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

Abstract

The present invention provides a protection method, device, diesel vehicle, and storage medium for a urea pump pressure sensor, belonging to the field of exhaust gas aftertreatment technology. A urea pump is used to spray urea solution from a urea tank into an exhaust gas aftertreatment device. The urea pump includes a liquid inlet branch, an air inlet branch, and a nozzle with a nozzle directed toward the exhaust gas aftertreatment device. The liquid inlet branch includes an inlet pipe and a pressure sensor connected to the inlet pipe, and the air inlet branch includes an inlet pipe and a drain valve for controlling the opening and closing of the inlet pipe. The method includes: determining whether there is a risk of freezing of urea solution in the inlet pipe; when there is a risk of freezing, controlling the drain valve to open for a preset period of time, thereby transferring air from the inlet pipe to the inlet pipe to form a cavity. The present invention transfers air from the inlet pipe to the liquid inlet pipe, where the air forms a cavity in the inlet pipe for ice expansion, thereby improving the safety and reliability of the pressure sensor when the urea solution freezes.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust gas post-processing, 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 main harmful substances in diesel vehicle exhaust are nitrogen oxides and particulate matter. While particulate emissions can be reduced through internal engine technology, nitrogen oxides are the primary component of exhaust. Urea decomposes into ammonia at high temperatures, which reacts with nitrogen oxides under the action of a catalyst to produce harmless nitrogen and water. Therefore, existing technologies have proposed using a urea pump to inject urea solution into an exhaust aftertreatment device for exhaust gas post-treatment. To meet pressure monitoring requirements, the urea pump is equipped with a pressure sensor to monitor the urea solution pressure.

[0003] The urea solution in the urea pump freezes at low temperatures. Once frozen, the urea solution expands, causing the pressure sensor to crack or drift in measured values. To address this technical issue, existing technologies have proposed installing an expansion plug inside the pressure sensor. This plug deforms and absorbs the expansion as the urea freezes. However, due to the limited deformation of the material, it cannot fully absorb the volume expansion caused by freezing, and thus cannot completely prevent the pressure sensor from cracking or measuring failures when the urea solution freezes. Furthermore, installing an expansion plug in the pressure sensor is limited by hardware layout space and manufacturing processes, making it less practical.

[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 freezes 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 preventing the pressure sensor from freezing and cracking when the urea solution freezes by installing an expansion plug in the pressure sensor, which cannot completely prevent the pressure sensor from freezing and cracking and has low applicability.

[0006] On one hand, to solve the above technical problems, the present invention provides a method for protecting a urea pump pressure sensor. The urea pump is used to spray urea solution in a urea tank to an 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 method includes:

[0007] Determining whether there is a risk of urea solution in the liquid inlet pipeline freezing;

[0008] When there is a risk of icing, the drain valve is controlled to open for a preset time, so that the air in the air intake line is transported to the liquid intake line to form a cavity.

[0009] In one possible implementation, determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline includes:

[0010] 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;

[0011] determining a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump;

[0012] 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.

[0013] 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:

[0014] Determining whether the ambient temperature and the power-on temperature are less than a preset temperature;

[0015] 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;

[0016] 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.

[0017] In one possible implementation, the state of the urea pump includes a pre-filling 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:

[0018] When the state of the urea pump is a 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 an icing risk;

[0019] When the state of the urea pump is the injection state, determining whether the injection amount is less than a preset injection amount and whether a duration during which the injection amount is less than the preset injection amount is greater than a duration threshold; when the injection amount is less than the preset injection amount and a 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;

[0020] When the state of the urea pump is an emptying state, the flow freezing risk assessment result is that there is no freezing risk;

[0021] 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.

[0022] In a possible implementation, determining whether there is a risk of icing of the urea solution in the liquid inlet pipeline further includes:

[0023] receiving a message sent by the controller, and determining whether there is a need to unfreeze based on the message;

[0024] When the thawing requirement 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;

[0025] 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.

[0026] In a possible implementation, the preset duration is:

[0027] T=C*V / Q

[0028] Where, 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.

[0029] In a possible implementation, before controlling the drain valve to open for a preset time, the method further includes:

[0030] obtaining the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline;

[0031] determining whether the air inlet pressure is greater than the liquid inlet pressure;

[0032] Then, controlling the emptying valve to be opened for a preset time period includes:

[0033] When the air intake pressure is greater than the liquid intake pressure, the drain valve is controlled to open for a preset time period.

[0034] On the other hand, the present invention also provides a protection device for a urea pump pressure sensor. The urea pump is used to spray urea solution in a urea tank to an 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:

[0035] an icing risk judgment unit, configured to judge whether there is an icing risk for the urea solution in the liquid inlet pipeline;

[0036] 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 inlet line to the liquid inlet line to form a cavity.

[0037] On the other hand, the present invention also provides a diesel vehicle, comprising a memory and a processor, wherein:

[0038] The memory is used to store programs;

[0039] The processor is coupled to the memory and is configured to execute the program stored in the memory to implement the steps of the method for protecting the urea pump pressure sensor described in any one of the possible implementations above.

[0040] On the other hand, the present invention also provides a computer-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method for protecting the urea pump pressure sensor described in any one of the possible implementations described above are implemented.

[0041] The beneficial effects of the present invention are as follows: the protection method for the urea pump pressure sensor provided by the present invention controls the opening time of the drain valve to a preset time when there is a risk of freezing of the urea solution in the liquid inlet line, and transports the air in the air intake line to the liquid inlet line, where the air forms a cavity in the liquid inlet line for expansion due to freezing. Since the absorption and expansion capacity of air is much higher than that of the expansion plug, the expansion space in the present invention is larger than that of the method of providing an expansion plug in the pressure sensor, 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 makes it 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

[0042] 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.

[0043] Figure 1 A schematic structural diagram of an embodiment of a urea pump provided by the present invention;

[0044] Figure 2 A schematic flow chart of an embodiment of a method for protecting a urea pump pressure sensor provided by the present invention;

[0045] Figure 3 For the present invention Figure 2 A schematic flow chart of an embodiment of S201;

[0046] Figure 4 For the present invention Figure 3 A schematic flow chart of an embodiment of S301;

[0047] Figure 5 For the present invention Figure 2 Another embodiment of the flow chart of S202;

[0048] Figure 6 A schematic structural diagram of an embodiment of a protection device for a urea pump pressure sensor provided by the present invention;

[0049] Figure 7 This is a schematic structural diagram of an embodiment of a diesel vehicle provided by the present invention. DETAILED DESCRIPTION

[0050] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0051] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present invention illustrate operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps that have no logical contextual relationship can be reversed in order or implemented simultaneously. In addition, those skilled in the art, guided by the content of the present invention, can add one or more other operations to the flowcharts or remove one or more operations from the flowcharts. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0052] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0053] 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.

[0054] 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 intake 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 intake branch 12 includes an air intake pipeline 121 and an emptying valve 122 for controlling the on-off of the air intake pipeline 121.

[0055] 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, Figure 1 As shown, the urea pump 10 further includes a supply pump 14 provided on the liquid inlet pipe 111 , and the supply pump 14 is used to deliver the urea solution in the urea tank 20 to the liquid inlet pipe 111 .

[0056] Furthermore, during the operation of the urea pump 10, it is necessary to introduce the 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 after-treatment device 30 through the 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 1As shown, the urea pump 10 further includes a one-way valve 15 provided 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 .

[0057] 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 in the figure, the protection method of the urea pump pressure sensor includes:

[0058] S201, determining whether there is a risk of urea solution in the liquid inlet pipeline freezing;

[0059] 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.

[0060] Among them, 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: when the air in the intake pipe enters the liquid inlet pipe, a cavity will be formed 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.

[0061] Compared to the prior art, the protection method for a urea pump pressure sensor provided in an embodiment of the present invention controls the opening time of the drain valve to a preset length of time when the urea solution in the liquid inlet line is at risk of freezing, thereby transferring air from the air intake line to the liquid inlet line. The air forms a cavity in the liquid inlet line for expansion upon freezing. Because the absorptive expansion capacity of air is much higher than that of an expansion plug, the expansion space provided by the present invention is larger than that provided by an expansion plug in the pressure sensor, further preventing the pressure sensor from freezing and cracking, thereby improving the safety and reliability of the pressure sensor when the urea solution freezes. Furthermore, the size of the cavity can be controlled based on the opening time of the drain valve, providing greater controllability. 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.

[0062] Since 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 urea solution has a large flow rate 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:

[0063] 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;

[0064] S302: Determine a flow freezing risk assessment result of the urea solution in the liquid inlet pipeline based on the state of the urea pump;

[0065] 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.

[0066] The embodiment of the present invention determines the temperature freezing risk assessment results and the flow freezing risk assessment results, and judges whether the urea solution in the liquid inlet pipeline has a freezing risk from the two dimensions of temperature and fluidity, thereby improving the accuracy of the freezing risk judgment and ensuring the safety of the pressure sensor.

[0067] In a specific embodiment of the present invention, Figure 4 As shown, step S301 includes:

[0068] S401, determining whether the ambient temperature and the power-on temperature are less than a preset temperature;

[0069] 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;

[0070] 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.

[0071] The preset temperature is the freezing point of the urea solution, specifically, the preset temperature is -11°C.

[0072] The urea pump includes normal state and fault state. The normal state includes pre-filling state, injection state and emptying state.

[0073] It should be noted that when the urea solution in the liquid inlet pipe is not flowing and the freezing temperature is met, the urea solution is at risk of freezing. Otherwise, there is no freezing risk. Therefore, it is necessary to judge the fluidity of the urea solution under different conditions. Specifically, step S302 is as follows:

[0074] 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 an freezing risk.

[0075] When the pre-injection 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.

[0076] When the urea pump is in the injection state, it is determined whether the injection amount is less than the preset injection amount, and whether the duration for which the injection amount is less than the preset injection amount is greater than a duration threshold; when the injection amount is less than the preset injection amount, and the duration for 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;

[0077] The preset injection volume refers to the injection volume at which the urea solution is considered non-flowing. In other words, when the injection volume is too small and remains in this state for an extended period, the flow is considered non-flowing. If the injection volume is greater than or equal to the preset injection volume, or if the duration of the injection volume being less than the preset injection volume is less than or equal to the event threshold, the flow icing risk assessment indicates that there is no icing wind direction.

[0078] When the urea pump is in the emptying state, the flow freezing risk assessment result is that there is no freezing risk.

[0079] When the urea pump is in the emptying state, the emptying valve opens, and the air in the intake circuit flows into the liquid inlet pipe, discharging all the urea solution in the liquid inlet pipe 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.

[0080] 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.

[0081] When a fault event occurs, normal purging is still possible. At this time, the air in the intake pipe will purge the liquid inlet pipe, increasing 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.

[0082] The embodiment of the present invention determines the flow icing risk assessment results under various states of the urea pump respectively, thereby improving the accuracy and comprehensiveness of the flow icing risk assessment results.

[0083] It should be understood that: the ambient temperature and power-on temperature in step S301 need to be acquired by temperature sensors. 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:

[0084] S501: Receive a message from a controller and determine whether there is a need to unfreeze based on the message;

[0085] 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;

[0086] 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.

[0087] The embodiment of the present invention provides 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 possible to accurately determine whether there is a freezing risk in the urea solution, thereby improving the diversity and redundancy of the freezing risk determination methods.

[0088] Specifically, when there is a request to open the cooling water valve in the message, it is considered that there is a thawing demand.

[0089] One reason the cooling water valve opens is that the urea solution can freeze when the ambient temperature is very low. To prevent this, the urea solution needs to be heated with engine cooling water (80°C-90°C). In other words, a request to open the cooling water valve indicates that there is a risk of freezing in the urea solution.

[0090] 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:

[0091] T=C*V / Q

[0092] Where, 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.

[0093] The embodiment of the present invention sets a preset time based on the flow space, volume expansion coefficient and volume flow rate to ensure that a cavity sufficient to absorb the freezing and expansion of urea is created in the liquid inlet pipeline, ensuring that the pressure sensor will not freeze and crack.

[0094] It should be noted that: in actual application, the opening time of the drain valve does not need to be 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.

[0095] 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 intake 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 further included:

[0096] Obtain the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline;

[0097] determining whether the air inlet pressure is greater than the liquid inlet pressure;

[0098] The drain valve is controlled to open for a preset time, including:

[0099] When the air inlet pressure is greater than the liquid inlet pressure, the drain valve is controlled to open for a preset time.

[0100] The embodiment of the present invention is arranged to first 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 pipe can successfully enter the liquid intake pipe to form a cavity, thereby avoiding ineffective opening of the drain valve.

[0101] The inlet pressure can be Figure 1 The pressure is obtained by detection of the pressure sensor arranged in the liquid inlet pipeline.

[0102] 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 .

[0103] 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, 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:

[0104] The freezing risk judgment unit 601 is used to judge whether there is a freezing risk for the urea solution in the liquid inlet pipeline;

[0105] 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.

[0106] 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 embodiment of the protection method for the above 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 embodiment of the protection method for the above urea pump pressure sensor, and will not be described one by one here.

[0107] 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 of the components of the diesel vehicle 700 are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.

[0108] In some embodiments, the processor 701 is an electronic control unit (ECU) in the diesel vehicle 700 , and is configured to execute program codes stored in the memory 702 or process data, such as the protection method for the urea pump pressure sensor of the present invention.

[0109] In some embodiments, the memory 702 may be an internal storage unit of the diesel vehicle 700 , such as a hard disk or memory of the diesel vehicle 700 .

[0110] 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.

[0111] In some embodiments, display 703 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 703 is used to display information about diesel vehicle 700 and to present a visual user interface. Components 701-703 of diesel vehicle 700 communicate with each other via a system bus.

[0112] 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:

[0113] Determine whether there is a risk of urea solution in the liquid inlet pipeline freezing;

[0114] When there is a risk of icing, the drain valve is controlled to open for a preset time, and the air in the air inlet line is transported to the liquid inlet line. The air forms a cavity in the liquid inlet line for ice expansion.

[0115] It should be understood that, when executing the protection program for the urea pump pressure sensor in the memory 702 , the processor 701 may implement other functions in addition to the above functions. For details, please refer to the description of the corresponding method embodiment above.

[0116] 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.

[0117] Those skilled in the art will appreciate that all or part of the process flow of the above-described method embodiment can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0118] 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 herein to illustrate the principles and implementation methods 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 ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for protecting a urea pump pressure sensor, characterized in that: A urea pump is used to spray urea solution in a urea tank to an 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 an inlet pipe and a pressure sensor connected to the inlet pipe. The air inlet branch includes an inlet pipe and a drain valve for controlling the on / off of the inlet pipe. The method includes: determining whether there is a freezing risk for the urea solution in the liquid inlet pipeline, including determining that there is a freezing risk for the urea solution in the liquid inlet pipeline when both a temperature freezing risk assessment result and a flow freezing risk assessment result indicate that there is a freezing risk; When the urea pump is in the injection state, it is determined whether the injection amount is less than a preset injection amount, and whether the duration during which the injection amount is less than the preset injection amount is greater than a duration threshold; when the injection amount is less than the preset injection amount, and the 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 indicates that there is an icing risk; When there is a risk of icing, the drain valve is controlled to open for a preset time, so that the air in the air intake line is transported to the liquid intake line to form a cavity.

2. The protection method for a urea pump pressure sensor according to claim 1, characterized in that: The determining whether there is a risk of freezing of the urea solution in the liquid inlet pipeline further 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 the urea tank is powered on; A flow freezing risk assessment result of the urea solution in the liquid inlet line is determined based on the state of the urea pump.

3. The protection method for a 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 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.

4. The protection method for a urea pump pressure sensor according to claim 2, characterized in that: The state of the urea pump further includes a pre-filling state, an emptying state, and a 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 a 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 an icing risk; When the state of the urea pump is an emptying 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 for a urea pump pressure sensor according to claim 2, characterized in that: The determining whether there is a risk of freezing of the urea solution in the liquid inlet pipeline further includes: receiving a message sent by the controller, and determining whether there is a need to unfreeze based on the message; When the thawing requirement 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 method for protecting a urea pump pressure sensor according to claim 1, characterized in that: The preset duration is: T=C*V / Q Where, 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 for a 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: obtaining the air intake pressure of the air intake pipeline and the liquid intake pressure of the liquid intake pipeline; determining whether the air inlet pressure is greater than the liquid inlet pressure; Then, controlling the emptying valve to be opened 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: A method for protecting a urea pump pressure sensor according to any one of claims 1 to 7, wherein the urea pump is used to spray urea solution in a urea tank into an exhaust gas after-treatment device, the urea pump comprising 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 comprising a liquid inlet pipeline and a pressure sensor connected to the liquid inlet pipeline, the air inlet branch comprising an air inlet pipeline and a drain valve for controlling the on / off of the air inlet pipeline; the device comprising: an icing risk judgment unit, configured 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 inlet line to the liquid inlet 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 configured to execute the program stored in the memory to implement the steps of the urea pump pressure sensor protection method 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 instruction, and when the program or instruction is executed by the processor, the steps of the method for protecting the urea pump pressure sensor according to any one of claims 1 to 7 are implemented.

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