the adsorption device (7). After the adsorption device (7) is bypassed, the driver is prompted through the display unit (15) to perform desorption and regeneration of the adsorption device (7). The adsorption device (7) is desorbed and regenerated by using the desorption device (8) through the power supply plug (10) and the external power supply.

In order to achieve the purpose of reducing the emission during the engine starting process and ensure the sufficient desorption and regeneration of the adsorbent material, the control method of a plug-in engine cold start adsorption and desorption device according to the present invention adopts the following technical solutions:

As shown in Figure 1, it includes: an intake pipe (1), a fourth valve (2), an engine (3), and the fourth valve (2) is connected in series with the engine (3) through the intake pipe (1); a three-way catalytic converter (4) , the third valve (12), the exhaust pipe (14), the three-way catalytic converter (4), and the third valve (12) are connected in series with the engine (3) through the exhaust pipe (14); in the third valve (12) ) upstream and downstream of the three-way catalytic converter (4) are connected in parallel with an adsorption pipeline (6), and the first valve (5), the adsorption device (7) and the second valve (11) are connected in series on the adsorption pipeline (6) in sequence It is connected with the exhaust pipe (14) downstream of the third valve (12) through the adsorption pipeline (6). The adsorption device (7) and the desorption device (8) are connected with the fourth valve (2) through the desorption pipeline (9). The desorption device (8) is provided with a desorption device and can store the pollutants desorbed by the adsorption device (7). The power plug (10) and the desorption device (8) are connected in series to provide the external power supply required for the operation of the desorption device (8). The electronic control unit (13) is connected to the display unit (15) through the display unit signal (j) line and receives the engine speed signal (a1), the engine cooling water temperature signal (a2), the adsorption device signal (e), the power plug signal ( f), control the opening and closing of the first valve (b), the opening and closing of the second valve (d), the opening and closing of the third valve (c), the opening and closing of the fourth valve (h) and the opening and closing of the desorption device (g).

When the engine is started, the electronic control unit (13) receives the engine coolant temperature signal (a1), the engine speed signal (a2) and the adsorption device opening times signal (e). When the engine coolant temperature _tw < 40°C and the engine speed When n _e < 1200 rpm and the number of times of opening the adsorption device (e) m < m ₀ (m ₀ is the maximum continuous adsorption times when the adsorption efficiency of the adsorption material in the adsorption device (7) is not less than 50%), at this time, It is considered that the engine (3) is in the cold start stage and the adsorption device (7) has not been saturated, therefore, the electronic control unit (13) controls to open the first valve (5) and the second valve (11) and close the third valve (12) ), so that the exhaust gas discharged from the engine (3) at this time enters the adsorption device (7) through the exhaust pipe (14) and the adsorption pipeline (6) for adsorption and purification, and the electronic control unit (13) records the adsorption device opening times signal (e ) times m=m′+1 (m′ is the opening times of the adsorption device before adsorption). When the engine coolant temperature t _w ≥ 40°C or the engine speed n _e ≥ 1200 rpm or the adsorption device opening times signal (e) m ≥ m ₀ , at this time, it can be considered that the engine (3) cold start stage has ended or The adsorption device (7) has been saturated with adsorption, therefore, the electronic control unit (13) controls to close the first valve (5) and the second valve (11) and open the third valve (12), so that the engine (3) discharges at this time. The exhaust gas is discharged to the atmosphere through the exhaust pipe (14).

The electronic control unit (13) receives the signal (e) of the opening times of the adsorption device, and when the signal (e) of the opening times of the adsorption device m ≥ m ₀ , the electronic control unit (13) sends a signal to the display unit (15) to remind the driver The personnel adsorption device (7) is saturated and needs to be desorbed and regenerated. When the driver turns on the external power supply, that is, when the electronic control unit (13) detects that the power plug (10) is connected to the external power supply, the electronic control unit (13) closes the first valve (5) and the second valve (11), Turn on the desorption device (8), and the desorption device (8) starts the desorption process, and the set time is 20 minutes. At the same time, the electronic control unit (13) controls the desorption device (8) to store the pollutants desorbed in the adsorption device (7) in the desorption device (8).

When the engine is started, the electronic control unit (13) receives the engine speed signal (a2). When the engine speed n _e ≥ 1200 rpm, it is considered that the engine (3) has run smoothly. Therefore, the electronic control unit (13) ) Open the fourth valve (2), the pollutants stored in the desorption device (8) enter the engine through the desorption pipeline (9) through the intake pipe (1) under the action of the vacuum degree of the intake pipe (1). (3) burning in.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (1)

1. A control method of a plug-in engine cold start adsorption and desorption device, characterized in that: an intake pipe (1), a fourth valve (2), an engine (3), and the fourth valve (2) passes through an intake pipe ( 1) Connected in series with the engine (3); the three-way catalytic converter (4), the third valve (12), the exhaust pipe (14), the three-way catalytic converter (4), and the third valve (12) pass through the exhaust pipe (14) is connected in series with the engine (3); an adsorption pipeline (6), a first valve (5) and an adsorption device (7) are connected in parallel with the upstream of the third valve (12) and the downstream of the three-way catalytic converter (4). and the second valve (11) are connected in series on the adsorption pipeline (6) in turn and are connected with the exhaust pipe (14) downstream of the third valve (12) through the adsorption pipeline (6); The attachment device (8) is connected with the fourth valve (2) through the desorption pipeline (9); the desorption device (8) is provided with a desorption device and can store the pollutants desorbed by the adsorption device (7); The power plug (10) and the desorption device (8) are connected in series to provide an external power supply required for the operation of the desorption device (8); the electronic control unit (13) is connected to the display unit (15) through the display unit signal (j) line ) Connect and receive engine speed signal (a1), engine cooling water temperature signal (a2), adsorption device opening times signal (e), power plug signal (f), and control the opening and closing of the first valve (b) and the opening and closing of the second valve. Close (d), open and close the third valve (c), open and close the fourth valve (h), and open and close the desorption device (g); The first valve (5) and the second valve (11) are controlled by the electronic control unit (13) based on the engine speed signal (a1), the engine cooling water temperature signal (a2) and the number of times the adsorption device is opened (e) and the opening and closing of the third valve (12), so that the adsorption device (7) is opened when the engine cooling water is not higher than 40 °C; and the adsorption device (7) is bypassed before the adsorption device (7) reaches saturation adsorption, to avoid The problem of early desorption occurs in the adsorption device (7); after the adsorption device (7) is bypassed, the driver is prompted to perform desorption and regeneration of the adsorption device (7) on the display unit (15) through the display unit signal (j); The adsorption device (7) is desorbed and regenerated by means of the desorption device (8) by energizing the power plug (10) and an external power source; It includes the following control stages: (1) When the engine is started, the electronic control unit (13) receives the engine coolant temperature signal (a1), the engine speed signal (a2) and the adsorption device opening times signal (e). When the engine coolant temperature t _w <40°C And when the engine speed n _e < 1200 rpm and the number of times of opening the adsorption device signal (e) m < m ₀ , m ₀ is the maximum continuous adsorption times when the adsorption efficiency of the adsorption material in the adsorption device (7) is not less than 50%; The control unit (13) controls the opening of the first valve (5) and the second valve (11) and the closing of the third valve (12), so that the exhaust gas discharged from the engine (3) at this time passes through the exhaust pipe (14) and the adsorption pipeline (6) Enter the adsorption device (7) to carry out adsorption and purification, and the electronic control unit (13) records the number of times the adsorption device is opened. When the temperature t _w ≥ 40°C or the engine speed n _e ≥ 1200 rpm or the number of times the adsorption device is opened (e) m ≥ m ₀ , the electronic control unit (13) controls to close the first valve (5) and the second valve ( 11) and open the third valve (12), so that the exhaust gas discharged from the engine (3) is discharged to the atmosphere through the exhaust pipe (14); (2) The electronic control unit (13) receives the signal (e) of the opening times of the adsorption device, and when the signal (e) of the opening times of the adsorption device is m≥m ₀ , the electronic control unit (13) sends a signal to the display unit (15), using To remind the driver that the adsorption device (7) is saturated and needs to be desorbed and regenerated; when the electronic control unit (13) detects that the power plug (10) is connected to the external power supply, the electronic control unit (13) closes the first valve (5). ) and the second valve (11), open the desorption device (8), the desorption device (8) opens the desorption process, and the set time of the desorption process is 20 minutes; at the same time, the electronic control unit (13) controls the desorption device (8) storing the pollutants desorbed in the adsorption device (7) in the desorption device (8); (3) When the engine is started, the electronic control unit (13) receives the engine speed signal (a2), and when the engine speed n _e ≥ 1200 rpm, the electronic control unit (13) opens the fourth valve (2), which is stored in the The pollutants in the desorption device (8), under the action of the vacuum degree of the intake pipe (1), pass through the desorption pipeline (9) through the intake pipe (1) and then enter the engine (3) for combustion.

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