Urea injection system siphoning method, device, computer device and storage medium

Abstract

The application discloses a urea injection system back-suction method, a urea injection system back-suction device, computer equipment and a computer storage medium. The urea injection system back-suction method comprises the following steps: in response to a urea injection system back-suction emptying instruction, it is judged whether a preset condition is met, the preset condition is used to represent that the urea injection system can normally work in the state that urea exists in the pipeline of the urea injection system; according to the fact that the preset condition is met, the urea injection system is controlled to perform incomplete back-suction emptying; and in response to vehicle starting, the urea injection system is controlled to perform front back-suction emptying. The urea injection system back-suction method can reduce the damage of high-temperature exhaust gas to the urea injection system.

Description

Technical Field

[0001] This invention relates to the field of vehicle aftertreatment technology, and in particular to a method for back-suction of a urea injection system, a device for back-suction of a urea injection system, a computer device, and a computer storage medium. Background Technology

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

[0003] Existing diesel engines use a urea injection system to inject urea into the exhaust gas, thereby reducing the content of nitrogen oxides in the exhaust. During backflow venting, the urea injection system activates a pump to draw excess urea back into the urea tank.

[0004] When a urea injection system back-suctions and empties, high-temperature exhaust gas from the exhaust pipe is drawn into the urea injection system, causing damage to the system's piping and nozzles. However, in existing technologies, the back-suction and emptying pattern of the urea injection system is fixed, resulting in significant damage from the exhaust gas. Summary of the Invention

[0005] The objective of this invention is to at least solve the problem of significant damage caused by exhaust gas to urea injection systems in existing technologies. This objective is achieved through the following technical solution:

[0006] A first aspect of the present invention provides a method for backflow in a urea injection system, comprising:

[0007] In response to the back-suction and emptying command of the urea injection system, it is determined whether a preset condition is met. The preset condition is used to characterize the state in which urea exists in the pipeline of the urea injection system, and the urea injection system can work normally.

[0008] Based on the preset conditions being met, the urea injection system is controlled to perform incomplete post-absorption and evacuation.

[0009] In response to vehicle startup, the urea injection system is controlled to perform pre-suction backflow evacuation.

[0010] The urea injection system back-suction method of the present invention can rationally select the execution strategy for back-suction by judging whether preset conditions are met. When the preset conditions are met, by performing incomplete post-back-suction evacuation, the back-suction evacuation time can be reduced, thereby reducing the amount of high-temperature exhaust gas drawn into the urea injection system pipeline and thus reducing the damage of exhaust gas to the urea injection system pipeline. In addition, the residual urea in the urea injection system pipeline can isolate the exhaust gas from the pipeline to a certain extent, thereby further reducing the damage of exhaust gas to the urea injection system pipeline. Furthermore, the residual urea in the urea injection system pipeline can absorb the heat of the exhaust gas, thereby playing a buffering and heat dissipation role, thereby further reducing the damage of exhaust gas to the urea injection system pipeline. After incomplete post-back-suction evacuation, some urea remains in the urea injection system pipeline. When the vehicle is running, performing front-back-suction evacuation can treat the residual urea in the urea injection system pipeline. When the vehicle is running, the temperature of the exhaust gas in the exhaust pipe is relatively low. Therefore, during the front-mounted reverse suction venting, the exhaust gas causes less damage to the urea injection system piping. Thus, the reverse suction method for the urea injection system of this invention can reduce the damage to the urea injection system caused by high-temperature exhaust gas.

[0011] In some embodiments, the urea injection system backflow method further includes:

[0012] If the preset conditions are not met, the urea injection system is controlled to perform a complete back-suction and emptying.

[0013] In some embodiments, the step of controlling the urea injection system to perform pre-emptive backflow evacuation in response to vehicle start-up includes:

[0014] In response to vehicle startup, the temperature of the exhaust gas entering the selective catalytic reduction system is acquired, and the exhaust gas temperature is compared with a temperature threshold.

[0015] Based on the fact that the exhaust gas temperature is greater than the temperature threshold, the urea injection system is controlled to perform incomplete pre-sumption back-suction and venting.

[0016] Based on the exhaust gas temperature being less than or equal to the temperature threshold, the urea injection system is controlled to perform complete pre-sumption backflow venting.

[0017] In some embodiments, the time for complete post-back suction emptying is t, the time for incomplete post-back suction emptying is t1, the time for incomplete pre-back suction emptying is t2, and the time for complete pre-back suction emptying is t3, where t = t1 + t3 and t > t1 + t2.

[0018] In some embodiments, the step of determining whether a preset condition is met includes:

[0019] Determine if there is an unfreezing request;

[0020] Based on the existence of the aforementioned unfreezing request, it is determined that the preset conditions are not met;

[0021] Based on the absence of the aforementioned unfreezing request, it is determined that the preset condition is met.

[0022] In some embodiments, the step of determining whether a preset condition is met further includes:

[0023] Obtain the ambient temperature and compare it with a preset ambient temperature value;

[0024] The step of determining that the preset condition is not met based on the existence of the unfreezing request includes:

[0025] Based on the existence of the thawing request, and / or based on the fact that the ambient temperature is less than or equal to the preset ambient temperature value, it is determined that the preset condition is not met;

[0026] The step of determining whether the preset condition is met based on the absence of the unfreezing request includes:

[0027] Based on the absence of the thawing request and the fact that the ambient temperature is greater than the preset ambient temperature value, it is determined that the preset condition is met.

[0028] In some embodiments, the step of determining whether a preset condition is met further includes:

[0029] Obtain the system stiffness of the urea injection system and compare the system stiffness with a preset system stiffness value;

[0030] The step of determining that the preset condition is not met based on the existence of the thawing request and / or based on the ambient temperature being less than or equal to a preset ambient temperature value includes:

[0031] Based on the existence of the thawing request, and / or based on the fact that the ambient temperature is less than or equal to the preset ambient temperature value, and / or based on the fact that the system stiffness is less than or equal to the preset system stiffness value, it is determined that the preset condition is not met;

[0032] The step of determining that the preset condition is met based on the absence of the thawing request and the ambient temperature being greater than the preset ambient temperature value includes:

[0033] Based on the absence of the thawing request, the ambient temperature being greater than the preset ambient temperature value, and the system stiffness being greater than the preset system stiffness value, it is determined that the preset conditions are met.

[0034] A second aspect of the present invention provides a backflow control device for a urea injection system, comprising:

[0035] The judgment module is used to respond to the back suction and emptying command of the urea injection system and determine whether the preset conditions are met. The preset conditions are used to indicate that the urea injection system can work normally when there is urea in the pipeline of the urea injection system.

[0036] The first control module is used to control the urea injection system to perform incomplete post-suction and venting according to the preset conditions.

[0037] The second control module is used to control the urea injection system to perform pre-suction venting in response to vehicle startup.

[0038] A third aspect of the present invention provides a computer device including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the urea injection system backflow method as described in the first aspect above.

[0039] A fourth aspect of the present invention provides a computer storage medium storing computer-readable instructions that, when read by one or more processors, cause one or more processors to perform the steps of the urea injection system backflow method as described in the first aspect above. Attached Figure Description

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0041] Figure 1 This is a schematic diagram of the backflow method of the urea injection system according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the back suction device of the urea injection system according to an embodiment of the present invention. Detailed Implementation

[0043] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0044] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0045] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0046] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0047] Existing diesel engines use a urea injection system to inject urea into the exhaust gas, thereby reducing the content of nitrogen oxides in the exhaust. During backflow venting, the urea injection system activates a pump to draw excess urea back into the urea tank.

[0048] When a urea injection system performs back-suction venting, high-temperature exhaust gas from the exhaust pipe is drawn into the system, potentially damaging the piping and nozzles. However, in existing technologies, the back-suction venting pattern is fixed. During back-suction venting, the system completely draws the urea back into the urea tank, causing the high-temperature exhaust gas to remain in contact with the piping and nozzles for an extended period, resulting in significant damage.

[0049] In order to at least address the problem of significant damage to urea injection systems caused by exhaust gas in existing technologies, embodiments of the present invention propose a back-suction method for urea injection systems, which can reduce the damage to urea injection systems caused by high-temperature exhaust gas.

[0050] The method for backflow of urea injection system according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0051] like Figure 1 As shown, the urea injection system backflow method of this embodiment includes:

[0052] S100. In response to the back suction and emptying command of the urea injection system, determine whether the preset conditions are met. The preset conditions are used to characterize the state in which urea exists in the pipeline of the urea injection system, and the urea injection system can work normally.

[0053] S200: Based on the preset conditions, control the urea injection system to perform incomplete back-suction and venting.

[0054] S300, in response to vehicle start-up, controls the urea injection system to perform front-mounted back-suction venting.

[0055] S100: In response to the back suction and venting command of the urea injection system, determine whether the preset conditions are met. The preset conditions are used to characterize the state in which urea exists in the pipeline of the urea injection system, and the urea injection system can work normally.

[0056] If the urea injection system functions normally while urea is present in its pipeline, it indicates that some urea may remain in the pipeline after back-suction evacuation. Conversely, if the urea injection system fails to function normally while urea is present in its pipeline, it indicates that there should be no urea or almost no urea remaining in the pipeline after back-suction evacuation. Therefore, by determining whether the preset conditions are met, a reasonable strategy for back-suction evacuation can be selected.

[0057] In some embodiments, the step of determining whether a preset condition is met includes:

[0058] Determine if there is an unfreezing request;

[0059] Based on the existence of a defrost request, it is determined that the preset conditions are not met.

[0060] Based on the absence of an unfreezing request, the preset conditions are deemed met.

[0061] The presence of a thawing request indicates that the temperature is too low, posing a significant risk of urea freezing. If urea remains in the urea injection system's piping, it can easily cause blockages in the piping and nozzles. Furthermore, low temperatures reduce urea solubility, increasing the risk of crystallization and further exacerbating blockages in the piping and nozzles. In other words, even with a thawing request in place, the presence of urea in the injection system's piping can prevent the system from functioning properly.

[0062] If a thawing request exists, it is determined that the preset conditions are not met; if no thawing request exists, it is determined that the preset conditions are met. This ensures the normal operation of the urea injection system and enables the judgment of preset conditions, thereby allowing for the reasonable selection of the venting and backflow execution strategy in subsequent steps.

[0063] In some embodiments, the step of determining whether a preset condition is met further includes:

[0064] Obtain the ambient temperature and compare it with the preset ambient temperature value;

[0065] Based on the existence of an unfreezing request, it is determined that the preset conditions are not met, including:

[0066] Based on the existence of a thawing request, and / or based on the ambient temperature being less than or equal to a preset ambient temperature value, it is determined that the preset conditions are not met;

[0067] Based on the absence of an unfreezing request, the system determines that preset conditions are met, including:

[0068] Based on the absence of a defrost request and the ambient temperature being greater than the preset ambient temperature value, the preset conditions are determined to be met.

[0069] In other words, if at least one of the following conditions exists—a thawing request exists and the ambient temperature is less than or equal to a preset ambient temperature value—then the preset condition is determined not to be met. If neither of the following conditions exists—a thawing request exists and the ambient temperature is greater than the preset ambient temperature value—then the preset condition is determined to be met.

[0070] As some examples, the ambient temperature is preset to 5 degrees Celsius.

[0071] The presence of a thawing request and an ambient temperature less than or equal to a preset ambient temperature both indicate that the temperature is too low, posing a significant risk of urea freezing. If urea remains in the urea injection system's piping, it can easily cause blockages in the piping and nozzles. Furthermore, low temperatures reduce urea solubility, increasing the risk of crystallization and further exacerbating blockages in the piping and nozzles. In other words, under conditions of a thawing request and / or an ambient temperature less than or equal to a preset ambient temperature, the presence of urea in the urea injection system's piping can prevent the system from functioning properly.

[0072] If a thawing request exists, and / or if the ambient temperature is less than or equal to a preset ambient temperature value, it is determined that the preset conditions are not met; if no thawing request exists, and the ambient temperature is greater than the preset ambient temperature value, it is determined that the preset conditions are met. This ensures the normal operation of the urea injection system and enables the judgment of preset conditions, thereby allowing for the reasonable selection of the venting and backflow execution strategy in subsequent steps. It also optimizes the judgment based on multiple judgment conditions, thereby improving the accuracy of temperature judgment.

[0073] In some embodiments, the step of determining whether a preset condition is met further includes:

[0074] Obtain the system stiffness of the urea injection system and compare it with the preset system stiffness value;

[0075] Based on the existence of a thawing request, and / or based on the ambient temperature being less than or equal to a preset ambient temperature value, it is determined that the preset conditions are not met, including:

[0076] Based on the existence of a thawing request, and / or based on the ambient temperature being less than or equal to a preset ambient temperature value, and / or based on the system stiffness being less than or equal to a preset system stiffness value, it is determined that the preset conditions are not met;

[0077] Based on the absence of a defrost request and the ambient temperature being greater than a preset value, the preset conditions are determined to be met, including:

[0078] Based on the absence of a thawing request, the ambient temperature being greater than the preset ambient temperature value, and the system stiffness being greater than the preset system stiffness value, it is determined that the preset conditions are met.

[0079] If a thawing request exists, and the ambient temperature is less than or equal to the preset ambient temperature value, and the system stiffness is less than or equal to the preset system stiffness value, and at least one of these conditions is met, it is determined that the preset conditions are not met.

[0080] There is no thawing request, the ambient temperature is greater than the preset ambient temperature value, and the system stiffness is greater than the preset system stiffness value. If each of these conditions is met, the preset conditions are satisfied.

[0081] The system stiffness of a urea injection system indicates its ability to resist deformation. Higher system stiffness results in greater fluctuations during pressure build-up, thus reducing the control precision of urea injection.

[0082] As some examples, the system stiffness is preset to 8 N / mm.

[0083] If the system stiffness exceeds the preset value, it indicates that the system stiffness is too high. When urea is present in the urea injection system's pipeline, the pressure build-up of the urea pump fluctuates significantly. This forces the pipeline to withstand unstable pressure surges from the urea pump, potentially leading to pipeline damage. Furthermore, large pressure build-up fluctuations in the urea pump also reduce the control accuracy of urea injection. In other words, when the system stiffness exceeds the preset value, the presence of even a small amount of urea in the pipeline can cause the urea injection system to malfunction.

[0084] Based on the absence of a thawing request, the ambient temperature being greater than the preset ambient temperature value, and the system stiffness being greater than the preset system stiffness value, it is determined that the preset conditions are met. The system can optimize the judgment based on multiple conditions to ensure the normal operation of the urea injection system and can also judge the preset conditions, thereby enabling the reasonable selection of the venting and backflow execution strategy in subsequent steps.

[0085] S200: Based on the preset conditions, control the urea injection system to perform incomplete back-suction and venting.

[0086] Incomplete post-back suction evacuation refers to the process where back suction evacuation is performed after the urea injection system has completed its normal injection operation. After incomplete post-back suction evacuation, some urea remains in the pipes of the urea injection system.

[0087] When the preset conditions are met, the time for incomplete back-suction evacuation can be reduced by performing incomplete back-suction evacuation, thereby reducing the amount of high-temperature exhaust gas drawn into the pipeline of the urea injection system and thus reducing the damage of the exhaust gas to the pipeline of the urea injection system.

[0088] In addition, the residual urea in the pipeline of the urea injection system can isolate the exhaust gas from the pipeline to a certain extent, thereby further reducing the damage of the exhaust gas to the pipeline of the urea injection system.

[0089] In addition, the residual urea in the urea injection system's pipeline can absorb the heat from the exhaust gas, thus playing a buffering and heat dissipation role, which can further reduce the damage of the exhaust gas to the urea injection system's pipeline.

[0090] In some optional embodiments, S200, based on satisfying preset conditions, controls the urea injection system to perform incomplete post-absorption and evacuation, including...

[0091] Based on the preset conditions, the ambient temperature is obtained, and the duration of incomplete post-back suction is obtained based on the ambient temperature. The duration of incomplete post-back suction is negatively correlated with the ambient temperature.

[0092] Incomplete post-absorption and evacuation are controlled by duration.

[0093] The time for incomplete backflow and emptying is negatively correlated with ambient temperature. That is, the higher the ambient temperature, the shorter the time for incomplete backflow and emptying, and the lower the ambient temperature, the longer the time for incomplete backflow and emptying.

[0094] The lower the temperature, the higher the risk of urea crystallization. Therefore, at lower temperatures, increasing the duration of incomplete post-absorption evacuation reduces the amount of urea remaining in the urea injection system's pipeline, thereby lowering the probability of the pipeline and nozzle of the urea injection system becoming clogged.

[0095] The higher the temperature, the lower the risk of urea crystallization. Therefore, at higher temperatures, the duration of incomplete post-absorption venting is reduced, the contact time between exhaust gas and pipeline is decreased, and the residual urea in the pipeline of the urea injection system is increased to increase the urea isolation area for exhaust gas and increase the temperature at which urea absorbs exhaust gas, thereby further reducing the damage of exhaust gas to the pipeline of the urea injection system.

[0096] Therefore, through this embodiment, the duration of incomplete back suction and emptying can be reasonably determined, and incomplete back suction and emptying can be controlled according to the duration.

[0097] In some alternative embodiments, S200, according to the satisfaction of preset conditions, controls the urea injection system to perform incomplete post-absorption and evacuation, including:

[0098] Obtain the temperature and flow rate of the exhaust gas entering the SCR (Selective Catalytic Reduction) system;

[0099] The duration of incomplete post-back suction venting is obtained based on the exhaust gas temperature, exhaust gas flow rate, and first duration array. The first duration array is a preset three-dimensional array, which is a mapping array of exhaust gas temperature, exhaust gas flow rate, and duration.

[0100] The first duration array is a mapping array of exhaust gas temperature, exhaust gas flow rate and duration. This means that in the first duration array, each set of exhaust gas temperature and exhaust gas flow rate corresponds to a duration, and each set of exhaust gas temperature and exhaust gas flow rate includes an exhaust gas temperature and an exhaust gas flow rate.

[0101] Through this embodiment, after obtaining the exhaust gas temperature and exhaust gas flow rate, the duration of incomplete back suction and venting can be quickly determined, and incomplete back suction and venting can be controlled according to the duration.

[0102] S300, in response to vehicle start-up, controls the urea injection system to perform front-mounted back-suction venting.

[0103] Pre-suction evacuation refers to the process of evacuating the urea before the urea injection system completes its normal injection operation.

[0104] After incomplete rear-draft evacuation, some urea remains in the urea injection system's lines. Performing front-draft evacuation while the vehicle is running helps to remove this residual urea. When the vehicle is running, the exhaust gas temperature in the exhaust pipe is relatively low, minimizing damage to the urea injection system's lines during front-draft evacuation.

[0105] In some embodiments, S300, the step of controlling the urea injection system to perform pre-sucking evacuation in response to vehicle start-up, includes:

[0106] In response to vehicle startup, the temperature of the exhaust gas entering the selective catalytic reduction system is obtained and compared with a temperature threshold.

[0107] If the exhaust gas temperature is greater than the temperature threshold, incomplete pre-sumption back-suction is controlled to exhaust the gas.

[0108] Based on the exhaust gas temperature being less than or equal to a temperature threshold, complete pre-sumption backflow is controlled for venting.

[0109] As an example, the temperature threshold is 160 degrees Celsius.

[0110] Incomplete pre-vacuuming refers to the process where the pre-vacuuming is performed before the urea injection system completes its normal injection operation, and after incomplete pre-vacuuming, some urea remains in the pipeline of the urea injection system.

[0111] Complete pre-vacuuming means that the pre-vacuuming is performed before the urea injection system completes normal injection. After complete pre-vacuuming, there is no urea or almost no urea in the pipeline of the urea injection system.

[0112] If the exhaust gas temperature is higher than the temperature threshold, it indicates that the exhaust gas temperature is relatively high. When the exhaust gas enters the urea injection system, it can damage the pipeline of the urea injection system. Therefore, incomplete pre-suction venting is performed to reduce the venting time and reduce the amount of high-temperature exhaust gas drawn into the pipeline of the urea injection system, thereby reducing the damage to the pipeline of the urea injection system caused by the exhaust gas.

[0113] In addition, the residual urea in the urea injection system's pipeline can isolate the exhaust gas from the pipeline to a certain extent, thereby further reducing the damage of the exhaust gas to the urea injection system's pipeline.

[0114] In addition, the residual urea in the urea injection system's pipeline can absorb the heat from the exhaust gas, thus playing a buffering and heat dissipation role, which can further reduce the damage of the exhaust gas to the urea injection system's pipeline.

[0115] If the exhaust gas temperature is lower than the temperature threshold, it means that the exhaust gas temperature is relatively low. When the exhaust gas enters the urea injection system, it will not cause damage to the pipeline of the urea injection system. Therefore, complete pre-sumption and back-suction are performed.

[0116] In some alternative embodiments, the urea injection system is controlled to perform incomplete pre-absorption evacuation, including...

[0117] Based on the preset conditions, the ambient temperature is obtained, and the duration of incomplete pre-sinking is obtained based on the ambient temperature. The duration of incomplete pre-sinking is negatively correlated with the ambient temperature.

[0118] Incomplete pre-sucking and emptying is performed based on duration control.

[0119] The time for incomplete backflow and emptying is negatively correlated with ambient temperature. That is, the higher the ambient temperature, the shorter the time for incomplete backflow and emptying, and the lower the ambient temperature, the longer the time for incomplete backflow and emptying.

[0120] The lower the temperature, the higher the risk of urea crystallization. Therefore, at lower temperatures, increasing the duration of incomplete pre-suction evacuation reduces the amount of urea remaining in the urea injection system's pipeline, thereby lowering the probability of the pipeline and nozzle of the urea injection system becoming clogged.

[0121] The higher the temperature, the lower the risk of urea crystallization. Therefore, at higher temperatures, the duration of incomplete pre-suction venting is reduced, the contact time between exhaust gas and pipeline is decreased, and the residual urea in the pipeline of the urea injection system is increased to increase the urea isolation area for exhaust gas and increase the temperature at which urea absorbs exhaust gas, thereby further reducing the damage of exhaust gas to the pipeline of the urea injection system.

[0122] Therefore, through this embodiment, the duration of incomplete back suction and emptying can be reasonably determined, and incomplete back suction and emptying can be controlled according to the duration.

[0123] In some alternative embodiments, controlling the urea injection system to perform incomplete pre-absorption evacuation includes:

[0124] Obtain the temperature and flow rate of the exhaust gas entering the SCR;

[0125] The duration of incomplete pre-sumption evacuation is obtained based on the exhaust gas temperature, exhaust gas flow rate, and second duration array. The second duration array is a preset three-dimensional array, which is a mapping array of exhaust gas temperature, exhaust gas flow rate, and duration.

[0126] The second duration array is a mapping array of exhaust gas temperature, exhaust gas flow rate and duration. This means that in the second duration array, each set of exhaust gas temperature and exhaust gas flow rate corresponds to a duration, and each set of exhaust gas temperature and exhaust gas flow rate includes an exhaust gas temperature and an exhaust gas flow rate.

[0127] Through this embodiment, after obtaining the exhaust gas temperature and exhaust gas flow rate, the duration of incomplete back suction and venting can be quickly determined, and incomplete back suction and venting can be controlled according to the duration.

[0128] The urea injection system back-suction method of this invention can rationally select the execution strategy for back-suction by determining whether preset conditions are met. When the preset conditions are met, by performing incomplete post-back-suction evacuation, the back-suction evacuation time can be reduced, thereby reducing the amount of high-temperature exhaust gas drawn into the urea injection system pipeline and thus reducing the damage to the pipeline caused by exhaust gas. Furthermore, the residual urea in the pipeline can, to some extent, isolate the exhaust gas from the pipeline, further reducing the damage to the pipeline caused by exhaust gas. Additionally, the residual urea in the pipeline can absorb the heat of the exhaust gas, thus acting as a buffer and heat dissipation agent, further reducing the damage to the pipeline caused by exhaust gas. After incomplete post-back-suction evacuation, some urea remains in the pipeline. When the vehicle is running, performing front-back-suction evacuation can treat the residual urea in the pipeline. When the vehicle is running, the temperature of the exhaust gas in the exhaust pipe is relatively low. Therefore, during the front-mounted reverse suction venting, the exhaust gas causes less damage to the urea injection system piping. Thus, the reverse suction method for the urea injection system of this invention can reduce the damage to the urea injection system caused by high-temperature exhaust gas.

[0129] In some embodiments, the urea injection system backflow method further includes:

[0130] If the preset conditions are not met, the urea injection system is controlled to perform a complete back-suction and emptying.

[0131] Complete post-reverse suction evacuation means that the reverse suction evacuation is carried out after the urea injection system has completed its normal injection operation, and after complete post-reverse suction evacuation, there is no urea or almost no urea in the pipeline of the urea injection system.

[0132] If the preset conditions are not met, and urea is present in the pipeline of the urea injection system, the urea injection system cannot work normally. Therefore, a complete back-suction venting is performed to allow the urea injection system to operate normally.

[0133] In some embodiments, the time for complete post-back suction emptying is t, the time for incomplete post-back suction emptying is t1, the time for incomplete pre-back suction emptying is t2, and the time for complete pre-back suction emptying is t3, where t = t1 + t3 and t > t1 + t2.

[0134] The formula t = t1 + t3 allows for more thorough purging of the pipeline in the urea injection system.

[0135] The time between exhaust gas and pipeline can be reduced by t > t1 + t2, and the amount of residual urea in the pipeline of the urea injection system can be increased to increase the area of ​​urea that isolates exhaust gas and increase the temperature at which urea absorbs exhaust gas, thereby further reducing the damage of exhaust gas to the pipeline of the urea injection system.

[0136] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0137] Based on the same inventive concept, this application also provides a urea injection system backflow control device 1 for implementing the urea injection system backflow control method described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the urea injection system backflow control device 1 provided below can be found in the limitations of the urea injection system backflow control method described above, and will not be repeated here.

[0138] like Figure 2 As shown, the urea injection system backflow control device 1 of this embodiment includes:

[0139] The judgment module 100 is used to respond to the back suction and emptying command of the urea injection system and determine whether the preset conditions are met. The preset conditions are used to characterize the state in which urea exists in the pipeline of the urea injection system and the urea injection system can work normally.

[0140] The first control module 200 is used to control the urea injection system to perform incomplete post-back suction and venting according to the preset conditions.

[0141] The second control module 300 is used to control the urea injection system to perform front-mounted back suction and venting in response to vehicle startup.

[0142] The urea injection system back-suction control device 1 of this invention, through the judgment module 100 determining whether preset conditions are met, can rationally select the execution strategy for back-suction evacuation. When the preset conditions are met, the first control module 200 performs incomplete post-back-suction evacuation, thereby reducing the back-suction evacuation time and decreasing the amount of high-temperature exhaust gas drawn into the urea injection system pipeline, thus reducing damage to the pipeline caused by the exhaust gas. Furthermore, the residual urea in the pipeline can, to some extent, isolate the exhaust gas from the pipeline, further reducing damage to the pipeline caused by the exhaust gas. Additionally, the residual urea in the pipeline can absorb heat from the exhaust gas, thus acting as a buffer and heat dissipation agent, further reducing damage to the pipeline caused by the exhaust gas. After incomplete rear-draft evacuation, some urea remains in the urea injection system's piping. With the vehicle running, the second control module 300 controls front-draft evacuation to remove this residual urea. When the vehicle is running, the exhaust gas temperature is relatively low, minimizing damage to the urea injection system's piping during front-draft evacuation. This reduces the damage caused by high-temperature exhaust gas to the urea injection system.

[0143] In some embodiments, the urea injection system backflow control device further includes a third control module for:

[0144] If the preset conditions are not met, the urea injection system is controlled to perform a complete back-suction and emptying.

[0145] In some embodiments, the second control module 300 is further configured to:

[0146] In response to vehicle startup, the temperature of the exhaust gas entering the selective catalytic reduction system is obtained and compared with a temperature threshold.

[0147] Based on the exhaust gas temperature being greater than the temperature threshold, the urea injection system is controlled to perform incomplete pre-sumption and back-suction.

[0148] Based on the exhaust gas temperature being less than or equal to a temperature threshold, the urea injection system is controlled to perform complete pre-sumption backflow and venting.

[0149] In some embodiments, the time for complete post-back suction emptying is t, the time for incomplete post-back suction emptying is t1, the time for incomplete pre-back suction emptying is t2, and the time for complete pre-back suction emptying is t3, where t = t1 + t3 and t > t1 + t2.

[0150] In some embodiments, the determining module 100 is further configured to:

[0151] Determine if there is an unfreezing request;

[0152] Based on the existence of a defrost request, it is determined that the preset conditions are not met.

[0153] Based on the absence of an unfreezing request, the preset conditions are deemed met.

[0154] In some embodiments, the determining module 100 is further configured to:

[0155] Obtain the ambient temperature and compare it with the preset ambient temperature value;

[0156] Based on the existence of a thawing request, and / or based on the ambient temperature being less than or equal to a preset ambient temperature value, it is determined that the preset conditions are not met;

[0157] Based on the absence of a defrost request and the ambient temperature being greater than the preset ambient temperature value, the preset conditions are determined to be met.

[0158] In some embodiments, the determining module 100 is further configured to:

[0159] Obtain the system stiffness of the urea injection system and compare it with the preset system stiffness value;

[0160] Based on the existence of a thawing request, and / or based on the ambient temperature being less than or equal to a preset ambient temperature value, and / or based on the system stiffness being less than or equal to a preset system stiffness value, it is determined that the preset conditions are not met;

[0161] Based on the absence of a thawing request, the ambient temperature being greater than the preset ambient temperature value, and the system stiffness being greater than the preset system stiffness value, it is determined that the preset conditions are met.

[0162] Embodiments of the present invention also propose a computer device.

[0163] The computer device of this invention includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the urea injection system backflow method as described in the above embodiment.

[0164] The computer device of this invention, when the processor executes the computer program, implements the urea injection system back-suction method as described above. By determining whether preset conditions are met, the execution strategy for back-suction can be reasonably selected. When the preset conditions are met, by performing incomplete post-back-suction evacuation, the back-suction evacuation time can be reduced, thereby reducing the amount of high-temperature exhaust gas drawn into the urea injection system pipeline and thus reducing damage to the urea injection system pipeline caused by the exhaust gas. Furthermore, the residual urea in the urea injection system pipeline can, to a certain extent, isolate the exhaust gas from the pipeline, further reducing damage to the urea injection system pipeline caused by the exhaust gas. Additionally, the residual urea in the urea injection system pipeline can absorb the heat of the exhaust gas, thus playing a buffering and heat dissipation role, further reducing damage to the urea injection system pipeline caused by the exhaust gas. After incomplete post-back-suction evacuation, some urea remains in the urea injection system pipeline. When the vehicle is running, performing front-back-suction evacuation can treat the residual urea in the urea injection system pipeline. When the vehicle is running, the temperature of the exhaust gas in the exhaust pipe is relatively low. During the front-mounted reverse suction venting, the exhaust gas causes less damage to the urea injection system's piping. This reduces the damage to the urea injection system caused by high-temperature exhaust gas.

[0165] Furthermore, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the aforementioned urea injection system backflow control method.

[0166] Embodiments of the present invention also propose a computer storage medium.

[0167] The computer storage medium of this invention stores computer-readable instructions. When the computer-readable instructions are read by one or more processors, the one or more processors cause the one or more processors to execute the steps of the urea injection system back suction method as described in the above embodiment.

[0168] In this embodiment of the invention, when computer-readable instructions are read by one or more processors, the processors execute the steps of the urea injection system back-suction method as described above. By determining whether preset conditions are met, the execution strategy for back-suction can be rationally selected. When the preset conditions are met, by performing incomplete post-back-suction, the back-suction time can be reduced, thereby reducing the amount of high-temperature exhaust gas drawn into the urea injection system pipeline and thus reducing damage to the pipeline caused by the exhaust gas. Furthermore, the residual urea in the pipeline can isolate the exhaust gas from the pipeline to a certain extent, further reducing damage to the pipeline caused by the exhaust gas. Additionally, the residual urea in the pipeline can absorb heat from the exhaust gas, thus acting as a buffer and heat dissipation agent, further reducing damage to the pipeline caused by the exhaust gas. After incomplete rear-draft evacuation, some urea remains in the urea injection system's lines. Performing front-draft evacuation while the vehicle is running helps to remove this residual urea. When the vehicle is running, the exhaust gas temperature in the exhaust pipe is relatively low, minimizing damage to the urea injection system lines during front-draft evacuation. This reduces the damage caused by high-temperature exhaust gases to the urea injection system.

[0169] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections (electronic devices) having one or more wires, portable computer disks (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM, or flash memory), fiber optic devices, and compact disc read-only memory (CDROM). Furthermore, computer-readable storage media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0170] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0171] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for backflow in a urea injection system, characterized in that, include: In response to the back-suction and emptying command of the urea injection system, it is determined whether a preset condition is met. The preset condition is used to characterize the state in which urea exists in the pipeline of the urea injection system, and the urea injection system can work normally. Based on the preset conditions being met, the urea injection system is controlled to perform incomplete post-absorption and evacuation. In response to vehicle startup, the urea injection system is controlled to perform front-mounted back-suction venting. The urea injection system backflow method further includes: If the preset conditions are not met, the urea injection system is controlled to perform complete post-sucking and emptying. The step of controlling the urea injection system to perform pre-sucking evacuation in response to vehicle start-up includes: In response to vehicle startup, the temperature of the exhaust gas entering the selective catalytic reduction system is acquired, and the exhaust gas temperature is compared with a temperature threshold. Based on the fact that the exhaust gas temperature is greater than the temperature threshold, the urea injection system is controlled to perform incomplete pre-sumption back-suction and venting. Based on the exhaust gas temperature being less than or equal to the temperature threshold, the urea injection system is controlled to perform complete pre-sucking and venting. The time for complete post-back suction and emptying is t, the time for incomplete post-back suction and emptying is t1, the time for incomplete pre-back suction and emptying is t2, and the time for complete pre-back suction and emptying is t3, where t = t1 + t3, and t > t1 + t2. Among them, pre-sucking and emptying refers to the back-sucking and emptying performed before the urea injection system completes normal injection work; Incomplete pre-vacuuming refers to the back-vacuuming performed before the urea injection system completes normal injection. After incomplete pre-vacuuming, some urea remains in the pipeline of the urea injection system. Complete pre-suction evacuation means that the urea injection system performs pre-suction evacuation before it completes normal injection, and after complete pre-suction evacuation, the urea in the pipeline of the urea injection system is completely emptied. Incomplete post-back suction evacuation refers to the back suction evacuation being carried out after the urea injection system has completed its normal injection operation. After incomplete post-back suction evacuation, some urea remains in the pipes of the urea injection system. Complete post-reverse suction evacuation refers to the process of performing reverse suction evacuation after the urea injection system has completed its normal injection operation. After performing complete post-reverse suction evacuation, the urea in the pipeline of the urea injection system is completely emptied.

2. The backflow method for the urea injection system according to claim 1, characterized in that, The step of determining whether the preset conditions are met includes: Determine if there is an unfreezing request; Based on the existence of the aforementioned unfreezing request, it is determined that the preset conditions are not met; Based on the absence of the aforementioned unfreezing request, it is determined that the preset condition is met.

3. The backflow method for the urea injection system according to claim 2, characterized in that, The step of determining whether the preset conditions are met further includes: Obtain the ambient temperature and compare it with a preset ambient temperature value; The step of determining that the preset condition is not met based on the existence of the unfreezing request includes: Based on the existence of the thawing request, and / or based on the fact that the ambient temperature is less than or equal to the preset ambient temperature value, it is determined that the preset condition is not met; The step of determining whether the preset condition is met based on the absence of the unfreezing request includes: Based on the absence of the thawing request and the fact that the ambient temperature is greater than the preset ambient temperature value, it is determined that the preset condition is met.

4. The backflow method for the urea injection system according to claim 3, characterized in that, The step of determining whether the preset conditions are met further includes: Obtain the system stiffness of the urea injection system and compare the system stiffness with a preset system stiffness value; The step of determining that the preset condition is not met based on the existence of the thawing request and / or based on the ambient temperature being less than or equal to a preset ambient temperature value includes: Based on the existence of the thawing request, and / or based on the fact that the ambient temperature is less than or equal to the preset ambient temperature value, and / or based on the fact that the system stiffness is less than or equal to the preset system stiffness value, it is determined that the preset condition is not met; The step of determining that the preset condition is met based on the absence of the thawing request and the ambient temperature being greater than the preset ambient temperature value includes: Based on the absence of the thawing request, the ambient temperature being greater than the preset ambient temperature value, and the system stiffness being greater than the preset system stiffness value, it is determined that the preset conditions are met.

5. A backflow control device for a urea injection system, characterized in that, include: The judgment module is used to respond to the back suction and emptying command of the urea injection system and determine whether the preset conditions are met. The preset conditions are used to indicate that the urea injection system can work normally when there is urea in the pipeline of the urea injection system. The first control module is used to control the urea injection system to perform incomplete post-suction and venting according to the preset conditions. The second control module is used to control the urea injection system to perform front-mounted back-suction venting in response to vehicle startup. The third control module is used to control the urea injection system to perform complete back-suction and emptying if the preset conditions are not met. The second control module is also used for: In response to vehicle startup, the temperature of the exhaust gas entering the selective catalytic reduction system is obtained and compared with a temperature threshold. Based on the exhaust gas temperature being greater than the temperature threshold, the urea injection system is controlled to perform incomplete pre-sumption and back-suction. Based on the exhaust gas temperature being less than or equal to the temperature threshold, the urea injection system is controlled to perform complete pre-sucking and venting. The time for complete post-inverted suction and emptying is t, the time for incomplete post-inverted suction and emptying is t1, the time for incomplete pre-inverted suction and emptying is t2, and the time for complete pre-inverted suction and emptying is t3, where t = t1 + t3, and t > t1 + t2. Among them, pre-sucking and emptying refers to the back-sucking and emptying performed before the urea injection system completes normal injection work; Incomplete pre-vacuuming refers to the back-vacuuming performed before the urea injection system completes normal injection. After incomplete pre-vacuuming, some urea remains in the pipeline of the urea injection system. Complete pre-suction evacuation means that the urea injection system performs the evacuation before it completes normal injection, and after the complete pre-suction evacuation, the urea in the pipeline of the urea injection system is completely emptied. Incomplete post-back suction evacuation refers to the back suction evacuation being carried out after the urea injection system has completed its normal injection operation. After incomplete post-back suction evacuation, some urea remains in the pipes of the urea injection system. Complete post-reverse suction evacuation refers to the process of performing reverse suction evacuation after the urea injection system has completed its normal injection operation. After performing complete post-reverse suction evacuation, the urea in the pipeline of the urea injection system is completely emptied.

6. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the urea injection system backflow method according to any one of claims 1 to 4.

7. A computer storage medium, characterized in that, The computer storage medium stores computer-readable instructions that, when read by one or more processors, cause one or more processors to perform the steps of the urea injection system backflow method as described in any one of claims 1 to 4.

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