Method, system and vehicle for detecting a trapped gas in a pipe

Abstract

The application discloses a pipeline gas trapping detection method and system and a vehicle, and relates to the technical field of vehicle thermal management. A first temperature signal for representing the temperature of a liquid phase in a pipeline is detected by a first temperature sensor; a second temperature signal for representing the temperature of a gas phase or a gas-liquid mixed phase in the pipeline is detected by a second temperature sensor; and whether the pipeline has gas trapping is determined according to the first temperature signal and the second temperature signal. The application can realize accurate and real-time detection of gas trapping by using only a conventional water temperature sensor, without adding a pressure sensor or a flow sensor, and has the advantages of low cost, high detection precision and timely response.

Description

Technical Field

[0001] This application relates to the technical field of vehicle thermal management, and in particular to a method, system and vehicle for detecting trapped air in pipelines. Background Technology

[0002] In a vehicle's liquid cooling system, as the coolant flows through the circulation pipes, air can easily accumulate and become trapped in dead corners, at the highest points of inverted U-shaped pipe structures, and within the heat exchanger cavity, creating a phenomenon known as "trapped air" or "air accumulation." The presence of trapped air can lead to problems such as poor water circulation, reduced heat exchange efficiency, localized overheating (dry burning), and abnormal noises from the cooling system, ultimately affecting the reliability and durability of the powertrain.

[0003] Currently, the detection of trapped air in vehicle cooling systems mainly relies on regular manual inspections or experience-based judgment. This method is lagging and cannot detect hidden trapped air faults in real time. Some related technologies utilize sensors for trapped air detection, such as installing pressure or flow sensors in the cooling pipes to indirectly determine the presence of trapped air by detecting air resistance. However, the detection accuracy of pressure and flow sensors is easily affected, resulting in a high false alarm rate. Other solutions infer the presence of air bubbles by monitoring changes in the cross-axis current of the pump in the cooling circuit or by detecting the temperature difference between the cold plate outlet and inlet, but these solutions also suffer from insufficient detection accuracy or high complexity. Summary of the Invention

[0004] This application provides a method, system, and vehicle for detecting trapped air in a pipeline, which improves the timeliness and accuracy of detecting trapped air in a vehicle's cooling system.

[0005] To achieve the above objectives, this application proposes a method for detecting gas entrapment in pipelines, the method comprising: A first temperature signal, used to characterize the temperature of the liquid phase inside the pipeline, is detected by a first temperature sensor. A second temperature signal, used to characterize the temperature of the gas phase or gas-liquid mixture within the pipeline, is detected by a second temperature sensor. Based on the first temperature signal and the second temperature signal, determine whether there is trapped air in the pipeline.

[0006] First, a first temperature sensor detects the liquid phase temperature within the pipeline, while a second temperature sensor detects the gas phase or gas-liquid mixture temperature. The presence of trapped air in the pipeline is then determined based on the dual temperature signals from both the liquid and gas / gas-liquid mixtures. Compared to solutions relying solely on a single temperature signal or pressure / flow rate signal, comparing and determining the dual temperature signals effectively reduces detection interference caused by external factors such as coolant flow rate and velocity fluctuations, thereby improving the accuracy of trapped air detection.

[0007] Secondly, by collecting temperature signals in real time through temperature sensors and determining air entrapment, compared with the method of manual periodic inspection, it is possible to realize real-time online detection of the air entrapment status of pipelines, shorten the detection cycle of air entrapment faults, and reduce the lag in air entrapment detection.

[0008] Finally, this detection method only requires a conventional water temperature sensor to detect trapped air, without the need for additional pressure or flow sensors, which helps control the hardware cost of the trapped air detection function in the vehicle's cooling system.

[0009] In one embodiment, the first temperature sensor and the second temperature sensor are integrated in the same water temperature sensor assembly and arranged at the same flow channel cross-section of the pipeline.

[0010] By integrating the first and second temperature sensors into the same water temperature sensor assembly, the number of sensor components and installation interfaces can be reduced, as can the number of sealing points in the cooling pipeline. This simplifies the pipeline layout and reduces the overall cost of components. Simultaneously, placing the two temperature sensors at the same flow channel cross-section ensures that the acquisition locations of the first and second temperature signals are spatially consistent. This reduces measurement deviations caused by uneven coolant temperature distribution at different locations in the flow channel, thereby improving the consistency of the raw data used for subsequent temperature difference calculations and air trapping determination. This further enhances the accuracy and reliability of air trapping detection.

[0011] In one embodiment, the step of determining whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal includes: Determine the temperature difference between the first temperature signal and the second temperature signal, the first heating rate of the first temperature signal, and the second heating rate of the second temperature signal; When the temperature difference is greater than a preset temperature difference threshold, the first heating rate is greater than a first preset rate threshold, and the second heating rate is greater than a second preset rate threshold, it is determined that there is trapped air in the pipeline.

[0012] By calculating the temperature difference between the first and second temperature signals, and simultaneously calculating the first and second heating rates, the temperature difference, the first heating rate, and the second heating rate are compared with preset temperature difference thresholds, first preset rate thresholds, and second preset rate thresholds, respectively. Only when all three exceed their respective thresholds is gas entrapment in the pipeline determined. Compared to methods that rely solely on a single temperature difference or a single heating rate, the temperature difference reflects the degree of steady-state temperature deviation between the liquid phase and the gas / gas-liquid mixture, while the heating rate reflects the dynamic trend difference in temperature change. Both jointly characterize the presence of gas entrapment from different dimensions. The joint determination using multi-dimensional characteristic parameters enhances the anti-interference capability of the determination rule, reduces the probability of misjudgment caused by instantaneous fluctuations in a single temperature signal, and thus further improves the accuracy and reliability of gas entrapment detection results.

[0013] In one embodiment, the step of determining that air entrapment exists in the pipeline is followed by: Determine the excess difference between the temperature difference and the preset temperature difference threshold, the first excess rate between the first heating rate and the first preset rate threshold, and the second excess rate between the second heating rate and the second preset rate threshold; The degree of air entrapment in the pipeline is determined based on the over-limit difference, the first over-limit rate value, and the second over-limit rate value. The degree of air entrapment includes slight air entrapment, moderate air entrapment, and severe air entrapment.

[0014] After determining that air entrapment exists in the pipeline, the following steps are taken: the excess difference between the temperature difference and the preset temperature difference threshold; the first excess rate between the first heating rate and the first preset rate threshold; and the second excess rate between the second heating rate and the second preset rate threshold. Based on these three excess values, the degree of air entrapment in the pipeline is determined as slight, moderate, or severe. By introducing the excess difference as a quantitative indicator of the severity of air entrapment, the air entrapment determination result is refined from a binary "presence / absence" to a three-level quantitative classification. This allows the air entrapment detection result to reflect the severity of air accumulation, providing a decision-making basis for matching differentiated treatment measures according to different degrees of air entrapment, and helping to improve the cooling system's refined response capability to air entrapment faults. Simultaneously, by using the excess degree of the temperature difference, the first heating rate, and the second heating rate to jointly determine the air entrapment level, the interference of abnormal fluctuations in the excess degree of a single dimension on the classification result can be reduced, improving the stability and reliability of the air entrapment level classification result.

[0015] In one embodiment, the step of determining the degree of air entrapment in the pipeline is followed by: Based on the degree of air entrapment, a corresponding degassing scheme and fault indication scheme are adopted.

[0016] After determining the degree of air entrapment in the pipeline, a corresponding degassing scheme and fault indication scheme are adopted based on the determined degree of minor, moderate, or severe air entrapment. Compared to related technologies that use a uniform treatment method for all air entrapment situations, matching different degassing schemes and indication schemes to different degrees of air entrapment allows for differentiated responses to air venting based on the severity of the air entrapment. For minor air entrapment, a lower-intensity, lower-energy-consumption degassing scheme can complete the venting, helping to reduce the energy waste caused by a uniform high-intensity degassing mode. For moderate or severe air entrapment, a higher-intensity, more thorough degassing scheme is used, helping to improve the thoroughness of air entrapment removal and reduce the probability of recurring faults due to insufficient venting. Simultaneously, matching different levels of fault indication schemes to the degree of air entrapment can prevent excessive alarms in cases of minor air entrapment and promptly prompt manual intervention in cases of severe air entrapment, improving the adaptability and effectiveness of fault indication.

[0017] In one embodiment, the step of adopting a corresponding degassing scheme and fault indication scheme according to the degree of air entrapment includes: When the degree of air entrapment is slight, the water pump is controlled to run at a first preset speed for a first preset duration to perform the first degassing operation.

[0018] When the air entrapment is mild, the water pump is controlled to run at a first preset speed for a first preset duration to perform the first degassing operation. Since the amount of gas accumulated in the pipeline is relatively small and the degree of entrapment is mild under mild conditions, only moderate water flow flushing at a low speed and for a short duration is needed to complete the degassing. High-intensity, long-duration degassing operations are unnecessary, which helps reduce the energy consumption of the water pump during the degassing process and also helps reduce the wear and tear on the water pump caused by prolonged high-speed operation. At the same time, a dedicated low-intensity degassing scheme is designed for mild air entrapment, enabling the degassing task to be completed with relatively low energy consumption, thus improving the energy waste caused by using a uniform degassing mode regardless of the degree of entrapment in related technologies.

[0019] In one embodiment, the step of adopting a corresponding degassing scheme and fault indication scheme according to the degree of air entrapment includes: When the degree of air entrapment is moderate, the water pump is controlled to run at a second preset speed for a second preset duration to perform a second degassing operation. After the second degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the second degassing operation is repeated. After the second degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a trapped air fault prompt is issued.

[0020] When the air entrapment level is moderate, the water pump is controlled to run at a second preset speed for a second preset duration to perform a second degassing operation. Compared to the first preset speed and duration used for mild air entrapment, the second preset speed is higher and the second preset duration is longer, generating a stronger water flow flushing force. This helps to flush out the more accumulated gas from dead corners or high-level areas in the pipeline, improving the degassing efficiency in moderate air entrapment scenarios. After the second degassing operation is completed, the temperature signal in the pipeline is continuously monitored. If the air entrapment is still not eliminated, the second degassing operation is repeated. The cumulative effect of multiple degassing operations further reduces the amount of residual gas in the pipeline, helping to improve the thoroughness of air entrapment removal. At the same time, if air entrapment still exists after the second degassing operation has been repeated to the preset limit, an air entrapment fault prompt is issued, allowing persistent air entrapment faults to be reported in a timely manner for manual intervention and maintenance, reducing the risk of long-term operation with hidden faults. In addition, by setting an upper limit on the number of repeated degassing operations, the energy waste and component wear caused by the continuous ineffective operation of the water pump in cases of stubborn trapped air that cannot be removed are reduced, which helps to balance the relationship between the degassing effect and the system energy consumption.

[0021] In one embodiment, the step of adopting a corresponding degassing scheme and fault indication scheme according to the degree of air entrapment includes: When the air entrapment level is severe, the water pump is controlled to run at a third preset speed for a third preset duration to perform a third degassing operation, and an air entrapment alarm is issued. After the third degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the third degassing operation is repeated. After the third degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a forced maintenance prompt will be issued and the vehicle's power output will be restricted.

[0022] When the air entrapment is severe, the water pump is controlled to run at a third preset speed for a third preset duration to perform a third degassing operation. Compared to the second preset speed and duration used for moderate air entrapment, the third preset speed is higher and the third preset duration is longer, generating a stronger water flow flushing force. This helps to quickly expel a large amount of accumulated gas from the pipeline, improving exhaust efficiency in severe air entrapment scenarios. Simultaneously with the third degassing operation, an air entrapment alarm is issued, allowing vehicle occupants or maintenance personnel to be promptly informed of a serious air entrapment fault in the cooling system, thus improving the timeliness of fault detection.

[0023] After the third degassing operation is completed, the temperature signal in the pipeline is continuously monitored. If the trapped air is still not eliminated, the third degassing operation is repeated. The cumulative effect of multiple high-intensity degassing operations further reduces the amount of residual gas in the pipeline, helping to improve the thoroughness of trapped air removal. If trapped air still exists after the third degassing operation has been repeated to the preset limit, a mandatory maintenance prompt is issued and the vehicle's power output is restricted. The mandatory maintenance prompt clearly conveys to the user the severity of the fault requiring immediate manual maintenance, improving upon the issue in the medium-level trapped air solution where only fault codes are displayed, which users may overlook the maintenance requirement. Restricting the vehicle's power output reduces the risk of the vehicle continuing to operate at high power when there is severe trapped air in the cooling system and the heat exchange efficiency is significantly reduced. This helps to reduce the risk of overheating and damage to components due to insufficient heat dissipation, improving the vehicle's operational safety under trapped air fault conditions.

[0024] Furthermore, this application also proposes a pipeline gas entrapment detection system, which includes: The water temperature detection module includes a first temperature sensor and a second temperature sensor integrated in the same water temperature sensor assembly; the first temperature sensor is used to detect a first temperature signal characterizing the temperature of the liquid phase in the pipeline, and the second temperature sensor is used to detect a second temperature signal characterizing the temperature of the gas phase or gas-liquid mixture in the pipeline. The control module is electrically connected to the first temperature sensor and the second temperature sensor respectively. The control module is used to determine whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal, and to execute the corresponding degassing control strategy and / or fault indication strategy according to the degree of trapped air.

[0025] In addition, this application also proposes a vehicle that includes the pipeline trapped air detection system as described above. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating an embodiment of the pipeline gas trap detection method of this application; Figure 2 A schematic diagram of the arrangement structure of the water temperature sensor assembly in the pipeline provided in the embodiments of this application; Figure 3 This is a schematic diagram of the architecture of an optional pipeline gas trap detection system provided in an embodiment of this application.

[0029] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0031] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0032] This application provides a method for detecting trapped air in pipelines, referring to... Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the pipeline gas trapping detection method of this application.

[0033] In this embodiment, the pipeline gas trap detection method includes steps S10~S30: Step S10: Detect a first temperature signal, which is used to characterize the liquid phase temperature in the pipeline, using a first temperature sensor. In this embodiment, the first temperature sensor is used to acquire the temperature of the liquid inside the pipeline. Coolant flows through the pipeline to dissipate heat from relevant components (e.g., engine, motor, battery pack, or heater core). When the pipeline is filled with coolant, the first temperature sensor is immersed in the coolant, and the first temperature signal it detects characterizes the temperature of the liquid phase inside the pipeline.

[0034] In practical applications, the first temperature sensor can be implemented using a negative temperature coefficient (NTC) thermistor, or other types of temperature sensing elements, such as platinum resistance temperature sensors (e.g., PT100, PT1000), thermocouples, or semiconductor temperature sensors. The first temperature sensor is installed inside the flow channel of the pipeline, with its sensing part extending into the coolant to ensure accurate sensing of the liquid phase temperature.

[0035] Optionally, the first temperature sensor continuously acquires temperature signals, and the acquisition frequency can be set according to the actual detection accuracy requirements and system computing power. In some embodiments, the acquisition frequency is 10Hz; in other embodiments, the acquisition frequency may be 5Hz, 20Hz, or other frequency values, which are not limited in this application. The first temperature sensor converts the acquired temperature signal into an electrical signal (e.g., a voltage signal or a current signal) and transmits it to the controller for subsequent processing.

[0036] Step S20: Detect a second temperature signal, which characterizes the temperature of the gas phase or gas-liquid mixture within the pipeline, using a second temperature sensor. In this embodiment, the second temperature sensor is used to collect the temperature of a region near the upper surface of the flow channel within the pipeline. When trapped gas exists within the pipeline, the gas floats above the flow channel because its density is less than that of the coolant. The second temperature sensor is at least partially exposed to the gas or located in the gas-liquid mixing region, and the second temperature signal it detects can characterize the temperature of the gas phase or gas-liquid mixture within the pipeline.

[0037] The second temperature sensor can also be implemented using temperature sensing elements such as NTC thermistors, platinum resistance temperature sensors, thermocouples, or semiconductor temperature sensors. The second temperature sensor is installed inside the flow channel of the pipeline, with its sensing element extending into the flow channel and positioned close to the upper surface of the flow channel, so as to detect the gas temperature or gas-liquid mixture temperature when trapped air is present. The second temperature sensor and the first temperature sensor can be installed independently or integrated into the same water temperature sensor assembly. The second temperature sensor converts the collected temperature signal into an electrical signal and transmits it to the controller for further processing.

[0038] In some embodiments, the first temperature sensor and the second temperature sensor may employ the same type of temperature sensing element to ensure consistency in their temperature response characteristics and accuracy, thereby reducing measurement deviations introduced by differences in sensor type. In other embodiments, the first temperature sensor and the second temperature sensor may employ different types of temperature sensing elements, which is not limited in this application.

[0039] Step S30: Determine whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal.

[0040] In this embodiment, after the controller acquires the first temperature signal transmitted by the first temperature sensor and the second temperature signal transmitted by the second temperature sensor, it determines whether there is trapped air in the pipeline based on these two temperature signals.

[0041] When the cooling system is operating normally and there is no trapped air in the pipes, the coolant fills the entire cross-section of the flow channel, and both the first and second temperature sensors are immersed in the coolant. Since the temperature distribution of the coolant at the same cross-section of the flow channel is basically uniform, the temperature value represented by the first temperature signal is basically consistent with the temperature value represented by the second temperature signal, and the difference between the two is small.

[0042] When trapped air exists in the pipeline, the gas floats on the upper surface of the flow channel. The area where the second temperature sensor is located is the gas phase or gas-liquid mixture region, while the area where the first temperature sensor is located remains the liquid phase region. Because the specific heat capacity of gas is much smaller than that of liquid, the temperature change of gas is significantly greater than that of liquid under the same heat input conditions. Therefore, the temperature value detected by the second temperature sensor will deviate significantly from the temperature value detected by the first temperature sensor. The controller can determine whether trapped air exists in the pipeline by comparing the difference between the first and second temperature signals.

[0043] Specifically, the controller can determine the presence of trapped gas based on a first temperature signal and a second temperature signal in various ways. For example, the controller can calculate the difference between the first and second temperature signals, and determine the presence of trapped gas when the difference is greater than a preset threshold; or, the controller can calculate the ratio of the second temperature signal to the first temperature signal, and determine the presence of trapped gas when the ratio exceeds a preset range; or, the controller can input the first and second temperature signals into a pre-trained classification model and determine the presence of trapped gas based on the model's output. It is understood that any implementation method that determines trapped gas by comparing the difference between the liquid phase temperature and the gas / gas-liquid mixture temperature can be used in conjunction with the above embodiments.

[0044] In one implementation, to ensure the stability and reliability of the temperature signals, the controller can filter each temperature signal after receiving the first and second temperature signals to remove transient noise interference. The filtering process can employ mean filtering, median filtering, or low-pass filtering algorithms, among others. The filtered temperature data more accurately and stably reflects the actual temperature state within the pipeline, thereby improving the data quality upon which subsequent gas trapping determination is based.

[0045] After determining whether air is trapped, the controller outputs the determination result. This determination result can be used to trigger subsequent operations such as fault recording, fault indication, or degassing control, but this application does not limit its use.

[0046] In one feasible implementation, the first temperature sensor and the second temperature sensor are integrated into the same water temperature sensor assembly and arranged at the same flow channel cross-section of the pipeline.

[0047] In some embodiments of this application, the first temperature sensor and the second temperature sensor are integrated in the same water temperature sensor assembly and arranged at the same flow channel cross-section of the pipeline.

[0048] The water temperature sensor assembly includes a sensor housing for securing both a first temperature sensor and a second temperature sensor to the pipe wall, maintaining their stable position relative to the pipe flow path. The sensor housing has mounting structures, such as threaded, snap-fit, or flanged structures, for installing the water temperature sensor assembly into mounting holes in the pipe. By integrating the two temperature sensors into a single assembly, only one mounting interface is needed in the pipe for both sensors to be installed, eliminating the need for separate mounting interfaces for each sensor. This reduces the number of pipe openings and lowers the risk of leakage.

[0049] In one implementation, the sensor housing is inserted into a mounting hole perpendicular to the centerline of the piping. A portion of the housing is located inside the piping, and another portion is located outside. The portion inside the piping has two receiving cavities to house the sensing parts of the first and second temperature sensors, respectively. The portion outside the piping has a connector interface for leading out the signal harnesses of the two temperature sensors, allowing for plug-and-play connection with the vehicle's wiring harness. A seal, such as an O-ring or gasket, is provided between the sensor housing and the mounting hole to prevent coolant leakage from the mounting interface, ensuring the sealing integrity of the piping system.

[0050] The first and second temperature sensors are arranged at the same cross-section of the pipeline. "Same cross-section" means that the sensing portions of the two sensors are located at the same position along the length of the pipeline, i.e., in the same plane perpendicular to the pipeline centerline, rather than at different points along the pipeline's length. In actual installation, the first and second temperature sensors are arranged side-by-side along the direction perpendicular to the pipeline centerline, with both sensing ends extending into the pipeline.

[0051] The sensing end of the first temperature sensor is positioned at or slightly below the centerline of the flow channel. During normal operation of the cooling system, the coolant fills the entire cross-section of the flow channel, and the sensing end of the first temperature sensor is immersed in the coolant, enabling accurate measurement of the liquid's true temperature. Even in the presence of trapped air in the pipeline, because the gas floats on the upper layer of the flow channel, the centerline and slightly below it remain filled with coolant, thus ensuring that the first temperature sensor can consistently and stably detect the liquid phase temperature.

[0052] The sensing end of the second temperature sensor is positioned near the upper surface of the flow channel. When there is no trapped air in the pipeline, the flow channel is filled with coolant, and the second temperature sensor is also immersed in the coolant. At this time, the temperature it detects is basically the same as that of the first temperature sensor. When trapped air is present in the pipeline, the gas, due to its low density, floats above the flow channel. The area where the sensing end of the second temperature sensor is located is the gas phase region or the gas-liquid mixture region. Therefore, the second temperature sensor can detect the gas temperature or the gas-liquid mixture temperature. It is understood that the specific arrangement height of the first and second temperature sensors is not limited to the above example. As long as the first temperature sensor can be stably immersed in the liquid under various operating conditions, and the second temperature sensor can at least partially contact the gas or gas-liquid mixture when trapped air is present, the technical effects of this application can be achieved.

[0053] In one possible implementation, both the first and second temperature sensors employ negative temperature coefficient (NTC) thermistors as temperature sensing elements. Each NTC thermistor is independently packaged within a sensor housing, with separate signal harnesses leading out, allowing the controller to independently acquire the two temperature signals. The two NTC thermistors can share the same positive output terminal of the controller, while their negative terminals are connected to different signal acquisition channels of the controller, thus achieving a common positive and separate negative electrical connection. In other implementations, the two temperature sensors can also employ other types of temperature sensing elements such as platinum resistance temperature sensors (e.g., PT100, PT1000), thermocouples, or semiconductor temperature sensors; this application does not limit this choice.

[0054] It should be understood that the two temperature sensors integrated within the same component can be arranged in various ways. In some embodiments, the two temperature sensors are arranged one above the other along a direction perpendicular to the pipe wall, and aligned with each other in a direction perpendicular to the pipe centerline. In other embodiments, the two temperature sensors can be arranged at an angle to the vertical, as long as they are still located at the same flow channel cross-section. In still other embodiments, the two temperature sensors can be arranged in a coaxial nested manner, with one temperature sensor located at the center (for detecting the liquid phase temperature) and the other temperature sensor located near the upper surface of the pipe wall (for detecting the gas phase or gas-liquid mixture temperature), which also achieves the effect of being integrated within the same component and located at the same flow channel cross-section. All of the above arrangements do not change the fundamental characteristic that the two temperature sensors are located at the same flow channel cross-section, nor do they affect the implementation of the technical solution of this application.

[0055] It should also be understood that the piping in actual vehicles may not be arranged horizontally, but may have tilted, bent, or inverted U-shaped forms. In these cases, descriptions such as "flow channel centerline," "flow channel centerline slightly lower," and "flow channel upper surface" should be adapted based on the actual routing of the local piping. That is, the first temperature sensor should be placed in a relatively lower liquid phase stable accumulation region in the direction of gravity, and the second temperature sensor should be placed in a relatively higher gas phase potential accumulation region in the direction of gravity. Regardless of the piping routing, as long as the two temperature sensors are placed at the same flow channel cross-section and are respectively located in the liquid phase stable region and the gas phase potential accumulation region of that cross-section, it can be considered a specific implementation of the arrangement scheme described in this application.

[0056] In some embodiments, the water temperature sensor assembly may also have a partition structure inside the sensor housing to physically isolate the sensing elements of the two temperature sensors within the housing, preventing unintended thermal conduction interference between them. For example, a layer of insulating material or an air gap may be provided between the two sensing elements, allowing each temperature sensor to independently reflect the temperature of its location and reducing measurement coupling caused by heat conduction within the housing. This structural design further enhances the independence and accuracy of dual temperature signal acquisition.

[0057] Furthermore, the overall shape and size of the water temperature sensor assembly can be adaptively adjusted according to the actual installation space and pipeline dimensions. For example, a slender housing design can be used for small-diameter pipelines, while a short and thick housing design can be used for large-diameter pipelines. Regardless of the shape, as long as the sensing parts of the two temperature sensors are located at the same flow channel cross-section and respectively arranged in the stable liquid phase region and the region where the gas phase may accumulate, it falls within the scope of the technical solution claimed in this application.

[0058] The following is combined Figure 2The water temperature sensor assembly provided in the embodiments of this application will be described in detail.

[0059] Figure 2 This is a schematic diagram of the arrangement of a water temperature sensor assembly in a pipeline, as provided in an embodiment of this application. Figure 2 As shown, the water temperature detection module mainly includes a combined water temperature sensor assembly, which integrates a first temperature sensor NTC1 and a second temperature sensor NTC2. The first temperature sensor NTC1 and the second temperature sensor NTC2 are installed together in the same sensor housing. The water temperature sensor assembly is fixed to the pipe wall (i.e., the mounting base) and partially extends into the pipe.

[0060] The first temperature sensor, NTC1, is positioned at or slightly below the centerline of the flow channel. For example... Figure 2 As shown, with the piping arranged horizontally, the sensing end of NTC1 is located in the central region or slightly below the central region of the piping flow path. When the cooling system is operating normally and the piping is filled with coolant, the sensing end of NTC1 is completely immersed in the coolant, used to detect the temperature of the liquid in the piping, thus obtaining the first temperature signal characterizing the liquid phase temperature. Because the coolant flows continuously in the piping, the temperature detected by NTC1 can reflect the temperature state of the coolant in real time.

[0061] The second temperature sensor, NTC2, is positioned near the upper surface of the flow channel. For example... Figure 2 As shown, the sensing end of the NTC2 is located in the upper region of the pipeline flow channel, that is, at a relatively high position in the direction of gravity within the cross-section of the flow channel. When trapped gas exists in the pipeline, the gas rises under the action of buoyancy due to its lower density than the coolant, and accumulates in the upper region of the flow channel. At this time, the position of the sensing end of the NTC2 is either in the gas phase region (the sensing end is completely exposed to the gas) or the gas-liquid mixture region (the sensing end is partially in contact with the gas and partially in contact with the liquid). Therefore, the NTC2 is used to detect the temperature of the gas or gas-liquid mixture in the pipeline, that is, to obtain a second temperature signal to characterize the temperature of the gas phase or gas-liquid mixture.

[0062] like Figure 2As further illustrated, the first temperature sensor NTC1 and the second temperature sensor NTC2 are arranged at the same cross-section of the pipeline. The term "same cross-section" means that the sensing parts of the two temperature sensors are located at the same position along the length of the pipeline, i.e., in the same plane perpendicular to the pipeline centerline. Within this cross-section, NTC1 is located below (in the liquid phase region), and NTC2 is located above (in the region where the gas phase may accumulate), and they are aligned with each other in the direction perpendicular to the pipeline centerline. This arrangement ensures that the temperature signals collected by NTC1 and NTC2 originate from the same location along the same length of the pipeline, eliminating the influence of temperature gradients that may exist along the flow direction at different cross-sections on the temperature difference calculation.

[0063] Continue reading Figure 2 The sensor housing penetrates the pipe wall. The outer wall of the sensor housing has a mounting structure, such as a threaded structure or a snap-fit ​​structure, for securing the water temperature sensor assembly to the mounting hole in the pipe wall. A seal (e.g., an O-ring) is provided between the sensor housing and the pipe wall. The seal surrounds the outer periphery of the sensor housing and presses against the wall of the mounting hole to prevent coolant leakage from the mounting interface. A portion of the sensor housing is located inside the pipe, and another portion is located outside the pipe. The portion inside the pipe has two receiving cavities for accommodating the temperature sensing parts of NTC1 and NTC2, respectively; the portion outside the pipe has a connector interface for leading out the signal harnesses of the two temperature sensors.

[0064] In terms of electrical connection, NTC1 and NTC2 are composed of independent NTC thermistors. Each NTC thermistor is independently packaged, with separate positive and negative leads. The two NTC thermistors can share the same positive output terminal of the controller, while their negative terminals are connected to different signal acquisition channels of the controller, thus achieving a common positive and separate negative electrical connection. In other implementations, the two NTC thermistors can also be independently connected to different acquisition ports of the controller, using independent power supply and signal circuits. The controller acquires the voltage signals of NTC1 and NTC2 through two independent signal acquisition channels, and converts each voltage signal into a corresponding temperature value to obtain the first temperature signal and the second temperature signal.

[0065] Optionally, a heat insulation structure is provided between the temperature sensing parts of NTC1 and NTC2 inside the sensor housing. For example, the cavity between the two temperature sensing parts can be filled with heat insulation material (such as foam material or aerogel with low thermal conductivity), or an air gap can be provided between the two temperature sensing parts as a heat insulation layer. By providing a heat insulation structure, heat transfer between NTC1 and NTC2 due to internal heat conduction can be reduced, allowing each temperature sensor to independently reflect the actual temperature of its location. This reduces the problem of convergence and narrowing of the detection values ​​of the two temperature sensors due to thermal conduction coupling, thereby helping to improve the differentiation and accuracy of the dual temperature signals used for subsequent gas trapping determination.

[0066] Understandable Figure 2 The illustration shown is merely an example of the arrangement of the water temperature sensor assembly in this application and does not constitute a limitation on the scope of protection of this application. For example, in some other embodiments, the specific spacing between NTC1 and NTC2 within the sensor housing can be adjusted according to factors such as pipe diameter and fluid temperature range; in still other embodiments, the insertion angle of the water temperature sensor assembly can also be adaptively adjusted according to the actual routing of the pipe and the limitations of the installation space, as long as NTC1 is located in the stable liquid phase region, NTC2 is located in the region where the gas phase may accumulate, and both are located in the same flow channel cross-section. Any technical solution that integrates dual temperature sensors based on the same inventive concept to separately detect the liquid phase temperature and the gas / gas-liquid mixture temperature falls within the scope of protection of this application.

[0067] In one feasible implementation, the step of determining whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal includes: Determine the temperature difference between the first temperature signal and the second temperature signal, the first heating rate of the first temperature signal, and the second heating rate of the second temperature signal; When the temperature difference is greater than a preset temperature difference threshold, the first heating rate is greater than a first preset rate threshold, and the second heating rate is greater than a second preset rate threshold, it is determined that there is trapped air in the pipeline.

[0068] In some embodiments of this application, after acquiring the first temperature signal transmitted by the first temperature sensor and the second temperature signal transmitted by the second temperature sensor, the controller first preprocesses the two temperature signals respectively. Since the temperature sensors may be affected by electromagnetic interference, quantization noise, and other factors during the acquisition process, causing fluctuations in the instantaneous temperature data, the controller can first filter the first and second temperature signals respectively. The filtering process can employ a mean filtering algorithm, that is, calculating the arithmetic mean of multiple temperature values ​​acquired within a preset time window, and using the average value as the valid temperature value within that time window. In other implementations, the filtering process can also employ a median filtering algorithm, a recursive average filtering algorithm, or a low-pass filtering algorithm, etc. The filtered temperature data can more realistically and stably reflect the actual temperature state within the pipeline.

[0069] After preprocessing the temperature signals, the controller determines the temperature difference ΔT between the first and second temperature signals. Specifically, the controller subtracts the temperature value represented by the first temperature signal from the temperature value represented by the filtered second temperature signal to obtain the difference ΔT. Since the first temperature sensor is located at or slightly below the centerline of the flow channel, it detects the liquid phase temperature; the second temperature sensor is located near the upper surface of the flow channel and detects the gas phase or gas-liquid mixture temperature when trapped gas is present. When trapped gas exists in the pipeline, the gas temperature is usually higher than the liquid temperature (when the cooling system is operating at high temperatures), therefore the value of the second temperature signal may be greater than the value of the first temperature signal, and the temperature difference ΔT will be positive. It should be noted that the calculation method for the temperature difference is not limited to the above-described form of "second temperature signal value minus first temperature signal value," and can also be achieved by subtracting the second temperature signal value from the first temperature signal value and taking the absolute value. This application does not limit this method.

[0070] The controller also calculates the first heating rate Vt1 of the first temperature signal and the second heating rate Vt2 of the second temperature signal in real time. The heating rate characterizes how quickly the temperature changes over time. Specifically, the controller can use a preset time interval Δt (e.g., 1 second, 2 seconds, or 5 seconds) as the calculation period to calculate the temperature change of the first and second temperature signals within that time interval. Dividing the temperature change by the time interval yields the heating rate of each temperature signal. For example, the first heating rate Vt1 is calculated as Vt1 = (T1(t2) - T1(t1)) / (t2 - t1), where T1(t1) is the first temperature value at time t1, and T1(t2) is the first temperature value at time t2. Similarly, the second heating rate Vt2 is calculated as Vt2 = (T2(t2) - T2(t1)) / (t2 - t1). In the presence of trapped gas, because the specific heat capacity of gas is much smaller than that of liquid, the temperature rises significantly faster when gas is heated than that of liquid. Therefore, the second heating rate Vt2 will show a more significant change compared to the first heating rate Vt1. In other implementations, the heating rate can also be calculated using curve fitting, that is, linearly fitting the temperature data within a time window and using the slope of the fitted line as the heating rate.

[0071] In some related technical solutions, relying solely on a single temperature signal (e.g., detecting only whether the coolant temperature has risen abnormally) to determine if a system is faulty is difficult to distinguish between air entrapment and other causes (e.g., increased engine load, increased ambient temperature, etc.), resulting in a high false alarm rate. Other solutions rely solely on the temperature difference between two temperature sensors, but this temperature difference can be momentarily abnormal due to factors such as flow fluctuations, also easily leading to false alarms.

[0072] Therefore, the controller compares the calculated temperature difference ΔT with a preset temperature difference threshold Tth, and simultaneously compares the first heating rate Vt1 with a first preset rate threshold V1th, and the second heating rate Vt2 with a second preset rate threshold V2th. The controller only determines that air entrapment exists in the pipeline when the temperature difference ΔT is greater than the preset temperature difference threshold Tth, the first heating rate Vt1 is greater than the first preset rate threshold V1th, and the second heating rate Vt2 is greater than the second preset rate threshold V2th.

[0073] The technical principle of the aforementioned joint judgment logic is as follows: If there is no trapped air in the pipeline, both temperature sensors are immersed in the coolant, and the temperature values ​​detected by both are basically the same, with the temperature difference ΔT not exceeding the preset temperature difference threshold. Simultaneously, the heating rates of both temperature sensors reflect the cooling process of the coolant, and their heating rates are basically consistent, preventing either heating rate from significantly exceeding the threshold. Only when trapped air exists in the pipeline, and the area where the second temperature sensor is located is a gas phase or a gas-liquid mixture, will the temperature value represented by the second temperature signal deviate significantly from the first temperature signal, causing the temperature difference ΔT to exceed the preset temperature difference threshold. Furthermore, the lower specific heat capacity of the gas causes the second heating rate Vt2 to change more drastically compared to the first heating rate Vt1, causing both to exceed their respective preset rate thresholds. Therefore, by simultaneously satisfying the three conditions of temperature difference ΔT exceeding the threshold, the first heating rate Vt1 exceeding the threshold, and the second heating rate Vt2 exceeding the threshold, the entrapment of air can be determined more accurately than the scheme that relies on only a single criterion. This reduces the probability of misjudgment caused by factors such as instantaneous fluctuations in coolant flow and sudden changes in ambient temperature.

[0074] The specific values ​​of the preset temperature difference threshold Tth, the first preset rate threshold V1th, and the second preset rate threshold V2th can be calibrated based on factors such as pipeline structure, coolant type, sensor installation location, and vehicle operating conditions. For example, for different vehicle models or different cooling system layouts, the above thresholds can be obtained through bench testing or actual vehicle calibration, and this application does not impose specific limitations on them.

[0075] It is understandable that the implementation method of determining gas entrapment only when all three conditions are met simultaneously—"temperature difference ΔT greater than preset temperature difference threshold", "first heating rate Vt1 greater than first preset rate threshold", and "second heating rate Vt2 greater than second preset rate threshold"—is only one optional judgment logic. In other implementation methods, the judgment logic can also be adjusted according to actual needs. For example, gas entrapment can be determined when both the temperature difference ΔT and the second heating rate Vt2 are greater than the second preset rate threshold. Alternatively, a gas entrapment risk index can be calculated by assigning different weights to the three judgment parameters, and gas entrapment can be determined when the index exceeds a preset risk threshold. Regardless of the combination of judgment methods used, the core is to use the temperature difference characteristics and heating rate differences between the liquid phase temperature and the gas / gas-liquid mixture temperature to identify gas entrapment. These variations are all equivalent substitutions or simple modifications of the technical solution of this application.

[0076] It should also be understood that when the temperature difference ΔT does not exceed the preset temperature difference threshold, or the first heating rate Vt1 does not exceed the first preset rate threshold, or the second heating rate Vt2 does not exceed the second preset rate threshold, the controller can determine that there is no trapped air in the pipeline. In this case, the cooling system can continue to operate normally and monitor, and the controller continues to acquire the two temperature signals at a preset acquisition frequency and make real-time judgments to achieve continuous monitoring of the trapped air status in the pipeline.

[0077] In one feasible implementation, the step of determining that air entrapment exists in the pipeline is followed by: Determine the excess difference between the temperature difference and the preset temperature difference threshold, the first excess rate between the first heating rate and the first preset rate threshold, and the second excess rate between the second heating rate and the second preset rate threshold; The degree of air entrapment in the pipeline is determined based on the over-limit difference, the first over-limit rate value, and the second over-limit rate value. The degree of air entrapment includes slight air entrapment, moderate air entrapment, and severe air entrapment.

[0078] In some embodiments of this application, after determining that there is trapped air in the pipeline based on the temperature difference ΔT, the first heating rate Vt1, and the second heating rate Vt2, in order to further assess the severity of the trapped air so that differentiated countermeasures can be taken for different severity levels, as an optional implementation, the degree of trapped air can be determined in the following manner.

[0079] After determining that there is trapped gas in the pipeline, the controller further determines the excess value ΔT_over between the temperature difference ΔT and the preset temperature difference threshold Tth. Specifically, the excess value ΔT_over can be obtained by subtracting the preset temperature difference threshold Tth from the temperature difference ΔT, i.e., ΔT_over = ΔT - Tth. When ΔT is greater than Tth, ΔT_over is a positive value, and its magnitude reflects the degree to which the temperature difference exceeds the normal allowable range. The greater the temperature difference exceeds the limit, the greater the deviation between the gas phase or gas-liquid mixture temperature at the location of the second temperature sensor and the liquid phase temperature, indirectly reflecting the amount or degree of gas accumulation in the pipeline.

[0080] The controller further determines a first over-limit rate value V1_over between the first heating rate Vt1 and the first preset rate threshold V1th. Specifically, the first over-limit rate value V1_over can be obtained by subtracting the first preset rate threshold V1th from the first heating rate Vt1, i.e., V1_over = Vt1 - V1th. When Vt1 is greater than V1th, V1_over is a positive value, and its magnitude reflects the degree to which the liquid phase heating rate exceeds the normal allowable range.

[0081] The controller further determines a second over-limit rate value, V2_over, between the second heating rate Vt2 and the second preset rate threshold V2th. Specifically, the second over-limit rate value V2_over can be obtained by subtracting the second preset rate threshold V2th from the second heating rate Vt2, i.e., V2_over = Vt2 - V2th. When Vt2 is greater than V2th, V2_over is a positive value, and its magnitude reflects the degree to which the heating rate of the gas phase or gas-liquid mixture exceeds the normal allowable range.

[0082] It is understood that the calculation methods for the over-limit difference ΔT_over, the first over-limit rate value V1_over, and the second over-limit rate value V2_over are not limited to the above-described "subtracting the threshold" form. In other implementations, the over-limit values ​​can also be expressed as ratios, such as ΔT_over = ΔT / Tth (the ratio of temperature difference to the threshold), V1_over = Vt1 / V1th (the ratio of the first heating rate to the threshold), and V2_over = Vt2 / V2th (the ratio of the second heating rate to the threshold). Regardless of whether a difference or ratio form is used, as long as it reflects the degree to which each parameter exceeds the corresponding threshold, it can be used in conjunction with the above implementation methods.

[0083] After obtaining the over-limit difference value ΔT_over, the first over-limit rate value V1_over, and the second over-limit rate value V2_over, the controller determines the degree of air entrapment in the pipeline based on these three over-limit values. The degree of air entrapment is divided into three levels: slight air entrapment, moderate air entrapment, and severe air entrapment.

[0084] As an optional judgment rule, when ΔT_over, V1_over, and V2_over are all within a relatively small range—that is, the temperature difference exceeds the threshold by a small margin, and the heating rates of the liquid and gas phases also exceed their respective thresholds by a small margin—the controller can determine that the current gas trapping level is slight. In a slight gas trapping state, the amount of gas accumulated in the pipes is small, having a minimal impact on the heat exchange efficiency and circulation resistance of the cooling system, and typically does not cause a significant decrease in system performance.

[0085] When ΔT_over, V1_over, and V2_over are all within a moderate range (meaning the temperature difference exceeds the threshold by a moderate amount, and the heating rates of the liquid and gas phases also exceed their respective thresholds by a moderate amount), the controller can determine that the current gas trapping level is moderate. Under moderate gas trapping conditions, a significant amount of gas accumulates in the pipes, which has a perceptible negative impact on the heat exchange efficiency of the cooling system, and components are at risk of dry burning. Appropriate degassing measures are needed to eliminate this gas.

[0086] When ΔT_over, V1_over, and V2_over are all within a large range—meaning the temperature difference exceeds the threshold by a significant margin, and the heating rates of the liquid and gas phases also exceed their respective thresholds by a significant margin—the controller can determine that the current gas entrapment level is severe. In a severe gas entrapment state, a large amount of gas accumulates in the pipeline, the heat exchange efficiency of the cooling system decreases significantly, the risk of dry burning of components is high, and problems such as localized overheating or abnormal water flow noise may occur, requiring urgent and thorough degassing measures.

[0087] For ease of explanation, the following set of example values ​​illustrates the grading method of this application. It should be understood that the following values ​​are merely examples and do not constitute any limitation on this application. Assume the preset temperature difference threshold Tth is 3℃, and the preset rate thresholds are calibrated as V1th and V2th, respectively. When ΔT_over is between 0.5℃ and 1.5℃, and V1_over and V2_over are at relatively low over-limit levels, it is determined to be slight entrapment; when ΔT_over is between 1.5℃ and 3℃, and V1_over and V2_over are at moderate over-limit levels, it is determined to be moderate entrapment; when ΔT_over exceeds 3℃, and V1_over and V2_over are at large over-limit levels, it is determined to be severe entrapment. The specific values ​​involved in the above grading rules can be calibrated according to factors such as actual pipeline structure, cooling system type, and vehicle operating conditions. Different vehicle models or different cooling systems may correspond to different grading thresholds, which this application does not specifically limit.

[0088] In determining the degree of gas entrapment, as an optional implementation method, the controller can assign different weights to the three exceedance values ​​and then perform a comprehensive weighted calculation to obtain a comprehensive gas entrapment index. The degree of gas entrapment is then determined based on the numerical range within which this comprehensive gas entrapment index falls. For example, considering that the temperature difference ΔT directly reflects the temperature difference between the liquid and gas phases and is perhaps the most direct parameter characterizing gas entrapment, it can be assigned a higher weight; the exceedance value of the heating rate, as an auxiliary judgment parameter, can be assigned a relatively lower weight. The specific weight allocation scheme and grading range of the weighted calculation can be determined based on the actual calibration results, and this application does not limit this.

[0089] In another alternative implementation, the controller can compare the three over-limit values ​​with their respective minor and severe thresholds, and use the highest level among the three over-limit values ​​as the final suffocation level. For example, if ΔT_over corresponds to a severe level, V1_over to a moderate level, and V2_over to a moderate level, then the highest level, severe, is taken as the final suffocation level. This approach helps to promptly trigger severe suffocation response measures when any dimension of the parameter shows a serious anomaly, reducing the underestimation of the severity of suffocation due to inconsistencies in the levels of parameters across different dimensions.

[0090] It should also be understood that the specific implementation method of determining the degree of gas entrapment based on the three exceeding limits can have various variations, and those skilled in the art can choose different grading rules according to actual needs. Regardless of the specific grading method adopted, the core is to quantitatively assess the severity of gas entrapment based on the degree of exceeding the temperature difference limit and the degree of exceeding the dual heating rate limit. These variations are all equivalent substitutions or simple modifications of the technical solution of this application.

[0091] After the controller determines the degree of air entrapment, it can output the air entrapment degree information as the determination result for use in subsequent fault recording, fault indication, or degassing control processes. This application does not limit the specific way the air entrapment degree information is used.

[0092] It is understood that although the embodiments of this application illustrate three levels (slight, moderate, and severe) as an example, in practical applications, the number of levels is not limited to three. For example, depending on the actual control accuracy requirements, the degree of entrapment can also be divided into two levels (entrapment present and severe entrapment) or four or more levels (such as very slight entrapment, slight entrapment, moderate entrapment, severe entrapment, and extremely severe entrapment). The selection of the number of levels can be determined according to the specific needs of the vehicle cooling system and the computing power of the controller, and this application does not impose specific limitations on this.

[0093] In one feasible implementation, the step of determining the degree of air entrapment in the pipeline is followed by: Based on the degree of air entrapment, a corresponding degassing scheme and fault indication scheme are adopted.

[0094] In some embodiments of this application, after determining the degree of air entrapment in the pipeline, as an optional implementation, a degassing scheme and a fault indication scheme corresponding to the determined degree of air entrapment can be adopted.

[0095] Since the amount of gas accumulated in the pipeline varies under different degrees of gas entrapment, the impact on the heat exchange efficiency, circulation resistance, and operational safety of the cooling system also varies. Therefore, adopting differentiated degassing schemes and fault indication schemes for different degrees of gas entrapment can help optimize the utilization of system resources while ensuring the exhaust effect.

[0096] Specifically, when the entrapment is mild, the amount of gas accumulated in the pipes is small, and the impact on the heat exchange efficiency and circulation resistance of the cooling system is minimal. In this case, a relatively low-intensity degassing scheme can be used. The fault indication scheme for mild entrapment can be to not issue a noticeable fault alarm, or simply record a fault log in the system background without notifying the driver or passengers, to reduce unnecessary alarms triggered by mild entrapment and avoid causing inconvenience. Alternatively, the fault indication scheme for mild entrapment can also be to display cooling system status information on the control panel in a non-alert manner (such as text prompts or constantly lit indicator lights), indicating that the system is performing routine venting maintenance.

[0097] When the air entrapment level is moderate, the amount of gas accumulated in the pipes has a noticeable impact on the cooling system. In this case, a moderately intensive degassing method is needed to effectively flush and remove the accumulated gas. The corresponding fault indication scheme for moderate air entrapment can be to display an air entrapment fault code or graphic prompt on the control panel (e.g., the dashboard) to remind drivers and passengers that the cooling system has an air entrapment fault and requires attention. Optionally, in the case of moderate air entrapment, monitoring can be continued for a period of time after degassing to confirm whether the air entrapment has been successfully eliminated; if the air entrapment is not eliminated after a preset number of degassing operations, a fault code can be continuously displayed on the control panel, prompting manual inspection.

[0098] When the entrapment is severe, a large amount of gas accumulates in the pipes, significantly reducing the heat exchange efficiency of the cooling system and posing a high risk of dry burning of components. In this case, the most intensive degassing method is required to quickly and thoroughly remove the accumulated gas. A fault indication scheme for severe entrapment can be to send an entrapment alarm to the control panel (e.g., flashing warning lights, audible alarms, or graphic warning messages) to clearly convey a serious malfunction in the cooling system to the driver and passengers. In one implementation, the fault indication scheme for severe entrapment can further include measures to limit vehicle power output to reduce the risk of the vehicle continuing to operate at high power when the cooling system's heat dissipation capacity is severely insufficient, thereby reducing the risk of overheating and damage to components. Furthermore, if the entrapment persists after a preset number of forced degassing operations in the case of severe entrapment, a forced maintenance prompt can be continuously displayed on the control panel, requiring immediate manual inspection.

[0099] It is understood that the degassing schemes and fault indication schemes corresponding to the above-mentioned mild, moderate and severe air entrapment are only illustrative examples. The specific degassing parameters (such as water pump speed, running time, upper limit of degassing times, etc.) and fault indication methods (such as indication content, indication form, indication duration, etc.) corresponding to each level can be adaptively set according to the actual structural characteristics of the cooling system, the vehicle control strategy and calibration results. This application does not make specific limitations in this regard.

[0100] It should also be understood that the correspondence between the degree of air entrapment and the degassing scheme and fault indication scheme is not limited to the one-to-one correspondence of "slight-low intensity scheme, moderate-medium intensity scheme, and severe-high intensity scheme" mentioned above. For example, in some embodiments, slight and moderate air entrapment can be combined into the same degassing scheme according to actual control needs, with only the indication scheme differing; in other embodiments, while using a high-intensity degassing scheme for severe air entrapment, subsequent strategies can be dynamically adjusted based on the monitoring results after degassing. For example, if the degree of air entrapment is reduced but not completely eliminated after the first degassing, a degassing scheme for moderate air entrapment can be downgraded for supplementary treatment. All of the above variations do not change the core technical concept of "adopting the corresponding degassing scheme and fault indication scheme according to the degree of air entrapment" and are all equivalent substitutions or simple modifications of the technical solution of this application.

[0101] In some implementations, the fault indication scheme can be executed by the vehicle thermal management controller sending corresponding prompt commands to the vehicle's instrument panel controller or central control screen controller. Upon receiving the prompt command, the instrument panel controller or central control screen controller displays corresponding text, icons, indicator lights, or sound prompts on the instrument panel or central control screen according to the command content. In other implementations, the fault indication scheme can also upload fault information to a cloud server or send it to user terminal devices (such as mobile apps) via the vehicle communication module for remote monitoring and maintenance reminders. This application does not limit the specific hardware implementation and presentation format of the fault indication.

[0102] In one feasible implementation, the step of adopting a corresponding degassing scheme and fault indication scheme based on the degree of air entrapment includes: When the degree of air entrapment is slight, the water pump is controlled to run at a first preset speed for a first preset duration to perform the first degassing operation.

[0103] In some embodiments of this application, after determining that the degree of air entrapment is slight, as an optional implementation, a first degassing operation can be performed according to the degassing scheme corresponding to slight air entrapment.

[0104] When the air entrapment level is slight, it indicates that the amount of gas accumulated in the pipeline is relatively small, and its impact on the heat exchange efficiency and circulation resistance of the cooling system is relatively limited. In response to this characteristic of slight air entrapment, the vehicle thermal management controller controls the water pump of the cooling system to run at a first preset speed for a first preset duration to flush the pipeline with a moderate water flow, thereby expelling the small amount of gas accumulated at high points or dead corners of the pipeline.

[0105] In one implementation, the controller sends a speed control command to the pump driver, which includes a target speed value (i.e., a first preset speed). Upon receiving the speed control command, the pump driver adjusts the current speed of the pump motor to the first preset speed and maintains this speed for a first preset duration. After the first preset duration ends, the controller sends a recovery command to the pump driver, restoring the pump speed to its normal operating speed.

[0106] Optionally, while controlling the water pump to run at a first preset speed for a first preset duration to perform the first degassing operation, the controller can also control the valves related to degassing in the cooling system (such as degassing valves or water valves) to switch to the opening state in degassing mode, so as to cooperate with the water flow of the water pump to achieve smooth gas discharge. After degassing is completed, the above valves can be restored to the opening state in normal operation mode.

[0107] The first preset speed can be set lower than the water pump speed corresponding to moderate and severe entrapment. Since the amount of gas is small in a mild entrapment state, high-intensity water flow is not required to expel the gas; therefore, the first preset speed can be set to a relatively low value. For example, in some embodiments, the first preset speed can be between 50% and 80% of the water pump's rated speed, or between 1.2 and 1.5 times the water pump speed under normal vehicle operating conditions. The specific value of the first preset speed can be determined based on the cooling system's piping structure, water pump performance parameters, and calibration results; this application does not impose specific limitations on this.

[0108] The first preset time should be shorter than the pump running time corresponding to moderate and severe air entrapment. Since the amount of gas to be expelled is small under mild air entrapment conditions, a shorter degassing time is sufficient to complete the venting task. For example, in some embodiments, the first preset time can be between 20 and 40 seconds. The specific value of the first preset time can be determined based on actual venting performance calibration, and this application does not impose a specific limitation on it.

[0109] In one implementation, after degassing is completed, the controller can continuously monitor the first and second temperature signals to confirm whether the trapped gas has been successfully removed. If the trapped gas is detected to have been removed, the cooling system can automatically reset to normal operation and monitoring mode, that is, the controller continues to acquire the two temperature signals at a preset acquisition frequency and perform real-time trapped gas determination. If the trapped gas is detected to still exist, the controller can re-execute the first degassing operation or upgrade the degassing scheme according to changes in the actual trapped gas state. The selection of parameters such as thresholds, speed, and duration under slight trapped gas conditions is designed to ensure basic exhaust effect and low energy consumption. Specific values ​​can be calibrated and verified through vehicle bench testing.

[0110] It should be understood that the specific values ​​of the first preset speed and the first preset duration can be adaptively adjusted according to different vehicle models, different cooling system layouts, and different operating conditions. For example, for cooling systems with longer pipelines or more complex structures, the first preset speed can be appropriately increased or the first preset duration extended; for cooling systems with shorter pipelines or simpler structures, the first preset speed can be appropriately decreased or the first preset duration shortened. Regardless of how the specific parameters are adjusted, any scheme that degassing under slight air entrapment conditions at a relatively low speed and a relatively short duration falls within the protection scope of this application's technical solution.

[0111] In one feasible implementation, the step of adopting a corresponding degassing scheme and fault indication scheme based on the degree of air entrapment includes: When the degree of air entrapment is moderate, the water pump is controlled to run at a second preset speed for a second preset duration to perform a second degassing operation. After the second degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the second degassing operation is repeated. After the second degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a trapped air fault prompt is issued.

[0112] In some embodiments of this application, after determining that the degree of air entrapment is moderate, as an optional implementation, the corresponding air removal control and fault indication control can be executed according to the air removal scheme and fault indication scheme corresponding to moderate air entrapment.

[0113] When the gas trapping level is moderate, it indicates that the amount of gas accumulated in the pipeline has reached a level that has a perceptible negative impact on the heat exchange efficiency and circulation resistance of the cooling system, and there is a certain risk of dry burning of components. In response to this characteristic of moderate gas trapping, the vehicle thermal management controller controls the water pump of the cooling system to run at a second preset speed for a second preset duration to strengthen the water flow flushing of the pipeline, thereby effectively expelling the large amount of gas accumulated at high points or dead corners of the pipeline.

[0114] Compared to the first preset speed used for slight air trapping, the second preset speed can be set to a higher speed value to generate a stronger water flow flushing force. The enhanced water flow flushing force helps overcome the adhesion of gas to the inner walls or dead corners of the pipes, stripping away the more accumulated gas from the pipes and pushing it to the exhaust port for discharge. Compared to the first preset duration used for slight air trapping, the second preset duration can be set to a longer running time to provide more sufficient venting time. The specific values ​​of the second preset speed and the second preset duration can be determined based on the cooling system's piping structure, water pump performance parameters, and actual vehicle calibration results; this application does not impose specific limitations on these. For example, in some embodiments, the second preset speed can be between 80% and 100% of the water pump's rated speed; the second preset duration can be between 40 and 90 seconds. In one implementation, the "second preset speed" in the second degassing operation can specifically be the water pump running at full speed (i.e., the water pump motor operating at its maximum permissible speed) to maximize the flushing effect of the water flow on the flow channel.

[0115] While controlling the water pump to run at a second preset speed for a second preset duration to perform the second degassing operation, the controller can also control the valves related to degassing in the cooling system (such as degassing valves or water valves) to switch to the corresponding opening state in the degassing mode to ensure that gas can be smoothly discharged from the exhaust port. Optionally, the controller can also monitor the operating status of the water pump in real time, such as monitoring whether the actual speed of the water pump reaches the second preset speed, whether the water pump running time reaches the second preset duration, etc., to ensure that the degassing process is executed according to the preset parameters.

[0116] After the second degassing operation is completed, the controller does not immediately stop monitoring for trapped gas. Instead, it continues to perform a trapped gas determination again based on the temperature signals collected by the first and second temperature sensors to determine whether the trapped gas in the pipeline has been eliminated after the second degassing operation. If the trapped gas is determined to be eliminated (i.e., the temperature difference ΔT does not exceed the preset temperature difference threshold, the first heating rate Vt1 does not exceed the first preset rate threshold, and the second heating rate Vt2 does not exceed the second preset rate threshold), it indicates that the second degassing operation has completed the exhaust task. The controller then controls the cooling system to automatically reset to normal operation and monitoring mode, continuing to acquire the two temperature signals at a preset acquisition frequency and perform trapped gas determination in real time.

[0117] If, after the second degassing operation, the first and second temperature signals indicate that air remains trapped in the pipeline, it means that the single second degassing operation failed to completely remove the accumulated gas from the pipeline. In this case, the controller controls the water pump to run again at the second preset speed for the second preset duration, repeating the second degassing operation. Through the cumulative effect of multiple degassing operations, each degassing operation further reduces the amount of residual gas in the pipeline based on the previous operation, thereby improving the thoroughness of air removal.

[0118] The controller counts the number of times the second degassing operation is repeated. If the number of repetitions of the second degassing operation has not reached the preset upper limit, monitoring continues after each degassing operation, and a decision is made based on the judgment result whether to perform degassing again. The specific value of the preset upper limit can be determined according to the structure of the cooling system and the degassing efficiency calibration. For example, in some embodiments, the preset upper limit can be 5 times. That is, during a single power-on period, the controller can repeat the second degassing operation a maximum of 5 times. Setting the preset upper limit can reduce energy waste and component wear caused by the water pump continuously running ineffectively when stubborn trapped air cannot be removed. In other embodiments, the preset upper limit can also be 3, 4, or 6 times, etc., and this application does not specifically limit this.

[0119] After the second degassing operation has been repeated a maximum of the preset number of times, if the first and second temperature signals indicate that trapped air still exists in the pipeline, it means that the stubborn trapped air in the pipeline cannot be effectively removed after multiple enhanced degassing operations. At this time, the controller issues a trapped air fault warning. The trapped air fault warning can be implemented in various forms. For example, the controller can send a fault warning command to the vehicle's instrument panel controller or central control screen controller. Upon receiving the command, the instrument panel controller or central control screen controller displays a trapped air fault code or graphic / textual warning information on the instrument panel or central control screen to inform the driver and passengers that the cooling system has a persistent trapped air fault that cannot be removed and requires manual inspection. Optionally, the fault warning information may include information about the location of the trapped air (e.g., the identification of the faulty pipeline), the severity of the trapped air, and suggested repair measures.

[0120] In one implementation, after issuing a entrapment fault warning, the controller can still maintain monitoring of the cooling system, continue to acquire the first and second temperature signals, and perform real-time entrapment determination so that the fault warning can be promptly identified and cleared after the entrapment resolves itself or is resolved manually. In another implementation, after reaching a preset limit on the number of attempts, the controller can store the fault information in non-volatile memory so that historical entrapment fault records can be retrieved the next time the vehicle is powered on or when maintenance personnel read the fault codes.

[0121] It should be understood that the specific values ​​of the aforementioned preset number of times upper limit, second preset speed, and second preset duration can be adaptively adjusted according to different vehicle models, different cooling system layouts, and different operating conditions. For example, for cooling systems with longer pipelines or more complex structures, the second preset speed can be appropriately increased or the second preset duration extended; for cooling systems with greater exhaust difficulty, the preset number of times upper limit can be appropriately increased. Regardless of how the specific parameters are adjusted, any solution that repeatedly performs degassing under moderate air entrapment conditions and issues a fault warning after reaching the maximum number of times falls within the protection scope of this application's technical solution.

[0122] It should also be understood that during the repeated execution of the second degassing operation, the duration for monitoring and determining whether trapped gas has been eliminated after each degassing operation can be set according to actual needs. For example, in some embodiments, monitoring can continue for 30 seconds after each degassing operation. If the temperature difference ΔT, the first heating rate Vt1, and the second heating rate Vt2 all recover to the normal threshold range within 30 seconds, the trapped gas is determined to be eliminated; if the parameters do not recover within 30 seconds, the trapped gas is determined to still exist. The monitoring duration should be long enough to reflect the stable state after degassing, and short enough to ensure timely response to changes in the trapped gas state. In other implementations, the monitoring duration can also be 15 seconds, 45 seconds, or 60 seconds, etc., and this application does not specifically limit this.

[0123] In one feasible implementation, the step of adopting a corresponding degassing scheme and fault indication scheme based on the degree of air entrapment includes: When the air entrapment level is severe, the water pump is controlled to run at a third preset speed for a third preset duration to perform a third degassing operation, and an air entrapment alarm is issued. After the third degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the third degassing operation is repeated. After the third degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a forced maintenance prompt will be issued and the vehicle's power output will be restricted.

[0124] In some embodiments of this application, after determining that the degree of air entrapment is severe, as an optional implementation, corresponding degassing control and fault indication control can be executed according to the degassing scheme and fault indication scheme corresponding to severe air entrapment.

[0125] When the gas entrapment level is severe, it indicates a large amount of gas accumulated in the pipeline, a significant decrease in the heat exchange efficiency of the cooling system, a high risk of dry burning of components, and potential issues such as localized overheating or abnormal water flow noise. To address the severity of severe gas entrapment, the vehicle's thermal management controller controls the cooling system's water pump to operate at a third preset speed for a third preset duration to flush the pipeline with high-intensity water flow, thereby quickly and thoroughly expelling the large amount of accumulated gas. Compared to the second preset speed used for moderate gas entrapment, the third preset speed can be set to a higher value to generate the strongest water flow flushing force; compared to the second preset duration used for moderate gas entrapment, the third preset duration can be set to a longer operating time to provide the most sufficient venting time.

[0126] In one implementation, the third preset speed can be the water pump running at full speed, i.e., the water pump motor operates at its maximum permissible speed to maximize the flushing effect of the water flow on the flow channel. The specific values ​​of the third preset speed and the third preset duration can be determined based on the cooling system's piping structure, water pump performance parameters, and actual vehicle calibration results; this application does not impose specific limitations on these. For example, in some embodiments, the third preset speed can be 100% of the water pump's rated speed (i.e., full speed); the third preset duration can be between 60 and 120 seconds. The controller sends a speed control command to the water pump driver, and upon receiving the command, the water pump driver adjusts the water pump motor speed to the third preset speed and maintains that speed for the third preset duration.

[0127] While controlling the water pump to operate at a third preset speed for a third preset duration to perform the third degassing operation, the controller also issues a entrapment alarm. Compared to the fault indication (displaying a fault code) for moderate entrapment, the alarm for severe entrapment is more alarming. In one implementation, the controller can send an alarm command to the vehicle's instrument panel controller or central control screen controller. Upon receiving the command, the instrument panel controller or central control screen controller will display the entrapment alarm on the instrument panel or central control screen through flashing warning lights, prominent graphic and text prompts, or audible alarms to clearly convey to the driver and passengers that there is a serious fault in the cooling system. In another implementation, the controller can also upload the severe entrapment alarm information to a cloud server or send it to user terminal devices (such as a mobile APP) via the vehicle communication module for remote monitoring and timely reminders.

[0128] Optionally, while controlling the water pump to run at a third preset speed for a third preset duration to perform the third degassing operation, the controller can also control the valves related to degassing in the cooling system (such as degassing valves or water valves) to switch to the maximum opening state in the degassing mode, so as to ensure that a large amount of gas can be smoothly and quickly discharged from the exhaust port.

[0129] After the third degassing operation is completed, the controller does not immediately stop the trapped gas monitoring. Instead, it continues to perform trapped gas determination again based on the temperature signals collected by the first and second temperature sensors to determine whether the severe trapped gas in the pipeline has been eliminated after the third degassing operation. If the trapped gas is determined to be eliminated (i.e., the temperature difference ΔT does not exceed the preset temperature difference threshold, the first heating rate Vt1 does not exceed the first preset rate threshold, and the second heating rate Vt2 does not exceed the second preset rate threshold), it indicates that the third degassing operation has completed the exhaust task. The controller controls the cooling system to automatically reset to normal operation and monitoring mode, and the trapped gas alarm prompt can be deactivated on the control panel. It continues to acquire the two temperature signals at the preset acquisition frequency and perform trapped gas determination in real time.

[0130] If, after the third degassing operation, the first and second temperature signals indicate that air remains trapped in the pipeline, it means that the single third degassing operation failed to completely remove the large amount of gas accumulated in the pipeline. In this case, the controller controls the water pump to run again at the third preset speed for the third preset duration, repeating the third degassing operation. Because the amount of gas accumulated under severe air entrapment is large, residual gas may still remain after a single high-intensity degassing operation. Through the cumulative effect of multiple high-intensity degassing operations, each degassing operation can further reduce the amount of residual gas in the pipeline based on the previous degassing operation, helping to gradually remove stubborn trapped gas.

[0131] The controller counts the number of times the third degassing operation is repeated. If the number of repetitions of the third degassing operation has not reached the preset limit, monitoring continues after each degassing operation, and a decision is made based on the judgment result whether to perform degassing again. After the number of repetitions of the third degassing operation reaches the preset limit, if it is determined from the first and second temperature signals that there is still trapped air in the pipeline, it indicates that the stubborn trapped air in the pipeline cannot be effectively removed after multiple high-intensity degassing operations. At this time, the controller issues a forced maintenance prompt and limits the vehicle's power output.

[0132] Forced maintenance prompts can be implemented using a stronger warning method than drowsy air entrapment alarms. In one implementation, the controller can send a forced maintenance command to the instrument cluster controller or central control screen controller, continuously displaying a forced maintenance prompt on the instrument cluster or central control screen (e.g., a graphic message saying "Please inspect the cooling system immediately" or a continuously flashing red warning light) to clearly convey the severity of the fault to the driver and passengers, indicating that "immediate manual maintenance is required." Even if the vehicle is powered off and then back on, the forced maintenance prompt will continue to be displayed to ensure that maintenance personnel can read the fault information.

[0133] Limiting vehicle power output can be achieved by the vehicle thermal management controller sending a power limiting request to the vehicle controller. Upon receiving the power limiting request, the vehicle controller can limit the maximum output torque of the drive motor or the maximum output power of the engine. This prevents the vehicle from operating at high power for extended periods when the cooling system suffers from severe entrapment or insufficient heat dissipation, thereby reducing the risk of component overheating and damage due to insufficient heat dissipation.

[0134] In one implementation, limiting vehicle power output may include limiting the vehicle's maximum speed to below a preset speed, such as limiting the maximum speed to 30 km / h or 40 km / h. In another implementation, limiting vehicle power output may include limiting the maximum output torque of the drive motor to 50% or less of the maximum torque under normal operating conditions. In yet another implementation, limiting vehicle power output may also include limiting the engine speed to below a preset speed to reduce the amount of heat generated by the engine under high speed and high load conditions that the cooling system cannot effectively dissipate. The specific strategies and parameters for power limiting can be calibrated according to vehicle type, powertrain configuration, and safety protection requirements; this application does not impose specific limitations on these aspects.

[0135] It should be understood that the specific values ​​of the preset maximum number of times, the third preset speed, and the third preset duration can be adaptively adjusted according to different vehicle models, different cooling system layouts, and different operating conditions. For example, the preset maximum number of times can be 5 times, meaning that the third degassing operation can be repeated a maximum of 5 times during a single power-on period. Setting the preset maximum number of times can reduce energy waste and component wear caused by the water pump continuously running ineffectively when stubborn trapped air cannot be removed. If the trapped air is still not removed after reaching the preset maximum number of times, it indicates that manual intervention is required for maintenance, and continuing automatic degassing has limited value.

[0136] It should also be understood that during the repeated execution of the third degassing operation, the duration for monitoring and determining whether trapped gas has been eliminated after each degassing operation can be set according to actual needs. For example, in some embodiments, monitoring can continue for 30 seconds after each degassing operation. If the temperature difference ΔT, the first heating rate Vt1, and the second heating rate Vt2 all return to the normal threshold range within 30 seconds, the trapped gas is determined to be eliminated; if the parameters do not return within 30 seconds, the trapped gas is determined to still exist. The monitoring duration should be set long enough to reflect the stable state after degassing, and short enough to ensure timely response to changes in the trapped gas state.

[0137] It should also be understood that the aforementioned mandatory maintenance prompts and power limiting measures under severe air entrapment can be executed simultaneously after reaching the preset limit of times, or, depending on the actual control strategy, the mandatory maintenance prompt can be executed first, and if no manual intervention signal (such as a maintenance mode activation signal or a fault reset signal) is received within a preset time after the prompt, the power limiting measures can then be further executed. Regardless of the specific execution sequence, any scheme that issues mandatory maintenance prompts and limits vehicle power output when repeated degassing fails to eliminate severe air entrapment falls within the protection scope of this application's technical solution.

[0138] This application also provides a pipeline gas entrapment detection system, the pipeline gas entrapment detection system comprising: The water temperature detection module includes a first temperature sensor and a second temperature sensor integrated in the same water temperature sensor assembly; the first temperature sensor is used to detect a first temperature signal characterizing the temperature of the liquid phase in the pipeline, and the second temperature sensor is used to detect a second temperature signal characterizing the temperature of the gas phase or gas-liquid mixture in the pipeline. The control module is electrically connected to the first temperature sensor and the second temperature sensor respectively. The control module is used to determine whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal, and to execute the corresponding degassing control strategy and / or fault indication strategy according to the degree of trapped air.

[0139] The following is combined Figure 3 The pipeline gas trapping detection system provided in the embodiments of this application will be described in detail.

[0140] Figure 3 This is a schematic diagram of the architecture of an optional pipeline gas trap detection system provided in an embodiment of this application. Figure 3 As shown, the pipeline air entrapment detection system includes a water temperature detection module and a control module.

[0141] The water temperature detection module includes a first temperature sensor and a second temperature sensor integrated within the same water temperature sensor assembly. The first temperature sensor detects a first temperature signal characterizing the temperature of the liquid phase within the pipeline, and the second temperature sensor detects a second temperature signal characterizing the temperature of the gas phase or gas-liquid mixture within the pipeline. The two temperature sensors are arranged at the same cross-section of the pipeline flow channel, with the sensing end of the first temperature sensor located at or slightly below the centerline of the flow channel, and the sensing end of the second temperature sensor located near the upper surface of the flow channel. The structure and arrangement of the water temperature detection module have been described in detail in the above embodiments and will not be repeated here.

[0142] like Figure 3As shown, the control module is electrically connected to both the first and second temperature sensors. The control module includes a signal acquisition unit and a processor. The signal acquisition unit is connected to the signal output terminals of the first and second temperature sensors via signal harnesses, and is used to receive the first temperature signal transmitted by the first temperature sensor and the second temperature signal transmitted by the second temperature sensor. The signal acquisition unit may include an analog-to-digital converter (ADC) to convert the analog electrical signals output by the temperature sensors into digital temperature values, so that the processor can perform subsequent digital signal processing and logical operations.

[0143] The processor determines whether trapped air exists in the pipeline based on a first temperature signal and a second temperature signal, and executes corresponding degassing control strategies and / or fault indication strategies according to the degree of trapped air. The processor may include one or more microcontrollers, digital signal processors, field-programmable gate arrays, or application-specific integrated circuits (ASICs). The processor executes computer program instructions stored in internal or external memory to implement the computational and control logic for trapped air detection, trapped air degree classification, and degassing control and fault indication strategies.

[0144] The control module also includes a memory. The memory is electrically connected to the processor and is used to store various preset parameters, such as a preset temperature difference threshold, a first preset rate threshold, a second preset rate threshold, a preset maximum number of operations, a first preset rotational speed, a first preset duration, a second preset rotational speed, a second preset duration, a third preset rotational speed, and a third preset duration, as well as intermediate data and final judgment results generated by the processor during operation. The memory may include non-volatile memory and volatile memory.

[0145] The control module also includes a control output unit. The control output unit is electrically connected to the processor and is used to send corresponding control signals to external execution devices based on the degassing control commands and / or fault indication commands generated by the processor. The control output unit can be electrically connected to the water pump driver of the cooling system through its control output port to send speed control commands to the water pump driver, controlling the water pump to run at a preset speed for a preset duration, thus implementing degassing schemes corresponding to different levels of air entrapment. For example, in cases of slight air entrapment, the control output unit sends a speed control command containing a first preset speed to the water pump driver and maintains this command for a first preset duration; in cases of moderate air entrapment, it sends a speed control command containing a second preset speed and maintains this command for a second preset duration; in cases of severe air entrapment, it sends a speed control command containing a third preset speed and maintains this command for a third preset duration. The control output unit can also be electrically connected to the valve driver of the cooling system to synchronously send valve control commands to the valve driver when executing the degassing control strategy, controlling the valves related to degassing to switch to the opening state in the degassing mode.

[0146] The control output unit can also communicate with the vehicle's instrument cluster controller or central control screen controller via its communication port. This allows it to send corresponding prompts to the instrument cluster controller or central control screen controller, displaying corresponding text, icons, indicator lights, or sound prompts on the instrument panel or central control display screen. For example, in cases of mild entrapment, the control output unit can send a background recording command to record only the fault log without displaying any prompts. In cases of moderate entrapment, it sends a fault code display command to display the entrapment fault code on the control panel. In cases of severe entrapment, it sends an alarm display command to display an entrapment alarm on the control panel, and after reaching a preset limit for the number of entrapments, it sends a forced maintenance prompt command.

[0147] In one implementation, the control output unit can also communicate with the vehicle controller via an onboard communication module. After the number of severe entrapment attempts reaches a preset limit, the control output unit sends a power limiting request command to the vehicle controller. Upon receiving this command, the vehicle controller limits the maximum output torque of the drive motor or the maximum output power of the engine to reduce the risk of overheating and damage to components due to insufficient heat dissipation.

[0148] The control module and the water temperature detection module, as well as the control module and various external devices, can be connected by wired means or by vehicle network. This application does not limit the connection in this regard.

[0149] In one implementation, the control module can be a vehicle thermal management controller, i.e., the central controller of the vehicle thermal management system, which integrates a signal acquisition unit, a processor, a memory, and a control output unit. The vehicle thermal management controller is electrically connected to the first temperature sensor and the second temperature sensor through its signal acquisition port, and is electrically or communicatively connected to external devices such as the water pump driver, the instrument controller, and the vehicle controller through its control output port.

[0150] In another implementation, the control module can be a standalone trapped air detection and control unit. This control unit is independent of the vehicle's thermal management controller and communicates with it via the vehicle's network. The trapped air detection and control unit is responsible for performing calculations such as trapped air detection and trapped air severity classification, transmitting the classification results to the vehicle's thermal management controller. The vehicle's thermal management controller then executes corresponding degassing control and fault indication control based on the classification results. By separating the detection and calculation functions from the control execution functions, the system's modularity can be improved, facilitating system maintenance and upgrades.

[0151] In another implementation, the functions of the control module can be performed collaboratively by multiple controllers. For example, signal acquisition and filtering preprocessing are performed by a signal acquisition unit (which can be an independent sub-controller), entrapment determination and grading logic are performed by a processor (which can be a main controller), and degassing control and fault indication are performed by a control output unit (which can be another execution controller). Multiple controllers interact with each other via an in-vehicle network. The specific physical implementation of the control module can be flexibly selected based on the vehicle's electronic and electrical architecture design.

[0152] Optionally, the control module may also include a power management unit for providing a stable operating voltage to the various units within the control module and for maintaining the fault information stored in the memory after the vehicle is powered off.

[0153] Understandable Figure 3 The diagram shows only one exemplary architecture for a pipeline air trap detection system, and the connection relationships and specific components between the modules are not limited to those shown. For example, the control module and the instrument controller may not be directly connected, but may communicate indirectly through the vehicle's CAN bus; furthermore, the control module may include additional filtering circuits and signal conditioning circuits to improve the quality of temperature signal acquisition. All of the above modifications do not affect the implementation of the technical solution of this application and are all within the protection scope of this application.

[0154] The pipeline gas trapping detection system provided in this application embodiment, through the integrated dual temperature sensor assembly and the detection and control logic of the control module, can achieve accurate detection and graded processing of trapped gas without the need to add pressure sensors or flow sensors. It has the advantages of simple structure, low cost, high detection accuracy, timely response and strong adaptability of control strategy.

[0155] This application also provides a vehicle that includes the pipeline gas trap detection system as described above.

[0156] In some embodiments of this application, a vehicle is provided that includes the pipeline air entrapment detection system described in any of the above embodiments. The specific structure, components, and functions of the pipeline air entrapment detection system have been described in detail in the above system embodiments and will not be repeated here.

[0157] The vehicle also includes a coolant circulation loop. This loop contains coolant lines through which coolant circulates to dissipate heat or regulate the temperature of the vehicle's powertrain or thermal management components. The powertrain may include an engine and / or a drive motor, while thermal management components may include a battery pack and / or a heater core. After flowing through the components, the coolant returns to the radiator for cooling, and is then pumped out by a water pump to continue its circulation.

[0158] The water temperature detection module of the pipeline air trapping detection system is installed on the pipeline of the coolant circulation loop. Specifically, the integrated dual temperature sensor assembly in the water temperature detection module is installed at locations in the pipeline prone to air trapping. Locations prone to air trapping refer to relatively high positions in the pipeline where air easily accumulates and becomes trapped, such as the highest point of an inverted U-shaped pipeline structure, the upper side of a pipeline bend, near the inlet and outlet of the heat exchanger cavity, or the water inlet pipe of the heater core. By placing the water temperature detection module at these locations, the second temperature sensor can promptly contact the accumulated gas when air trapping occurs, thereby accurately detecting the temperature of the gas phase or gas-liquid mixture.

[0159] In one implementation, the water temperature detection module can be located at the water inlet pipe of the heater core. The heater core is typically located in the vehicle's passenger compartment, a relatively high position with a complex internal cavity structure, making it a typical location where air entrapment can easily occur in the cooling system. By installing an integrated dual-temperature sensor assembly at this location, the reduced heat exchange efficiency of the heater core due to air entrapment can be detected in a timely manner, ensuring the heating performance of the vehicle's passenger compartment.

[0160] In another implementation, the water temperature detection module can be located at the outlet pipe of the engine block water jacket. The internal structure of the engine block water jacket is complex, and gas can easily accumulate in the upper part of the water jacket during coolant filling or operation. When this gas flows with the coolant to the cylinder block outlet pipe, it can be effectively detected by the dual temperature sensor assembly located there.

[0161] In another implementation, the water temperature detection module can also be placed at the inlet or outlet pipe of the vehicle radiator. The radiator is usually located at the front of the vehicle and has multiple flat tubes and cooling fins inside. Gas can easily accumulate in the upper or lower water chamber of the radiator. Placing a water temperature detection module at this location can help to detect trapped gas in the radiator in a timely manner.

[0162] The vehicle also includes a thermal management controller. The thermal management controller is electrically connected to the first and second temperature sensors in the water temperature detection module, respectively, and is used to receive the two temperature signals and perform processing such as air entrapment detection, air entrapment severity classification, air removal control, and fault indication. The specific structure, components, and functions of the thermal management controller have been described in detail in the above system embodiments.

[0163] The vehicle also includes a water pump. The water pump is located in the coolant circulation loop and drives the coolant to circulate within the pipes. The water pump is electrically connected to a thermal management controller. After determining the degree of trapped air, the thermal management controller sends a corresponding speed control command to the water pump to control it to operate at different preset speeds and for preset durations, thus implementing degassing solutions corresponding to different degrees of trapped air.

[0164] The vehicle also includes a control panel. Located within the vehicle's cabin, such as the dashboard area, the control panel displays vehicle operating status information and fault warnings to the driver and passengers. The control panel may include an instrument panel, a central display screen, or a head-up display. The control panel communicates with the thermal management controller. When a fault warning or alarm is required, the thermal management controller sends a corresponding warning command to the control panel, which then displays appropriate text, icons, indicator lights, or sound prompts on the display screen based on the command.

[0165] The vehicle also includes a vehicle controller. The vehicle controller is communicatively connected to the thermal management controller and receives power limiting requests from the thermal management controller. Upon receiving such a request, the vehicle controller limits the vehicle's power output. For example, after a preset maximum number of severe entrapment attempts have been completed, the thermal management controller sends a power limiting request to the vehicle controller. Based on this request, the vehicle controller limits the maximum output torque of the drive motor or the maximum output power of the engine to reduce the risk of overheating and damage to components caused by the vehicle operating at high power when the cooling system's heat dissipation capacity is severely insufficient.

[0166] Optionally, the vehicle may also include a degassing valve. The degassing valve is located at the exhaust port of the coolant circulation loop and is electrically connected to the thermal management controller. When the thermal management controller executes the degassing control strategy, it simultaneously controls the degassing valve to switch to the open state, so that the water flow from the water pump can flush out the gas in the pipeline through the exhaust port. After degassing is complete, the thermal management controller controls the degassing valve to return to the closed state.

[0167] It should be understood that the specific placement of the aforementioned water temperature detection module in the vehicle can be adaptively selected based on the piping structure of the cooling system and the distribution of air entrapment points. For example, for a cooling system with multiple air entrapment points, water temperature detection modules can be installed at each of these points, and the thermal management controller can collect and judge the temperature signals from each path to accurately pinpoint the location where air entrapment occurs. Regardless of the location of the water temperature detection module in the cooling system, as long as its first temperature sensor can detect the liquid phase temperature and its second temperature sensor can detect the gas phase or gas-liquid mixture temperature when air entrapment is present, it falls within the protection scope of this application's technical solution.

[0168] It should also be understood that other components such as expansion tanks, thermostats, and electronic valves may be installed in the vehicle's coolant circulation loop. The thermal management controller and the vehicle controller can communicate via in-vehicle networks such as CAN bus, LIN bus, or FlexRay bus. All of the above modifications do not affect the implementation of the technical solution of this application and are all within the protection scope of this application.

[0169] The vehicle provided in this application embodiment, by being equipped with the above-mentioned pipeline trapped air detection system, can monitor the trapped air status in the cooling pipeline in real time during vehicle operation. It can achieve accurate detection and graded treatment of trapped air without the need to add pressure sensors or flow sensors, which helps to improve the operational stability, heat exchange efficiency and reliability of the vehicle cooling system.

[0170] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the pipeline gas trap detection method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0171] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for detecting trapped air in a pipeline, characterized in that, The pipeline gas trap detection method includes: A first temperature signal, used to characterize the temperature of the liquid phase inside the pipeline, is detected by a first temperature sensor. A second temperature signal, used to characterize the temperature of the gas phase or gas-liquid mixture within the pipeline, is detected by a second temperature sensor. Based on the first temperature signal and the second temperature signal, determine whether there is trapped air in the pipeline.

2. The pipeline gas trapping detection method as described in claim 1, characterized in that, The first temperature sensor and the second temperature sensor are integrated in the same water temperature sensor assembly and are arranged at the same flow channel cross section of the pipeline.

3. The pipeline gas trapping detection method as described in claim 1, characterized in that, The step of determining whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal includes: Determine the temperature difference between the first temperature signal and the second temperature signal, the first heating rate of the first temperature signal, and the second heating rate of the second temperature signal; When the temperature difference is greater than a preset temperature difference threshold, the first heating rate is greater than a first preset rate threshold, and the second heating rate is greater than a second preset rate threshold, it is determined that there is trapped air in the pipeline.

4. The pipeline gas trapping detection method as described in claim 3, characterized in that, Following the step of determining that air is trapped in the pipeline, the following is included: Determine the excess difference between the temperature difference and the preset temperature difference threshold, the first excess rate between the first heating rate and the first preset rate threshold, and the second excess rate between the second heating rate and the second preset rate threshold; The degree of air entrapment in the pipeline is determined based on the over-limit difference, the first over-limit rate value, and the second over-limit rate value. The degree of air entrapment includes slight air entrapment, moderate air entrapment, and severe air entrapment.

5. The pipeline gas trapping detection method as described in claim 4, characterized in that, The step of determining the degree of air entrapment in the pipeline is followed by: Based on the degree of air entrapment, a corresponding degassing scheme and fault indication scheme are adopted.

6. The pipeline gas trapping detection method as described in claim 5, characterized in that, The steps of adopting corresponding degassing schemes and fault indication schemes based on the degree of air entrapment include: When the degree of air entrapment is slight, the water pump is controlled to run at a first preset speed for a first preset duration to perform the first degassing operation.

7. The pipeline gas trapping detection method as described in claim 5, characterized in that, The steps of adopting corresponding degassing schemes and fault indication schemes based on the degree of air entrapment include: When the degree of air entrapment is moderate, the water pump is controlled to run at a second preset speed for a second preset duration to perform a second degassing operation. After the second degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the second degassing operation is repeated. After the second degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a trapped air fault prompt is issued.

8. The pipeline gas trapping detection method as described in claim 5, characterized in that, The steps of adopting corresponding degassing schemes and fault indication schemes based on the degree of air entrapment include: When the air entrapment level is severe, the water pump is controlled to run at a third preset speed for a third preset duration to perform a third degassing operation, and an air entrapment alarm is issued. After the third degassing operation is completed, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, the third degassing operation is repeated. After the third degassing operation has been repeated a maximum of a preset number of times, if it is determined from the first temperature signal and the second temperature signal that there is still trapped air in the pipeline, a forced maintenance prompt will be issued and the vehicle's power output will be restricted.

9. A pipeline gas trap detection system, characterized in that, The pipeline gas trap detection system includes: The water temperature detection module includes a first temperature sensor and a second temperature sensor integrated in the same water temperature sensor assembly; the first temperature sensor is used to detect a first temperature signal characterizing the temperature of the liquid phase in the pipeline, and the second temperature sensor is used to detect a second temperature signal characterizing the temperature of the gas phase or gas-liquid mixture in the pipeline. The control module is electrically connected to the first temperature sensor and the second temperature sensor respectively. The control module is used to determine whether there is trapped air in the pipeline based on the first temperature signal and the second temperature signal, and to execute the corresponding degassing control strategy and / or fault indication strategy according to the degree of trapped air.

10. A vehicle, characterized in that, The vehicle includes the pipeline entrapment detection system as described in claim 9.

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