Hybrid engineering vehicle thermal management system, method and excavator

Abstract

The present application relates to a kind of hybrid engineering vehicle thermal management system, method and excavator, the thermal management system includes engine coolant circuit, electrical component coolant circuit, fuel heating circuit and vehicle controller VCU;The VCU is electrically connected with each component in engine coolant circuit, electrical component coolant circuit, fuel heating circuit;The thermal management method is based on the thermal management system, and the VCU gathers each cooling circuit each component temperature and judges whether heating or cooling is needed layer by layer;The excavator installs the thermal management system and uses the thermal management method to carry out thermal management dynamic control.The present application carries out thermal management dynamic control to the permanent magnet motor system, electronic control system, engine system of hybrid engineering vehicle, improves the adaptability and reliability of hybrid engineering vehicle under extremely low temperature working condition.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal management systems for engineering machinery, specifically relating to a thermal management system, method, and excavator for hybrid engineering vehicles. Background Technology

[0002] With increasing global attention to energy conservation, emission reduction, and environmental issues, the construction machinery industry has developed more environmentally friendly and energy-efficient power technologies, such as pure electric power and hybrid power. In the excavator sector, hybrid excavators, as a technological iteration of traditional fuel-powered excavators, have been widely researched and applied in recent years. Hybrid excavators add a drive motor and a power battery to the traditional engine power architecture, allowing the engine and drive motor to work together, significantly improving energy efficiency while effectively regulating engine output torque. Since excavators are widely used in various construction environments, including operations in extremely cold regions, extremely low temperature environments (-30℃ and below) pose a severe challenge to the three-electric system of hybrid excavators. Existing thermal management technologies are insufficient to meet their operational requirements under extreme low-temperature conditions.

[0003] For permanent magnet motor systems, existing thermal management systems mostly focus on designs for ambient and high-temperature conditions, lacking specific designs for extremely low-temperature conditions. Permanent magnet motors rely on high-performance permanent magnets to provide the magnetic field, eliminating the need for additional excitation windings, resulting in a more compact and efficient structure. However, in extremely low-temperature environments, permanent magnet motors face performance degradation. When the ambient temperature drops below -30°C, the magnetic flux density of the permanent magnets decreases significantly, leading to reduced motor output torque and a substantial drop in motor efficiency. More seriously, if the permanent magnets enter an irreversible demagnetization zone due to low temperatures, they will be permanently damaged, directly affecting motor operation. Existing thermal management systems cannot effectively prevent demagnetization. Furthermore, in terms of lubrication, extremely low temperatures cause a sharp increase in the viscosity of the motor lubricating oil, worsening its flow properties. This prevents effective lubrication of critical rotating components such as bearings, significantly increasing frictional resistance between components, increasing operational losses, and in severe cases, even causing starting difficulties, stalling, and other malfunctions, ultimately affecting the excavator's operating efficiency and reliability.

[0004] For electronic control systems, in extremely low temperatures, key parameters such as capacitance and resistance values ​​change with decreasing temperature, leading to circuit instability and reduced control accuracy. Chips experience limited processing speed and decreased stability at extremely low temperatures, making them prone to control signal delays and misjudgments, affecting the coordinated operation of the motor and electronic control system. Furthermore, extremely low temperatures can cause faults such as poor contact and breakage in the electronic control system, resulting in a very high risk of signal interruption. Once signal transmission is interrupted, the motor cannot be effectively controlled. Simultaneously, extremely low temperatures can interfere with the operation of sensors inside the motor and electronic control system, causing deviations in the collected current and voltage data, reducing the reliability and safety of the hybrid system.

[0005] Therefore, there is an urgent need to propose a thermal management system and method for hybrid engineering vehicles suitable for extremely low temperature environments, so as to improve the environmental adaptability and operational reliability of engineering machinery such as hybrid excavators under extreme working conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a thermal management system, method and excavator for hybrid engineering vehicles, which dynamically regulates the thermal management of the permanent magnet motor system and electronic control system of hybrid engineering vehicles, thereby improving the adaptability and reliability of hybrid engineering vehicles under extremely low temperature conditions.

[0007] The objective of this invention is achieved as follows: A thermal management system for a hybrid engineering vehicle includes an engine coolant circuit, an electrical component coolant circuit, a fuel heating circuit, and a vehicle control unit (VCU); the VCU is electrically connected to each component in the engine coolant circuit, the electrical component coolant circuit, and the fuel heating circuit. The engine coolant circuit includes an engine, a second water pump, a second electronic four-way valve, a first radiator, and a third electronic four-way valve connected in series with pipes at both ends. The electrical component coolant circuit includes a motor controller, a motor set, a fourth electronic four-way valve, a second radiator, a first electronic four-way valve, and a third water pump, which are connected in series with the first and last pipes connected in series. The first electronic four-way valve and the second electronic four-way valve are connected by pipelines; the third electronic four-way valve and the fourth electronic four-way valve are connected by pipelines. The fuel heating circuit includes a fuel heater, a first water pump connected to the outlet of the fuel heater, and a first two-position four-way valve and a second two-position four-way valve connected in parallel to the inlet of the fuel heater and the outlet of the first water pump. The first two-position four-way valve is connected to the pipelines of the second electronic four-way valve and the third electronic four-way valve of the engine coolant circuit, respectively. The second two-position four-way valve is connected to the pipelines of the first electronic four-way valve and the fourth electronic four-way valve of the electrical component coolant circuit, respectively.

[0008] Furthermore, the motor controller includes a first controller and a second controller connected in series, which respectively control the driving of different motors.

[0009] Furthermore, the motor unit includes a first motor, a second motor, and a third motor, wherein the first motor and the second motor are connected in parallel and then connected in series with the third motor.

[0010] Furthermore, the water inlets of the first motor and the second motor are diverted through a third three-way valve, and the water outlets are combined through a fourth three-way valve, thus achieving parallel connection in the electrical component coolant circuit.

[0011] Furthermore, the first two-position four-way valve and the second two-position four-way valve are connected in parallel to the fuel heating circuit via the second three-way valve and the first three-way valve.

[0012] Furthermore, the engine is equipped with an engine controller (ECU) and a first temperature sensor, and the ECU is electrically connected to the VCU.

[0013] Furthermore, a second temperature sensor electrically connected to the VCU is provided in the coolant circuit of the electrical components.

[0014] Furthermore, the cooling fans of the first and second heat sinks are high-voltage electronic fans, and the two heat sinks are respectively equipped with a first high-voltage electronic fan and a second high-voltage electronic fan.

[0015] Furthermore, the VCU controls the first two-position four-way valve and the second two-position four-way valve to close only one valve at a time, and controls the four connectors of the first electronic four-way valve, the second electronic four-way valve, the third electronic four-way valve, and the fourth electronic four-way valve to connect only two connectors at a time.

[0016] A thermal management method for hybrid engineering vehicles, implemented based on any of the aforementioned hybrid engineering vehicle thermal management systems, includes the following specific operation steps: S1. Preset the overheating temperature Tg of the electrical component coolant and the overheating temperature Tf of the engine coolant in the VCU, and at the same time, preset the corresponding overcooling temperature TDn for each motor and the corresponding overcooling temperature TCm for each controller. S2. The VCU collects the coolant temperature in the engine coolant circuit and the electrical component coolant circuit, where Ta is the coolant temperature collected in the electrical component coolant circuit, Tdn is the temperature collected by any motor in the motor set, Tcm is the temperature collected by any controller of the motor controller, and Te is the engine temperature collected. S3 and VCU will analyze the collected temperature data layer by layer. First, based on the collected temperature Ta of the electrical component coolant circuit, they will determine and control the regulation actions of the entire thermal management system. S31. When Ta≥0, if Ta<Tg, it indicates that the temperature of the electrical component cooling water circuit is normal. At this time, the fuel heater and the cooling fan of the second radiator are both stationary and not working. If Ta≥Tg, it indicates that the electrical component cooling water circuit has entered the overheating range. At this time, the VCU controls the connection of connectors 1 and 3 of the first electronic four-way valve and the connection of connectors 1 and 3 of the fourth electronic four-way valve. The second radiator is connected in series to the electrical component cooling water circuit. At the same time, the VCU controls the third water pump to increase the pumping flow and the second radiator cooling fan to infinitely adjust the speed until Ta<Tg. S32. When Ta < 0, if Tdn < TDn, it indicates that the nth motor is in an extremely low temperature state and requires a fuel heater to provide auxiliary heating for the electrical circuit. At this time, the second two-position four-way valve is connected, the 1 and 2 connectors of the first electronic four-way valve are connected, the 1 and 2 connectors of the fourth electronic four-way valve are connected, the second radiator cooling fan stops, and the third water pump flow rate is infinitely adjustable. If Tdn ≥ TDn, then proceed to the next motor judgment operation. Repeat this step until all motors are processed, and then proceed to the next step. S33. If Tcm < TCm, it means that the m-th controller is in an extremely low temperature state and the fuel heater is needed to provide auxiliary heating for the electrical circuit. At this time, the VCU controls the fuel heating circuit and the electrical cooling water circuit to provide auxiliary heating according to step S32. If Tcm ≥ TCm, the judgment operation of the next controller is performed. This step is repeated until all controllers are processed, and then the next operation is performed. S34. If Te≤0, it means that the engine cooling water circuit is in an overcooled state and requires the fuel heater to assist in heating it. At this time, the first two-position four-way valve is connected, the 1 and 2 connectors of the second electronic four-way valve are connected, the 1 and 2 connectors of the third electronic four-way valve are connected, the first radiator cooling fan stops, and the second water pump is infinitely adjustable. If Te>0, proceed to the next step. S35. If Te < Tf, it indicates that the engine cooling water temperature is normal. At this time, the engine cooling water circuit assists in heating the electrical component cooling water circuit. At this time, the 1 and 4 connectors of the third electronic four-way valve are connected, the 1 and 4 connectors of the fourth electronic four-way valve are connected, the 1 and 4 connectors of the first electronic four-way valve are connected, and the 1 and 4 connectors of the second electronic four-way valve are connected. The cooling fans of the first and second radiators are both stopped, and the second and third water pumps are infinitely variable in speed. If Te ≥ Tf, it indicates that the engine cooling water circuit has entered the overheating range. At this time, the 1 and 3 connectors of the second electronic four-way valve are connected, the 1 and 3 connectors of the third electronic four-way valve are connected, the cooling fan of the first radiator is infinitely variable in speed, and the second water pump is infinitely variable in speed.

[0017] Furthermore, in the VCU preset supercooling temperature step of step S1, a corresponding supercooling temperature is preset according to the operating conditions of each motor or controller.

[0018] Furthermore, if the motor set has a total of three motors: a first motor, a second motor, and a third motor, wherein the first motor and the second motor are connected in parallel and then connected in series with the third motor, then the preset subcooling temperature of the first motor and the second motor is TD1, and the corresponding acquisition temperatures are Td1 and Td2, respectively. The preset subcooling temperature of the third motor is TD2, and the corresponding acquisition temperature is Td3. The VCU compares and judges the acquisition temperature of each motor with the corresponding subcooling temperature one by one.

[0019] Furthermore, if the motor controller has a first controller and a second controller connected in series, the preset subcooling temperature of the first controller is TC1, and the corresponding acquisition temperature is Tc1; the preset subcooling temperature of the second controller is TC2, and the corresponding acquisition temperature is Tc2; the VCU compares and judges the acquisition temperature of each controller with the corresponding subcooling temperature one by one.

[0020] A hybrid excavator is equipped with any of the aforementioned hybrid engineering vehicle thermal management systems, and uses any of the aforementioned hybrid engineering vehicle thermal management methods to dynamically regulate the engine coolant circuit and the electrical component coolant circuit.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The hybrid engineering vehicle thermal management system of the present invention uses two circuits—an engine coolant circuit and an electrical component coolant circuit—to perform thermal management and regulation on the two power components of the hybrid system, respectively. Simultaneously, a fuel heating circuit is provided between the two circuits to provide auxiliary heating for the components in both circuits, enabling both cooling and heating, thus meeting the thermal management requirements under overheating and overcooling conditions. By switching the connection state of the electronic four-way valve between the two circuits, the engine coolant circuit can also preheat the electrical component coolant circuit, meeting the heating requirements of electrical components at low temperatures while saving energy. The hybrid engineering vehicle thermal management method of the present invention, based on the hybrid engineering vehicle thermal management system, performs real-time detection of components under low or high temperature conditions, and performs precise temperature control of the target water circuit through heaters or high-pressure electronic fans, realizing multiple regulation methods to ensure that the components operate at the most suitable temperature, thereby improving the adaptability of components to overcooling or overheating conditions and improving the overall reliability of the system; it also comprehensively judges the temperature of each component in the hybrid engineering vehicle thermal management system, avoiding misjudgments caused by a single judgment condition, and effectively improving the accuracy of the judgment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the connection structure of a thermal management system for a hybrid engineering vehicle according to the present invention.

[0023] Figure 2 This is a flowchart of a thermal management method for hybrid engineering vehicles according to the present invention.

[0024] in: 1. Fuel heater; 2. First three-way valve; 3. First water pump; 4. Second three-way valve; 5. First two-position four-way valve; 6. First electronic four-way valve; 7. Second electronic four-way valve; 8. First temperature sensor; 9. First radiator; 10. Third electronic four-way valve; 11. First high-pressure electronic fan; 12. Second water pump; 13. Engine; 14. ECU; 15. Third three-way valve; 16. Second controller; 17. First motor; 18. Second three-way valve; 19. First controller; 20. Third motor; 21. Third water pump; 22. Second radiator; 23. Second high-pressure electronic fan; 24. Second two-position four-way valve; 25. Second temperature sensor; 26. Fourth electronic four-way valve; 27. VCU; 28. Detailed Implementation Example 1

[0025] See Figure 1 The present invention relates to a thermal management system for a hybrid engineering vehicle, comprising an engine coolant circuit, an electrical component coolant circuit, a fuel heating circuit, and a vehicle controller VCU28; the VCU28 is electrically connected to each component in the engine coolant circuit, the electrical component coolant circuit, and the fuel heating circuit. The engine coolant circuit includes an engine 13, a second water pump 12, a second electronic four-way valve 7, a first radiator 9, and a third electronic four-way valve 10 connected in series with pipes at both ends. The engine 13 is equipped with an engine controller ECU 14 and a first temperature sensor 8. The ECU 14 is electrically connected to a VCU 28. The first temperature sensor 8 feeds back the engine coolant temperature to the ECU 14, and the ECU 14 then feeds back the engine coolant temperature to the VCU 28. The first radiator 9 is equipped with a first high-pressure electronic fan 11 for active cooling. The electrical component coolant circuit includes a motor controller, a motor set, a fourth electronic four-way valve 27, a second radiator 23, a first electronic four-way valve 6, and a third water pump 22 connected in series with pipes at both ends. A second temperature sensor 26 is provided on the pipe between the third water pump 22 and the fourth electronic four-way valve 27 to provide feedback on the electrical component coolant temperature to the VCU 28. The second radiator 23 is equipped with a second high-pressure electronic fan 24 for active cooling. In this embodiment, the motor set includes a first motor 17, a second motor 18, and a third motor 21. The first motor 17 and the second motor 18 are connected in parallel and then connected in series with the third motor 21. Specifically, the water inlets of the first motor 17 and the second motor 18 are split through a third three-way valve 15, and the water outlets are combined through a fourth three-way valve 19, thus achieving parallel connection in the electrical component coolant circuit. The motor controller includes a first controller 20 and a second controller 16 connected in series. The second controller 16 controls the first motor 17 and the second motor 18, which are connected in parallel to provide slewing power for the hybrid excavator. The first controller 20 controls the third motor 21, which is directly connected to the hydraulic pump of the hybrid excavator to drive the hydraulic pump. In other embodiments, a power battery pack can also be connected in series in the electrical component coolant circuit to improve the adaptability of the power battery pack to low-temperature environments. The first electronic four-way valve 6 and the second electronic four-way valve 7 are connected by pipelines; the third electronic four-way valve 10 and the fourth electronic four-way valve 27 are connected by pipelines. The fuel heating circuit includes a fuel heater 1, a first water pump 3 connected to the outlet of the fuel heater 1, and a first two-position four-way valve 5 and a second two-position four-way valve 25 connected in parallel to the inlet of the fuel heater 1 and the outlet of the first water pump 3. Specifically, the first two-position four-way valve 5 and the second two-position four-way valve 25 are connected in parallel to the circuit of the fuel heater 1 and the first water pump 3 through a second three-way valve 4 and a first three-way valve 2. The first two-position four-way valve 5 is connected to the second electronic four-way valve 7 and the third electronic four-way valve 10 of the engine coolant circuit, respectively. The second two-position four-way valve 25 is connected to the first electronic four-way valve 6 and the fourth electronic four-way valve 27 of the electrical component coolant circuit, respectively. The VCU28 controls the first two-position four-way valve 5 and the second two-position four-way valve 25 to close only one of the valves at the same time, and controls the four connectors of the first electronic four-way valve 6, the second electronic four-way valve 7, the third electronic four-way valve 10, and the fourth electronic four-way valve 27 to connect only two connectors at the same time.

[0026] The hybrid engineering vehicle thermal management system of the present invention uses two circuits—an engine coolant circuit and an electrical component coolant circuit—to perform thermal management and regulation on the two power components of the hybrid system, respectively. Simultaneously, a fuel heating circuit is provided between the two circuits to provide auxiliary heating for the components in both circuits, enabling both cooling and heating, thus meeting the thermal management requirements under overheating and overcooling conditions. By switching the connection state of the electronic four-way valve between the two circuits, the engine coolant circuit can also preheat the electrical component coolant circuit, meeting the heating requirements of electrical components at low temperatures while saving energy. Example 2

[0027] See Figure 2 The present invention relates to a thermal management method for hybrid engineering vehicles, which is implemented based on the thermal management system for hybrid engineering vehicles described in Embodiment 1. The specific operation steps include: S1. In VCU28, preset the superheat temperature Tg of the electrical component coolant and the superheat temperature Tf of the engine coolant. At the same time, preset the corresponding supercooling temperature TDn for each motor and the corresponding supercooling temperature TCm for each controller. Based on the three motors and two controllers set in Embodiment 1, namely the first motor 17, the second motor 18 and the third motor 21, the first controller 20 and the second controller 16, wherein the first motor 17 and the second motor 18 have the same operating conditions, so the same supercooling temperature TD1 is set. The third motor 21 is set with a corresponding supercooling temperature TD2. The first controller 20 is set with a corresponding supercooling temperature TC1, and the second controller 16 is set with a corresponding supercooling temperature TC2. S2. The VCU28 collects the coolant temperature in the engine coolant circuit and the electrical component coolant circuit, where Ta is the temperature collected by the second sensor 26, i.e., the coolant temperature in the electrical component coolant circuit, Tdn is the temperature collected by any motor in the motor set, Tcm is the temperature collected by any controller of the motor controller, and Te is the temperature collected by the engine 13. In this embodiment, the engine coolant circuit is referred to as the engine cooling water circuit, and the electrical component coolant circuit is referred to as the electrical component cooling water circuit. The collected temperatures of the first motor 17, the second motor 18, and the third motor 21 are Td1, Td2, and Td3, respectively; the collected temperatures of the first controller 20 and the second controller 16 are Tc1 and Tc2, respectively. S3 and VCU will analyze the collected temperature data layer by layer. First, based on the collected temperature Ta of the electrical component coolant circuit, they will determine and control the regulation actions of the entire thermal management system. S31. When Ta≥0, if Ta<Tg, it indicates that the temperature of the electrical component cooling water circuit is normal. At this time, the cooling fans of the fuel heater 1 and the second radiator 23 are both stationary and do not work. If Ta≥Tg, it indicates that the electrical component cooling water circuit has entered the overheating range. At this time, VCU28 controls the connection of connectors 1 and 3 of the first electronic four-way valve 6 and the connection of connectors 1 and 3 of the fourth electronic four-way valve 27. The second radiator 23 is connected in series to the electrical component cooling water circuit. At the same time, VCU28 controls the third water pump 22 to increase the pumping flow rate and the second high-pressure electronic fan 24 of the second radiator 23 to infinitely adjust the speed until Ta<Tg. S32. When Ta < 0, if Tdn < TDn, it means that the nth motor is in an extremely low temperature state and requires the fuel heater 1 to provide auxiliary heating to the electrical circuit. At this time, the second two-position four-way valve 25 is connected, the first electronic four-way valve 6's 1 and 2 connectors are connected, the fourth electronic four-way valve 27's 1 and 2 connectors are connected, the second radiator 23's cooling fan stops, and the third water pump 22's flow rate is infinitely adjustable. If Tdn ≥ TDn, then proceed to the next motor judgment operation. Repeat this step until all motors are processed, and then proceed to the next operation. Specifically: If Td1 < TD1, it means that the first motor 17 is in an extremely low temperature state and heating should be performed according to the above steps. If Td1 ≥ TD1, then further determine Td2. If Td2 < TD1, it means that the second motor 18 is in an extremely low temperature state and heating needs to be turned on. If Td2 ≥ TD1, then further determine Td3. If Td3 < TD2, it means that the third motor 21 is in an extremely low temperature state and heating needs to be turned on. If Td3 ≥ TD2, then proceed to the next step. S33. If Tcm < TCm, it means that the m-th controller is in an extremely low temperature state and the fuel heater 1 is required to provide auxiliary heating for the electrical circuit. At this time, VCU28 controls the fuel heating circuit and the electrical cooling water circuit to perform auxiliary heating according to the heating operation in step S32. If Tcm ≥ TCm, the judgment operation of the next controller is performed. This step is repeated until all controllers are processed, and then the next operation is performed. Specifically, if Tc1 < TC1, it means that the first controller 20 is in an extremely low temperature state and heating is performed according to the above steps. If Tc1 ≥ TC1, then Tc2 is further determined. If Tc2 < TC2, it means that the second controller 16 is in an extremely low temperature state and heating needs to be turned on. If Tc2 ≥ TC2, then proceed to the next step. S34. If Te≤0, it means that the engine cooling water circuit is in an overcooled state and requires the fuel heater 1 to assist in heating it. At this time, the first two-position four-way valve 5 is connected, the 1 and 2 connectors of the second electronic four-way valve 7 are connected, the 1 and 2 connectors of the third electronic four-way valve 10 are connected, the cooling fan of the first radiator 9 stops, and the second water pump 12 is infinitely adjustable. If Te>0, proceed to the next step. S35. If Te < Tf, it indicates that the engine cooling water circuit temperature is normal. At this time, the engine cooling water circuit assists in heating the electrical component cooling water circuit. At this time, the 1 and 4 connectors of the third electronic four-way valve 10 are connected, the 1 and 4 connectors of the fourth electronic four-way valve 27 are connected, the 1 and 4 connectors of the first electronic four-way valve 6 are connected, the 1 and 4 connectors of the second electronic four-way valve 7 are connected, the cooling fans of the first radiator 9 and the second radiator 23 are both stopped, and the second water pump 12 and the third water pump 22 are infinitely variable in speed. If Te ≥ Tf, it indicates that the engine cooling water circuit has entered the overheating range. At this time, the 1 and 3 connectors of the second electronic four-way valve 7 are connected, the 1 and 3 connectors of the third electronic four-way valve 10 are connected, the cooling fan of the first radiator 9 is infinitely variable in speed, and the second water pump 12 is infinitely variable in speed.

[0028] The hybrid engineering vehicle thermal management method of this invention realizes multiple control modes: fuel heater assists in heating the engine water circuit, fuel heater assists in heating the electrical water circuit, engine water circuit assists in heating the electrical water circuit, fuel heater and high-voltage electronic fan are stationary, the first high-voltage electronic fan is steplessly speed-regulated to cool the engine water circuit, and the second high-voltage electronic fan is steplessly speed-regulated to cool the electrical water circuit. For components under low or high temperature conditions, real-time detection is performed, and the target water circuit is precisely temperature-controlled through heaters or high-voltage electronic fans, so that the components work at the most suitable temperature, improving the adaptability of components to overcooling or overheating conditions and improving the overall reliability of the system. The temperature of each component in the hybrid engineering vehicle thermal management system is comprehensively judged, avoiding misjudgment caused by a single judgment condition, and effectively improving the accuracy of the judgment. Example 3

[0029] The present invention relates to a hybrid excavator equipped with the hybrid engineering vehicle thermal management system of Embodiment 1, and adopts the hybrid engineering vehicle thermal management method of Embodiment 2 to dynamically regulate the engine coolant circuit and the electrical component coolant circuit, effectively improving the start-up capability and continuous operation capability of the hybrid excavator in extremely low temperature environments, and avoiding economic losses caused by low temperature shutdowns.

[0030] Additionally, it should be noted that the above-described specific implementation is merely an optimized solution of this patent, and any modifications or improvements made by those skilled in the art based on the above concept are within the scope of protection of this patent.

Claims

1. A thermal management system for hybrid engineering vehicles, characterized in that: It includes an engine coolant circuit, an electrical component coolant circuit, a fuel heating circuit, and a vehicle control unit (VCU) (28); the VCU (28) is electrically connected to each component in the engine coolant circuit, the electrical component coolant circuit, and the fuel heating circuit; The engine coolant circuit includes an engine (13), a second water pump (12), a second electronic four-way valve (7), a first radiator (9), and a third electronic four-way valve (10) connected in series with pipes at both ends. The electrical component coolant circuit includes a motor controller, a motor set, a fourth electronic four-way valve (27), a second radiator (23), a first electronic four-way valve (6), and a third water pump (22) connected in series with the first and last pipes connected in series. The first electronic four-way valve (6) and the second electronic four-way valve (7) are connected by pipelines; the third electronic four-way valve (10) and the fourth electronic four-way valve (27) are connected by pipelines. The fuel heating circuit includes a fuel heater (1), a first water pump (3) connected to the outlet of the fuel heater (1), and a first two-position four-way valve (5) and a second two-position four-way valve (25) connected in parallel to the inlet of the fuel heater (1) and the outlet of the first water pump (3); the first two-position four-way valve (5) is connected to the pipelines of the second electronic four-way valve (7) and the third electronic four-way valve (10) of the engine coolant circuit respectively; the second two-position four-way valve (25) is connected to the pipelines of the first electronic four-way valve (6) and the fourth electronic four-way valve (27) of the electrical component coolant circuit respectively; The motor set includes a first motor (17), a second motor (18) and a third motor (21), wherein the first motor (17) and the second motor (18) are connected in parallel and then connected in series with the third motor (21); the water inlets of the first motor (17) and the second motor (18) are diverted through the third three-way valve (15) and the water outlets are merged through the fourth three-way valve (19), thus achieving parallel connection in the electrical component coolant circuit; the first two-position four-way valve (5) and the second two-position four-way valve (25) are connected in parallel in the fuel heating circuit through the second three-way valve (4) and the first three-way valve (2).

2. The hybrid engineering vehicle thermal management system according to claim 1, characterized in that: The motor controller includes a first controller (20) and a second controller (16) connected in series, which respectively control the driving of different motors.

3. The hybrid engineering vehicle thermal management system according to claim 1, characterized in that: The engine (13) is equipped with an engine controller ECU (14) and a first temperature sensor (8), and the ECU (14) is electrically connected to the VCU (28).

4. The hybrid engineering vehicle thermal management system according to claim 1, characterized in that: The electrical component coolant circuit is equipped with a second temperature sensor (26) that is electrically connected to the VCU (28).

5. The hybrid engineering vehicle thermal management system according to claim 1, characterized in that: The cooling fans of the first heat sink (9) and the second heat sink (23) are high-voltage electronic fans, and the two heat sinks are respectively equipped with a first high-voltage electronic fan (11) and a second high-voltage electronic fan (24).

6. The hybrid engineering vehicle thermal management system according to claim 1, characterized in that: The VCU (28) controls the first two-position four-way valve (5) and the second two-position four-way valve (25) to close only one valve at the same time, and controls the four connectors of the first electronic four-way valve (6), the second electronic four-way valve (7), the third electronic four-way valve (10), and the fourth electronic four-way valve (27) to connect only two connectors at the same time.

7. A thermal management method for hybrid engineering vehicles, characterized in that: It is implemented based on any one of the hybrid engineering vehicle thermal management systems of claims 1 to 6, and the specific operation steps include: S1. In VCU (28), preset the overheating temperature Tg of the electrical component coolant and the overheating temperature Tf of the engine coolant, and at the same time, preset the corresponding overcooling temperature TDn for each motor and the corresponding overcooling temperature TCm for each controller. S2, the VCU (28) collects the coolant temperature in the engine coolant circuit and the electrical component coolant circuit, where Ta is the coolant temperature collected in the electrical component coolant circuit, Tdn is the temperature collected by any motor in the motor group, Tcm is the temperature collected by any controller of the motor controller, and Te is the temperature collected by the engine (13). S3 and VCU will analyze the collected temperature data layer by layer. First, based on the collected temperature Ta of the electrical component coolant circuit, they will determine and control the regulation actions of the entire thermal management system. S31. When Ta≥0, if Ta<Tg, it means that the temperature of the electrical component cooling water circuit is normal. At this time, the cooling fans of the fuel heater (1) and the second radiator (23) are both stationary and do not work. If Ta≥Tg, it means that the electrical component cooling water circuit has entered the overheating range. At this time, the VCU (28) controls the connection of the 1 and 3 connectors of the first electronic four-way valve (6), the connection of the 1 and 3 connectors of the fourth electronic four-way valve (27), and the second radiator (23) is connected in series to the electrical component cooling water circuit. At the same time, the VCU (28) controls the third water pump (22) to increase the pumping flow rate and the second radiator (23) cooling fan to infinitely adjust the speed until Ta<Tg. S32. When Ta < 0, if Tdn < TDn, it means that the nth motor is in an extremely low temperature state and needs the fuel heater (1) to provide auxiliary heating for the electrical circuit. At this time, the second two-position four-way valve (25) is connected, the 1 and 2 connectors of the first electronic four-way valve (6) are connected, the 1 and 2 connectors of the fourth electronic four-way valve (27) are connected, the cooling fan of the second radiator (23) stops, and the flow of the third water pump (22) is infinitely adjustable. If Tdn ≥ TDn, the next motor judgment operation is performed. This step is repeated until all motors are processed, and then the next operation is performed. S33. If Tcm < TCm, it means that the m-th controller is in an extremely low temperature state and the fuel heater (1) is needed to provide auxiliary heating for the electrical circuit. At this time, the VCU (28) controls the fuel heating circuit and the electrical cooling water circuit to provide auxiliary heating according to step S32. If Tcm ≥ TCm, the judgment operation of the next controller is performed. This step is repeated until all controllers are processed, and then the next operation is performed. S34. If Te≤0, it means that the engine cooling water circuit is in an overcooled state and requires the fuel heater (1) to assist in heating it. At this time, the first two-position four-way valve (5) is connected, the 1 and 2 connectors of the second electronic four-way valve (7) are connected, the 1 and 2 connectors of the third electronic four-way valve (10) are connected, the cooling fan of the first radiator (9) stops, and the second water pump (12) is infinitely adjustable. If Te>0, proceed to the next step. S35. If Te < Tf, it means that the engine cooling water circuit temperature is normal. At this time, the engine cooling water circuit assists in heating the electrical component cooling water circuit. At this time, the 1 and 4 connectors of the third electronic four-way valve (10) are connected, the 1 and 4 connectors of the fourth electronic four-way valve (27) are connected, the 1 and 4 connectors of the first electronic four-way valve (6) are connected, the 1 and 4 connectors of the second electronic four-way valve (7) are connected, the cooling fans of the first radiator (9) and the second radiator (23) are stopped, and the second water pump (12) and the third water pump (22) are infinitely variable in speed. If Te ≥ Tf, it means that the engine cooling water circuit has entered the overheating range. At this time, the 1 and 3 connectors of the second electronic four-way valve (7) are connected, the 1 and 3 connectors of the third electronic four-way valve (10) are connected, the cooling fan of the first radiator (9) is infinitely variable in speed, and the second water pump (12) is infinitely variable in speed.

8. The thermal management method for hybrid engineering vehicles according to claim 7, characterized in that: In the VCU (28) preset supercooling temperature step in step S1, the corresponding supercooling temperature is preset according to the operating conditions of each motor or controller.

9. The thermal management method for hybrid engineering vehicles according to claim 7, characterized in that: If the motor set has a total of three motors: the first motor (17), the second motor (18) and the third motor (21), wherein the first motor (17) and the second motor (18) are connected in parallel and then connected in series with the third motor (21), then the preset supercooling temperature of the first motor (17) and the second motor (18) is TD1, and the corresponding acquisition temperatures are Td1 and Td2 respectively, and the preset supercooling temperature of the third motor (21) is TD2, and the corresponding acquisition temperature is Td3; the VCU compares and judges the acquisition temperature of each motor with the corresponding supercooling temperature one by one.

10. The thermal management method for hybrid engineering vehicles according to claim 7, characterized in that: If the motor controller has a first controller (20) and a second controller (16) connected in series, the preset subcooling temperature of the first controller (20) is TC1, and the corresponding acquisition temperature is Tc1. The preset subcooling temperature of the second controller (16) is TC2, and the corresponding acquisition temperature is Tc2. The VCU compares and judges the acquisition temperature of each controller with the corresponding subcooling temperature one by one.

11. A hybrid excavator, characterized in that: The vehicle is equipped with a thermal management system of any one of claims 1 to 6, and uses a thermal management method of any one of claims 7 to 10 to dynamically regulate the engine coolant circuit and the electrical component coolant circuit.

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