Fan control method for new energy heavy truck and fused heat management system

Abstract

The invention discloses a fan control method for a new energy heavy truck and a fusion heat management system in the field of new energy automobiles, and aims to solve the technical problems that an existing independent heat management system is low in efficiency and poor in collaboration, and an electronic fan is prone to faults due to dust accumulation under the high-dust working condition. The method comprises the steps that working condition parameters of the new energy heavy truck are obtained, wherein the working condition parameters comprise the motor temperature and the exhaust temperature and exhaust pressure of a compressor; based on the working condition parameters, the current working mode of the new energy heavy truck is judged, and the working mode comprises a refrigeration mode and a cleaning mode; when the refrigeration mode is executed, the rotating speed and the direction of the electronic fan are controlled through a pulse width modulation signal; and when the cleaning mode is executed and a preset ash removal triggering condition is met, the electronic fan is driven to rotate reversely so as to carry out ash removal operation. Intelligent and refined cooperative control of the shared electronic fan in the fusion heat management system is achieved, and system energy consumption is remarkably reduced on the premise that the refrigeration requirements of a battery, a motor and a cab are met.

Description

Technical Field

[0001] This invention relates to a fan control method and integrated thermal management system for new energy heavy-duty trucks, belonging to the field of new energy vehicle technology. Background Technology

[0002] In the current wave of new energy vehicles sweeping the globe, the automotive industry is undergoing a profound transformation. The transition from traditional gasoline vehicles to new energy vehicles is not merely a change in power source, but a comprehensive revolution in the concept of vehicle performance optimization. Energy management, especially thermal performance management, has become a core element determining the future performance of vehicles. Thermal management is central to the performance of new energy vehicles, ensuring stable powertrains, extending driving range, prolonging battery life, and supporting intelligent connectivity functions through precise temperature control. Optimizing the thermal management system makes driving more efficient, safe, and reliable. Independent thermal management systems, due to their inherent drawbacks such as low efficiency, high cost, poor space utilization, and poor coordination, are no longer sufficient to meet the increasingly demanding thermal management requirements of new energy heavy-duty trucks. Highly integrated and intelligent thermal management systems are the future direction, leading to the emergence of integrated thermal management. Integrated thermal management combines battery thermal management, motor cooling, and cab thermal management, unifying the management and distribution of heat, significantly improving energy efficiency, saving space, reducing costs, and improving system responsiveness and reliability. However, after integration, the heat pipe and electric fan are shared, requiring a redesign of the electric fan control strategy. Therefore, this paper proposes an integrated thermal management electric fan control strategy. Summary of the Invention

[0003] The purpose of this invention is to provide a fan control method and integrated thermal management system for new energy heavy trucks. This method can adjust the electronic fan of the integrated thermal management system based on the cooling needs of the power battery, motor, and driving. Under the premise of meeting the cooling requirements, it can improve the intelligence of electronic fan control, reduce the energy consumption of the whole vehicle, and improve the life of the power battery.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.

[0005] In a first aspect, the present invention provides a fan control method for new energy heavy-duty trucks, comprising: Obtain the operating parameters of the new energy heavy truck, including motor temperature, compressor exhaust temperature and exhaust pressure; Based on the aforementioned operating parameters, the current operating mode of the new energy heavy truck is determined. The operating mode includes a cooling mode and a cleaning mode. The cooling mode includes one or more combinations of driving cooling mode, motor cooling mode, and battery cooling mode. When the cooling mode is activated, the speed and direction of the current electric fan are controlled via pulse width modulation signals, specifically including: When the cooling mode is motor cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the motor temperature, and the electronic fan is controlled to rotate forward at the corresponding speed; when the cooling mode is driving cooling mode / battery cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the compressor exhaust temperature / exhaust pressure, and the electronic fan is controlled to rotate forward at the corresponding speed; when multiple combinations of cooling modes are working simultaneously, the maximum duty cycle that satisfies the electronic fan's opening conditions is output, and the electronic fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle. When the cleaning mode is executed, the electronic fan is driven to reverse to perform the cleaning operation when the preset dust removal trigger conditions are met.

[0006] In conjunction with the first aspect, further, before determining the current operating mode of the new energy heavy truck, the following steps are included: If the speed of the new energy heavy truck is higher than the preset speed threshold, the electronic fan will be turned on; otherwise, the electronic fan will not be activated.

[0007] In conjunction with the first aspect, further, linearly adjusting the duty cycle of the pulse width modulation signal according to the motor temperature and controlling the electronic fan to rotate forward at a corresponding speed includes: When the temperature of the drive motor is greater than a preset first temperature threshold and less than a second temperature threshold, the duty cycle of the linearly output pulse width modulation signal is increased linearly from the duty cycle corresponding to the first temperature threshold to the upper limit duty cycle corresponding to the second temperature threshold. When the temperature of the drive motor is greater than the second temperature threshold, the upper limit duty cycle is output, and the electronic fan is controlled to rotate forward at the highest speed.

[0008] In conjunction with the first aspect, further, the motor temperature includes the drive motor temperature, the drive motor controller temperature, the upper motor temperature, and the upper motor controller temperature.

[0009] In conjunction with the first aspect, furthermore, the duty cycle of the pulse width modulation signal is linearly adjusted according to the exhaust temperature or exhaust pressure of the air conditioning compressor and the battery refrigeration compressor, and the electronic fan is controlled to rotate forward at the corresponding speed, including: When the compressor's exhaust temperature is lower than a preset third temperature threshold / the compressor's exhaust pressure is lower than a preset pressure threshold, a constant base duty cycle is output, and the electric fan is controlled to rotate forward at a constant speed. When the exhaust temperature of the compressor is higher than the third temperature threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of temperature change of the exhaust temperature exceeding the third temperature threshold until a preset upper limit duty cycle is reached; or when the exhaust pressure of the compressor is higher than the pressure threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of pressure change of the exhaust pressure exceeding the pressure threshold until the upper limit duty cycle is reached. If the exhaust temperature and exhaust pressure of the compressor both exceed their respective thresholds, the maximum duty cycle of the two will be selected for output.

[0010] In conjunction with the first aspect, further, the maximum duty cycle that satisfies the conditions for the electronic fan to start is taken for output, and the electronic fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle, including: When at least two of the driving cooling mode, motor cooling mode and battery cooling mode simultaneously issue a request to turn on the electric fan, the duty cycle of the pulse width modulation signal output in each mode is obtained. The electronic fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle from the duty cycles of the pulse width modulation signals in each mode.

[0011] In conjunction with the first aspect, further, when a preset dust-cleaning trigger condition is met, the electronic fan is driven to reverse in order to perform a dust-cleaning operation, including: When the new energy heavy truck is powered on with high voltage, it is detected whether the backflush flag is set. If it is not set and it is determined to be the first power-on of the day, it is further determined whether the preset dust removal trigger condition is met. When all dust removal triggering conditions are met, the electronic fan is controlled to reverse at full speed with a preset reverse duty cycle, and stops after reaching the set reverse duration. After the dust removal operation is completed, update the dust removal status flag.

[0012] In conjunction with the first aspect, the dust removal triggering conditions further include whether the new energy vehicle handbrake signal is valid, whether the battery's state of charge is not lower than the preset charge threshold, and whether the electric fan itself is fault-free.

[0013] In a second aspect, a fusion thermal management system for new energy heavy trucks is characterized by comprising a fusion thermal management controller, an electronic fan, a battery thermal management circuit, and a motor thermal management circuit. Both the battery thermal management circuit and the motor thermal management circuit are electrically connected to the integrated thermal management controller. The integrated thermal management controller controls the speed and direction of the electronic fan according to the cooling requirements of the battery thermal management circuit and the motor thermal management circuit, in accordance with the fan control method for new energy heavy trucks as described in the first aspect.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By constructing an integrated thermal management system that combines cab, battery, and motor cooling, and proposing an intelligent control strategy for a shared electric fan, the problem of low efficiency and poor coordination in traditional independent systems is fundamentally solved. This method can dynamically and linearly adjust the speed of the shared electric fan based on operating condition signals such as motor temperature, compressor exhaust temperature, or pressure. This ensures optimal matching of heat dissipation capacity and energy consumption under multi-mode cooling demands, significantly reducing overall vehicle energy consumption while guaranteeing the stability of the powertrain and battery life.

[0015] In addition, for the high-dust working environment of heavy trucks, an innovative cleaning mode with reverse electric fan has been introduced. By automatically performing high-speed backflushing under safe conditions, the accumulated dust is effectively removed, avoiding failures caused by radiator blockage or electric fan eccentricity, and greatly improving the reliability and durability of the electric fan and the entire thermal management system under harsh working conditions. Attached Figure Description

[0016] Figure 1 The diagram shown is a schematic of a fusion thermal management architecture provided by an embodiment of the present invention; Figure 2 The diagram shown is a schematic diagram of the selected electronic fan control method provided in an embodiment of the present invention; Figure 3 The diagram shows a flowchart of the motor cooling control strategy provided in an embodiment of the present invention; Figure 4 The diagram shows a flowchart of the independent start-up control strategy for air conditioning or battery cooling provided in an embodiment of the present invention. Figure 5 The diagram shows a flowchart of the dust removal mode - electronic fan and air conditioner back-blowing strategy provided in an embodiment of the present invention; In the diagram: 1. Compressor; 2. Discharge temperature switch; 3. Pressure sensor; 4. Condenser; 5. Refrigerant solenoid valve; 6. Thermal management expansion valve; 7. Evaporator; 8. Air conditioning compressor; 9. Gas-liquid separator; 10. Pressure sensor; 11. Electronic expansion valve; 12. Plate heat exchanger; 13. Water pump; 14. Low-temperature radiator; 15. Four-way valve; 16. Expansion tank; 17. Electronic water pump; 18. Battery-cooled compressor; 19. First temperature sensor; 20. Second temperature sensor; 21. Expansion tank; 22. Electric fan; 23. Drive motor; 24. Power battery. Detailed Implementation

[0017] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0018] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Example 1

[0019] See Figure 3 This embodiment introduces a fan control method for new energy heavy-duty trucks, based on a highly integrated fusion thermal management system. This system integrates three originally independent thermal management loops: cab cooling, battery cooling, and motor cooling, allowing them to operate independently or collaboratively, and sharing key components such as the condenser 4, low-temperature radiator 14, and electric fan 22. Based on this fusion topology, the electric fan control method includes: Real-time acquisition of operating parameters of new energy heavy trucks, including motor temperature, compressor exhaust temperature and exhaust pressure; Based on operating parameters, determine the current operating mode of the new energy heavy truck, which includes cooling mode and cleaning mode; among them, cooling mode includes one or more combinations of driving cooling mode, motor cooling mode and battery cooling mode; When the cooling mode is activated, the speed and direction of the shared electric fan 22 are controlled via pulse width modulation (PWM) signals, specifically including: When the cooling mode is motor cooling mode, the duty cycle of PWM is linearly adjusted according to the motor temperature, and the electronic fan 22 is controlled to rotate forward at the corresponding speed. When the cooling mode is driving cooling mode or battery cooling mode, the duty cycle of PWM is linearly adjusted according to the compressor's exhaust temperature / exhaust pressure, and the electronic fan 22 is controlled to rotate forward at the corresponding speed to enhance heat dissipation. When multiple combinations of cooling modes are working simultaneously, the maximum duty cycle that meets the conditions for the electronic fan 22 to start is used for output, and the electronic fan 22 is controlled to rotate forward at the speed corresponding to the maximum duty cycle, thereby ensuring that the heat dissipation capacity meets the most demanding working conditions, thus achieving efficient energy utilization and reliable system operation.

[0020] In addition, for the harsh dust working conditions often faced by new energy heavy trucks, the method also specifically integrates a cleaning mode. When the cleaning mode is executed, when the preset dust cleaning trigger condition is met, the electronic fan 22 is automatically driven to rotate at high speed in reverse, and the accumulated dust is purged by the airflow. This intelligent fan control method based on the integrated thermal management framework not only solves the logic conflicts and energy consumption problems in multiple modes through a unified and adaptive strategy, but also significantly improves the working reliability and overall life of the electronic fan 22 in harsh environments with its self-cleaning function. Embodiment 2

[0021] Before turning on the electronic fan 22, it is first necessary to determine whether the vehicle speed of the new energy heavy truck is higher than the preset speed threshold. If it is higher, the control of the electronic fan 22 is turned on; otherwise, the electronic fan 22 is not enabled. Preferably, the set speed threshold is 5 km / h. When the vehicle speed of the new energy heavy truck is higher than 5 km / h, the electronic fan 22 is turned on for control; when the vehicle speed is not greater than 5 km / h, it is considered that the vehicle is in a stationary or micro-motion state. At this time, the motor temperature is on the high side, but the electronic fan 22 is not enabled to avoid blowing up dust on the ground or frequent start and stop.

[0022] The electronic fan 22 adopted in the embodiment of the present invention is a fan with PWM control, which has the functions of forward rotation and reverse rotation, ensuring both heat dissipation and efficient dust cleaning. Through Figure 2 It can be seen that the rotation speed of the electronic fan 22 is related to PWM control, specifically including: When the duty cycle of PWM < 50%, the electronic fan 22 does not rotate; If 50% ≤ the duty cycle of PWM ≤ 55%, the electronic fan 22 starts to rotate forward; if 55% < the duty cycle of PWM > 95%, the electronic fan 22 starts to increase its rotation speed, and the duty cycle is proportional to the rotation speed of the electronic fan 22; when the duty cycle of PWM = 95%, the electronic fan 22 reaches the maximum rotation speed (100%); When the forward rotation speed decreases, the electronic fan 22 does not stop immediately, that is, when the duty cycle of PWM decreases to 35%, it still maintains the forward rotation at the lowest rotation speed. The purpose is to prevent frequent start and stop and improve the service life and stability of the vehicle; When the reverse rotation speed increases, if the duty cycle of PWM = 25%, the electronic fan 22 immediately starts to rotate in reverse, and different from the forward rotation mode, there is no linear speed increase process and it directly turns to the highest reverse rotation speed; if the duty cycle of PWM decreases to 6%, the electronic fan 22 immediately stops, aiming to quickly end the reverse blowing and dust cleaning process.

[0023] See Figure 3 , based on the above definition of the relationship between the forward and reverse rotation of the electronic fan 22 and the PWM signal, precise control strategies can be executed for different refrigeration requirements, specifically as follows: (1) Motor refrigeration fan control strategy Step 1: When the cooling mode is motor cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the motor temperature, and the electronic fan 22 is controlled to rotate forward at the corresponding speed.

[0024] Specifically, when the temperature of the drive motor is greater than a preset first temperature threshold and less than a second temperature threshold, the duty cycle of the linearly output pulse width modulation signal is increased linearly from the duty cycle corresponding to the first temperature threshold to the upper limit duty cycle corresponding to the second temperature threshold. When the temperature of the drive motor is greater than the second temperature threshold, the upper limit duty cycle is output, and the electronic fan 22 is controlled to rotate forward at the highest speed.

[0025] The motor temperature includes the drive motor temperature, the drive motor controller temperature, the upper motor temperature, and the upper motor controller temperature.

[0026] For example, when the speed of the new energy heavy truck exceeds 5km / h, the electronic fan 22 is activated. When the temperature of the drive motor is between 120℃ and 140℃, the integrated thermal management controller outputs a PWM wave at 65%-95% for linear speed regulation. When the temperature of the drive motor is ≥140℃, the integrated thermal management controller outputs a PWM wave at 95%, meaning the electronic fan 22 runs at full speed, thereby quickly removing heat and preventing demagnetization of the permanent magnet or burnout of the windings.

[0027] When the temperature of the drive motor controller is less than 65℃, the integrated thermal management controller outputs a PWM wave at 65%-95% for linear speed regulation; when the temperature of the drive motor controller is greater than or equal to 65℃, the integrated thermal management controller outputs a PWM wave at 95%, meaning the electronic fan operates at full speed.

[0028] Because the upper motor has poor heat dissipation and low power, when the upper motor temperature is between 60℃ and 80℃, the integrated thermal management controller outputs a PWM wave at 65%-95% for linear speed regulation; when the upper motor temperature is ≥140℃, the integrated thermal management controller outputs a PWM wave at 95%, meaning the electronic fan runs at full speed.

[0029] It should be noted that the upper motor controller and the drive motor controller share the same threshold, which will not be repeated here.

[0030] (2) Control strategy for air conditioning or battery-powered cooling fans Step 2: When the cooling mode is driving cooling mode or battery cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the exhaust temperature or exhaust pressure of the compressor, and the electric fan 22 is controlled to rotate forward at the corresponding speed.

[0031] See Figure 4The control of the air conditioning and battery-cooled electronic fan 22 is based on the exhaust temperature and exhaust pressure of the air conditioning compressor and the battery-cooled compressor outlet (high-pressure side). The higher the exhaust temperature and exhaust pressure, the faster the electronic fan 22 needs to rotate to dissipate heat, as detailed below: When the compressor's exhaust temperature is lower than the preset third temperature threshold or the compressor's exhaust pressure is lower than the preset pressure threshold, a constant base duty cycle is output, and the electric fan 22 is controlled to rotate forward at a constant speed. When the compressor's exhaust temperature is higher than the third temperature threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of temperature change of the exhaust temperature exceeding the third temperature threshold until a preset upper limit duty cycle is reached. Or when the compressor's exhaust pressure is higher than the pressure threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of pressure change of the exhaust pressure exceeding the pressure threshold until the upper limit duty cycle is reached. If the compressor's exhaust temperature and exhaust pressure both exceed their respective thresholds, the maximum duty cycle of the two will be selected for output.

[0032] Preferably, the third temperature threshold is set to 100°C and the pressure threshold is set to 10 bar.

[0033] For example, when the compressor's exhaust temperature is <100℃ or <10bar, the integrated thermal management controller linearly outputs a PWM wave of 65%. At this time, the electronic fan 22 does not adjust with temperature / pressure, avoiding frequent vibration, that is, the electronic fan 22 operates at a constant speed. When the compressor's exhaust temperature is >100℃, first calculate the temperature change, and then calculate the duty cycle of the linear output of the fusion thermal management controller based on the temperature change. The expression is as follows: T2 = T1 - 100 A = 65% + T2 * 5% Where T2 represents the temperature change; T1 represents the current exhaust temperature of the compressor; and A represents the duty cycle based on the exhaust temperature.

[0034] When the duty cycle of the output based on exhaust temperature exceeds 95%, the output will be based on a 95% duty cycle.

[0035] When the compressor's discharge pressure is greater than 10 bar, the pressure change is first calculated, and then the duty cycle of the linear output of the fusion thermal management controller is calculated based on the pressure change. The expression is as follows: P2 = P1 - 100 B = 65% + P² * 5% Where P2 represents the pressure change; P1 represents the current discharge pressure of the compressor; and B represents the duty cycle based on the discharge pressure output.

[0036] When the duty cycle based on the exhaust pressure output exceeds 95%, the electric fan 22 operates at full speed according to the 95% duty cycle.

[0037] It should be noted that the duty cycle is locked at 95% based on the compressor's exhaust temperature and pressure output in order to leave a 5% margin for the hardware and avoid long-term noise / lifespan issues caused by operating at 100%.

[0038] (3) Activate at least two cooling control strategies Step 3: When multiple combinations in the cooling mode are working simultaneously, the maximum duty cycle that meets the conditions for the electronic fan 22 to start is used for output, and the electronic fan 22 is controlled to rotate forward at the speed corresponding to the maximum duty cycle.

[0039] Specifically, when at least two of the driving cooling mode, motor cooling mode and battery cooling mode simultaneously request to turn on the electric fan 22, the duty cycle of the pulse width modulation signal output in each mode is obtained, and the duty cycle with the largest value is selected from the duty cycles of the pulse width modulation signal in each mode as the final output, and the electric fan 22 is controlled to rotate forward at the speed corresponding to the maximum duty cycle.

[0040] (4) Cleaning mode In response to the problem that new energy heavy trucks often operate at construction sites where there is a lot of dust, and users cannot clean them in time, leading to the accumulation of dust and subsequent fan malfunctions, this invention adds a back-blowing cleaning mode to the fan control strategy.

[0041] See Figure 5 When the new energy heavy truck is powered on, it is detected whether the backflush flag is set. If it is not set and it is determined to be the first power-on of the day, it is further determined whether the preset dust removal triggering conditions are met. When all dust removal triggering conditions are met, the electronic fan 22 is controlled to reverse at full speed with a preset reverse duty cycle, and stops after reaching the set reverse duration. After the dust removal operation is completed, update the dust removal status flag.

[0042] Among them, the dust removal triggering conditions include, but are not limited to, whether the new energy handbrake signal is valid, the battery's state of charge is not lower than the preset state of charge threshold, and the electronic fan 22 itself is not faulty.

[0043] Preferably, the charge threshold is set to 25%. Example 3

[0044] See Figure 1A fusion thermal management system for new energy heavy-duty trucks is disclosed. This system, with a fusion thermal management controller at its core, integrates a cooling circuit, battery thermal management, and motor cooling circuit. An electronic fan 22 provides forced convection for the fusion thermal management. Both the battery thermal management circuit and the motor thermal management circuit are electrically connected to the fusion thermal management controller. The fusion thermal management controller controls the speed and direction (forward / reverse rotation) of the electronic fan 22 according to the cooling requirements of the battery thermal management circuit and the motor thermal management circuit, following the electronic fan control methods for new energy heavy-duty trucks described in Embodiments 1 and 2.

[0045] Specifically, the refrigeration circuit includes a compressor 1. The outlet of the compressor 1 is sequentially connected to an exhaust temperature switch 2 and a pressure sensor 3. The subsequent pipeline splits into two paths: one leads to the condenser 4, and the other is controlled by a refrigerant solenoid valve 5 as a bypass. The refrigerant flowing out of the condenser 4 is throttled by a thermal management expansion valve 6 and then flows through the evaporator 7 in the cab thermal management circuit to cool the driver. The other path is throttled by an electronic expansion valve 11 and then flows through the plate heat exchanger 12 in the battery thermal management circuit to cool the battery. An air conditioning compressor (APTC) 8 for heating is connected in parallel on the branch where the evaporator 7 is located. Simultaneously, it flows through the plate heat exchanger 12 in the battery thermal management circuit as needed to cool the power battery 24. Finally, the refrigerant collects and flows through a gas-liquid separator 9 before returning to the compressor 1, forming a complete cycle. In a further embodiment of the invention, a pressure sensor 10 is also provided before the inlet of the gas-liquid separator 9.

[0046] The battery thermal management circuit includes an electronic water pump 17, a battery cooling compressor (WPTC) 18, a first temperature sensor 19, a second temperature sensor 20, an expansion tank 21, and a power battery 24. A four-way valve 15 returns the water to the water pump inlet. In cooling mode, WPTC 18 is not working. The water pump pressurizes the coolant cooled by the heat exchanger 12 and then flows it through the power battery 24. The first temperature sensor 19 and the second temperature sensor 20 monitor the battery inlet and outlet temperatures. In heating mode, the cooling circuit is not working. The coolant is heated by WPTC 18 and flows through the power battery 24 to transfer heat to the power battery 24 and heat it.

[0047] The motor thermal management circuit includes a drive motor 23, a low-temperature radiator 14, an expansion tank 16, a water pump 13, and a four-way valve 15. The water pump 13 pressurizes the coolant to provide power. This coolant flows through the drive motor 23, carrying away its heat, then flows through the radiator 14 and is forced to cool by the electric fan 22. Finally, it flows back to the water pump 13 after passing through the four-way valve 15, forming a closed-loop water circuit.

[0048] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A fan control method for new energy heavy-duty trucks, characterized in that, include: Obtain the operating parameters of the new energy heavy truck, including motor temperature, compressor exhaust temperature and exhaust pressure; Based on the aforementioned operating parameters, the current operating mode of the new energy heavy truck is determined. The operating mode includes a cooling mode and a cleaning mode. The cooling mode includes one or more combinations of driving cooling mode, motor cooling mode, and battery cooling mode. When the cooling mode is activated, the speed and direction of the current electric fan are controlled via pulse width modulation signals, specifically including: When the cooling mode is motor cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the motor temperature, and the electronic fan is controlled to rotate forward at the corresponding speed; when the cooling mode is driving cooling mode / battery cooling mode, the duty cycle of the pulse width modulation signal is linearly adjusted according to the compressor exhaust temperature / exhaust pressure, and the electronic fan is controlled to rotate forward at the corresponding speed; when multiple combinations of cooling modes are working simultaneously, the maximum duty cycle that satisfies the electronic fan's opening conditions is output, and the electronic fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle. When the cleaning mode is executed, the electronic fan is driven to reverse to perform the cleaning operation when the preset dust removal trigger conditions are met.

2. The fan control method for new energy heavy-duty trucks according to claim 1, characterized in that, Before determining the current operating mode of the new energy heavy truck, the following steps are included: If the speed of the new energy heavy truck is higher than the preset speed threshold, the electronic fan will be turned on; otherwise, the electronic fan will not be activated.

3. The fan control method for new energy heavy-duty trucks according to claim 1, characterized in that, The duty cycle of the pulse width modulation signal is linearly adjusted according to the motor temperature, and the electronic fan is controlled to rotate forward at a corresponding speed, including: When the temperature of the drive motor is greater than a preset first temperature threshold and less than a second temperature threshold, the duty cycle of the linearly output pulse width modulation signal is increased linearly from the duty cycle corresponding to the first temperature threshold to the upper limit duty cycle corresponding to the second temperature threshold. When the temperature of the drive motor is greater than the second temperature threshold, the upper limit duty cycle is output, and the electronic fan is controlled to rotate forward at the highest speed.

4. The fan control method for new energy heavy trucks according to claim 3, characterized in that, The motor temperature includes the drive motor temperature, the drive motor controller temperature, the upper motor temperature, and the upper motor controller temperature.

5. The fan control method for new energy heavy-duty trucks according to claim 1, characterized in that, The duty cycle of the pulse width modulation signal is linearly adjusted based on the exhaust temperature and pressure of the air conditioning compressor and the battery refrigeration compressor, and the electronic fan is controlled to rotate forward at the corresponding speed, including: When the compressor's exhaust temperature is lower than a preset third temperature threshold / the compressor's exhaust pressure is lower than a preset pressure threshold, a constant base duty cycle is output, and the electric fan is controlled to rotate forward at a constant speed. When the exhaust temperature of the compressor is higher than the third temperature threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of temperature change of the exhaust temperature exceeding the third temperature threshold until a preset upper limit duty cycle is reached; or when the exhaust pressure of the compressor is higher than the pressure threshold, the duty cycle of the pulse width modulation signal is linearly increased according to the amount of pressure change of the exhaust pressure exceeding the pressure threshold until the upper limit duty cycle is reached. If the exhaust temperature and exhaust pressure of the compressor both exceed their respective thresholds, the maximum duty cycle of the two will be selected for output.

6. The fan control method for new energy heavy trucks according to claim 1, characterized in that, The maximum duty cycle that satisfies the conditions for the electric fan to start is output, and the electric fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle, including: When at least two of the driving cooling mode, motor cooling mode and battery cooling mode simultaneously issue a request to turn on the electric fan, the duty cycle of the pulse width modulation signal output in each mode is obtained. The electronic fan is controlled to rotate forward at the speed corresponding to the maximum duty cycle from the duty cycles of the pulse width modulation signals in each mode.

7. The fan control method for new energy heavy trucks according to claim 1, characterized in that, When the preset dust removal trigger condition is met, the electronic fan is driven to reverse in order to perform a dust removal operation, including: When the new energy heavy truck is powered on with high voltage, it is detected whether the backflush flag is set. If it is not set and it is determined to be the first power-on of the day, it is further determined whether the preset dust removal trigger condition is met. When all dust removal triggering conditions are met, the electronic fan is controlled to reverse at full speed with a preset reverse duty cycle, and stops after the set reverse duration is reached. After the dust removal operation is completed, update the dust removal status flag.

8. The fan control method for new energy heavy trucks according to claim 1, characterized in that, The dust removal triggering conditions include whether the new energy handbrake signal is valid, whether the battery's state of charge is not lower than a preset charge threshold, and whether the fan itself is fault-free.

9. A fusion thermal management system for new energy heavy-duty trucks, characterized in that, This includes a fusion thermal management controller, an electric fan (22), a battery thermal management circuit, and a motor thermal management circuit; The battery thermal management circuit and the motor thermal management circuit are both electrically connected to the fusion thermal management controller. The fusion thermal management controller controls the speed and direction of the electronic fan (22) according to the cooling requirements of the battery thermal management circuit and the motor thermal management circuit, in accordance with the control method of the electronic fan (22) for new energy heavy trucks as described in any one of claims 1-8.

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