CN116146314A - Engine aftertreatment temperature control method and device, electronic equipment and medium - Google Patents

Abstract

The application discloses a method, a device, electronic equipment and a medium for controlling post-treatment temperature of an engine, wherein the method comprises the steps of responding to an engine starting instruction, determining that the temperature of the water of the engine is lower than a preset first temperature threshold value, and executing first thermal management operation; if the temperature of the air inlet of the ccDOC system is monitored to rise to a preset second temperature threshold value, based on the target air outlet temperature, the air inlet temperature and the exhaust gas mass flow of the ccDOC system, the feedforward control fuel injection quantity of in-cylinder post-injection is obtained; taking the actually measured temperature of the air outlet of the ccDOC system as a feedback value, and controlling the fuel injection quantity based on the target temperature of the air outlet, the air inlet temperature and the feedforward of the ccDOC system to obtain the closed-loop control fuel injection quantity of the in-cylinder post-injection; based on the oil injection accounting value and a preset oil injection range threshold value, obtaining in-cylinder post-injection target oil injection quantity; and performing in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection amount to adjust the air outlet temperature of the ccDOC system to the air outlet target temperature.

Description

A temperature control method, device, electronic equipment and medium for aftertreatment of an engine

technical field

The present application relates to the technical field of automotive electronics, in particular to a method, device, electronic equipment and medium for controlling the temperature of an engine aftertreatment.

Background technique

Engines using the SCR after-treatment system need to inject urea into the SCR to react the NOx in the exhaust gas and generate non-toxic and non-polluting N ₂ and H ₂ O at the same time. As environmental protection requirements become more and more stringent, for example, environmental protection regulations in some regions require the detection of NOx emissions after 2 kilometers, so improving the SCR conversion efficiency at low temperature and cold start is very important to meet the current emission requirements.

At present, in the related art, the engine post-treatment during the cold start process is usually unable to effectively intervene, resulting in low conversion efficiency of the low-temperature cold start SCR in the prior art.

Contents of the invention

Embodiments of the present application provide a method, device, electronic equipment, and medium for controlling engine aftertreatment temperature, which can improve SCR conversion efficiency at low-temperature cold start.

In the first aspect, the embodiment of the present application provides an engine aftertreatment temperature control method, which is applied to the exhaust aftertreatment system, and the exhaust aftertreatment system includes a close-coupled oxidation catalytic conversion system connected to the engine exhaust outlet in sequence through the exhaust pipe. ccDOC system, tightly coupled selective catalytic converter ccSCR system, selective catalytic converter SCR post-treatment system; the method includes:

In response to the engine start command, it is determined that the engine water temperature is lower than a preset first temperature threshold, and a first thermal management operation is performed; the first thermal management operation is used to increase the intake air temperature of the ccDOC system;

If it is detected that the intake air temperature of the ccDOC system has risen to the preset second temperature threshold, based on the target outlet temperature of the ccDOC system, the intake air temperature and the mass flow rate of exhaust gas, the front feed-forward control fuel injection quantity; taking the measured temperature of the gas outlet of the ccDOC system as a feedback value, based on the target temperature of the gas outlet of the ccDOC system, the intake air temperature and the fuel injection quantity of the feedforward control, the post-injection in-cylinder is obtained Closed-loop control of fuel injection quantity;

Based on the fuel injection calculation value and the preset fuel injection range threshold, the target fuel injection quantity of post-injection in the cylinder is obtained; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity;

An in-cylinder post-injection operation is performed based on the in-cylinder post-injection target fuel injection amount to adjust the outlet gas temperature of the ccDOC system to the outlet gas target temperature.

The above method is applied to the exhaust aftertreatment system, and the exhaust aftertreatment system includes a close-coupled oxidation catalytic converter ccDOC system connected to the engine exhaust outlet through an exhaust pipe, a close-coupled selective catalytic conversion device ccSCR system, A selective catalytic converter SCR aftertreatment system; by responding to an engine start command, determining that the engine water temperature is lower than a preset first temperature threshold, and performing a first thermal management operation; the first thermal management operation is used to make the ccDOC The intake air temperature of the system is increased; if it is detected that the intake air temperature of the ccDOC system rises to the preset second temperature threshold, based on the target outlet temperature of the ccDOC system, the intake air temperature and the mass flow rate of exhaust gas, Obtain the feed-forward control fuel injection quantity of post-injection in the cylinder; take the measured temperature of the gas outlet of the ccDOC system as a feedback value, based on the target temperature of the gas outlet of the ccDOC system, the intake air temperature and the fuel injection quantity of the feedforward control , to obtain the closed-loop control fuel injection quantity of the rear injection in the cylinder; based on the fuel injection calculation value and the preset fuel injection range threshold, the target fuel injection quantity of the rear injection in the cylinder is obtained; the fuel injection calculation value is the feedforward control injection The sum of the fuel quantity and the closed-loop control fuel injection quantity; the in-cylinder post-injection operation is performed based on the in-cylinder post-injection target fuel injection quantity, so as to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature. In this method, a ccDOC system and a ccSCR system are added behind the exhaust port of the engine, and the aftertreatment exhaust gas is thermally managed when the engine is cold-started, thereby increasing the aftertreatment temperature and reducing NOx emissions when the engine is cold-started, Improve low temperature cold start SCR conversion efficiency.

In a possible implementation manner, the fuel injection range threshold includes a fuel injection upper limit value; the calculation of the fuel injection calculation value and the preset fuel injection range threshold to obtain the post-injection target fuel injection amount in the cylinder includes:

Obtain the fuel injection upper limit value of the engine;

If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, the fuel injection calculation value is used as the in-cylinder post-injection target fuel injection quantity;

If the fuel injection calculated value is greater than the fuel injection upper limit, the fuel injection upper limit is used as the in-cylinder post-injection target fuel injection amount.

The above method, by determining the target fuel injection volume of the post-injection in the cylinder according to the preset fuel injection upper limit, can prevent the fuel injection volume of the post-injection in the cylinder from being too high more quickly and efficiently, and realize the fuel injection based on the upper limit of the fuel injection. Stable emission can limit the amount of NOx generated when the engine starts cold, and improve the SCR conversion efficiency at low temperature cold start.

In a possible implementation manner, the obtaining the fuel injection upper limit value of the engine includes:

Obtain the real-time rotational speed and real-time torque of the engine;

Based on the real-time rotational speed and the real-time torque query the preset fuel injection boundary MAP map to obtain the fuel injection upper limit value; the fuel injection boundary MAP map is the mapping relationship between engine speed and engine torque and fuel injection boundary value .

The above method can obtain the real-time rotational speed and real-time torque of the engine; query the preset fuel injection boundary MAP map based on the real-time rotational speed and the real-time torque to obtain the upper limit value of the fuel injection; the fuel injection boundary MAP The figure shows the mapping relationship between engine speed, engine torque and fuel injection boundary value. The method determines the fuel injection upper limit corresponding to the real-time rotational speed and real-time torque of the engine according to the preset mapping relationship between the engine speed and the engine torque and the fuel injection boundary value, and can determine the fuel injection upper limit value more quickly and efficiently. Limit value, which can more quickly and efficiently prevent the fuel injection volume of post-injection in the cylinder from being too high, and realize stable emission based on the fuel injection upper limit value, thereby limiting the amount of NOx generated when the engine starts cold, and improving SCR conversion at low temperature cold start efficiency.

In a possible implementation manner, the feed-forward control fuel injection amount of the rear injection in the cylinder is obtained based on the target temperature of the outlet gas of the ccDOC system, the intake air temperature and the mass flow rate of the exhaust gas, including:

Obtain the target temperature of the outlet gas of the ccDOC system, and the conversion efficiency of hydrocarbons and HCs;

Obtaining the exhaust gas mass flow rate, the intake air temperature, fuel calorific value and exhaust thermal fusion value of the engine;

Taking the difference between the target air outlet temperature and the intake air temperature to obtain a temperature difference value;

multiplying the mass flow rate of the exhaust gas by the thermal melting value of the exhaust gas and the temperature difference value to obtain the demand for heat release;

The heat release demand, the fuel calorific value and the HC conversion efficiency are quotiented to obtain the feed-forward control fuel injection quantity of the in-cylinder rear injection.

In the above method, the temperature difference value is obtained by taking the difference between the outlet gas target temperature and the intake air temperature, and then multiplying the mass flow rate of the exhaust gas, the exhaust thermal melting value and the temperature difference value to obtain the discharge Then, based on the heat release demand, the fuel calorific value and the HC conversion efficiency, the feedforward control fuel injection quantity of the in-cylinder rear injection is determined. In this method, by adjusting the feed-forward control fuel injection quantity of the post-injection in cylinder by combining the thermal melting value of the exhaust gas, the fuel calorific value and the HC conversion efficiency, not only the after-treatment temperature is increased, but also the NOx when the engine is cold-started can be reduced Emissions can also enhance the control accuracy of the post-injection fuel injection volume in the cylinder, and further improve the SCR conversion efficiency at low temperature and cold start.

In a possible implementation manner, the acquiring the HC conversion efficiency of the ccDOC system includes:

Based on the intake air temperature and the exhaust gas mass flow rate, query a preset conversion rate MAP map to obtain the hydrocarbon HC conversion efficiency of the ccDOC system of the engine;

Wherein, the conversion rate MAP map is a mapping relationship between the intake temperature of the ccDOC system, the mass flow rate of exhaust gas of the engine, and the fuel conversion efficiency of the ccDOC system.

In the above method, based on the intake air temperature and the exhaust gas mass flow rate, query a preset conversion rate MAP map to obtain the hydrocarbon conversion efficiency of the ccDOC system of the engine; wherein, the conversion rate MAP The figure shows the mapping relationship between the intake temperature of the ccDOC system and the mass flow rate of the engine exhaust gas and the fuel conversion efficiency of the ccDOC system. The method determines the carbon content of the ccDOC system corresponding to the intake air temperature and the exhaust gas mass flow according to the preset mapping relationship between the intake air temperature of the ccDOC system and the mass flow rate of exhaust gas of the engine and the fuel conversion efficiency of the ccDOC system. Hydrogen HC conversion efficiency can more quickly and efficiently determine the hydrocarbon HC conversion efficiency of the ccDOC system, and can more accurately and efficiently determine the feed-forward control fuel injection volume, so as to not only increase the aftertreatment temperature, but also reduce the engine cold start. NOx emissions can also enhance the accuracy of the control of the fuel injection volume of the post-injection cylinder, improve the real-time performance of the engine after-treatment temperature control under cold start, and further improve the SCR conversion efficiency at low temperature cold start.

In a possible implementation, the method further includes:

If it is detected that the engine water temperature is higher than the first temperature threshold, the first heat management operation and the in-cylinder post-injection operation are stopped.

In the above method, if it is detected that the engine water temperature is higher than the first temperature threshold, the first thermal management operation and the in-cylinder post-injection operation are stopped. In this method, when it is detected that the engine water temperature is higher than the first temperature threshold, the first thermal management operation and the in-cylinder post-injection operation are stopped, so that the engine aftertreatment temperature can be adjusted based on the engine water temperature during the cold start process. The continuous control of the engine is simple and easy, and reduces the calculation amount of the engine after-treatment temperature control, which can effectively increase the after-treatment temperature during the cold start process, reduce the NOx emission during the cold start of the engine, and improve the SCR conversion efficiency of the low-temperature cold start.

In a possible implementation manner, the intake air temperature is obtained from a first temperature sensor at the front end of the ccDOC system; the actual outlet gas temperature is obtained from a second temperature sensor between the ccDOC system and the ccSCR system .

In a possible implementation manner, the measured outlet air temperature of the ccDOC system is used as a feedback value, based on the outlet air target temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection quantity, to obtain The closed-loop control of fuel injection quantity after in-cylinder injection includes:

Obtain the measured temperature of the outlet gas of the ccDOC system;

Comparing the measured temperature of the outlet gas with the target temperature of the outlet gas;

According to the comparison result of the measured temperature of the outlet gas and the target temperature of the outlet gas, an adjustment amount for adjusting the fuel injection quantity of the feedforward control of the post-injection in the cylinder is determined as the closed-loop control fuel injection quantity of the post-injection in the cylinder.

In the above method, the measured temperature of the gas outlet of the ccDOC system is obtained; the measured temperature of the gas outlet is compared with the target temperature of the gas outlet; The adjustment amount adjusted by the feed-forward control fuel injection quantity is used as the closed-loop control fuel injection quantity of post-injection in the cylinder. The method compares the actual measured temperature of the outlet gas with the target temperature of the outlet gas; according to the comparison result between the actual measured temperature of the outlet gas and the target temperature of the outlet gas, it is determined to adjust the feedforward control fuel injection quantity of the rear injection in the cylinder The adjustment amount makes it possible to realize the continuous control of the engine aftertreatment temperature in the cold start process based on the measured temperature of the outlet gas of the ccDOC system, improve the control accuracy and control efficiency of the engine aftertreatment temperature in the cold start process, and effectively improve the cold start process. The post-treatment temperature in the middle can reduce the NOx emission when the engine starts cold, and improve the SCR conversion efficiency at low temperature cold start.

In the second aspect, the embodiment of the present application provides an engine aftertreatment temperature control device, which is applied to the exhaust aftertreatment system. ccDOC system, close-coupled selective catalytic converter ccSCR system, selective catalytic converter SCR post-treatment system; the device includes:

The first thermal management module is configured to respond to the engine start command, determine that the engine water temperature is lower than a preset first temperature threshold, and execute a first thermal management operation; the first thermal management operation is used to enable the ccDOC system to proceed increase in air temperature;

The first fuel injection quantity control module is configured to, if it is detected that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, based on the target air outlet temperature of the ccDOC system, the intake air temperature and the exhaust gas The mass flow rate is obtained by the feed-forward control fuel injection quantity of the post-injection in the cylinder; the measured temperature of the gas outlet of the ccDOC system is used as the feedback value, based on the target temperature of the gas outlet of the ccDOC system, the intake air temperature and the feed-forward control The fuel injection quantity is obtained by the closed-loop control fuel injection quantity of the post-injection in the cylinder;

The second fuel injection quantity control module is used to obtain the target fuel injection quantity of post-injection in the cylinder based on the fuel injection calculation value and the preset fuel injection range threshold; the fuel injection calculation value is the same as the fuel injection quantity of the feedforward control The sum of the closed-loop control fuel injection quantities;

A post-injection execution control module, configured to perform an in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity, so as to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature.

In a possible implementation manner, the fuel injection range threshold includes a fuel injection upper limit; the second fuel injection quantity control module is specifically used for:

Obtain the fuel injection upper limit value of the engine;

If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, the fuel injection calculation value is used as the in-cylinder post-injection target fuel injection quantity;

If the fuel injection calculated value is greater than the fuel injection upper limit, the fuel injection upper limit is used as the in-cylinder post-injection target fuel injection amount.

In a possible implementation manner, the second fuel injection quantity control module is specifically used for:

Obtain the real-time rotational speed and real-time torque of the engine;

Based on the real-time rotational speed and the real-time torque query the preset fuel injection boundary MAP map to obtain the fuel injection upper limit value; the fuel injection boundary MAP map is the mapping relationship between engine speed and engine torque and fuel injection boundary value .

In a possible implementation manner, the first fuel injection quantity control module is specifically used for:

Obtain the target temperature of the outlet gas of the ccDOC system, and the conversion efficiency of hydrocarbons and HCs;

Obtaining the exhaust gas mass flow rate, the intake air temperature, fuel calorific value and exhaust thermal fusion value of the engine;

Taking the difference between the target air outlet temperature and the intake air temperature to obtain a temperature difference value;

multiplying the mass flow rate of the exhaust gas by the thermal melting value of the exhaust gas and the temperature difference value to obtain the demand for heat release;

The heat release demand, the fuel calorific value and the HC conversion efficiency are quotiented to obtain the feed-forward control fuel injection quantity of the in-cylinder rear injection.

In a possible implementation manner, the first fuel injection quantity control module is specifically used for:

Based on the intake air temperature and the exhaust gas mass flow rate, query a preset conversion rate MAP map to obtain the hydrocarbon HC conversion efficiency of the ccDOC system of the engine;

Wherein, the conversion rate MAP map is a mapping relationship between the intake temperature of the ccDOC system, the mass flow rate of exhaust gas of the engine, and the fuel conversion efficiency of the ccDOC system.

In a possible implementation manner, a cold start control exit module is also included for:

If it is detected that the engine water temperature is higher than the first temperature threshold, the first heat management operation and the in-cylinder post-injection operation are stopped.

In a possible implementation manner, the intake air temperature is obtained from a first temperature sensor at the front end of the ccDOC system; the actual outlet gas temperature is obtained from a second temperature sensor between the ccDOC system and the ccSCR system .

In a possible implementation manner, the first fuel injection quantity control module is specifically used for:

Obtain the measured temperature of the outlet gas of the ccDOC system;

Comparing the measured temperature of the outlet gas with the target temperature of the outlet gas;

According to the comparison result of the measured temperature of the outlet gas and the target temperature of the outlet gas, an adjustment amount for adjusting the fuel injection quantity of the feedforward control of the post-injection in the cylinder is determined as the closed-loop control fuel injection quantity of the post-injection in the cylinder.

In a third aspect, there is provided an electronic device, including a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor executes any one of the above The steps of the engine aftertreatment temperature control method.

In a fourth aspect, a computer-readable storage medium is provided, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the engine aftertreatment temperature control methods described above is implemented.

For the technical effect brought by any one of the implementation manners from the second aspect to the fourth aspect, please refer to the technical effect brought by the implementation manner in the first aspect, which will not be repeated here.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For Those skilled in the art can also obtain other drawings based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of an exhaust aftertreatment system provided in an embodiment of the present application;

Fig. 2 is a schematic flow chart of a method for controlling engine aftertreatment temperature provided by an embodiment of the present application;

Fig. 3 is a schematic flow chart of determining feed-forward control fuel injection quantity in an engine aftertreatment temperature control method provided by an embodiment of the present application;

Fig. 4 is a schematic flow chart of determining the closed-loop control fuel injection quantity of an engine aftertreatment temperature control method provided by an embodiment of the present application;

Fig. 5 is a schematic flow chart of determining the target fuel injection quantity of post-injection in cylinder in a method for controlling the temperature of after-treatment of the engine provided by the embodiment of the present application;

FIG. 6 is a schematic structural diagram of an engine aftertreatment temperature control device provided in an embodiment of the present application;

Fig. 7 is a schematic structural diagram of another engine aftertreatment temperature control device provided by the embodiment of the present application;

FIG. 8 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Part of the terms used in the embodiments of the present application are explained below to facilitate the understanding of those skilled in the art.

(1) ECU (Electronic Control Unit, Electronic Control Unit): ECU, also known as "Engine Electronic Control Unit", is a controller that performs calculation, processing, and judgment based on signals input by various sensors, and then outputs instructions to control the action of the actuator .

(2) Bench: The bench is the test equipment for engine calibration, which is used to calibrate various performance parameters of the engine, including engine speed, engine torque, fuel injection volume and emission.

(3) ccSCR (close coupled selectively catalytic reduction, close coupled selective catalytic conversion device): ccSCR is a catalytic converter usually installed at the front end of the SCR aftertreatment system to make full use of the heat in the exhaust gas and reduce the urea injection stop time , to improve the NOx conversion efficiency of the aftertreatment system at low temperatures.

(4) SCR (selectively catalytic reduction, selective catalytic conversion device): SCR is a catalytic converter installed after ccSCR, which is a post-installed selective catalytic conversion device to reduce nitrogen oxide emissions from diesel engines an effective means. Usually urea solution with a concentration of 32.5% is injected into the exhaust pipe. The urea is decomposed at high temperature to generate regular ammonia gas, which reduces the NOx in the exhaust gas to nitrogen and water, thereby reducing NOx emissions.

(5) DPF (diesel particulate filter, particulate matter trap): used to capture particulate matter in the exhaust gas. When the quality of the captured particulate matter reaches a certain level, passive regeneration or active regeneration is required to restore the DPF’s capture of particulate matter. collection capacity.

(6) ccDOC (close coupled diesel oxide catalyst, close coupled oxidation catalytic converter): ccDOC is used to convert the NO in the exhaust gas into NO2 and assist the normal operation of ccSCR.

(7) DOC (diesel oxide catalyst, oxidation catalytic converter): The oxidation catalytic converter can be installed in front of the DPF to convert the NO in the exhaust gas into NO2, and at the same time increase the temperature of the exhaust gas to assist the normal operation of the DPF and SCR.

(8) ASC (Ammonia Slip Catalyst, Ammonia Oxidation Catalyst): ASC is a kind of exhaust gas post-treatment device for diesel vehicles. It is installed at the back end of SCR and reduces the leakage of ammonia from the exhaust gas at the back end of SCR through catalytic oxidation. device.

In order to improve the conversion efficiency of the SCR at low-temperature cold start, an embodiment of the present application provides a method, device, electronic equipment and medium for controlling the temperature of an engine aftertreatment. In order to better understand the technical solutions provided by the embodiments of the present application, here is a brief description of the basic principles of the solutions.

It should be noted that the terms "first" and "second" in the description and claims of the present application and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with aspects of the present application as recited in the appended claims.

The following describes the technical solutions provided by the embodiments of the present application with reference to the accompanying drawings.

Engines using the SCR after-treatment system need to inject urea into the SCR to react the NOx in the exhaust gas and generate non-toxic and non-polluting N ₂ and H ₂ O at the same time. As environmental protection requirements become more and more stringent, for example, environmental protection regulations in some regions require the detection of NOx emissions after 2 kilometers, so improving the SCR conversion efficiency at low temperature and cold start is very important to meet the current emission requirements.

At present, in the related art, the engine post-treatment during the cold start process is usually unable to effectively intervene, resulting in low conversion efficiency of the low-temperature cold start SCR in the prior art.

In view of this, the embodiments of the present application provide a method, device, electronic equipment and medium for controlling engine aftertreatment temperature, wherein the engine aftertreatment temperature control method is applied to an exhaust aftertreatment system, and the exhaust aftertreatment system includes exhaust The trachea is sequentially connected to the close-coupled oxidation catalytic converter ccDOC system at the engine exhaust outlet, the close-coupled selective catalytic conversion device ccSCR system, and the selective catalytic conversion device SCR after-treatment system; by responding to the engine start command, it is determined that the engine water temperature is low At the preset first temperature threshold, execute the first thermal management operation; the first thermal management operation is used to increase the intake air temperature of the ccDOC system; if it is detected that the intake air temperature of the ccDOC system rises to the preset second temperature The threshold value is based on the target temperature of the outlet gas of the ccDOC system, the intake air temperature and the mass flow rate of the exhaust gas to obtain the feed-forward control fuel injection quantity of the rear injection in the cylinder; the actual temperature of the outlet gas of the ccDOC system is used as the feedback value, and the target temperature of the outlet gas based on the ccDOC system , intake air temperature and feed-forward control fuel injection quantity, to obtain the closed-loop control fuel injection quantity of rear injection in the cylinder; based on the calculation value of fuel injection and the preset fuel injection range threshold, the target fuel injection quantity of rear injection in cylinder is obtained; fuel injection The calculated value is the sum of feed-forward control fuel injection volume and closed-loop control fuel injection volume; in-cylinder post-injection operation is performed based on the in-cylinder post-injection target fuel injection volume to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature. In this method, a ccDOC system and a ccSCR system are added behind the exhaust port of the engine, and the aftertreatment exhaust gas is thermally managed when the engine is cold-started, thereby increasing the aftertreatment temperature and reducing NOx emissions when the engine is cold-started, Improve low temperature cold start SCR conversion efficiency.

The preferred embodiments of the application will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the application, and are not used to limit the application, and in the absence of conflict, the application The embodiments in the embodiments and the features in the embodiments can be combined with each other.

Fig. 1 shows an exhaust aftertreatment system provided by an embodiment of the present application. As shown in FIG. 1 , the exhaust after-treatment system 100 includes a ccDOC system, a ccSCR system, and an SCR after-treatment system which are sequentially connected to the exhaust outlet of the engine through an exhaust pipe.

In some embodiments, a first temperature sensor is provided at the front end of the ccDOC system; a second temperature sensor is provided between the ccDOC system and the ccSCR system.

In some optional embodiments, the SCR aftertreatment system includes a DOC system, a DPF system, an SCR system, and an ASC system connected in sequence through an exhaust pipe.

In some other embodiments, the exhaust aftertreatment system 100 further includes:

The third temperature sensor and the fourth temperature sensor, the third temperature sensor is arranged at the outlet of the DOC system, and the fourth temperature sensor is arranged at the outlet of the ASC system.

The engine aftertreatment temperature control method applicable to the exhaust aftertreatment system 100 provided by the embodiment of the present application will be further explained below. As shown in Figure 2, it includes the following steps:

S201. In response to an engine start instruction, it is determined that the engine water temperature is lower than a preset first temperature threshold, and a first thermal management operation is performed.

Wherein, the first thermal management operation is used to increase the intake air temperature of the ccDOC system.

During specific implementation, the ECU of the vehicle may respond to the engine start command, determine that the engine water temperature is lower than the preset first temperature threshold, and execute the first thermal management operation, wherein the first thermal management operation is used to reduce the intake air temperature of the ccDOC system to promote.

Exemplarily, assuming that the first temperature threshold is Tem_St1, the ECU of the vehicle determines that the engine water temperature Tem_Wa is lower than the preset first temperature threshold Tem_St1 in response to the engine start command, and performs the first thermal management operation, wherein the first thermal management operation It is used to increase the intake air temperature T_cD_In of the ccDOC system.

In the embodiment of the present application, the value of the first temperature threshold Tem_St1 may be in the range of 38-42°C. For example, the first temperature threshold Tem_St1 may be set to 40°C.

S202, if it is detected that the intake air temperature of the ccDOC system rises to the preset second temperature threshold, based on the target air outlet temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection of the rear injection in the cylinder is obtained Quantity; taking the measured outlet temperature of the ccDOC system as the feedback value, based on the target outlet temperature of the ccDOC system, the intake air temperature and the feed-forward control fuel injection volume, the closed-loop control fuel injection volume of the post-injection in the cylinder is obtained.

During specific implementation, when the vehicle ECU monitors that the intake air temperature of the ccDOC system has risen to the preset second temperature threshold, based on the target outlet temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward of the rear injection in the cylinder is obtained The fuel injection quantity is controlled, and the measured temperature of the gas outlet of the ccDOC system is used as the feedback value, based on the target temperature of the gas outlet of the ccDOC system, the intake temperature and the fuel injection quantity of the feedforward control, and the closed-loop control fuel injection quantity of the rear injection in the cylinder is obtained.

The second temperature threshold of the present application may be set based on the fuel light-off temperature. In some embodiments, the second temperature threshold may be a fuel light-off temperature, for example, the second temperature threshold may be set to 280°C.

For example, if it is detected that the intake air temperature T_cD_In of the ccDOC system rises to the preset second temperature threshold Tem_St2, based on the target outlet temperature TTar_cD_Ou, intake air temperature T_cD_In and exhaust gas mass flow Mixt_m of the ccDOC system, the in-cylinder rear Feed-forward control fuel injection quantity Fuel_Ad; taking the actual measured temperature Treal_cD_Ou of the ccDOC system as the feedback value, based on the target temperature TTar_cD_Ou of the ccDOC system, the intake air temperature T_cD_In and the feed-forward control fuel injection quantity Fuel_Ad, the in-cylinder rear injection Closed loop control fuel injection quantity Fuel_cl.

In a possible implementation, in step S202, based on the target outlet temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity of the rear injection in the cylinder is obtained, as shown in Figure 3, which can be obtained by The following steps are implemented:

S301. Obtain the target gas outlet temperature and HC conversion efficiency of the ccDOC system.

During specific implementation, the vehicle ECU obtains the target gas outlet temperature TTar_cD_Ou of the ccDOC system, and the HC conversion efficiency HC_Perc.

In a possible implementation, the process of obtaining the conversion efficiency of hydrocarbons and HCs of the ccDOC system is specifically: based on the intake air temperature and the mass flow rate of exhaust gas, query the preset conversion rate MAP map to obtain the hydrocarbons and HCs of the ccDOC system of the engine HC conversion efficiency; among them, the conversion rate MAP map is the mapping relationship between the intake temperature of the ccDOC system and the mass flow rate of the engine exhaust gas and the fuel conversion efficiency of the ccDOC system.

In the embodiment of the present application, the conversion rate MAP map can be calibrated and obtained through an engine bench test.

S302. Obtain the exhaust gas mass flow rate, intake air temperature, fuel calorific value, and exhaust thermal fusion value of the engine.

Exemplarily, the vehicle ECU obtains the exhaust gas mass flow rate Mixt_m of the engine, the intake air temperature T_cD_In, the fuel calorific value Fuel_q and the exhaust thermal fusion value Mixt_c.

S303, taking a difference between the target outlet air temperature and the intake air temperature to obtain a temperature difference value.

Exemplarily, the vehicle ECU takes the difference between the target outlet temperature TTar_cD_Ou and the intake air temperature T_cD_In to obtain the temperature difference T_cD_Gap.

S304. Calculate the product of the mass flow rate of the exhaust gas, the thermal fusion value and the temperature difference value of the exhaust gas to obtain the heat release demand.

Exemplarily, the vehicle ECU multiplies the exhaust gas mass flow rate Mixt_m, the exhaust heat fusion value Mixt_c and the temperature difference value T_cD_Gap to obtain the heat release demand Q_re.

S305, calculate the quotient of heat release demand, fuel calorific value and HC conversion efficiency, and obtain the feed-forward control fuel injection quantity of post-injection in cylinder.

Exemplarily, the heat release requirement Q_re is calculated with the fuel calorific value Mixt_c and the HC conversion efficiency HC_Perc to obtain the feed-forward control fuel injection quantity Fuel_Ad of the in-cylinder post-injection. That is, the feed-forward control fuel injection quantity Fuel_Ad can be determined by the following formula:

Fuel_Ad=Q_re/(Mixt_c·HC_Perc),

Among them, Fuel_Ad represents the feed-forward control fuel injection quantity of post-injection in cylinder,

Q_re represents the heat release demand,

Mixt_c represents the calorific value of the fuel,

HC_Perc represents HC conversion efficiency.

In a possible implementation, in step S202, the closed-loop after-injection in-cylinder is obtained based on the target air outlet temperature of the ccDOC system, the intake air temperature, and the feed-forward control injection quantity based on the actual temperature of the air outlet of the ccDOC system as the feedback value in step S202. The process of controlling the fuel injection quantity, as shown in Figure 4, may include the following steps:

S401. Obtain the measured temperature of the outlet gas of the ccDOC system.

Exemplarily, the vehicle ECU acquires the actual measured temperature Treal_cD_Ou of the outlet gas of the ccDOC system.

S402. Comparing the measured temperature of the outlet gas with the target temperature of the outlet gas.

In some embodiments of the present application, the target temperature of the outlet gas may be set to 350°C. Setting the outlet gas target temperature to this temperature can reduce the NOx emission of the engine during cold start and improve the SCR conversion efficiency at low temperature cold start.

In some other embodiments of the present application, the outlet gas target temperature may also be obtained by querying a pre-calibrated target temperature MAP map based on the intake air temperature and exhaust gas volume flow rate of the ccDOC system. Among them, the target temperature MAP map is the mapping relationship between the intake temperature of the engine ccDOC system, the volume flow rate of the engine exhaust gas, and the target temperature at the outlet of the ccDOC system. Wherein, the exhaust gas volume flow rate may be converted by the vehicle ECU based on the exhaust gas mass flow rate.

The target temperature MAP map is a specific data of the engine ccDOC system intake temperature on the X axis, the engine exhaust gas volume flow on the Y axis, and the target temperature at the outlet of the ccDOC system on the Z axis. Therefore, as long as there is data on the intake air temperature and exhaust gas volume flow of the ccDOC system, the target temperature MAP map can be checked to obtain the current target temperature at the outlet of the ccDOC system.

Exemplarily, the vehicle ECU compares the actual measured temperature of the outlet gas Treal_cD_Ou with the target temperature of the outlet gas TTar_cD_Ou to obtain a comparison result of the outlet gas temperature T_cD_Ou_Gap.

S403. According to the comparison result of the actual measured temperature of the outlet gas and the target temperature of the outlet gas, an adjustment amount for adjusting the feed-forward control fuel injection amount of the in-cylinder rear injection is determined as the closed-loop control fuel injection amount of the in-cylinder rear injection.

Exemplarily, the ECU of the vehicle determines the adjustment amount for adjusting the feed-forward control fuel injection quantity of the post-injection in cylinder according to the comparison result T_cD_Ou_Gap of the actual measured temperature of the outlet gas and the target temperature of the outlet gas, as the closed-loop control fuel injection quantity of the in-cylinder post-injection Fuel_cl.

S203. Based on the fuel injection calculation value and the preset fuel injection range threshold, the target fuel injection quantity of the post-injection in the cylinder is obtained; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity.

During specific implementation, the fuel injection range threshold may be preset in the vehicle ECU. The ECU of the vehicle obtains the target fuel injection quantity of the post-injection in the cylinder based on the fuel injection calculation value and the preset fuel injection range threshold; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity.

Exemplarily, the vehicle ECU obtains the target fuel injection quantity Fuel_Tar of post-injection in the cylinder based on the fuel injection calculation value Fuel_Ad_math and the preset fuel injection range threshold Fuel_St; The amount of oil Fuel_cl and.

In some embodiments of the present application, the fuel injection calculation value of the in-cylinder post-injection calculated by the feed-forward control fuel injection quantity plus the closed-loop control fuel injection quantity and the fuel injection boundary are taken to be smaller to obtain the final in-cylinder post-injection target fuel injection quantity. Wherein, the fuel injection boundary may be a fuel injection upper limit value.

In a possible implementation, the fuel injection range threshold includes the fuel injection upper limit value; based on the fuel injection calculation value and the preset fuel injection range threshold, the target fuel injection quantity of the post-injection in the cylinder is obtained, as shown in Figure 5, Include the following steps:

S501. Obtain the fuel injection upper limit value of the engine.

In a possible implementation manner, obtaining the fuel injection upper limit value of the engine includes the following steps:

Step A01, acquiring the real-time rotational speed and real-time torque of the engine.

Step A02, querying the preset fuel injection boundary MAP based on the real-time speed and real-time torque to obtain the fuel injection upper limit value; the fuel injection boundary MAP is a mapping relationship between the engine speed and engine torque and the fuel injection boundary value.

S502. If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, use the fuel injection calculation value as the target fuel injection quantity of the post-injection in the cylinder.

S503. If the fuel injection calculation value is greater than the fuel injection upper limit value, the fuel injection upper limit value is used as the target fuel injection quantity of the post-injection in the cylinder.

S204 , performing an in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity, so as to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature.

Exemplarily, the vehicle ECU performs an in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection amount Fuel_Tar, so as to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature TTar_cD_Ou.

In some embodiments of the engine aftertreatment temperature control method of the present application, after step S204, when it is detected that the engine water temperature is higher than the first temperature threshold, the above-mentioned first thermal management operation and the above-mentioned in-cylinder post-injection operation may be stopped .

In a possible implementation manner, the method further includes: if it is detected that the engine water temperature is higher than the first temperature threshold, stopping the first thermal management operation and the in-cylinder post-injection operation.

In a possible implementation manner, the intake air temperature is obtained from the first temperature sensor at the front end of the ccDOC system; the actual outlet temperature is obtained from the second temperature sensor between the ccDOC system and the ccSCR system.

The engine aftertreatment temperature control method of the above embodiment is applied to the exhaust aftertreatment system. The exhaust aftertreatment system includes a close-coupled oxidation catalytic converter ccDOC system connected to the engine exhaust outlet through an exhaust pipe in sequence, a close-coupled selectivity Catalytic conversion device ccSCR system, selective catalytic conversion device SCR aftertreatment system; by responding to the engine start command, it is determined that the engine water temperature is lower than the preset first temperature threshold, and the first thermal management operation is performed; the first thermal management operation is used for Increase the intake air temperature of the ccDOC system; if it is detected that the intake air temperature of the ccDOC system rises to the preset second temperature threshold, based on the target outlet temperature of the ccDOC system, the intake air temperature and the mass flow rate of the exhaust gas, the in-cylinder rear Injection feed-forward control of fuel injection volume; taking the actual temperature of the ccDOC system’s outlet air as the feedback value, based on the ccDOC system’s target air outlet temperature, intake air temperature and feed-forward control of the fuel injection volume, the closed-loop control fuel injection volume of the post-injection in the cylinder is obtained ;Based on the fuel injection calculation value and the preset fuel injection range threshold, the target fuel injection volume of the post-injection in the cylinder is obtained; the fuel injection calculation value is the sum of the feed-forward control fuel injection volume and the closed-loop control fuel injection volume; The target fuel injection quantity is used to perform in-cylinder post-injection operation to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature. In this method, a ccDOC system and a ccSCR system are added behind the exhaust port of the engine, and the aftertreatment exhaust gas is thermally managed when the engine is cold-started, thereby increasing the aftertreatment temperature and reducing NOx emissions when the engine is cold-started, Improve low temperature cold start SCR conversion efficiency.

Based on the same inventive concept, the embodiment of the present application also provides an engine aftertreatment temperature control device, which is applied to the exhaust aftertreatment system. Catalytic converter ccDOC system, close-coupled selective catalytic converter ccSCR system, selective catalytic converter SCR aftertreatment system. As shown in Figure 6, the device includes:

The first thermal management module 601 is configured to respond to the engine start command, determine that the engine water temperature is lower than the preset first temperature threshold, and execute the first thermal management operation; the first thermal management operation is used to increase the intake air temperature of the ccDOC system ;

The first fuel injection quantity control module 602 is used to obtain the cylinder temperature based on the target temperature of the outlet gas of the ccDOC system, the intake air temperature and the mass flow rate of the exhaust gas if it is detected that the intake air temperature of the ccDOC system has risen to the preset second temperature threshold. Feedforward control of fuel injection quantity for internal and rear injection; taking the actual temperature of the outlet gas of the ccDOC system as the feedback value, based on the target temperature of the outlet gas of the ccDOC system, the intake air temperature and the fuel injection quantity of feedforward control, the closed-loop control injection quantity of the rear injection in the cylinder is obtained. oil quantity;

The second fuel injection quantity control module 603 is used to obtain the target fuel injection quantity of post-injection in the cylinder based on the fuel injection calculation value and the preset fuel injection range threshold; the fuel injection calculation value is feedforward control fuel injection quantity and closed-loop control injection sum of oil quantity;

The post-injection execution control module 604 is configured to perform an in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity, so as to adjust the outlet air temperature of the ccDOC system to the outlet air target temperature.

In a possible implementation manner, the fuel injection range threshold includes a fuel injection upper limit value; the second fuel injection quantity control module 603 is specifically used for:

Obtain the fuel injection upper limit of the engine;

If the calculation value of fuel injection is less than or equal to the upper limit value of fuel injection, the calculation value of fuel injection will be used as the target fuel injection quantity of post-injection in the cylinder;

If the calculated value of fuel injection is greater than the upper limit of fuel injection, the upper limit of fuel injection is used as the target fuel injection quantity of the post-injection in the cylinder.

In a possible implementation manner, the second fuel injection quantity control module 603 is specifically used for:

Obtain the real-time rotational speed and real-time torque of the engine;

Based on the real-time speed and real-time torque, query the preset fuel injection boundary MAP map to obtain the fuel injection limit value; the fuel injection boundary MAP map is the mapping relationship between the engine speed and engine torque and the fuel injection boundary value.

In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

Obtain the target temperature of the outlet gas of the ccDOC system and the conversion efficiency of hydrocarbons and HCs;

Obtain the exhaust gas mass flow rate, intake air temperature, fuel calorific value and exhaust thermal fusion value of the engine;

Take the difference between the target temperature of the outlet gas and the temperature of the intake air to obtain the temperature difference value;

Calculate the product of the exhaust gas mass flow rate, the exhaust thermal melting value and the temperature difference value to obtain the heat release demand;

Quotient the heat release demand with the fuel calorific value and HC conversion efficiency to obtain the feedforward control fuel injection quantity of the rear injection in the cylinder.

In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

Based on the intake air temperature and exhaust gas mass flow rate, query the preset conversion rate MAP map to obtain the hydrocarbon HC conversion efficiency of the engine's ccDOC system;

Among them, the conversion rate MAP map is the mapping relationship between the intake temperature of the ccDOC system, the mass flow rate of the engine exhaust gas and the fuel conversion efficiency of the ccDOC system.

In a possible implementation, as shown in FIG. 7, the device further includes a cold start control exit module 701, and the cold start control exit module 701 is used for:

If it is detected that the engine water temperature is higher than the first temperature threshold, the first thermal management operation and the post-injection operation in the cylinder are stopped.

In a possible implementation manner, the intake air temperature is obtained from the first temperature sensor at the front end of the ccDOC system; the actual outlet temperature is obtained from the second temperature sensor between the ccDOC system and the ccSCR system.

In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

Obtain the measured temperature of the outlet gas of the ccDOC system;

Compare the measured temperature of the outlet gas with the target temperature of the outlet gas;

According to the comparison result of the measured temperature of the outlet gas and the target temperature of the outlet gas, the adjustment amount for adjusting the fuel injection quantity of the feedforward control of the post-injection in the cylinder is determined as the closed-loop control fuel injection quantity of the post-injection in the cylinder.

Based on the same technical concept, the embodiment of the present application also provides an electronic device, as shown in FIG. A memory 801, a processor 802, an input unit 803, and a display panel 804 may be included.

The memory 801 is used for storing computer programs executed by the processor 802 . The memory 801 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one function, etc.; the data storage area may store data created according to the use of the electronic device, etc. The processor 802 may be a central processing unit (central processing unit, CPU), or a digital processing unit or the like. The input unit 803 may be used to obtain user instructions input by the user. The display panel 804 is used to display information input by the user or information provided to the user. In the embodiment of the present application, the display panel 804 is mainly used to display the display interface of each application program in the terminal device and the control entities displayed in each display interface . Optionally, the display panel 804 may be configured in the form of a liquid crystal display (liquid crystal display, LCD) or an OLED (organic light-emitting diode, organic light-emitting diode).

In this embodiment of the present application, a specific connection medium among the memory 801, the processor 802, the input unit 803, and the display panel 804 is not limited. In the embodiment of the present application, in FIG. 8, the memory 801, the processor 802, the input unit 803, and the display panel 804 are connected through a bus 805. The bus 805 is represented by a thick line in FIG. It is for illustrative purposes only, and is not intended to be limiting. The bus 805 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is used in FIG. 8 , but it does not mean that there is only one bus or one type of bus.

The memory 801 can be a volatile memory (volatile memory), such as a random-access memory (random-access memory, RAM); the memory 801 can also be a non-volatile memory (non-volatile memory), such as a read-only memory, a flash memory (flash memory), hard disk (hard disk drive, HDD) or solid-state drive (solid-state drive, SSD), or the memory 801 can be used to carry or store desired program codes in the form of instructions or data structures and can be used by the computer Any other medium accessed, but not limited to. The memory 801 may be a combination of the above-mentioned memories.

The processor 802 is configured to call a computer program stored in the memory 801 to execute the above-mentioned embodiments, for example, implement the steps of the method shown in FIG. 2 .

The embodiment of the present application also provides a computer-readable storage medium, which stores computer-executable instructions for executing the above-mentioned processor, and includes a program for executing the above-mentioned processor.

In some possible implementations, various aspects of the engine aftertreatment temperature control method provided in this application can also be implemented in the form of a program product, which includes program codes. When the program product runs on the terminal device, the program The codes are used to make the terminal device execute the steps in the method for controlling the temperature of an engine aftertreatment according to various exemplary embodiments of the present application described above in this specification. For example, an electronic device may implement the embodiment shown in FIG. 2 .

A program product may take the form of any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: electrical connection with one or more conductors, portable disk, hard disk, random access memory (RAM), read only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

The program product for an engine aftertreatment temperature control according to an embodiment of the present application may adopt a portable compact disk read only memory (CD-ROM) and include program codes, and may run on a computing device. However, the program product of the present application is not limited thereto. In this document, a readable storage medium may be any tangible medium containing or storing a program, and the program may be used by or in combination with an instruction execution system, device, or device.

A readable signal medium may include a data signal carrying readable program code in baseband or as part of a carrier wave. Such propagated data signals may take many forms, including - but not limited to - electromagnetic signals, optical signals, or any suitable combination of the foregoing. A readable signal medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

Program code embodied on a readable medium may be transmitted using any appropriate medium, including - but not limited to - wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program codes for performing the operations of this application may be written in any combination of one or more programming languages, including entity-oriented programming languages such as Java, C++, etc., and conventional procedural programming Language - such as "C" or similar programming language. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server to execute. In cases involving a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a local area network (LAN) or a wide area network (WAN), or, alternatively, may be connected to an external computing device (e.g., using an Internet service Provider via Internet connection).

It should be noted that although several units or subunits of the apparatus are mentioned in the above detailed description, this division is only exemplary and not mandatory. Actually, according to the embodiment of the present application, the features and functions of two or more units described above may be embodied in one unit. Conversely, the features and functions of one unit described above may be further divided to be embodied by a plurality of units.

In addition, while operations of the methods of the present application are depicted in the figures in a particular order, there is no requirement or implication that these operations must be performed in that particular order, or that all illustrated operations must be performed to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and/or one step may be decomposed into multiple steps for execution.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable document processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable document processing device produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable document processing device to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable document processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, whereby the The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

While preferred embodiments of the present application have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, the appended claims are intended to be construed to cover the preferred embodiment and all changes and modifications which fall within the scope of the application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (11)

1. The engine aftertreatment temperature control method is characterized by being applied to an exhaust aftertreatment system, wherein the exhaust aftertreatment system comprises a close-coupled oxidation catalytic converter (CCDOC) system, a close-coupled selective catalytic conversion device (ccSCR) system and a selective catalytic conversion device (SCR) aftertreatment system which are sequentially communicated with an engine tail gas outlet through an exhaust pipe; the method comprises the following steps:

in response to an engine start command, determining that an engine water temperature is below a preset first temperature threshold, performing a first thermal management operation; the first thermal management operation is to raise an intake air temperature of the ccDOC system;

if the temperature of the air inlet of the ccDOC system is monitored to rise to a preset second temperature threshold value, based on the target air outlet temperature of the ccDOC system, the air inlet temperature and the exhaust gas mass flow, the feedforward control fuel injection quantity of in-cylinder post-injection is obtained; taking the actually measured temperature of the outlet gas of the ccDOC system as a feedback value, and obtaining the closed-loop control fuel injection quantity of in-cylinder post-injection based on the target outlet gas temperature, the inlet gas temperature and the feedforward control fuel injection quantity of the ccDOC system;

Based on the oil injection accounting value and a preset oil injection range threshold value, obtaining in-cylinder post-injection target oil injection quantity; the oil injection accounting value is the sum of the feedforward control oil injection quantity and the closed-loop control oil injection quantity;

and performing in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection amount to adjust the outlet gas temperature of the ccDOC system to the outlet gas target temperature.

2. The method of claim 1, wherein the injection range threshold comprises an injection upper limit; the method for obtaining the post-injection target injection quantity in the cylinder based on the injection accounting value and the preset injection range threshold value comprises the following steps:

acquiring an oil injection upper limit value of the engine;

if the oil injection accounting value is smaller than or equal to the oil injection upper limit value, the oil injection accounting value is used as the in-cylinder post-injection target oil injection quantity;

and if the oil injection verification value is larger than the oil injection upper limit value, taking the oil injection upper limit value as the post-injection target oil injection quantity in the cylinder.

3. The method of claim 2, wherein the obtaining the upper limit value of injection of the engine comprises:

acquiring the real-time rotating speed and the real-time torque of the engine;

inquiring a preset fuel injection boundary MAP graph based on the real-time rotating speed and the real-time torque to obtain the fuel injection upper limit value; the fuel injection boundary MAP is a mapping relation between the engine speed and the engine torque and the fuel injection boundary value.

4. The method of claim 1, wherein the deriving the feed-forward control injection quantity of the in-cylinder post-injection based on the outlet target temperature, the inlet temperature, and the exhaust gas mass flow of the ccDOC system comprises:

acquiring the target temperature of the air outlet of the ccDOC system and the hydrocarbon HC conversion efficiency;

acquiring the exhaust gas mass flow, the intake air temperature, the fuel heating value and the exhaust gas hot melt value of the engine;

taking a difference value between the air outlet target temperature and the air inlet temperature to obtain a temperature difference value;

multiplying the exhaust gas mass flow by the exhaust gas hot melt value and the temperature difference value to obtain an exothermic demand;

and obtaining the quotient of the heat release demand quantity, the fuel calorific value and the HC conversion efficiency, and obtaining the feed-forward control fuel injection quantity of in-cylinder post injection.

5. The method of claim 4, wherein the obtaining the hydrocarbon HC conversion efficiency of the ccDOC system comprises:

inquiring a preset conversion rate MAP graph based on the air inlet temperature and the exhaust gas mass flow to obtain the hydrocarbon HC conversion efficiency of the ccDOC system of the engine;

the conversion rate MAP is a mapping relation between the inlet air temperature of the ccDOC system and the mass flow of the engine exhaust gas and the fuel conversion efficiency of the ccDOC system.

6. The method according to claim 1, wherein the method further comprises:

and if the detected water temperature of the engine is higher than the first temperature threshold value, stopping the first thermal management operation and the in-cylinder post-injection operation.

7. The method of claim 1, wherein the intake air temperature is obtained from a first temperature sensor at a front end of the ccDOC system; the measured temperature of the outlet gas is obtained from a second temperature sensor between the ccDOC system and the ccSCR system.

8. The method of claim 1, wherein the obtaining the closed-loop control injection amount of the post-cylinder injection based on the target temperature of the outlet gas of the ccDOC system, the inlet gas temperature, and the feed-forward control injection amount with the measured outlet gas temperature of the ccDOC system as a feedback value includes:

obtaining the actually measured temperature of the outlet gas of the ccDOC system;

comparing the measured temperature of the vent gas with the target temperature of the vent gas;

and determining the adjustment quantity for adjusting the feed-forward control fuel injection quantity of the in-cylinder post-injection according to the comparison result of the actually-measured temperature of the air outlet and the target temperature of the air outlet, and taking the adjustment quantity as the closed-loop control fuel injection quantity of the in-cylinder post-injection.

9. The engine aftertreatment temperature control device is characterized by being applied to an exhaust aftertreatment system, wherein the exhaust aftertreatment system comprises a close-coupled oxidation catalytic converter (ccDOC) system, a close-coupled selective catalytic conversion device (ccSCR) system and a selective catalytic conversion device (SCR) aftertreatment system which are sequentially communicated with an engine tail gas outlet through an exhaust pipe; the device comprises:

the first thermal management module is used for responding to an engine starting instruction, determining that the water temperature of the engine is lower than a preset first temperature threshold value and executing first thermal management operation; the first thermal management operation is to raise an intake air temperature of the ccDOC system;

the first fuel injection quantity control module is used for obtaining feedforward control fuel injection quantity of in-cylinder post-injection based on the target temperature of air outlet of the ccDOC system, the air inlet temperature and the mass flow of exhaust gas if the air inlet temperature of the ccDOC system is monitored to rise to a preset second temperature threshold; taking the actually measured temperature of the outlet gas of the ccDOC system as a feedback value, and obtaining the closed-loop control fuel injection quantity of in-cylinder post-injection based on the target outlet gas temperature, the inlet gas temperature and the feedforward control fuel injection quantity of the ccDOC system;

The second fuel injection quantity control module is used for obtaining in-cylinder post-injection target fuel injection quantity based on the fuel injection accounting value and a preset fuel injection range threshold value; the oil injection accounting value is the sum of the feedforward control oil injection quantity and the closed-loop control oil injection quantity;

and the post-injection execution control module is used for performing in-cylinder post-injection operation based on the in-cylinder post-injection target oil injection quantity so as to adjust the air outlet temperature of the ccDOC system to the air outlet target temperature.

10. An electronic device comprising a processor and a memory, wherein the memory stores program code that, when executed by the processor, causes the processor to perform the steps of the method of any of claims 1-8.

11. A computer-readable storage medium having a computer program stored therein, characterized in that: the computer program, when executed by a processor, implements the method of any of claims 1-8.

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