Urea detection method, device and system applied to aftertreatment system

Abstract

The invention discloses a urea detection method, device and system applied to a post-processing system, and belongs to the field of diesel engine post-processing systems.The method comprises the steps that a urea quality value and a urea consumption value are obtained, when the urea quality value and the urea consumption value reach a urea quality alarm threshold value, an alarm signal is generated and forwarded to a cloud platform server, and the urea consumption value is synchronously and continuously uploaded; opening a urea injection valve based on the alarm signal; after the urea injection valve is opened, obtaining a nitrogen oxide concentration value; if the nitrogen oxide concentration value reaches the preset nitrogen oxide threshold value, a three-way electromagnetic valve is started for sampling, and a urea pump is started for working; stopping and synchronously closing the urea pump after the sampling of the three-way electromagnetic valve reaches a preset time, and marking the urea sample as a full bottle state; a sampling signal is generated based on the full bottle state and is used for inspecting the urea in the sampling bottle and judging whether the low-quality urea is qualified or not. According to the invention, urea sampling starting is automatically controlled, and high-precision and real-time detection of urea quality and urea consumption is realized at the same time.

Description

Technical Field

[0001] The invention belongs to the field of non-road diesel engine aftertreatment systems, and in particular relates to a urea detection method, device and system applied to the aftertreatment system. Background Art

[0002] The post-treatment system includes the DOC system, DPF system, and SCR system. The main function of the SCR system is that under the action of the catalyst, ammonia reacts with nitrogen oxides in the engine exhaust to generate harmless ammonia and water. Among them, the urea solution in the urea tank is sprayed into the SCR system through the urea nozzle, and the urea dissolves and undergoes a thermal decomposition reaction to generate ammonia; in this process, the urea consumption of the post-treatment system should be proportional to the content of pollutants emitted by the engine. If the urea consumption is abnormal, it may cause the emission of pollutants to exceed the standard or the post-treatment system may malfunction. Therefore, in order to reduce harmful gases in exhaust emissions and whether the post-treatment system is operating normally, it is necessary to detect the urea consumption of the post-treatment system to avoid excessive or low consumption.

[0003] Secondly, long-term use of low-quality urea will lead to reduced conversion efficiency of the SCR system and increased urea consumption, but traditional urea quality sensors may have false alarms due to insufficient accuracy, and the urea replacement frequency is high, and sampling is time-consuming and labor-intensive. Although the existing diesel engine after-treatment system can detect urea consumption, such as judging whether the urea injection is normal by collecting the urea injection time and the preset injection time, and then further judging the urea consumption by the injection performance of the urea solution; another is to calculate the urea consumption through the nitrogen oxide signal of the NOx sensor, and then further calculate the urea-fuel ratio, and judge whether the urea consumption is abnormal according to the set urea consumption; in addition, there is a technology to judge whether the urea consumption is abnormal by the urea filling amount; although the above three methods can detect urea consumption to a certain extent, they cannot achieve high-precision detection of urea quality. Therefore, the performance of the after-treatment system cannot be fully and effectively evaluated based on the detection result of urea consumption. Summary of the invention

[0004] The purpose of the present invention is to provide a urea detection method, device and system applied to a post-treatment system, which can solve the problems in the background technology, collect urea quality values ​​and urea consumption values ​​for comprehensive judgment, and upload the data to a cloud platform, further continuously calculate and monitor the urea consumption and the quality of urea, automatically control the start of urea sampling, and realize high-precision detection of urea quality and urea consumption at the same time.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0006] In one aspect, the present invention provides a urea detection method applied to a post-treatment system, comprising:

[0007] Obtain urea mass value and urea consumption value;

[0008] When the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is synchronously and continuously uploaded;

[0009] Based on the alarm signal, the urea injection valve is opened;

[0010] When the urea injection valve is opened, the nitrogen oxide concentration value is obtained;

[0011] If the nitrogen oxide concentration reaches the preset nitrogen oxide threshold, the three-way solenoid valve sampling and urea pump operation are started;

[0012] After the three-way solenoid valve samples for a preset time, the urea pump is stopped and closed synchronously, and the urea sampling is marked as a full bottle state;

[0013] A sampling signal is generated based on the full bottle status to send the urea in the sampling bottle for inspection to determine whether the low-quality urea is qualified.

[0014] Optionally, when the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is uploaded synchronously, which also includes:

[0015] The cloud platform obtains the urea consumption value;

[0016] Calculate the ratio of the accumulated urea consumption value within the set time to the fuel consumption value to obtain the urea-fuel ratio data of the set period;

[0017] According to the difference between the urine-fuel ratio of two consecutive cycles and the difference between the historical average urine-fuel ratio and the urine-fuel ratio of the current cycle, the urea consumption abnormality and the urea quality abnormality are obtained and fed back to the ECU;

[0018] If the difference between the urine-fuel ratio of the current cycle and the urine-fuel ratio of the previous cycle is greater than the first threshold percentage, a urea consumption abnormality signal is generated, and if the difference between the urine-fuel ratio of the current cycle and the historical average urine-fuel ratio is greater than the second threshold percentage, a urea quality abnormality signal is generated;

[0019] The abnormal urea consumption signal and the abnormal urea quality signal are sent to the ECU for cyclically obtaining the urea quality value and the urea consumption value.

[0020] Optionally, the calculation expression of the urine-fuel ratio of the current cycle is:

[0021] R1=(U1-U0) / (F1-F0)

[0022] Where r1 is the urea-fuel ratio in the current cycle, f1 is the cumulative fuel consumption in the current cycle, f0 is the cumulative fuel consumption in the previous cycle, u1 is the current cumulative urea consumption, and u1 is the cumulative urea consumption in the previous cycle.

[0023] Optionally, based on the alarm signal, opening the urea injection valve further includes judging the state of the urea injection valve, and if the state of the urea injection valve itself is an open state, maintaining the open state;

[0024] If the urea injection valve is in the closed state, the urea injection valve is opened based on the alarm signal.

[0025] Optionally, generating a sampling signal based on the full bottle status also includes uploading the full bottle status to a cloud platform;

[0026] After the cloud platform receives the full bottle status, it marks the associated vehicle to temporarily suspend sampling until it receives a change in the sampling bottle status and resumes sampling.

[0027] Optionally, marking the urea sampling as a full bottle state also includes using binary to mark the urea sampling state, wherein the full bottle state is "1" and the empty bottle state is "0".

[0028] In a second aspect, the present invention provides a urea detection system for a post-treatment system, comprising:

[0029] Engine ECU, sensor group, urea injection valve, sampling bottle, urea pump, three-way solenoid valve and SCR system;

[0030] The sensor group is used to collect urea mass value and nitrogen oxide concentration value respectively;

[0031] The urea injection valve is connected to the SCR system and is connected to the urea tank via a three-way solenoid valve and a urea pump, and is used for switching between the SCR system and the urea tank;

[0032] The sampling bottle is connected to the urea tank via a three-way solenoid valve and a urea pump, and is used for sampling when the urea quality is abnormal;

[0033] The SCR system is used to generate urea consumption

[0034] The engine ECU is electrically connected to the sensor group, the urea injection valve, the urea pump, the three-way solenoid valve and the SCR system respectively to execute the steps of the above method.

[0035] Optionally, the sensor group includes a urea quality sensor and a nitrogen oxide sensor; wherein the urea quality sensor is installed on the urea tank to directly detect the quality of urea in the urea tank;

[0036] The nitrogen oxide sensor is installed at the outlet of the SCR system to obtain the nitrogen oxide concentration value.

[0037] In a third aspect, the present invention provides a urea detection device applied to a post-treatment system, comprising a data acquisition module, an alarm and upload module, a nitrogen oxide detection module and a sampling module.

[0038] The data acquisition module is used to acquire the urea mass value and the urea consumption value;

[0039] The alarm and upload module is used to generate an alarm signal and forward it to the cloud platform server when the urea quality value reaches the urea quality alarm threshold, and to synchronously and continuously upload the urea consumption value;

[0040] The nitrogen oxide detection module is used to open the urea injection valve based on the alarm signal; when the urea injection valve is opened, the nitrogen oxide concentration value is obtained; if the nitrogen oxide concentration value reaches the preset nitrogen oxide threshold, the three-way solenoid valve sampling is started and the urea pump is turned on;

[0041] The sampling module is used to stop and synchronously close the urea pump after the three-way solenoid valve samples for a preset time, and mark the urea sampling as a full bottle state; based on the full bottle state, a sampling signal is generated to send the urea in the sampling bottle for inspection to obtain a low-quality urea evaluation result.

[0042] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0043] After the post-treatment system issues an early warning, the urea quality value and urea consumption value are collected for comprehensive judgment, and the data is uploaded to the cloud platform to further continuously calculate and monitor the urea consumption and urea quality, automatically control the start of urea sampling, and realize high-precision detection of urea quality and urea consumption at the same time.

[0044] The system structure is streamlined, and the engine ECU can sense the urea quality value and urea consumption value in real time to achieve automatic control of the urea injection valve, sampling bottle, urea pump and three-way solenoid valve, and finally realize automatic sampling and detection of the post-treatment system, and generate early warning information in real time to avoid the risk of excessive product emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flow chart of a urea detection method of the present invention applied to a post-treatment system;

[0046] Figure 2 It is a diagram of an embodiment of the cloud platform data processing of the present invention;

[0047] Figure 3 It is a structural block diagram of a detection device based on the present invention applied to a post-processing system.

[0048] Reference numerals: 1. urea tank, 2. urea quality sensor, 3. urea pump, 4. ECU, 5. three-way solenoid valve, 6. sampling bottle, 7. urea injection valve, 8. SCR system, 9. nitrogen oxide sensor, 10. urea pipe. DETAILED DESCRIPTION

[0049] In order to more fully understand the technical content of the present invention, the technical solution of the present invention is further introduced and illustrated in conjunction with specific embodiments below, but is not limited thereto.

[0050] Example 1

[0051] This embodiment provides a urea detection method applied to a post-treatment system, such as Figure 1 Shown include:

[0052] Step 1, obtaining urea mass value and urea consumption value;

[0053] Step 2: When the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is synchronously and continuously uploaded;

[0054] Step 3: based on the alarm signal, opening the urea injection valve;

[0055] Step 4: When the urea injection valve is opened, obtain the nitrogen oxide concentration value;

[0056] Step 5: If the nitrogen oxide concentration reaches the preset nitrogen oxide threshold, the three-way solenoid valve is started to sample and the urea pump is turned on;

[0057] Step 6: After the three-way solenoid valve samples for a preset time, the urea pump is stopped and closed synchronously, and the urea sampling is marked as a full bottle state;

[0058] Step 7: Generate a sampling signal based on the full bottle state, which is used to send the urea in the sampling bottle for inspection to determine whether the low-quality urea is qualified.

[0059] Optionally, when the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is uploaded synchronously, such as Figure 2 Also shown are:

[0060] The cloud platform obtains the urea consumption value;

[0061] Calculate the ratio of the accumulated urea consumption value within the set time to the fuel consumption value to obtain the urea-fuel ratio data of the set period;

[0062] According to the difference between the urine-fuel ratio of two consecutive cycles and the difference between the historical average urine-fuel ratio and the urine-fuel ratio of the current cycle, the urea consumption abnormality and the urea quality abnormality are obtained and fed back to the ECU;

[0063] If the difference between the urine-fuel ratio of the current cycle and the urine-fuel ratio of the previous cycle is greater than the first threshold percentage, a urea consumption abnormality signal is generated, and if the difference between the urine-fuel ratio of the current cycle and the historical average urine-fuel ratio is greater than the second threshold percentage, a urea quality abnormality signal is generated;

[0064] The abnormal urea consumption signal and the abnormal urea quality signal are sent to the ECU for cyclically obtaining the urea quality value and the urea consumption value.

[0065] Optionally, the calculation expression of the urine-fuel ratio of the current cycle is:

[0066] R1=(U1-U0) / (F1-F0)

[0067] Where r1 is the urea-fuel ratio in the current cycle, f1 is the cumulative fuel consumption in the current cycle, f0 is the cumulative fuel consumption in the previous cycle, u1 is the current cumulative urea consumption, and u1 is the cumulative urea consumption in the previous cycle.

[0068] In this embodiment, every T hours, the urea consumption (u1-u0) in the cycle is calculated, and the ratio of the fuel consumption (f1-f0) in the cycle is obtained to obtain the urea-fuel ratio r1 in the cycle. The urea-fuel ratio r2 of the next cycle is calculated by the same method, r2=(u2-u1) / (f2-f1). The total urea-fuel ratio data is Rt=Ut / Ft. It is the ratio of the total urea consumption to the total fuel consumption. If the difference between the urea-fuel ratio of the current cycle and the urea-fuel ratio of the previous cycle is greater than a%, it is considered that the urea consumption is abnormal. At this time, it is compared with the historical urea-fuel ratio. If the difference is greater than b%, the urea quality abnormality signal is output to the ECU.

[0069] Optionally, based on the alarm signal, opening the urea injection valve further includes judging the state of the urea injection valve, and if the state of the urea injection valve itself is an open state, maintaining the open state;

[0070] If the urea injection valve is in the closed state, the urea injection valve is opened based on the alarm signal.

[0071] Optionally, generating a sampling signal based on the full bottle status also includes uploading the full bottle status to a cloud platform;

[0072] After the cloud platform receives the full bottle status, it marks the associated vehicle to temporarily suspend sampling until it receives a change in the sampling bottle status and resumes sampling.

[0073] Optionally, marking the urea sampling as a full bottle state also includes using binary to mark the urea sampling state, wherein the full bottle state is "1" and the empty bottle state is "0".

[0074] Example 2

[0075] This embodiment provides a urea detection system 8 applied to a post-processing system 8, such as Figure 3 Shown include:

[0076] Engine ECU 4, sensor group, urea injection valve 7, sampling bottle 6, urea pump 3, three-way solenoid valve 5 and SCR system 8;

[0077] The sensor group is used to collect urea mass value and nitrogen oxide concentration value respectively;

[0078] The urea injection valve 7 is connected to the SCR system 8 and is connected to the urea tank 1 through the three-way solenoid valve 5 and the urea pump 3, and is used for switching between the SCR system 8 and the urea tank 1;

[0079] The sampling bottle 6 is connected to the urea tank 1 through a three-way solenoid valve 5 and a urea pump 3, and is used for sampling when the urea quality is abnormal;

[0080] The SCR system 8 is used to generate urea consumption

[0081] The engine ECU 4 is electrically connected to the sensor group, the urea injection valve 7 , the urea pump 3 , the three-way solenoid valve 5 and the SCR system 8 respectively to execute the steps of the above method.

[0082] Optionally, the sensor group includes a urea quality sensor 2 and a nitrogen oxide sensor 9; wherein the urea quality sensor 2 is installed on the urea tank 1, and is used to directly detect the quality of urea in the urea tank 1;

[0083] The nitrogen oxide sensor 9 is installed at the outlet of the SCR system 8 to obtain the nitrogen oxide concentration value.

[0084] In this embodiment, the urea tank 1 is connected to other accessories through the urea pipe 10 to provide urea to the sampling bottle 6 and the SCR system 8. The ECU 4 records the state of the sampling bottle 6 and uploads the state to the cloud platform. If the bottle is full, sampling cannot continue. The service personnel can count the vehicle numbers according to the state of the sampling bottle 6 and determine the vehicle number for the next sampling, thereby omitting the manual investigation process and reducing the personnel maintenance cost.

[0085] Example 3

[0086] This embodiment provides a urea detection device applied to a post-treatment system, including a data acquisition module, an alarm and upload module, a nitrogen oxide detection module and a sampling module.

[0087] The data acquisition module is used to acquire the urea mass value and the urea consumption value;

[0088] The alarm and upload module is used to generate an alarm signal and forward it to the cloud platform server when the urea quality value reaches the urea quality alarm threshold, and to synchronously and continuously upload the urea consumption value;

[0089] The nitrogen oxide detection module is used to open the urea injection valve based on the alarm signal; when the urea injection valve is opened, the nitrogen oxide concentration value is obtained; if the nitrogen oxide concentration value reaches the preset nitrogen oxide threshold, the three-way solenoid valve sampling is started and the urea pump is turned on;

[0090] The sampling module is used to stop and synchronously close the urea pump after the three-way solenoid valve samples for a preset time, and mark the urea sampling as a full bottle state; based on the full bottle state, a sampling signal is generated to send the urea in the sampling bottle for inspection to obtain a low-quality urea evaluation result.

[0091] In summary, after the post-treatment system issues an early warning, the present invention collects urea quality values ​​and urea consumption values ​​for comprehensive judgment, uploads the data to the cloud platform, further calculates the urea consumption, and controls the start of urea sampling, thereby achieving high-precision detection of urea quality and urea consumption at the same time.

[0092] The system structure is streamlined, and the engine ECU can sense the urea quality value and urea consumption value in real time to achieve automatic control of the urea injection valve, sampling bottle, urea pump and three-way solenoid valve, and finally realize automatic sampling and detection of the post-treatment system, and generate early warning information in real time to avoid the risk of excessive product emissions.

[0093] The embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0094] The embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0095] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0098] The above is only a preferred embodiment of the present invention. Without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A urea detection method for a post-treatment system, characterized in that: include: Obtain urea mass value and urea consumption value; When the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is synchronously and continuously uploaded; Based on the alarm signal, the urea injection valve is opened; When the urea injection valve is opened, the nitrogen oxide concentration value is obtained; If the nitrogen oxide concentration reaches the preset nitrogen oxide threshold, the three-way solenoid valve sampling and urea pump operation are started; After the three-way solenoid valve samples for a preset time, the urea pump is stopped and closed synchronously, and the urea sampling is marked as a full bottle state; A sampling signal is generated based on the full bottle status to send the urea in the sampling bottle for inspection to determine whether the low-quality urea is qualified.

2. The urea detection method for a post-treatment system according to claim 1, characterized in that: When the urea quality value reaches the urea quality alarm threshold, an alarm signal is generated and forwarded to the cloud platform server, and the urea consumption value is uploaded synchronously, including: The cloud platform obtains the urea consumption value; Calculate the ratio of the accumulated urea consumption value within the set time to the fuel consumption value to obtain the urea-fuel ratio data of the set period; According to the difference between the urine-fuel ratios of two consecutive cycles and the difference between the historical average urine-fuel ratio and the urine-fuel ratio of the current cycle, the urea consumption abnormality and the urea quality abnormality are obtained and fed back to the ECU.

3. The urea detection method for a post-treatment system according to claim 1, characterized in that: Obtain abnormal urea consumption and urea quality, including: If the difference between the urine-fuel ratio of the current cycle and the urine-fuel ratio of the previous cycle is greater than the first threshold percentage, a urea consumption abnormality signal is generated, and if the difference between the urine-fuel ratio of the current cycle and the historical average urine-fuel ratio is greater than the second threshold percentage, a urea quality abnormality signal is generated; The abnormal urea consumption signal and the abnormal urea quality signal are sent to the ECU for cyclically obtaining the urea quality value and the urea consumption value.

4. The urea detection method for a post-treatment system according to claim 3, characterized in that: The calculation expression of urine-fuel ratio in the current cycle is: ； In the formula, is the urine-to-fuel ratio in the current cycle, is the accumulated fuel consumption in the current cycle, is the accumulated fuel consumption in the previous cycle, is the current accumulated urea consumption, The accumulated urea consumption in the previous cycle.

5. The urea detection method for a post-treatment system according to claim 1, characterized in that: Based on the alarm signal, the urea injection valve is opened, and the state of the urea injection valve is judged, and if the state of the urea injection valve itself is an open state, the urea injection valve is kept open; If the urea injection valve is in the closed state, the urea injection valve is opened based on the alarm signal.

6. The urea detection method for a post-treatment system according to claim 1, characterized in that: generating a sampling signal based on a full bottle status, and also uploading the full bottle status to a cloud platform; After the cloud platform receives the full bottle status, it marks the associated vehicle to temporarily suspend sampling until it receives a change in the sampling bottle status and resumes sampling.

7. The urea detection method for a post-treatment system according to claim 1, characterized in that: Marking the urea sampling as a full bottle state also includes using binary to mark the urea sampling state, wherein the full bottle state is "1" and the empty bottle state is "0".

8. A urea detection system for a post-treatment system, characterized in that: include: Engine ECU, sensor group, urea injection valve, sampling bottle, urea pump, three-way solenoid valve and SCR system; The sensor group is used to collect urea mass value and nitrogen oxide concentration value respectively; The urea injection valve is connected to the SCR system and is connected to the urea tank via a three-way solenoid valve and a urea pump, and is used for switching between the SCR system and the urea tank; The sampling bottle is connected to the urea tank via a three-way solenoid valve and a urea pump, and is used for sampling when the urea quality is abnormal; The SCR system is used to generate urea consumption The engine ECU is electrically connected to the sensor group, the urea injection valve, the urea pump, the three-way solenoid valve and the SCR system respectively to execute the steps of the above method.

9. The urea detection system for a post-treatment system according to claim 8, characterized in that: The sensor group includes a urea quality sensor and a nitrogen oxide sensor; wherein the urea quality sensor is installed on the urea tank and is used to directly detect the quality of urea in the urea tank; The nitrogen oxide sensor is installed at the outlet of the SCR system to obtain the nitrogen oxide concentration value.

10. A urea detection device for a post-treatment system, characterized in that: include: Data acquisition module, alarm and upload module, nitrogen oxide detection module and sampling module; The data acquisition module is used to acquire the urea mass value and the urea consumption value; The alarm and upload module is used to generate an alarm signal and forward it to the cloud platform server when the urea quality value reaches the urea quality alarm threshold, and to synchronously and continuously upload the urea consumption value; The nitrogen oxide detection module is used to open the urea injection valve based on the alarm signal; when the urea injection valve is opened, the nitrogen oxide concentration value is obtained; if the nitrogen oxide concentration value reaches the preset nitrogen oxide threshold, the three-way solenoid valve sampling is started and the urea pump is turned on; The sampling module is used to stop and synchronously close the urea pump after the three-way solenoid valve samples for a preset time, and mark the urea sampling as a full bottle state; based on the full bottle state, a sampling signal is generated to send the urea in the sampling bottle for inspection to obtain a low-quality urea evaluation result.

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