Pump-back control method, system and equipment of urea pump and readable storage medium

Abstract

The invention discloses a pumpback control method, system and equipment of a urea pump and a readable storage medium, and relates to the technical field of automobile motors. The pumpback control method specifically comprises the steps that the real-time cooling and pressure maintaining duration and the real-time injection amount are determined based on the real-time exhaust temperature and the real-time exhaust flow; target shutdown duration is determined based on the real-time cooling and pressure maintaining duration and the real-time injection amount, and target pumpback parameters are determined according to the target shutdown duration; and the urea pump is controlled to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, pumpback control over the urea pump is conducted based on the target pumpback parameters. According to the invention, the suction of suspended matters in the exhaust system during pump-back can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of automotive motors, and particularly relates to a method, a system, a device, and a readable storage medium for back-drawing control of a urea pump. Background Art

[0002] With the wide application of the diesel engine aftertreatment SCR (Silicon Controlled Rectifier) system after the National V stage, the demand for precise control of diesel engine exhaust pollutant NOx is increasing day by day, and the urea nozzle structure has become a key component to achieve this goal. Currently, 32.5% concentration of on-vehicle urea solution (GB29518-2013) is widely used as a reducing agent in the diesel engine aftertreatment SCR system; however, the urea solution will start to form urea crystals in the temperature range of 190°C to 350°C, will polymerize into cyanuric acid and its derivatives in the range of 190°C to 325°C, and will polymerize into melamine in the range of 325°C to 350°C. These urea crystals usually appear in the form of white crystals. Since the engine exhaust system belongs to an open-loop structure directly leading to the atmosphere, its composition and physical properties are difficult to meet the micron-level cleanliness requirements, so the urea crystal substances are likely to cause blockage or jamming of the nozzle flow channel.

[0003] The prior art usually directly performs back-drawing after the urea pump stops to avoid blockage or jamming of the nozzle flow channel, but this will cause the suspension in the exhaust system to be inhaled during back-drawing. Therefore, how to avoid inhaling the suspension in the exhaust system during back-drawing is an urgent problem to be solved currently. Summary of the Invention

[0004] The present application provides a method, a system, a device, and a readable storage medium for back-drawing control of a urea pump, which can avoid inhaling the suspension in the exhaust system during back-drawing.

[0005] In a first aspect, an embodiment of the present application provides a method for back-drawing control of a urea pump, and the method for back-drawing control of the urea pump includes:

[0006] Determining a real-time cooling and pressure-holding duration and a real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate;

[0007] Determining a target shutdown duration based on the real-time cooling and pressure-holding duration and the real-time injection amount, and determining a target back-drawing parameter according to the target shutdown duration;

[0008] Controlling the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, performing back-drawing control of the urea pump based on the target back-drawing parameter.

[0009] Combined with the first aspect, in an implementation manner, the determining a real-time cooling and pressure-holding duration and a real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate includes:

[0010] Determine the real-time cooling and pressure maintaining duration based on the relationship between the real-time exhaust temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range;

[0011] Determine the real-time injection amount corresponding to the real-time cooling and pressure maintaining duration based on the mapping relationship between the preset cooling and heat preservation duration and the injection amount.

[0012] Combined with the first aspect, in an implementation manner, the flow rate range includes a first flow rate range and a second flow rate range, and the determining the real-time cooling and pressure maintaining duration based on the relationship between the real-time exhaust temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range includes:

[0013] When it is detected that the real-time exhaust temperature is within the first temperature range and the real-time exhaust gas flow rate is within the first flow rate range, control the cooling and pressure maintaining duration to be the first cooling and pressure maintaining duration;

[0014] When it is detected that the real-time exhaust temperature is within the first temperature range and the real-time exhaust gas flow rate is within the second flow rate range, control the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0015] Wherein, the lower limit value of the first flow rate range is greater than the upper limit value of the second flow rate range, and the first pressure reduction and heat preservation duration is greater than the second pressure reduction and heat preservation duration.

[0016] Combined with the first aspect, in an implementation manner, the method further includes:

[0017] When it is detected that the real-time exhaust temperature is not within the first temperature range and the real-time exhaust temperature is within a preset second temperature range, control the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0018] When it is detected that the real-time exhaust temperature is not within the first temperature range and the real-time exhaust temperature is within a preset third temperature range, control the cooling and pressure maintaining duration to be the third cooling and pressure maintaining duration;

[0019] When it is detected that the real-time exhaust temperature is not within the first temperature range and the real-time exhaust temperature is within a preset fourth temperature range, control the cooling and pressure maintaining duration to be the fourth cooling and pressure maintaining duration;

[0020] Wherein, the lower limit value of the first temperature range is greater than the upper limit value of the second temperature range, the lower limit value of the second temperature range is greater than the upper limit value of the third temperature range, the lower limit value of the third temperature range is greater than the upper limit value of the fourth temperature range, and the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, and the fourth cooling and pressure maintaining duration are sorted from largest to smallest as: the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, the fourth cooling and pressure maintaining duration.

[0021] In connection with the first aspect, in one embodiment, before the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate, the method further includes:

[0022] Obtaining an engine speed signal and an engine ignition signal;

[0023] When it is detected that the engine speed signal is less than a preset speed threshold or the engine ignition signal is a preset target value, the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate is executed, and the preset target value is used to represent that the engine is not in an ignition state;

[0024] When it is detected that the engine speed signal is not less than the preset speed threshold and the engine ignition signal is not the preset target value, the steps of obtaining the engine speed signal and the engine ignition signal are re-executed.

[0025] In connection with the first aspect, in one embodiment, after the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate, the method further includes:

[0026] Performing a cooling and pressure maintaining process on the urea pump based on the real-time cooling and pressure maintaining duration;

[0027] After the cooling and pressure maintaining is completed, performing a crystallization prevention protective injection process on the urea pump based on the real-time injection amount.

[0028] In connection with the first aspect, in one embodiment, the determining the target backflow parameter according to the target shutdown duration includes:

[0029] Determining a target backflow parameter corresponding to the target shutdown duration based on a preset mapping relationship between the shutdown duration and the backflow parameter, where the target backflow parameter includes a target backflow duration, a target backflow speed, a target nozzle opening duty cycle, and a target backflow frequency.

[0030] In a second aspect, an embodiment of the present application provides a backflow control system for a urea pump, and the backflow control system for the urea pump includes:

[0031] A first processing module, which is used to determine a real-time cooling and pressure maintaining duration and a real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate;

[0032] A second processing module, which is used to determine a target shutdown duration based on the real-time cooling and pressure maintaining duration and the real-time injection amount, and determine a target backflow parameter according to the target shutdown duration;

[0033] A third processing module, which is used to control the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, perform backflow control on the urea pump based on the target backflow parameter.

[0034] In a third aspect, an embodiment of the present application provides a back - pumping control device for a urea pump. The back - pumping control device for the urea pump includes a processor, a memory, and a back - pumping control program for the urea pump that is stored on the memory and executable by the processor. When the back - pumping control program for the urea pump is executed by the processor, the steps of the back - pumping control method for the urea pump as described in any one of the foregoing are implemented.

[0035] In a fourth aspect, an embodiment of the present application provides a computer - readable storage medium. A back - pumping control program for a urea pump is stored on the computer - readable storage medium. When the back - pumping control program for the urea pump is executed by a processor, the steps of the back - pumping control method for the urea pump as described in any one of the foregoing are implemented.

[0036] The beneficial effects brought by the technical solutions provided in the embodiments of the present application include:

[0037] By determining the real - time cooling and pressure - maintaining duration and the real - time injection amount based on the real - time exhaust temperature and the real - time exhaust flow rate to avoid the formation of crystallization; determining the target shutdown duration based on the real - time cooling and pressure - maintaining duration and the real - time injection amount, and determining the target back - pumping parameter according to the target shutdown duration; then controlling the urea pump to enter the shutdown state and making the shutdown duration of the urea pump reach the target shutdown duration to allow the suspended matter to settle. At this time, based on the target back - pumping parameter, the back - pumping control of the urea pump is carried out, which can prevent the urea pump from sucking in suspended particulate matter during back - pumping, and then avoid the suspended particulate matter from being sucked into the nozzle flow channel during back - pumping. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic flowchart of an embodiment of the back - pumping control method for the urea pump of the present application;

[0039] Figure 2 It is a schematic logic diagram of an embodiment of the back - pumping control method for the urea pump of the present application;

[0040] Figure 3 For the present application Figure 1 It is a schematic flowchart of the refinement of step S10 in the present application;

[0041] Figure 4 It is a schematic architecture diagram of an embodiment of the back - pumping control system for the urea pump of the present application;

[0042] Figure 5 It is a schematic hardware structure diagram of the back - pumping control device for the urea pump involved in the solution of the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solution in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of this application.

[0044] To make the purpose, technical solution and advantages of this application clearer, the following will further describe the embodiments of this application in detail in conjunction with the accompanying drawings.

[0045] In a first aspect, an embodiment of this application provides a method for controlling the back-drawing of a urea pump.

[0046] In one embodiment, referring to Figure 1 , Figure 1 is a schematic flowchart of an embodiment of the method for controlling the back-drawing of the urea pump of this application. As Figure 1 shown, the method for controlling the back-drawing of the urea pump includes:

[0047] Step S10: Determine the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate.

[0048] Exemplarily, in the embodiments of this application, the real-time exhaust gas temperature refers to the temperature when the gas in the exhaust system flows through the exhaust pipe. The level of the exhaust gas temperature directly reflects the heat load and energy state of the exhaust gas; the real-time exhaust gas flow rate refers to the amount of flowing gas in the exhaust system per unit time, which reflects the flow velocity and flow rate of the gas; the real-time cooling and pressure-holding duration refers to the duration corresponding to reducing the exhaust gas temperature by injecting a coolant and maintaining a certain working pressure in the exhaust system. The cooling and pressure-holding duration needs to be dynamically adjusted according to the changes in the real-time exhaust gas temperature and the real-time exhaust gas flow rate to ensure the stable operation of the system within a reasonable temperature and pressure range; the real-time injection amount refers to the amount of cooling medium injected into the exhaust flow to prevent urea crystallization.

[0049] Specifically, the real-time exhaust gas temperature is a key monitoring index during the cooling process. When the exhaust gas temperature exceeds the set threshold, the system starts the cooling program to avoid urea solution crystallization caused by too high temperature; at the same time, the real-time exhaust gas flow rate data reflects the flow state of the urea solution in the urea pump. Too low a flow rate indicates that the urea solution may face the risk of crystallization; therefore, the real-time cooling and pressure-holding duration can be dynamically determined through the relationship between the real-time exhaust gas temperature and the preset temperature range and the relationship between the real-time exhaust gas flow rate and the preset flow rate range; after determining the real-time cooling and pressure-holding duration, the system can determine the real-time injection amount corresponding to the real-time cooling and pressure-holding duration according to the mapping relationship between the preset cooling and pressure-holding duration and the injection amount to ensure the continuity of the injection system and the fluidity of the solution.

[0050] Step S20: Determine a target shutdown duration based on the real-time cooling and pressure maintaining duration and the real-time injection volume, and determine a target backflow parameter according to the target shutdown duration.

[0051] Exemplarily, in the embodiment of the present application, the target shutdown duration corresponding to the real-time cooling and pressure maintaining duration and the real-time injection volume can be determined according to the preset mapping relationship between the cooling and pressure maintaining duration, the injection volume and the shutdown duration; for example, as shown in Figure 2 The shutdown duration corresponding to the first pressure reduction and heat preservation duration and the first injection volume is the first shutdown duration, the shutdown duration corresponding to the second pressure reduction and heat preservation duration and the second injection volume is the first shutdown duration, the shutdown duration corresponding to the third pressure reduction and heat preservation duration and the third injection volume is the second shutdown duration, and the shutdown duration corresponding to the fourth pressure reduction and heat preservation duration and the fourth injection volume is the second shutdown duration; assuming that the real-time cooling and pressure maintaining duration is the second cooling and pressure maintaining duration and the real-time injection volume is the second injection volume, then the target shutdown duration corresponding to the two is the first shutdown duration; after determining the target shutdown duration, the target backflow parameter corresponding to the target shutdown duration can be determined according to the mapping relationship between the shutdown duration and the backflow parameter, so as to perform backflow control on the urea pump based on the target backflow parameter subsequently.

[0052] Step S30: Control the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, perform backflow control on the urea pump based on the target backflow parameter.

[0053] Exemplarily, in the embodiment of the present application, before controlling the urea pump to perform backflow, it is first necessary to ensure that the urea pump is in a shutdown state, that is, control the urea pump to enter the stop program and keep it from performing any emission or conveying operations; then monitor the shutdown duration of the urea pump until it reaches the predetermined target shutdown duration, so that the suspended particles in the exhaust system can settle down, avoiding the suspended particles being sucked into the nozzle flow channel during backflow; after the shutdown duration of the urea pump reaches the target shutdown duration, the urea pump can be controlled to enter the backflow program, that is, the system can start the backflow control of the urea pump according to the target backflow parameter to ensure the backflow efficiency, thereby avoiding blockage or jamming of the nozzle flow channel.

[0054] The present application determines the real-time cooling and pressure maintaining duration and the real-time injection volume based on the real-time exhaust temperature and the real-time exhaust flow rate to avoid the formation of crystallization; determines the target shutdown duration based on the real-time cooling and pressure maintaining duration and the real-time injection volume, and determines the target backflow parameter according to the target shutdown duration; then controls the urea pump to enter the shutdown state and makes the shutdown duration of the urea pump reach the target shutdown duration to make the suspended matter settle down. At this time, perform backflow control on the urea pump based on the target backflow parameter, which can prevent the urea pump from sucking in suspended particles during backflow, and then avoid the suspended particles being sucked into the nozzle flow channel during backflow.

[0055] Further, in one embodiment, referring to Figure 3 as shown, the determination of the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate includes:

[0056] Step S101: Determine the real-time cooling and pressure maintaining duration based on the relationship between the real-time exhaust gas temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range;

[0057] Step S102: Determine the real-time injection amount corresponding to the real-time cooling and pressure maintaining duration based on the mapping relationship between the preset cooling and pressure maintaining duration and the injection amount.

[0058] Exemplarily, in the embodiments of the present application, the specific values of the preset first temperature range and the preset flow rate range can be determined according to actual requirements and are not limited herein; the mapping relationship between the preset cooling and pressure maintaining duration and the injection amount can be obtained through experiments and is not limited herein;

[0059] Specifically, the system can adjust the duration of cooling and pressure maintaining according to the relationship between the exhaust gas temperature and the first temperature range to ensure that the exhaust gas temperature is maintained within a safe range, thereby avoiding urea crystallization; at the same time, the change in the real-time exhaust gas flow rate will also affect the cooling and pressure maintaining effect. Therefore, the duration of cooling and pressure maintaining can also be adjusted according to the relationship between the exhaust gas flow rate and the flow rate range to adapt to the change in the air flow and ensure effective cooling and pressure maintaining; it can be understood that by the relationship between the real-time exhaust gas temperature and the preset first temperature range, and in combination with the relationship between the real-time exhaust gas flow rate and the preset flow rate range, the system can dynamically evaluate the heat load and flow state of the exhaust system, and then can determine the real-time cooling and pressure maintaining duration according to the real-time exhaust gas temperature and the real-time flow rate; and then, according to the mapping relationship between the preset cooling and pressure maintaining duration and the injection amount, further calculate the real-time injection amount corresponding to the real-time cooling and pressure maintaining duration to ensure that the amount of the injected cooling medium is just right.

[0060] Further, in one embodiment, the flow rate range includes a first flow rate range and a second flow rate range. The determination of the real-time cooling and pressure maintaining duration based on the relationship between the real-time exhaust gas temperature and the preset first temperature range and the relationship between the real-time exhaust gas flow rate and the preset flow rate range includes:

[0061] When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the first flow rate range, control the cooling and pressure maintaining duration to be the first cooling and pressure maintaining duration;

[0062] When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the second flow rate range, control the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0063] Among them, the lower limit value of the first flow rate range is greater than the upper limit value of the second flow rate range, and the first pressure reduction and heat preservation duration is greater than the second pressure reduction and heat preservation duration.

[0064] Exemplarily, in the embodiments of the present application, the flow rate range includes a first flow rate range and a second flow rate range. Among them, the first flow rate range and the second flow rate range can be determined according to actual needs, as long as the lower limit value of the first flow rate range is greater than the upper limit value of the second flow rate range, and no further limitation is made here; the first pressure reduction and heat preservation duration and the second pressure reduction and heat preservation duration can also be determined according to actual needs, as long as the first pressure reduction and heat preservation duration is greater than the second pressure reduction and heat preservation duration, and no further limitation is made here.

[0065] Specifically, when the system detects that the exhaust gas temperature is within a preset first temperature range, it indicates that the exhaust gas temperature has reached a relatively high level. At this time, measures for cooling and maintaining pressure are required to prevent urea crystallization; however, since temperature only reflects the thermal state of the gas, the exhaust gas flow rate can further affect the heat transfer and cooling efficiency. Therefore, it is also necessary to determine the cooling and pressure maintaining duration in combination with the magnitude of the exhaust gas flow rate; referring to Figure 2 As shown, if it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the first flow rate range, it indicates that both the exhaust gas temperature and the exhaust gas flow rate are at a relatively high level, and it means that the heat distribution in the gas may be uneven and the pressure of the gas may fluctuate greatly. Therefore, a longer cooling and pressure maintaining time is required to help balance the heat distribution in the system and slowly control the pressure change, which can be achieved by controlling the cooling and pressure maintaining duration to be the first cooling and pressure maintaining duration.

[0066] It should be understood that, referring to Figure 2 As shown, if it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the second flow rate range, it indicates that the exhaust gas temperature is relatively high but the exhaust gas flow rate is lower than the lower limit value of the first flow rate range (i.e., the exhaust gas flow rate is small). Therefore, compared with the situation where both the exhaust gas temperature and the exhaust gas flow rate are relatively high, the cooling and pressure maintaining duration at this time should be less than the first cooling and pressure maintaining duration. Then, it can be achieved by controlling the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration. In the embodiments of the present application, the cooling and pressure maintaining duration is adjusted by double monitoring of temperature and flow rate, so that the system can flexibly optimize the cooling and pressure maintaining process under different working conditions to effectively prevent urea crystallization.

[0067] Furthermore, in one embodiment, the method further includes:

[0068] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset second temperature range, controlling the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0069] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset third temperature range, control the cooling and pressure maintaining duration to be the third cooling and pressure maintaining duration;

[0070] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset fourth temperature range, control the cooling and pressure maintaining duration to be the fourth cooling and pressure maintaining duration;

[0071] Wherein, the lower limit value of the first temperature range is greater than the upper limit value of the second temperature range, the lower limit value of the second temperature range is greater than the upper limit value of the third temperature range, the lower limit value of the third temperature range is greater than the upper limit value of the fourth temperature range, and the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, and the fourth cooling and pressure maintaining duration are sorted from largest to smallest as: the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, the fourth cooling and pressure maintaining duration.

[0072] Exemplarily, in the embodiment of the present application, the preset second temperature range, the preset third temperature range, and the preset fourth temperature range can be determined according to actual needs, as long as the lower limit value of the first temperature range is greater than the upper limit value of the second temperature range, the lower limit value of the second temperature range is greater than the upper limit value of the third temperature range, and the lower limit value of the third temperature range is greater than the upper limit value of the fourth temperature range, which is not limited herein; the specific values of the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, and the fourth cooling and pressure maintaining duration can be determined according to actual requirements, as long as they are sorted from largest to smallest as: the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, the fourth cooling and pressure maintaining duration, which is not limited herein.

[0073] It should be noted that when it is detected that the real-time exhaust gas temperature is not within the first temperature range, it indicates that the exhaust gas temperature is at a relatively low level at this time. Since in the low-temperature case, the change in flow has less influence on the heat conduction and cooling process of the system; therefore, the cooling and pressure maintaining duration under low-temperature conditions is more dependent on temperature rather than flow to control, thereby avoiding excessive duration consumption or premature equipment intervention.

[0074] Specifically, refer to Figure 2As shown, when it is detected that the real-time exhaust gas temperature is not within the first temperature range and is within the second temperature range, it indicates that the exhaust gas temperature at this time is lower than the lower limit value of the first temperature range, further indicating that the degree of uneven heat distribution in the gas is weaker than the situation corresponding to the exhaust gas temperature within the first temperature range. Then, the cooling and pressure maintaining duration at this time should be less than the first cooling and pressure maintaining duration. Therefore, it can be achieved by controlling the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration; when it is detected that the real-time exhaust gas temperature is not within the first temperature range and is within the third temperature range, it indicates that the exhaust gas temperature at this time is lower than the lower limit value of the second temperature range, further indicating that the degree of uneven heat distribution in the gas is weaker than the situation corresponding to the exhaust gas temperature within the second temperature range. Then, the cooling and pressure maintaining duration at this time should be less than the second cooling and pressure maintaining duration. Therefore, it can be achieved by controlling the cooling and pressure maintaining duration to be the third cooling and pressure maintaining duration.

[0075] It can be understood that, referring to Figure 2 As shown, when it is detected that the real-time exhaust gas temperature is not within the first temperature range and is within the preset fourth temperature range, it indicates that the exhaust gas temperature at this time is lower than the lower limit value of the third temperature range, further indicating that the degree of uneven heat distribution in the gas is weaker than the situation corresponding to the exhaust gas temperature within the third temperature range. Then, the cooling and pressure maintaining duration at this time should be less than the third cooling and pressure maintaining duration. Therefore, it can be achieved by controlling the cooling and pressure maintaining duration to be the fourth cooling and pressure maintaining duration.

[0076] Further, in one embodiment, before the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate, it further includes:

[0077] Obtain the engine speed signal and the engine ignition signal;

[0078] When it is detected that the engine speed signal is less than the preset speed threshold or the engine ignition signal is the preset target value, then execute the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate, and the preset target value is used to represent that the engine is not in the ignition state;

[0079] When it is detected that the engine speed signal is not less than the preset speed threshold and the engine ignition signal is not the preset target value, then re-execute the step of obtaining the engine speed signal and the engine ignition signal.

[0080] Exemplarily, in the embodiments of the present application, the engine speed signal represents the rotational speed of the engine crankshaft, which reflects the operating speed of the engine. The engine speed signal is usually collected by sensors such as a crankshaft position sensor or a camshaft position sensor. Among them, the specific value of the preset speed threshold can be determined according to actual needs and is not limited herein. For example, the preset speed threshold can preferably be taken as 0; the engine ignition signal is used to indicate whether the current engine is in the ignition state, and it can be collected by an ignition sensor. Among them, the preset target value is used to represent that the engine is not in the ignition state, and it can be determined according to actual needs. For example, the preset target value can preferably be taken as key off; the engine speed signal and the engine ignition signal work together to ensure that the engine obtains a suitable control strategy under different working conditions.

[0081] Specifically, after obtaining the engine speed signal and the ignition signal, if it is detected that the engine speed signal is less than the preset speed threshold or the engine ignition signal is the preset target value, it indicates that the engine is in a non-operating state, and then enter the step of determining the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust temperature and the exhaust gas flow rate to ensure that the system makes appropriate adjustments according to the actual working conditions; on the contrary, if it is detected that the engine speed signal is not less than the preset speed threshold and the ignition signal is not the preset target value, it indicates that the engine is in a normal operating state, and the control system re-obtains the engine speed signal and the ignition signal until the threshold conditions are met.

[0082] Further, in one embodiment, after the step of determining the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust gas flow rate, it further includes:

[0083] Perform cooling and pressure-holding treatment on the urea pump based on the real-time cooling and pressure-holding duration;

[0084] After the cooling and pressure-holding is completed, perform anti-crystallization protective injection treatment on the urea pump based on the real-time injection amount.

[0085] Exemplarily, in the embodiments of the present application, after the urea pump is controlled to enter the cooling and pressure-holding program, the cooling program is first started according to the temperatures of the pump body and the urea solution monitored in real time, and the temperature of the urea pump is gradually reduced to ensure that the urea solution is within an appropriate temperature range, thereby preventing the formation of urea crystallization due to excessive temperature; the key objective during the cooling process is to avoid the crystallization of the urea solution by gradually reducing the temperature while ensuring that the pump body and the system are not damaged by overheating; during this process, the pressure of the pump body is also monitored and adjusted in real time to maintain it within a safe range, thereby preventing pressure fluctuations or pump body damage caused by sharp temperature changes, and ensuring the smooth progress of the cooling process, that is, avoiding the risk of crystallization and maintaining the normal operation of the system; after the cooling and pressure-holding is completed, the urea pump is controlled to enter the anti-crystallization protective injection program. At this time, the system will start the anti-crystallization protective injection treatment according to the real-time injection volume, and the solution can be ensured to maintain fluidity by periodically injecting the urea solution into the injection system, thereby preventing the formation of crystallization and ensuring the normal operation of the urea injection system. Through the orderly treatment of cooling, pressure-holding, and anti-crystallization injection, the reliability and long-term stability of the urea pump in extreme environments are ensured, thereby preventing urea crystallization and preventing blockage or jamming problems of the urea pump.

[0086] Further, in one embodiment, the determining the target backflow parameters according to the target shutdown duration includes:

[0087] Determining the target backflow parameters corresponding to the target shutdown duration based on the mapping relationship between the preset shutdown duration and the backflow parameters, where the target backflow parameters include the target backflow duration, the target backflow speed, the target nozzle opening duty ratio, and the target backflow frequency.

[0088] Exemplarily, in the embodiments of the present application, the mapping relationship between the preset shutdown duration and the backflow parameters can be obtained through experiments, which is not limited herein; the target backflow parameters include the target backflow duration, the target backflow speed, the target nozzle opening duty ratio, and the target backflow frequency. Among them, the target backflow duration refers to the duration of the backflow operation of the system after the urea injection ends; the target backflow speed refers to the speed at which the urea pump operates during the backflow process; the target nozzle opening duty ratio refers to the working cycle of the nozzle during the backflow process, that is, the proportion of the duration when the nozzle is in the open state in the entire cycle; the target backflow frequency refers to the operation frequency during the backflow process, that is, the number of backflow operations within a certain period of time; these parameters work together to ensure that the urea injection system maintains a good working state during the backflow process, avoiding urea crystallization and nozzle blockage.

[0089] Specifically, referring to Figure 2As shown, it is assumed that the first shutdown duration corresponds to the first back-pumping duration, the first back-pumping speed, the first nozzle opening duty cycle, and the first back-pumping frequency, and the first shutdown duration also corresponds to the second back-pumping duration, the second back-pumping speed, the first nozzle opening duty cycle, and the first back-pumping frequency; the second shutdown duration corresponds to the third back-pumping duration, the third back-pumping speed, the second nozzle opening duty cycle, and the second back-pumping frequency, and the second shutdown duration also corresponds to the fourth back-pumping duration, the fourth back-pumping speed, the second nozzle opening duty cycle, and the second back-pumping frequency; then when the target shutdown duration is the second shutdown duration, the target back-pumping duration can be the third back-pumping duration or the fourth back-pumping duration, the target back-pumping speed can be the third back-pumping speed or the fourth back-pumping speed, the target nozzle opening duty cycle is the second nozzle opening duty cycle, and the target back-pumping frequency is the second back-pumping frequency.

[0090] In a second aspect, an embodiment of the present application further provides a back-pumping control system for a urea pump.

[0091] In one embodiment, referring to Figure 4 , Figure 4 is a schematic diagram of the functional modules of an embodiment of the back-pumping control system of the urea pump of the present application. As Figure 4 shown, the back-pumping control system of the urea pump includes:

[0092] A first processing module, which is used to determine the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate;

[0093] A second processing module, which is used to determine the target shutdown duration based on the real-time cooling and pressure-holding duration and the real-time injection amount, and determine the target back-pumping parameters according to the target shutdown duration;

[0094] A third processing module, which is used to control the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, perform back-pumping control of the urea pump based on the target back-pumping parameters.

[0095] Further, in one embodiment, the first processing module is specifically used for:

[0096] Determine the real-time cooling and pressure-holding duration based on the relationship between the real-time exhaust gas temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range;

[0097] Determine the real-time injection amount corresponding to the real-time cooling and pressure-holding duration based on the mapping relationship between the preset cooling and heat-preserving duration and the injection amount.

[0098] Further, in one embodiment, the flow rate range includes a first flow rate range and a second flow rate range, and the first processing module is specifically further used for:

[0099] When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the first flow rate range, control the cooling and pressure maintaining duration to be the first cooling and pressure maintaining duration;

[0100] When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the second flow rate range, control the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0101] Wherein, the lower limit value of the first flow rate range is greater than the upper limit value of the second flow rate range, and the first pressure reduction and heat preservation duration is greater than the second pressure reduction and heat preservation duration.

[0102] Further, in an embodiment, the first processing module is further specifically configured to:

[0103] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset second temperature range, control the cooling and pressure maintaining duration to be the second cooling and pressure maintaining duration;

[0104] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset third temperature range, control the cooling and pressure maintaining duration to be the third cooling and pressure maintaining duration;

[0105] When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset fourth temperature range, control the cooling and pressure maintaining duration to be the fourth cooling and pressure maintaining duration;

[0106] Wherein, the lower limit value of the first temperature range is greater than the upper limit value of the second temperature range, the lower limit value of the second temperature range is greater than the upper limit value of the third temperature range, the lower limit value of the third temperature range is greater than the upper limit value of the fourth temperature range, and the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, and the fourth cooling and pressure maintaining duration are sorted from largest to smallest as: the second cooling and pressure maintaining duration, the third cooling and pressure maintaining duration, the fourth cooling and pressure maintaining duration.

[0107] Further, in an embodiment, the first processing module is further specifically configured to:

[0108] Obtain the engine speed signal and the engine ignition signal;

[0109] When it is detected that the engine speed signal is less than the preset speed threshold or the engine ignition signal is the preset target value, then execute the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate, and the preset target value is used to represent that the engine is not in the ignition state;

[0110] When it is detected that the engine speed signal is not less than the preset speed threshold and the engine ignition signal is not the preset target value, then re-execute the step of obtaining the engine speed signal and the engine ignition signal.

[0111] Further, in one embodiment, the first processing module is specifically further configured to:

[0112] Perform temperature reduction and pressure maintenance processing on the urea pump based on the real-time temperature reduction and pressure maintenance duration;

[0113] After the temperature reduction and pressure maintenance ends, perform anti-crystallization protective injection processing on the urea pump based on the real-time injection volume.

[0114] Further, in one embodiment, the second processing module is specifically configured to:

[0115] Determine a target backflush parameter corresponding to the target shutdown duration based on the mapping relationship between the preset shutdown duration and the backflush parameter, where the target backflush parameter includes a target backflush duration, a target backflush speed, a target nozzle opening duty ratio, and a target backflush frequency.

[0116] In this application, the real-time temperature reduction and pressure maintenance duration and the real-time injection volume are determined based on the real-time exhaust temperature and the real-time exhaust gas flow rate to avoid the formation of crystallization; the target shutdown duration is determined based on the real-time temperature reduction and pressure maintenance duration and the real-time injection volume, and the target backflush parameter is determined according to the target shutdown duration; then the urea pump is controlled to enter the shutdown state, and the shutdown duration of the urea pump reaches the target shutdown duration to make the suspended matter precipitate. At this time, the backflush control of the urea pump is performed based on the target backflush parameter, which can prevent the urea pump from sucking in suspended particulate matter during backflush, and then avoid the suspended particulate matter from being sucked into the nozzle flow channel during backflush.

[0117] Among them, the function implementation of each module in the above urea pump backflush control system corresponds to each step in the above urea pump backflush control method embodiment, and its function and implementation process will not be elaborated here one by one.

[0118] In a third aspect, an embodiment of the present application provides a urea pump backflush control device. The urea pump backflush control device can be a device with data processing functions such as a personal computer (PC), a laptop computer, a server, etc.

[0119] Refer to Figure 5 , Figure 5 This is a schematic diagram of the hardware structure of the urea pump backflush control device involved in the embodiment solution of the present application. In the embodiment of the present application, the urea pump backflush control device may include a processor, a memory, a communication interface, and a communication bus.

[0120] Among them, the communication bus can be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0121] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces, etc., which are used to implement the interconnection of components inside the back-pumping control device of the urea pump, and interfaces for implementing the interconnection between the back-pumping control device of the urea pump and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0122] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical memory, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0123] The processor can be a general-purpose processor, which can call the back-pumping control program of the urea pump stored in the memory and execute the back-pumping control method provided by the embodiments of the present application. For example, the general-purpose processor can be a central processing unit (CPU). Among them, the method executed when the back-pumping control program of the urea pump is called can refer to the various embodiments of the back-pumping control method of the urea pump in the present application, which will not be elaborated here.

[0124] Those skilled in the art can understand that Figure 5 the hardware structure shown in

[0125] does not constitute a limitation to the present application, and may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0126] The readable storage medium of the present application stores a back-pumping control program of the urea pump, and when the back-pumping control program of the urea pump is executed by a processor, the steps of the back-pumping control method as described above are implemented.

[0127] Among them, the method implemented when the back-pumping control program of the urea pump is executed can refer to the various embodiments of the back-pumping control method of the urea pump in the present application, which will not be elaborated here.

[0128] In the description of the specification, claims and the above-mentioned drawings of this application, the terms "comprising", "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products or devices. Descriptions such as "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second" and "third" are different types.

[0129] In the description of the embodiments of this application, words such as "exemplary", "for example" or "for instance" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary", "for example" or "for instance" is intended to present relevant concepts in a specific manner.

[0130] In the description of the embodiments of this application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; "and / or" in the text is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "a plurality of" means two or more than two.

[0131] In some processes described in the embodiments of this application, there are a plurality of operations or steps that appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of this application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in order or in parallel, and these operations or steps may be combined.

[0132] It should be noted that the serial numbers of the above embodiments of this application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0133] Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc) as described above and includes several instructions for causing a terminal device to execute the methods described in various embodiments of the present application.

[0134] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A method for controlling the back-drawing of a urea pump, characterized in that, The back-drawing control method of the urea pump includes: Determining a real-time cooling and pressure-holding duration and a real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate; Determining a target shutdown duration based on the real-time cooling and pressure-holding duration and the real-time injection amount, and determining a target back-drawing parameter according to the target shutdown duration; Controlling the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, performing back-drawing control of the urea pump based on the target back-drawing parameter.

2. The back-drawing control method of the urea pump according to claim 1, characterized in that, The determining of the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate includes: Determining the real-time cooling and pressure-holding duration based on the relationship between the real-time exhaust gas temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range; Determining the real-time injection amount corresponding to the real-time cooling and pressure-holding duration based on the mapping relationship between the preset cooling and heat preservation duration and the injection amount.

3. The back-drawing control method of the urea pump according to claim 2, wherein, The flow rate range includes a first flow rate range and a second flow rate range. The determining of the real-time cooling and pressure-holding duration based on the relationship between the real-time exhaust gas temperature and a preset first temperature range and the relationship between the real-time exhaust gas flow rate and a preset flow rate range includes: When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the first flow rate range, controlling the cooling and pressure-holding duration to be a first cooling and pressure-holding duration; When it is detected that the real-time exhaust gas temperature is within the first temperature range and the real-time exhaust gas flow rate is within the second flow rate range, controlling the cooling and pressure-holding duration to be a second cooling and pressure-holding duration; Wherein, the lower limit value of the first flow rate range is greater than the upper limit value of the second flow rate range, and the first pressure reduction and heat preservation duration is greater than the second pressure reduction and heat preservation duration.

4. The back-drawing control method of the urea pump according to claim 2, characterized in that, The method further includes: When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset second temperature range, controlling the cooling and pressure-holding duration to be a second cooling and pressure-holding duration; When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset third temperature range, controlling the cooling and pressure-holding duration to be a third cooling and pressure-holding duration; When it is detected that the real-time exhaust gas temperature is not within the first temperature range and the real-time exhaust gas temperature is within a preset fourth temperature range, controlling the cooling and pressure-holding duration to be a fourth cooling and pressure-holding duration; Wherein, the lower limit value of the first temperature range is greater than the upper limit value of the second temperature range, the lower limit value of the second temperature range is greater than the upper limit value of the third temperature range, the lower limit value of the third temperature range is greater than the upper limit value of the fourth temperature range, and the second cooling and pressure-holding duration, the third cooling and pressure-holding duration, and the fourth cooling and pressure-holding duration are sorted from largest to smallest as: the second cooling and pressure-holding duration, the third cooling and pressure-holding duration, the fourth cooling and pressure-holding duration.

5. The back-drawing control method of the urea pump according to claim 1, characterized in that, Before the step of determining the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate, it further includes: Obtaining an engine speed signal and an engine ignition signal; When it is detected that the engine speed signal is less than a preset speed threshold or the engine ignition signal is a preset target value, then execute the step of determining the real-time cooling and pressure-holding duration and the real-time injection amount based on the real-time exhaust gas temperature and the real-time exhaust gas flow rate, and the preset target value is used to represent that the engine is not in an ignition state; When it is detected that the engine speed signal is not less than the preset speed threshold and the engine ignition signal is not the preset target value, the steps of acquiring the engine speed signal and the engine ignition signal are re-executed.

6. The back-drawing control method of the urea pump according to claim 1, characterized in that, After the step of determining the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate, the following steps are further included: Performing a cooling and pressure maintaining process on the urea pump based on the real-time cooling and pressure maintaining duration; After the cooling and pressure maintaining ends, performing an anti-crystallization protective injection process on the urea pump based on the real-time injection amount.

7. The back-drawing control method of the urea pump according to claim 1, characterized in that The determining of the target backflow parameter according to the target shutdown duration includes: Determining the target backflow parameter corresponding to the target shutdown duration based on the mapping relationship between the preset shutdown duration and the backflow parameter, where the target backflow parameter includes a target backflow duration, a target backflow speed, a target nozzle opening duty ratio, and a target backflow frequency.

8. A back-drawing control system for a urea pump, characterized in that, The backflow control system of the urea pump includes: A first processing module, which is used to determine the real-time cooling and pressure maintaining duration and the real-time injection amount based on the real-time exhaust temperature and the real-time exhaust flow rate; A second processing module, which is used to determine the target shutdown duration based on the real-time cooling and pressure maintaining duration and the real-time injection amount, and determine the target backflow parameter according to the target shutdown duration; A third processing module, which is used to control the urea pump to be in a shutdown state, and after the shutdown duration of the urea pump reaches the target shutdown duration, perform backflow control of the urea pump based on the target backflow parameter.

9. A back-drawing control device for a urea pump, characterized in that, The backflow control device of the urea pump includes a processor, a memory, and a backflow control program of the urea pump stored on the memory and executable by the processor. When the backflow control program of the urea pump is executed by the processor, the steps of the backflow control method of the urea pump as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that, A backflow control program of the urea pump is stored on the computer-readable storage medium. When the backflow control program of the urea pump is executed by the processor, the steps of the backflow control method of the urea pump as described in any one of claims 1 to 7 are implemented.

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