Control method and device of urea supply device and vehicle

Abstract

The invention relates to a control method and device of a urea supply device and a vehicle in the technical field of vehicles, and the control method of the urea supply device comprises the steps that it is determined that parking conditions are met, and a set amount of urea solution is provided for a selective catalytic reduction reactor; wherein the urea solution is stored in the selective catalytic reduction reactor and is used for reacting with nitrogen oxide in exhaust gas when the engine is started next time. On the basis, in the urea unfreezing period, the urea supply device cannot provide a urea solution for the selective catalytic reduction reactor, and urea stored in the selective catalytic reduction reactor reacts with nitrogen oxide in exhaust gas in the urea unfreezing period, so that the concentration of the nitrogen oxide in the exhaust gas is reduced; and substandard vehicle exhaust caused by unfreezing time of the urea is prevented.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicles, and in particular, to a control method, device and vehicle for a urea supply device. Background Art

[0002] A Selective Catalytic Reduction (SCR) reactor, whose working principle is: decomposing urea into ammonia gas, and under the action of a catalyst, the ammonia gas reacts with nitrogen oxides (NO X ) in an oxidation-reduction reaction to convert the nitrogen oxides into harmless nitrogen gas and water, thereby reducing the concentration of nitrogen oxides in the exhaust gas.

[0003] In the related art, the urea supply device of a vehicle has a low-temperature icing phenomenon. The icing positions mainly include the urea tank, the liquid inlet pipe and the nozzle. Usually, heating devices are arranged at the urea tank and the liquid inlet pipe, and the heating devices are used to heat the urea tank and the liquid inlet pipe to prevent urea from icing. However, the above method ignores that the frozen urea solution needs to be heated for a certain time to thaw. During the urea thawing period, the urea solution cannot be provided to the selective catalytic reduction reactor, resulting in the treatment effect of the selective catalytic reduction reactor not meeting the standard. Summary of the Invention

[0004] In order to solve the above technical problems, the present disclosure provides a control method, device and vehicle for a urea supply device.

[0005] In a first aspect, the present disclosure provides a control method for a urea supply device, including:

[0006] Determining that a parking condition is met, and providing a set amount of urea solution to the selective catalytic reduction reactor;

[0007] Wherein, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the engine is started next time.

[0008] Optionally, after providing the set amount of urea solution to the selective catalytic reduction reactor, the control method further includes:

[0009] Controlling a urea pump to suck the urea solution in the liquid inlet pipe back into the urea tank.

[0010] Optionally, the control method further includes:

[0011] Obtaining the ambient temperature when the vehicle is started and the urea temperature in the urea tank;

[0012] Based on any one of the ambient temperature and the urea temperature being less than a set temperature threshold, controlling a heating device to heat the urea solution in the urea tank.

[0013] Optionally, before providing a set amount of urea solution to the selective catalytic reduction reactor, the control method further includes:

[0014] Determining the set amount based on the heating duration of the heating device and historical exhaust data within the heating duration.

[0015] Optionally, the historical exhaust data includes exhaust gas flow rate and nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor; the determining the set amount based on the heating duration of the heating device and historical exhaust data within the heating duration includes:

[0016] Calculating the theoretical demand of the urea solution according to the following formula:

[0017] m = (Q 排气 × C1 × K1 × M1 × T1) / (M2 × K2);

[0018] Determining the set amount based on the theoretical demand; the set amount is greater than or equal to the theoretical demand;

[0019] wherein, m represents the theoretical demand of the urea solution, Q 排气 represents the exhaust gas flow rate, C1 represents the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor, K1 represents the ammonia-nitrogen molar ratio, K2 represents the catalyst efficiency, M1 represents the molar mass of urea, M2 represents the average molar mass of nitrogen oxides, and T1 represents the heating duration of the heating device.

[0020] Optionally, the control method further includes:

[0021] Based on the nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor being greater than a set concentration threshold, increasing the set amount of urea solution provided to the selective catalytic reduction reactor next time.

[0022] Optionally, the control method further includes:

[0023] Adjusting the flow rate and / or liquid supply duration of the urea solution provided to the selective catalytic reduction reactor next time based on the comparison result between the actual supply amount of the urea solution and the set amount.

[0024] Optionally, the determining of meeting the parking condition includes:

[0025] Obtaining the engine speed;

[0026] Based on the engine speed being equal to zero and the duration being greater than or equal to a set duration, determining that the parking condition is met.

[0027] In a second aspect, the present disclosure also provides a control device for a urea supply device, including:

[0028] a control module configured to determine that a parking condition is met and supply a set amount of urea solution to the selective catalytic reduction reactor;

[0029] wherein the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the vehicle is started next time.

[0030] In a third aspect, the present disclosure also provides a vehicle, including: a memory and a processor;

[0031] The processor executes the steps of any one of the above urea supply device control methods by calling a program or instruction stored in the memory.

[0032] The technical solution provided by the present disclosure has the following advantages compared with the prior art:

[0033] The control method, device and vehicle for the urea supply device provided by the present disclosure. The control method for the urea supply device includes: determining that a parking condition is met and supplying a set amount of urea solution to the selective catalytic reduction reactor; wherein the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the engine is started next time. Based on this, during the urea thawing period, the urea supply device cannot supply urea solution to the selective catalytic reduction reactor. During this period, the urea stored in the selective catalytic reduction reactor is used to react with nitrogen oxides in the exhaust gas, thereby reducing the concentration of nitrogen oxides in the exhaust gas and preventing the vehicle's exhaust emissions from not meeting the standards due to the urea thawing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0036] Figure 1 FIG. is a schematic structural diagram of an SCR urea injection system provided by an embodiment of the present disclosure;

[0037] Figure 2 FIG. is a schematic flow chart of a control method for a urea supply device provided by an embodiment of the present disclosure;

[0038] Figure 3Schematic flowchart of another control method for the urea supply device provided by the embodiments of the present disclosure;

[0039] Figure 4 Refined flowchart of "determining a set amount based on the heating duration of the heating device and historical exhaust data during the heating duration" provided by the embodiments of the present disclosure;

[0040] Figure 5 Refined flowchart of "determining that the parking condition is met" provided by the embodiments of the present disclosure;

[0041] Figure 6 Schematic diagram of input signals for the control method of the urea supply device provided by the embodiments of the present disclosure;

[0042] Figure 7 Schematic flowchart of yet another control method for the urea supply device provided by the embodiments of the present disclosure;

[0043] Figure 8 Schematic structural diagram of the control device for the urea supply device provided by the embodiments of the present disclosure;

[0044] Figure 9 Schematic structural diagram of a vehicle provided by the embodiments of the present disclosure. Detailed implementation manners

[0045] In order to more clearly understand the above objects, features, and advantages of the present disclosure, the solutions of the present disclosure will be further described below. It should be noted that, without conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other.

[0046] Many specific details are set forth in the following description in order to provide a thorough understanding of the present disclosure, but the present disclosure may be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present disclosure, rather than all the embodiments.

[0047] Figure 1 Schematic structural diagram of an SCR urea injection system provided by the embodiments of the present disclosure. Refer to Figure 1 , the SCR urea injection system includes a selective catalytic reduction reactor 1, an oxidation type particulate trap 2, a urea supply device 3, a nitrogen oxide sensor 4, a temperature sensor 5, a differential pressure sensor 6, and a urea injection control unit 7.

[0048] Among them, the urea supply device 3 includes a urea tank 31, a liquid inlet pipe 32, and a nozzle 33. A urea pump is integrated in the urea tank 31 ( Figure 1(not shown in the figure), the urea pump is used to pump the urea solution in the urea tank 31 to the liquid inlet pipe 32 and spray it into the selective catalytic reduction reactor 1 through the nozzle 33. The urea pump also has an anti-suction function. When it is determined that the vehicle stops, the urea pump is controlled to suck the remaining urea solution in the liquid inlet pipe 32 back into the urea tank 31 to avoid urea residue in the liquid inlet pipe 32 causing pipeline blockage.

[0049] A temperature sensor ( Figure 1 (not shown in the figure) and a heating device ( Figure 1 (not shown in the figure) are also integrated in the urea tank 31. The temperature sensor is used to detect the urea temperature in the urea tank 31. When either the urea temperature or the ambient temperature is less than the set temperature threshold, the urea injection control unit 7 controls the heating device to heat the urea solution in the urea tank 31 to prevent the urea solution in the urea tank 31 from freezing.

[0050] A liquid level sensor is also integrated in the urea tank. The liquid level sensor is used to detect the remaining amount of the urea solution in the urea tank. When the detected remaining amount of urea is less than the set threshold, the urea injection control unit 7 generates an alarm message and displays the alarm message on at least one of the vehicle's instrument panel, display screen, and head-up display system to remind the user to replenish the urea solution.

[0051] A urea injection sensor is provided at the nozzle to detect the actual supply amount of the urea solution. When the detected actual supply amount of the urea solution is zero, it indicates that the nozzle is blocked. The urea injection control unit 7 generates an alarm message and displays the alarm message on at least one of the vehicle's instrument panel, display screen, and head-up display system to remind the user to unblock the nozzle or send it for inspection and repair.

[0052] Nitrogen oxide sensors 4 and temperature sensors 5 are respectively provided at the inlet and outlet of the selective catalytic reduction reactor 1 and at the outlet of the oxidation type particulate trap 2. The nitrogen oxide sensor 4 is used to detect the concentration change of nitrogen oxides (NO X ) during the treatment process; the temperature sensor 5 is used to detect the temperature change of the exhaust gas during the treatment process.

[0053] Both ends of the oxidation type particulate trap 2 are respectively connected to a differential pressure sensor 6. The differential pressure sensor 6 is used to detect the differential pressure at both ends of the oxidation type particulate trap 2. The urea injection control unit 7 is used to control the oxidation type particulate trap 2 to start the regeneration operation when the differential pressure reaches the set threshold.

[0054] Among them, the urea injection control unit 7 may include the vehicle's electronic control unit (Electronic Control Unit, ECU), or may be an independently provided control unit, which is not limited here.

[0055] An embodiment of the present disclosure provides a control method for a urea supply device, which is executed by a urea injection control unit in the above SCR urea injection system. An exemplary description of the control method for the urea supply device provided by the embodiment of the present disclosure is given below.

[0056] As Figure 2 shown, it is a schematic flowchart of a control method for a urea supply device provided by the present disclosure. Referring to Figure 2 , the control method for the urea supply device includes the following steps:

[0057] S100. Determine that the parking condition is met, and supply a set amount of urea solution to the selective catalytic reduction reactor.

[0058] Among them, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the engine is started next time.

[0059] The set amount includes a set liquid supply volume and / or a set liquid supply duration.

[0060] Exemplarily, when it is determined that the parking condition is met, a set volume of urea solution is supplied to the selective catalytic reduction reactor. Taking the concentration of the urea solution as 32.5% as an example, the value range of the set liquid supply volume is 5 - 25 ml.

[0061] Exemplarily, when it is determined that the parking condition is met, a urea solution with a set duration is supplied to the selective catalytic reduction reactor. Taking the concentration of the urea solution as 32.5% and the flow rate as 80 ml / h as an example, the value range of the set liquid supply duration is 5 - 15 s.

[0062] In this embodiment, in combination with Figure 1 , when it is determined that the parking condition is met, the urea supply device 3 is controlled to supply a set amount of urea solution to the selective catalytic reduction reactor 1. At this time, the engine is in a stopped working state and no longer generates exhaust gas. The set amount of urea solution will not be consumed but stored in the selective catalytic reduction reactor 1; when the vehicle is started next time, the engine starts to work and generates exhaust gas, and the nitrogen oxides in the exhaust gas react with the urea solution pre-stored in the selective catalytic reduction reactor 1, and there is no need for the urea supply device to immediately supply urea solution to the selective catalytic reduction reactor 1.

[0063] A set amount of urea solution matches the nitrogen oxides generated during urea thawing. When the frozen urea in the urea tank is completely thawed, the residual amount of urea in the selective catalytic reduction reactor 1 is greater than or equal to zero. Before the pre-stored urea solution in the selective catalytic reduction reactor 1 is consumed, the frozen urea in the urea tank is completely thawed, and the urea supply device 3 can normally supply urea solution to the selective catalytic reduction reactor 1, thus solving the problem that the nitrogen oxide emissions do not meet the standards due to the inability to supply urea solution to the selective catalytic reduction reactor 1 during urea thawing.

[0064] The control method of the urea supply device provided by the embodiments of the present disclosure includes: determining that the parking condition is met and supplying a set amount of urea solution to the selective catalytic reduction reactor; wherein, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the engine is started next time. Based on this, during the urea thawing period, the urea supply device cannot supply urea solution to the selective catalytic reduction reactor. During this period, the urea stored in the selective catalytic reduction reactor is used to react with nitrogen oxides in the exhaust gas, thereby reducing the concentration of nitrogen oxides in the exhaust gas and preventing the vehicle exhaust emissions from not meeting the standards due to the urea thawing time.

[0065] In some embodiments, after "supplying a set amount of urea solution to the selective catalytic reduction reactor", the control method further includes the following steps:

[0066] Controlling the urea pump to suck the urea solution in the inlet pipe back into the urea tank.

[0067] Exemplarily, as Figure 3 shown, the control method further includes the following steps:

[0068] S210. Determine that the parking condition is met and supply a set amount of urea solution to the selective catalytic reduction reactor.

[0069] This step is the same as step S100. For specific explanations, please refer to the explanations at S100 and will not be repeated here.

[0070] S220. Control the urea pump to suck the urea solution in the inlet pipe back into the urea tank.

[0071] In this embodiment, when it is determined that the parking condition is met, the engine is in a stopped working state and no longer generates exhaust gas. First, control the urea pump to pump urea solution into the inlet pipe and spray the urea solution into the selective catalytic reduction reactor through the nozzle; when the spraying amount of the urea solution reaches the set amount, stop spraying the urea solution into the selective catalytic reduction reactor; control the urea pump to perform back suction to suck the remaining urea solution in the inlet pipe back into the urea tank to prevent the urea from freezing in the inlet pipe and blocking the pipeline.

[0072] In some embodiments, the control method further includes the following steps:

[0073] Obtain the ambient temperature when the vehicle starts and the urea temperature in the urea tank;

[0074] Based on either the ambient temperature or the urea temperature being less than a set temperature threshold, control the heating device to heat the urea solution in the urea tank.

[0075] In this embodiment, when the vehicle starts, obtain the ambient temperature and the urea temperature in the urea tank. When either the ambient temperature or the urea temperature is less than the set temperature threshold, it indicates that there is a possibility of urea icing. Control the heating device to heat the urea solution in the urea tank to prevent the urea solution in the urea tank from icing.

[0076] In some embodiments, the control method further includes the following steps: Obtain the ambient temperature after the vehicle starts and the urea temperature in the urea tank; Based on either the ambient temperature or the urea temperature being less than the set temperature threshold, control the heating device to heat the urea solution in the urea tank to prevent the urea solution in the urea tank from icing.

[0077] In some embodiments, before "providing a set amount of urea solution to the selective catalytic reduction reactor", the control method further includes the following steps:

[0078] Determine the set amount based on the heating duration of the heating device and the historical exhaust data during the heating duration.

[0079] In this embodiment, before the urea is completely thawed, the urea supply device cannot provide urea solution to the selective catalytic reduction reactor, and the urea stored in the selective catalytic reduction reactor reacts with the nitrogen oxides in the exhaust gas; when the urea is completely thawed, the residual amount of urea in the selective catalytic reduction reactor is greater than or equal to zero, and at this time, the urea supply device can normally provide urea solution to the selective catalytic reduction reactor.

[0080] The set amount of urea solution matches the nitrogen oxides generated during the urea thawing period. The nitrogen oxides generated during the urea thawing duration (i.e., the heating duration) can be absorbed and reacted by the urea in the selective catalytic reduction reactor, so that the nitrogen oxide emissions meet the standards.

[0081] Exemplarily, according to the previous heating duration and the historical exhaust data during the heating duration, determine the theoretical amount of nitrogen oxides generated during the previous heating duration. Based on the theoretical amount of nitrogen oxides, determine the theoretical demand for the urea solution that matches it, and determine that the set amount is greater than or equal to the theoretical demand).

[0082] Exemplarily, according to the heating duration within a preset time period and the historical exhaust gas data during the heating duration, calculate the theoretical amount of nitrogen oxides generated during each heating duration within the preset time period, and then calculate the average value of the theoretical amounts. Based on the average value, determine the theoretical demand of the urea solution that matches it, and determine that the set amount is greater than or equal to the theoretical demand.

[0083] In some embodiments, the historical exhaust gas data includes the exhaust gas flow rate and the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor. As Figure 4 shown, "determining the set amount based on the heating duration of the heating device and the historical exhaust gas data during the heating duration" includes the following steps:

[0084] S311. Calculate the theoretical demand of the urea solution according to the following formula:

[0085] m = (Q 排气 × C1 × K1 × M1 × T1) / (M2 × K2);

[0086] where m represents the theoretical demand of the urea solution;

[0087] Q 排气 represents the exhaust gas flow rate, which can be calculated through the engine power and an empirical formula;

[0088] C1 represents the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor, which is obtained through a nitrogen oxide sensor arranged at the inlet of the selective catalytic reduction reactor;

[0089] K1 represents the ammonia-nitrogen molar ratio, which can be set according to the theoretical value of the chemical reaction, and the value range is 1.0 to 1.1;

[0090] K2 represents the catalyst efficiency, that is, the conversion rate of nitrogen oxides in the selective catalytic reduction reactor; the value of K2 is related to the current state and temperature of the catalyst. The mapping relationship between K2 and the temperature can be stored in advance, and K2 is determined according to the temperature at the outlet of the selective catalytic reduction reactor;

[0091] M1 represents the molar mass of urea, approximately 60 g / mol;

[0092] M2 represents the average molar mass of nitrogen oxides, approximately 30 g / mol;

[0093] T1 represents the heating duration of the heating device.

[0094] S312. Based on the theoretical demand, determine the set amount.

[0095] In this embodiment, the set amount is greater than or equal to the theoretical demand. When the frozen urea in the urea tank is completely thawed, the residual amount of urea in the selective catalytic reduction reactor is greater than or equal to zero. The nitrogen oxides generated during the urea thawing duration (i.e., the heating duration) can be absorbed and reacted by the urea in the selective catalytic reduction reactor, so that the nitrogen oxide emissions meet the standards.

[0096] In some embodiments, the control method further includes the following steps:

[0097] Based on the nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor being greater than the set concentration threshold, increase the set amount of the urea solution provided to the selective catalytic reduction reactor next time.

[0098] In this embodiment, the nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor is detected by a nitrogen oxide sensor provided at the outlet of the selective catalytic reduction reactor, that is, the nitrogen oxide concentration after being treated by the selective catalytic reduction reactor is obtained, and the nitrogen oxide concentration is compared with the set concentration threshold, and the set amount is corrected according to the comparison result.

[0099] The specific correction method includes:

[0100] If the nitrogen oxide concentration is greater than the set concentration threshold, it indicates that the treatment effect of the selective catalytic reduction reactor does not meet the standards, the pre-stored urea solution is less, and it does not match the amount of nitrogen oxides generated during the heating duration and cannot absorb and react the nitrogen oxides generated during the heating duration. Then, when the urea solution is provided to the selective catalytic reduction reactor next time, increase the set amount.

[0101] If the nitrogen oxide concentration is less than or equal to the set concentration threshold, it indicates that the treatment effect of the selective catalytic reduction reactor meets the standards, the set amount of urea solution matches the amount of nitrogen oxides generated during the heating duration, and can absorb and react the nitrogen oxides generated during the heating duration. Then, when the urea solution is provided to the selective catalytic reduction reactor next time, do not correct the set amount.

[0102] In some embodiments, the control method further includes the following steps:

[0103] Based on the comparison result between the actual supply amount and the set amount of the urea solution, adjust the flow rate and / or the liquid supply duration of the urea solution provided to the selective catalytic reduction reactor next time.

[0104] In this embodiment, a urea injection sensor is provided at the nozzle. The urea injection sensor is used to detect the actual supply amount of the urea solution. According to the comparison result between the actual supply amount and the set amount, the set amount is corrected. The set amount is corrected by adjusting the flow rate and / or the supply duration of the urea solution. The flow rate range of the urea solution is 80 - 100 ml / h; the supply duration range of the urea solution is 5 - 15 s.

[0105] The specific correction method includes:

[0106] If the actual supply amount of the urea solution is less than the set amount, it indicates that there is less urea solution stored in advance. Then, when supplying the urea solution to the selective catalytic reduction reactor next time, increase the flow rate and / or the supply duration of the urea solution, that is, increase the actual supply amount of urea, so that the actual supply amount is greater than or equal to the set amount.

[0107] If the actual supply amount of the urea solution is greater than the set amount, it indicates that there is enough urea solution stored in advance to absorb and react with the nitrogen oxides generated during the heating duration. Then, when supplying the urea solution to the selective catalytic reduction reactor next time, do not adjust the flow rate and / or the supply duration of the urea solution.

[0108] It should be noted that the control methods for correcting the set amount provided in the above two embodiments can be selected consistently, or both can be executed, and there is no limitation here.

[0109] In some embodiments, "determining that the parking condition is satisfied" includes the following steps:

[0110] Obtain the engine speed;

[0111] Based on the engine speed being equal to zero, determine that the parking condition is satisfied.

[0112] In this embodiment, when it is detected that the engine speed is equal to zero, it indicates that the engine has stopped rotating. At this time, the engine does not generate exhaust gas. When supplying the urea solution to the selective catalytic reduction reactor at this time, the urea solution will not be consumed, but will be stored in the selective catalytic reduction reactor; when starting the vehicle next time, the engine starts to work and generates exhaust gas, and the nitrogen oxides in the exhaust gas react with the urea solution pre-stored in the selective catalytic reduction reactor, and there is no need for the urea supply device to immediately supply the urea solution to the selective catalytic reduction reactor.

[0113] In some embodiments, as Figure 5 shown, "determining that the parking condition is satisfied" includes the following steps:

[0114] S411. Obtain the engine speed.

[0115] S412. Based on the engine speed being equal to zero and the continuous duration being greater than or equal to the set duration, determine that the parking condition is satisfied.

[0116] In this embodiment, considering the temporary parking situation, by adding a duration limit condition, for the situation where the vehicle starts immediately after the user parks, there is no need to supply urea solution to the selective catalytic reduction reactor, which improves the accuracy of judgment.

[0117] In some embodiments, the value range of the set duration is 0 to 30 s.

[0118] In some embodiments, the control method further includes:

[0119] Obtain the engine speed, torque, exhaust gas flow rate, nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor, and nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor after the heating device is turned off;

[0120] Calculate the theoretical demand of the urea solution and the remaining amount of urea in the selective catalytic reduction reactor;

[0121] Determine the supply amount of the urea solution supplied to the selective catalytic reduction reactor according to the demand of the urea solution and the remaining amount of urea.

[0122] In this embodiment, after the urea solution is completely thawed, the heating device is turned off, and according to the engine speed, torque, exhaust gas flow rate, nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor, and nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor, the theoretical demand of the urea solution and the remaining amount of urea in the selective catalytic reduction reactor are calculated, and the difference between the two is the supply amount of the urea solution supplied to the selective catalytic reduction reactor.

[0123] Exemplarily, as Figure 6 shown, it is a schematic diagram of input signals of a control method for a urea supply device provided by an embodiment of the present disclosure. Referring to Figure 6 , the urea injection control unit 7 obtains corresponding operation data through the temperature sensor 5, the nitrogen oxygen sensor 4, the differential pressure sensor 6, and the sensor in the urea tank, and controls the working states of the urea pump, the liquid inlet pipe, and the nozzle 33 according to the above operation data and the control method provided in the above embodiment.

[0124] Exemplarily, as Figure 7 shown, the control method of the urea supply device includes the following steps:

[0125] S500, Start.

[0126] S501, Obtain engine parameters.

[0127] Among them, the engine parameters include but are not limited to parameters such as engine speed, torque, and power.

[0128] S502, Obtain nitrogen oxygen sensor information.

[0129] In this step, the NO concentrations at the inlet and outlet of the selective catalytic reduction (SCR) reactor and at the outlet of the oxidation type particulate trap are obtained through a nitrogen oxide sensor. X Concentration.

[0130] Among them, S501 and S502 are parallel steps, and the execution order of the two is not limited. S501 and S502 can be executed simultaneously or successively.

[0131] S503, NO in the exhaust gas X Parameter.

[0132] S504, Calculate the NO X Emission mass flow rate.

[0133] S505, Calculate the theoretical urea injection amount.

[0134] S506, Control the heating device.

[0135] In this step, when it is detected that either the urea temperature in the urea tank or the ambient temperature is less than the set temperature threshold, the heating device is controlled to heat the urea tank to prevent the urea solution in the urea tank from freezing.

[0136] S507, Actual urea injection amount.

[0137] In this step, based on the theoretical urea injection amount obtained in S505 and the combustion state obtained through S512 - S513, the actual urea injection amount is determined.

[0138] Exemplarily, the actual urea injection amount is determined according to the theoretical urea injection amount, and the actual urea injection amount is corrected according to the combustion state during the execution process.

[0139] S508, The nozzle executes the control instruction.

[0140] In this step, based on the actual urea injection amount determined in S507, the nozzle is controlled to perform the operation of injecting urea into the SCR reactor.

[0141] S509, Provide a set amount of urea to the SCR.

[0142] In this step, when it is determined that the parking condition is met, a set amount of urea is provided to the SCR. The set amount of urea is stored in the SCR reactor and is used to react with NO in the exhaust gas when the vehicle is started next time, so as to avoid the substandard SCR treatment effect before the urea is thawed. X Reaction, avoiding the substandard SCR treatment effect before the urea is thawed.

[0143] S510, SCR shutdown.

[0144] After S509 is executed, the SCR is turned off.

[0145] S511, Urea pump back suction.

[0146] In this step, the urea pump is used to suck the remaining urea solution in the liquid inlet pipe back into the urea tank to prevent the remaining urea in the liquid inlet pipe from blocking the pipeline.

[0147] S512, Engine operating condition switching.

[0148] S513, Combustion state judgment.

[0149] S514, Exhaust gas flow rate.

[0150] S515, Catalyst volume.

[0151] S516, Space velocity calculation.

[0152] S517, Obtain temperature sensor information.

[0153] S518, Catalyst temperature.

[0154] S519, Adjust catalyst efficiency.

[0155] In this embodiment, the space velocity is calculated based on the exhaust gas flow rate and the catalyst volume, and the space velocity is used to characterize the catalyst state; the catalyst temperature in the SCR reactor is obtained through the temperature sensor; according to the space velocity and the catalyst temperature, the catalyst efficiency is determined. Since the catalyst temperature is variable, the catalyst temperature is obtained in real time or at a set time interval to adjust the catalyst efficiency.

[0156] The catalyst efficiency characterizes the conversion rate of NO X in the SCR reactor, which is used to determine the actual urea injection amount. The adjustment of the catalyst efficiency will affect the actual urea injection amount determined in step S507.

[0157] S520, End.

[0158] In this embodiment, S501 - S508 and S512 - S519 are all when the vehicle is in a driving state. According to basic information such as engine speed, torque, exhaust gas flow rate, urea temperature, catalyst temperature, and NO X concentration change, the urea demand and the remaining urea in the SCR reactor are calculated, the actual urea injection amount is determined, and the nozzle is controlled to inject the corresponding amount of urea solution into the SCR reactor. The urea solution reacts with NO X in the exhaust gas to make the exhaust gas generated during the vehicle driving meet the standards.

[0159] Based on the same inventive concept, embodiments of the present disclosure further provide a reverse pre-charging control device, which is used to perform the steps of any of the above reverse pre-charging control methods and has corresponding beneficial effects. The same parts can be understood with reference to the above, and will not be elaborated hereinafter.

[0160] In some embodiments, as Figure 8 shown, it is a schematic structural diagram of a control device for a urea supply device provided by an embodiment of the present disclosure. As Figure 8 shown, the control device of the urea supply device includes: a control module, configured to determine that a parking condition is met and provide a set amount of urea solution to the selective catalytic reduction reactor; wherein, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the vehicle is started next time.

[0161] In some embodiments, the control module is further configured to: after providing the set amount of urea solution to the selective catalytic reduction reactor, control the urea pump to suck back the urea solution in the inlet pipe to the urea tank.

[0162] In some embodiments, the control module is further configured to: obtain the ambient temperature when the vehicle starts and the urea temperature in the urea tank; and based on either the ambient temperature or the urea temperature being less than a set temperature threshold, control the heating device to heat the urea solution in the urea tank.

[0163] In some embodiments, the control module is further configured to: before providing the set amount of urea solution to the selective catalytic reduction reactor, determine the set amount based on the heating duration of the heating device and the historical exhaust data during the heating duration.

[0164] In some embodiments, the historical exhaust data includes the exhaust gas flow rate and the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor; the control module is further configured to:

[0165] calculate the theoretical demand of the urea solution according to the following formula:

[0166] m=(Q 排气 ×C1×K1×M1×T1) / (M2×K2);

[0167] Based on the theoretical demand, determine the set amount; the set amount is greater than or equal to the theoretical demand;

[0168] wherein, m represents the theoretical demand of the urea solution, Q 排气 represents the exhaust gas flow rate, C1 represents the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor, K1 represents the ammonia-nitrogen molar ratio, K2 represents the catalyst efficiency; M1 represents the molar mass of urea, M2 represents the average molar mass of nitrogen oxides; T1 represents the heating duration of the heating device.

[0169] In some embodiments, the control module is further configured to: based on the nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor being greater than a set concentration threshold, increase the set amount of urea solution to be provided to the selective catalytic reduction reactor next time.

[0170] In some embodiments, the control module is further configured to: based on the comparison result between the actual supply amount and the set amount of the urea solution, adjust the flow rate and / or the liquid supply duration of the urea solution to be provided to the selective catalytic reduction reactor next time.

[0171] In some embodiments, the control module is further configured to: obtain the engine speed; and based on the engine speed being equal to zero and the duration being greater than or equal to a set duration, determine that the parking condition is met.

[0172] Based on the above embodiments, as Figure 9 shown, this is a schematic structural diagram of a vehicle provided by an embodiment of the present disclosure. Referring to Figure 9 , the vehicle includes a processor 901 and a memory 902. The processor 901 executes the steps of the control method of any urea supply device provided by the above embodiments by calling the program or instructions stored in the memory 902, and thus has the beneficial effects of the above embodiments, which will not be elaborated here.

[0173] Among them, the vehicle includes a pure electric vehicle and a hybrid vehicle.

[0174] Specifically, as Figure 9 shown, it can be set that the vehicle includes at least one processor 901, at least one memory 902, and at least one communication interface 903. The communication interface 903 is used for information transmission with external devices. It can be understood that the bus system 904 is used to realize the connection and communication between these components. The bus system 904 includes, in addition to the data bus, a power bus, a control bus, and a status signal bus. However, for the sake of clear illustration, in Figure 9 all kinds of buses are labeled as the bus system 904.

[0175] It can be understood that the memory 902 in this embodiment can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. In some embodiments, the memory 902 stores the following elements: executable units or data structures, or subsets thereof, or extended sets thereof, an operating system, and applications. In the embodiments of the present disclosure, the processor 901 executes the steps of the methods provided by the embodiments of the present disclosure by calling the programs or instructions stored in the memory 902.

[0176] The method provided by the embodiments of the present disclosure can be applied to or implemented by the processor 901. The processor 901 can be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method can be completed by the integrated logic circuit in the hardware of the processor 901 or instructions in software form. The above-mentioned processor 901 can be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0177] The steps of the method provided by the embodiments of the present disclosure can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software units in the decoding processor. The software units can be located in mature storage media in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. This storage media is located in the memory 902, and the processor 901 reads the information in the memory 902 and combines its hardware to complete the steps of the method.

[0178] The vehicle can also include one or more physical components to execute instructions generated when the processor 901 executes the method provided by the embodiments of the present disclosure. Different physical components can be arranged inside or outside the vehicle, such as a cloud server, etc. Each physical component cooperates with the processor 901 and the memory 902 to achieve the functions of the vehicle in this embodiment.

[0179] The embodiments of the present disclosure also provide a computer-readable storage medium that stores programs or instructions, and the programs or instructions cause a computer to execute the steps of any one of the control methods of the urea supply device provided in the above embodiments.

[0180] In some embodiments, when the computer-executable instructions are executed by a computer processor, they can also be used to execute the technical solutions of any of the above control methods of the urea supply device provided by the embodiments of the present disclosure to achieve corresponding beneficial effects.

[0181] From the above description of the embodiments, those skilled in the art can clearly understand that the present disclosure can be implemented by means of software and the necessary general-purpose hardware. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on this understanding, the technical solution of the present disclosure, 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 can be stored in a computer-readable storage medium, such as a floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disc of a computer, etc., including several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present disclosure.

[0182] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0183] The above are only specific embodiments of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments described herein, but rather will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a urea supply device, characterized in that, Including: Determine that the parking condition is met, and supply a set amount of urea solution to the selective catalytic reduction reactor; Wherein, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the engine is started next time.

2. The control method according to claim 1, wherein After the supply of the set amount of urea solution to the selective catalytic reduction reactor, the control method further includes: Control the urea pump to suck back the urea solution in the inlet pipe to the urea tank.

3. The control method according to claim 1, wherein Also including: Obtain the ambient temperature when the vehicle starts and the urea temperature in the urea tank; Based on either the ambient temperature or the urea temperature being less than the set temperature threshold, control the heating device to heat the urea solution in the urea tank.

4. The control method according to claim 3, wherein Before the supply of the set amount of urea solution to the selective catalytic reduction reactor, the control method further includes: Based on the heating duration of the heating device and the historical exhaust data within the heating duration, determine the set amount.

5. The control method according to claim 4, wherein The historical exhaust data includes the exhaust gas flow rate and the nitrogen oxide concentration at the inlet of the selective catalytic reduction reactor; the determining the set amount based on the heating duration of the heating device and the historical exhaust data within the heating duration includes: Calculate the theoretical demand of the urea solution according to the following formula: m = (Q 排气 × C1 × K1 × M1 × T1) / (M2 × K2); Based on the theoretical demand, determine the set amount; the set amount is greater than or equal to the theoretical demand; where m represents the theoretical demand of the urea solution, Q 排气 represents the exhaust gas flow rate, C1 represents the concentration of nitrogen oxides at the inlet of the selective catalytic reduction reactor, K1 represents the ammonia-nitrogen molar ratio, K2 represents the catalyst efficiency, M1 represents the molar mass of urea, M2 represents the average molar mass of nitrogen oxides, and T1 represents the heating duration of the heating device.

6. The control method according to claim 1, wherein Also including: Based on the nitrogen oxide concentration at the outlet of the selective catalytic reduction reactor being greater than the set concentration threshold, increase the set amount of urea solution supplied to the selective catalytic reduction reactor next time.

7. The control method according to claim 1, wherein Also including: Based on the comparison result between the actual supply amount of the urea solution and the set amount, adjust the flow rate and / or the liquid supply duration of the urea solution supplied to the selective catalytic reduction reactor next time.

8. The control method according to claim 1, wherein The determination of the satisfaction of the parking condition includes: Obtain the engine speed; Based on the engine speed being equal to zero and the continuous duration being greater than or equal to the set duration, determine that the parking condition is satisfied.

9. A control device for a urea supply device, characterized in that, Including: A control module for determining that the parking condition is met and supplying a set amount of urea solution to the selective catalytic reduction reactor; Wherein, the urea solution is stored in the selective catalytic reduction reactor and is used to react with nitrogen oxides in the exhaust gas when the vehicle is started next time.

10. A vehicle, characterized in that, Including: A memory and a processor; The processor executes the steps of the control method of the urea supply device according to any one of claims 1 to 8 by calling the program or instruction stored in the memory.

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