Urea nozzle dredging method, equipment and storage medium

Abstract

The present application provides a urea nozzle unclogging method, device, and storage medium, relating to the field of engine aftertreatment technology. The method comprises: upon determining that a urea nozzle is clogged, unclogging the urea nozzle according to a urea system injection strategy, and determining whether the urea system injection strategy has unblocked the urea nozzle; if it is determined that the urea system injection strategy has not unblocked the urea nozzle, determining the crystallization state of the urea nozzle based on the pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state indicating that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state indicating that the blocking crystals are one or more of ammeline and ammelide; determining a target fuel injection amount based on the crystallization state, and controlling the HCI system to unblock the urea nozzle according to the target fuel injection amount. The method of the present application can resolve the problem of urea nozzle clogs.

Description

Technical Field

[0001] The present application relates to the technical field of engine aftertreatment, and in particular to a urea nozzle dredging method, equipment, and storage medium. Background Art

[0002] The typical exhaust after-treatment principle is as follows: a urea nozzle is placed on the exhaust pipe upstream of the SCR carrier, and urea solution is sprayed into the exhaust pipe from the nozzle. The spray droplets mix with the exhaust gas and undergo evaporation, thermal decomposition and other processes. The urea decomposes into NH3 and HCNO. Under the action of the catalyst, HCNO is further hydrolyzed into NH3. NOx in the exhaust undergoes a selective catalytic reduction reaction with NH3 under the action of the catalyst, ultimately generating pollution-free N2 and H2O.

[0003] Urea injection systems typically use a 32.5% urea solution as a reducing agent. However, due to the special properties of urea solution, a series of complex chemical reactions occur during the production of ammonia. These reactions produce a variety of intermediate products, which can cause urea nozzle blockage.

[0004] In view of the above-mentioned defects, there is an urgent need for a urea nozzle unclogging method, equipment and storage medium that can solve the problem of urea nozzle clogging. Summary of the Invention

[0005] The present application provides a urea nozzle dredging method, device and storage medium to solve the problem of urea nozzle clogging.

[0006] In a first aspect, the present application provides a method for unclogging a urea nozzle, comprising:

[0007] When it is determined that the urea nozzle is clogged, unblocking the urea nozzle according to a urea system injection strategy, and determining whether the urea system injection strategy unblocks the urea nozzle;

[0008] If it is determined that the urea system injection strategy has not unblocked the urea nozzle, determining a crystallization state of the urea nozzle based on the pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state being used to indicate that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state being used to indicate that the blocking crystals are one or more of ammeline and ammelide;

[0009] A target fuel injection amount is determined according to the crystallization state, and an HCI system is controlled to unclog the urea nozzle according to the target fuel injection amount.

[0010] In one possible design, determining the crystallization state of the urea nozzle according to the pre-SCR temperature includes:

[0011] Obtaining an average value of the temperature before the SCR within a preset sampling time period as a first average temperature;

[0012] If the first average temperature is not greater than a first preset temperature, determining that the crystallization state of the urea nozzle is the first state;

[0013] If the first average temperature is greater than a first preset temperature and not greater than a sixth preset temperature, determining that the crystallization state of the urea nozzle is the second state;

[0014] If the first average temperature is greater than a sixth preset temperature, determining a crystallization state of the urea nozzle according to the pre-SCR temperature within a third preset time period;

[0015] Wherein, the first preset temperature is lower than the sixth preset temperature.

[0016] In a possible design, determining the crystallization state of the urea nozzle according to the pre-SCR temperature within a third preset time period includes:

[0017] Obtaining a cumulative time during which the pre-SCR temperature is greater than a fifth preset temperature within a third preset time period as a third cumulative time; wherein the sixth preset temperature is less than the fifth preset temperature;

[0018] If the third accumulated time is not greater than a fourth preset time and the urea nozzle is clogged, determining that the crystallization state of the urea nozzle is the second state;

[0019] If the third accumulated time is not greater than the fourth preset time and the urea nozzle is not blocked, it is determined that the urea nozzle has been unblocked;

[0020] If the third accumulated time is greater than the fourth preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to a driver console.

[0021] In one possible design, if the crystallization state is determined to be the first state, determining a target fuel injection amount according to the crystallization state, and controlling the HCI system to unclog the urea nozzle according to the target fuel injection amount include:

[0022] Determining a first target fuel injection amount based on a second preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel based on the first target fuel injection amount; the second preset temperature being a target temperature of the DPF;

[0023] Obtaining a first accumulated time during which the pre-SCR temperature is not less than a third preset temperature;

[0024] Whether the urea nozzle is unblocked is determined according to the first accumulated time.

[0025] In a possible design, determining whether the urea nozzle is unblocked according to the first accumulated time includes:

[0026] If the first accumulated time is not less than the first preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and the crystallization state is determined to be the second state;

[0027] If the first accumulated time is less than the first preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked, and the fuel injection is stopped.

[0028] In one possible design, if the crystallization state is determined to be the second state, determining a target fuel injection amount according to the crystallization state, and controlling the HCI system to unclog the urea nozzle according to the target fuel injection amount include:

[0029] determining a second target fuel injection amount according to a fourth preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel according to the second target fuel injection amount, wherein the fourth preset temperature is a target temperature of the DPF;

[0030] acquiring a second accumulated time during which the pre-SCR temperature is not less than a fifth preset temperature;

[0031] Whether the urea nozzle is unblocked is determined according to the second accumulated time.

[0032] In one possible design, determining whether the urea nozzle is unblocked according to the second accumulated time includes:

[0033] If the second accumulated time is not less than the second preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to the driver console;

[0034] If the second accumulated time is less than the second preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked, and the fuel injection is stopped.

[0035] In one possible design, the urea nozzle is unblocked according to the urea system injection strategy, including:

[0036] Controlling the urea system to perform one or more injections according to a preset duty cycle, a preset injection duration, and a preset rest time;

[0037] The determining whether the urea system injection strategy unclogs the urea nozzle includes:

[0038] If the number of injections of the urea system is not greater than a preset number and it is determined that the urea nozzle is not blocked, it is determined that the urea nozzle is unblocked;

[0039] If the number of injections of the urea system is greater than a preset number and it is determined that the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked.

[0040] In a second aspect, the present application provides a urea nozzle dredging device, comprising:

[0041] The first module is configured to, when determining that the urea nozzle is clogged, unclog the urea nozzle according to a urea system injection strategy, and determine whether the urea system injection strategy unclogs the urea nozzle;

[0042] a second module configured to, if it is determined that the urea system injection strategy has not unblocked the urea nozzle, determine a crystallization state of the urea nozzle based on a pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state being used to indicate that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state being used to indicate that the blocking crystals are one or more of ammeline and ammelide;

[0043] The third module is configured to determine a target fuel injection amount according to the crystallization state, and control the HCI system to unclog the urea nozzle according to the target fuel injection amount.

[0044] In a third aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0045] The memory stores computer-executable instructions;

[0046] The processor executes the computer-executable instructions stored in the memory to implement a urea nozzle unclogging method.

[0047] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement a urea nozzle unclogging method.

[0048] The urea nozzle unclogging method, device, and storage medium provided herein determine the crystallization state of the urea nozzle based on the pre-SCR temperature when the urea system injection strategy fails to unblock the nozzle. Different target fuel injection amounts are determined for different crystallization states, and the HCI system is controlled to unblock the urea nozzle based on the target fuel injection amount. This achieves the following technical effects:

[0049] This application divides the crystallization state of the urea nozzle into a first state and a second state according to the pre-SCR temperature. In different states, the HCI injection system injects different fuel amounts to increase the temperature of the pipe where the urea nozzle is located, which can more effectively unclog the urea nozzle;

[0050] According to different crystal types, the fuel injection amount of the HCI injection system can be controlled more accurately, which can reduce fuel consumption while unclogging the urea nozzle to ensure fuel economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0052] Figure 1 This is a diagram of an application scenario of the urea nozzle dredging method provided in an embodiment of the present application;

[0053] Figure 2 Schematic diagram of the process of urea nozzle unclogging method provided in the embodiment of the present application Figure 1 ;

[0054] Figure 3 Schematic diagram of the process of urea nozzle unclogging method provided in the embodiment of the present application Figure 2 ;

[0055] Figure 4 This is a schematic diagram of the process in S303 in the embodiment of this application Figure 3 ;

[0056] Figure 5 A schematic diagram of the structure of a urea nozzle dredging device provided in an embodiment of the present application;

[0057] Figure 6 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims, rather than all embodiments. Based on the embodiments of 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.

[0059] It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0060] It should be noted that the terms "first," "second," "third," "fourth," and so on (if any) in the description and claims of the present invention and the drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present invention described herein can, for example, be implemented in an order other than those illustrated or described herein.

[0061] It should be noted that the “at…” in the embodiments of the present application can be the instant when a certain situation occurs, or it can be a period of time after the occurrence of a certain situation. The embodiments of the present application do not make specific limitations on this.

[0062] First, the relevant concepts or terms involved in this application are explained:

[0063] DOC (Diesel Oxidation Catalyst): An oxidation catalytic converter is a device installed in the engine exhaust line that converts carbon monoxide (CO) and hydrocarbons (HC) in the engine exhaust into harmless water (H2O) and carbon dioxide (CO2) through oxidation reaction.

[0064] DPF (Diesel Particulate Filter): Diesel particulate filter, mainly used to capture and process carbon particles such as particulate matter, hydrocarbons, nitrogen oxides, etc.

[0065] SCR (Selective Catalytic Reduction): Selective catalytic reduction system, an exhaust gas treatment strategy for emissions. The technical principle is to use a reducing agent under the action of a catalyst to selectively reduce nitrogen oxides to nitrogen and water in an oxygen-rich environment.

[0066] ASC (Ammonia Slip Catalys): An ammonia slip catalyst installed at the rear end of the SCR. It reduces ammonia (NH3) leaked from the exhaust gas at the rear end of the SCR through catalytic oxidation.

[0067] HCI injection system (Hydro Carbon Injection): A fuel injection module used to control the DPF regeneration temperature. It consists of two components: the MU (Metering Unit) and the IU (Injection Unit).

[0068] Urea injection system: Urea is sprayed from the nozzle. After injection, the urea will react chemically with nitrogen oxides (NOx) in the exhaust gas and convert into nitrogen and water, thereby achieving the purpose of reducing nitrogen oxide emissions.

[0069] Existing aftertreatment systems typically have a urea nozzle fault diagnosis strategy. This strategy uses pressure sensors or auxiliary methods such as conversion efficiency to determine if a urea nozzle is clogged. Intermittent, high-flow injection is then typically used to attempt to dislodge or melt the clogged urea nozzle. While this approach is effective for blockages caused by urea crystals, urea crystals, at high temperatures, can form biuret, cyanuric acid (CYA), CYA homologues, and even more complex polymers, forming crystals. These methods are largely ineffective for such crystal blockages.

[0070] Figure 1 This is a schematic diagram of an application scenario of the urea nozzle blocking method provided in an embodiment of the present application. The method is used in an after-treatment system of an engine, which includes a DOC101, a DPF102, an SCR103 and an ASC104 connected to an engine exhaust port. The system also includes an HCI system 105 and a urea injection system 106. The fuel nozzle of the HCI system 105 is arranged in a pipe upstream of the DOC101. A first temperature sensor is also arranged in the pipe upstream of the DOC101 for measuring the temperature upstream of the DOC101 (i.e., the pre-DOC temperature); correspondingly, a second temperature sensor is also arranged in the pipe downstream of the DOC101 for measuring the temperature downstream of the DOC101 (i.e., the post-DOC temperature); the urea nozzle of the urea injection system 106 is arranged in a pipe upstream of the SCR103; a third temperature sensor is also arranged in the pipe upstream of the SCR103 for measuring the temperature upstream of the SCR103 (i.e., the pre-SCR temperature).

[0071] The method of the present application determines the crystallization state of the urea nozzle based on the pre-SCR temperature when the urea system injection strategy fails to unclog the nozzle. Different target temperatures are set for different crystallization states, and the HCI system is controlled to unclog the nozzle according to the target temperatures. The HCI injection system can inject different amounts of fuel to increase the temperature of the pipe where the urea nozzle is located, effectively unclogging the urea nozzle.

[0072] The urea nozzle unclogging method provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0073] Figure 2 Schematic diagram of the process of urea nozzle unclogging method provided in the embodiment of the present application Figure 1 .like Figure 2 As shown, the method includes:

[0074] S201: when it is determined that the urea nozzle is clogged, unblocking the urea nozzle according to the urea system injection strategy, and determining whether the urea system injection strategy unblocks the urea nozzle;

[0075] Specifically, the urea system injection strategy is to control the urea nozzle to perform one or more injections according to a preset duty cycle, a preset injection duration, and a preset number of injections;

[0076] If the number of times the urea system is injected is greater than the preset number and it is determined that the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and the process continues with S202 .

[0077] S202: If it is determined that the urea system injection strategy has not unblocked the urea nozzle, determine a crystallization state of the urea nozzle based on the pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state indicating that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state indicating that the blocking crystals are one or more of ammeline and ammelide;

[0078] Specifically, an average value of the temperature before the SCR within a preset sampling period is obtained as a first average temperature; a crystallization state of the blocked nozzle is determined based on the first average temperature;

[0079] As its principle, according to the chemical reaction mechanism of urea thermal decomposition, at room temperature ~ 463K, urea undergoes urea evaporation and decomposition reaction; the products mainly include biuret, and a small amount of CYA (cyanuric acid) and ammelide (cyanuric acid monoamide); at 463 ~ 523K, urea continues to decompose, and biuret also begins to decompose, and the mass of components such as CYA (cyanuric acid), ammelide (cyanuric acid monoamide), and ammeline (cyanuric acid diamide) gradually increases; when the temperature reaches 523 ~ 633K, urea and Biuret has completely decomposed, and components such as CYA (cyanuric acid), ammelide (ammeline), and ammeline (ammeline diamide) begin to evaporate and decompose. When the temperature is above 633K, decomposition is still the main reaction. CYA (cyanuric acid) can be completely decomposed between 648 and 653K. Ammelide (ammeline diamide) begins to melt and decompose at 683K, and decomposition is completed when the temperature reaches above 873K. Ammeline (ammeline diamide) begins to melt and decompose at 708K, and decomposition is complete at 973K.

[0080] According to the above reaction mechanism, this embodiment divides the crystallization state into a first state and a second state according to the first average temperature, so that the urea nozzle can be unblocked according to different states in the next step.

[0081] S203: Determine a target fuel injection amount according to the crystallization state, and control the HCI system to unclog the urea nozzle according to the target fuel injection amount.

[0082] Specifically, different target fuel injection amounts are determined for different crystallization states, and the HCI system is controlled to unclog the urea nozzle according to the target fuel injection amount.

[0083] The method provided in this embodiment determines the crystallization state of the urea nozzle based on the pre-SCR temperature when the urea system injection strategy is unable to unclog the urea nozzle. Different target fuel injection amounts are determined for different crystallization states, and the HCI system is controlled to unclog the urea nozzle according to the target fuel injection amount. The following technical effects are achieved:

[0084] This embodiment divides the crystallization state of the urea nozzle into a first state and a second state according to the pre-SCR temperature. In different states, the HCI injection system injects fuel according to different injection amounts to increase the temperature of the pipe where the urea nozzle is located, which can more effectively unclog the urea nozzle.

[0085] According to different crystal types, the fuel injection amount of the HCI injection system can be controlled more accurately, which can reduce fuel consumption while unclogging the urea nozzle to ensure fuel economy.

[0086] Figure 3 Schematic diagram of the urea nozzle unclogging method provided in the embodiment of this application Figure 2 .like Figure 3 As shown, the method includes:

[0087] S301: When it is determined that the urea nozzle is clogged, unblocking the urea nozzle according to the urea system injection strategy;

[0088] Specifically, there are many methods for determining whether the urea nozzle is clogged, all of which can be used as methods for determining whether the urea nozzle is clogged in this embodiment and will not be described in detail later. For example, the urea nozzle clogged can be determined based on the urea pump speed or the urea pressure value.

[0089] For example, if it is determined that the urea pump speed is lower than a preset speed, it is determined that the urea nozzle is clogged;

[0090] For another example, a urea pressure value of a urea injection system is obtained. When it is determined that the urea pressure value is greater than a preset pressure and lasts for a time greater than a preset time value, it is determined that the urea nozzle is clogged.

[0091] Furthermore, when it is determined in this step that the urea nozzle is clogged, a message indicating that the urea nozzle is being unblocked is sent to the driver console;

[0092] Specifically, the urea system injection strategy is: controlling the urea system to perform one or more injections according to a preset duty cycle, a preset injection duration, and a preset rest time;

[0093] In this embodiment, the preset duty cycle is 100%, the preset injection duration is 20 seconds, and the preset rest interval is 20 seconds.

[0094] S302: Determine whether the urea system injection strategy unclogs the urea nozzle; if it is determined that the urea nozzle is not unclogged, execute S303.

[0095] Specifically, if the number of times the urea system is injected is not greater than a preset number and it is determined that the urea nozzle is not blocked, it is determined that the urea nozzle is unblocked;

[0096] If the number of times the urea system is injected is greater than the preset number and it is determined that the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked.

[0097] Specifically, in this embodiment, the preset number of times is 3 times.

[0098] Correspondingly, in this step and subsequent steps, if it is determined that the urea nozzle has been unblocked, a message indicating that the urea nozzle is normal is sent to the driver console, which will not be repeated in subsequent steps.

[0099] S303. Obtain the average pre-SCR temperature within a preset sampling time period as a first average temperature; determine the crystallization state of the clogged nozzle based on the first average temperature. If the crystallization state is the first state, perform S304; if the crystallization state is the second state, perform S306.

[0100] Specifically, the preset sampling time period is 30 seconds, and the pre-SCR temperature 30 seconds before the current time is obtained and a mean filtering operation is performed to obtain a first average temperature.

[0101] Specifically, the crystallization state includes a first state and a second state. The first state is used to indicate that the blocking crystals are one or more of biuret, urea and cyanuric acid, and the second state is used to indicate that the blocking crystals are one or more of ammeline and ammeline. For different states, the method of this embodiment adopts different methods to unclog the urea nozzle.

[0102] As a preferred embodiment, Figure 4 This is a schematic diagram of the process in S303 in the embodiment of this application Figure 3 ,like Figure 4 , determining the crystallization state of the urea nozzle according to the first average temperature, including:

[0103] S3031: If the first average temperature is not greater than the first preset temperature, determine that the crystallization state of the blocked nozzle is the first state;

[0104] S3032: If the first average temperature is greater than the first preset temperature and not greater than the sixth preset temperature, determining that the crystallization state of the urea nozzle is the second state;

[0105] S3033: If the first average temperature is greater than the sixth preset temperature, obtain the cumulative time during which the pre-SCR temperature is greater than the fifth preset temperature within the third preset time period as a third cumulative time; and make a determination based on the third cumulative time and the urea nozzle blockage condition.

[0106] Specifically, there is no clear order relationship between S3031 to S3033.

[0107] Specifically, the third accumulated time is used to determine the duration of the temperature before the SCR being at a high temperature (greater than the fifth preset temperature); the judgment steps are S3034 to S3036:

[0108] S3034: If the third accumulated time is not greater than the fourth preset time and it is determined that the urea nozzle is not blocked, it is determined that the blockage has been cleared.

[0109] Specifically, if the third accumulated time is not greater than the fourth preset time, and within this time period, it is determined that the urea nozzle is not clogged, then it is determined that the blockage has been cleared, and a message indicating that the urea nozzle is normal is sent to the driver console.

[0110] S3035: If the third accumulated time is not greater than the fourth preset time and the urea nozzle is determined to be clogged, determine that the crystallization state of the urea nozzle is the second state;

[0111] Specifically, if the third accumulated time is not greater than the fourth preset time, but the urea nozzle is still clogged, we determine that the high temperature duration is not long enough to eliminate the crystallization blockage caused by ammeline; and determine that the crystallization state of the urea nozzle is the second state;

[0112] S3036: If the third accumulated time is greater than the fourth preset time and it is determined that the urea nozzle is still clogged; it is determined that the urea nozzle is not unblocked, sending a message indicating a urea nozzle failure to the driver console;

[0113] Specifically, if the third accumulated time is greater than the fourth preset time but the urea nozzle is still clogged, it is determined that the blockage does not belong to the crystallization situation indicated by the first state or the second state, and it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to the driver console.

[0114] Specifically, the first preset temperature is less than the sixth preset temperature and less than the fifth preset temperature;

[0115] Furthermore, in this embodiment, the first preset temperature is 220° C., the sixth preset temperature is 400° C., the fifth preset temperature is 680° C., the third preset time period is 10 minutes, and the fourth preset time period is 5 minutes.

[0116] S304: If the crystallization state of the urea nozzle is determined to be the first state, a first target fuel injection amount is determined based on a second preset temperature, a pre-DOC temperature, and a post-DOC temperature, and the HCI injection system is controlled to inject fuel according to the first target fuel injection amount; the second preset temperature is a target temperature of the DPF;

[0117] Specifically, the first target fuel injection amount is the target fuel injection amount required by the DPF device calculated by the DPF device based on the DPF target temperature, the pre-DOC temperature and the post-DOC temperature. The HCI injection system is controlled to perform fuel injection according to the first target fuel injection amount. In this embodiment, the second preset temperature is 400°C.

[0118] There are various methods for calculating the fuel injection amount of an HCI system in the prior art, including but not limited to open-loop methods and closed-loop methods;

[0119] In one possible embodiment, the DPF inlet target temperature is determined, and the target temperature inside the DOC and the hydrocarbon (fuel) open-loop oil volume required for DOC temperature increase are calculated based on the DPF inlet temperature and the DOC physical model; the actual temperature inside the DOC is calculated based on the DOC physical model; the feedback hydrocarbon volume is calculated based on the difference between the actual temperature and the target temperature; and the hydrocarbon demand is obtained by calculating the sum of the open-loop oil volume and the feedback oil volume.

[0120] In another possible embodiment, the required fuel injection amount is obtained according to the following formula:

[0121]

[0122] Among them, q is the required injection amount, M e is the exhaust mass flow rate, C p is the exhaust gas specific heat capacity, T docin is the temperature before DOC, H is the calorific value of the regenerated fuel, n is the combustion efficiency of the regenerated fuel in the oxidation catalyst, T ctr is the regeneration control temperature output by the internal model control module, where T ctr Calculated using the following formula:

[0123] T ctr =G IMC (s)·(T targ -ΔT)

[0124] Where T targ is the target temperature of DPF, ΔT is the difference between the estimated value and the actual value of the temperature after DOC, according to G IMC (s) is the transfer function of the internal model control module.

[0125]

[0126]

[0127]

[0128] Among them G m- (S) is the transfer function with minimum phase characteristics in the oxidation catalyst model that is stable and does not contain prediction terms, f(s) is the filter in the internal model control module; T is the filter parameter.

[0129] S305 , obtaining a first accumulated time during which the temperature before the SCR is not less than a third preset temperature, and determining whether the urea nozzle is unblocked based on the first accumulated time; if not, determining that the crystallization state is the second state, and executing S306 .

[0130] Specifically, starting from when the pre-SCR temperature is equal to the third preset temperature, obtaining a duration during which the pre-SCR temperature is not less than the third preset temperature as the first accumulated time;

[0131] determining whether the urea nozzle is clogged during a period when the first accumulated time is not less than a first preset time;

[0132] If the first accumulated time is not less than the first preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, fuel injection is stopped, and the crystallization state of the urea nozzle is determined to be the second state;

[0133] If the first accumulated time is less than the first preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked and the fuel injection is stopped.

[0134] Specifically, the third preset temperature is greater than the first preset temperature; in this embodiment, the third preset temperature is 380° C., and the first preset time is 10 minutes.

[0135] Specifically, it is considered that when the pre-SCR temperature is above the third preset temperature, the PDF has reached the target temperature (the second preset temperature). At the target temperature, the downstream discharge temperature of the PDF can decompose the crystallization problem of biuret, urea, and cyanuric acid. Therefore, the first accumulated time is the time for decomposing the crystallization of the urea nozzle. When the first accumulated time lasts until the first preset time, the crystallization problem of biuret, urea, and cyanuric acid should be resolved. If the urea nozzle is still clogged, it is determined that the crystallization state is the second state, and S306 is executed.

[0136] In actual operation, even when the pre-SCR temperature is above the third preset temperature and lasts for the first preset time, cyanuric acid may not be completely decomposed and a small amount may remain. S306-S307 executed after determining that the crystallization state is the second state can continue to decompose the small amount of residue.

[0137] In another preferred embodiment, S305 is replaced by: after the temperature before the SCR reaches a third preset temperature, controlling the HCI injection system to perform fuel injection according to the first target fuel injection amount for a first preset time, determining whether the urea nozzle is clogged; if so, executing S306; otherwise, determining that the urea nozzle is unblocked.

[0138] S306: If the crystallization state of the urea nozzle is determined to be the second state, determining a second target fuel injection amount based on a fourth preset temperature, the pre-DOC temperature, and the post-DOC temperature; and controlling the HCI injection system to inject fuel based on the second target fuel injection amount, with the fourth preset temperature being a target temperature of the DPF.

[0139] Specifically, the method for determining the second target fuel injection amount according to the fourth preset temperature, the pre-DOC temperature, and the post-DOC temperature is the same as that in S304 and will not be described in detail here.

[0140] Specifically, in this embodiment, the fourth target temperature is 700°C.

[0141] S307. Obtain a second accumulated time during which the pre-SCR temperature is not less than a fifth preset temperature; determine whether the urea nozzle is unblocked based on the second accumulated time; and send a message indicating a urea nozzle failure to the driver console when it is determined that the urea nozzle is not unblocked.

[0142] Specifically, starting from when the pre-SCR temperature is equal to the fifth preset temperature, obtaining a duration during which the pre-SCR temperature is not less than the fifth preset temperature as the second accumulated time;

[0143] determining whether the urea nozzle is clogged during a period when the second accumulated time is not less than a second preset time;

[0144] If the second accumulated time is not less than the second preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, fuel injection is stopped, and a message indicating a urea nozzle failure is sent to the driver console.

[0145] If the second accumulated time is less than the second preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked and the fuel injection is stopped.

[0146] Specifically, in this embodiment, the second preset time is 5 minutes.

[0147] Specifically, here we believe that when the temperature before SCR is above the fifth preset temperature, PDF has reached the fourth preset temperature. At the second temperature, the exhaust temperature downstream of PDF can decompose the crystallization problem of ammeline and ammeline. Therefore, the second cumulative time is the time for decomposing the crystallization of the urea nozzle. When the second cumulative time lasts to the second preset time, the crystallization problem of ammeline and ammeline should be solved. If the urea nozzle is still clogged, it is determined that other higher molecular polymers or impurities may exist in the crystals of the treated urea nozzle, which cannot be completely eliminated by high temperature. It is necessary to send a message to the driver console to indicate a urea nozzle failure.

[0148] In another preferred embodiment, S307 is replaced by: after the temperature before the SCR reaches a fifth preset temperature, controlling the HCI injection system to perform fuel injection according to the second target fuel injection amount for a second preset time, determining whether the urea nozzle is clogged; if so, sending a message indicating a urea nozzle failure to the driver console; otherwise, determining that the urea nozzle is unblocked.

[0149] Using the method provided in this embodiment, when the urea system injection strategy is unable to unclog the urea nozzle, the crystallization state of the urea nozzle is determined based on the pre-SCR temperature. Different target fuel injection amounts are determined for different crystallization states, and the HCI system is controlled to unclog the urea nozzle according to the target fuel injection amount. The following technical effects are achieved:

[0150] This application first uses a urea system injection strategy to unclog the urea nozzle. If the urea nozzle is still clogged after multiple urea injections, it is determined that the clogged crystals are crystals generated by the subsequent thermal decomposition of urea. The crystallization state of the urea nozzle is divided into a first state and a second state according to the pre-SCR temperature.

[0151] Under different crystallization states, the HCI injection system sprays according to different injection amounts to increase the temperature of the pipe where the urea nozzle is located to unclog the urea nozzle. If it is determined that dredging is not possible, further judgment will be made until the urea nozzle is dredged, or if it is determined that the urea nozzle is not blocked by urea thermal decomposition products, a urea nozzle fault will be reported. The urea nozzle can be dredged effectively.

[0152] According to different crystal types, the fuel injection amount of the HCI injection system can be controlled more accurately, which can reduce fuel consumption while unclogging the urea nozzle to ensure fuel economy.

[0153] In an embodiment of the present invention, the electronic device or main control device can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0154] Figure 5 This is a schematic diagram of the structure of the urea nozzle dredging device provided in the embodiment of the present application. Figure 5 As shown, the device 50 includes:

[0155] The first module 501 is configured to, when determining that the urea nozzle is clogged, unclog the urea nozzle according to the urea system injection strategy, and determine whether the urea system injection strategy unclogs the urea nozzle;

[0156] The second module 502 is configured to determine a crystallization state of the urea nozzle based on the pre-SCR temperature if it is determined that the urea system injection strategy has not unblocked the urea nozzle. The crystallization state includes a first state and a second state. The first state indicates that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state indicates that the blocking crystals are one or more of ammeline and ammelide.

[0157] The third module 503 is configured to determine a target fuel injection amount according to the crystallization state, and control the HCI system to unclog the urea nozzle according to the target fuel injection amount.

[0158] Furthermore, the second module 502 is specifically configured to:

[0159] Obtaining an average value of the temperature before the SCR within a preset sampling time period as a first average temperature;

[0160] If the first average temperature is not greater than the first preset temperature, determining that the crystallization state of the urea nozzle is the first state;

[0161] If the first average temperature is greater than the first preset temperature and not greater than the sixth preset temperature, determining that the crystallization state of the urea nozzle is the second state;

[0162] If the first average temperature is greater than a sixth preset temperature, determining a crystallization state of the urea nozzle according to the pre-SCR temperature within the third preset time period;

[0163] The first preset temperature is lower than the sixth preset temperature.

[0164] Furthermore, the second module 502 is further configured to:

[0165] Obtaining the accumulated time during which the pre-SCR temperature is greater than the fifth preset temperature within the third preset time period as the third accumulated time; the sixth preset temperature is less than the fifth preset temperature;

[0166] If the third accumulated time is not greater than the fourth preset time and the urea nozzle is clogged, determining that the crystallization state of the urea nozzle is the second state;

[0167] If the third accumulated time is not greater than the fourth preset time and the urea nozzle is not clogged, it is determined that the urea nozzle has been unblocked;

[0168] If the third accumulated time is greater than the fourth preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to the driver console.

[0169] Furthermore, the third module 503 is specifically configured to:

[0170] If the crystallization state is determined to be the first state, determining a first target fuel injection amount according to a second preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel according to the first target fuel injection amount; the second preset temperature being a target temperature of the DPF;

[0171] Obtaining a first accumulated time during which the temperature before the SCR is not less than a third preset temperature;

[0172] Whether the urea nozzle is unblocked is determined according to the first accumulated time.

[0173] Furthermore, the third module 503 is further configured to:

[0174] If the first accumulated time is not less than the first preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and the crystallization state is determined to be the second state;

[0175] If the first accumulated time is less than the first preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked and the fuel injection is stopped.

[0176] Furthermore, the third module 503 is further configured to:

[0177] If the crystallization state is determined to be the second state, determining a second target fuel injection amount according to a fourth preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel according to the second target fuel injection amount, with the fourth preset temperature being a target temperature of the DPF;

[0178] Obtaining a second accumulated time during which the temperature before the SCR is not less than a fifth preset temperature;

[0179] Whether the urea nozzle is unblocked is determined according to the second accumulated time.

[0180] Furthermore, the third module 503 is further configured to:

[0181] If the second accumulated time is not less than the second preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to the driver console;

[0182] If the second accumulated time is less than the second preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked and fuel injection is stopped.

[0183] Furthermore, the first module 501 is specifically configured to:

[0184] Control the urea system to perform one or more injections according to a preset duty cycle, preset injection duration, and preset rest time;

[0185] Furthermore, the first module 501 is further configured to:

[0186] If the number of urea system injections is not greater than the preset number and the urea nozzle is determined to be unblocked, it is determined that the urea nozzle has been unblocked;

[0187] If the number of times the urea system is injected is greater than the preset number and it is determined that the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked.

[0188] The urea nozzle unclogging device provided in this embodiment can execute the urea nozzle unclogging method of the above embodiment, and its implementation principle and technical effects are similar, which will not be described in detail in this embodiment.

[0189] In the specific implementation of the aforementioned urea nozzle unclogging device, each module may be implemented as a processor, and the processor may execute computer-executable instructions stored in a memory, so that the processor executes the aforementioned urea nozzle unclogging method.

[0190] Figure 6 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 6 As shown, the electronic device 60 includes: at least one processor 601 and a memory 602. The electronic device 60 also includes a communication component 603. The processor 601, the memory 602 and the communication component 603 are connected via a bus 604.

[0191] In a specific implementation process, at least one processor 601 executes the computer-executable instructions stored in the memory 602 , so that the at least one processor 601 executes the urea nozzle unclogging method executed by the electronic device side as described above.

[0192] The specific implementation process of the processor 601 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0193] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0194] The memory may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk storage.

[0195] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0196] The above-mentioned functions implemented by the electronic device and the main control device have introduced the solutions provided by the embodiments of the present invention. It can be understood that in order to implement the above-mentioned functions, the electronic device or the main control device includes hardware structures and / or software modules corresponding to the execution of each function. In combination with the units and algorithm steps of the various examples described in the embodiments disclosed in the embodiments of the present invention, the embodiments of the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solution of the embodiments of the present invention.

[0197] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above-mentioned urea nozzle unclogging method is implemented.

[0198] The computer-readable storage medium mentioned above can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk. The computer-readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0199] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in an electronic device or a main control device.

[0200] The present application also provides a computer program product, which includes: a computer program, which is 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 at least one processor executes the computer program so that the electronic device executes the solution provided by any of the above embodiments.

[0201] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for unclogging a urea nozzle, characterized in that: The method comprises: When it is determined that the urea nozzle is clogged, unblocking the urea nozzle according to a urea system injection strategy, and determining whether the urea system injection strategy unblocks the urea nozzle; If it is determined that the urea system injection strategy has not unblocked the urea nozzle, determining a crystallization state of the urea nozzle based on the pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state being used to indicate that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state being used to indicate that the blocking crystals are one or more of ammeline and ammelide; determining a target fuel injection amount according to the crystallization state, and controlling the HCI system to unclog the urea nozzle according to the target fuel injection amount; The determining the crystallization state of the urea nozzle according to the pre-SCR temperature includes: Obtaining an average value of the temperature before the SCR within a preset sampling time period as a first average temperature; If the first average temperature is not greater than a first preset temperature, determining that the crystallization state of the urea nozzle is the first state; If the first average temperature is greater than a first preset temperature and not greater than a sixth preset temperature, determining that the crystallization state of the urea nozzle is the second state; If the first average temperature is greater than a sixth preset temperature, determining a crystallization state of the urea nozzle according to the pre-SCR temperature within a third preset time period; Wherein, the first preset temperature is lower than the sixth preset temperature; The determining the crystallization state of the urea nozzle according to the pre-SCR temperature within a third preset time period includes: Obtaining a cumulative time during which the pre-SCR temperature is greater than a fifth preset temperature within a third preset time period as a third cumulative time; wherein the sixth preset temperature is less than the fifth preset temperature; If the third accumulated time is not greater than a fourth preset time and the urea nozzle is clogged, determining that the crystallization state of the urea nozzle is the second state; If the third accumulated time is not greater than the fourth preset time and the urea nozzle is not blocked, it is determined that the urea nozzle has been unblocked; If the third accumulated time is greater than the fourth preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to a driver console.

2. The method according to claim 1, characterized in that If it is determined that the crystallization state is the first state, determining a target fuel injection amount according to the crystallization state, and controlling the HCI system to unclog the urea nozzle according to the target fuel injection amount include: Determining a first target fuel injection amount based on a second preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel based on the first target fuel injection amount; the second preset temperature being a target temperature of the DPF; Obtaining a first accumulated time during which the pre-SCR temperature is not less than a third preset temperature; Whether the urea nozzle is unblocked is determined according to the first accumulated time.

3. The method according to claim 2, characterized in that The determining whether the urea nozzle is unblocked according to the first accumulated time includes: If the first accumulated time is not less than the first preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and the crystallization state is determined to be the second state; If the first accumulated time is less than the first preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked, and the fuel injection is stopped.

4. The method according to claim 1, wherein If it is determined that the crystallization state is the second state, determining a target fuel injection amount according to the crystallization state, and controlling the HCI system to unclog the urea nozzle according to the target fuel injection amount include: determining a second target fuel injection amount according to a fourth preset temperature, a pre-DOC temperature, and a post-DOC temperature; controlling the HCI injection system to inject fuel according to the second target fuel injection amount, wherein the fourth preset temperature is a target temperature of the DPF; acquiring a second accumulated time during which the pre-SCR temperature is not less than a fifth preset temperature; Whether the urea nozzle is unblocked is determined according to the second accumulated time.

5. The method according to claim 4, characterized in that The determining whether the urea nozzle is unblocked according to the second accumulated time includes: If the second accumulated time is not less than the second preset time and the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked, and a message indicating a urea nozzle failure is sent to the driver console; If the second accumulated time is less than the second preset time and the urea nozzle is not clogged, it is determined that the urea nozzle is unblocked, and the fuel injection is stopped.

6. The method according to claim 1, wherein The urea nozzle is unblocked according to the urea system injection strategy, comprising: Controlling the urea system to perform one or more injections according to a preset duty cycle, a preset injection duration, and a preset rest time; The determining whether the urea system injection strategy unclogs the urea nozzle includes: If the number of injections of the urea system is not greater than a preset number and it is determined that the urea nozzle is not blocked, it is determined that the urea nozzle is unblocked; If the number of injections of the urea system is greater than a preset number and it is determined that the urea nozzle is clogged, it is determined that the urea nozzle is not unblocked.

7. A urea nozzle dredging device, used in the urea nozzle dredging method according to any one of claims 1 to 6, characterized in that: include: The first module is configured to, when determining that the urea nozzle is clogged, unclog the urea nozzle according to a urea system injection strategy, and determine whether the urea system injection strategy unclogs the urea nozzle; a second module configured to, if it is determined that the urea system injection strategy has not unblocked the urea nozzle, determine a crystallization state of the urea nozzle based on a pre-SCR temperature; wherein the crystallization state includes a first state and a second state, the first state being used to indicate that the blocking crystals are one or more of biuret, urea, and cyanuric acid, and the second state being used to indicate that the blocking crystals are one or more of ammeline and ammelide; The third module is configured to determine a target fuel injection amount according to the crystallization state, and control the HCI system to unclog the urea nozzle according to the target fuel injection amount.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

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