Control method and system for preventing urea nozzle crystallization clogging

Abstract

The application discloses a control method and system for preventing urea nozzle crystallization blockage, wherein the method comprises the following steps: S100, obtaining engine state, ambient temperature, exhaust flow and exhaust temperature; S200, calculating exhaust energy based on the ambient temperature, the exhaust flow and the exhaust temperature; S300, calculating urea rate based on the exhaust energy; S400, judging whether the continuous time of urea stop injection reaches a preset limit value based on the engine state and the exhaust temperature; and S500, if the continuous time of urea stop injection exceeds the preset limit value, spraying urea to the catalyst according to a preset method based on the urea rate. Thus, the control method for preventing urea nozzle crystallization blockage can effectively prevent urea nozzle crystallization blockage, reduce faults, avoid affecting normal operation of the vehicle and additional maintenance costs.

Description

TECHNICAL FIELD

[0001] The embodiment of the application relates to the technical field of engine aftertreatment systems, in particular to a control method and system for preventing crystallization blockage of a urea nozzle. BACKGROUND

[0002] To meet the requirements of the national sixth regulations, vehicle diesel engines inject urea through a catalyst connected to an exhaust pipe. Urea reacts with NOx in the exhaust gas to form N2, achieving compliance with NOx emissions. The urea nozzle is installed on the catalyst and directly contacts the high-temperature engine exhaust. After urea injection is completed, a small amount of urea solution remains in the nozzle's injection hole cavity. Since water has a lower boiling point than urea, water evaporates faster, making it easier to precipitate urea solids and form deposits that block the nozzle. These deposits are called soft crystals. Soft crystals have low hardness, are easily dissolved in water, and are easily decomposed by heat. Soft crystals undergo chemical reactions under high-temperature conditions to form hard crystalline material, known as hard crystals. Hard crystals are difficult to dissolve in water, are not easily decomposed by heat, and have strong mechanical stability. Once formed, they are difficult to remove and can block the nozzle.

[0003] When the engine is idling for a long time or running down a long slope, the exhaust temperature is lower than the urea injection start limit, resulting in long-term urea injection stop. Soft crystals can easily form in the urea nozzle, and hard crystals can form after a certain period of time. A small amount of soft crystals can be hydrolyzed by urea solution, but a large amount of soft crystals or hard crystals can block the nozzle. When the vehicle needs to inject urea, the urea nozzle is blocked and cannot inject urea, causing the diesel engine's NOx emissions to exceed the standard.

[0004] Current methods to prevent urea nozzle crystallization blockage include:

[0005] 1. Increase the slope of the injection hole cavity and shorten the length of the cavity to minimize the amount of urea solution remaining in the cavity.

[0006] 2. Increase the flow of coolant to the urea nozzle to reduce the nozzle temperature and slow down the evaporation rate of the urea solution.

[0007] These two methods have limited effect on reducing nozzle crystallization, and still result in a large number of blockage failures.

[0008] When nozzle crystallization blockage occurs, the current common methods are:

[0009] 1. The user disassembles the urea nozzle and manually cleans the crystalline material from the injection hole. This method delays normal vehicle operation and may not completely clean the crystalline material from the small nozzle hole.

[0010] 2. Directly replace the new urea nozzle. This method delays normal vehicle operation, increases the cost of parts, and cannot completely eliminate the problem. SUMMARY

[0011] The embodiment of the present application provides a control method and system for preventing urea nozzle crystallization blockage, which can effectively prevent urea nozzle crystallization blockage, reduce fault occurrence, avoid affecting normal operation of a vehicle and additional maintenance cost.

[0012] To achieve the above object, in a first aspect, the present application provides a control method for preventing urea nozzle crystallization blockage, comprising:

[0013] Step S100, obtaining engine state, ambient temperature, exhaust flow and exhaust temperature;

[0014] Step S200, calculating exhaust energy based on the ambient temperature, the exhaust flow and the exhaust temperature;

[0015] Step S300, calculating urea rate based on the exhaust energy;

[0016] Step S400, judging whether urea stop spraying continuous time reaches a preset limit value based on the engine state and the exhaust temperature;

[0017] Step S500, if urea stop spraying continuous time exceeds the preset limit value, spraying urea to a catalyst according to a preset method based on the urea rate.

[0018] In an embodiment of the present application, the step S100 comprises:

[0019] Step S101, obtaining engine state after engine power-on;

[0020] Step S102, obtaining the ambient temperature through an ambient temperature sensor;

[0021] Step S103, obtaining the exhaust flow through an exhaust flow sensor;

[0022] Step S104, obtaining the exhaust temperature through an exhaust temperature sensor.

[0023] In an embodiment of the present application, the exhaust energy is calculated based on the ambient temperature, the exhaust flow and the exhaust temperature through a first preset formula, and the first preset formula is:

[0024] Q = ((T1-T2)*E*3.6 / 3600)

[0025] Wherein, Q is the exhaust energy, T1 is the exhaust temperature, T2 is the ambient temperature, and E is the exhaust flow.

[0026] In an embodiment of the present application, the urea rate is calculated based on the exhaust energy through a second preset formula, and the second preset formula is:

[0027] M = a * Q + b

[0028] wherein M is urea that can be pyrolyzed per unit time by exhaust energy, a and b are pyrolysis constants, and Q is exhaust energy.

[0029] In an embodiment of the present application, the step S400 comprises:

[0030] Step S401, judging whether the current is in urea stop injection state based on the engine state and the exhaust temperature;

[0031] Step S402, if the current is in urea stop injection state, starting a timer to record the continuous time of urea stop injection;

[0032] Step S403, continuously updating the timing value of the timer during urea stop injection;

[0033] Step S404, comparing the timing value with a preset limit value to generate a comparison result;

[0034] Step S405, if the comparison result is that the continuous time does not reach the preset limit value, returning to step S403;

[0035] Step S406, if the comparison result is that the continuous time exceeds the preset limit, entering step S500.

[0036] In a second aspect, the present application provides a control system for preventing urea nozzle crystallization blockage, comprising: an acquisition module, a first calculation module, a second calculation module, a judgment module and a spraying module. The acquisition module is configured to acquire engine state, ambient temperature, exhaust flow and exhaust temperature. The first calculation module is configured to calculate exhaust energy based on the ambient temperature, the exhaust flow and the exhaust temperature. The second calculation module is configured to calculate urea rate based on the exhaust energy. The judgment module is configured to judge whether urea stop injection continuous time reaches a preset limit value based on the engine state and the exhaust temperature. The spraying module is configured to spray urea to the catalyst according to a preset method based on the urea rate if the urea stop injection continuous time exceeds the preset limit value.

[0037] In an embodiment of the present application, the acquisition module comprises: a first acquisition unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit. The first acquisition unit is configured to acquire engine state after the engine is powered on. The second acquisition unit is configured to acquire the ambient temperature through an ambient temperature sensor. The third acquisition unit is configured to acquire the exhaust flow through an exhaust flow sensor. The fourth acquisition unit is configured to acquire the exhaust temperature through an exhaust temperature sensor.

[0038] In an embodiment of the present application, the exhaust energy is calculated by a first preset formula based on the ambient temperature, the exhaust flow rate and the exhaust temperature, and the first preset formula is:

[0039] Q = ((T1-T2)*E*3.6 / 3600)

[0040] wherein Q is the exhaust energy, T1 is the exhaust temperature, T2 is the ambient temperature, and E is the exhaust flow rate.

[0041] In a third aspect, the present application provides an electronic device, comprising:

[0042] at least one processor; and

[0043] a memory in communication with the at least one processor;

[0044] wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the control method for preventing crystallization and blockage of a urea nozzle as described above.

[0045] In a fourth aspect, the present application provides a computer-readable storage medium comprising a computer program and instructions, which, when executed on a computer, cause the computer to perform the control method for preventing crystallization and blockage of a urea nozzle as described above.

[0046] Compared with the prior art, the control method and system for preventing crystallization and blockage of a urea nozzle according to the present application can effectively prevent crystallization and blockage of a urea nozzle, reduce the failure rate, ensure normal operation of the vehicle, and reduce maintenance and user costs by adding a cleaning urea nozzle crystallization mode, calculating the urea injection rate in combination with the exhaust energy, and setting reasonable injection intervals and durations. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a flowchart of a control method for preventing crystallization and blockage of a urea nozzle according to an embodiment of the present application;

[0048] Figure 2 is a structural diagram of a control system for preventing crystallization and blockage of a urea nozzle according to an embodiment of the present application;

[0049] Figure 3 is a structural diagram of an electronic device according to an embodiment of the present application;

[0050] Figure 4 is a working logic flowchart of a control method for preventing crystallization and blockage of a urea nozzle according to a specific embodiment of the present application. DETAILED DESCRIPTION

[0051] The embodiments of the present application will be further described below in conjunction with the drawings and examples. It can be understood that the specific embodiments described herein are only used to explain the embodiments of the present application, but not limit the embodiments of the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the embodiments of the present application are shown in the drawings, not all the structures.

[0052] Embodiment one

[0053] Figure 1 is a flowchart of a control method for preventing urea nozzle crystallization blockage in the embodiment one of the present application, as shown in Figure 1 The embodiment one provides a control method for preventing urea nozzle crystallization blockage, applied in an engine control unit (ECU), the method comprising:

[0054] Step S100, obtaining engine state, ambient temperature, exhaust flow and exhaust temperature;

[0055] Specifically, step S100 obtains four key parameters, engine state, ambient temperature, exhaust flow and exhaust temperature, which provides necessary data support for subsequent calculation of exhaust energy, determination of urea injection rate and judgment of whether the continuous time of urea stop injection reaches the preset limit value.

[0056] Step S200, calculating the exhaust energy based on the ambient temperature, the exhaust flow and the exhaust temperature;

[0057] Specifically, through step S200, the accurate exhaust energy value can be obtained, which provides a key basis for subsequent determination of urea injection rate, thereby effectively preventing the occurrence of urea nozzle crystallization blockage.

[0058] Step S300, calculating the urea rate based on the exhaust energy;

[0059] Specifically, according to the calculated exhaust energy, a preset formula or algorithm is used to calculate the amount of urea that can be pyrolyzed per unit time under the current exhaust energy condition, i.e. the urea rate. This urea rate is an important basis for subsequent judgment of whether to inject urea and how much urea to inject. Through this step, urea injection can be ensured at the right time and in the right amount, thereby effectively preventing urea nozzle crystallization blockage.

[0060] Step S400, judging whether the continuous time of urea stop injection reaches the preset limit value based on the engine state and the exhaust temperature;

[0061] Specifically, the engine control unit determines whether the vehicle is in a urea injection stop state based on the current engine state and exhaust temperature, and further calculates the continuous time of urea injection stop. If this continuous time reaches a preset limit, it means that the urea nozzle may be blocked by crystallization due to a long time without injecting urea, and appropriate measures need to be taken to prevent or clear the blockage. This step is important for timely discovering and preventing urea nozzle crystallization blockage and ensuring normal operation of the vehicle.

[0062] Step S500, if the continuous time of urea injection stop exceeds the preset limit, based on the urea rate, urea is injected into the catalyst according to a preset method;

[0063] Specifically, the engine control unit first checks whether the continuous time of urea injection stop exceeds the preset limit. This limit is determined based on system design, emission regulation requirements and experimental data, aiming to balance the relationship between urea consumption, emission performance and system protection. Once it is confirmed that the urea injection stop time exceeds the limit, the system determines the appropriate urea injection rate based on the current engine operating conditions (such as speed, load, exhaust temperature, etc.) and the preset urea injection strategy. This rate needs to ensure that urea can be fully pyrolyzed and react with nitrogen oxides in the exhaust gas, while avoiding waste and potential problems caused by excessive injection. The system will control the operation of the urea pump according to the preset urea injection method (such as injection timing, injection amount control algorithm, etc.) to inject urea solution into the exhaust pipe upstream of the catalyst at a certain rate. This process needs to accurately control the injection timing and injection amount to ensure that urea and nitrogen oxides in the exhaust gas are fully mixed and react. After the urea injection is restored, the system will continuously monitor the conversion efficiency of the catalyst, the exhaust temperature and other parameters, and adjust the urea injection rate in a timely manner according to the actual situation. This helps to optimize the emission performance and ensure the stable operation of the system.

[0064] In a specific embodiment, a diesel vehicle's urea injection system sets the preset limit of urea injection stop time to 10 minutes. During vehicle operation, due to low engine load and insufficient exhaust temperature to support effective urea pyrolysis, the system enters a urea injection stop state. However, due to some reason (such as traffic congestion causing the vehicle to idle for a long time), the urea injection stop time exceeds the preset limit of 10 minutes.

[0065] At this time, the system will perform step S500:

[0066] The system detects that the urea injection stop time exceeds the limit and decides to restore urea injection.

[0067] Based on the current engine speed (assumed to be idle speed), load (very low), and exhaust temperature (which may still be low but is sufficient to support urea pyrolysis), the system determines a low urea injection rate.

[0068] The system activates the urea pump and injects urea solution into the exhaust pipe upstream of the catalyst at a determined rate according to the pre-set injection timing and quantity control algorithm.

[0069] After the urea injection is resumed, the system continues to monitor parameters such as conversion efficiency and exhaust temperature of the catalyst. If the conversion efficiency is found to be unsatisfactory or the exhaust temperature is too high and may damage the catalyst, the system will adjust the urea injection rate in time to optimize emission performance and ensure system safety.

[0070] In this embodiment, the step S100 includes:

[0071] Step S101, after the engine is powered on, the engine state is obtained;

[0072] Specifically, the engine state information generally includes key parameters such as engine speed, load, temperature, etc. These parameters are essential for calculating exhaust energy, urea rate, and judging urea stop injection time, etc. subsequent steps. By obtaining real-time engine state information, the engine control unit can more accurately judge whether there is a risk of crystallization blockage of the urea nozzle and take appropriate preventive measures in time.

[0073] Step S102, obtaining the ambient temperature through an ambient temperature sensor;

[0074] Specifically, ambient temperature is a key parameter because it affects the physical state of urea and injection effect. In low temperature environment, urea is more likely to crystallize, so the system needs to adjust the urea injection strategy according to the ambient temperature to avoid crystallization blockage of the nozzle. When the ambient temperature sensor detects changes in ambient temperature, it will transmit this data to the engine control unit in real time. After receiving the ambient temperature data, the engine control unit will analyze it in combination with other parameters (such as exhaust temperature, exhaust flow, engine speed and load, etc.) to determine the optimal urea injection timing and injection amount.

[0075] Step S103, obtaining the exhaust flow through an exhaust flow sensor;

[0076] Specifically, the exhaust flow sensor is installed in the exhaust system of the engine, which can sense and measure the flow of exhaust gas. When the engine is running, the exhaust flow sensor will continuously collect data and transmit these information to the engine control unit. After receiving the exhaust flow data, the engine control unit will analyze and process it in combination with other parameters (such as exhaust temperature, engine speed and load, etc.) to determine the optimal urea injection timing and injection amount. If the exhaust flow is large, it indicates that the engine is operating at high load, and the system needs to increase the injection amount of urea to ensure that enough urea reacts with nitrogen oxides in the exhaust gas. Conversely, if the exhaust flow is small, the system will reduce the injection amount of urea to avoid the risk of crystallization caused by excessive injection.

[0077] In step S104, the exhaust temperature is obtained by an exhaust temperature sensor.

[0078] Specifically, the exhaust temperature sensor is installed in the exhaust system of the engine to monitor the exhaust temperature in real time. This data is crucial for the development of urea injection control strategy. When the engine is running, the exhaust temperature sensor will continuously collect exhaust temperature data and transmit these data to the engine control unit. After receiving the exhaust temperature data, the engine control unit will analyze and process it to determine the optimal urea injection timing and injection amount. For example, if the exhaust temperature is too high, the system may reduce the injection amount of urea to avoid the rapid decomposition of urea at high temperature and the generation of crystallization. Based on the exhaust temperature data, the engine control unit can also adjust the urea injection strategy in real time to ensure the efficient operation of the urea injection system and the cleanliness of the nozzle.

[0079] In this embodiment, the exhaust energy is calculated based on the ambient temperature, the exhaust flow and the exhaust temperature, and the first preset formula is:

[0080] Q = ((T1-T2)*E*3.6 / 3600)

[0081] Where Q represents the exhaust energy, usually in kilojoules (kJ) or other energy units;

[0082] T1 represents the exhaust temperature, usually in degrees Celsius (℃);

[0083] T2 represents the ambient temperature, also in degrees Celsius (℃);

[0084] E represents the exhaust flow, usually in cubic meters per hour (m 3 / h) or other flow units;

[0085] 3.6 and 3600 are unit conversion coefficients, used to convert the flow unit from cubic meters per hour to cubic meters per second, and the result to kilojoules.

[0086] Specifically, the purpose of this step is to convert the three parameters of ambient temperature, exhaust flow rate, and exhaust temperature into a specific exhaust energy value through a specific mathematical formula, so as to be used for subsequent calculation of urea injection amount or judgment of urea injection timing. For example, assuming that the current state of the exhaust system of a diesel vehicle is as follows: exhaust temperature T1 = 400°C, ambient temperature T2 = 20°C, and exhaust flow rate E = 1000 m 3 / h; these values are substituted into the first preset formula to calculate the exhaust energy:

[0087] Q = ((400-20)*1000*3.6 / 3600)kJ = (380*1000*3.6 / 3600)kJ = 3800kJ;

[0088] Therefore, in the above example, the exhaust energy Q is calculated as 3800kJ. This value can be subsequently used for calculation of urea injection amount, judgment of urea injection timing, or other related control strategy decisions. Through such calculation, the urea injection can be adjusted more accurately according to the current exhaust conditions, thereby optimizing the performance of the urea injection system and reducing the risk of crystallization blockage.

[0089] In this embodiment, the urea rate calculated based on the exhaust energy is obtained through a second preset formula, and the second preset formula is:

[0090] M = a*Q + b

[0091] wherein M represents the amount of urea capable of being pyrolyzed per unit time, and the unit is usually grams (g) or other mass units;

[0092] a and b are pyrolysis constants obtained through experiments or empirical data, which are used to describe the linear relationship between exhaust energy and urea amount in the urea pyrolysis process;

[0093] Q represents the exhaust energy, and the unit is usually kilojoules (kJ) or other energy units, which is calculated through the first preset formula.

[0094] Specifically, the purpose of this step is to determine the amount of urea capable of being effectively pyrolyzed and converted into ammonia per unit time under the current exhaust energy, so as to provide a basis for subsequent calculation of urea injection amount. For example, assuming that the current state of the exhaust system of a diesel vehicle has calculated the exhaust energy Q = 3800kJ through the first preset formula, and the pyrolysis constants a = 0.005g / kJ and b = 1g are known.

[0095] These values are substituted into the second preset formula to calculate the amount of urea capable of being pyrolyzed per unit time:

[0096] M = 0.005 * 3800 + 1 = 19 + 1 = 20 g

[0097] Therefore, in the above example, the amount of urea M that can be pyrolyzed per unit time by exhaust energy is calculated as 20 g. This value can then be used to calculate the actual urea injection amount to ensure that the injected urea can be fully pyrolyzed and converted into ammonia gas in the exhaust system, thereby reacting with nitrogen oxides and reducing emissions. Through such calculation and control, the system can optimize the utilization rate of urea and reduce unnecessary waste and the risk of crystallization blockage.

[0098] In the present embodiment, the step S400 comprises:

[0099] Step S401, judging whether the current is in urea stop injection state based on the engine state and the exhaust temperature;

[0100] Specifically, the engine control unit will first monitor the state parameters of the engine in real time, such as the speed, load, coolant temperature, etc. These parameters reflect the working condition and thermal state of the engine. At the same time, the system will also obtain the exhaust temperature data. The exhaust temperature has an important influence on the pyrolysis of urea and the reaction efficiency with nitrogen oxides. Combined with the engine state and the exhaust temperature, the system will make a judgment according to the pre-set logic or algorithm. These logics or algorithms are usually based on a large amount of experimental data and engineering experience, aiming to determine whether it is suitable to inject urea under the current conditions. If the system judges that the current conditions are not conducive to urea injection (such as too low engine speed, too small load, too low exhaust temperature, etc.), the urea stop injection state will be triggered, and the injection of urea will be suspended.

[0101] In a specific embodiment, for example, a diesel vehicle is running, when the system executes to step S401, the following judgment will be made: the engine speed is 800 rpm (idling state), the load is low; the coolant temperature is 60℃, indicating that the engine has not been fully warmed up; the exhaust temperature is 200℃, which is lower than the temperature threshold required for efficient pyrolysis of urea (usually above 250℃). According to the pre-set logic, the system considers that the current engine speed is low, the load is small, and the exhaust temperature is low, which is not conducive to the pyrolysis of urea and the reaction with nitrogen oxides. Therefore, the system decides to trigger the urea stop injection state and suspend the injection of urea. This can avoid the problem of crystallization blockage caused by injecting urea under low temperature conditions, while saving urea consumption.

[0102] Step S402, if the current is in urea stop injection state, start a timer to record the continuous time of urea stop injection;

[0103] Specifically, when the engine control unit determines that the current situation requires entering the urea injection stop state based on the engine state and exhaust temperature, it starts a timer. This timer will continue running until urea injection is reactivated. The timer records the continuous time of urea injection stop, which is very important for evaluating the performance of the urea system, detecting potential faults, and optimizing the urea injection strategy.

[0104] In a specific embodiment, for example, a diesel vehicle enters the urea injection stop state due to excessively low engine speed and exhaust temperature during operation. At this time, the system will execute step S402, start the timer to record the continuous time of urea injection stop. If the urea injection stop state lasts for 30 minutes, the timer will record this time. During this period, if the engine speed and exhaust temperature return to a level suitable for urea injection, the system will end the urea injection stop state and stop the timer. Then, the system can evaluate the performance of the urea system based on the recorded urea injection stop time, or perform fault diagnosis and emission compliance check.

[0105] Step S403, continuously updating the timer value during the urea injection stop period;

[0106] Specifically, when the system enters the urea injection stop state, a timer is started (as described in step S402). During the urea injection stop period, the system continuously updates the timer value to reflect the real-time duration of urea injection stop. This is usually achieved through the system's internal clock or timer, which increments the timer value at certain time intervals (such as every second).

[0107] In a specific embodiment, for example, a diesel vehicle enters the urea injection stop state due to excessively low engine speed and exhaust temperature. At this time, the system will start the timer and begin recording the duration of urea injection stop. As time passes, as long as the urea injection stop state remains, the system will continuously update the timer value. For example, if the urea injection stop state has lasted for 2 minutes, the timer value will be 120 seconds (assuming the timer is updated in seconds). If during this period, the engine speed and exhaust temperature return to a level suitable for urea injection, the system will end the urea injection stop state and stop the timer. At this time, the timer records the continuous time of urea injection stop, which can be used for subsequent control decisions, fault diagnosis, or emission compliance checks. In general, step S403 ensures that the system can accurately track the duration of urea injection stop, providing important time information for subsequent urea injection control and fault diagnosis.

[0108] Step S404, comparing the timer value with a preset limit value to generate a comparison result;

[0109] Specifically, the system compares the timer-recorded urea injection stop time with a pre-set limit value. This pre-set limit value is set based on system design and emission regulation requirements, and represents a threshold value for urea injection stop time. If the timer value exceeds this pre-set limit value, it means that the urea injection stop time has been too long, and some measures may need to be taken to restore urea injection to ensure emission compliance and normal operation of the system.

[0110] In a specific embodiment, for example, a urea injection system of a diesel vehicle sets a pre-set limit value for urea injection stop time as 5 minutes (i.e. 300 seconds). During vehicle operation, due to some reasons (such as engine speed being too low, exhaust temperature being too low, etc.), the system enters the urea injection stop state and starts the timer. As time goes on, the timer continuously updates the duration of urea injection stop. If during this process, the timer value reaches 301 seconds (i.e. exceeds the pre-set limit value of 5 minutes), the system will perform step S404 to compare the timer value with the pre-set limit value and generate a comparison result. This comparison result will indicate that the urea injection stop time has exceeded the pre-set limit value, and the system may take appropriate control measures based on this result, such as attempting to restore urea injection, recording fault codes or reminding the driver to check, etc. Such design helps to ensure that the urea injection system can resume work at the right time to reduce emission pollution and protect the normal operation of the system.

[0111] Step S405, if the comparison result is that the continuous time does not reach the pre-set limit value, return to step S403;

[0112] Specifically, when the system performs step S404 to compare the timer value with the pre-set limit value, a comparison result will be generated. If this comparison result shows that the continuous time of urea injection stop has not reached the pre-set limit value, then the system will return to step S403 to continue updating the timer value to monitor the duration of urea injection stop.

[0113] In a specific embodiment, a urea injection system of a diesel vehicle is set with a pre-set limit of 10 minutes (i.e. 600 seconds) for the urea injection stop time. During the vehicle operation, the system enters the urea injection stop state due to certain reasons and starts the timer. As time goes on, the timer continuously updates the duration of the urea injection stop. When the urea injection stop state lasts for 5 minutes (i.e. 300 seconds), the system performs step S404 to compare the value of the timer with the pre-set limit. Since the value of the timer (300 seconds) has not reached the pre-set limit (600 seconds) at this time, the system returns to step S403 to continue updating the timing value of the timer. In this way, the system continues to monitor the duration of the urea injection stop until it reaches the pre-set limit or the urea injection condition is restored. If the urea injection stop time eventually reaches or exceeds the pre-set limit, the system can take appropriate control measures, such as attempting to restore urea injection, recording fault codes, or reminding the driver to check, etc. Such a design helps to ensure that the urea injection system can resume work at the right time to reduce emission pollution and protect the normal operation of the system.

[0114] If the comparison result is that the continuous time exceeds the pre-set limit, proceed to step S500.

[0115] Specifically, when the system performs step S404 and compares the value of the timer with the pre-set limit, if the comparison result shows that the continuous time of the urea injection stop has exceeded the pre-set limit, the system proceeds to step S500 to perform a series of control and diagnostic operations.

[0116] In a specific embodiment, a urea injection system of a diesel vehicle is set with a pre-set limit of 10 minutes (i.e. 600 seconds) for the urea injection stop time. During the vehicle operation, the system enters the urea injection stop state due to certain reasons (such as engine speed being too low, exhaust temperature being too low, etc.) and starts the timer. As time goes on, the timer continuously updates the duration of the urea injection stop. If the value of the timer reaches 601 seconds (i.e. exceeds the pre-set limit of 10 minutes) during this process, the system performs step S404 to compare the value of the timer with the pre-set limit and generates a comparison result. This comparison result indicates that the urea injection stop time has exceeded the pre-set limit, and at this time the system proceeds to step S500. In step S500, the system can attempt to restore urea injection, record fault codes, remind the driver to check, or perform other necessary control and diagnostic operations to ensure emission compliance and normal operation of the system. Such a design helps to ensure that the urea injection system can take appropriate control measures in time when the urea injection stop time is too long, to reduce emission pollution and protect the normal operation of the system. At the same time, by recording and diagnosing fault codes, valuable information can be provided for subsequent maintenance and repair.

[0117] In this embodiment, the step S500 is followed by:

[0118] Real-time data is collected through various sensors installed on the vehicle, including but not limited to engine status (speed, load, etc.), ambient temperature, exhaust flow, exhaust temperature, urea solution concentration, urea pump pressure, nozzle flow, etc. In addition to real-time data, historical data is also recorded for trend analysis and pattern recognition. These data are stored in the vehicle's ECU (Engine Control Unit).

[0119] Specifically, a variety of sensors are installed on the vehicle to monitor and collect data related to engine status, environmental conditions, exhaust systems, and urea injection systems in real time. These data include but are not limited to engine speed, load, ambient temperature, exhaust flow, exhaust temperature, urea solution concentration, urea pump pressure, and nozzle flow. The purpose of real-time data collection is to provide accurate information so that the system can make timely adjustment and control decisions to ensure the accuracy and effectiveness of urea injection. In addition to real-time data, the system also records historical data. Historical data includes past sensor readings, urea injection events, fault diagnosis codes, etc. The purpose of recording historical data is to conduct trend analysis and pattern recognition, help identify potential problems, optimize urea injection strategies and improve the overall performance of the system. All collected data (real-time data and historical data) are stored in the vehicle's engine control unit. The engine control unit is a central processing unit responsible for processing and analyzing data from sensors and making control decisions based on these data. The data stored in the engine control unit can be accessed and extracted through diagnostic tools for further analysis and maintenance.

[0120] The collected raw data is cleaned to remove noise and outliers, ensuring the accuracy and reliability of the data. Key features are extracted from the preprocessed data, which should reflect the vehicle operating status and the performance of the urea injection system.

[0121] Specifically, the purpose of data cleaning is to remove noise and outliers from the collected raw data, ensuring the accuracy and reliability of the data. Noise and outliers can be caused by sensor failures, data transmission errors, or environmental factors, which can interfere with the authenticity and consistency of the data. By applying statistical methods and algorithms, such as filtering, smoothing, or threshold setting, to identify and remove noise. Use anomaly detection techniques to identify and handle outliers, such as replacing outliers with missing values, using interpolation methods to fill in missing values, or correcting according to the context. The cleaned data is more accurate and reliable, and can better reflect the true state of the vehicle and the urea injection system. The purpose of feature extraction is to extract key features from the preprocessed data, which should be able to reflect the vehicle operating state and the performance of the urea injection system. Key features refer to those variables or parameters that are closely related to the vehicle operating state and the performance of the urea injection system, and are of great significance to subsequent analysis and decision-making. By analyzing the preprocessed data, identify features related to the vehicle operating state and the performance of the urea injection system. Use statistical methods, machine learning algorithms or expert knowledge to select and extract these key features. The extracted key features can be used for subsequent analysis, modeling and decision-making, helping to better understand the vehicle operating state and the performance of the urea injection system.

[0122] In a specific embodiment, the engine control unit collects raw data of a diesel vehicle urea injection system, including engine speed, exhaust temperature, urea injection amount, etc. The following is an example of how to perform data cleaning and feature extraction: It is found that the sensor of the exhaust temperature reads abnormally high values at some time periods, which may be caused by sensor failure. Use the threshold setting method to identify these outliers and replace them with missing values. Then, use the interpolation method to fill in the missing values to ensure the continuity of the data. In the cleaned data, identify engine speed and exhaust temperature as features closely related to the vehicle operating state. It is also found that there is a certain relationship between the urea injection amount and the engine speed and exhaust temperature, so it is also taken as one of the key features. Through statistical analysis and machine learning algorithms, extract these key features and use them for subsequent analysis and modeling to evaluate the performance of the urea injection system and optimize it.

[0123] Using machine learning or deep learning models, train the model based on historical data and use real-time data to predict nozzle clogging risk or urea injection efficiency.

[0124] Specifically, historical data related to nozzle clogging risk or urea injection efficiency is collected from the vehicle operation system, including engine state (speed, load, etc.), ambient temperature, exhaust flow, exhaust temperature, urea solution concentration, urea pump pressure, nozzle flow, etc. These data are usually collected in real time by various sensors installed on the vehicle and stored in the vehicle's engine control unit. The collected raw data is cleaned to remove noise and outliers, ensuring the accuracy and reliability of the data. Data standardization or normalization is performed to enable comparison and analysis of data with different dimensions on the same scale. The data is divided into training set, validation set and test set for subsequent model training, validation and testing. According to the characteristics of the problem and the nature of the data, select the appropriate machine learning or deep learning model. For the prediction of nozzle clogging risk, a classification model (such as a convolutional neural network in deep learning) can be used to divide the clogging risk into different levels or categories. For the prediction of urea injection efficiency, a regression model (such as a fully connected neural network in deep learning) can be considered to directly predict the specific value of injection efficiency. Use the training set data to train the selected model, and adjust the model parameters through optimization algorithms to make the model accurately fit the training data. During training, monitor the loss function and performance indicators (such as accuracy, recall, precision, F1 value, etc.) of the model to evaluate the training effect of the model. Use the validation set to validate the model, and adjust the hyperparameters (such as learning rate, batch size, iteration number, etc.) of the model according to the validation results to improve the generalization ability of the model. Deploy the trained model to the vehicle operation system, and use real-time data to predict the nozzle clogging risk or urea injection efficiency. Real-time data is collected by sensors and transmitted to the engine control unit, which calls the deployed model for prediction and outputs the prediction results to the vehicle control system or driver. According to the prediction results, take appropriate control measures. For example, if the nozzle clogging risk is high, clean or replace the nozzle in advance; if the urea injection efficiency is low, adjust the urea injection strategy to improve the injection efficiency. Continuously monitor and evaluate the prediction results, and continuously optimize the model according to the feedback and data in actual application to improve the accuracy and reliability of the prediction.

[0125] In a specific embodiment, taking the prediction of nozzle clogging risk as an example:

[0126] Suppose a diesel vehicle manufacturer wants to use a machine learning model to predict nozzle clogging risk in order to improve the efficiency and reliability of the vehicle. They first collect historical data, including the occurrence of nozzle clogging events under different operating conditions, engine state, ambient temperature, and other relevant information. Then, they use a support vector machine (SVM) as a classification model and train the model using the training set data. During the training process, the model's hyperparameters and optimization algorithms are adjusted to accurately distinguish between high and low clogging risks. Finally, the trained model is deployed to the vehicle's operating system, and real-time data is used to predict the nozzle clogging risk. When the risk of clogging is high, the vehicle control system will automatically trigger a cleaning program or alert the driver to check and maintain it. Through this process, the manufacturer can achieve real-time monitoring and prediction of nozzle clogging risk, thereby improving the efficiency and reliability of the vehicle and reducing maintenance costs.

[0127] According to the model prediction results, the risk level of the current nozzle clogging is evaluated, for example, different risk thresholds can be set to divide the risk level into low, medium, and high levels.

[0128] Specifically, according to business needs or expert experience, different risk thresholds are set to divide continuous prediction results into different risk levels. For example, a low risk threshold of 0.3 and a medium risk threshold of 0.7 can be set, so that prediction results between 0 and 0.3 are considered low risk, between 0.3 and 0.7 are considered medium risk, and above 0.7 are considered high risk. According to the set risk thresholds, the continuous prediction results of the model are converted into discrete risk levels. As shown in the above example, a prediction result of 0.2 corresponds to a low risk level, a prediction result of 0.5 corresponds to a medium risk level, and a prediction result of 0.8 corresponds to a high risk level.

[0129] In a specific embodiment, the ECU collects real-time engine state, ambient temperature, and other relevant data and inputs them into the deployed model. The model outputs a prediction probability of nozzle clogging risk, which is assumed to be 0.65. According to the manufacturer's set risk thresholds (low risk threshold 0.3, medium risk threshold 0.7), the risk level of the vehicle's nozzle clogging is judged to be medium risk. Therefore, the vehicle control system can trigger the corresponding warning mechanism to remind the driver or maintenance personnel to pay attention to the nozzle state and consider cleaning or maintenance at the appropriate time to reduce the risk of clogging. Through this process, the manufacturer can evaluate the risk level of nozzle clogging in real time according to the model prediction results and take appropriate control measures to improve the efficiency and reliability of the vehicle.

[0130] A series of urea injection strategies are prepared in advance, including different injection rates, durations, intervals, and other combinations. These strategies should be customized according to vehicle models, engine characteristics, urea solution quality, and other factors.

[0131] Specifically, when developing a urea injection strategy, multiple factors need to be considered, including vehicle model, engine characteristics (such as power, speed range, emission level, etc.), urea solution quality (such as concentration, purity, temperature, etc.), and environmental conditions (such as ambient temperature, humidity, etc.). Based on the above factors, different injection rates, durations, and intervals, etc. are customized. For example, for high-power engines, higher injection rates and longer injection durations may be needed to ensure sufficient urea amount into the exhaust system to effectively reduce nitrogen oxide emissions. Different injection parameters are combined into a series of urea injection strategies. These strategies should cover various operating conditions that the vehicle may encounter to ensure optimal urea injection effect in any situation.

[0132] In a specific embodiment, assume that a car manufacturer produces two different models of diesel vehicles: Model A and Model B. These two models have different engine characteristics and emission level requirements. Model A: Engine characteristics: medium power, wide speed range, needs to meet more stringent emission level requirements. Urea injection strategy: develop a moderate injection rate, longer injection duration, and moderate injection interval. This can ensure sufficient urea reaction while avoiding waste and excessive injection. Model B: Engine characteristics: high power, narrow speed range, but relatively low emission level requirements. Urea injection strategy: develop a higher injection rate, shorter injection duration, and shorter injection interval. This can ensure that there is still enough urea amount into the exhaust system to meet emission requirements when high power output. In addition, for the two models, the injection strategy can be further adjusted according to the quality of the urea solution and the environmental conditions. For example, in cold environments, urea solution may be more prone to crystallization, so the injection strategy needs to be adjusted to avoid nozzle blockage. Through such customized urea injection strategies, different vehicle models can achieve optimal urea injection effect under different operating conditions, thereby meeting emission standards and vehicle performance requirements.

[0133] Based on the risk assessment results, select the appropriate injection strategy from the strategy library. For example, when the risk of blockage is high, a strategy of increasing injection frequency or increasing injection rate can be selected.

[0134] Specifically, first, the current risk assessment result needs to be obtained from the nozzle clogging risk prediction model. This result is usually a numerical value representing the clogging probability or risk level. According to the pre-set risk threshold or level, the current risk assessment result is matched with the injection strategy in the strategy library. For example, if the risk assessment result shows high risk, the injection strategy corresponding to the high risk level is selected. Under the matched risk level, there may be multiple specific injection strategies to choose from. At this time, the most suitable injection strategy can be further determined according to other operating parameters of the vehicle (such as engine load, exhaust temperature, etc.) and the quality of urea solution and environmental conditions.

[0135] In a specific embodiment, assume that a certain diesel vehicle is running, and its ECU has collected relevant data in real time and input it into the nozzle clogging risk prediction model. The model outputs a probability value representing the current clogging risk, which is assumed to be 0.8 (high risk). According to the pre-set risk threshold, 0.8 belongs to the high risk level. Therefore, the injection strategy corresponding to the high risk level needs to be selected from the strategy library. Under the high risk level, the strategy library may contain multiple injection strategies, such as increasing injection frequency, increasing injection rate, prolonging injection duration, etc. At this time, the ECU further considers other operating parameters of the vehicle, such as high engine load and moderate exhaust temperature. In order to quickly reduce the clogging risk, the ECU selects the strategy of "increasing injection frequency and increasing injection rate". The ECU sends the selected injection strategy parameters to the urea injection system, and the system adjusts the injection behavior according to the new parameters to increase the injection amount of urea and try to remove the clogging at the nozzle. Through this process, the vehicle can dynamically adjust the urea injection strategy according to the real-time risk assessment result to reduce the risk of nozzle clogging and maintain efficient urea injection effect. This helps to improve the emission performance and operational reliability of the vehicle.

[0136] According to the selected injection strategy, corresponding control instructions are generated. These instructions should include specific parameters such as injection rate, duration, interval, etc. The control instructions are issued to the actuators of the urea injection system (such as urea pump, nozzle, etc.) to ensure that they can inject according to the new strategy.

[0137] Specifically, according to the selected injection strategy, specific injection rate, duration, interval, and other parameters are determined. These parameters should ensure that the urea injection system can achieve the best injection effect under different operating conditions. The determined injection parameters are encoded into control instructions. These instructions usually exist in the form of digital signals and can be recognized and executed by the actuators of the urea injection system. The control instructions are transmitted to the actuators of the urea injection system, such as the urea pump, nozzle, etc., through the communication network inside the vehicle. After receiving the control instructions, the actuators adjust their working state according to the injection parameters in the instructions. For example, the urea pump adjusts its working pressure and flow rate, and the nozzle adjusts the timing and duration of its opening and closing. When the urea injection system executes a new injection strategy, it will monitor its working state in real time and send feedback signals to the ECU. This helps the ECU to monitor and adjust the injection system in real time.

[0138] In a specific embodiment, for example, the ECU of a certain diesel vehicle has selected the injection strategy of "increasing injection frequency and increasing injection rate" according to the risk assessment results. Now, the ECU needs to generate corresponding control instructions and issue these instructions to the actuators of the urea injection system. According to the selected injection strategy, the ECU determines the specific injection rate to be 5 milliliters per second, the injection duration to be 0.2 seconds each time, and the injection interval to be every 2 seconds. The ECU encodes these parameters into control instructions, and the instruction format is "injection rate: 5 milliliters / second; injection duration: 0.2 seconds; injection interval: 2 seconds". The ECU sends the control instructions to the actuators of the urea injection system, such as the urea pump and the nozzle, through the communication network inside the vehicle. After receiving the instructions, the urea pump adjusts its working pressure and flow rate to ensure that 5 milliliters of urea solution can be injected per second. After receiving the instructions, the nozzle sprays according to the frequency of every 2 seconds and the duration of 0.2 seconds each time. Through this process, the urea injection system of the diesel vehicle can accurately execute the new injection strategy according to the control instructions issued by the ECU to increase the injection amount of urea and try to reduce the risk of nozzle clogging. This helps to improve the emission performance and operating reliability of the vehicle.

[0139] Embodiment Two

[0140] Figure 2 is a structural schematic diagram of a control system for preventing crystallization and clogging of a urea nozzle in Embodiment Two of the present application, as shown in Figure 2As shown, the embodiment two provides a control system for preventing urea nozzle crystallization blockage, comprising: an acquisition module 201, a first calculation module 202, a second calculation module 203, a judgment module 204 and a spraying module 205. The acquisition module 201 is configured to acquire engine state, ambient temperature, exhaust flow and exhaust temperature. The first calculation module 202 is configured to calculate exhaust energy based on the ambient temperature, the exhaust flow and the exhaust temperature. The second calculation module 203 is configured to calculate urea rate based on the exhaust energy. The judgment module 204 is configured to judge whether the continuous time of urea stop spraying reaches a preset limit value based on the engine state and the exhaust temperature. The spraying module 205 is configured to spray urea to the catalyst according to a preset method based on the urea rate if the continuous time of urea stop spraying exceeds the preset limit value.

[0141] In the embodiment, the acquisition module 201 comprises: a first acquisition unit, a second acquisition unit, a third acquisition unit and a fourth acquisition unit. The first acquisition unit is configured to acquire engine state after the engine is powered on. The second acquisition unit is configured to acquire the ambient temperature through an ambient temperature sensor. The third acquisition unit is configured to acquire the exhaust flow through an exhaust flow sensor. The fourth acquisition unit is configured to acquire the exhaust temperature through an exhaust temperature sensor.

[0142] In the embodiment, the exhaust energy is calculated based on the ambient temperature, the exhaust flow and the exhaust temperature through a first preset formula, and the first preset formula is:

[0143] Q = ((T1-T2)*E*3.6 / 3600)

[0144] Wherein, Q represents exhaust energy, and the unit is usually kilojoule (kJ) or other energy units;

[0145] T1 represents exhaust temperature, and the unit is usually Celsius (℃);

[0146] T2 represents ambient temperature, and the unit is also Celsius (℃);

[0147] E represents exhaust flow, and the unit is usually cubic meters per hour (m 3 / h) or other flow units;

[0148] 3.6 and 3600 are unit conversion coefficients, which are used to convert the flow unit from cubic meters per hour to cubic meters per second, and convert the result to kilojoule.

[0149] In the embodiment, the urea rate is calculated based on the exhaust energy through a second preset formula, and the second preset formula is:

[0150] M = a*Q + b

[0151] wherein M represents the amount of urea that can be pyrolyzed per unit of time by exhaust energy, typically in grams (g) or other mass units;

[0152] a and b are pyrolysis constants, which are obtained through experiments or empirical data, for describing the linear relationship between exhaust energy and urea amount in the urea pyrolysis process;

[0153] Q represents exhaust energy, typically in kilojoules (kJ) or other energy units.

[0154] In the embodiment, the judging module 204 comprises a judging unit, a starting unit, an updating unit, a generating unit, a returning unit, and an entering unit. The judging unit is configured to judge whether the current is in the urea stop injection state based on the engine state and the exhaust temperature. The starting unit is configured to start a timer to record the continuous time of urea stop injection if the current is in the urea stop injection state. The updating unit is configured to continuously update the timing value of the timer during the urea stop injection. The generating unit is configured to compare the timing value with a preset limit value and generate a comparison result. The returning unit is configured to return to step S403 if the comparison result is that the continuous time does not reach the preset limit value. The entering unit is configured to enter step S500 if the comparison result is that the continuous time exceeds the preset limit.

[0155] The various variations and specific examples of the control method for preventing urea nozzle crystallization blockage provided in Embodiment One are also applicable to the control system for preventing urea nozzle crystallization blockage provided in the present embodiment. Through the foregoing detailed description of the control method for preventing urea nozzle crystallization blockage, those skilled in the art can clearly understand the implementation of the control system for preventing urea nozzle crystallization blockage in the present embodiment. Therefore, for the sake of brevity of the description, the control system for preventing urea nozzle crystallization blockage in the present embodiment will not be described in detail.

[0156] Figure 4 is a working logic flow diagram of the control method for preventing urea nozzle crystallization blockage in a specific embodiment of the present application, as shown in the present application, the working logic of the present application is as follows: Figure 4

[0157] S1, after the engine is powered on, the engine state and the exhaust flow are output in real time, the exhaust temperature is measured in real time by the exhaust temperature sensor arranged on the catalyst, and the exhaust temperature is taken as the input condition of S2 and S4.

[0158] S2, the exhaust energy Q at this time is calculated as follows: Q = ((exhaust temperature - ambient temperature) * exhaust flow * 3.6 / 3600).

[0159] ​S3, calculate the urea M that can be pyrolyzed in the unit time of the current exhaust energy Q, as follows: M=a*Q+b. a and b are pyrolysis constants based on the nozzle structure. Urea is completely pyrolyzed into ammonia, so that no crystals are formed, and urea crystals in the catalytic converter are avoided.

[0160] S4, when the engine is in the running state, the exhaust temperature is lower than the urea start spraying limit value, the urea stops spraying, the continuous urea stop spraying time is counted, and whether the limit value is reached is judged.

[0161] S5, if the continuous urea stop spraying time reaches the limit value, it means that there is a risk of forming soft crystals, and the urea nozzle crystal cleaning mode is entered.

[0162] S6, the urea is sprayed at a rate of m per unit time, and is continuously sprayed for 2s at a time, and is intermittently sprayed every 2min, so that the soft crystals formed by the spray hole are cleaned in time, and a large amount of soft crystals or hard crystals are avoided to block the urea nozzle.

[0163] Based on the above, the application adds a urea nozzle crystal cleaning mode, which is entered after the engine is not sprayed with urea for a long time to forcibly and intermittently spray urea to clean the crystals in the nozzle and avoid blockage failure; the exhaust energy is calculated by using the exhaust temperature and the exhaust flow, the spraying pressure and the spraying cone angle of the nozzle are combined, the calculation curve of the completely pyrolyzed urea amount is fitted, and the urea crystals formed in the catalytic converter due to the urea spraying are avoided; and based on a large amount of test data, the urea is sprayed according to the pyrolysis amount in the urea nozzle crystal cleaning mode, is continuously sprayed for 2s at a time, and is intermittently sprayed every 2min.

[0164] Example Three

[0165] Figure 3 is a structural schematic diagram of an electronic device in the embodiment three of the application, as Figure 3 shown, the embodiment three further provides an electronic device 300, which can include a processor 301 and a memory 302.

[0166] The memory 302 is configured to store programs; the memory 302 can include volatile memory (English: volatile memory), such as random access memory (English: random-access memory, abbreviated as RAM), such as static random access memory (English: static random-access memory, abbreviated as SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated as DDR SDRAM) and the like; the memory can also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory 302 is used to store computer programs (such as application programs, functional modules and the like for implementing the above method), computer instructions and the like. The above computer programs, computer instructions and the like can be stored in one or more memories 302. And the above computer programs, computer instructions, data and the like can be called by the processor 301.

[0167] The above computer programs, computer instructions and the like can be stored in one or more memories 302. And the above computer programs, computer instructions and the like can be called by the processor 301.

[0168] The processor 301 is configured to execute the computer programs stored in the memory 302 to implement each step in the method related to the above embodiments.

[0169] For details, please refer to the related description in the above method embodiments.

[0170] The processor 301 and the memory 302 can be an independent structure, or an integrated structure. When the processor 301 and the memory 302 are independent structures, the memory 302 and the processor 301 can be coupled and connected through the bus 303.

[0171] The electronic device of the present embodiment can execute the technical solutions in the above method, and the specific implementation process and technical principles are the same, which will not be repeated here.

[0172] Embodiment four

[0173] Embodiment four also provides a computer-readable storage medium comprising computer programs and instructions, which, when executed on a computer, cause the computer to execute the control method for preventing urea nozzle crystallization blockage according to any one of the embodiments of the present application.

[0174] The computer readable storage medium includes a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk, and various media capable of storing program codes.

[0175] The embodiment further provides a computer program product, which comprises a computer program stored in a readable storage medium, at least one processor of an electronic device can read the computer program from the readable storage medium, and the at least one processor executes the computer program to enable the electronic device to execute the scheme provided in any of the above embodiments.

[0176] It should be understood that the steps shown above can be reordered, added or deleted using various forms of flow. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical scheme of the present disclosure can be achieved, which is not limited herein.

[0177] Note that the above are only preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A control method for preventing urea nozzle crystallization and clogging, characterized in that, include: Step S100: Obtain engine status, ambient temperature, exhaust flow rate, and exhaust temperature; Step S200: Calculate the exhaust energy based on the ambient temperature, the exhaust flow rate, and the exhaust temperature; Step S300: Calculate the urea rate based on the exhaust energy; Step S400: Based on the engine status and the exhaust temperature, determine whether the continuous time of urea injection stoppage has reached a preset limit. Step S500: If the continuous time of urea spraying stoppage exceeds a preset limit, urea is sprayed into the catalyst according to a preset method based on the urea rate. The urea rate refers to the amount of urea that can be pyrolyzed per unit time under the current exhaust energy conditions. If the continuous time that urea spraying is stopped reaches the preset limit, it indicates that the urea nozzle may be blocked by crystals due to prolonged lack of urea spraying, and corresponding measures need to be taken to prevent or remove this blockage.

2. The control method for preventing urea nozzle crystallization and clogging as described in claim 1, characterized in that, Step S100 includes: Step S101: After the engine is powered on, obtain the engine status; Step S102: Obtain the ambient temperature using an ambient temperature sensor; Step S103: Obtain the exhaust flow rate using an exhaust flow sensor; Step S104: Obtain the exhaust temperature using an exhaust temperature sensor.

3. The control method for preventing urea nozzle crystallization and clogging as described in claim 1, characterized in that, The exhaust energy is calculated based on the ambient temperature, the exhaust flow rate, and the exhaust temperature using a first preset formula, which is: Q = ((T1-T2)*E*3.6 / 3600) Where Q is the exhaust energy, T1 is the exhaust temperature, T2 is the ambient temperature, and E is the exhaust flow rate.

4. The control method for preventing urea nozzle crystallization and clogging as described in claim 1, characterized in that, Based on the exhaust energy, the urea rate is calculated using a second preset formula, which is: M = a * Q + b Where M is the urea that can be pyrolyzed per unit time by exhaust energy, a and b are both pyrolysis constants, and Q is the exhaust energy.

5. The control method for preventing urea nozzle crystallization and clogging as described in claim 1, characterized in that, Step S400 includes: Step S401: Based on the engine status and the exhaust temperature, determine whether the current state is urea injection off. Step S402: If the current state is urea injection stop, start the timer to record the continuous time of urea injection stop. Step S403: During the period when urea spraying is stopped, the timing value of the timer is continuously updated; Step S404: Compare the timing value with a preset limit value to generate a comparison result; Step S405: If the comparison result is that the continuous time does not reach the preset limit, then return to step S403; Step S406: If the comparison result is that the continuous time exceeds a preset limit, then proceed to step S500.

6. A control system for preventing urea nozzle crystallization and clogging, characterized in that, include: The acquisition module is used to acquire engine status, ambient temperature, exhaust flow rate, and exhaust temperature. The first calculation module is used to calculate the exhaust energy based on the ambient temperature, the exhaust flow rate, and the exhaust temperature. The second calculation module is used to calculate the urea rate based on the exhaust energy; The judgment module is used to determine whether the continuous time of urea injection stoppage has reached a preset limit based on the engine status and the exhaust temperature. as well as The injection module is used to inject urea into the catalyst according to a preset method based on the urea rate if the continuous time of urea injection stoppage exceeds a preset limit. The urea rate refers to the amount of urea that can be pyrolyzed per unit time under the current exhaust energy conditions. If the continuous time that urea spraying is stopped reaches the preset limit, it indicates that the urea nozzle may be blocked by crystals due to prolonged lack of urea spraying, and corresponding measures need to be taken to prevent or remove this blockage.

7. The control system for preventing urea nozzle crystallization and clogging as described in claim 6, characterized in that, The acquisition module includes: The first acquisition unit is used to acquire the engine status after the engine is powered on; The second acquisition unit is used to acquire the ambient temperature through an ambient temperature sensor; The third acquisition unit is used to acquire the exhaust flow rate via an exhaust flow sensor; and The fourth acquisition unit is used to acquire the exhaust temperature through an exhaust temperature sensor.

8. The control system for preventing urea nozzle crystallization and clogging as described in claim 6, characterized in that, The exhaust energy is calculated based on the ambient temperature, the exhaust flow rate, and the exhaust temperature using a first preset formula, which is: Q = ((T1-T2)*E*3.6 / 3600) Where Q is the exhaust energy, T1 is the exhaust temperature, T2 is the ambient temperature, and E is the exhaust flow rate.

9. An electronic device, characterized in that, include: At least one processor; as well as A memory that is communicatively connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the control method for preventing urea nozzle crystallization blockage as described in any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, It includes computer programs and instructions that, when the computer program or the instructions are run on a computer, cause the computer to perform the control method for preventing urea nozzle crystallization blockage as described in any one of claims 1-5.

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