Injection control method, device and electronic equipment for urea injection system

Abstract

The application discloses a urea injection system injection control method, device and electronic equipment. Wherein, the method comprises: in response to the engine of the vehicle starting, and the pressure of the compressed gas cylinder in the vehicle reaching the pressure threshold, triggering the pressure building instruction for the urea tank in the vehicle; in response to the pressure building instruction, injecting the compressed gas in the compressed gas cylinder into the urea tank; based on the liquid path pressure signal of the urea tank after injection within the time window, determining the urea thawing signal in the urea tank; in response to the urea thawing signal indicating that the urea thawing is completed, triggering the urea thawing setting signal; in response to the interval time length between the time when the urea thawing setting signal is triggered and the time when the urea tank pressure building is completed being less than or equal to the time length threshold, and in response to the urea injection request, controlling the urea tank to inject urea. The application solves the technical problem that the pressure building time length of the urea system in the related art is long.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to an injection control method, apparatus, and electronic device for a urea injection system. Background Technology

[0002] In vehicle selective catalytic reduction (SCR) systems, urea aqueous solution is widely used as a reducing agent to reduce nitrogen oxides (NOx) in diesel engine exhaust. x However, in low-temperature environments, urea solution is prone to freezing, forming solid ice crystals, which can cause blockages in the injection pipeline, nozzles, and fluid passages within the urea tank, severely affecting the injection response capability during the system's cold start phase.

[0003] In related technologies, traditional urea systems typically use a pre-calibrated inherent time as the basis for judging thawing, which cannot detect the actual thawing state of urea. This causes the pressure building operation of the urea system to be forcibly delayed until the inherent time has ended, resulting in a lag in the pressure building start of the urea system and a technical problem of a long pressure building time for the urea system.

[0004] There is currently no effective solution to the technical problem of the long pressure build-up time of the urea system mentioned above. Summary of the Invention

[0005] This application provides an injection control method, apparatus, and electronic device for a urea injection system, which at least solves the technical problem of long pressure build-up time in urea systems in related technologies.

[0006] According to one aspect of the embodiments of this application, an injection control method for a urea injection system is provided. The method may include: in response to engine startup of a vehicle and the pressure in a compressed gas cylinder in the vehicle reaching a pressure threshold, triggering a pressure build-up command for a urea tank in the vehicle; in response to the pressure build-up command, injecting compressed gas from the compressed gas cylinder into the urea tank; determining a urea thawing signal in the urea tank based on a liquid circuit pressure signal within a time window after injection, wherein the liquid circuit pressure signal is used to characterize the pressure acting on the urea in the urea tank; in response to the urea thawing signal indicating that urea thawing is complete, triggering a urea thawing set signal, wherein the urea thawing set signal is used to characterize that the urea has transitioned from a frozen state to a stable injection state; and in response to a urea injection request, controlling the urea tank to inject urea, provided that the interval between triggering the urea thawing set signal and the time when the urea tank pressure build-up is complete is less than or equal to a duration threshold.

[0007] Optionally, in response to a pressure build-up command, injecting compressed gas from the compressed gas cylinder into the urea tank includes: in response to the pressure build-up command, triggering the opening of the inlet valve of the urea tank; and in response to the opening of the inlet valve, injecting compressed gas from the compressed gas cylinder into the urea tank through the inlet valve.

[0008] Optionally, during the process of injecting compressed gas into the urea tank through the inlet valve, the method further includes: detecting the gas pressure inside the urea tank; and triggering the inlet valve of the urea tank to close in response to the gas pressure reaching a preset gas pressure threshold.

[0009] Optionally, the urea thawing signal in the urea tank is determined based on the liquid pressure signal in the urea tank within a time window after injection, including: acquiring the liquid pressure signal in the urea tank within the time window; constructing a liquid pressure change curve in the urea tank based on the liquid pressure signal in the time window, wherein the liquid pressure change curve is used to characterize the pressure change of urea in the urea tank within the time window; and determining the urea thawing signal in the urea tank based on the liquid pressure change curve and a preset liquid pressure change curve.

[0010] Optionally, based on the liquid path pressure change curve and a preset liquid path pressure change curve, a urea thawing signal in the urea tank is determined, including: based on the liquid path pressure change curve and the preset liquid path pressure change curve, determining the pressure fluctuation deviation between the liquid path pressure change curve and the preset liquid path pressure change curve, wherein the pressure fluctuation deviation is used to characterize the degree to which the liquid path pressure change curve deviates from the preset liquid path pressure change curve; in response to the pressure fluctuation deviation being less than a deviation threshold, determining a urea thawing signal in the urea tank indicating that the urea in the urea tank has been thawed; or, in response to the pressure fluctuation deviation being greater than or equal to the deviation threshold, determining a urea thawing signal in the urea tank indicating that the urea in the urea tank has not been thawed.

[0011] Optionally, the method further includes: determining that the urea in the urea tank has failed to thaw in response to the interval between the triggering of the urea thawing set signal and the triggering of the pressure build-up command being longer than a duration threshold.

[0012] Optionally, when the urea in the urea tank fails to thaw, the method further includes: triggering the opening of the vent valve of the urea tank to release the gas in the urea tank through the vent valve; and controlling the urea tank to prevent urea from being sprayed in response to the completion of the gas release in the urea tank.

[0013] According to another aspect of the embodiments of this application, an injection control device for a urea injection system is also provided. The device may include: a first triggering unit, configured to trigger a pressure-building command for a urea tank in a vehicle in response to engine startup and a pressure threshold reached in a compressed gas cylinder in the vehicle; an injection unit, configured to inject compressed gas from the compressed gas cylinder into the urea tank in response to the pressure-building command; a determining unit, configured to determine a urea thawing signal in the urea tank based on a liquid circuit pressure signal within a time window after injection, wherein the liquid circuit pressure signal characterizes the pressure acting on the urea in the urea tank; a second triggering unit, configured to trigger a urea thawing set signal in response to the urea thawing signal indicating that urea thawing is complete, wherein the urea thawing set signal characterizes that the urea has transitioned from a frozen state to a stable injection state; and a control unit, configured to control the urea tank to inject urea in response to a urea injection request, provided that the interval between triggering the urea thawing set signal and the completion of urea tank pressure building is less than or equal to a time threshold.

[0014] According to another aspect of the embodiments of this application, an electronic device is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0015] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0016] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0018] According to another aspect of the embodiments of this application, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of this application.

[0019] In this embodiment, in response to the vehicle's engine starting and the pressure in the compressed gas cylinder in the vehicle reaching a pressure threshold, a pressure-building command is triggered for the urea tank in the vehicle; in response to the pressure-building command, compressed gas from the compressed gas cylinder is injected into the urea tank; based on the liquid circuit pressure signal of the urea tank within a time window after injection, a urea thawing signal is determined in the urea tank, wherein the liquid circuit pressure signal is used to characterize the pressure acting on the urea in the urea tank; in response to the urea thawing signal indicating that urea thawing is complete, a urea thawing set signal is triggered, wherein the urea thawing set signal is used to characterize that the urea has changed from a frozen state to a stable injection state; in response to the time interval between triggering the urea thawing set signal and the time when the urea tank pressure-building is complete being less than or equal to a time interval threshold, and in response to a urea injection request, the urea tank is controlled to inject urea. In other words, in this embodiment, when the vehicle's engine is started and the pressure in the compressed gas cylinder reaches the pressure threshold, the compressed gas in the compressed gas cylinder is injected into the urea tank to build up pressure in the urea tank without waiting for any preset delay. This means that the pressure building operation is completely synchronized with the engine start-up. The injection and heat release effect of the compressed gas are activated the instant the engine starts, maximizing the use of the heat energy released by the adiabatic compression of the compressed gas and actively accelerating the melting of urea ice crystals. Moreover, by using the liquid circuit pressure signal of the urea tank within the time window after the injection of compressed gas, the urea thawing signal in the urea tank can be determined, allowing for accurate control of the urea thawing process in the urea tank without relying on a pre-calibrated inherent thawing time. Compared to the traditional system that "waits for a fixed thawing time before building pressure," this application achieves zero delay in pressure building in the time dimension, thereby solving the technical problem of long pressure building time in urea systems in related technologies. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Figure 1 This is a flowchart of an injection control method for a urea injection system according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of a urea injection system according to an embodiment of this application;

[0023] Figure 3 This is a flowchart of another injection control method for a urea injection system according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of an injection control device for a urea injection system according to an embodiment of this application. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, functional component, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, functional components, or devices.

[0027] According to an embodiment of this application, an embodiment of an injection control method for a urea injection system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0028] Figure 1 This is a flowchart of an injection control method for a urea injection system according to an embodiment of this application, such as... Figure 1 As shown, the method may include the following steps.

[0029] In step S101, in response to the engine starting of the vehicle and the pressure of the compressed gas cylinder in the vehicle reaching the pressure threshold, a pressure build-up command is triggered for the urea tank in the vehicle.

[0030] In the technical solution provided by step S101 of this application, the pressure building command is used to instruct the increase of the gas pressure in the urea tank.

[0031] In this embodiment, the urea injection in the vehicle's selective catalytic reduction system relies on air pressure, powered by an onboard high-pressure compressed gas cylinder. This cylinder needs to maintain a stable pressure to ensure the urea tank has instantaneous response capability under any operating condition. However, in low-temperature environments, the presence of solid ice crystals inside the urea tank creates physical resistance to pressure transmission. If pressure build-up is initiated prematurely when the cylinder pressure is insufficient or the system is unstable, it will lead to low gas injection efficiency, increased gas path fluctuations, and even pressure oscillations or pipeline impacts. Therefore, after the vehicle's engine starts, the coolant temperature rises rapidly, allowing heat to be transferred to the urea tank to thaw the frozen urea. In this case, the pressure of the compressed gas cylinder inside the vehicle can be further assessed, and if the cylinder pressure reaches a pressure threshold, a pressure build-up command for the urea tank in the vehicle can be triggered.

[0032] Optionally, the engine start signal serves as a marker that the vehicle control system has entered operational status, indicating that the system has the timing basis to execute injection control. The setting of the compressed gas cylinder pressure threshold ensures that the compressed gas cylinder has sufficient energy reserves to support the subsequent rapid filling and adiabatic compression process of the gas phase space, preventing the pressure build-up process from being prolonged or interrupted due to insufficient gas source pressure. The pressure threshold can be systematically calibrated based on the compressed gas cylinder's design operating pressure, pipeline pressure loss characteristics, and the minimum driving pressure required for injection.

[0033] In this step, once the vehicle's engine is started and the pressure in the compressed gas cylinders inside the vehicle reaches the pressure threshold, a pressure-building command is triggered for the urea tank, increasing the pressure inside the tank. This dual-condition triggering mechanism avoids wasting gas and system losses caused by ineffective pressure building, and also prevents the localized freezing of urea caused by blindly increasing pressure when the heat source is insufficient. Furthermore, the direct physical action of compressed gas on the ice crystal interface inside the urea tank, combined with the dual acceleration mechanism of heat conduction, provides support for subsequently improving the thawing efficiency of the urea inside the tank.

[0034] In step S102, in response to the pressure build-up command, compressed gas in the compressed gas cylinder is injected into the urea tank.

[0035] In the technical solution provided by step S102 of the present invention, after responding to the pressure build-up command, the compressed gas in the compressed gas cylinder can be injected into the urea tank. After the compressed gas enters the urea tank, it undergoes near-adiabatic compression, converting the kinetic energy of the gas molecules into internal energy, resulting in a significant increase in local temperature. This temperature rise effect directly acts on the inner wall of the urea tank and the interface of adjacent ice crystals, disrupting the urea ice crystal lattice structure through heat conduction and convection, thus significantly improving the thawing rate. Compared with the traditional passive heating method that relies solely on the heat conduction of the coolant, this process has advantages such as fast response, high thermal efficiency, and concentrated energy, and does not depend on the heating cycle of an external heat source.

[0036] In this embodiment, upon receiving a pressure build-up command, the inlet valve located between the compressed gas cylinder and the gas phase space of the urea tank can be opened, allowing compressed gas to be injected into the upper gas phase region of the urea tank at a controllable flow rate. Through the adiabatic compression effect during the gas injection process, a momentary temperature rise is generated in a local area inside the urea tank, directly acting on the surface of the urea ice crystals inside the urea tank to accelerate the urea phase change process.

[0037] Optionally, during the process of injecting compressed gas into the urea tank, the gas pressure inside the urea tank can be detected in real time by the gas pressure sensor on the urea tank. When the gas pressure inside the urea tank reaches the preset gas pressure threshold, it indicates that the urea tank has completed pressure building. In this case, the air intake valve on the urea tank is closed to stop the gas intake.

[0038] In this step, compressed gas from the compressed gas cylinder is injected into the urea tank. During the injection process, the gas pressure sensor on the urea tank is used to detect the gas pressure in the urea tank in real time. When the gas pressure in the urea tank reaches the preset gas pressure threshold, the air intake valve is closed in time to stop the gas intake. This allows for accurate control of the pressure build-up process in the urea tank and achieves precise pressure build-up.

[0039] Step S103: Based on the liquid pressure signal of the urea tank within the time window after injection, determine the urea thawing signal in the urea tank.

[0040] In the technical solution provided in step S103 of the present invention, the aforementioned liquid pressure signal is used to characterize the pressure acting on the urea in the urea tank. The aforementioned urea thawing signal is used to characterize whether the urea in the urea tank has been completely thawed.

[0041] In this embodiment, after the urea tank is pressurized, the liquid pressure signal of the urea tank within a preset time window can be detected by a liquid pressure sensor configured on the urea tank, and then the urea thawing signal in the urea tank can be determined based on the liquid pressure signal.

[0042] Optionally, after detecting the liquid pressure signal of the urea tank within a time window using a liquid pressure sensor, a liquid pressure change curve of the urea tank within that time window can be constructed based on the liquid pressure signal. This liquid pressure change curve is used to reflect the change of the liquid pressure signal in the urea tank within the time window.

[0043] Optionally, after obtaining the pressure change curve of the liquid path in the urea tank, this pressure change curve can be compared and analyzed with the corresponding preset pressure change curve of the urea tank to determine the pressure fluctuation deviation of the pressure change curve of the urea tank compared with the preset pressure change curve. The preset pressure change curve is obtained from numerous low-temperature calibration experiments and is used to characterize the typical pressure response characteristics of the liquid path system under the coupling effects of inertia, damping, and compressible gas phase after the urea in the tank is disturbed by the instantaneous opening of the injection valve in a fully thawed state. It exhibits smooth, predictable micro-amplitude fluctuations without abnormal steps, oscillations, or attenuation delays.

[0044] Optionally, after obtaining the pressure fluctuation deviation, it can be compared with a preset deviation threshold. If the pressure fluctuation deviation is less than the deviation threshold, it indicates that the urea in the urea tank has completely thawed. In this case, the urea thawing signal in the urea tank can be determined to indicate that the urea in the urea tank has completely thawed. Conversely, if the pressure fluctuation deviation is greater than or equal to the deviation threshold, it indicates that the urea in the urea tank has not completely thawed. In this case, the urea thawing signal in the urea tank can be determined to indicate that the urea in the urea tank has not completely thawed.

[0045] In this step, after the urea tank is pressurized, a pressure change curve of the urea tank within the time window is constructed based on the liquid pressure signal of the injected urea tank within that time window. Then, by comparing and analyzing the pressure change curve of the urea tank with the corresponding preset pressure change curve of the urea tank, it is determined whether the urea in the urea tank has been completely thawed. This can improve the accuracy of the determination of whether the urea tank has been completely thawed and provide a reliable data basis for subsequent control of urea injection in the urea tank.

[0046] Step S104: In response to the urea thawing signal indicating that urea thawing is complete, a urea thawing set signal is triggered.

[0047] In the technical solution provided by step S104 of this application, the urea thawing positioning signal is used to characterize that the urea in the urea tank has changed from a frozen state to a stable spraying state.

[0048] In this embodiment, if the urea thawing signal in step S103 indicates that the urea in the urea tank has thawed completely, a urea thawing setting signal can be triggered. For example, the "urea injection setting signal" can be set to 1.

[0049] Optionally, the triggering of the urea thawing signal indicates that the urea in the urea tank has been transformed from an initial solid frozen state into a stable liquid medium with continuous flowability and measurability through the thermo-mechanical synergy caused by the injection of compressed gas, thus meeting the stringent requirements of the SCR system for injection accuracy, response speed and atomization quality.

[0050] In this step, after the urea thawing signal is received and the urea in the urea tank has thawed, a urea thawing set signal can be triggered to indicate that the urea in the urea tank has changed from a frozen state to a stable injection state and is ready for injection.

[0051] Step S105: In response to the time interval between the triggering of the urea thawing setting signal and the completion of urea tank pressure building being less than or equal to a time threshold, and in response to the urea injection request, control the urea tank to inject urea.

[0052] In the technical solution provided in step S105 of this application, after responding to the urea thawing setting signal, in order to ensure the safe injection of urea in the urea tank, it is necessary to further determine that the urea in the urea tank has been thawed within a specified time. Based on this, the interval between the moment when the urea thawing setting signal is triggered and the moment when the urea tank pressure is completed can be further determined, and then it can be determined whether the interval meets the requirements, so as to determine whether the urea in the urea tank has been successfully thawed.

[0053] In this embodiment, after determining the time interval between the moment when the urea thawing signal is triggered and the moment when the urea tank pressure is completed, the time interval can be compared with a time threshold to determine whether the time threshold is met.

[0054] For example, if the interval is less than or equal to the time threshold, it means the urea in the tank has thawed for the required time, and the urea has thawed successfully. In this case, in response to a urea injection request, the urea tank can be controlled to inject urea. Conversely, if the interval is longer than the time threshold, it means the urea in the tank has not thawed for the required time, i.e., the urea thawing time has exceeded the threshold, and the urea thawing has failed. In this case, even if a urea injection request is received, the urea tank is not allowed to inject urea.

[0055] Optionally, in the event that the urea tank fails to defrost, the pressure in the urea tank can be controlled to release the pressure. For example, the vent valve of the urea tank can be opened to release the gas inside the urea tank.

[0056] In this step, after the urea in the urea tank has thawed, the thawing time is used to determine whether the urea in the urea tank has thawed successfully. This ensures that the urea in the urea tank is sprayed only if it has thawed successfully, thus guaranteeing the safe spraying of the urea tank.

[0057] In steps S101 to S105 of this invention, when the vehicle engine is started and the pressure in the compressed gas cylinder reaches the pressure threshold, compressed gas from the compressed gas cylinder is injected into the urea tank to build up pressure in the urea tank without waiting for any preset delay. This means that the pressure building operation is completely synchronized with engine startup. The injection and heat release effect of the compressed gas are activated the instant the engine starts, maximizing the use of the heat energy released by the adiabatic compression of the compressed gas and actively accelerating the melting of urea ice crystals. Moreover, by using the liquid circuit pressure signal of the urea tank within the time window after the injection of compressed gas, the urea thawing signal in the urea tank can be determined, allowing for accurate monitoring of the urea thawing process in the urea tank without relying on a pre-calibrated inherent thawing time. Compared to the traditional system that "waits for a fixed thawing time before building pressure," this application achieves zero delay in pressure building in the time dimension, thereby solving the technical problem of long pressure building time in urea systems in related technologies.

[0058] The method described in this embodiment will be further described below.

[0059] As an optional embodiment, step S102, in response to the pressure build-up command, injecting compressed gas from the compressed gas cylinder into the urea tank, includes: in response to the pressure build-up command, triggering the opening of the inlet valve of the urea tank; in response to the opening of the inlet valve, injecting compressed gas from the compressed gas cylinder into the urea tank through the inlet valve.

[0060] In this embodiment, upon receiving a pressure build-up command, a high-level enable signal is immediately output to the drive circuit of the intake valve, triggering the intake valve to switch from a normally closed state to an open state. This intake valve can be a high-pressure resistant two-position two-way valve, whose valve body material and sealing structure meet the engineering requirements of the urea system for corrosive media and high-pressure conditions, possessing a dynamic characteristic with a response time of less than 20 ms, ensuring the instantaneous and reliable connection and disconnection of the gas path after the command is triggered. After the intake valve opens, a continuous fluid path is formed between the compressed gas cylinder and the urea tank's gas phase space. The compressed gas in the compressed gas cylinder flows directionally from the high-pressure side to the low-pressure side under the pressure difference, completing the gas phase filling from the compressed gas cylinder to the urea tank.

[0061] Optionally, the injection of compressed gas into the urea tank described above is not a simple gas transfer, but an active energy injection behavior with a clear thermodynamic purpose. The compressed gas undergoes adiabatic expansion as it flows through the throttling region of the inlet valve, but upon entering the urea tank, it rapidly undergoes adiabatic compression due to volume expansion. The kinetic energy of the gas molecules is converted into internal energy, forming a localized high-temperature zone near the gas-liquid interface. This thermal effect directly acts on the surface layer of solid urea inside the tank, disrupting the lattice structure of the urea ice crystals and accelerating the phase change process. Simultaneously, the injected compressed gas establishes a stable pressure field in the gas phase region of the urea tank. This pressure is transferred to the liquid urea through the gas-liquid interface, applying hydrostatic pressure to the ice crystals and further promoting their melting. This process achieves a synergistic effect of "pressure-driven" and "thermal energy input," significantly superior to passive heating methods that rely solely on coolant conduction.

[0062] As an optional embodiment, during the process of injecting compressed gas into the urea tank through the inlet valve, the method further includes: detecting the gas pressure inside the urea tank; and triggering the inlet valve of the urea tank to close in response to the gas pressure reaching a preset gas pressure threshold.

[0063] In this embodiment, during the injection of compressed gas into the urea tank through the inlet valve, real-time pressure detection and closed-loop control logic are executed simultaneously. For example, by using a gas pressure sensor installed on the top of the urea tank, the gas pressure inside the urea tank can be detected in real time, ensuring that the pressure in the gas phase space inside the urea tank remains stable within a preset safety and functional threshold range. When the gas pressure sensor detects that the gas pressure inside the urea tank has reached the preset pressure threshold, it indicates that the urea tank has completed pressure build-up. In this case, the inlet valve of the urea tank is triggered to close, stopping gas intake, avoiding overpressure risks, and ensuring the controllability of subsequent liquid circuit pressure build-up.

[0064] In this step, a stable gas pressure input is a prerequisite for a smooth rise in the liquid pressure inside the urea tank, while the precise termination of the gas pressure ensures the interpretability of the liquid pressure signal and avoids misjudgment of the thawing status due to gas pressure fluctuations or overpressure interference.

[0065] As an optional embodiment, step S103, determining the urea thawing signal in the urea tank based on the liquid pressure signal in the urea tank within a time window after injection, includes: acquiring the liquid pressure signal in the urea tank within the time window; constructing a liquid pressure change curve in the urea tank based on the liquid pressure signal in the time window, wherein the liquid pressure change curve is used to characterize the pressure change of urea in the urea tank within the time window; and determining the urea thawing signal in the urea tank based on the liquid pressure change curve and a preset liquid pressure change curve.

[0066] In this embodiment, after the urea tank is pressurized, the liquid pressure signal in the urea tank can be collected within a preset time window, and then the urea thawing signal in the urea tank can be determined based on the liquid pressure signal in the time window.

[0067] For example, a liquid pressure sensor installed on the urea tank detects the liquid pressure signal inside the tank within a time window, and then constructs a liquid pressure change curve based on the collected liquid pressure signal. After obtaining the liquid pressure change curve, this liquid pressure change curve is compared with a preset liquid pressure change curve to determine the urea thawing signal inside the urea tank.

[0068] Optionally, the actual collected liquid pressure change curve reflects the pressure response process of the urea tank under real-world conditions. The preset liquid pressure change curve is a theoretical reference model constructed under ideal thawing conditions. It characterizes the smooth, gradual, and low-fluctuation upward trend of the liquid pressure when the urea completely transforms from a solid to a continuous liquid state after compressed gas injection. By comparing and analyzing the measured liquid pressure change curve of the urea tank with the preset liquid pressure change curve, it can be determined whether the urea in the tank has completely thawed.

[0069] The process of determining the urea thawing signal in the urea tank based on the liquid pressure change curve and the preset liquid pressure change curve will be further described next.

[0070] As an optional embodiment, determining the urea thawing signal in the urea tank based on the liquid circuit pressure change curve and a preset liquid circuit pressure change curve includes: determining the pressure fluctuation deviation between the liquid circuit pressure change curve and the preset liquid circuit pressure change curve, wherein the pressure fluctuation deviation is used to characterize the degree to which the liquid circuit pressure change curve deviates from the preset liquid circuit pressure change curve; determining the urea thawing signal in the urea tank indicating that the urea in the urea tank has completed thawing in response to the pressure fluctuation deviation being less than a deviation threshold; or, determining the urea thawing signal in the urea tank indicating that the urea in the urea tank has not completed thawing in response to the pressure fluctuation deviation being greater than or equal to the deviation threshold.

[0071] In this embodiment, the pressure fluctuation deviation between the measured liquid pressure change curve in the urea tank and the preset liquid pressure change curve within the same time window is calculated using a sliding window algorithm or least squares fitting method. This pressure fluctuation deviation is a comprehensive measure of the difference between the two in terms of amplitude, phase, and spectral characteristics. When the pressure fluctuation deviation is less than the preset deviation threshold, it indicates that the dynamic response characteristics of the urea in the urea tank are highly consistent with the theoretical model under the fully thawed state, that is, the urea solution has been uniformly liquefied, with no agglomerates or ice crystals remaining, and its rheological characteristics meet the stable flow response required when the injection valve is opened. Therefore, the urea in the urea tank is determined to be "thawed completely," that is, the urea thawing signal in the urea tank indicates that the urea in the urea tank has been thawed completely.

[0072] Optionally, if the pressure fluctuation deviation is greater than or equal to the deviation threshold, it indicates that the urea in the urea tank has an abnormal dynamic response, such as delayed recovery after a sudden pressure drop, high-frequency oscillation, nonlinear decay, or response delay. These anomalies originate from uneven flow resistance caused by incomplete melting of the urea solution, entrainment of air bubbles, or blockage of the pipeline by solid particles. In this case, it can be determined that the urea in the tank has not completely thawed; that is, the urea thawing signal in the tank indicates that the urea thawing is incomplete. In this situation, the urea tank should be prohibited from executing injection commands to prevent poor atomization, nozzle blockage, or metering errors caused by unthawed urea entering the injection system, which could affect the nitrogen oxide conversion efficiency of the SCR system.

[0073] In this step, by comparing and analyzing the pressure change curve of the liquid circuit in the urea tank with the preset pressure change curve of the corresponding liquid circuit in the urea tank, it is determined whether the urea in the urea tank has been thawed. This ensures that the triggering of the urea thawing signal only occurs when the solution is truly capable of injection, providing a reliable, accurate, and verifiable basis for confirming the system status for vehicle emission control.

[0074] As an optional implementation, the method further includes: determining that the urea in the urea tank has failed to thaw in response to an interval between the time when the urea thawing setting signal is triggered and the time when the urea tank pressure build-up is completed being greater than a duration threshold.

[0075] In this embodiment, the aforementioned time threshold is set based on thermo-mechanical coupling kinetic calibration data under typical low-temperature conditions. Its value represents the theoretically maximum allowable time required from the completion of urea tank pressurization to the completion of urea thawing within the tank. This time threshold comprehensively considers multiple factors, including urea physical properties, tank heat capacity, insulation structure, ambient temperature boundaries, and gas source pressure stability, representing the upper limit time window for the urea injection system to complete thawing under normal operating conditions. If a urea thawing signal is not obtained within this window, it indicates that the liquid pressure has not stabilized as expected, the urea has not achieved a complete transition from solid ice crystals to a continuous liquid state, and the system is in an abnormal state.

[0076] Optionally, the interval between the triggering of the urea thawing signal and the completion of pressure build-up in the urea tank is detected, and this interval is compared with a time threshold. If the comparison indicates that the interval is longer than the time threshold, it indicates that the urea thawing in the urea tank has timed out. In this case, it is determined that the urea thawing in the urea tank has failed, that is, the urea in the urea tank has failed to complete the flow conversion to achieve injection capability within an acceptable time range. The injection blockage state will continue to be maintained to prevent unmelted urea from entering the injection circuit and causing irreversible failures such as metering inaccuracies, nozzle blockage, or poor atomization.

[0077] In this step, the interval between "pressure build-up triggering and thawing signal triggering" is introduced as a systematic performance constraint parameter, constructing a dual criterion of "functional completion" and "engineering timeliness." This timing constraint mechanism not only ensures that urea thawing is physically achieved, but also mandates that it be completed within a specified time window, effectively suppressing "pseudo-thawing" states caused by sensor malfunctions, poor heat conduction, or extreme environmental temperature deterioration, thus ensuring vehicle emission compliance.

[0078] As an optional implementation, when the urea in the urea tank fails to thaw, the method further includes: triggering the vent valve of the urea tank to open, releasing the gas in the urea tank through the vent valve; and controlling the urea tank to prevent urea injection in response to the completion of the gas release in the urea tank.

[0079] In this embodiment, if the urea in the urea tank fails to thaw, it indicates that the urea in the tank has not completed an effective phase change, and the urea liquid path still lacks stable flow. Maintaining high pressure in the tank at this time not only fails to support injection requirements but may also cause unmelted urea to partially break down under high pressure, block pipelines, or enter the injector flow channel, leading to deterioration of metering accuracy, nozzle crystallization, or permanent damage. Therefore, an exhaust valve enable signal can be output to drive the urea tank's exhaust valve from a locked state to an open state, establishing a pressure relief path between the urea tank's gas phase space and the atmosphere. The exhaust process follows unsteady gas expansion dynamics; the compressed gas in the tank is rapidly discharged under the pressure difference, and the gas pressure decreases exponentially until the gas pressure sensor in the urea tank reports that the gas pressure in the urea tank is below a safe threshold, confirming that the gas release in the urea tank is complete.

[0080] Optionally, after the gas in the urea tank has been released, the urea injection enable signal can be forcibly set to the disabled state, locking the drive circuit of the injection solenoid valve. Regardless of whether an injection request is received from the vehicle controller, it will not respond, ensuring that the injection function cannot be accidentally activated in the event of a fault.

[0081] In this step, if the urea in the urea tank fails to thaw, the mechanical energy stored in the urea injection system is eliminated through active pressure relief, preventing high-pressure impacts and structural damage caused by foreign object blockage or incomplete liquefaction of liquid urea. By forcibly stopping injection, undissolved urea particles are prevented from entering the SCR catalyst, causing catalyst poisoning or carrier blockage, thus ensuring the long-term reliability of the aftertreatment system.

[0082] The technical solutions of the embodiments of this application will be illustrated below with reference to preferred embodiments.

[0083] In vehicle SCR systems, urea aqueous solution is widely used as a reducing agent to reduce nitrogen oxides (NOx) in diesel engine exhaust. xHowever, in low-temperature environments, urea solution is prone to freezing, forming solid ice crystals that can block the fluid pathways in the injection pipes, nozzles, and urea tank, severely affecting the injection response capability during the cold start phase of the system. Traditional urea systems typically use a pre-calibrated inherent time as the basis for thawing judgment, failing to detect the actual thawing state of the urea. This forces the pressure-building operation of the urea system to be delayed until after the inherent time has elapsed, resulting in a lag in the pressure-building start-up of the urea system and consequently affecting the injection response capability during the cold start phase. This presents a technical problem of a long pressure-building time for urea systems.

[0084] However, this application provides an injection control method for a urea injection system. When the vehicle engine starts and the pressure in the compressed gas cylinder reaches a pressure threshold, the compressed gas in the compressed gas cylinder is injected into the urea tank to build up pressure in the urea tank without waiting for any preset delay. This means that the pressure building operation is completely synchronized with the engine start-up. The injection and heat release effect of the compressed gas are activated the instant the engine starts and the coolant temperature is still low, maximizing the use of the heat energy released by the adiabatic compression of the compressed gas and actively accelerating the melting of urea ice crystals. Moreover, by using the liquid circuit pressure signal of the urea tank within the time window after the injection of compressed gas, the urea thawing signal in the urea tank can be determined, and the thawing process of the urea in the urea tank can be accurately grasped without relying on a pre-calibrated inherent thawing time. Compared with the traditional system that "waits for a fixed thawing time before building up pressure", this application achieves zero delay in the pressure building start-up in the time dimension, thereby solving the technical problem of long pressure building time in urea systems in related technologies.

[0085] Figure 2 This is a schematic diagram of a urea injection system according to an embodiment of this application, as shown below. Figure 2 As shown, the urea injection system includes: an air source, an air filter, an intake valve, an exhaust valve, an air pressure sensor P1, a liquid pressure sensor P2, a urea tank, a urea filter, a urea nozzle, and a measuring cup, etc.

[0086] As the power core of the urea injection system, the air source provides high-pressure compressed air, and its pressure stability directly determines the urea tank's pressure-building capacity and injection driving force. The air source is usually supplied by the vehicle's main air cylinder or an independent air storage device. It can be a compressed air cylinder in the vehicle and is required to have sufficient capacity and rapid response capability to support multiple pressure-building cycles and instantaneous injection needs, while also meeting the operational requirement of no significant decrease in gas pressure under low-temperature environments.

[0087] The air filter is installed between the air source and the inlet valve to filter oil mist, moisture, and solid particulate impurities in the compressed gas, preventing contaminants from entering the gas phase space of the urea tank or clogging subsequent gas path components. Its filtration accuracy must meet industrial-grade cleanliness requirements to prevent impurities from chemically reacting with the urea solution or depositing inside pressure sensors and solenoid valves, ensuring the long-term reliability and control accuracy of the system.

[0088] The inlet valve is a high-pressure, corrosion-resistant 2-position 2-way solenoid valve used to directionally inject compressed gas into the gas phase space of the urea tank. Its core function is to precisely open / close the gas passage, quickly establish the gas pressure inside the tank during the pressure build-up phase, and promptly cut off the gas supply after thawing or in case of malfunction.

[0089] The exhaust valve and intake valve form a two-way control unit for controlling the airflow, used to safely release high-pressure gas from the urea tank to the atmosphere in case of urea thawing failure, system maintenance, or shutdown. Its function is to eliminate residual pressure inside the tank and prevent incompletely thawed solid urea from mechanically breaking apart or forming localized high-pressure zones under high pressure.

[0090] Gas pressure sensor P1 is used to acquire gas pressure signals inside the tank in real time to monitor the progress and endpoint determination of the pressure build-up process. Its output signal serves as feedback for the closure of the inlet valve and is also used to indirectly evaluate the gas path sealing and gas injection efficiency. The sensor must have high accuracy, fast response (≤10 ms), and anti-condensation characteristics to ensure long-term stable operation in low temperature and high humidity environments, providing a reliable closed-loop basis for pressure build-up control.

[0091] The liquid pressure sensor P2 is installed in the liquid pipeline between the urea tank outlet and the nozzle to measure the liquid pressure of the liquid urea in the tank. Its signal reflects the viscosity change, phase change release, and enhanced fluid mobility characteristics of urea during the transition from solid ice crystals to liquid. By analyzing the pressure change rate and fluctuation mode, the thawing completion status can be determined.

[0092] Urea tanks are storage and thawing containers that contain solid or liquid urea solutions. Their structural design needs to optimize the heat conduction path (e.g., interlayer insulation, contact with the heat exchange surface of the coolant) and reserve gas phase space to withstand the pressure of compressed gas injection.

[0093] The urea filter is located at the liquid outlet and is used to filter out crystal particles, precipitates and impurities in the urea solution to prevent them from entering subsequent injection elements. It needs to have a high throughput, low flow resistance and anti-clogging design to ensure stable operation in the non-uniform liquid mixture that may exist in the early stage of thawing. It provides a clean medium for the urea nozzle and is a key protective unit to ensure injection accuracy and system life.

[0094] The urea nozzle is a high-precision electromagnetically controlled injection element used to spray liquid urea into the exhaust pipe in an atomized form. Its injection volume, spray cone angle, and response speed directly affect the SCR aftertreatment efficiency. The urea nozzle is only activated when the defrost setting signal is valid and the injection request is legitimate. Its working state depends on the stable establishment of liquid pressure and the fluidity of the medium. It is the execution terminal for the final function realization of the system.

[0095] The measuring cup is a volumetric flow sensing element installed in the liquid circuit to monitor the outflow volume of urea per unit time in real time, indirectly reflecting the injection volume and system flow capacity. In this urea injection system, the measuring cup signal can serve as an auxiliary diagnostic basis for abnormal liquid circuit pressure. If there is no flow output from the measuring cup during the thawing process but the liquid circuit pressure has reached the standard, it may indicate nozzle blockage or pipeline cavitation. If the pressure has not reached the threshold but the measuring cup has an output, it may reflect that the urea has not been completely liquefied and there is a slurry flow, providing redundant judgment basis for the control logic.

[0096] Figure 3 This is a flowchart of another injection control method for a urea injection system according to an embodiment of this application, such as... Figure 3 As shown, the method includes the following steps.

[0097] Step S301: Power on / start the vehicle.

[0098] In this embodiment, the vehicle enters a cold start condition in response to a power-on signal or an engine start signal. At this time, all sensors, actuators, and communication modules are initialized to establish the operating environment for subsequent defrosting and injection control.

[0099] Step S302, system self-test.

[0100] In this embodiment, after the vehicle is powered on, a self-diagnostic procedure for the urea injection system is executed, including online detection of the air pressure sensor P1, the hydraulic pressure sensor P2, the intake valve, the exhaust valve, the communication link, and the power supply voltage. If any critical sensor or actuator detects an open circuit, short circuit, abnormal signal, or exceeding limit, a fault code will be recorded and subsequent pressure build-up will be prohibited, ensuring that control decisions are based on complete and reliable sensor input.

[0101] Step S303: Determine whether the pressure of the compressed gas cylinder has reached the pressure threshold.

[0102] In this embodiment, after confirming that the urea injection system has passed its self-test, the gas source pressure signal is read to determine whether it has reached a preset minimum pressure build-up threshold. This threshold ensures that the gas source has sufficient energy to complete effective pressure build-up and subsequent injection drive. If the gas pressure is insufficient, the system enters a waiting state until the gas source returns to a safe operating range, avoiding pressure build-up failure or lack of injection power due to insufficient gas source capacity, thus improving the robustness of the urea injection system.

[0103] Step S304: Open the air intake valve to allow air to enter the tank. Monitor the air pressure change in the urea tank through the air pressure sensor. Stop air intake when the air pressure in the urea tank reaches the target threshold.

[0104] In this embodiment, when the gas source pressure meets the requirements, the inlet valve is immediately triggered to open, injecting compressed gas into the gas phase space of the urea tank. This process is accompanied by a compression exothermic effect, with heat being conducted through the tank wall to the urea medium, accelerating the melting of solid ice crystals. The gas pressure sensor P1 provides real-time feedback on the upward trend of the gas pressure inside the tank. The control unit uses closed-loop control logic, and when the gas pressure reaches the target build-up value, the inlet valve is immediately closed, terminating the gas injection.

[0105] Step S305: Monitor the liquid pressure signal in the urea tank in real time using a liquid pressure sensor.

[0106] In this embodiment, after pressure buildup is complete, the control unit enters the thawing status monitoring phase, continuously collecting real-time pressure signals from the liquid circuit pressure sensor P2. This signal reflects the static pressure of the urea medium and the dynamic pressure fluctuations caused by phase change, and its changing characteristics are directly related to the physical process of urea transitioning from a solid to a liquid state.

[0107] Step S306: Determine whether the hydraulic pressure signal rises to the target hydraulic pressure signal.

[0108] In this embodiment, it is determined whether the liquid line pressure signal has reached a preset target liquid line pressure signal. This target liquid line pressure signal is calibrated based on the pipeline resistance of the urea injection system, the nozzle opening pressure, and the viscosity characteristics of urea. When the liquid line pressure signal rises to the target liquid line pressure signal, it indicates that the urea in the urea tank has basic fluidity, confirming that the urea pipeline pressure buildup is complete, and steps S307 and S312 are executed simultaneously. Optionally, this determination provides the first layer of physical confirmation conditions for the "urea injection ready signal set", but it is not equivalent to complete thawing.

[0109] Step S307: Urea injection signal set.

[0110] In this embodiment, after the liquid circuit pressure signal reaches the target liquid circuit pressure signal, the "urea injection signal" flag is set, indicating that the urea injection system has basic fluid drive capability and can respond to subsequent injection requests. However, this signal is only a pre-activated state, and it has not yet been confirmed whether the urea is completely liquefied, which still needs further verification.

[0111] In step S308, in response to the urea injection request, the pressure fluctuation signal in the urea tank is compared and analyzed with the theoretical urea pressure fluctuation signal to obtain the pressure deviation.

[0112] In this embodiment, when the vehicle controller issues an actual injection request, the control unit immediately acquires the liquid pressure fluctuation signal in the urea tank and compares it in real time with a pre-calibrated "theoretical urea pressure fluctuation signal." This theoretical urea pressure fluctuation signal is generated based on a fluid dynamics model of fully liquid urea at the moment of injection initiation, characterized by a typical mode of pressure drop-stabilization-recovery. The pressure deviation is the root mean square error or peak difference between the two signals in the time domain, used to quantify the flow consistency of the urea medium.

[0113] Step S309: Determine whether the pressure deviation is less than the deviation threshold.

[0114] In this embodiment, if the pressure deviation is less than a preset deviation threshold, it indicates that the actual pressure response is highly consistent with the theoretical behavior of completely liquid urea, meaning that the urea has no solid particle interference, no viscosity abrupt change, and no local blockage, and its physical state meets the requirements for stable injection. In this case, step S310 is executed. If the pressure deviation is greater than or equal to the preset deviation threshold, the process returns to step S308.

[0115] Step S310: Trigger the urea thawing success signal.

[0116] In this embodiment, when the pressure deviation meets the condition, a urea thawing success signal is triggered to activate the subsequent final state confirmation logic, serving as a prerequisite for "thawing completion setting" and enhancing the hierarchy and reliability of the control logic.

[0117] Step S311: Trigger the defrost completion signal to be set.

[0118] In this embodiment, after receiving the urea thawing success signal, a thawing completion signal can be further triggered. This thawing completion signal is the final enabling condition for injection execution, ensuring that the injection behavior is triggered only when the urea is completely thawed and the urea injection system is in a stable state.

[0119] Step S312: Begin thawing and diagnosis.

[0120] In this embodiment, after the urea tank is pressurized, the thawing diagnosis can begin, triggering a timer to start counting and recording the time interval between "pressurization command triggered" and "thawing completion signal set", serving as a quantitative indicator of whether thawing was successful for subsequent fault determination.

[0121] Step S313: Determine the time interval between the completion of pressure building in the urea tank and the setting of the thawing completion signal.

[0122] In this embodiment, the time interval between the completion of pressure building in the urea tank and the setting of the thawing completion signal is determined by a timer, providing a reliable data basis for subsequent evaluation of whether the urea in the urea tank has thawed successfully.

[0123] Step S314: Determine whether the pressure sensor is faulty and whether the interval duration is greater than the duration threshold.

[0124] In this embodiment, the validity of the gas pressure sensor P1 and the liquid pressure sensor P2 is determined (e.g., whether there is signal drift, discontinuity, or over-range); the interval duration is determined to exceed a preset duration threshold. If the sensors are normal but the duration exceeds the limit, it indicates that although there is a pressure response in the thawing process, the expected completion rate has not been achieved, and the urea injection system determines that "thawing has failed".

[0125] Step S315 triggers a urea thawing failure fault, controlling the urea injection system to depressurize.

[0126] In this embodiment, if thawing fails, a fault code is immediately output, and the exhaust valve is forcibly opened to release pressure inside the tank, eliminating residual gas pressure and preventing incompletely liquefied urea from causing mechanical stress damage or clogging of pipelines under high pressure. Simultaneously, the injection enable circuit is locked, prohibiting any injection action and entering a safety protection state to ensure the urea injection system operates without faults.

[0127] Step S316: Determine if the vehicle is powered off.

[0128] In this embodiment, if the vehicle power is turned off or the engine is shut down, the control unit enters a shutdown procedure and performs a safety depressurization operation regardless of the defrost status to prevent the system from maintaining a high-pressure state in a powerless state and to avoid potential safety risks.

[0129] Step S317: Depressurize the urea injection system.

[0130] In this embodiment, in the event of a power outage or malfunction, the exhaust valve opening process is automatically executed to completely release the gas pressure inside the urea tank, ensuring that the urea injection system is in a safe state under normal pressure when not in operation, which complies with mechanical safety design specifications.

[0131] Step S318, stop.

[0132] In this embodiment, the control process ends, and the urea injection system enters standby or hibernation state, waiting for the next vehicle start signal to trigger, completing a complete "cold start - defrost - injection - safe exit" control cycle.

[0133] In steps S301 to S318 above, when the engine starts and the compressed gas cylinder pressure reaches the pressure threshold, rapid pressure build-up in the urea tank is triggered. The exothermic effect of air compression, combined with engine warm-up, accelerates the melting of urea ice crystals in the tank, improving the urea tank's defrosting efficiency. By monitoring the dynamic changes in the liquid circuit pressure in real time, a two-level intelligent criterion is established: "pressure rise threshold → injection ready signal" and "pressure fluctuation matching degree → defrosting completion confirmation." This enables accurate identification of the defrosting state and optimal triggering of the injection timing. Furthermore, a defrosting duration monitoring and fault protection mechanism is introduced to ensure the safe shutdown of the urea injection system in abnormal defrosting scenarios, thus ensuring the safety of the urea injection system.

[0134] According to an embodiment of this application, an injection control device for a urea injection system is also provided. It should be noted that this injection control device for a urea injection system can be used to execute the injection control method of the urea injection system described in the embodiments.

[0135] Figure 4 This is a schematic diagram of an injection control device for a urea injection system according to an embodiment of this application. Figure 4 As shown, the injection control device 400 of the urea injection system may include: a first triggering unit 401, an injection unit 402, a determination unit 403, a second triggering unit 404, and a control unit 405.

[0136] The first triggering unit 401 is used to trigger a pressure build-up command for the urea tank in the vehicle in response to the start of the vehicle's engine and the pressure of the compressed gas cylinder in the vehicle reaching a pressure threshold.

[0137] The injection unit 402 is used to inject compressed gas from the compressed gas cylinder into the urea tank in response to the pressure build-up command.

[0138] The determining unit 403 is used to determine the urea thawing signal in the urea tank based on the liquid pressure signal in the time window after injection, wherein the liquid pressure signal is used to characterize the pressure acting on the urea in the urea tank.

[0139] The second triggering unit 404 is used to trigger a urea thawing set signal in response to a urea thawing signal indicating that urea thawing is complete. The urea thawing set signal is used to characterize that urea has changed from a frozen state to a stable injection state.

[0140] Control unit 405 is used to control the urea tank to inject urea in response to a urea thawing setting signal being triggered and the urea tank pressure building being completed when the interval between the triggering time is less than or equal to a time threshold, and in response to a urea injection request.

[0141] Optionally, the injection unit 402 is further configured to: trigger the opening of the air inlet valve of the urea tank in response to the pressure build-up command; and inject compressed gas in the compressed gas cylinder into the urea tank through the air inlet valve in response to the opening of the air inlet valve.

[0142] Optionally, during the process of injecting compressed gas into the urea tank through the inlet valve, the device 400 is also used to: detect the gas pressure inside the urea tank; and trigger the inlet valve of the urea tank to close in response to the gas pressure reaching a preset gas pressure threshold.

[0143] Optionally, the determining unit 403 is further configured to: acquire the liquid pressure signal in the urea tank within a time window; construct a liquid pressure change curve in the urea tank based on the liquid pressure signal in the time window, wherein the liquid pressure change curve is used to characterize the pressure change of urea in the urea tank within the time window; and determine the urea thawing signal in the urea tank based on the liquid pressure change curve and a preset liquid pressure change curve.

[0144] Optionally, the determining unit 403 is further configured to: determine the pressure fluctuation deviation between the liquid circuit pressure change curve and the preset liquid circuit pressure change curve based on the liquid circuit pressure change curve and the preset liquid circuit pressure change curve, wherein the pressure fluctuation deviation is used to characterize the degree to which the liquid circuit pressure change curve deviates from the preset liquid circuit pressure change curve; determine the urea thawing signal in the urea tank indicating that the urea in the urea tank has been thawed in response to the pressure fluctuation deviation being less than the deviation threshold; or determine the urea thawing signal in the urea tank indicating that the urea in the urea tank has not been thawed in response to the pressure fluctuation deviation being greater than or equal to the deviation threshold.

[0145] Optionally, the device 400 is further configured to: determine that the urea in the urea tank has failed to thaw in response to an interval between the moment when the urea thawing setting signal is triggered and the moment when the urea tank pressure build-up is completed being longer than a duration threshold.

[0146] Optionally, when the urea in the urea tank fails to thaw, the device 400 is further configured to: trigger the opening of the vent valve of the urea tank to release the gas in the urea tank through the vent valve; and, in response to the completion of the gas release in the urea tank, control the urea injection system to prohibit the injection of urea.

[0147] In the injection control device of the urea injection system described in this application, when the vehicle engine is started and the pressure of the compressed gas cylinder reaches the pressure threshold, the compressed gas in the compressed gas cylinder is injected into the urea tank to build up pressure in the urea tank without waiting for any preset delay. This means that the pressure building operation is completely synchronized with the engine start-up. The injection and heat release effect of the compressed gas are activated the instant the engine starts and the coolant temperature is still low, maximizing the use of the heat energy released by the adiabatic compression of the compressed gas and actively accelerating the melting of urea ice crystals. Moreover, by using the liquid circuit pressure signal of the urea tank within the time window after the injection of compressed gas, the urea thawing signal in the urea tank can be determined, and the thawing process of the urea in the urea tank can be accurately grasped without relying on a pre-calibrated inherent thawing time. Compared with the traditional system that "waits for a fixed thawing time before building up pressure", this application achieves zero delay in the pressure building start-up in the time dimension, thereby solving the technical problem of long pressure building time in urea systems in related technologies.

[0148] Embodiments of this application also provide an electronic device, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the injection control method of the urea injection system in various embodiments of the present invention during runtime.

[0149] Embodiments of this application also provide a computer-readable storage medium, which includes a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the injection control method of the urea injection system in various embodiments of the present invention.

[0150] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the injection control method of the urea injection system in various embodiments of the present invention.

[0151] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program, which, when executed by a processor, implements the injection control method of the urea injection system in various embodiments of the present invention.

[0152] The embodiments of this application also provide a computer program that, when executed by a processor, implements the injection control method of the urea injection system in the various embodiments of the present invention described above.

[0153] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0154] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0155] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0156] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0157] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0158] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0159] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling the injection of a urea injection system, characterized in that, include: In response to the start of the vehicle's engine and the pressure in the compressed gas cylinder in the vehicle reaching a pressure threshold, a pressure build-up command is triggered for the urea tank in the vehicle. In response to the pressure build-up command, compressed gas in the compressed gas cylinder is injected into the urea tank; Based on the liquid pressure signal of the urea tank within a time window after injection, the urea thawing signal in the urea tank is determined, wherein the liquid pressure signal is used to characterize the pressure acting on the urea in the urea tank. In response to the urea thawing signal indicating that the urea thawing is complete, a urea thawing setting signal is triggered, wherein the urea thawing setting signal is used to characterize that the urea has changed from a frozen state to a stable injection state. The system controls the urea tank to inject urea in response to a urea thawing signal being triggered and the urea tank pressure build-up being completed. The time interval between the triggering of the urea thawing signal and the completion of the urea tank pressure build-up is less than or equal to a time threshold. The system also controls the urea tank to inject urea in response to a urea injection request.

2. The method according to claim 1, characterized in that, In response to the pressure build-up command, injecting compressed gas from the compressed gas cylinder into the urea tank includes: In response to the pressure build-up command, the air inlet valve of the urea tank is triggered to open; In response to the opening of the air inlet valve, the compressed gas in the compressed gas cylinder is injected into the urea tank through the air inlet valve.

3. The method according to claim 2, characterized in that, During the process of injecting compressed gas into the urea tank through the inlet valve, the method further includes: Detect the air pressure inside the urea tank; In response to the air pressure reaching a preset air pressure threshold, the air inlet valve of the urea tank is triggered to close.

4. The method according to claim 1, characterized in that, Based on the liquid pressure signal in the urea tank within a time window after injection, the urea thawing signal in the urea tank is determined, including: Collect the liquid pressure signal in the urea tank within the time window; Based on the liquid pressure signal within the time window, a liquid pressure change curve in the urea tank is constructed, wherein the liquid pressure change curve is used to characterize the pressure change of urea in the urea tank within the time window. Based on the liquid pressure change curve and the preset liquid pressure change curve, the urea thawing signal in the urea tank is determined.

5. The method according to claim 4, characterized in that, Based on the liquid path pressure change curve and a preset liquid path pressure change curve, the urea thawing signal in the urea tank is determined, including: Based on the liquid circuit pressure change curve and the preset liquid circuit pressure change curve, the pressure fluctuation deviation between the liquid circuit pressure change curve and the preset liquid circuit pressure change curve is determined, wherein the pressure fluctuation deviation is used to characterize the degree to which the liquid circuit pressure change curve deviates from the preset liquid circuit pressure change curve. In response to the pressure fluctuation deviation being less than a deviation threshold, a urea thawing signal is determined within the urea tank, indicating that the urea in the urea tank has completed thawing; or... In response to the pressure fluctuation deviation being greater than or equal to the deviation threshold, the urea thawing signal in the urea tank is determined to indicate that the urea thawing in the urea tank is incomplete.

6. The method according to claim 1, characterized in that, The method further includes: If the interval between the triggering of the urea thawing signal and the completion of pressure build-up in the urea tank is greater than the duration threshold, it is determined that the urea in the urea tank has failed to thaw.

7. The method according to claim 6, characterized in that, When the urea in the urea tank fails to thaw, the method further includes: The vent valve of the urea tank is triggered to open, releasing the gas inside the urea tank through the vent valve; In response to the completion of the gas release in the urea tank, the urea tank is controlled to prevent the injection of urea.

8. A spray control device for a urea injection system, characterized in that, include: The first triggering unit is used to trigger a pressure build-up command for the urea tank in the vehicle in response to the starting of the vehicle's engine and the pressure of the compressed gas cylinder in the vehicle reaching a pressure threshold. An injection unit is used to inject compressed gas from the compressed gas cylinder into the urea tank in response to the pressure build-up command; The determining unit is used to determine the urea thawing signal in the urea tank based on the liquid pressure signal in the liquid path within a time window after injection, wherein the liquid pressure signal is used to characterize the pressure acting on the urea in the urea tank. The second triggering unit is used to trigger a urea thawing setting signal in response to the urea thawing signal indicating that the urea thawing is complete, wherein the urea thawing setting signal is used to characterize that the urea has changed from a frozen state to a stable injection state. The control unit is configured to control the urea tank to inject urea in response to a urea thawing signal being triggered and the urea tank pressure building being completed when the interval between the triggering time is less than or equal to a time threshold, and in response to a urea injection request.

9. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the method according to any one of claims 1 to 7.

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