Non-road four-stage SCR (Selective Catalytic Reduction) system crystal removal method and computer equipment

Abstract

The invention discloses a non-road four-stage SCR system crystal removal method and computer equipment. The method comprises the steps that S1, an SCR system is set to trigger an RGN mode once every T periods; s2, before the SCR system triggers any RGN mode, entering a Desof mode which is not less than 3 times; s3, after the Desof mode is triggered and before the RGN mode is triggered, by adjusting the opening degree of the TVA, the air inflow is reduced, the rail pressure is reduced, and combustion parameters are adjusted, so that the exhaust temperature of the engine is increased; s4, the engine exhaust temperature is in negative correlation with the SOF simulation value, and when the SOF simulation value is lower than a set threshold value, the Desof mode is quitted; and S5, after the current Desof mode exits, continuously accumulating the SOF simulation value until the triggering condition of the next Desof mode is reached, and repeating the steps until the SCR system enters the RGN mode. Through dual guarantee of the RGN mode and the Desof mode, the risk of crystallization is reduced to the minimum, and the pressure of the problems of crystallization / calculus / blockage and the like caused by post-treatment is effectively relieved.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal removal of SCR systems, and in particular to a non-road four-stage SCR system crystal removal method and computer equipment. Background Art

[0002] After a long period of operation, the mixer of the SCR system of a non-road Stage IV vehicle will be at risk of crystallization. In severe cases, the mixer may be blocked, causing increased exhaust back pressure, which will affect both the conversion efficiency of the SCR system and the power of the vehicle.

[0003] In the prior art, the mainstream method of removing crystals is to use active regeneration and high temperature to remove crystals. Active regeneration is to decompose the crystals in the mixer through high-temperature airflow. This method has certain risks in actual operation. The off-road regeneration interval is long and a large amount of crystals are easily accumulated. In addition, it may not work normally due to some uncertain factors. In this way, the crystals cannot be decomposed regularly, which leads to the formation of crystal stones, causing the mixer to be blocked and affecting the operation of the whole vehicle. Summary of the invention

[0004] The present invention provides a non-road four-stage SCR system crystal removal method and computer equipment that effectively improves the removal efficiency of crystal stone blockage and other problems, which can solve at least one of the above-mentioned technical problems.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: a non-road four-stage SCR system crystal removal method, comprising the following steps: S1: Set the SCR system to trigger the RGN mode every T period; S2: Before the SCR system triggers any RGN mode, it enters the Desof mode for no less than 3 times. The triggering condition of the Desof mode is that the accumulation rate of the SOF simulation value reaches the set threshold. The working duration of the Desof mode is t1. S3: Between the triggering of Desof mode and the triggering of RGN mode, the intake air volume is reduced by adjusting the TVA opening, the rail pressure is lowered, and the combustion parameters are adjusted to increase the engine exhaust temperature so that the exhaust temperature of the main operating condition of the engine reaches the ignition temperature of the oxidation catalyst DOC; S4: The engine exhaust temperature is negatively correlated with the SOF simulation value. When the SOF simulation value is lower than the set threshold, the Desof mode is exited; S5: After the current Desof mode is exited, the SOF simulation value continues to accumulate until the trigger condition for the next Desof mode is reached. The cycle is repeated until the SCR system reaches the set condition threshold and enters the RGN mode.

[0006] Furthermore, in the SCR system, the RGN mode and the Desof mode are two independent working modes that do not interfere with each other, and both have the ability to enter and exit spontaneously and autonomously. The RGN mode is an active regeneration mode, and the Desof mode is a passive regeneration mode.

[0007] Furthermore, in S1, the RGN mode is triggered by a timer program of an ECU software module in the SCR system.

[0008] Furthermore, in S1 or S5, the triggering condition of the RGN mode is the back pressure feedback of the diesel particulate filter DPF or a fixed time period. As the vehicle aftertreatment back pressure or the regeneration timer gradually increases and reaches the threshold of the calibration development stage or the set time threshold, the SCR system requests to enter the RGN mode.

[0009] Furthermore, after the RGN mode is triggered, the back pressure of the diesel particulate filter DPF gradually decreases, and the regeneration timer is gradually reset until the SCR system determines that the regeneration operation of the current RGN mode is completed, and then exits the current RGN mode. At this time, the back pressure of the diesel particulate filter DPF gradually increases with the operation of the whole vehicle, and the regeneration timer starts to accumulate again until the next RGN mode is triggered, and the cycle is repeated.

[0010] Furthermore, in S2 or S5, the working cycle, use frequency and duration t1 of the Desof mode are adjusted according to the vehicle type, mixer structure or urea injection amount.

[0011] Furthermore, it also includes S6: verifying the crystal removal effect of the Desof mode, and S6 further includes: S61. Turn on the vehicle regeneration function or the bench regeneration function. When the temperature sensor at the inlet of the diesel particulate filter DPF detects that the temperature reaches A°C and remains stable for t2 time, exit the regeneration function, stabilize at a low load condition, reduce the temperature of the oxidation catalyst DOC, and wait until the temperature sensor detects that the temperature drops below B°C, return to the idle and stop condition, A>B, remove the mixer and weigh it to obtain the current mixer weight M1, and reinstall the mixer after the weighing is completed; S62, driving the vehicle normally, modifying the processing data to increase the urea injection amount by 30% on the original basis to accelerate the formation of crystals, and after the injection continues for t3 time, crystals are formed inside the mixer, and the mixer is removed for weighing, and the current mixer weight is obtained as M2. After weighing, the mixer is reinstalled, and M2-M1 is the weight of the crystals; S63, dismantle and weigh the mixer before entering the Desof mode to obtain a mixer weight M3, reinstall the mixer after weighing, manually enter the Desof mode by modifying the data in the ECU software module, and continue to work for t1 time, then exit the Desof mode and enter normal operation, stop and weigh the weight of the currently disassembled mixer to obtain M4, reinstall the mixer after weighing, and M3-M4 is the weight of the consumed crystals; S64. Compare the proportion of the value of M3-M4 in the value of M2-M1 and calculate the crystal removal rate.

[0012] Furthermore, in S3, the engine exhaust temperature is detected and collected by a temperature sensor installed on the oxidation catalyst DOC.

[0013] Furthermore, in S3, the temperature sensor detects the engine exhaust temperature corresponding to different gears on the vehicle.

[0014] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above-mentioned crystal removal method.

[0015] The beneficial effects of the present invention are embodied in: 1. Based on the traditional regeneration strategy, the present invention proposes a new calibration strategy that combines active and passive methods. That is, during the long-term operation of the whole vehicle, the Desof mode is interspersed several times in the driving regeneration cycle. Compared with the monotonous regeneration strategy of the traditional strategy, there is both the driving regeneration RGN mode that increases the exhaust temperature through active regeneration to remove crystallization, and the Desof mode that increases the exhaust temperature through passive regeneration to reduce crystallization inside the mixer.

[0016] 2. The present invention reduces the risk of crystallization to a minimum through the dual protection of RGN mode and Desof mode, and can effectively alleviate the pressure of post-processing problems such as crystallization / stones / blockage.

[0017] 3. In the present invention, the RGN mode and the Desof mode are independent of each other and do not interfere with each other. Both modes can be entered or exited spontaneously, which can extend the use cycle of parking regeneration and allow the entire vehicle to spontaneously clear crystals during normal operation, which is more convenient and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0019] Figure 1It is a schematic diagram of the overall process of the crystal removal method according to an embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram comparing the processes of the crystal removal method proposed in the embodiment of the present invention and the crystal removal method proposed under the traditional strategy.

[0021] Figure 3 It is a schematic diagram of the consumption rate of the SOF simulation value according to an embodiment of the present invention.

[0022] Figure 4 It is a performance diagram of the engine exhaust temperature of the whole vehicle at different gears in the Desof mode of an embodiment of the present invention.

[0023] Figure 5 It is a structural block diagram of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that the meaning of “and / or” appearing in the full text includes three parallel solutions. Taking “A and / or B” as an example, it includes Solution A, Solution B, or a solution in which both A and B are satisfied.

[0026] See also Figure 1 The embodiment of the present invention provides a non-road four-stage SCR system crystal removal method, comprising the following steps: S1: Set the SCR system to trigger the RGN mode once every T period, and the time period T is generally set to 100 hours; S2: Before the SCR system triggers any RGN mode, it enters the Desof mode for no less than 3 times. The triggering condition of the Desof mode is that the accumulation rate of the SOF simulation value reaches the set threshold. The working duration of the Desof mode is t1, which is generally set to 20 minutes. S3: Between the triggering of Desof mode and the triggering of RGN mode, measures such as reducing the intake volume by adjusting the TVA opening, lowering the rail pressure, and adjusting the combustion parameters are taken to increase the engine exhaust temperature so that the exhaust temperature of the main operating condition of the engine reaches the ignition temperature of the oxidation catalyst DOC. The ignition temperature is generally set to be above 250°C, and is often set to 400°C. A large number of tests in the past have proved that when the engine exhaust temperature reaches 350°C, there will be a significant effect of clearing crystals; S4: The engine exhaust temperature is negatively correlated with the SOF simulation value. The rate at which the SOF simulation value is consumed can be calibrated according to different temperatures. The higher the engine exhaust temperature, the faster the SOF simulation value is consumed. The Desof mode is exited until the SOF simulation value is lower than the calibrated value for exiting the mode. S5: After the current Desof mode is exited, the SOF simulation value continues to accumulate until the trigger condition of the next Desof mode is reached. The cycle is repeated until the SCR system reaches the set condition threshold and enters the RGN mode. The condition threshold includes the back pressure threshold of the diesel particulate filter DPF and the time threshold of the fixed period.

[0027] Based on the traditional regeneration strategy, the present invention proposes a new calibration strategy that combines active and passive methods. That is, during the long-term operation of the whole vehicle, the Desof mode is interspersed several times in the driving regeneration cycle. Compared with the monotonous regeneration strategy of the traditional strategy, there is both the RGN mode of driving regeneration to increase the exhaust temperature through active regeneration to remove crystallization, and the Desof mode to increase the exhaust temperature through passive regeneration to reduce crystallization inside the mixer.

[0028] See also Figure 1-Figure 2 In this embodiment, in the SCR system, the RGN mode and the Desof mode are two independent working modes that do not interfere with each other, and both have the ability to enter and exit spontaneously and autonomously. The RGN mode is an active regeneration mode, and the Desof mode is a passive regeneration mode.

[0029] See also Figure 1-Figure 2 In this embodiment, in S1, the RGN mode is triggered by the timer program of the ECU software module in the SCR system. After the ECU software module controls the injection, the diesel passes through the oxidation catalyst DOC together with the exhaust gas, releasing heat, and the exhaust temperature rises sharply to about 600°C. The high-temperature airflow passes through the mixer to decompose the crystallized material in the mixer.

[0030] See also Figure 1-Figure 2In this embodiment, in S1 or S5, the triggering condition of the RGN mode is the back pressure feedback of the diesel particulate filter DPF or a fixed time period. As the vehicle aftertreatment back pressure or the regeneration timer gradually increases and reaches the threshold of the calibration development stage or the set time threshold, the SCR system requests to enter the RGN mode; After the RGN mode is triggered, the back pressure of the diesel particulate filter DPF gradually decreases, and the regeneration timer is gradually reset until the SCR system determines that the regeneration operation of the current RGN mode is completed, and then exits the current RGN mode. At this time, the back pressure of the diesel particulate filter DPF gradually increases with the operation of the whole vehicle, and the regeneration timer starts to accumulate again until the next RGN mode is triggered, and the cycle is repeated.

[0031] After the vehicle enters the RGN mode, the exhaust temperature will increase to about 600°C, but the cycle for triggering the RGN mode is too long, which places great demands on the performance of post-processing. Some extreme working environments of the whole vehicle are prone to rapid accumulation of crystals, but the back pressure or time at this time does not reach the threshold for triggering regeneration, and it is very likely that the crystals will accumulate more and more, resulting in malfunctions such as nozzle blockage. As described in the previous embodiment, the RGN mode is triggered by the time timer program of the ECU software module. For example, if it is set to be triggered every 100 hours, before triggering the RGN mode, the probability of crystal accumulation can be reduced by fixing the Desof mode multiple times (generally set to 3 times or at least 3 times).

[0032] See also Figure 1-Figure 3 In this embodiment, in S2 or S5, the working cycle, use frequency and duration t1 of the Desof mode are adjusted according to the vehicle model, mixer structure or urea injection amount. The use frequency of the Desof mode can be increased according to different vehicle models, such as once every 26 hours, each time for 20 minutes. If the mixer structure is unreasonable or the urea injection amount is excessive, it is more likely to cause crystallization problems. At this time, it can be considered to increase the use frequency and duration of the Desof mode.

[0033] In the present application, the Desof mode is a separate passive regeneration mode different from the RGN mode. The value of the variable OxiCat_rLoad is used to represent the size of the SOF simulation value on the ECU software module. OxiCat_rLoad starts from an initial value of 0 and increases at a certain rate. The growth rate is determined by the value in OxiCat_dmHcEgr_MAP. For example, if the value 0.04 is filled in OxiCat_dmHcEgr_MAP, the growth rate of SOF is 0.04 mg / s. When OxiCat_rLoad reaches the OxiCat_rLoadRgnThres_C threshold, the Desof mode is triggered. If OxiCat_rLoad increases at a fixed rate of 0.04 mg / s and the OxiCat_rLoadRgnThres_C value is set to 3.8 g, it will take about 26 hours to reach the set threshold OxiCat_rLoadRgnThres_C, at which time the Desof mode can be triggered; After the Desof mode is triggered, the exhaust temperature of the engine is increased by adjusting the TVA opening to reduce the intake volume, lowering the rail pressure, and adjusting the combustion parameters, so that the exhaust temperature of the main operating conditions of the engine can reach above 400°C, which can effectively remove crystals. The temperature can be detected by the temperature sensor on the oxidation catalyst DOC, such as Figure 3 As shown, OxiCat_dmHcRgn_CUR can control the consumption rate of the SOF simulation value. The post-processing is equipped with a temperature sensor. The measured temperature value can be used as the input value of the X-axis temperature. The ordinate is the consumption rate of the SOF simulation value after entering the Desof mode (modifiable), and the unit is g / s. Different SOF consumption rates are obtained according to different temperature intervals to consume the SOF simulation value. Figure 3 When the temperature reaches 350℃, the SOF consumption rate is 0.001g / s. When the temperature reaches 390℃, the consumption rate is 0.004g / s. A large number of tests have proven that the temperature sensor on the oxidation catalyst DOC has a significant effect on removing crystals when the temperature reaches 350°C, and the engine exhaust temperature reaches more than 400°C to remove crystals more effectively. The SOF simulation value OxiCat_rLoad enters the Desof mode after reaching the threshold value 3.8g, and then reduces the value of OxiCat_rLoad through a certain SOF consumption rate until OxiCat_rLoad drops to the set value of the variable OxiCat_rLoadSuc_C. For example, if the set value of OxiCat_rLoadSuc_C is 0, that is, the SOF simulation value drops to 0, and then exits the Desof mode. After exiting the Desof mode, the SOF simulation value continues to increase until it reaches the threshold again, and such operations are repeated.

[0034] See also Figure 1-Figure 3 In this embodiment, it also includes S6: verifying the crystal removal effect of the Desof mode, and S6 further includes: S61. Turn on the vehicle regeneration function or the bench regeneration function. When the temperature sensor at the inlet of the diesel particulate filter DPF detects that the temperature reaches A℃ and remains stable for t2 minutes, t2 is generally set to 40 minutes. Exit the regeneration function and stabilize at a low load condition. Reduce the temperature of the oxidation catalyst DOC. When the temperature sensor detects that the temperature drops below B℃, return to the idle and shutdown condition. A>B. Generally, A℃ is set to 600℃ and B℃ is set to 300℃. Remove the mixer and weigh it to obtain the current mixer weight M1. After weighing, reinstall the mixer. S62, driving the vehicle normally, modifying the processing data to increase the urea injection amount by 30% on the original basis to accelerate the formation of crystals, and continuing the injection for t3 time, generally setting t3 to 10 hours, to form crystals inside the mixer, dismantling the mixer for weighing, and obtaining the current mixer weight as M2. After weighing, reinstall the mixer, and M2-M1 is the weight of the crystals; S63, dismantle and weigh the mixer before entering the Desof mode to obtain the mixer weight M3, reinstall the mixer after weighing, manually enter the Desof mode by modifying the data in the ECU software module, and continue to work for t1 time, that is, after 20 minutes of operation, the vehicle exits the Desof mode and enters normal operation, stops and weighs the weight of the currently disassembled mixer to be M4, reinstalls the mixer after weighing, and M3-M4 is the weight of the consumed crystals; S64. Compare the proportion of the value of M3-M4 in the value of M2-M1 and calculate the crystal removal rate.

[0035] The crystal removal rate after the current Desof mode is obtained by calculation, the crystal removal effect of the Desof mode is judged, and the various parameter indicators of the next Desof mode are adjusted according to the crystal removal effect of this time to achieve a better crystal removal level.

[0036] See also Figure 4 In this embodiment, in S3, the engine exhaust temperature is detected and collected by a temperature sensor installed on the oxidation catalyst DOC; The temperature sensor detects the engine exhaust temperature corresponding to different gears on the vehicle.

[0037] The engine exhaust temperature of gears 1 to 6 was tested on the whole vehicle respectively. It can be seen from the data records that the exhaust temperature can generally reach above 400°C and can automatically enter or exit the Desof mode.

[0038] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the above method.

[0039] See also Figure 5 An embodiment of the present invention further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0040] The embodiment of the present invention further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the steps of the above method.

[0041] It is understandable that the system, device and storage medium provided in the embodiments of the present invention correspond to the method provided in the embodiments of the present invention, and the explanation, examples and beneficial effects of the relevant contents can refer to the corresponding parts in the above methods.

[0042] It should be noted that those skilled in the art can understand that all or part of the steps implemented in the embodiments of the present invention can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using hardware, it can be implemented in whole or in part in the form of purchased standard parts or modified parts. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0043] In summary, the present invention proposes a new calibration strategy that combines active and passive methods based on the traditional regeneration strategy. That is, during long-term operation of the whole vehicle, the Desof mode is interspersed several times in the driving regeneration cycle. Compared with the monotonous regeneration strategy of the traditional strategy, there is both the RGN mode of driving regeneration to increase the exhaust temperature through active regeneration to remove crystallization, and the Desof mode to increase the exhaust temperature through passive regeneration to reduce crystallization inside the mixer.

[0044] In the present invention, the risk of crystallization is minimized through the dual protection of RGN mode and Desof mode, which can effectively alleviate the pressure of post-processing problems such as crystallization / stones / blockage. The two modes are independent of each other and do not interfere with each other. Both modes can enter or exit spontaneously, which can extend the use cycle of parking regeneration and allow the entire vehicle to spontaneously clear crystals during normal operation, which is more convenient and practical.

[0045] It should be understood that the examples and implementation modes described herein are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art may make various modifications or changes based on the examples and implementation modes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A non-road four-stage SCR system crystal removal method, characterized in that: The following steps are involved: S1: Set the SCR system to trigger the RGN mode every T period; S2: Before the SCR system triggers any RGN mode, it enters the Desof mode for no less than 3 times. The triggering condition of the Desof mode is that the accumulation rate of the SOF simulation value reaches the set threshold. The working duration of the Desof mode is t1. S3: Between the triggering of Desof mode and the triggering of RGN mode, the intake air volume is reduced by adjusting the TVA opening, the rail pressure is lowered, and the combustion parameters are adjusted to increase the engine exhaust temperature so that the exhaust temperature of the main operating condition of the engine reaches the ignition temperature of the oxidation catalyst DOC; S4: The engine exhaust temperature is negatively correlated with the SOF simulation value. When the SOF simulation value is lower than the set threshold, the Desof mode is exited; S5: After the current Desof mode is exited, the SOF simulation value continues to accumulate until the trigger condition for the next Desof mode is reached. The cycle is repeated until the SCR system reaches the set condition threshold and enters the RGN mode.

2. The non-road four-stage SCR system crystal removal method according to claim 1, characterized in that: In the SCR system, the RGN mode and the Desof mode are two independent working modes that do not interfere with each other, both of which have the ability to enter and exit spontaneously and autonomously. The RGN mode is an active regeneration mode, and the Desof mode is a passive regeneration mode.

3. The non-road four-stage SCR system crystal removal method according to claim 1, characterized in that: In S1, the RGN mode is triggered by a timer program of an ECU software module in the SCR system.

4. The non-road four-stage SCR system crystal removal method according to claim 3, characterized in that: In S1 or S5, the triggering condition of the RGN mode is the back pressure feedback of the diesel particulate filter DPF or a fixed time period. As the vehicle aftertreatment back pressure or the regeneration timer gradually increases and reaches the threshold of the calibration development stage or the set time threshold, the SCR system requests to enter the RGN mode.

5. The non-road four-stage SCR system crystal removal method according to claim 4, characterized in that: After the RGN mode is triggered, the back pressure of the diesel particulate filter DPF gradually decreases, and the regeneration timer is gradually reset until the SCR system determines that the regeneration operation of the current RGN mode is completed, and then exits the current RGN mode. At this time, the back pressure of the diesel particulate filter DPF gradually increases with the operation of the whole vehicle, and the regeneration timer starts to accumulate again until the next RGN mode is triggered, and the cycle is repeated.

6. The non-road four-stage SCR system crystal removal method according to claim 1, characterized in that: In S2 or S5, the working cycle, use frequency and duration t1 of the Desof mode are adjusted according to the vehicle type, mixer structure or urea injection amount.

7. The non-road four-stage SCR system crystal removal method according to claim 1, characterized in that: The method further comprises S6: verifying the crystal removal effect of the Desof mode, wherein S6 further comprises: S61. Turn on the vehicle regeneration function or the bench regeneration function. When the temperature sensor at the inlet of the diesel particulate filter DPF detects that the temperature reaches A°C and remains stable for t2 time, exit the regeneration function, stabilize at a low load condition, reduce the temperature of the oxidation catalyst DOC, and wait until the temperature sensor detects that the temperature drops below B°C, return to the idle and stop condition, A>B, remove the mixer and weigh it to obtain the current mixer weight M1, and reinstall the mixer after the weighing is completed; S62, driving the vehicle normally, modifying the processing data to increase the urea injection amount by 30% on the original basis to accelerate the formation of crystals, and after the injection continues for t3 time, crystals are formed inside the mixer, and the mixer is removed for weighing, and the current mixer weight is obtained as M2. After weighing, the mixer is reinstalled, and M2-M1 is the weight of the crystals; S63, dismantle and weigh the mixer before entering the Desof mode to obtain a mixer weight M3, reinstall the mixer after weighing, manually enter the Desof mode by modifying the data in the ECU software module, and continue to work for t1 time, then exit the Desof mode and enter normal operation, stop and weigh the weight of the currently disassembled mixer to obtain M4, reinstall the mixer after weighing, and M3-M4 is the weight of the consumed crystals; S64. Compare the proportion of the value of M3-M4 in the value of M2-M1 and calculate the crystal removal rate.

8. The non-road four-stage SCR system crystal removal method according to claim 1, characterized in that: In S3, the engine exhaust temperature is detected and collected by a temperature sensor installed on the oxidation catalyst DOC.

9. The non-road four-stage SCR system crystal removal method according to claim 8, characterized in that: In S3, the temperature sensor detects the engine exhaust temperature corresponding to different gears on the vehicle.

10. A computer device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 9.

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