Protection method and device for urea pump pressure sensor, diesel vehicle and storage medium

Abstract

The invention provides a protection method and device for a urea pump pressure sensor, a diesel vehicle and a storage medium, and belongs to the technical field of tail gas after-treatment, a urea pump is used for spraying a urea solution in a urea tank to a tail gas after-treatment device, and the urea pump comprises a liquid inlet branch, a gas inlet branch and a nozzle with a nozzle facing the tail gas after-treatment device; the liquid inlet branch comprises a liquid inlet pipeline and a pressure sensor communicated with the liquid inlet pipeline, and the air inlet branch comprises an air inlet pipeline and an emptying valve for controlling the on-off of the air inlet pipeline; the method comprises the following steps: judging whether a urea solution in a liquid inlet pipeline has an icing risk or not; and when the icing risk exists, the emptying valve is controlled to be opened for a preset duration, and air in the air inlet pipeline is conveyed to the liquid inlet pipeline to form a cavity. According to the invention, air in the air inlet pipeline is conveyed to the liquid inlet pipeline, and the air forms a cavity in the liquid inlet pipeline for icing expansion, so that the safety and reliability of the pressure sensor when the urea solution is iced are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust gas post-treatment, and in particular to a protection method and device for a urea pump pressure sensor, a diesel vehicle and a storage medium. Background Art

[0002] The harmful substances in diesel vehicle exhaust are mainly nitrogen oxides and particulates. The particulate emissions can be reduced by technical means inside the engine. The exhaust is mainly nitrogen oxides. Since urea decomposes into ammonia at high temperature, it will react with nitrogen oxides under the action of catalysts to generate harmless nitrogen and water. Therefore, the prior art proposes to post-treat the exhaust by injecting urea solution into the exhaust post-treatment device through a urea pump. And in order to meet the pressure monitoring requirements, a pressure sensor for monitoring the pressure of the urea solution is provided in the urea pump.

[0003] The urea solution in the urea pump will freeze at low temperatures. After freezing, the volume of the urea solution expands, which can cause the pressure sensor to freeze and crack or the measured value to drift. To solve this technical problem, the prior art proposes to install an expansion plug inside the pressure sensor, which can deform and absorb the expansion when the urea freezes and expands. However, due to the limited deformation of the material, it cannot completely absorb the volume of the frozen expansion, and it is still impossible to completely avoid the pressure sensor from freezing and cracking or measurement failure when the urea solution freezes. In addition, installing an expansion plug in the pressure sensor is not very applicable due to the hardware layout space and manufacturing process.

[0004] Therefore, there is an urgent need to provide a protection method, device, diesel vehicle and storage medium for a urea pump pressure sensor to ensure the safety and reliability of the pressure sensor when the urea solution is frozen and to improve the applicability of this method. Summary of the invention

[0005] In view of this, it is necessary to provide a protection method, device, diesel vehicle and storage medium for a urea pump pressure sensor to solve the technical problems in the prior art of installing an expansion plug in the pressure sensor to prevent the pressure sensor from freezing and cracking when the urea solution freezes, such as failure to completely prevent the pressure sensor from freezing and cracking and low applicability.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a protection method for a urea pump pressure sensor, wherein the urea pump is used to spray a urea solution in a urea tank to an exhaust gas after-treatment device, the urea pump comprises a liquid inlet branch, an air inlet branch and a nozzle with a nozzle facing the exhaust gas after-treatment device, the liquid inlet branch comprises a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline, the air inlet branch comprises an air inlet pipeline and a drain valve for controlling the on-off of the air inlet pipeline; the method comprises: Determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline; When there is a risk of icing, the drain valve is controlled to open for a preset time to transport the air in the air intake line to the liquid intake line to form a cavity.

[0007] In a possible implementation, determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline includes: Determining a temperature freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the ambient temperature and the power-on temperature of the urea tank when it is powered on; Determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; When both the temperature freezing risk assessment result and the flow freezing risk assessment result indicate that there is freezing risk, it is determined that the urea solution in the liquid inlet pipeline has freezing risk.

[0008] In a possible implementation, determining a temperature freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the ambient temperature and the power-on temperature of the urea tank when the urea tank is powered on includes: Determining whether the ambient temperature and the power-on temperature are less than a preset temperature; When the ambient temperature or the power-on temperature is lower than a preset temperature, the temperature freezing risk assessment result is that there is a freezing risk; When the ambient temperature and the power-on temperature are greater than or equal to a preset temperature, the temperature freezing risk assessment result is that there is no freezing risk.

[0009] In a possible implementation, the state of the urea pump includes a pre-injection state, an injection state, an emptying state, and a fault state; and determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump includes: When the state of the urea pump is the pre-injection state, determining whether the pre-injection is completed, and when the pre-injection is completed, the flow freezing risk assessment result is that there is a freezing risk; When the state of the urea pump is the injection state, it is determined whether the injection amount is less than the preset injection amount, and whether the time duration during which the injection amount is less than the preset injection amount is greater than a time threshold; when the injection amount is less than the preset injection amount, and the time duration during which the injection amount is less than the preset injection amount is greater than a time threshold, the flow icing risk assessment result is that there is an icing risk; When the state of the urea pump is an empty state, the flow freezing risk assessment result is that there is no freezing risk; When the state of the urea pump is a fault state, it is determined whether a fault event of the fault state is a purge failure event. When the fault event of the fault state is a purge failure event, the flow icing risk assessment result is that there is an icing risk.

[0010] In a possible implementation, the determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline further includes: receiving a message sent by the controller, and determining whether there is a thawing requirement based on the message; When the thawing demand exists, determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; When the flow freezing risk assessment result indicates that there is freezing risk, it is determined that the urea solution in the liquid inlet pipeline has freezing risk.

[0011] In a possible implementation, the preset duration is: T=C*V / Q In the formula, T The preset duration; C is the volume expansion coefficient of urea solution when it freezes; V It is the circulation space for urea solution; Q is the volume flow rate of air.

[0012] In a possible implementation manner, before controlling the drain valve to open for a preset time, the method further includes: Acquiring the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline; Determining whether the air intake pressure is greater than the liquid intake pressure; Then, controlling the emptying valve to open for a preset time period includes: When the air intake pressure is greater than the liquid intake pressure, the drain valve is controlled to open for a preset time period.

[0013] On the other hand, the present invention further provides a protection device for a urea pump pressure sensor, wherein the urea pump is used to spray a urea solution in a urea tank to an exhaust gas aftertreatment device, wherein the urea pump comprises a liquid inlet branch, an air inlet branch, and a nozzle with a nozzle facing the exhaust gas aftertreatment device, wherein the liquid inlet branch comprises a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline, and wherein the air inlet branch comprises an air inlet pipeline and an exhaust valve for controlling the on-off of the air inlet pipeline; wherein the device comprises: an icing risk judgment unit, used to judge whether there is an icing risk for the urea solution in the liquid inlet pipeline; The cavity forming unit is used to control the emptying valve to open for a preset time when there is a risk of icing, so as to transport the air in the air intake line to the liquid intake line to form a cavity.

[0014] On the other hand, the present invention also provides a diesel vehicle, comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the method for protecting the urea pump pressure sensor described in any one of the possible implementations above.

[0015] On the other hand, the present invention also provides a computer-readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps in the method for protecting the urea pump pressure sensor described in any one of the possible implementations mentioned above are implemented.

[0016] The beneficial effects of the present invention are as follows: the protection method of the urea pump pressure sensor provided by the present invention controls the preset opening time of the drain valve when there is a risk of freezing of the urea solution in the liquid inlet pipeline, and transports the air in the air intake pipeline to the liquid inlet pipeline, where the air forms a cavity in the liquid inlet pipeline for expansion due to freezing. Since the absorption and expansion capacity of air is much higher than the absorption and expansion capacity of the expansion plug, compared with the method of setting an expansion plug in the pressure sensor, the expansion space in the present invention is larger, which can further avoid the problem of ice expansion and cracking of the pressure sensor, and improve the safety and reliability of the pressure sensor when the urea solution freezes. In addition, the size of the cavity can be controlled according to the opening time of the drain valve, which is more controllable. Furthermore, the present invention is not affected by the hardware layout space and manufacturing process, and has good adaptability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic structural diagram of an embodiment of a urea pump provided by the present invention; Figure 2 A schematic flow chart of an embodiment of a method for protecting a urea pump pressure sensor provided by the present invention; Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of S201; Figure 4 For the present invention Figure 3 A schematic flow chart of an embodiment of S301; Figure 5 For the present invention Figure 2 Another embodiment of S202 is a flowchart of FIG. Figure 6 A schematic structural diagram of an embodiment of a protection device for a urea pump pressure sensor provided by the present invention; Figure 7 This is a schematic structural diagram of an embodiment of a diesel vehicle provided by the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] It should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowchart can be implemented out of order, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present invention, can add one or more other operations to the flowchart, and can also remove one or more operations from the flowchart. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0021] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] The present invention provides a protection method and device for a urea pump pressure sensor, a diesel vehicle and a storage medium, which are described below respectively.

[0023] Before showing the specific implementation, the urea pump is introduced first. Figure 1 As shown, the urea pump 10 is used to spray the urea solution in the urea tank 20 to the exhaust gas after-treatment device 30. The urea pump 10 includes a liquid inlet branch 11, an air inlet branch 12 and a nozzle 13 with a nozzle facing the exhaust gas after-treatment device 30. The liquid inlet branch 11 includes a liquid inlet pipeline 111 and a pressure sensor 112 connected to the liquid inlet pipeline 111. The air inlet branch 12 includes an air inlet pipeline 121 and an exhaust valve 122 for controlling the on-off of the air inlet pipeline 121.

[0024] In order to make the urea solution in the urea tank 20 have enough power to fill the liquid inlet pipe 111 and spray it to the exhaust gas post-treatment device 30, as shown in FIG. Figure 1 As shown, the urea pump 10 further includes a supply pump 14 disposed on the liquid inlet pipeline 111 , and the supply pump 14 is used to transport the urea solution in the urea tank 20 to the liquid inlet pipeline 111 .

[0025] Furthermore, during the operation of the urea pump 10, it is necessary to introduce air in the air intake branch 12 into the liquid intake branch 11, and purge the urea solution in the liquid intake branch 11 into the exhaust gas post-treatment device 30 through air. However, it is necessary to ensure that the urea solution in the liquid intake branch 11 cannot enter the air intake branch 12. Therefore, Figure 1 As shown, the urea pump 10 further includes a one-way valve 15 disposed between the air intake branch 12 and the liquid intake branch 11 . The one-way valve 15 ensures that the medium can only flow from the air intake branch 12 to the liquid intake branch 11 , but cannot flow from the liquid intake branch 11 to the air intake branch 12 .

[0026] Based on the above urea pump 10, an embodiment of the present invention provides a method for protecting a urea pump pressure sensor, such as Figure 2 As shown, the protection method of the urea pump pressure sensor includes: S201, determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline; S202: When there is a risk of icing, control the drain valve to open for a preset time to transport the air in the air intake line to the liquid intake line to form a cavity.

[0027] The principle of preventing the pressure sensor from freezing and cracking by transporting the air in the intake pipe to the liquid inlet pipe is that the air in the intake pipe enters the liquid inlet pipe, forming a cavity in the liquid inlet pipe filled with urea solution. This cavity can absorb the expansion of ice and provide space for the expansion of ice, thereby preventing the expansion of ice from cracking the pressure sensor.

[0028] Compared with the prior art, the protection method of the urea pump pressure sensor provided in the embodiment of the present invention controls the emptying valve to open for a preset time when there is a risk of freezing of the urea solution in the liquid inlet pipeline, and transports the air in the air intake pipeline to the liquid inlet pipeline, where the air forms a cavity in the liquid inlet pipeline for expansion due to freezing. Since the absorption and expansion capacity of air is much higher than that of the expansion plug, compared with the method of setting an expansion plug in the pressure sensor, the expansion space in the present invention is larger, which can further avoid the problem of ice expansion and cracking of the pressure sensor, and improve the safety and reliability of the pressure sensor when the urea solution freezes. In addition, the size of the cavity can be controlled according to the opening time of the emptying valve, which is more controllable. Furthermore, the embodiment of the present invention is not affected by the hardware layout space and manufacturing process, and has good adaptability and low cost.

[0029] Whether the urea solution freezes depends not only on the temperature but also on the fluidity of the urea solution. For example, the urea solution will freeze when the temperature is less than -11°C, but it will not freeze if the flow rate of the urea solution is large when the temperature is less than -11°C. Therefore, in order to improve the accuracy of the judgment of the freezing risk in step S201, in some embodiments of the present invention, Figure 3 As shown, step S201 includes: S301, determining a temperature freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the ambient temperature and the power-on temperature of the urea tank when it is powered on; S302, determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; S303: When both the temperature freezing risk assessment result and the flow freezing risk assessment result indicate that there is freezing risk, it is determined that the urea solution in the liquid inlet pipeline has freezing risk.

[0030] The embodiment of the present invention determines the temperature freezing risk assessment result and the flow freezing risk assessment result, and judges whether the urea solution in the liquid inlet pipeline has the freezing risk from the two dimensions of temperature and fluidity, thereby improving the accuracy of the judgment of the freezing risk and ensuring the safety of the pressure sensor.

[0031] In a specific embodiment of the present invention, Figure 4 As shown, step S301 includes: S401, determining whether the ambient temperature and the power-on temperature are less than a preset temperature; S402: When the ambient temperature or the power-on temperature is lower than the preset temperature, the temperature freezing risk assessment result is that there is a freezing risk; S403: When the ambient temperature and the power-on temperature are greater than or equal to the preset temperature, the temperature freezing risk assessment result is that there is no freezing risk.

[0032] The preset temperature is the freezing point of the urea solution, specifically, the preset temperature is -11°C.

[0033] The urea pump includes a normal state and a fault state. The normal state includes a pre-filling state, an injection state and an emptying state.

[0034] It should be noted that: when the urea solution in the liquid inlet pipeline does not flow, the urea solution will have a risk of freezing only when the freezing temperature is met, otherwise there is no risk of freezing. Therefore, it is necessary to judge the fluidity of the urea solution under different conditions. Specifically, step S302 is as follows: When the state of the urea pump is the pre-injection state, it is determined whether the pre-injection is completed. When the pre-injection is completed, the flow freezing risk assessment result is that there is a freezing risk.

[0035] When the pre-filling is not completed, the flow rate of the urea solution in the liquid inlet pipeline is large, that is, the fluidity is large and there is no risk of freezing.

[0036] When the state of the urea pump is the injection state, it is determined whether the injection amount is less than the preset injection amount, and whether the time duration during which the injection amount is less than the preset injection amount is greater than the time threshold; when the injection amount is less than the preset injection amount, and the time duration during which the injection amount is less than the preset injection amount is greater than the time threshold, the flow icing risk assessment result is that there is an icing risk; The preset injection amount refers to the injection amount of the urea solution that can be regarded as not flowing. In other words, when the injection amount in the injection state is too small and remains in this state of too small injection amount for a long time, this state is regarded as a non-flowing state. If the injection amount is greater than or equal to the preset injection amount or the duration of the injection amount being less than the preset injection amount is less than or equal to the event threshold, the flow icing risk assessment result is determined to be that there is no icing wind direction.

[0037] When the urea pump is in the emptying state, the flow freezing risk assessment result is that there is no freezing risk.

[0038] When the urea pump is in the emptying state, the emptying valve opens, and the air in the intake circuit rushes into the liquid inlet pipeline, and all the urea solution in the liquid inlet pipeline is discharged to the exhaust gas after-treatment device. At this time, the urea solution in the liquid inlet circuit has strong fluidity and there is no risk of freezing.

[0039] When the state of the urea pump is a fault state, it is determined whether the fault event of the fault state is a purge failure event. When the fault event of the fault state is a purge failure event, the flow icing risk assessment result is that there is an icing risk.

[0040] When a fault event occurs, normal purging is still possible. At this time, the air in the air intake pipe will purge the liquid inlet pipe to increase the fluidity of the urea solution. Therefore, the flow icing risk assessment result is that there is an icing risk only when the fault event of the fault state is an event that cannot be purged. Otherwise, the flow icing risk assessment result is that there is no icing risk.

[0041] The embodiments of the present invention respectively determine the flow icing risk assessment results under various states of the urea pump, thereby improving the accuracy and comprehensiveness of the flow icing risk assessment results.

[0042] It should be understood that: the ambient temperature and the power-on temperature in step S301 need to be acquired by a temperature sensor, and when the temperature sensor fails or is not set, the temperature risk assessment result cannot be determined, and thus the opening time of the drain valve cannot be accurately determined. In order to solve this technical problem, in some embodiments of the present invention, such as Figure 5 , step S201 further includes: S501, receiving a message sent by a controller, and determining whether there is a thawing requirement based on the message; S502: when there is a thawing demand, determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; S503: When the flow freezing risk assessment result indicates that there is a freezing risk, it is determined that the urea solution in the liquid inlet pipeline has a freezing risk.

[0043] The embodiment of the present invention sets a process for determining whether there is a thawing demand based on a message instead of a temperature freezing risk assessment result. When the ambient temperature and the power-on temperature are unknown, it is also possible to accurately determine whether the urea solution has a freezing risk, thereby improving the diversity and redundancy of the freezing risk determination methods.

[0044] Specifically, when there is a request to open the cooling water valve in the message, it is considered that there is a thawing demand.

[0045] One of the reasons for opening the cooling water valve is that when the ambient temperature is very low, the urea solution will freeze. To prevent this from happening, the engine cooling water (80°C - 90°C) is needed to heat the urea solution. In other words, the request to open the cooling water valve indicates that the urea solution is at risk of freezing.

[0046] In order to improve the rationality of the drain valve opening time, in a specific embodiment of the present invention, the preset time length is: T=C*V / Q In the formula, T The preset duration; C is the volume expansion coefficient of urea solution when it freezes; V It is the circulation space for urea solution; Q is the volume flow rate of air.

[0047] The embodiment of the present invention sets a preset time based on the flow space, the volume expansion coefficient and the volume flow rate to ensure that a cavity sufficient to absorb the freezing and expansion of urea is created in the liquid inlet pipeline to ensure that the pressure sensor will not freeze and crack.

[0048] It should be noted that: in actual applications, the opening time of the drain valve only needs to be no less than the preset time, and it can be opened for a slightly longer period of time to ensure that the cavity is sufficient to absorb the expansion of ice.

[0049] Since the liquid inlet pipeline needs to build up pressure before injection so that the pressure of the urea solution reaches the working pressure, in order to prevent the air in the air inlet pipeline from being unable to be effectively transported to the liquid inlet circuit, in some embodiments of the present invention, before controlling the drain valve to open for a preset time in step S202, the following steps are also included: Obtaining the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline; Determining whether the air intake pressure is greater than the liquid intake pressure; The drain valve is controlled to open for a preset time, including: When the air inlet pressure is greater than the liquid inlet pressure, the drain valve is controlled to open for a preset time.

[0050] The embodiment of the present invention is arranged to compare the intake pressure and the liquid intake pressure before opening the drain valve, to ensure that after the drain valve is opened, the air in the intake pipeline can successfully enter the liquid intake pipeline to form a cavity, thereby avoiding ineffective opening of the drain valve.

[0051] The inlet pressure can be Figure 1 The pressure is obtained by detection by a pressure sensor arranged in the liquid inlet pipeline.

[0052] In order to detect the intake pressure, Figure 1 As shown, the urea pump 10 further includes a pressure sensor 112 connected to the intake pipe 121 to detect the pressure of the intake pipe 121 .

[0053] In order to better implement the protection method of the urea pump pressure sensor in the embodiment of the present invention, based on the protection method of the urea pump pressure sensor, correspondingly, the embodiment of the present invention further provides a protection device for the urea pump pressure sensor, the urea pump is used to spray the urea solution in the urea tank to the exhaust gas after-treatment device, the urea pump includes a liquid inlet branch, an air intake branch and a nozzle with a nozzle facing the exhaust gas after-treatment device, the liquid inlet branch includes a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline, the air intake branch includes an air intake pipeline and an emptying valve for controlling the on-off of the air intake pipeline; Figure 6 As shown, the protection device 600 of the urea pump pressure sensor includes: The freezing risk judgment unit 601 is used to judge whether there is a freezing risk of the urea solution in the liquid inlet pipeline; The cavity forming unit 602 is used to control the emptying valve to open for a preset time when there is a risk of icing, so as to transport the air in the air inlet line to the liquid inlet line to form a cavity.

[0054] It should be noted that the protection device 600 for the urea pump pressure sensor provided in the above embodiment can implement the technical solution described in the above embodiment of the protection method for the urea pump pressure sensor. The specific implementation principles or specific implementation details of the above modules or units can be found in the corresponding contents in the above embodiment of the protection method for the urea pump pressure sensor, which will not be described one by one here.

[0055] like Figure 7 As shown, the present invention also provides a diesel vehicle 700. The diesel vehicle 700 includes a processor 701, a memory 702 and a display 703. Figure 7Only some components of the diesel vehicle 700 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0056] In some embodiments, the processor 701 is an electronic control unit (ECU) in the diesel vehicle 700 , and is used to run program codes or process data stored in the memory 702 , such as the protection method of the urea pump pressure sensor in the present invention.

[0057] In some embodiments, the memory 702 may be an internal storage unit of the diesel vehicle 700 , such as a hard disk or a memory of the diesel vehicle 700 .

[0058] Furthermore, the memory 702 may include both an internal storage unit of the diesel vehicle 700 and an external storage device. The memory 702 is used to store application software installed in the diesel vehicle 700 and various data.

[0059] In some embodiments, the display 703 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 703 is used to display information of the diesel vehicle 700 and to display a visual user interface. The components 701-703 of the diesel vehicle 700 communicate with each other via a system bus.

[0060] In some embodiments of the present invention, when the processor 701 executes the protection program of the urea pump pressure sensor in the memory 702, the following steps may be implemented: Determine whether there is a risk of icing of the urea solution in the liquid inlet pipeline; When there is a risk of icing, the drain valve is controlled to open for a preset time to transport the air in the air intake line to the liquid intake line. The air forms a cavity in the liquid intake line for ice expansion.

[0061] It should be understood that: when the processor 701 executes the protection program of the urea pump pressure sensor in the memory 702 , in addition to the above functions, other functions may also be implemented, and the details may refer to the description of the above corresponding method embodiments.

[0062] Accordingly, an embodiment of the present invention further provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions of the protection method of the urea pump pressure sensor provided in the above-mentioned method embodiments can be implemented.

[0063] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0064] The above is a detailed introduction to the protection method, device, diesel vehicle and storage medium of a urea pump pressure sensor provided by the present invention. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for protecting a urea pump pressure sensor, characterized in that: The urea pump is used to spray the urea solution in the urea tank to the exhaust gas after-treatment device, the urea pump comprises a liquid inlet branch, an air inlet branch and a nozzle with a nozzle facing the exhaust gas after-treatment device, the liquid inlet branch comprises a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline, the air inlet branch comprises an air inlet pipeline and a drain valve for controlling the opening and closing of the air inlet pipeline; the method comprises: Determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline; When there is a risk of icing, the drain valve is controlled to open for a preset time to transport the air in the air intake line to the liquid intake line to form a cavity.

2. The protection method of the urea pump pressure sensor according to claim 1, characterized in that: The determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline includes: Determining a temperature freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the ambient temperature and the power-on temperature of the urea tank when it is powered on; Determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; When both the temperature freezing risk assessment result and the flow freezing risk assessment result indicate that there is freezing risk, it is determined that the urea solution in the liquid inlet pipeline has freezing risk.

3. The protection method of the urea pump pressure sensor according to claim 2, characterized in that: Determining a temperature freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the ambient temperature and the power-on temperature of the urea tank when the urea tank is powered on, including: Determining whether the ambient temperature and the power-on temperature are less than a preset temperature; When the ambient temperature or the power-on temperature is lower than a preset temperature, the temperature freezing risk assessment result is that there is a freezing risk; When the ambient temperature and the power-on temperature are greater than or equal to a preset temperature, the temperature freezing risk assessment result is that there is no freezing risk.

4. The protection method of the urea pump pressure sensor according to claim 2, characterized in that: The states of the urea pump include pre-filling state, injection state, emptying state and fault state; Determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump includes: When the state of the urea pump is the pre-injection state, determining whether the pre-injection is completed, and when the pre-injection is completed, the flow freezing risk assessment result is that there is a freezing risk; When the state of the urea pump is the injection state, it is determined whether the injection amount is less than the preset injection amount, and whether the time duration during which the injection amount is less than the preset injection amount is greater than a time threshold; when the injection amount is less than the preset injection amount, and the time duration during which the injection amount is less than the preset injection amount is greater than a time threshold, the flow icing risk assessment result is that there is an icing risk; When the state of the urea pump is an empty state, the flow freezing risk assessment result is that there is no freezing risk; When the state of the urea pump is a fault state, it is determined whether a fault event of the fault state is a purge failure event. When the fault event of the fault state is a purge failure event, the flow icing risk assessment result is that there is an icing risk.

5. The protection method of the urea pump pressure sensor according to claim 2, characterized in that: The determining whether the urea solution in the liquid inlet pipeline has a risk of freezing also includes: receiving a message sent by the controller, and determining whether there is a thawing requirement based on the message; When the thawing demand exists, determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump; When the flow freezing risk assessment result indicates that there is freezing risk, it is determined that the urea solution in the liquid inlet pipeline has freezing risk.

6. The protection method of the urea pump pressure sensor according to claim 1, characterized in that: The preset duration is: T=C*V / Q In the formula, T The preset duration; C is the volume expansion coefficient of urea solution when it freezes; V It is the circulation space for urea solution; Q is the volume flow rate of air.

7. The protection method of the urea pump pressure sensor according to claim 1, characterized in that: Before controlling the drain valve to open for a preset time, the method further includes: Acquiring the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline; Determining whether the air intake pressure is greater than the liquid intake pressure; Then, controlling the emptying valve to open for a preset time period includes: When the air intake pressure is greater than the liquid intake pressure, the drain valve is controlled to open for a preset time period.

8. A protection device for a urea pump pressure sensor, characterized in that: The urea pump is used to spray the urea solution in the urea tank to the exhaust gas after-treatment device. The urea pump includes a liquid inlet branch, an air inlet branch and a nozzle with a nozzle facing the exhaust gas after-treatment device. The liquid inlet branch includes a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline. The air inlet branch includes an air inlet pipeline and a drain valve for controlling the on-off of the air inlet pipeline. The device includes: an icing risk judgment unit, used to judge whether there is an icing risk for the urea solution in the liquid inlet pipeline; The cavity forming unit is used to control the emptying valve to open for a preset time when there is a risk of icing, so as to transport the air in the air intake line to the liquid intake line to form a cavity.

9. A diesel vehicle, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the protection method of the urea pump pressure sensor according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program or an instruction, and when the program or the instruction is executed by the processor, the steps in the method for protecting the urea pump pressure sensor according to any one of claims 1 to 7 are implemented.

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