Method and device for testing conversion efficiency of scr, electronic equipment and storage medium

Abstract

The present application provides a kind of SCR conversion efficiency test method, device, electronic equipment and storage medium, test method includes steps: control engine closes urea injection and in preset operating condition, run preset time, receive the first detection information of gas discharged by SCR system;Control engine opens urea injection and in preset operating condition, run preset time, receive the second detection information of gas discharged by SCR system;According to the first detection information and the second detection information, calculate SCR conversion efficiency.The test method is by controlling engine in injection urea and not injection urea two kinds of mode under fixed mode operation, and respectively above-mentioned two mode under the detection information of SCR exhaust gas, according to the detection information corresponding to ideal situation and the detection information corresponding to actual situation, the conversion efficiency of SCR system can be calculated.Exclude the influence of inaccurate theoretical model, closed loop control logic, high precision.Secondly, this method can be automatically realized by program, simple and easy to operate.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method, apparatus, electronic device, and storage medium for testing SCR conversion efficiency. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Currently, we are in the transition from Stage III to Stage IV non-road emission standards, a phase of upgraded emission regulations. For engines using SCR technology that meet Stage IV emission requirements, the means to investigate the cause of excessive nitrogen oxide emissions are insufficient. There is a lack of accurate methods to identify whether the excessive nitrogen oxide emissions are due to low SCR conversion efficiency. Although there are methods to test SCR conversion efficiency, the theoretical models for nitrogen oxide concentration are affected by temperature and humidity, and the existence of a closed-loop nitrogen oxide emission strategy makes it impossible to accurately control the urea injection volume. Therefore, existing monitoring methods cannot obtain a true and accurate SCR conversion efficiency. Summary of the Invention

[0004] The purpose of this invention is to at least solve the problem of inaccurate calculation of SCR conversion efficiency using existing SCR monitoring methods. This purpose is achieved through the following technical solution:

[0005] The first aspect of this invention provides a method for testing SCR conversion efficiency, comprising the following steps:

[0006] Control the engine to shut off urea injection and run it under preset conditions for a preset time, and receive the first detection information of the gas discharged from the SCR system;

[0007] Control the engine to start urea injection and run it under the preset operating conditions for the preset time, and receive the second detection information of the gas discharged by the SCR system;

[0008] The SCR conversion efficiency is calculated based on the first detection information and the second detection information.

[0009] The SCR conversion efficiency testing method proposed in this invention controls the engine to operate under preset conditions for preset time in both urea injection and non-urea injection modes, and records the emission information of the engine's SCR system in both modes. The first detection information when the engine is running without urea injection can be used to calculate the theoretical ideal conversion rate of the SCR system operating under preset conditions for the preset time. The second detection information when the engine is running with urea injection can be used to calculate the actual conversion rate of the SCR system operating under preset conditions for the preset time. The conversion efficiency of the SCR system can then be calculated based on the theoretical ideal conversion rate and the actual conversion rate. This SCR conversion efficiency testing method can be programmed into a computer program stored in the storage medium of a repair tool. During vehicle after-sales service, the repair tool is connected to the engine ECU, allowing the computer program configured with this SCR conversion efficiency testing method to control the engine via the ECU, receive signals, and calculate the SCR system's conversion efficiency. This SCR conversion efficiency testing method can eliminate the influence of inaccurate theoretical models and closed-loop control logic, resulting in high accuracy. Furthermore, this method can be automatically implemented by a program, making it simple and easy to operate.

[0010] In addition, the SCR conversion efficiency testing method according to the present invention may also have the following additional technical features:

[0011] In some embodiments of the present invention, the first detection information includes a first nitrogen oxide concentration value downstream of the SCR system, and the second detection information includes a second nitrogen oxide concentration value downstream of the SCR system.

[0012] In some embodiments of the present invention, the step of controlling the engine to start urea injection and operate under the preset conditions for the preset time, and receiving second detection information of the gas discharged from the SCR system includes:

[0013] Calculate the urea consumption of the engine during the preset operating condition for the preset time;

[0014] The engine is controlled to run under the preset operating conditions for the preset time, urea injection is activated and the urea injection amount is controlled to be the urea consumption amount, and the second nitrogen oxide concentration value is received.

[0015] In some embodiments of the present invention, the step of calculating the SCR conversion efficiency based on the first detection information and the second detection information includes:

[0016] The SCR conversion efficiency is calculated according to the formula C = (AB) / A, where A is the concentration of the first nitrogen oxide, B is the concentration of the second nitrogen oxide, and C is the SCR conversion efficiency.

[0017] In some embodiments of the present invention, the first nitrogen oxide concentration value and the second nitrogen oxide concentration value are obtained by monitoring a nitrogen oxide concentration sensor located downstream of the SCR system, and both the first nitrogen oxide concentration value and the second nitrogen oxide concentration value are the average nitrogen oxide concentration values ​​monitored by the nitrogen oxide concentration sensor within the preset time period.

[0018] In some embodiments of the present invention, in the steps of controlling the engine to run under the preset operating conditions for the preset time, starting urea injection and controlling the urea injection amount to be the urea consumption amount, and receiving the second nitrogen oxide concentration value, the urea injection device is controlled to uniformly inject the urea consumption amount within the preset time.

[0019] In some embodiments of the present invention, the engine is maintained at a fixed speed under the preset operating conditions.

[0020] A second aspect of the present invention provides an SCR conversion efficiency testing device, the SCR conversion efficiency testing device comprising:

[0021] The control module is used to control the engine to operate in the states of urea injection off and urea injection on, respectively;

[0022] The acquisition module is used to acquire detection information of the gas discharged from the SCR system of the engine;

[0023] The calculation module is used to calculate the true conversion efficiency of SCR based on the detection information.

[0024] The SCR conversion efficiency testing device proposed in the second aspect of the present invention has the same beneficial effects as the SCR conversion efficiency testing method proposed in the first aspect of the present invention, and will not be described again here.

[0025] A third aspect of the present invention provides an electronic device comprising: a processor, a memory, and a computer program; wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program including instructions for performing the SCR conversion efficiency testing method proposed in the first aspect of the present invention.

[0026] A fourth aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the SCR conversion efficiency testing method proposed in the first aspect of the present invention. Attached Figure Description

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0028] In the attached diagram:

[0029] Figure 1 A schematic flowchart of an SCR conversion efficiency testing method according to an embodiment of the present invention is shown. Detailed Implementation

[0030] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0031] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0032] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0033] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0034] like Figure 1 As shown, the first aspect of the present invention proposes a method for testing SCR conversion efficiency, comprising the following steps:

[0035] Control the engine to shut off urea injection and run it under preset conditions for a preset time, and receive the first detection information of the gas discharged from the SCR system;

[0036] Control the engine to start urea injection and run it under preset conditions for a preset time, and receive the second detection information of the gas discharged from the SCR system;

[0037] The SCR conversion efficiency is calculated based on the first and second detection information.

[0038] The function of the SCR system is to remove nitrogen oxides from engine exhaust. The SCR system uses urea as a reducing agent; under the reduction action of a selective catalytic converter, nitrogen oxides are reduced to nitrogen and water. The SCR system mainly includes a urea solution tank, a urea injection device, a metering device, a catalytic converter, and temperature and exhaust gas sensors. The urea solution tank stores the urea solution. The metering device includes a metering pump and a controller. The metering pump delivers the urea solution at a specific pressure. The controller communicates with the ECU via a CAN bus, receives control signals from the ECU, calculates the urea injection quantity, and controls the metering pump to deliver the urea solution. The urea injection device includes urea nozzles, which inject urea solution according to the controller's instructions.

[0039] Urea undergoes the following hydrolysis reaction when dissolved in water:

[0040] CO(NH2)2 + H2O → 2NH3 + CO2

[0041] When urea solution comes into contact with exhaust gases from an engine, the following chemical reaction occurs:

[0042] 4NH3 + 2H2O + O2 → 3N2 + 6H2O;

[0043] 4NH3 + 4NO + O2 → 4N2 + 6H2O;

[0044] 2NH3 + NO + NO2 → 2N2 + 3H2O;

[0045] The working process of the SCR system

[0046] The SCR conversion efficiency testing method proposed in this invention controls the engine to operate under preset conditions for preset time in both urea injection and non-urea injection modes, and records the emission information of the engine's SCR system in both modes. The first detection information when the engine is running without urea injection can be used to calculate the theoretical ideal conversion rate of the SCR system operating under preset conditions for the preset time. The second detection information when the engine is running with urea injection can be used to calculate the actual conversion rate of the SCR system operating under preset conditions for the preset time. The conversion efficiency of the SCR system can then be calculated based on the theoretical ideal conversion rate and the actual conversion rate. This SCR conversion efficiency testing method can be programmed into a computer program stored in the storage medium of a repair tool. During vehicle after-sales service, the repair tool is connected to the engine ECU, allowing the computer program configured with this SCR conversion efficiency testing method to control the engine via the ECU, receive signals, and calculate the SCR system's conversion efficiency. This SCR conversion efficiency testing method can eliminate the influence of inaccurate theoretical models and closed-loop control logic, resulting in high accuracy. Furthermore, this method can be automatically implemented by a program, making it simple and easy to operate.

[0047] In some embodiments of the present invention, the first detection information includes a first nitrogen oxide concentration value downstream of the SCR system, and the second detection information includes a second nitrogen oxide concentration value downstream of the SCR system.

[0048] The nitrogen oxide concentration value is obtained from a nitrogen oxide concentration sensor located downstream of the SCR system. The nitrogen oxide concentration sensor can be located at the exhaust port of the SCR system and is connected to the ECU to transmit the monitored nitrogen oxide concentration to the ECU.

[0049] In some embodiments of the present invention, the step of controlling the engine to start urea injection and operate under preset conditions for a preset time, and receiving second detection information of the gas discharged from the SCR system includes:

[0050] The urea consumption of the engine under preset operating conditions for a preset time is calculated based on the reaction equation of ammonia and nitrogen oxides.

[0051] Control the engine to run under preset operating conditions for a preset time, activate urea injection and control the urea injection amount to the urea consumption amount, and receive the second nitrogen oxide concentration value.

[0052] The preset operating condition refers to the engine's normal stable operating condition. The preset time can be selected to be approximately thirty minutes. In this embodiment, the engine is controlled to run under normal stable operating conditions for approximately thirty minutes, while the urea injection device of the SCR system is controlled to inject urea. The urea injection amount is calculated based on the reaction equation of ammonia and nitrogen oxides. In the reaction equation of ammonia and nitrogen oxides, the amount of nitrogen oxides is obtained from the first nitrogen oxide concentration value monitored by the nitrogen oxide concentration sensor when the engine runs under the same preset operating conditions for thirty minutes without urea injection. Substituting the first nitrogen oxide concentration value monitored by the nitrogen oxide concentration sensor into the formula yields the amount of urea. The urea injection amount is equal to the calculated amount of urea. Based on this, the exhaust nitrogen oxide concentration of the engine is determined for a fixed time under fixed operating conditions. The urea consumption under the condition that all nitrogen oxides are converted by the SCR system is deduced from the exhaust nitrogen oxide concentration, which is the urea consumption under the most ideal condition. Urea is then injected based on the urea consumption under the most ideal condition. Finally, the SCR conversion efficiency is calculated based on the first nitrogen oxide concentration value and the second nitrogen oxide concentration value.

[0053] In some embodiments of the present invention, the step of calculating the SCR conversion efficiency based on the first detection information and the second detection information includes:

[0054] The SCR conversion efficiency is calculated using the formula C = (AB) / A, where A is the concentration of the first nitrogen oxide, B is the concentration of the second nitrogen oxide, and C is the SCR conversion efficiency.

[0055] The first nitrogen oxide concentration value is the nitrogen oxide concentration in the exhaust gas of the SCR system obtained by running the engine under preset operating conditions for a preset time without urea injection. The second nitrogen oxide concentration value is the nitrogen oxide concentration in the exhaust gas of the SCR system obtained by running the engine under preset operating conditions for a preset time with urea injected at a calculated injection rate. The calculated injection rate is the urea consumption assuming all nitrogen oxides generated by the engine running under preset operating conditions for a preset time are converted by the SCR system. The above formula calculates the true conversion efficiency of the SCR system based on the first nitrogen oxide concentration value corresponding to the maximum conversion efficiency of the SCR system and the second nitrogen oxide concentration value corresponding to the actual conversion efficiency of the SCR system, using a weighted approach. This eliminates the influence of inaccurate theoretical models and closed-loop control logic, resulting in high accuracy. Furthermore, this method can be implemented automatically by a computer program that controls the engine and automatically acquires monitoring values ​​and performs calculations, making it simple and easy to operate.

[0056] In some embodiments of the present invention, the first nitrogen oxide concentration value and the second nitrogen oxide concentration value are obtained by monitoring a nitrogen oxide concentration sensor located downstream of the SCR system. Both the first nitrogen oxide concentration value and the second nitrogen oxide concentration value are the average nitrogen oxide concentration values ​​monitored by the nitrogen oxide concentration sensor within a preset time period.

[0057] The working principle of the nitrogen and oxygen concentration sensor is to electrically heat the zirconium dioxide chamber of the sensor to 600°C. Due to the difference in oxygen concentration on both sides, the zirconium dioxide undergoes a chemical reaction, resulting in the movement of charges on both sides of the electrodes. The moving charges generate an electric current. The magnitude of the generated current reflects the difference in oxygen concentration, and the oxygen concentration is fed back to the controller to calculate the current nitrogen and oxygen concentration, which is then transmitted to the ECU via the CAN bus.

[0058] In this embodiment, multiple nitrogen oxide concentration values ​​can be obtained by monitoring multiple times within a preset time period, and then the average nitrogen oxide concentration value is obtained by averaging. This avoids the influence of engine operating condition fluctuations on the nitrogen oxide concentration in the exhaust gas, and thus avoids the need for SCR conversion efficiency calculation.

[0059] In some embodiments of the present invention, in the steps of controlling the engine to operate under preset conditions for a preset time, activating urea injection and controlling the urea injection amount to be the urea consumption amount, and receiving the second nitrogen oxide concentration value, the urea injection device is controlled to uniformly inject the urea consumption amount within the preset time. After calculating the urea injection amount, the ECU controls the injection pressure of the urea injection unit to uniformly spray a fixed amount of urea solution within the preset time, avoiding fluctuations in the urea solution injection amount from affecting the SCR conversion effect, and thus affecting the SCR conversion efficiency.

[0060] In some embodiments of the present invention, the engine maintains a fixed speed under preset operating conditions. This avoids fluctuations in engine operating conditions from affecting the SCR conversion effect, and thus affecting the SCR conversion efficiency.

[0061] The specific process of the SCR conversion efficiency testing method of the present invention is as follows:

[0062] S1: The vehicle operates under preset conditions. Urea injection is shut off by engine data calibration. After a preset normal operating time, the first nitrogen oxide concentration under this condition is obtained.

[0063] S2: Based on the reaction equation of ammonia and nitrogen oxides, calculate the urea consumption of the engine when urea injection is turned off and the engine runs for a preset time under preset operating conditions.

[0064] S3: Run the vehicle under preset conditions for a preset time, and control the urea injection quantity through engine data. The injection quantity is the urea consumption calculated by S2, and the second nitrogen oxide concentration is obtained.

[0065] S4: Calculate the true conversion efficiency of the SCR chamber according to the formula: (first nitrogen oxide concentration - second nitrogen oxide concentration) / first nitrogen oxide concentration.

[0066] A second aspect of the present invention provides an SCR conversion efficiency testing device, the SCR conversion efficiency testing device comprising:

[0067] The control module is used to control the engine to operate in the states of urea injection off and urea injection on, respectively;

[0068] The acquisition module is used to acquire detection information of the gases discharged from the engine's SCR system;

[0069] The calculation module is used to calculate the true conversion efficiency of SCR based on the detection information.

[0070] The SCR conversion efficiency testing device proposed in the second aspect of the present invention can be a maintenance tool used in the after-sales service of a vehicle. The maintenance tool can be plugged into the control interface of the vehicle and communicate with the ECU. The maintenance tool has a control module, an acquisition module, and a calculation module. The program is pre-stored in the storage medium of the maintenance tool. After being electrically connected to the ECU, it automatically controls the engine to realize the shutdown of urea injection or quantitative injection, as well as the collection of nitrogen oxide concentration and the final calculation, and finally automatically outputs the true conversion efficiency of the SCR system.

[0071] A third aspect of the present invention provides an electronic device comprising: a processor, a memory, and a computer program; wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program including instructions for performing the SCR conversion efficiency testing method proposed in the first aspect of the present invention.

[0072] A fourth aspect of the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the SCR conversion efficiency testing method proposed in the first aspect of the present invention.

[0073] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0074] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, it may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0075] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disks and discs include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of storage media.

[0076] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for testing SCR conversion efficiency, characterized in that, Includes the following steps: Control the engine to shut off urea injection and run it under preset conditions for a preset time, and receive the first detection information of the gas discharged from the SCR system; Control the engine to start urea injection and run it under the preset operating conditions for the preset time, and receive the second detection information of the gas discharged by the SCR system; Calculate the SCR conversion efficiency based on the first detection information and the second detection information; The first detection information includes a first nitrogen oxide concentration value downstream of the SCR system, and the second detection information includes a second nitrogen oxide concentration value downstream of the SCR system. The step of controlling the engine to start urea injection and operate under the preset conditions for the preset time, and receiving the second detection information of the gas discharged from the SCR system includes: Calculate the urea consumption of the engine during the preset operating condition for the preset time; The engine is controlled to run under the preset operating conditions for the preset time, urea injection is activated and the urea injection amount is controlled to be the urea consumption amount, and the second nitrogen oxide concentration value is received.

2. The SCR conversion efficiency testing method according to claim 1, characterized in that, The step of calculating the SCR conversion efficiency based on the first detection information and the second detection information includes: The SCR conversion efficiency is calculated according to the formula C=(AB) / A, where A is the concentration of the first nitrogen oxide, B is the concentration of the second nitrogen oxide, and C is the SCR conversion efficiency.

3. The SCR conversion efficiency testing method according to claim 2, characterized in that, The first nitrogen oxide concentration value and the second nitrogen oxide concentration value are obtained by monitoring a nitrogen oxide concentration sensor located downstream of the SCR system. Both the first nitrogen oxide concentration value and the second nitrogen oxide concentration value are the average nitrogen oxide concentration values ​​monitored by the nitrogen oxide concentration sensor within the preset time period.

4. The SCR conversion efficiency testing method according to claim 1, characterized in that, In the steps of controlling the engine to run under the preset operating conditions for the preset time, starting urea injection and controlling the urea injection amount to be the urea consumption amount, and receiving the second nitrogen oxide concentration value, the urea injection device is controlled to uniformly inject the urea consumption amount within the preset time.

5. The SCR conversion efficiency testing method according to any one of claims 1 to 4, characterized in that, Under the preset operating conditions, the engine is maintained at a fixed speed.

6. An SCR conversion efficiency testing apparatus, used to implement the SCR conversion efficiency testing method according to any one of claims 1 to 5, characterized in that, The SCR conversion efficiency testing device includes: The control module is used to control the engine to operate in the states of urea injection off and urea injection on, respectively; The acquisition module is used to acquire detection information of the gas discharged from the SCR system of the engine; The calculation module is used to calculate the true conversion efficiency of SCR based on the detection information.

7. An electronic device, characterized in that, include: A processor, a memory, and a computer program; wherein the computer program is stored in the memory and configured to be executed by the processor, the computer program including instructions for performing the SCR conversion efficiency testing method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the SCR conversion efficiency testing method as described in any one of claims 1-5.

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