Engine cooling system and fault detection method

Abstract

The application relates to an engine cooling system and a fault detection method, which comprises an engine, a heat exchanger, a sensor and a controller, the heat exchanger is connected with the engine in series through a pipeline, the sensor is connected with the engine and is used for collecting and sending an actual outlet water temperature value of the engine, the controller is connected with the sensor and is used for receiving the actual outlet water temperature value of the engine, and the controller is further used for determining a working condition mode of the outlet water temperature according to a comparison result of the actual outlet water temperature value and an outlet water temperature target value, so as to confirm a fault component in the engine and the heat exchanger.In the application, when the engine is running, the actual outlet water temperature value of the engine is compared with the outlet water temperature target value, so as to determine the working condition mode of the outlet water temperature, and different situations of the engine cooling system are analyzed, the risks or faults existing in the engine and the heat exchanger can be judged, and the engine can be prevented from being damaged to a greater extent due to the faults of the components of the engine cooling system.

Description

Technical Field

[0001] This application relates to the field of engine cooling technology, and in particular to an engine cooling system and a fault detection method. Background Technology

[0002] Existing engine cooling systems mainly consist of a water pump, thermostat, and heat exchanger. When the system is working, the water pump drives the coolant to flow within the engine water jacket, carrying away heat from the engine. At the same time, the external cooling system (such as a fan system) exchanges heat with the high-temperature coolant coming from the engine at the heat exchanger, lowering the coolant temperature. Then, driven by the engine water pump, the coolant re-enters the engine water jacket to cool the engine.

[0003] Existing engine cooling systems primarily use outlet water temperature as the control target, controlling engine cooling by adjusting the flow rate of the cooling medium outside the heat exchanger (for air-cooled systems). When diagnosing engine cooling system faults, only the overall engine cooling system is assessed, without combining it with individual components for detailed fault analysis or identifying the faulty component. Summary of the Invention

[0004] This application provides an engine cooling system and a fault detection method, which can solve the problem that the fault judgment methods of engine cooling systems in the related art only make a judgment on the engine cooling system as a whole, but do not combine detailed fault analysis of components, nor do they identify the faulty components.

[0005] In a first aspect, embodiments of this application provide an engine cooling system, comprising: an engine, a heat exchanger, a sensor, and a controller. The heat exchanger is connected in series with the engine via a pipeline. The sensor is connected to the engine and is used to collect and transmit the actual outlet water temperature value of the engine. The controller is connected to the sensor and is used to receive the actual outlet water temperature value of the engine. The controller is also used to determine the operating mode of the outlet water temperature based on the comparison result between the actual outlet water temperature value and the target outlet water temperature value, so as to identify faulty components in the engine and the heat exchanger.

[0006] In some embodiments, the operating mode of the outlet water temperature includes: a first operating mode, a second operating mode, and a third operating mode; the first operating mode is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature value; the second operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the outlet water temperature rise rate of the engine is greater than or equal to a first threshold; the third operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the outlet water temperature rise rate of the engine is greater than or equal to a second preset value and less than the first threshold value.

[0007] In some embodiments, the engine includes a thermostat; when the outlet water temperature is at a first operating condition, the controller is further configured to control the engine speed and load, and to confirm whether the thermostat is stuck; when the outlet water temperature is at a second operating condition, the controller is further configured to determine whether there is coolant in the engine cooling system based on the current change in engine outlet water temperature; when the outlet water temperature is at a third operating condition, the controller is further configured to determine whether the heat exchanger is blocked based on the current change in engine outlet water temperature.

[0008] In some embodiments, the engine further includes an engine water pump, and the thermostat and the engine water pump are connected in series on the pipeline along the coolant flow direction; the sensor is also used to collect and send the actual outlet water pressure value of the engine, and when the outlet water temperature is the second operating condition, the controller is also used to determine whether the engine water pump is faulty based on the comparison result between the actual outlet water pressure value and the outlet water pressure target value.

[0009] In some embodiments, the engine cooling system further includes a safety alarm connected to a controller, the safety alarm being used to issue an alarm notification based on the confirmation result of the controller.

[0010] In some embodiments, the sensor includes an engine outlet coolant temperature sensor disposed on a pipeline.

[0011] Secondly, embodiments of this application provide a fault detection method for an engine cooling system, comprising: acquiring the actual outlet water temperature value of the engine; comparing the actual outlet water temperature value of the engine with the target outlet water temperature value of the engine; confirming the current operating mode of the engine outlet water temperature based on the comparison result; and determining the faulty components in the engine and heat exchanger based on the current operating mode of the engine outlet water temperature.

[0012] In some embodiments, the engine includes a thermostat, and the operating modes of the outlet water temperature include: a first operating mode, a second operating mode, and a third operating mode; the first operating mode is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature value; the second operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the outlet water temperature rise rate of the engine is greater than or equal to a first threshold; the third operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the outlet water temperature rise rate of the engine is greater than or equal to a second threshold and less than a first threshold.

[0013] In some embodiments, based on the current engine outlet water temperature operating mode, the faulty components in the engine and heat exchanger are determined. Specific steps include: when the outlet water temperature is in the first operating condition, controlling the engine speed and load, and determining whether the thermostat is stuck based on the current engine outlet water temperature change; when the outlet water temperature is in the second operating condition, determining whether the engine cooling system has coolant based on the current engine outlet water temperature change; and when the outlet water temperature is in the third operating condition, determining whether the heat exchanger is blocked based on the current engine outlet water temperature change.

[0014] In some embodiments, the determination of whether there is coolant in the engine cooling system is based on the current change in engine outlet water temperature. The specific steps include: when the engine outlet water temperature rise rate is greater than or equal to a first threshold and the engine outlet water temperature exceeds the set range of the outlet water temperature target value, it is determined that there is no coolant in the engine cooling system. The absence of coolant in the engine cooling system includes a first fault condition, a second fault condition, and a third fault condition. When the engine cooling system is in the first fault condition, the engine cooling system lacks coolant. When the engine cooling system is in the second fault condition, the engine water pump is faulty. When the engine cooling system is in the third fault condition, the thermostat cannot open.

[0015] Based on the current changes in engine outlet water temperature, the process of determining whether the heat exchanger is blocked includes the following steps: if the engine outlet water temperature rise rate is greater than or equal to the second threshold and less than the first threshold, then the heat exchanger is determined to be blocked.

[0016] The beneficial effects of the technical solutions provided in this application include:

[0017] This application provides an engine cooling system and a fault detection method. When the engine is running, the actual outlet water temperature value of the engine is compared with the target outlet water temperature value to determine the operating mode of the outlet water temperature. Then, different situations of the engine cooling system can be analyzed to determine the risks or faults existing in the engine and heat exchanger, and prevent greater damage to the engine caused by the failure of engine cooling system components. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an engine cooling system provided in an embodiment of this application.

[0020] In the diagram: 1. Engine water pump; 2. Engine water jacket; 3. Engine outlet water temperature sensor; 4. Engine outlet water pressure sensor; 5. Heat exchanger; 6. Engine inlet water pressure sensor; 7. Engine inlet water temperature sensor; 8. Engine ECU; 9. Safety alarm; 10. First node; 11. Second node; 12. Piping; 13. Thermostat. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0022] This application provides an engine cooling system and a fault detection method, which can solve the problem that the engine cooling system fault judgment method in the related art only judges the engine cooling system as a whole, but does not combine the detailed fault analysis of components, nor does it confirm the faulty component.

[0023] The existing engine cooling system mainly consists of a water pump, thermostat 13, heat exchanger 5, etc. When the system is working, the water pump drives the coolant to flow in the engine water jacket 2 and carries away the engine heat; at the same time, the external cooling system (such as the fan system) exchanges heat with the high-temperature coolant coming from the engine on the heat exchanger 5, so that the coolant temperature is reduced, and then it enters the engine water jacket 2 again under the drive of the engine water pump 1 for engine cooling.

[0024] The existing engine cooling system mainly uses the outlet water temperature as the control target and controls engine cooling by adjusting the flow rate of the cooling medium outside the heat exchanger 5 (for air-cooled systems). When diagnosing engine cooling system faults, only the overall engine cooling system is judged, but the fault analysis is not combined with the components, and the faulty components are not identified.

[0025] The current methods for diagnosing engine cooling system faults only assess the overall system without analyzing individual components or identifying the faulty parts. In a first aspect, this application provides an engine cooling system comprising: an engine, a heat exchanger 5, a sensor, and a controller. The heat exchanger 5 is connected in series with the engine via a pipe 12. The sensor is connected to the engine and is used to collect and transmit the actual outlet water temperature value of the engine. The controller is connected to the sensor and is used to receive the actual outlet water temperature value of the engine. The controller is also used to determine the operating mode of the outlet water temperature based on a comparison between the actual outlet water temperature value and a target outlet water temperature value, in order to identify the faulty components in the engine and the heat exchanger 5.

[0026] When an engine is running, the high-temperature gases produced by combustion in the cylinders cause the temperature of critical components such as the cylinder head and pistons to rise. The cooling system's main function is to dissipate the engine's heat in a timely manner, keeping the temperature of various components and critical parts within the design range to ensure engine performance and reliability.

[0027] Currently, engine cooling system malfunctions are primarily judged based on outlet water temperature; if it cannot be controlled within the target value, a cooling system malfunction is diagnosed. However, the cooling system consists of multiple components, each with different functions, resulting in varying manifestations and degrees of impact from malfunctions. To achieve rapid identification of faulty components in the cooling system, or to conduct real-time inspections of each component's status and make early judgments in the initial stages of component abnormalities, thus preventing serious damage to the cooling system or engine, a dedicated testing method needs to be developed to track and inspect the cooling system and its components in real time. The inspection process can proceed item by item according to a specific logic.

[0028] In this application, the heat exchanger 5 is connected in series with the engine via pipe 12. That is, the engine outlet is connected to the heat exchanger 5 inlet via pipe 12, and the heat exchanger 5 outlet is connected to the engine inlet. Therefore, the liquid flows through the engine and heat exchanger 5 and then back to the engine, forming a liquid circulation loop. A first node 10 and a second node 11 are provided on pipe 12, and sensors are installed at both nodes. These sensors at different locations can collect the liquid temperature values ​​at different points on pipe 12. In this application, the liquid temperature values ​​include the actual outlet water temperature of the engine.

[0029] When the engine is running, the actual outlet water temperature value of the engine is compared with the target outlet water temperature value to determine the operating mode of the outlet water temperature. Then, the different situations of the engine cooling system can be analyzed to determine the risks or faults of the engine and heat exchanger 5, and prevent greater damage to the engine caused by the failure of the engine cooling system components.

[0030] In this application, the engine includes an engine water pump 1, an engine water jacket 2, and a thermostat 13. Along the coolant flow direction, the engine water pump 1, engine water jacket 2, and thermostat 13 are connected in series on the pipe 12. The engine water pump 1 provides the driving force for the flow of coolant in the cooling system, driving the coolant to circulate within the engine cooling system. The engine water jacket 2 serves as a coolant flow channel for heat exchange between the engine components and the coolant. The heat exchanger 5 is a key component of the engine cooling system, having a cavity structure. After the engine coolant is cooled within this cavity, it passes through the engine water pump 1 again before entering the engine water jacket 2 for engine cooling.

[0031] The sensors mentioned above include: engine outlet water temperature sensor 3, engine outlet water pressure sensor 4, engine inlet water temperature sensor 7, and engine inlet water pressure sensor 6, wherein the engine outlet water temperature sensor 3, engine outlet water pressure sensor 4, engine inlet water temperature sensor 7, and engine inlet water pressure sensor 6 are all installed on the pipeline 12. More specifically, the engine outlet water temperature sensor 3 and the engine outlet water pressure sensor 4 are installed at the second node 11, which is located between the engine water jacket 2 and the heat exchanger 5; the engine inlet water temperature sensor 7 and the engine inlet water pressure sensor 6 are installed at the first node 10, which is located between the heat exchanger 5 and the engine water pump 1.

[0032] Engine inlet water temperature sensor 7 is used to collect the engine inlet water temperature, or the engine inlet water temperature; engine inlet water pressure sensor 6 is used to collect the engine cooling system inlet water pressure, or the engine inlet water pressure, or even the engine water pump 1 inlet water pressure; engine outlet water temperature sensor 3 is used to collect the engine cooling system outlet water temperature, or the engine outlet water temperature; engine outlet water pressure sensor 4 is used to collect the engine cooling system outlet water pressure, or the engine outlet water pressure.

[0033] Meanwhile, the controller, namely the engine ECU8, is the engine control component. It is used to collect the actual inlet water pressure, outlet water pressure, inlet water temperature and outlet water temperature of the engine, and control the operation of each regulating valve according to the set control logic.

[0034] Based on the above embodiments, in this embodiment, the operating modes of the outlet water temperature include: a first operating mode, a second operating mode, and a third operating mode. In the first, second, and third operating modes, the actual outlet water temperature of the engine is compared with a preset target outlet water temperature value, which refers to the outlet water temperature value when the engine performs optimally. That is, the actual outlet water temperature of the engine is used as a working parameter of the cooling system. The actual outlet water temperature of the engine typically has two states: "high" and "low." Here, "high" outlet water temperature means that the actual outlet water temperature value of the engine is greater than the target outlet water temperature value; "low" outlet water temperature means that the actual outlet water temperature value of the engine is less than or equal to the target outlet water temperature value. The "high" and "low" states are also related to the deviation between the actual outlet water temperature and the target outlet water temperature value. Typically, the control accuracy of the target outlet water temperature value (control accuracy means that the deviation between the actual outlet water temperature and the target outlet water temperature value is within the required range) is ±2℃. If the target outlet water temperature is 88℃, then an actual outlet water temperature between 86℃ and 90℃ is acceptable. If the actual outlet water temperature exceeds 90℃, it is considered high; if it falls below 86℃, it is considered low. Then, considering the structure and characteristics of each component, analyze how a fault might affect the engine outlet water temperature. Specifically:

[0035] The first operating condition is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature. When the outlet water temperature is in the first operating condition, the controller is also used to control the engine speed and load, and to confirm whether the thermostat 13 has a stuck fault: Specifically, when the actual outlet water temperature of the engine is abnormal, and the actual outlet water temperature value of the engine is less than or equal to the target outlet water temperature value, the engine speed is fixed, and the engine load is adjusted from 100% to 50%. At this time, the engine outlet water temperature sensor 3 continues to collect the actual outlet water temperature of the engine. If, with the engine speed fixed and the engine load adjusted from 100% to 50%, the engine outlet water temperature first decreases rapidly and then slowly rises to near the target outlet water temperature value, then the thermostat 13 is working normally; if the engine outlet water temperature first decreases rapidly to below the opening temperature of the thermostat 13, and then the actual outlet water temperature of the engine does not rise to near the target outlet water temperature value within a set time, then the thermostat 13 has a stuck fault. The set time can be 5 minutes.

[0036] The second operating condition is when the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase in the outlet water temperature is greater than or equal to a first threshold. Specifically, when the outlet water temperature is in the second operating condition, the controller is also used to determine whether there is coolant in the engine cooling system based on the current change in the engine outlet water temperature. In the second operating condition, the first threshold is set to 0.1℃ / s. When the engine is running at low speed and low load, and the actual outlet water temperature of the engine increases at a rate of ≥0.1℃ / s, exceeding the target outlet water temperature range (3℃) and continuing to rise, it is determined that there is no coolant in the cooling system. If the engine is used for bench testing, this deviation represents the control accuracy required for bench testing; if the engine is used for vehicle testing, this deviation represents the control accuracy required for bench (vehicle) testing.

[0037] In the absence of coolant in the cooling system, there are three fault conditions: the first fault condition, the second fault condition, and the third fault condition.

[0038] When the engine cooling system is in the first fault condition, the cooling system lacks coolant; when the engine cooling system is in the second fault condition, the engine water pump 1 is faulty; when the engine cooling system is in the third fault condition, the thermostat 13 is unable to open.

[0039] Therefore, when the cooling system has no coolant, it is necessary to check the cooling system to determine if the lack of coolant is the cause. The sensor needs to collect and transmit the engine's actual water pressure value. When the water temperature is in the second operating condition, the controller also uses the comparison between the actual water pressure value and the target water pressure value to determine if the engine water pump 1 is faulty. That is, the controller compares the engine's actual water pressure value with the target water pressure value: if the engine has no actual water pressure (i.e., the actual water pressure is 0), it is necessary to check if the engine water pump 1 is driving normally; if the actual water pressure value is less than the target water pressure value, it is determined that the engine water pump 1 is faulty. The engine water temperature sensor 3 needs to collect the engine's actual water temperature value. When the engine's actual water temperature value exceeds the opening temperature of the thermostat 13, and the engine's actual water temperature value continues to rise without stopping, it is determined that the thermostat 13 is unable to open.

[0040] In the second operating condition, the following checks can be performed sequentially: coolant deficiency in the cooling system, engine water pump 1 malfunction, and thermostat 13 failure to open. If coolant deficiency is detected, stop the check; if coolant is not deficient, begin checking engine water pump 1 for malfunction; if engine water pump 1 is found to be malfunctioning, stop the check; if coolant is not deficient and engine water pump 1 is functioning correctly, check thermostat 13 for failure to open.

[0041] The third operating condition is defined as follows: the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the engine outlet water temperature rise rate is greater than or equal to the second preset value but less than the first threshold value. The first threshold value is 0.1℃ / s, and the second threshold value is 2℃ / h. When the outlet water temperature is in the third operating condition, the controller is also used to determine whether the heat exchanger 5 is blocked based on the current change in the engine outlet water temperature. Specifically, when the engine is running under heavy load, the outlet water temperature cannot be stably controlled, and the temperature rises by more than 2℃ within 1 hour, it is determined that the heat exchanger 5 is blocked.

[0042] Based on the above embodiments, in this embodiment, the engine cooling system further includes a safety alarm 9, which is connected to the controller and is used to issue an alarm prompt based on the confirmation result of the controller.

[0043] In this embodiment, different fault types for the first, second, and third operating conditions are represented by different fault codes. When a fault is detected, the controller sends the corresponding fault code, and the safety alarm 9 activates the alarm upon receiving the fault code. Different fault codes correspond to different alarm methods:

[0044] In some possible embodiments, the safety alarm 9 can be a light alarm. For example, when the cooling system is low on coolant, the light alarm will illuminate red; when the engine water pump 1 malfunctions, the light alarm will illuminate yellow; when the thermostat 13 fails to open, the light alarm will illuminate blue; when the heat exchanger 5 is blocked, the light alarm will illuminate purple; and when the thermostat 13 is stuck, the light alarm will illuminate green.

[0045] In other possible embodiments, the safety alarm 9 can also be a voice alarm, for example, when the cooling system is low on coolant, the voice alarm will sound an alarm: "Cooling system low on coolant"; when the engine water pump 1 malfunctions, the voice alarm will sound an alarm: "Engine water pump 1 malfunctions"; when the thermostat 13 fails to open, the voice alarm will sound an alarm: "Thermostat 13 cannot open"; when the heat exchanger 5 is blocked, the voice alarm will sound an alarm: "Heat exchanger 5 is blocked"; when the thermostat 13 is stuck, the voice alarm will sound an alarm: "Thermostat 13 is stuck".

[0046] The above embodiments are merely various possible implementations of the embodiments of this application, and the embodiments of this application are not limited thereto.

[0047] In summary, by comparing the actual and target values ​​of the engine's outlet water temperature and pressure during engine operation, analyzing different situations of the engine cooling system and forming judgment criteria, it is possible to determine whether there are risks or malfunctions in the engine cooling system components.

[0048] At the same time, this system can determine the status of each component of the cooling system in advance, preventing greater damage to the engine caused by failure of the engine cooling system components.

[0049] Secondly, this application provides a fault detection method for an engine cooling system, comprising:

[0050] 101: Obtain the actual outlet water temperature of the engine;

[0051] 102: Compare the actual outlet water temperature of the engine with the target outlet water temperature of the engine;

[0052] 103: Based on the comparison results, confirm the current operating mode of the engine outlet water temperature;

[0053] 104: Based on the current operating mode of the engine outlet water temperature, determine the faulty components in the engine and heat exchanger 5.

[0054] In this application, when the engine is running, the actual outlet water temperature value of the engine is compared with the target outlet water temperature value to determine the operating mode of the outlet water temperature. Then, the different situations of the engine cooling system can be analyzed to determine the risks or faults of the engine and heat exchanger 5, and prevent greater damage to the engine caused by the failure of the engine cooling system components.

[0055] The engine includes an engine water pump 1, an engine water pump 13, and a thermostat 13. Along the coolant flow direction, the engine water pump 1, engine water pump 13, and thermostat 13 are connected in series on the pipe 12. The engine water pump 1 provides the driving force for the coolant flow in the cooling system, driving the coolant to circulate within the engine cooling system. The engine water jacket 2 serves as a coolant flow channel for heat exchange between the engine components and the coolant. The heat exchanger 5 is a key component of the engine cooling system; it is a cavity structure in which the engine coolant, after being cooled within the cavity, passes through the engine water pump 1 again before entering the engine water jacket 2 for engine cooling.

[0056] The operating modes for the outlet water temperature include: a first operating mode, a second operating mode, and a third operating mode; the first operating mode is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature value; the second operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the engine's outlet water temperature rise rate is greater than or equal to a first threshold; the third operating mode is when the actual outlet water temperature of the engine is greater than the target outlet water temperature value, and the engine's outlet water temperature rise rate is greater than or equal to a second threshold and less than a first threshold.

[0057] Based on the above embodiments, in this embodiment, the faulty components in the engine and heat exchanger 5 are determined based on the current engine outlet water temperature operating mode. The specific steps include: when the outlet water temperature is in the first operating condition, controlling the engine speed and load, and determining whether the thermostat 13 is stuck based on the current engine outlet water temperature change; when the outlet water temperature is in the second operating condition, determining whether the engine cooling system has coolant based on the current engine outlet water temperature change; and when the outlet water temperature is in the third operating condition, determining whether the heat exchanger 5 is blocked based on the current engine outlet water temperature change.

[0058] Specifically, the first operating condition is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature. When the outlet water temperature is in the first operating condition, the controller is also used to control the engine speed and load, and to confirm whether the thermostat 13 has a stuck fault: Specifically, when the actual outlet water temperature of the engine is abnormal, and the actual outlet water temperature value of the engine is less than or equal to the target outlet water temperature value, the engine speed is fixed, and the engine load is adjusted from 100% to 50%. At this time, the engine outlet water temperature sensor 3 continues to collect the actual outlet water temperature of the engine. If, with the engine speed fixed and the engine load adjusted from 100% to 50%, the engine outlet water temperature first decreases rapidly and then slowly rises to near the target outlet water temperature value, then the thermostat 13 is working normally; if the engine outlet water temperature first decreases rapidly to below the opening temperature of the thermostat 13, and then the actual outlet water temperature of the engine does not rise to near the target outlet water temperature value within a set time, then the thermostat 13 has a stuck fault. The set time can be 5 minutes.

[0059] The second operating condition is when the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase in the outlet water temperature is greater than or equal to a first threshold. Specifically, when the outlet water temperature is in the second operating condition, the controller is also used to determine whether there is coolant in the engine cooling system based on the current change in the engine outlet water temperature. In the second operating condition, the first threshold is set to 0.1℃ / s. When the engine is running at low speed and low load, and the actual outlet water temperature of the engine increases at a rate of ≥0.1℃ / s, exceeding the target outlet water temperature range (3℃) and continuing to rise, it is determined that there is no coolant in the cooling system. If the engine is used for bench testing, this deviation represents the control accuracy required for bench testing; if the engine is used for vehicle testing, this deviation represents the control accuracy required for bench (vehicle) testing.

[0060] In the absence of coolant in the cooling system, there are three fault conditions: the first fault condition, the second fault condition, and the third fault condition.

[0061] When the engine cooling system is in the first fault condition, the cooling system lacks coolant; when the engine cooling system is in the second fault condition, the engine water pump 1 is faulty; when the engine cooling system is in the third fault condition, the thermostat 13 is unable to open.

[0062] Therefore, when the cooling system has no coolant, it is necessary to check the cooling system to determine if the lack of coolant is the cause. The sensor needs to collect and transmit the engine's actual water pressure value. When the water temperature is in the second operating condition, the controller also uses the comparison between the actual water pressure value and the target water pressure value to determine if the engine water pump 1 is faulty. That is, the controller compares the engine's actual water pressure value with the target water pressure value: if the engine has no actual water pressure (i.e., the actual water pressure is 0), it is necessary to check if the engine water pump 1 is driving normally; if the actual water pressure value is less than the target water pressure value, it is determined that the engine water pump 1 is faulty. The engine water temperature sensor 3 needs to collect the engine's actual water temperature value. When the engine's actual water temperature value exceeds the opening temperature of the thermostat 13, and the engine's actual water temperature value continues to rise without stopping, it is determined that the thermostat 13 is unable to open.

[0063] In the second operating condition, the following checks can be performed sequentially: coolant deficiency in the cooling system, engine water pump 1 malfunction, and thermostat 13 failure to open. If coolant deficiency is detected, stop the check; if coolant is not deficient, begin checking engine water pump 1 for malfunction; if engine water pump 1 is found to be malfunctioning, stop the check; if coolant is not deficient and engine water pump 1 is functioning correctly, check thermostat 13 for failure to open.

[0064] The third operating condition is defined as follows: the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the engine outlet water temperature rise rate is greater than or equal to the second preset value and less than the first threshold value, i.e., ≥0.1℃ / s. When the outlet water temperature is in the third operating condition, the controller is also used to determine whether the heat exchanger 5 is blocked based on the current change in the engine outlet water temperature. Specifically, when the engine is running under heavy load, the outlet water temperature cannot be stably controlled, and the temperature rises by more than 2℃ within 1 hour, it is determined that the heat exchanger 5 is blocked.

[0065] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0066] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0067] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An engine cooling system, characterized in that, It includes: engine; A heat exchanger (5) is connected in series with the engine via a pipe (12); A sensor, which is connected to the engine, is used to collect and transmit the engine's actual outlet water temperature value; The controller is connected to the sensor and is used to receive the actual outlet water temperature value of the engine. The controller is also used to determine the operating mode of the outlet water temperature based on the comparison result between the actual outlet water temperature value and the target outlet water temperature value, so as to identify the faulty components in the engine and heat exchanger (5). The operating modes for the outlet water temperature include: first operating mode, second operating mode, and third operating mode; The first operating condition is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature. The second operating condition is that the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase of the outlet water temperature of the engine is greater than or equal to the first threshold. The third operating condition is that the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase of the outlet water temperature of the engine is greater than or equal to the second threshold and less than the first threshold. The engine includes a thermostat (13); When the outlet water temperature is the first operating condition, the controller is also used to control the engine speed and load, and to check whether the thermostat (13) has a stuck fault; When the outlet water temperature is in the second operating condition, the controller is also used to determine whether there is coolant in the engine cooling system based on the current change in the engine outlet water temperature. When the outlet water temperature is in the third operating condition, the controller is also used to determine whether the heat exchanger (5) is blocked based on the current change in the engine outlet water temperature. The engine also includes an engine water pump (1), and along the coolant flow direction, the thermostat (13) and the engine water pump (1) are connected in series on the pipeline (12); The sensor is also used to collect and send the actual water pressure value of the engine. When the water temperature is the second working condition, the controller is also used to determine whether the engine water pump (1) is faulty based on the comparison result between the actual water pressure value and the target water pressure value.

2. The engine cooling system as described in claim 1, characterized in that, The engine cooling system also includes: Safety alarm (9), which is connected to the controller, is used to issue an alarm prompt based on the confirmation result of the controller.

3. The engine cooling system as described in claim 1, characterized in that, The sensor includes: Engine outlet water temperature sensor (3), which is installed on pipeline (12).

4. A fault detection method for an engine cooling system as described in any one of claims 1-3, characterized in that, It includes: Obtain the actual coolant temperature value of the engine; Compare the engine's actual water outlet temperature with the engine's target water outlet temperature; Based on the comparison results, the operating mode of the current engine outlet water temperature was confirmed; Based on the current operating mode of the engine outlet water temperature, determine the faulty components in the engine and heat exchanger (5).

5. The fault detection method for an engine cooling system as described in claim 4, characterized in that: The engine includes a thermostat (13), and the operating modes of the outlet water temperature include: a first operating mode, a second operating mode, and a third operating mode; The first operating condition is when the actual outlet water temperature of the engine is less than or equal to the target outlet water temperature. The second operating condition is that the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase of the outlet water temperature of the engine is greater than or equal to the first threshold. The third operating condition is that the actual outlet water temperature of the engine is greater than the target outlet water temperature, and the rate of increase of the outlet water temperature of the engine is greater than or equal to the second threshold and less than the first threshold.

6. The fault detection method for an engine cooling system as described in claim 5, characterized in that, Based on the current operating mode of the engine outlet water temperature, the specific steps for determining the faulty components in the engine and heat exchanger (5) include: When the outlet water temperature is the first working condition, control the engine speed and load, and determine whether the thermostat (13) has a stuck fault based on the current change of the engine outlet water temperature. When the outlet water temperature is in the second operating condition, the engine cooling system is determined to have coolant based on the current change in engine outlet water temperature. When the outlet water temperature is in the third operating condition, the heat exchanger (5) is determined to be blocked based on the current change in the engine outlet water temperature.

7. The fault detection method for an engine cooling system as described in claim 6, characterized in that: Based on the current change in engine outlet water temperature, determine whether there is coolant in the engine cooling system. The specific steps include: when the engine outlet water temperature rise rate is greater than or equal to the first threshold, and the engine outlet water temperature exceeds the set range of the outlet water temperature target value, it is determined that there is no coolant in the engine cooling system. The absence of coolant in the engine cooling system includes the first fault condition, the second fault condition, and the third fault condition. When the engine cooling system is in the first fault condition, the engine cooling system lacks coolant. When the engine cooling system is in the second fault condition, the engine water pump (1) is faulty. When the engine cooling system is in the third fault condition, the thermostat (13) cannot open.

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