An engine aftertreatment temperature control method, device, electronic device and medium

Abstract

The present application discloses a method, device, electronic device and medium for controlling the temperature of engine aftertreatment. In the method, in response to an 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 executed; if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature, intake air temperature and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity for in-cylinder post-injection is obtained; taking the measured outlet temperature of the ccDOC system as the feedback value, based on the outlet target temperature, intake air temperature and feedforward control fuel injection quantity of the ccDOC system, the closed-loop control fuel injection quantity for in-cylinder post-injection is obtained; based on the fuel injection calculation value and a preset fuel injection range threshold, the target fuel injection quantity for in-cylinder post-injection is obtained; an in-cylinder post-injection operation is performed based on the target fuel injection quantity for in-cylinder post-injection to adjust the outlet temperature of the ccDOC system to the outlet target temperature.

Description

Technical Field

[0001] The present application relates to the field of automotive electronics technology, and particularly to an engine after-treatment temperature control method, device, electronic device, and medium. Background Art

[0002] For an engine using an SCR after-treatment system, it is necessary to inject urea into the SCR to react with NOx in the exhaust gas, and at the same time generate non-toxic and pollution-free N2 and H2O. With the increasingly strict environmental protection requirements, for example, some regional environmental protection regulations require the detection of NOx emissions after 2 kilometers. Therefore, improving the SCR conversion efficiency during low-temperature cold start is crucial for meeting the current emission requirements.

[0003] Currently, in the related art, the engine after-treatment during the cold start process usually cannot be effectively intervened, resulting in a low SCR conversion efficiency during low-temperature cold start in the prior art. Summary of the Invention

[0004] The embodiments of the present application provide an engine after-treatment temperature control method, device, electronic device, and medium, which can improve the SCR conversion efficiency during low-temperature cold start.

[0005] In a first aspect, the embodiments of the present application provide an engine after-treatment temperature control method, which is applied to an exhaust after-treatment system. The exhaust after-treatment system includes a close-coupled diesel oxidation catalyst (ccDOC) system, a close-coupled selective catalytic reduction (ccSCR) system, and a selective catalytic reduction (SCR) after-treatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet. The method includes:

[0006] In response to an engine start command, when it is determined that the engine water temperature is lower than a preset first temperature threshold, a first thermal management operation is performed; the first thermal management operation is used to increase the intake air temperature of the ccDOC system.

[0007] If it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature of the ccDOC system, the intake air temperature, and the exhaust gas mass flow rate, a feedforward control fuel injection amount for in-cylinder post-injection is obtained; using the measured outlet temperature of the ccDOC system as a feedback value, based on the outlet target temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection amount, a closed-loop control fuel injection amount for in-cylinder post-injection is obtained.

[0008] Based on the fuel injection calculation value and a preset fuel injection range threshold, an in-cylinder post-injection target fuel injection amount is obtained; the fuel injection calculation value is the sum of the feedforward control fuel injection amount and the closed-loop control fuel injection amount.

[0009] Perform in-cylinder post-injection operation based on the target in-cylinder post-injection fuel quantity to adjust the outlet gas temperature of the ccDOC system to the target outlet gas temperature.

[0010] The above method is applied to an exhaust aftertreatment system, which includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR aftertreatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet. By responding to an 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 gas temperature of the ccDOC system. If it is monitored that the intake gas temperature of the ccDOC system rises to a preset second temperature threshold, then based on the target outlet gas temperature of the ccDOC system, the intake gas temperature, and the exhaust gas mass flow rate, a feedforward control fuel quantity for in-cylinder post-injection is obtained. Using the measured outlet gas temperature of the ccDOC system as a feedback value, based on the target outlet gas temperature of the ccDOC system, the intake gas temperature, and the feedforward control fuel quantity, a closed-loop control fuel quantity for in-cylinder post-injection is obtained. Based on the fuel injection calculation value and a preset fuel injection range threshold, a target in-cylinder post-injection fuel quantity is obtained. The fuel injection calculation value is the sum of the feedforward control fuel quantity and the closed-loop control fuel quantity. Perform in-cylinder post-injection operation based on the target in-cylinder post-injection fuel quantity to adjust the outlet gas temperature of the ccDOC system to the target outlet gas temperature. This method adds a ccDOC system and a ccSCR system after the engine exhaust port and performs thermal management on the post-treatment exhaust during engine cold start, thereby increasing the post-treatment temperature, reducing NOx emissions during engine cold start, and improving the SCR conversion efficiency during low-temperature cold start.

[0011] In a possible implementation, the fuel injection range threshold includes a fuel injection upper limit value. The obtaining of the target in-cylinder post-injection fuel quantity based on the fuel injection calculation value and the preset fuel injection range threshold includes:

[0012] Obtain the fuel injection upper limit value of the engine;

[0013] If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, then use the fuel injection calculation value as the target in-cylinder post-injection fuel quantity;

[0014] If the fuel injection calculation value is greater than the fuel injection upper limit value, then use the fuel injection upper limit value as the target in-cylinder post-injection fuel quantity.

[0015] The above method can more quickly and efficiently prevent the post-injection fuel quantity in the cylinder from being too high by determining the post-injection target fuel quantity in the cylinder according to the preset upper limit value of fuel injection, achieving stable emissions based on the upper limit value of fuel injection, limiting the generation amount of NOx during cold start of the engine, and improving the SCR conversion efficiency during low-temperature cold start.

[0016] In a possible implementation manner, the obtaining of the upper limit value of fuel injection of the engine includes:

[0017] Obtain the real-time rotational speed and real-time torque of the engine;

[0018] Query a preset fuel injection boundary MAP diagram based on the real-time rotational speed and the real-time torque to obtain the upper limit value of fuel injection; the fuel injection boundary MAP diagram is a mapping relationship between the engine rotational speed, the engine torque, and the fuel injection boundary value.

[0019] The above method can obtain the real-time rotational speed and real-time torque of the engine; query a preset fuel injection boundary MAP diagram based on the real-time rotational speed and the real-time torque to obtain the upper limit value of fuel injection; the fuel injection boundary MAP diagram is a mapping relationship between the engine rotational speed, the engine torque, and the fuel injection boundary value. By determining the upper limit value of fuel injection corresponding to the real-time rotational speed and real-time torque of the engine according to the preset mapping relationship between the engine rotational speed, the engine torque, and the fuel injection boundary value, the upper limit value of fuel injection can be determined more quickly and efficiently, and the post-injection fuel quantity in the cylinder can be prevented from being too high more quickly and efficiently, realizing stable emissions based on the upper limit value of fuel injection, thereby limiting the generation amount of NOx during cold start of the engine and improving the SCR conversion efficiency during low-temperature cold start.

[0020] In a possible implementation manner, the obtaining of the feedforward control fuel quantity of post-injection in the cylinder based on the outlet target temperature of the ccDOC system, the intake temperature, and the exhaust gas mass flow rate includes:

[0021] Obtain the outlet target temperature of the ccDOC system and the hydrocarbon (HC) conversion efficiency;

[0022] Obtain the exhaust gas mass flow rate, the intake temperature, the fuel calorific value, and the exhaust heat capacity value of the engine;

[0023] Take the difference between the outlet target temperature and the intake temperature to obtain a temperature difference value;

[0024] Multiply the exhaust gas mass flow rate by the exhaust heat capacity value and the temperature difference value to obtain a heat release demand;

[0025] Divide the heat release demand by the fuel calorific value and the HC conversion efficiency to obtain the feedforward control fuel quantity of post-injection in the cylinder.

[0026] In the above method, the temperature difference value is obtained by taking the difference between the target outlet temperature and the inlet temperature, and then the heat release demand is obtained by multiplying the exhaust gas mass flow rate by the exhaust heat capacity value and the temperature difference value. Then, based on the heat release demand, the fuel calorific value, and the HC conversion efficiency, the feedforward control injection quantity of the post-injection in the cylinder is determined. This method adjusts the feedforward control injection quantity of the post-injection in the cylinder by combining the exhaust heat capacity value, the fuel calorific value, and the HC conversion efficiency, which can not only increase the aftertreatment temperature, reduce the NOx emissions during cold engine start, but also enhance the control accuracy of the post-injection quantity in the cylinder, and further improve the SCR conversion efficiency during low-temperature cold start.

[0027] In one possible implementation, obtaining the hydrocarbon (HC) conversion efficiency of the ccDOC system includes:

[0028] Based on the inlet temperature and the exhaust gas mass flow rate, query the preset conversion rate MAP graph to obtain the hydrocarbon (HC) conversion efficiency of the ccDOC system of the engine;

[0029] Wherein, the conversion rate MAP graph is the mapping relationship between the inlet temperature of the ccDOC system, the exhaust gas mass flow rate of the engine, and the fuel conversion efficiency of the ccDOC system.

[0030] In the above method, based on the inlet temperature and the exhaust gas mass flow rate, query the preset conversion rate MAP graph to obtain the hydrocarbon (HC) conversion efficiency of the ccDOC system of the engine; wherein, the conversion rate MAP graph is the mapping relationship between the inlet temperature of the ccDOC system, the exhaust gas mass flow rate of the engine, and the fuel conversion efficiency of the ccDOC system. This method can more quickly and efficiently determine the hydrocarbon (HC) conversion efficiency of the ccDOC system by determining the hydrocarbon (HC) conversion efficiency of the ccDOC system corresponding to the inlet temperature and the exhaust gas mass flow rate according to the mapping relationship between the inlet temperature of the ccDOC system, the exhaust gas mass flow rate of the engine, and the fuel conversion efficiency of the ccDOC system, can more accurately and efficiently determine the feedforward control injection quantity, and can not only increase the aftertreatment temperature, reduce the NOx emissions during cold engine start, but also enhance the control accuracy of the post-injection quantity in the cylinder, improve the real-time performance of the aftertreatment temperature control of the engine during cold start, and further improve the SCR conversion efficiency during low-temperature cold start.

[0031] In one possible implementation, the method further includes:

[0032] If it is monitored that the engine water temperature is higher than the first temperature threshold, stop the first thermal management operation and the post-injection operation in the cylinder.

[0033] 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. 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 continuous control of the engine after-treatment temperature during the cold start process can be achieved based on the engine water temperature. It is simple and easy to implement, reduces the calculation amount during the engine after-treatment temperature control, can effectively increase the after-treatment temperature during the cold start process, can reduce the NOx emissions when the engine is cold-started, and improves the SCR conversion efficiency during low-temperature cold start.

[0034] 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 measured outlet air temperature is obtained from a second temperature sensor between the ccDOC system and the ccSCR system.

[0035] In a possible implementation manner, taking the measured outlet air temperature of the ccDOC system as a feedback value, based on the target outlet air temperature of the ccDOC system, the intake air temperature, and the feedforward control injection quantity, obtaining the closed-loop control injection quantity for in-cylinder post-injection includes:

[0036] Obtain the measured outlet air temperature of the ccDOC system;

[0037] Compare the measured outlet air temperature with the target outlet air temperature;

[0038] According to the comparison result between the measured outlet air temperature and the target outlet air temperature, determine the adjustment amount for adjusting the feedforward control injection quantity for in-cylinder post-injection, and use it as the closed-loop control injection quantity for in-cylinder post-injection.

[0039] In the above method, obtain the measured outlet air temperature of the ccDOC system; compare the measured outlet air temperature with the target outlet air temperature; according to the comparison result between the measured outlet air temperature and the target outlet air temperature, determine the adjustment amount for adjusting the feedforward control injection quantity for in-cylinder post-injection, and use it as the closed-loop control injection quantity for in-cylinder post-injection. This method compares the measured outlet air temperature with the target outlet air temperature; according to the comparison result between the measured outlet air temperature and the target outlet air temperature, determine the adjustment amount for adjusting the feedforward control injection quantity for in-cylinder post-injection, so that continuous control of the engine after-treatment temperature during the cold start process can be achieved based on the measured outlet air temperature of the ccDOC system, improve the control accuracy and control efficiency when increasing the engine after-treatment temperature during the cold start process, effectively increase the after-treatment temperature during the cold start process, reduce the NOx emissions when the engine is cold-started, and improve the SCR conversion efficiency during low-temperature cold start.

[0040] Second aspect, an embodiment of the present application provides an engine after-treatment temperature control device, which is applied to an exhaust after-treatment system. The exhaust after-treatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR after-treatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet. The device includes:

[0041] A first thermal management module, configured to determine that the engine water temperature is lower than a preset first temperature threshold in response to an engine start command, and perform a first thermal management operation; the first thermal management operation is used to increase the intake air temperature of the ccDOC system.

[0042] A first fuel injection quantity control module, configured to, if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, obtain a feedforward control fuel injection quantity for post-injection in the cylinder based on the outlet target temperature of the ccDOC system, the intake air temperature, and the exhaust gas mass flow rate; using the measured outlet temperature of the ccDOC system as a feedback value, obtain a closed-loop control fuel injection quantity for post-injection in the cylinder based on the outlet target temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection quantity.

[0043] A second fuel injection quantity control module, configured to obtain a post-injection target fuel injection quantity in the cylinder based on an injection calculation value and a preset fuel injection range threshold; the injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity.

[0044] A post-injection execution control module, configured to perform a post-injection operation in the cylinder based on the post-injection target fuel injection quantity in the cylinder to adjust the outlet temperature of the ccDOC system to the outlet target temperature.

[0045] In a possible implementation manner, the fuel injection range threshold includes a fuel injection upper limit value; the second fuel injection quantity control module is specifically configured to:

[0046] Obtain the fuel injection upper limit value of the engine.

[0047] If the injection calculation value is less than or equal to the fuel injection upper limit value, use the injection calculation value as the post-injection target fuel injection quantity in the cylinder.

[0048] If the injection calculation value is greater than the fuel injection upper limit value, use the fuel injection upper limit value as the post-injection target fuel injection quantity in the cylinder.

[0049] In a possible implementation manner, the second fuel injection quantity control module is specifically configured to:

[0050] Obtain the real-time speed and real-time torque of the engine.

[0051] Query a preset injection boundary MAP based on the real-time rotational speed and the real-time torque to obtain the upper injection limit value; the injection boundary MAP is a mapping relationship between the engine speed, the engine torque, and the injection boundary value.

[0052] In a possible implementation manner, the first fuel injection quantity control module is specifically configured to:

[0053] Obtain the outlet target temperature of the ccDOC system and the hydrocarbon (HC) conversion efficiency;

[0054] Obtain the exhaust gas mass flow rate, the intake air temperature, the fuel calorific value, and the exhaust heat capacity of the engine;

[0055] Take the difference between the outlet target temperature and the intake air temperature to obtain a temperature difference value;

[0056] Multiply the exhaust gas mass flow rate by the exhaust heat capacity and the temperature difference value to obtain a heat release demand;

[0057] Divide the heat release demand by the fuel calorific value and the HC conversion efficiency to obtain the feedforward control fuel injection quantity for in-cylinder post-injection.

[0058] In a possible implementation manner, the first fuel injection quantity control module is specifically configured to:

[0059] Query a preset conversion rate MAP based on the intake air temperature and the exhaust gas mass flow rate to obtain the HC conversion efficiency of the ccDOC system of the engine;

[0060] Wherein, the conversion rate MAP is a mapping relationship between the intake air temperature of the ccDOC system, the engine exhaust gas mass flow rate, and the fuel conversion efficiency of the ccDOC system.

[0061] In a possible implementation manner, it further includes a cold start control exit module for:

[0062] If it is monitored that the engine water temperature is higher than the first temperature threshold, stop the first thermal management operation and the in-cylinder post-injection operation.

[0063] 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 measured outlet temperature is obtained from a second temperature sensor between the ccDOC system and the ccSCR system.

[0064] In a possible implementation manner, the first fuel injection quantity control module is specifically configured to:

[0065] Obtain the measured outlet temperature of the ccDOC system;

[0066] Compare the measured outlet temperature with the target outlet temperature;

[0067] According to the comparison result between the measured outlet temperature and the target outlet temperature, determine the adjustment amount for adjusting the feedforward control fuel injection quantity of the in-cylinder post-injection, and use it as the closed-loop control fuel injection quantity of the in-cylinder post-injection.

[0068] In a third aspect, an electronic device is provided, including a processor and a memory. Among them, the memory stores program codes, and when the program codes are executed by the processor, the processor is caused to execute the steps of the engine aftertreatment temperature control method in any one of the above.

[0069] In a fourth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the engine aftertreatment temperature control method in any one of the above is implemented.

[0070] For the technical effects brought by any implementation manner in the second aspect to the fourth aspect, reference may be made to the technical effects brought by the implementation manner in the first aspect, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for description in the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0072] Figure 1 It is a schematic structural diagram of an exhaust aftertreatment system provided by an embodiment of the present application;

[0073] Figure 2 It is a schematic flowchart of an engine aftertreatment temperature control method provided by an embodiment of the present application;

[0074] Figure 3 It is a schematic flowchart of determining the feedforward control fuel injection quantity of an engine aftertreatment temperature control method provided by an embodiment of the present application;

[0075] Figure 4 It is a schematic flowchart of determining the closed-loop control fuel injection quantity of an engine aftertreatment temperature control method provided by an embodiment of the present application;

[0076] Figure 5 It is a schematic flowchart of determining the target fuel injection quantity of in-cylinder post-injection of an engine aftertreatment temperature control method provided by an embodiment of the present application;

[0077] Figure 6Schematic structural diagram of an engine aftertreatment temperature control device provided by an embodiment of the present application;

[0078] Figure 7 Schematic structural diagram of another engine aftertreatment temperature control device provided by an embodiment of the present application;

[0079] Figure 8 Schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0080] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0081] The following explains some terms in the embodiments of the present application to facilitate the understanding of those skilled in the art.

[0082] (1) ECU (Electronic Control Unit): The ECU, also known as the "engine electronic control unit", is a controller that performs operations, processing, and judgments based on the signals input by various sensors, and then outputs instructions to control the actions of actuators.

[0083] (2) Test bench: The test bench is a test equipment for engine calibration, used to calibrate various performance parameters of the engine, including engine speed, engine torque, fuel injection quantity, and emissions, etc.

[0084] (3) ccSCR (close coupled selectively catalytic reduction): The 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, reduce the urea injection stop time, and improve the NOx conversion efficiency of the aftertreatment system at low temperatures.

[0085] (4) SCR (selectively catalytic reduction): The SCR is a catalytic converter installed after the ccSCR, which is a post-mounted selectively catalytic reduction device and an effective means to reduce diesel engine nitrogen oxide emissions by using the selective catalytic reduction technology. Usually, an aqueous urea solution with a concentration of 32.5% is sprayed into the exhaust pipe. The urea decomposes at high temperatures to produce ammonia, and the ammonia generated reduces NOx in the exhaust gas to nitrogen and water, thereby reducing NOx emissions.

[0086] (5) DPF (Diesel Particulate Filter, particulate trap): used to trap particulate matter in the exhaust gas. When the mass of the trapped particulate matter reaches a certain level, passive regeneration or active regeneration is required to restore the particulate trapping ability of the DPF.

[0087] (6) ccDOC (Close Coupled Diesel Oxide Catalyst): The ccDOC is used to convert NO in the exhaust gas to NO2 to assist the normal operation of the ccSCR.

[0088] (7) DOC (Diesel Oxide Catalyst): The diesel oxide catalyst can be installed in front of the DPF to convert NO in the exhaust gas to NO2, and at the same time increase the exhaust gas temperature to assist the normal operation of the DPF and SCR.

[0089] (8) ASC (Ammonia Slip Catalyst): The ASC is a type of diesel vehicle exhaust after-treatment device installed at the rear end of the SCR to reduce the ammonia leaked in the exhaust gas at the rear end of the SCR through catalytic oxidation.

[0090] In order to improve the SCR conversion efficiency during low-temperature cold start, an engine after-treatment temperature control method, device, electronic device and medium are provided in the embodiments of the present application. To better understand the technical solutions provided in the embodiments of the present application, a brief description of the basic principle of this solution is given here.

[0091] It should be noted that the terms "first", "second", etc. in the specification, claims and above-mentioned drawings of the present application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0092] The technical solutions provided in the embodiments of the present application are introduced below with reference to the drawings.

[0093] For an engine using an SCR aftertreatment system, it is necessary to inject urea into the SCR to react with NOx in the exhaust gas, while generating non-toxic and pollution-free N2 and H2O. 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. Therefore, improving the SCR conversion efficiency during cold start at low temperature is crucial for meeting current emission requirements.

[0094] Currently, in related technologies, the aftertreatment of the engine during the cold start process usually cannot be effectively intervened, resulting in a relatively low SCR conversion efficiency during cold start at low temperature in the existing technologies.

[0095] In view of this, the embodiments of the present application provide an engine aftertreatment temperature control method, device, electronic device and medium. The engine aftertreatment temperature control method is applied to an exhaust aftertreatment system, and the exhaust aftertreatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR aftertreatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet; by responding to an engine start instruction, 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 increase the intake air temperature of the ccDOC system; if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature, intake air temperature and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection amount for in-cylinder post-injection is obtained; taking the measured outlet temperature of the ccDOC system as the feedback value, based on the outlet target temperature, intake air temperature and feedforward control fuel injection amount of the ccDOC system, the closed-loop control fuel injection amount for in-cylinder post-injection is obtained; based on the fuel injection calculation value and a preset fuel injection range threshold, the target fuel injection amount for in-cylinder post-injection is obtained; the fuel injection calculation value is the sum of the feedforward control fuel injection amount and the closed-loop control fuel injection amount; based on the target fuel injection amount for in-cylinder post-injection, the in-cylinder post-injection operation is performed to adjust the outlet temperature of the ccDOC system to the outlet target temperature. This method adds a ccDOC system and a ccSCR system after the exhaust port of the engine, and performs thermal management on the aftertreatment exhaust during cold start of the engine, thereby increasing the aftertreatment temperature, reducing NOx emissions during cold start of the engine, and improving the SCR conversion efficiency during cold start at low temperature.

[0096] The preferred embodiments of the present application will be described below with reference to the accompanying drawings of the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. And without conflict, the embodiments in the embodiments of the present application and the features in the embodiments can be combined with each other.

[0097] Figure 1 An exhaust aftertreatment system provided by an embodiment of the present application is shown. As Figure 1As shown, the exhaust aftertreatment system 100 includes a ccDOC system, a ccSCR system, and an SCR aftertreatment system that are sequentially connected through an exhaust pipe at the engine exhaust outlet.

[0098] 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.

[0099] In some alternative embodiments, the SCR aftertreatment system includes a DOC system, a DPF system, an SCR system, and an ASC system that are sequentially connected through an exhaust pipe.

[0100] In some other embodiments, the exhaust aftertreatment system 100 further includes:

[0101] A third temperature sensor and a fourth temperature sensor, the third temperature sensor is disposed at the outlet of the DOC system, and the fourth temperature sensor is disposed at the outlet of the ASC system.

[0102] The engine aftertreatment temperature control method provided by the embodiments of the present application and applicable to the exhaust aftertreatment system 100 will be further explained below. As Figure 2 shown, it includes the following steps:

[0103] S201, in response to an engine start command, determine that the engine water temperature is lower than a preset first temperature threshold, and perform a first thermal management operation.

[0104] Wherein, the first thermal management operation is used to increase the intake air temperature of the ccDOC system.

[0105] Specifically, the vehicle's ECU can respond to the engine start command, determine that the engine water temperature is lower than the preset first temperature threshold, and perform the first thermal management operation, wherein the first thermal management operation is used to increase the intake air temperature of the ccDOC system.

[0106] Exemplarily, assume that the first temperature threshold is Tem_St1, the vehicle's ECU responds to the engine start command, determines that the engine water temperature Tem_Wa is lower than the preset first temperature threshold Tem_St1, and performs the first thermal management operation, wherein the first thermal management operation is used to increase the intake air temperature T_cD_In of the ccDOC system.

[0107] In the embodiments of the present application, the value of the first temperature threshold Tem_St1 can be in the range of 38 - 42 °C. For example, the first temperature threshold Tem_St1 can be set to 40 °C.

[0108] S202, if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity for post-injection in the cylinder is obtained; using the measured outlet temperature of the ccDOC system as the feedback value, based on the outlet target temperature, intake air temperature, and feedforward control fuel injection quantity of the ccDOC system, the closed-loop control fuel injection quantity for post-injection in the cylinder is obtained.

[0109] During specific implementation, when the vehicle ECU monitors that the intake air temperature of the ccDOC system rises to the preset second temperature threshold, based on the outlet target temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity for post-injection in the cylinder is obtained, and using the measured outlet temperature of the ccDOC system as the feedback value, based on the outlet target temperature, intake air temperature, and feedforward control fuel injection quantity of the ccDOC system, the closed-loop control fuel injection quantity for post-injection in the cylinder is obtained.

[0110] The second temperature threshold of the present application can be set based on the fuel ignition temperature. In some embodiments, the second temperature threshold can take the value of the fuel ignition temperature. For example, the second temperature threshold can be set to 280 °C.

[0111] Exemplarily, if it is monitored that the intake air temperature T_cD_In of the ccDOC system rises to the preset second temperature threshold Tem_St2, based on the outlet target temperature TTar_cD_Ou, intake air temperature T_cD_In, and exhaust gas mass flow rate Mixt_m of the ccDOC system, the feedforward control fuel injection quantity Fuel_Ad for post-injection in the cylinder is obtained; using the measured outlet temperature Treal_cD_Ou of the ccDOC system as the feedback value, based on the outlet target temperature TTar_cD_Ou, intake air temperature T_cD_In, and feedforward control fuel injection quantity Fuel_Ad, the closed-loop control fuel injection quantity Fuel_cl for post-injection in the cylinder is obtained.

[0112] In a possible implementation manner, in step S202, based on the outlet target temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity for post-injection in the cylinder is obtained, as Figure 3 shown, and it can be achieved through the following steps:

[0113] S301, obtain the outlet target temperature of the ccDOC system and the HC conversion efficiency.

[0114] During specific implementation, the vehicle ECU obtains the outlet target temperature TTar_cD_Ou of the ccDOC system and the HC conversion efficiency HC_Perc.

[0115] In a possible implementation, the process of obtaining the hydrocarbon (HC) conversion efficiency of the ccDOC system is specifically as follows: Based on the intake air temperature and the exhaust gas mass flow rate, query the preset conversion rate MAP graph to obtain the HC conversion efficiency of the ccDOC system of the engine; wherein, the conversion rate MAP graph is the mapping relationship between the intake air temperature of the ccDOC system, the engine exhaust gas mass flow rate, and the fuel conversion efficiency of the ccDOC system.

[0116] In the embodiments of the present application, the conversion rate MAP graph can be calibrated through engine bench tests.

[0117] S302, obtain the exhaust gas mass flow rate, intake air temperature, fuel calorific value, and exhaust heat capacity of the engine.

[0118] Exemplarily, the vehicle ECU obtains the exhaust gas mass flow rate Mixt_m, intake air temperature T_cD_In, fuel calorific value Fuel_q, and exhaust heat capacity Mixt_c of the engine.

[0119] S303, take the difference between the outlet target temperature and the intake air temperature to obtain a temperature difference value.

[0120] Exemplarily, the vehicle ECU takes the difference between the outlet target temperature TTar_cD_Ou and the intake air temperature T_cD_In to obtain a temperature difference value T_cD_Gap.

[0121] S304, multiply the exhaust gas mass flow rate by the exhaust heat capacity and the temperature difference value to obtain the heat release demand.

[0122] Exemplarily, the vehicle ECU multiplies the exhaust gas mass flow rate Mixt_m by the exhaust heat capacity Mixt_c and the temperature difference value T_cD_Gap to obtain the heat release demand Q_re.

[0123] S305, divide the heat release demand by the fuel calorific value and the HC conversion efficiency to obtain the feedforward control injection quantity for in-cylinder post-injection.

[0124] Exemplarily, divide the heat release demand Q_re by the fuel calorific value Mixt_c and the HC conversion efficiency HC_Perc to obtain the feedforward control injection quantity Fuel_Ad for in-cylinder post-injection. That is, the feedforward control injection quantity Fuel_Ad can be determined by the following formula:

[0125] Fuel_Ad = Q_re / (Mixt_c · HC_Perc),

[0126] wherein, Fuel_Ad represents the feedforward control injection quantity for in-cylinder post-injection,

[0127] Q_re represents the heat release demand,

[0128] Mixt_c represents the calorific value of the fuel.

[0129] HC_Perc represents the HC conversion efficiency.

[0130] In a possible implementation, in step S202, taking the measured outlet temperature of the ccDOC system as the feedback value, based on the target outlet temperature, inlet temperature of the ccDOC system, and the feedforward control fuel injection quantity, the process of obtaining the closed-loop control fuel injection quantity for in-cylinder post-injection is as Figure 4 shown, and may include the following steps:

[0131] S401, obtain the measured outlet temperature of the ccDOC system.

[0132] Exemplarily, the vehicle ECU obtains the measured outlet temperature Treal_cD_Ou of the ccDOC system.

[0133] S402, compare the measured outlet temperature with the target outlet temperature.

[0134] In some embodiments of the present application, the target outlet temperature can be set to 350 °C. Setting the target outlet temperature to this temperature can reduce NOx emissions during cold engine start-up and improve the SCR conversion efficiency during low-temperature cold start.

[0135] In some other embodiments of the present application, the target outlet temperature can also be obtained by querying the pre-calibrated target temperature MAP based on the inlet temperature and exhaust gas volume flow rate of the ccDOC system. Among them, the target temperature MAP is the mapping relationship between the inlet temperature of the engine ccDOC system, the exhaust gas volume flow rate of the engine, and the target temperature at the outlet of the ccDOC system. Among them, the exhaust gas volume flow rate can be converted by the vehicle ECU based on the exhaust gas mass flow rate.

[0136] The target temperature MAP is a specific data with the inlet temperature of the engine ccDOC system on the X-axis, the exhaust gas volume flow rate of the engine on the Y-axis, and the target temperature at the outlet of the ccDOC system on the Z-axis. Therefore, as long as there are data on the inlet temperature and exhaust gas volume flow rate of the ccDOC system, the target temperature MAP can be queried to obtain the current target temperature at the outlet of the ccDOC system.

[0137] Exemplarily, the vehicle ECU compares the measured outlet temperature Treal_cD_Ou with the target outlet temperature TTar_cD_Ou, and can obtain the outlet temperature comparison result T_cD_Ou_Gap.

[0138] S403, according to the comparison result of the measured outlet temperature and the target outlet temperature, determine the adjustment amount for adjusting the feedforward control fuel injection quantity for in-cylinder post-injection as the closed-loop control fuel injection quantity for in-cylinder post-injection.

[0139] Exemplarily, the ECU of the vehicle determines the adjustment amount for adjusting the feedforward control fuel injection quantity of the post-injection in the cylinder according to the comparison result T_cD_Ou_Gap between the measured outlet temperature and the target outlet temperature, and uses it as the closed-loop control fuel injection quantity Fuel_cl of the post-injection in the cylinder.

[0140] S203. Based on the fuel injection calculation value and the preset fuel injection range threshold, obtain the target fuel injection quantity of the post-injection in the cylinder; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity.

[0141] In specific implementation, the fuel injection range threshold can be preset in the vehicle ECU. The vehicle ECU 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.

[0142] Exemplarily, the vehicle ECU obtains the target fuel injection quantity Fuel_Tar of the 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 fuel injection calculation value Fuel_Ad_math is the sum of the feedforward control fuel injection quantity Fuel_Ad and the closed-loop control fuel injection quantity Fuel_cl.

[0143] In some embodiments of the present application, the smaller value between the fuel injection calculation value of the post-injection in the cylinder calculated by adding the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity and the fuel injection boundary is taken as the final target fuel injection quantity of the post-injection in the cylinder. Among them, the fuel injection boundary can be the fuel injection upper limit value.

[0144] In a possible implementation manner, 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, obtain the target fuel injection quantity of the post-injection in the cylinder, as Figure 5 shown, including the following steps:

[0145] S501. Obtain the fuel injection upper limit value of the engine.

[0146] In a possible implementation manner, obtaining the fuel injection upper limit value of the engine includes the following steps:

[0147] Step A01. Obtain the real-time speed and real-time torque of the engine.

[0148] Step A02. Query the preset fuel injection boundary MAP diagram based on the real-time speed and real-time torque to obtain the fuel injection upper limit value; the fuel injection boundary MAP diagram is the mapping relationship between the engine speed, engine torque and the fuel injection boundary value.

[0149] S502. If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, then use the fuel injection calculation value as the target fuel injection quantity of the post-injection in the cylinder.

[0150] S503. If the fuel injection calculation value is greater than the fuel injection upper limit value, then use the fuel injection upper limit value as the in-cylinder post-injection target fuel injection quantity.

[0151] S204. Perform in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity to adjust the outlet gas temperature of the ccDOC system to the outlet target temperature.

[0152] Exemplarily, the vehicle ECU performs in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity Fuel_Tar to adjust the outlet gas temperature of the ccDOC system to the outlet target temperature TTar_cD_Ou.

[0153] For the engine after-treatment temperature control method of some embodiments of the present application, after step S204, it may also stop the above-mentioned first thermal management operation and the above-mentioned in-cylinder post-injection operation when it is monitored that the engine water temperature is higher than the first temperature threshold.

[0154] In a possible implementation manner, it further includes: if it is monitored that the engine water temperature is higher than the first temperature threshold, then stop the first thermal management operation and the in-cylinder post-injection operation.

[0155] 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 measured outlet gas temperature is obtained from the second temperature sensor between the ccDOC system and the ccSCR system.

[0156] The engine after-treatment temperature control method of the above embodiment is applied to an exhaust after-treatment system. The exhaust after-treatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR after-treatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet. By responding to an 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 executed; the first thermal management operation is used to increase the intake air temperature of the ccDOC system; if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system, the feedforward control fuel injection quantity for in-cylinder post-injection is obtained; using the measured outlet temperature of the ccDOC system as a feedback value, based on the outlet target temperature, intake air temperature, and feedforward control fuel injection quantity of the ccDOC system, the closed-loop control fuel injection quantity for in-cylinder post-injection is obtained; based on the fuel injection calculation value and a preset fuel injection range threshold, the target fuel injection quantity for in-cylinder post-injection 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 target fuel injection quantity for in-cylinder post-injection to adjust the outlet temperature of the ccDOC system to the outlet target temperature. This method adds a ccDOC system and a ccSCR system after the engine exhaust port and performs thermal management on the post-treatment exhaust during cold engine start, thereby increasing the post-treatment temperature, reducing NOx emissions during cold engine start of the engine, and improving the SCR conversion efficiency during low-temperature cold start.

[0157] Based on the same inventive concept, an embodiment of the present application further provides an engine after-treatment temperature control device, which is applied to an exhaust after-treatment system. The exhaust after-treatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR after-treatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet. As Figure 6 shown, the device includes:

[0158] A first thermal management module 601, configured to respond to an 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 increase the intake air temperature of the ccDOC system;

[0159] A first fuel injection quantity control module 602, configured to, if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, obtain the feedforward control fuel injection quantity for in-cylinder post-injection based on the outlet target temperature, intake air temperature, and exhaust gas mass flow rate of the ccDOC system; using the measured outlet temperature of the ccDOC system as a feedback value, obtain the closed-loop control fuel injection quantity for in-cylinder post-injection based on the outlet target temperature, intake air temperature, and feedforward control fuel injection quantity of the ccDOC system;

[0160] The second fuel injection quantity control module 603 is used to obtain the in-cylinder post-injection target fuel injection quantity based on the fuel injection calculation value and a preset fuel injection range threshold value; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity.

[0161] The post-injection execution control module 604 is used to perform in-cylinder post-injection operation based on the in-cylinder post-injection target fuel injection quantity, so as to adjust the outlet gas temperature of the ccDOC system to the outlet target temperature.

[0162] In a possible implementation manner, the fuel injection range threshold value includes a fuel injection upper limit value; the second fuel injection quantity control module 603 is specifically used for:

[0163] Obtain the fuel injection upper limit value of the engine;

[0164] If the fuel injection calculation value is less than or equal to the fuel injection upper limit value, then use the fuel injection calculation value as the in-cylinder post-injection target fuel injection quantity;

[0165] If the fuel injection calculation value is greater than the fuel injection upper limit value, then use the fuel injection upper limit value as the in-cylinder post-injection target fuel injection quantity.

[0166] In a possible implementation manner, the second fuel injection quantity control module 603 is specifically used for:

[0167] Obtain the real-time engine speed and real-time torque;

[0168] Query a preset fuel injection boundary MAP diagram based on the real-time speed and real-time torque to obtain the fuel injection upper limit value; the fuel injection boundary MAP diagram is the mapping relationship between the engine speed, engine torque and the fuel injection boundary value.

[0169] In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

[0170] Obtain the outlet target temperature of the ccDOC system and the hydrocarbon HC conversion efficiency;

[0171] Obtain the exhaust gas mass flow rate, intake air temperature, fuel calorific value and exhaust heat capacity of the engine;

[0172] Take the difference between the outlet target temperature and the intake air temperature to obtain a temperature difference value;

[0173] Multiply the exhaust gas mass flow rate by the exhaust heat capacity and the temperature difference value to obtain a heat release demand;

[0174] Divide the heat release demand by the fuel calorific value and the HC conversion efficiency to obtain the feedforward control fuel injection quantity for in-cylinder post-injection.

[0175] In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

[0176] Based on the intake air temperature and the exhaust gas mass flow rate, query the preset conversion rate MAP graph to obtain the hydrocarbon (HC) conversion efficiency of the ccDOC system of the engine;

[0177] Among them, the conversion rate MAP graph is the mapping relationship between the intake air temperature of the ccDOC system, the exhaust gas mass flow rate of the engine, and the fuel conversion efficiency of the ccDOC system.

[0178] In a possible implementation manner, as Figure 7 shown, the device further includes a cold start control exit module 701, and the cold start control exit module 701 is used for:

[0179] If it is monitored that the engine water temperature is higher than the first temperature threshold, stop the first thermal management operation and the in-cylinder post-injection operation.

[0180] 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 measured outlet temperature is obtained from the second temperature sensor between the ccDOC system and the ccSCR system.

[0181] In a possible implementation manner, the first fuel injection quantity control module 602 is specifically used for:

[0182] Obtain the measured outlet temperature of the ccDOC system;

[0183] Compare the measured outlet temperature with the target outlet temperature;

[0184] According to the comparison result between the measured outlet temperature and the target outlet temperature, determine the adjustment amount for adjusting the feedforward control fuel injection quantity of the in-cylinder post-injection, and use it as the closed-loop control fuel injection quantity of the in-cylinder post-injection.

[0185] Based on the same inventive concept, an embodiment of the present application further provides an electronic device. Referring to Figure 8 shown, this electronic device is used to implement the methods described in the above-mentioned various method embodiments. For example, to implement the method as Figure 2 shown, the electronic device may include a memory 801, a processor 802, an input unit 803, and a display panel 804.

[0186] A memory 801 for storing a computer program executed by a processor 802. The memory 801 may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system, application programs required for 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 (CPU) or a digital processing unit, etc. An input unit 803 may be used to obtain user instructions input by a user. A display panel 804 is used to display information input by the user or information provided to the user. In the embodiments of the present application, the display panel 804 is mainly used to display the display interfaces of various application programs in the terminal device and the control entities displayed in the display interfaces. Optionally, the display panel 804 may be configured in the form of a liquid crystal display (LCD) or an OLED (organic light-emitting diode), etc.

[0187] In the embodiments of the present application, the specific connection medium between the above-mentioned memory 801, processor 802, input unit 803 and display panel 804 is not limited. In the embodiments of the present application Figure 8 it is shown that the memory 801, processor 802, input unit 803, and display panel 804 are connected through a bus 805. The bus 805 is shown as a thick line Figure 8 herein. The connection methods between other components are only for illustrative purposes and are not to be construed as limiting. The bus 805 may be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 8 only a thick line is shown herein, but it does not mean that there is only one bus or one type of bus.

[0188] The memory 801 may be a volatile memory, such as a random-access memory (RAM); the memory 801 may also be a non-volatile memory, such as a read-only memory, a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), or the memory 801 is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 801 may be a combination of the above-mentioned memories.

[0189] A processor 802, configured to call a computer program stored in a memory 801 to execute the embodiments as described above, for example, to execute Figure 2 the steps of the method as shown.

[0190] An embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions required to be executed by the above-mentioned processor, which includes a program required to be executed by the above-mentioned processor.

[0191] In some possible implementation manners, various aspects of an engine aftertreatment temperature control method provided by the present application can also be implemented in the form of a program product, which includes program code. When the program product runs on a terminal device, the program code is used to cause the terminal device to execute the steps in an engine aftertreatment temperature control method according to various exemplary embodiments of the present application described above in this specification. For example, an electronic device can execute the embodiments as shown in Figure 2 the embodiments.

[0192] The program product can adopt any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0193] The engine aftertreatment temperature control program product according to the embodiment of the present application can adopt a portable compact disk read-only memory (CD-ROM) and include program code, and can run on a computing device. However, the program product of the present application is not limited thereto. In this document, the readable storage medium can be any tangible medium that contains or stores a program that can be used by or in combination with an instruction execution system, apparatus, or device.

[0194] The readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, in which the readable program code is carried. Such a propagated data signal can take various forms, including - but not limited to - an electromagnetic signal, an optical signal, or any suitable combination of the above. The readable signal medium can also be any readable medium other than the readable storage medium, which can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device.

[0195] The program code contained on a readable medium can be transmitted using any appropriate medium, including - but not limited to - wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0196] The program code for performing the operations of this application can be written in any combination of one or more programming languages. The programming languages include object-oriented programming languages such as Java, C++, etc., and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can execute entirely on the user's computing device, partially on the user's device, execute as a stand-alone software package, execute partially on the user's computing device and partially on a remote computing device, or execute entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., by using an Internet service provider to connect through the Internet).

[0197] It should be noted that although several units or subunits of the device are mentioned in the foregoing detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more of the units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0198] Moreover, although the operations of the method of this application are described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all of the operations shown must be performed to achieve the desired result. 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.

[0199] Those skilled in the art should understand that the embodiments of this application can be provided as a method, a system, or a computer program product. Therefore, this application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0200] This application is described with reference to the 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 flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, as well as the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable file processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable file processing devices generate means for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0201] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable file processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0202] These computer program instructions can also be loaded onto a computer or other programmable file processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0203] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0204] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, 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 changes and modifications.

Claims

1. An engine after-treatment temperature control method, characterized in that, Applied to an exhaust aftertreatment system, the exhaust aftertreatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR aftertreatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet; the method includes: In response to an engine start command, determine that the engine water temperature is lower than a preset first temperature threshold, and perform a first thermal management operation; the first thermal management operation is used to increase the intake air temperature of the ccDOC system. If it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, then based on the outlet target temperature of the ccDOC system, the intake air temperature, and the exhaust gas mass flow rate, obtain the feedforward control fuel injection quantity for in-cylinder post-injection; using the measured outlet temperature of the ccDOC system as the feedback value, based on the outlet target temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection quantity, obtain the closed-loop control fuel injection quantity for in-cylinder post-injection. Based on the fuel injection calculation value and a preset fuel injection range threshold, obtain the target fuel injection quantity for in-cylinder post-injection; the fuel injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity. Perform in-cylinder post-injection operation based on the target fuel injection quantity for in-cylinder post-injection to adjust the outlet temperature of the ccDOC system to the outlet target temperature.

2. The method according to claim 1, wherein The fuel injection range threshold includes a fuel injection upper limit value; the obtaining of the target fuel injection quantity for in-cylinder post-injection based on the fuel injection calculation value and a preset fuel injection range threshold 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, then use the fuel injection calculation value as the target fuel injection quantity for in-cylinder post-injection. If the fuel injection calculation value is greater than the fuel injection upper limit value, then use the fuel injection upper limit value as the target fuel injection quantity for in-cylinder post-injection.

3. The method according to claim 2, characterized in that, The obtaining of the fuel injection upper limit value of the engine includes: Obtain the real-time engine speed and real-time torque. Based on the real-time engine speed and the real-time torque, query a preset fuel injection boundary MAP chart to obtain the fuel injection upper limit value; the fuel injection boundary MAP chart is the mapping relationship between the engine speed, engine torque, and fuel injection boundary value.

4. The method according to claim 1, wherein The obtaining of the feedforward control fuel injection quantity for in-cylinder post-injection based on the outlet target temperature of the ccDOC system, the intake air temperature, and the exhaust gas mass flow rate includes: Obtain the outlet target temperature of the ccDOC system and the hydrocarbon HC conversion efficiency. Obtain the exhaust gas mass flow rate, the intake air temperature, the fuel calorific value, and the exhaust heat capacity value of the engine. Take the difference between the outlet target temperature and the intake air temperature to obtain a temperature difference value. Multiply the exhaust gas mass flow rate by the exhaust heat capacity value and the temperature difference value to obtain the heat release demand. Divide the heat release demand by the fuel calorific value and the HC conversion efficiency to obtain the feedforward control fuel injection quantity for in-cylinder post-injection.

5. The method according to claim 4, wherein The obtaining of the hydrocarbon 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 chart to obtain the hydrocarbon (HC) conversion efficiency of the ccDOC system of the engine; Wherein, the conversion rate MAP chart is a mapping relationship between the intake air temperature of the ccDOC system, the engine exhaust gas mass flow rate, and the fuel conversion efficiency of the ccDOC system.

6. The method according to claim 1, wherein The method further includes: If it is monitored that the engine water temperature is higher than the first temperature threshold, stop the first thermal management operation and the in-cylinder post-injection operation.

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

8. The method according to claim 1, wherein Taking the measured outlet temperature of the ccDOC system as a feedback value, based on the target outlet temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection quantity, obtaining the closed-loop control fuel injection quantity for in-cylinder post-injection includes: Obtain the measured outlet temperature of the ccDOC system; Compare the measured outlet temperature with the target outlet temperature; According to the comparison result between the measured outlet temperature and the target outlet temperature, determine the adjustment amount for adjusting the feedforward control fuel injection quantity for in-cylinder post-injection, and use it as the closed-loop control fuel injection quantity for in-cylinder post-injection.

9. An engine after-treatment temperature control device, characterized in that, Applied to an exhaust aftertreatment system, the exhaust aftertreatment system includes a close-coupled oxidation catalytic converter ccDOC system, a close-coupled selective catalytic reduction device ccSCR system, and a selective catalytic reduction device SCR aftertreatment system that are sequentially connected through an exhaust pipe at the engine exhaust gas outlet; the device includes: A first thermal management module, configured to determine that the engine water temperature is lower than a preset first temperature threshold in response to an engine start command, and perform a first thermal management operation; the first thermal management operation is used to increase the intake air temperature of the ccDOC system; A first fuel injection quantity control module, configured to, if it is monitored that the intake air temperature of the ccDOC system rises to a preset second temperature threshold, obtain the feedforward control fuel injection quantity for in-cylinder post-injection based on the target outlet temperature of the ccDOC system, the intake air temperature, and the exhaust gas mass flow rate; taking the measured outlet temperature of the ccDOC system as a feedback value, based on the target outlet temperature of the ccDOC system, the intake air temperature, and the feedforward control fuel injection quantity, obtain the closed-loop control fuel injection quantity for in-cylinder post-injection; A second fuel injection quantity control module, configured to obtain the target fuel injection quantity for in-cylinder post-injection based on an injection calculation value and a preset injection range threshold; the injection calculation value is the sum of the feedforward control fuel injection quantity and the closed-loop control fuel injection quantity; A post-injection execution control module, configured to perform an in-cylinder post-injection operation based on the target fuel injection quantity for in-cylinder post-injection to adjust the outlet temperature of the ccDOC system to the target outlet temperature.

10. An electronic device, characterized in that, It includes a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 8.

11. A computer-readable storage medium storing a computer program therein, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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