Exhaust gas aftertreatment method, device, computer program product and vehicle

Abstract

The application provides a tail gas aftertreatment method, device, computer program product and vehicle. The aftertreatment system comprises an SCR and a heater. The heater is installed on a tail gas pipeline upstream of the SCR. The method comprises: a first acquisition step of acquiring an SCR tail gas temperature in real time. The SCR tail gas temperature is the temperature of tail gas in the SCR. A second acquisition step of acquiring a plurality of oil injection amounts within a predetermined time period under the condition that the SCR tail gas temperature is less than a high-efficiency temperature threshold. The high-efficiency temperature threshold is the minimum temperature of the SCR with a conversion efficiency greater than a predetermined conversion efficiency. A first control step of controlling the heater to be turned on for tail gas heating under the condition that all the oil injection amounts within the predetermined time period are less than an oil injection amount threshold. A second control step of controlling the heater to be turned off under the condition that any one of the oil injection amounts within the predetermined time period is greater than or equal to the oil injection amount threshold. The problem of high power consumption of the tail gas heater in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tail gas treatment, in particular to a tail gas aftertreatment method, device, computer program product and vehicle. BACKGROUND

[0002] With the current emission level being increasingly stringent, cold start emission and low load leading to a decrease in aftertreatment temperature is a key concern, and a decrease in aftertreatment temperature will lead to SCR conversion efficiency, and in turn lead to non-compliance of NOx emission, therefore, there are two solutions in the traditional scheme, one is to use a heater to heat the tail gas under cold start emission and low load conditions to ensure the SCR conversion efficiency, but the heater consumes a large amount of electric energy, making it difficult for the vehicle to load the electric quantity, and the other is to increase the fuel injection amount under cold start emission and low load conditions to increase the tail gas temperature, resulting in high fuel consumption. SUMMARY

[0003] The main purpose of the present application is to provide a tail gas aftertreatment method, device, computer program product and vehicle to at least solve the problem of high power consumption of the tail gas heater in the prior art.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a tail gas aftertreatment method is provided, the aftertreatment system comprising an SCR and a heater, the heater being installed on a tail gas pipeline upstream of the SCR, the method comprising: a first acquisition step of acquiring the SCR tail gas temperature in real time, the SCR tail gas temperature being the temperature of the tail gas in the SCR; a second acquisition step of acquiring a plurality of fuel injection amounts within a predetermined time period under the condition that the SCR tail gas temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being the minimum temperature of the SCR at which the conversion efficiency is greater than a predetermined conversion efficiency; a first control step of controlling the heater to be turned on for tail gas heating under the condition that all of the plurality of fuel injection amounts within the predetermined time period are less than a fuel injection amount threshold; and a second control step of controlling the heater to be turned off under the condition that any one of the fuel injection amounts within the predetermined time period is greater than or equal to the fuel injection amount threshold.

[0005] Optionally, in the case that any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, the control of the heater to be closed includes: in the case that any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, obtaining a first NOx concentration and a second NOx concentration, the first NOx concentration being a NOx concentration of exhaust gas at an inlet of the SCR, and the second NOx concentration being a NOx concentration of exhaust gas at an outlet of the SCR; calculating a conversion efficiency of the SCR according to the first NOx concentration and the second NOx concentration; in the case that the conversion efficiency of the SCR is less than the predetermined conversion efficiency, controlling the heater to be opened to heat the exhaust gas; and in the case that the conversion efficiency of the SCR is greater than or equal to the predetermined conversion efficiency, controlling the heater to be closed.

[0006] Optionally, in the case that the conversion efficiency of the SCR is less than the predetermined conversion efficiency, the control of the heater to be opened to heat the exhaust gas includes: performing a test of a plurality of first heating powers in a first scenario to obtain a plurality of the first heating powers satisfying the NOx emission requirement, the first scenario being a scenario in which the exhaust gas temperature of the SCR is less than the high-efficiency temperature threshold and any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold; determining a minimum value of the plurality of the first heating powers satisfying the NOx emission requirement as a first optimal heating power of the first scenario; and in the case that the conversion efficiency of the SCR is less than the predetermined conversion efficiency, controlling the heater to heat the exhaust gas at the first optimal heating power.

[0007] Optionally, in the case that all of the fuel injection amounts in the predetermined time period are less than the fuel injection amount threshold, the control of the heater to be opened to heat the exhaust gas includes: in the case that all of the fuel injection amounts in the predetermined time period are less than the fuel injection amount threshold, determining that the engine is in a long-time low-load working condition; in the case that there is a NOx emission requirement in the long-time low-load working condition, controlling the heater to be opened to heat the exhaust gas; and in the case that there is no NOx emission requirement in the long-time low-load working condition, controlling the heater to be closed.

[0008] Optionally, in the case that there is a NOx emission requirement in the long-time low-load working condition, the heater is controlled to be turned on for exhaust gas heating, including: performing a plurality of second heating power tests in a second scenario to obtain a plurality of second heating powers that meet the NOx emission requirement, the second scenario being a scenario in which the SCR exhaust gas temperature is less than the high-efficiency temperature threshold and each of the plurality of injection amounts in the predetermined time period is less than the injection amount threshold; determining a minimum value of the plurality of second heating powers that meet the NOx emission requirement as a second optimal heating power of the second scenario; and in the case that there is the NOx emission requirement in the long-time low-load working condition, controlling the heater to perform exhaust gas heating at the second optimal heating power.

[0009] Optionally, the aftertreatment system further comprises a first temperature sensor and a second temperature sensor, the first temperature sensor being installed on an exhaust pipe between the SCR and the heater, and the second temperature sensor being installed on an exhaust pipe downstream of the SCR, the real-time SCR exhaust gas temperature being obtained by: obtaining a SCR pre-exhaust gas temperature and a SCR post-exhaust gas temperature in real time, the SCR pre-exhaust gas temperature being a temperature of exhaust gas detected by the first temperature sensor, and the SCR post-exhaust gas temperature being a temperature of exhaust gas detected by the second temperature sensor; and calculating an average of the SCR pre-exhaust gas temperature and the SCR post-exhaust gas temperature to obtain the SCR exhaust gas temperature.

[0010] Optionally, the method further comprises: in the case that the SCR exhaust gas temperature is greater than or equal to the high-efficiency temperature threshold, sequentially repeating the first obtaining step, the second obtaining step, the first control step and the second control step at least once until the engine stops running.

[0011] According to another aspect of the present application, there is provided an exhaust gas aftertreatment device, the aftertreatment system comprising an SCR and a heater, the heater being installed on an exhaust pipe upstream of the SCR, the device comprising: a first obtaining unit configured to perform a first obtaining step of obtaining a real-time SCR exhaust gas temperature, the SCR exhaust gas temperature being a temperature of exhaust gas in the SCR; a second obtaining unit configured to perform a second obtaining step of obtaining a plurality of injection amounts in a predetermined time period in the case that the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being a minimum temperature of the SCR at which a conversion efficiency is greater than a predetermined conversion efficiency; a first control unit configured to perform a first control step of controlling the heater to be turned on for exhaust gas heating in the case that each of the plurality of injection amounts in the predetermined time period is less than an injection amount threshold; and a second control unit configured to perform a second control step of controlling the heater to be turned off in the case that any one of the plurality of injection amounts in the predetermined time period is greater than or equal to the injection amount threshold.

[0012] According to still another aspect of the present application, there is provided a computer program product comprising a computer program which, when executed by a processor, implements any of the methods described.

[0013] According to yet another aspect of the present application, there is provided a vehicle comprising an engine, an aftertreatment system, one or more processors, a memory, and one or more programs, wherein the aftertreatment system comprises an SCR and a heater mounted on an exhaust pipe upstream of the SCR, the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise instructions for implementing any of the methods described.

[0014] By applying the technical solution of the present application, in the aftertreatment method described above, the SCR exhaust temperature is acquired in real time, and if the SCR exhaust temperature is less than the high-efficiency temperature threshold, it indicates that the exhaust temperature is too low to affect the conversion efficiency of the SCR. Further, a plurality of injection amounts within a predetermined time period are acquired, and each of the plurality of injection amounts within the predetermined time period is less than an injection amount threshold, indicating that the engine is in a long-time low-load working condition. Therefore, the heater needs to be controlled to be turned on to heat the exhaust. Otherwise, the temperature continues to decrease, resulting in non-compliance with the NOx emission requirements. If any of the injection amounts within the predetermined time period is greater than or equal to the injection amount threshold, it indicates that the engine will not be in a long-time low-load working condition, and the exhaust temperature will not continue to decrease. Therefore, the heater does not need to heat the exhaust. Compared with the prior art in which the exhaust is heated when the exhaust temperature is low, the present application greatly saves electric energy and solves the problem of high power consumption of the exhaust heater in the prior art. Moreover, the present application does not increase the injection amount to increase the exhaust temperature, thereby saving fuel consumption. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A hardware structure block diagram of a mobile terminal for performing an exhaust aftertreatment method according to an embodiment of the present application is shown;

[0016] Figure 2 A schematic diagram of an aftertreatment system according to an embodiment of the present application is shown;

[0017] Figure 3 A flowchart of an exhaust aftertreatment method according to an embodiment of the present application is shown;

[0018] Figure 4 A flowchart of an exhaust aftertreatment method for a short-time low-load working condition according to an embodiment of the present application is shown;

[0019] Figure 5 A flowchart of another exhaust aftertreatment method according to an embodiment of the present application is shown;

[0020] Figure 6A structural block diagram of a tail gas aftertreatment device is shown.

[0021] In the above drawings, reference numerals:

[0022] 102, processor; 104, memory; 106, transmission device; 108, input and output device. DETAILED DESCRIPTION

[0023] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] For the convenience of description, the following describes some nouns or terms related to the embodiments of the present application:

[0027] EH: Electrical Heater, electric heater;

[0028] DPF: Diesel Particulate Filter, particulate matter trap;

[0029] DOC: Diesel Oxidation Catalyst, diesel oxidation catalyst;

[0030] SCR: Selective Catalytic Reduction, selective catalytic reduction;

[0031] ASC: Ammonia Slip Catalytic, ammonia oxidation catalyst.

[0032] As introduced in the background technology, the power consumption of the exhaust gas heater in the prior art is high. To solve this technical problem, the embodiments of the present application provide an exhaust gas after-treatment method, device, computer program product and vehicle.

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 FIG. 1 is a hardware structure diagram of a mobile terminal of an exhaust gas post-processing method according to an embodiment of the present invention. Figure 1 As shown, the mobile terminal may include one or more ( Figure 1 Only one is shown) a processor 102 (the processor 102 may include but is not limited to a microprocessor MCU or a programmable logic device FPGA and other processing devices) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0035] The memory 104 can be used to store computer programs, such as software programs of application software and modules, such as a computer program corresponding to the exhaust gas aftertreatment method in the embodiments of the present application. The processor 102 can execute various functional applications and data processing, i.e., implement the above method, by running the computer program stored in the memory 104. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include a memory remotely arranged with respect to the processor 102, which can be connected to the mobile terminal through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The transmission device 106 is used to receive or send data via a network. The specific examples of the above network can include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet in a wireless manner.

[0036] In the embodiments, an exhaust gas aftertreatment method running on a mobile terminal, a computer terminal, or a similar computing device is provided, such as Figure 2 As shown in the figure, the aftertreatment system includes an SCR and a heater (EH), and the heater (EH) is installed on an exhaust pipe upstream of the SCR. It should be noted that the steps shown in the flowchart can be executed in a computer system, such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0037] Figure 3 is a flowchart of the exhaust gas aftertreatment method according to the embodiments of the present application. As shown in the figure, the method includes the following steps: Figure 3

[0038] Step S201, a first acquisition step, acquiring an SCR exhaust gas temperature in real time, the SCR exhaust gas temperature being a temperature of exhaust gas in the SCR;

[0039] Step S202, a second acquisition step, acquiring a plurality of injection amounts within a predetermined time length in a case where the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being a minimum temperature of the SCR at which a conversion efficiency is greater than a predetermined conversion efficiency;

[0040] ​Step S203, a first control step, in the case that the plurality of fuel injection amounts in the predetermined time length are all less than the fuel injection amount threshold, controlling the heater to be turned on to heat the exhaust gas;

[0041] Step S204, a second control step, in the case that any one of the plurality of fuel injection amounts in the predetermined time length is greater than or equal to the fuel injection amount threshold, controlling the heater to be turned off.

[0042] In the exhaust gas aftertreatment method, the SCR exhaust gas temperature is obtained in real time. If the SCR exhaust gas temperature is less than the high-efficiency temperature threshold, it indicates that the exhaust gas temperature is too low to affect the conversion efficiency of the SCR. Further, a plurality of fuel injection amounts in a predetermined time length are obtained. If the plurality of fuel injection amounts in the predetermined time length are all less than the fuel injection amount threshold, it indicates that the engine is in a long-time low-load working condition, and the heater needs to be turned on to heat the exhaust gas. Otherwise, the temperature continues to decrease, which does not meet the NOx emission requirements. If any one of the plurality of fuel injection amounts in the predetermined time length is greater than or equal to the fuel injection amount threshold, it indicates that the engine will not be in a long-time low-load working condition, and the exhaust gas temperature will not continue to decrease, so the heater does not need to heat the exhaust gas. Compared with the prior art, the heater is turned on to heat the exhaust gas when the exhaust gas temperature is low, which greatly saves the electric energy and solves the problem of high power consumption of the exhaust gas heater in the prior art. Moreover, the fuel injection amount is not increased to increase the exhaust gas temperature, and the fuel consumption is saved.

[0043] It should be noted that, as shown in Figure 2 The aftertreatment system further includes a particulate matter trap (DPF), a diesel oxidation catalyst (DOC), an ammonia oxidation catalyst (ASC), and temperature sensors T3, T4, T5, and T6 for detecting the intake temperature of the diesel oxidation catalyst (DOC), the intake temperature of the particulate matter trap (DPF), the intake temperature and the outlet temperature of the selective catalytic reduction (SCR), respectively. The upstream and downstream of the aftertreatment system each have a NOx sensor 1 and a NOx sensor 2, respectively, for detecting the NOx concentration in the exhaust gas before the exhaust gas aftertreatment and the NOx concentration in the exhaust gas after the exhaust gas aftertreatment.

[0044] In order to ensure that the emission requirements are met, in an optional embodiment, as shown in Figure 4 The step S204 includes:

[0045] Step S2041, in the case that any one of the plurality of fuel injection amounts in the predetermined time length is greater than or equal to the fuel injection amount threshold, obtaining a first NOx concentration and a second NOx concentration. The first NOx concentration is the NOx concentration of the exhaust gas at the intake of the SCR, and the second NOx concentration is the NOx concentration of the exhaust gas at the outlet of the SCR.

[0046] Step S2042, calculating the conversion efficiency of the SCR according to the first NOx concentration and the second NOx concentration.

[0047] Step S2043, in the case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency, controlling the heater to be turned on for exhaust gas heating;

[0048] Step S2044, in the case where the conversion efficiency of the SCR is greater than or equal to the predetermined conversion efficiency, controlling the heater to be turned off.

[0049] In the above embodiment, in the case where any one of the injection amounts in the predetermined time period is greater than or equal to the injection amount threshold, it indicates that the engine is not in a long-time low-load working condition, but the temperature is still low to cause low conversion efficiency, thereby causing the NOx emission requirement not to be met. Therefore, in this case, the NOx concentrations in the exhaust gas before and after the SCR are detected by the NOx sensor 1 and the NOx sensor 2 to obtain the first NOx concentration and the second NOx concentration, the conversion efficiency of the SCR is calculated by the formula: conversion efficiency = (first NOx concentration - second NOx concentration) / first NOx concentration, and in the case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency, the heater needs to be turned on for exhaust gas heating, and the EH is turned on at the rated power PI for rapid heating to improve the conversion efficiency of the SCR, otherwise, it is not needed. The predetermined conversion efficiency can be selected according to actual needs, for example, 95%.

[0050] In order to further save electric energy, in an optional embodiment, the step S2043 comprises:

[0051] Step S20431, performing a plurality of first heating power tests in a first scenario to obtain a plurality of first heating powers that meet the NOx emission requirement, the first scenario being a scenario where the exhaust gas temperature of the SCR is less than the high-efficiency temperature threshold and any one of the injection amounts in the predetermined time period is greater than or equal to the injection amount threshold;

[0052] Step S20432, determining the minimum value of the plurality of first heating powers that meet the NOx emission requirement as the first optimal heating power of the first scenario;

[0053] Step S20433, in the case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency, controlling the heater to perform exhaust gas heating at the first optimal heating power.

[0054] In the above embodiment, the working condition that the SCR tail gas temperature is less than the high-efficiency temperature threshold and any one of the fuel injection amounts in the predetermined time length is greater than or equal to the fuel injection amount threshold is set as a first scene, and the minimum first heating power that meets the NOx emission requirement is found by performing multiple calibrations in the first scene, that is, a first optimal heating power is obtained. In the subsequent first scene, the first optimal heating power is used for tail gas heating when heating is needed, so as to ensure that the NOx emission requirement is met, reduce power consumption, save electric energy, and relieve the electric quantity load pressure of the vehicle.

[0055] In order to further save electric energy, in an optional embodiment, the step S203 includes:

[0056] In step S2031, in the case that all the fuel injection amounts in the predetermined time length are less than the fuel injection amount threshold, it is determined that the engine is in a long-time low-load working condition.

[0057] In step S2032, in the case that there is an NOx emission requirement in the long-time low-load working condition, the heater is controlled to be turned on to perform tail gas heating.

[0058] In step S2033, in the case that there is no NOx emission requirement in the long-time low-load working condition, the heater is controlled to be turned off.

[0059] In the above embodiment, if the SCR tail gas temperature Tscr is less than TH, it is considered that the SCR enters a low-temperature and low-efficiency stage, and then the vehicle is judged whether it is in a long-time low-load working condition in combination with the fuel injection amount threshold q0 and the predetermined time length t1. If the fuel injection amount q is lower than the calibrated fuel injection amount threshold q0 within the predetermined time length t1, it is considered that the engine is in a long-time low-load working condition. In order to meet the NOx emission requirement, the heater (EH) is turned on at the calibrated power P2 to compensate for the situation that the aftertreatment temperature is reduced due to the reduction of the load. P2 is calibrated according to the low-load emission requirement to maintain the aftertreatment at a suitable temperature. When the low-load emission is not considered, P3=0, so as to avoid the waste of electric energy caused by long-time heating.

[0060] In order to further save electric energy, in an optional embodiment, the step S2032 includes:

[0061] In step S20321, multiple second heating powers are tested in a second scene to obtain multiple second heating powers that meet the NOx emission requirement. The second scene is a scene that the SCR tail gas temperature is less than the high-efficiency temperature threshold and all the fuel injection amounts in the predetermined time length are less than the fuel injection amount threshold.

[0062] In step S20322, the minimum value of the multiple second heating powers that meet the NOx emission requirement is determined as a second optimal heating power of the second scene.

[0063] Step S20323, in the case where the long-time low-load working condition has the above-mentioned NOx emission requirement, the above-mentioned heater is controlled to perform exhaust gas heating at the above-mentioned second optimal heating power.

[0064] In the above-mentioned embodiment, the working condition where the above-mentioned SCR exhaust gas temperature is less than the above-mentioned high-efficiency temperature threshold and the above-mentioned multiple fuel injection amounts within the above-mentioned predetermined time length are all less than the above-mentioned fuel injection amount threshold is set as a second scenario, and multiple calibrations are performed in the second scenario to find a minimum second heating power that meets the NOx emission requirement, i.e., to obtain a second optimal heating power. The second optimal heating power is used to perform exhaust gas heating in the subsequent second scenario, so as to ensure that the NOx emission requirement is met while reducing power consumption, saving electric energy, and relieving the electric quantity load pressure of the vehicle.

[0065] In order to obtain the SCR exhaust gas temperature, in an optional embodiment, the above-mentioned exhaust aftertreatment system further comprises a first temperature sensor and a second temperature sensor, the above-mentioned first temperature sensor is installed on the exhaust pipe between the above-mentioned SCR and the above-mentioned heater, and the above-mentioned second temperature sensor is installed on the exhaust pipe downstream of the above-mentioned SCR. The above-mentioned step S201 comprises:

[0066] Step S2011, real-time acquisition of the SCR front exhaust gas temperature and the SCR rear exhaust gas temperature, the SCR front exhaust gas temperature being the temperature of the exhaust gas detected by the above-mentioned first temperature sensor, and the SCR rear exhaust gas temperature being the temperature of the exhaust gas detected by the above-mentioned second temperature sensor;

[0067] Step S2012, calculation of the average value of the above-mentioned SCR front exhaust gas temperature and the above-mentioned SCR rear exhaust gas temperature to obtain the above-mentioned SCR exhaust gas temperature.

[0068] In the above-mentioned embodiment, the temperature sensors T5 and T6 are used to selectively select the inlet temperature and the outlet temperature of the selective catalytic reduction (SCR) to calculate the SCR exhaust gas temperature T scr = (T5+T6) / 2, so as to determine whether the SCR exhaust gas temperature Tscr is greater than the high-efficiency temperature threshold TH H of the high-efficiency stage of the SCR. If the SCR exhaust gas temperature Tscr is less than TH, it is considered that the SCR enters the low-temperature and low-efficiency stage. Test proves that the conversion efficiency of the SCR is above 95% when the average temperature is above 200℃, i.e., the high-efficiency temperature threshold TH H of the SCR can be 200℃. Of course, the high-efficiency temperature threshold TH H of different types of SCR is different.

[0069] In order to ensure that the NOx emission requirement is met during the entire engine operation period, in an optional embodiment, the above-mentioned method further comprises:

[0070] Step S301, in the case that the SCR exhaust gas temperature is greater than or equal to the high-efficiency temperature threshold, the first obtaining step, the second obtaining step, the first control step and the second control step are repeated at least once in sequence until the engine stops running.

[0071] In the above embodiment, the SCR exhaust gas temperature greater than or equal to the high-efficiency temperature threshold indicates that the SCR is in a high-efficiency stage, and the first obtaining step, the second obtaining step, the first control step and the second control step are repeated at least once in sequence to ensure that the NOx emission requirements are met while saving electric energy, and the engine stops running.

[0072] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the exhaust gas aftertreatment method of the present application will be described in detail below in conjunction with specific embodiments.

[0073] The present embodiment relates to a specific exhaust gas aftertreatment method, as shown in Figure 5 The method comprises the following steps:

[0074] The engine is started, and the aftertreatment temperature, engine speed, torque, and fuel injection amount in the ECU are read to determine the operating condition of the engine by detecting the amount:

[0075] (a) According to the fuel injection amount and the temperature, it is determined that the engine is in a low-load state:

[0076] It is determined whether the average SCR temperature Tscr is greater than the minimum temperature TH at which the SCR enters the high-efficiency stage (experimental results show that the conversion efficiency is above 95% when the average SCR temperature reaches above 200°C); if so, it is considered that the SCR efficiency meets the emission requirements, and the EH does not need to be turned on;

[0077] (b) If the average SCR temperature T scr is less than TH, it is considered that the SCR enters the low-temperature and low-efficiency stage, and the fuel injection amount q0 and the time t1 are combined to determine whether the vehicle is in a long-time low-load operating condition; if the fuel injection amount q is lower than the low-load fuel injection amount boundary q0 within the specified time t1, it is considered that the engine is in a long-time low-load operating condition, and the EH is turned on according to the specified power P2 to compensate for the decrease in aftertreatment temperature due to the decrease in load, and P2 is specified according to the low-load emission requirements to maintain the aftertreatment at an appropriate temperature. Or when the low-load emission is not considered, P3=0, to avoid waste of electric energy caused by long-time heating;

[0078] (c) otherwise, it is considered that the engine is not in the low load condition for a long time, but is still in the low temperature and low efficiency stage, at this time, the SCR conversion efficiency e is calculated by the two-way NOx emission values collected by the NOx sensor, if the calculated efficiency e is greater than e0, e0 is the minimum SCR conversion efficiency calibrated to meet the emission requirements in the low temperature and low efficiency stage. Then EH does not need to be started, otherwise it is considered that the current SCR conversion efficiency does not meet the emission requirements, and EH is started according to the rated power P1 to quickly warm up and improve the SCR efficiency.

[0079] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0080] The embodiment of the present application also provides a tail gas aftertreatment device. It should be noted that the tail gas aftertreatment device of the embodiment of the present application can be used to execute the tail gas aftertreatment method provided by the embodiment of the present application. The device is used to realize the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiments is preferably realized in software, hardware, or a combination of software and hardware is also possible and is contemplated.

[0081] The tail gas aftertreatment device provided by the embodiment of the present application is introduced below.

[0082] Figure 6 is a structural block diagram of the tail gas aftertreatment device according to the embodiment of the present application. As shown in Figure 6 , the device includes:

[0083] The first acquisition unit 10 is used to execute the first acquisition step, and acquires the SCR tail gas temperature in real time, wherein the SCR tail gas temperature is the temperature of the tail gas in the SCR;

[0084] The second acquisition unit 20 is used to execute the second acquisition step, and acquires a plurality of fuel injection amounts within a predetermined time period under the condition that the SCR tail gas temperature is less than a high efficiency temperature threshold, wherein the high efficiency temperature threshold is the minimum temperature of the SCR at which the conversion efficiency is greater than a predetermined conversion efficiency;

[0085] The first control unit 30 is used to execute the first control step, and controls the heater to be turned on for tail gas heating under the condition that all of the plurality of fuel injection amounts within the predetermined time period are less than a fuel injection amount threshold;

[0086] The second control unit 40 is configured to perform a second control step, in which, in a case where any one of the plurality of fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, the heater is controlled to be turned off.

[0087] In the exhaust gas aftertreatment device, the SCR exhaust gas temperature is obtained in real time. If the SCR exhaust gas temperature is less than the high-efficiency temperature threshold, it indicates that the exhaust gas temperature is too low to affect the conversion efficiency of the SCR. Further, a plurality of fuel injection amounts in a predetermined time period are obtained. If all the fuel injection amounts in the predetermined time period are less than the fuel injection amount threshold, it indicates that the engine is in a long-time low-load working condition, and the heater needs to be turned on to heat the exhaust gas. Otherwise, the temperature continues to decrease, which does not meet the NOx emission requirements. If any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, it indicates that the engine is not in a long-time low-load working condition, and the exhaust gas temperature will not continue to decrease. Therefore, the heater does not need to heat the exhaust gas. Compared with the prior art in which the exhaust gas is heated when the exhaust gas temperature is low, the electric energy is greatly saved, the problem of high power consumption of the exhaust gas heater in the prior art is solved, and the fuel consumption is saved without increasing the fuel injection amount to increase the exhaust gas temperature.

[0088] It should be noted that, as shown in Figure 2 The aftertreatment system further includes a particulate matter trap (DPF), a diesel oxidation catalyst (DOC), an ammonia oxidation catalyst (ASC), and temperature sensors T3, T4, T5, and T6 for detecting the intake temperature of the diesel oxidation catalyst (DOC), the intake temperature of the particulate matter trap (DPF), the intake temperature and the outlet temperature of the selective catalytic reduction device (SCR), respectively. The upstream and downstream of the aftertreatment system each have a NOx sensor 1 and a NOx sensor 2, respectively, for detecting the NOx concentration in the exhaust gas before the exhaust gas aftertreatment and the NOx concentration in the exhaust gas after the exhaust gas aftertreatment.

[0089] In order to ensure that the emission requirements are met, in an optional embodiment, as shown in Figure 4 The second control unit includes:

[0090] The first obtaining module is configured to, in a case where any one of the plurality of fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, obtain a first NOx concentration and a second NOx concentration. The first NOx concentration is the NOx concentration of the exhaust gas at the inlet of the SCR, and the second NOx concentration is the NOx concentration of the exhaust gas at the outlet of the SCR.

[0091] The first calculation module is configured to calculate the conversion efficiency of the SCR according to the first NOx concentration and the second NOx concentration.

[0092] The first control module is configured to, in a case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency, control the heater to be turned on to heat the exhaust gas.

[0093] a second control module configured to control the heater to be turned off when the conversion efficiency of the SCR is greater than or equal to the predetermined conversion efficiency.

[0094] In the above embodiment, when any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold, it indicates that the engine is not in a long-time low-load working condition, but the temperature is still low to cause low conversion efficiency, thereby failing to meet the NOx emission requirement. Therefore, in this case, the first NOx concentration and the second NOx concentration are obtained by detecting the NOx concentrations in the exhaust gas before and after the SCR through the NOx sensor 1 and the NOx sensor 2, the conversion efficiency of the SCR is calculated through the formula of conversion efficiency = (first NOx concentration-second NOx concentration) / first NOx concentration, and the heater needs to be turned on for exhaust gas heating when the conversion efficiency of the SCR is less than the predetermined conversion efficiency. The EH is turned on at the rated power PI to rapidly increase the temperature and improve the conversion efficiency of the SCR, otherwise, the heater does not need to be turned on. The predetermined conversion efficiency can be selected according to actual needs, for example, 95%.

[0095] In order to further save electric energy, in an optional embodiment, the first control module comprises:

[0096] a first test submodule configured to test a plurality of first heating powers in a first scenario to obtain a plurality of first heating powers meeting the NOx emission requirement, the first scenario being a scenario in which the exhaust gas temperature of the SCR is less than the high-efficiency temperature threshold and any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold;

[0097] a first determination submodule configured to determine the minimum value of the plurality of first heating powers meeting the NOx emission requirement as a first optimal heating power of the first scenario;

[0098] a first control submodule configured to control the heater to heat the exhaust gas at the first optimal heating power when the conversion efficiency of the SCR is less than the predetermined conversion efficiency.

[0099] In the above embodiment, the working condition in which the exhaust gas temperature of the SCR is less than the high-efficiency temperature threshold and any one of the fuel injection amounts in the predetermined time period is greater than or equal to the fuel injection amount threshold is set as the first scenario, and a plurality of calibrations are performed in the first scenario to find the minimum first heating power meeting the NOx emission requirement, i.e., to obtain the first optimal heating power. The first optimal heating power is used for exhaust gas heating in the subsequent first scenario to ensure that the NOx emission requirement is met while reducing power consumption, saving electric energy, and relieving the electric power load pressure of the vehicle.

[0100] To further save electric energy, in an optional embodiment, the first control unit comprises:

[0101] A determination module is configured to determine that the engine is in a long-time low-load working condition if all the injection amounts in the predetermined time period are less than the injection amount threshold value.

[0102] A third control module is configured to control the heater to be turned on to heat exhaust gas if there is a NOx emission requirement in the long-time low-load working condition.

[0103] A fourth control module is configured to control the heater to be turned off if there is no NOx emission requirement in the long-time low-load working condition.

[0104] In the above embodiment, if the SCR exhaust gas temperature Tscr is less than TH, it is considered that the SCR enters a low-temperature and low-efficiency stage, and then the injection amount threshold value q0 and the predetermined time period t1 are used to determine whether the vehicle is in a long-time low-load working condition. If the injection amount q is less than the calibrated injection amount threshold value q0 in the predetermined time period t1, it is considered that the engine is in a long-time low-load working condition. In order to meet the NOx emission requirement, the heater (EH) is turned on at a calibrated power P2 to compensate for the decrease in the exhaust gas temperature caused by the decrease in the load. P2 is calibrated according to the low-load emission requirement to maintain the aftertreatment at a suitable temperature. When the low-load emission is not considered, P3=0 to avoid waste of electric energy caused by long-time heating.

[0105] To further save electric energy, in an optional embodiment, the third control module comprises:

[0106] A second test submodule is configured to test a plurality of second heating powers in a second scenario to obtain a plurality of second heating powers that meet the NOx emission requirement. The second scenario is a scenario in which the SCR exhaust gas temperature is less than the high-efficiency temperature threshold value and all the injection amounts in the predetermined time period are less than the injection amount threshold value.

[0107] A second determination submodule is configured to determine the minimum value of the plurality of second heating powers that meet the NOx emission requirement as a second optimal heating power of the second scenario.

[0108] A second control submodule is configured to control the heater to heat exhaust gas at the second optimal heating power if there is the NOx emission requirement in the long-time low-load working condition.

[0109] In the above embodiment, the working condition in which the SCR exhaust gas temperature is less than the high-efficiency temperature threshold and the plurality of fuel injection amounts in the predetermined time length are all less than the fuel injection amount threshold is set as a second scenario, and the second optimal heating power is found by performing multiple calibrations in the second scenario to meet the NOx emission requirement, i.e., the second optimal heating power is obtained. In the subsequent second scenario, the second optimal heating power is used for exhaust gas heating when heating is required, so as to ensure that the NOx emission requirement is met while reducing power consumption, saving electric energy, and relieving the electric quantity load pressure of the vehicle.

[0110] In order to obtain the SCR exhaust gas temperature, in an optional embodiment, the aftertreatment system further comprises a first temperature sensor and a second temperature sensor, the first temperature sensor is installed on the exhaust pipe between the SCR and the heater, and the second temperature sensor is installed on the exhaust pipe downstream of the SCR, and the first obtaining unit comprises:

[0111] The second obtaining module is configured to obtain the SCR pre-exhaust gas temperature and the SCR post-exhaust gas temperature in real time, the SCR pre-exhaust gas temperature is the temperature of the exhaust gas detected by the first temperature sensor, and the SCR post-exhaust gas temperature is the temperature of the exhaust gas detected by the second temperature sensor.

[0112] The second calculation module is configured to calculate the average value of the SCR pre-exhaust gas temperature and the SCR post-exhaust gas temperature to obtain the SCR exhaust gas temperature.

[0113] In the above embodiment, the temperature sensors T5 and T6 are used to selectively obtain the inlet temperature and outlet temperature of the selective catalytic reduction (SCR) device, and the SCR exhaust gas temperature T scr = (T5+T6) / 2 is calculated to determine whether the SCR exhaust gas temperature Tscr is greater than the high-efficiency temperature threshold T H If the SCR exhaust gas temperature Tscr is less than TH, it is considered that the SCR enters a low-temperature and low-efficiency stage, and experiments show that the conversion efficiency of the SCR is above 95% when the average temperature is above 200℃, i.e., the high-efficiency temperature threshold T H may be 200℃. Of course, the high-efficiency temperature threshold T H of different types of SCR devices is different.

[0114] In order to ensure that the engine meets the NOx emission requirement during the entire operation period, in an optional embodiment, the device further comprises:

[0115] The repeating unit is configured to repeatedly perform the first obtaining step, the second obtaining step, the first control step, and the second control step at least once in sequence when the SCR exhaust gas temperature is greater than or equal to the high-efficiency temperature threshold, until the engine stops operating.

[0116] In the above embodiment, when the SCR exhaust gas temperature is greater than or equal to the high-efficiency temperature threshold, it indicates that the SCR is in a high-efficiency stage, and the entering of the cold start emission and the low load (low-temperature low-efficiency stage) is continuously monitored, and the first acquisition step, the second acquisition step, the first control step and the second control step are repeatedly performed at least once, so as to ensure that the NOx emission requirement is met while saving electric energy, until the engine stops running.

[0117] The exhaust gas aftertreatment device includes a processor and a memory, and the first acquisition unit, the second acquisition unit, the first control unit and the second control unit are stored in the memory as program units, and the corresponding functions are realized by the processor executing the program units stored in the memory. The modules are located in the same processor; or, the modules are located in different processors in any combination.

[0118] The processor includes a core, and the core retrieves the corresponding program unit from the memory. The core can be one or more, and the problem of high power consumption of the exhaust gas heater in the prior art can be solved by adjusting the core parameters.

[0119] The memory can include a non-persistent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory includes at least one memory chip.

[0120] The embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium includes a stored program, wherein the program controls the device where the computer readable storage medium is located to perform the exhaust gas aftertreatment method when the program is running.

[0121] Specifically, the exhaust gas aftertreatment method includes:

[0122] Step S201, a first acquisition step, real-time acquisition of an SCR exhaust gas temperature, the SCR exhaust gas temperature being the temperature of the exhaust gas in the SCR;

[0123] Step S202, a second acquisition step, acquisition of a plurality of fuel injection amounts within a predetermined time period when the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being the minimum temperature of the SCR at which the conversion efficiency is greater than a predetermined conversion efficiency;

[0124] Step S203, a first control step, control of the heater to be turned on for exhaust gas heating when all the fuel injection amounts within the predetermined time period are less than a fuel injection amount threshold;

[0125] Step S204, a second control step, in a case where any one of the injection amounts in the predetermined time length is greater than or equal to the injection amount threshold, controlling the heater to be turned off.

[0126] An embodiment of the present application provides a processor, which is used for running a program, wherein the processor implements the exhaust gas aftertreatment method when running the program.

[0127] Specifically, the exhaust gas aftertreatment method comprises:

[0128] Step S201, a first acquisition step, acquiring an SCR exhaust gas temperature in real time, the SCR exhaust gas temperature being a temperature of exhaust gas in the SCR;

[0129] Step S202, a second acquisition step, in a case where the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, acquiring a plurality of injection amounts in a predetermined time length, the high-efficiency temperature threshold being a minimum temperature of the SCR at which a conversion efficiency is greater than a predetermined conversion efficiency;

[0130] Step S203, a first control step, in a case where all of the injection amounts in the predetermined time length are less than an injection amount threshold, controlling the heater to be turned on to heat the exhaust gas;

[0131] Step S204, a second control step, in a case where any one of the injection amounts in the predetermined time length is greater than or equal to the injection amount threshold, controlling the heater to be turned off.

[0132] An embodiment of the present application provides a vehicle, which comprises an engine, an aftertreatment system, a processor, a memory, and a program stored in the memory and capable of running on the processor, the aftertreatment system comprising an SCR and a heater, the heater being installed on an exhaust pipe upstream of the SCR, and the processor implementing at least the following steps when running the program:

[0133] Step S201, a first acquisition step, acquiring an SCR exhaust gas temperature in real time, the SCR exhaust gas temperature being a temperature of exhaust gas in the SCR;

[0134] Step S202, a second acquisition step, in a case where the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, acquiring a plurality of injection amounts in a predetermined time length, the high-efficiency temperature threshold being a minimum temperature of the SCR at which a conversion efficiency is greater than a predetermined conversion efficiency;

[0135] Step S203, a first control step, in a case where all of the injection amounts in the predetermined time length are less than an injection amount threshold, controlling the heater to be turned on to heat the exhaust gas;

[0136] Step S204, a second control step, controls the heater to be turned off when any of the fuel injection amounts within the predetermined time period is greater than or equal to the fuel injection amount threshold.

[0137] The present application also provides a computer program product, which, when executed on a data processing device, is adapted to execute a program for initializing at least the following method steps:

[0138] Step S201, a first acquisition step, real-time acquisition of the SCR exhaust gas temperature, where the SCR exhaust gas temperature is the temperature of the exhaust gas in the SCR;

[0139] Step S202, a second acquisition step, in which a plurality of fuel injection amounts within a predetermined time period are acquired when the SCR exhaust temperature is less than a high-efficiency temperature threshold, wherein the high-efficiency temperature threshold is the lowest temperature of the SCR at which the conversion efficiency is greater than a predetermined conversion efficiency;

[0140] Step S203, a first control step, controlling the heater to turn on to heat the exhaust gas when the plurality of fuel injection amounts within the predetermined time period are all less than the fuel injection amount threshold;

[0141] Step S204, a second control step, controls the heater to be turned off when any of the fuel injection amounts within the predetermined time period is greater than or equal to the fuel injection amount threshold.

[0142] Obviously, those skilled in the art will appreciate that the various modules or steps of the present invention described above can be implemented using a general-purpose computing device, can be centralized on a single computing device, or can be distributed across a network of multiple computing devices. They can be implemented using program code executable by the computing device, and thus, can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described herein can be performed in a different order than that shown, or can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0143] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0144] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0145] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0146] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0147] In one typical configuration, the computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0148] The memory can include non-persistent memory and / or persistent memory, such as flash memory, read-only memory (ROM), and / or volatile or non-volatile random access memory (RAM), among others. The memory is an example of computer readable media.

[0149] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology for information storage. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0150] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0151] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0152] 1) In the tail gas aftertreatment method of the present application, the SCR tail gas temperature is obtained in real time. If the SCR tail gas temperature is less than the high-efficiency temperature threshold, it indicates that the tail gas temperature is too low to affect the conversion efficiency of the SCR. Further, a plurality of fuel injection amounts within a predetermined time period are obtained. If all the fuel injection amounts within the predetermined time period are less than the fuel injection amount threshold, it indicates that the engine is in a long-time low-load working condition. Therefore, the heater needs to be controlled to be turned on for tail gas heating. Otherwise, the temperature will continue to decrease, resulting in non-compliance with the NOx emission requirements. If any of the above fuel injection amounts within the predetermined time period is greater than or equal to the fuel injection amount threshold, it indicates that the engine will not be in a long-time low-load working condition, and the tail gas temperature will not continue to decrease. Therefore, the heater is not needed to heat the tail gas. Compared with the prior art, the tail gas is heated when the tail gas temperature is low, which greatly saves electric energy, solves the problem of high power consumption of the tail gas heater in the prior art, and does not increase the fuel injection amount to increase the tail gas temperature, thereby saving fuel consumption.

[0153] 2) In the exhaust after-treatment device of the present application, the SCR exhaust temperature is obtained in real time. If the SCR exhaust temperature is less than the high-efficiency temperature threshold, it indicates that the exhaust temperature is too low, affecting the conversion efficiency of the SCR. Further, multiple fuel injection amounts within a predetermined time period are obtained. If the multiple fuel injection amounts within the predetermined time period are all less than the fuel injection amount threshold, it indicates that the engine is in a long-term low-load condition. In this case, it is necessary to control the heater to turn on for exhaust heating, otherwise the temperature continues to drop, resulting in failure to meet the NOx emission requirements. Any of the above-mentioned fuel injection amounts within the predetermined time period is greater than or equal to the above-mentioned fuel injection amount threshold, indicating that the engine will not be in a long-term low-load condition, the exhaust temperature will not continue to drop, and there is no need for a heater to heat the exhaust. Compared with the prior art in which the exhaust temperature is low and heating is performed, electric energy is greatly saved, the problem of high power consumption of the exhaust heater in the prior art is solved, and the fuel injection amount is not increased to increase the exhaust temperature, thus saving fuel consumption.

[0154] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method of exhaust gas aftertreatment, characterized in that, The post-processing system comprises an SCR and a heater installed on an exhaust pipe upstream of the SCR, and the method comprises: a first acquisition step of acquiring an SCR exhaust temperature in real time, the SCR exhaust temperature being a temperature of exhaust gas in the SCR; a second acquisition step of acquiring a plurality of injection amounts within a predetermined time period, in a case where the SCR exhaust temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being a minimum temperature of the SCR at which conversion efficiency is greater than a predetermined conversion efficiency; a first control step of controlling the heater to be turned on for exhaust heating, in a case where all of the plurality of injection amounts within the predetermined time period are less than an injection amount threshold; a second control step of controlling the heater to be turned off, in a case where any one of the plurality of injection amounts within the predetermined time period is greater than or equal to the injection amount threshold.

2. The method of claim 1, wherein, controlling the heater to be turned off in a case where any one of the plurality of injection amounts within the predetermined time period is greater than or equal to the injection amount threshold, comprises: acquiring a first NOx concentration and a second NOx concentration in a case where any one of the plurality of injection amounts within the predetermined time period is greater than or equal to the injection amount threshold, the first NOx concentration being a NOx concentration of exhaust gas at an inlet of the SCR, and the second NOx concentration being a NOx concentration of exhaust gas at an outlet of the SCR; calculating the conversion efficiency of the SCR according to the first NOx concentration and the second NOx concentration; controlling the heater to be turned on for exhaust heating in a case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency; controlling the heater to be turned off in a case where the conversion efficiency of the SCR is greater than or equal to the predetermined conversion efficiency.

3. The method of claim 2, wherein, controlling the heater to be turned on for exhaust heating in a case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency, comprises: performing a plurality of first heating power tests in a first scenario to obtain a plurality of first heating powers that satisfy a NOx emission requirement, the first scenario being a scenario in which the SCR exhaust temperature is less than the high-efficiency temperature threshold and any one of the plurality of injection amounts within the predetermined time period is greater than or equal to the injection amount threshold; determining a minimum value of the plurality of first heating powers that satisfy the NOx emission requirement as a first optimal heating power for the first scenario; and controlling the heater to perform exhaust heating at the first optimal heating power in a case where the conversion efficiency of the SCR is less than the predetermined conversion efficiency.

4. The method of claim 1, wherein, controlling the heater to be turned on for exhaust heating in a case where all of the plurality of injection amounts within the predetermined time period are less than an injection amount threshold, comprises: determining that the engine is in a long-time low-load working condition in a case where all of the plurality of injection amounts within the predetermined time period are less than the injection amount threshold; controlling the heater to be turned on for exhaust heating in a case where there is a NOx emission requirement in the long-time low-load working condition; controlling the heater to be turned off in a case where there is no NOx emission requirement in the long-time low-load working condition.

5. The method of claim 4, wherein, controlling the heater to be turned on for exhaust heating in a case where there is a NOx emission requirement in the long-time low-load working condition, comprises: In a second scenario, a plurality of second heating powers are tested to obtain a plurality of the second heating powers satisfying the NOx emission requirement, the second scenario being a scenario in which the SCR exhaust gas temperature is less than the high-efficiency temperature threshold and each of the plurality of the injection amounts in the predetermined time length is less than the injection amount threshold; a minimum value of the plurality of the second heating powers satisfying the NOx emission requirement is determined as a second optimal heating power of the second scenario; in a case where the NOx emission requirement exists in a long-time low-load working condition, the heater is controlled to perform exhaust gas heating at the second optimal heating power.

6. The method according to any one of claims 1 to 5, characterized in that, The aftertreatment system further comprises a first temperature sensor and a second temperature sensor, the first temperature sensor being installed on an exhaust pipe between the SCR and the heater, and the second temperature sensor being installed on an exhaust pipe downstream of the SCR, to obtain a real-time SCR exhaust gas temperature, including: obtaining a real-time SCR pre-exhaust gas temperature and a real-time SCR post-exhaust gas temperature, the SCR pre-exhaust gas temperature being a temperature of exhaust gas detected by the first temperature sensor, and the SCR post-exhaust gas temperature being a temperature of exhaust gas detected by the second temperature sensor; calculating an average value of the SCR pre-exhaust gas temperature and the SCR post-exhaust gas temperature to obtain the SCR exhaust gas temperature.

7. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: in a case where the SCR exhaust gas temperature is greater than or equal to the high-efficiency temperature threshold, sequentially repeating the first obtaining step, the second obtaining step, the first control step and the second control step at least once until the engine stops running.

8. An exhaust gas aftertreatment device, characterized by The aftertreatment system comprises an SCR and a heater, the heater being installed on an exhaust pipe upstream of the SCR, and the device comprises: a first obtaining unit configured to perform a first obtaining step to obtain a real-time SCR exhaust gas temperature, the SCR exhaust gas temperature being a temperature of exhaust gas in the SCR; a second obtaining unit configured to perform a second obtaining step to obtain a plurality of injection amounts in a predetermined time length in a case where the SCR exhaust gas temperature is less than a high-efficiency temperature threshold, the high-efficiency temperature threshold being a minimum temperature of the SCR at which a conversion efficiency is greater than a predetermined conversion efficiency; a first control unit configured to perform a first control step to control the heater to be turned on to perform exhaust gas heating in a case where each of the plurality of the injection amounts in the predetermined time length is less than an injection amount threshold; a second control unit configured to perform a second control step to control the heater to be turned off in a case where any one of the injection amounts in the predetermined time length is greater than or equal to the injection amount threshold.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the method of any one of claims 1 to 7.

10. A vehicle characterized by comprising: including: An engine, an aftertreatment system, one or more processors, a memory, and one or more programs, wherein the aftertreatment system includes an SCR and a heater mounted on an exhaust pipe upstream of the SCR, the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs include instructions for performing the method of any one of claims 1-7.

Images