A thermal management system for an all-electric excavator

Abstract

The utility model provides a kind of pure electric excavator thermal management system, including motor cooling module, power battery cooling module and hydraulic oil cooling module, hydraulic oil cooling module includes hydraulic oil tank and radiator, and hydraulic oil tank is communicated with radiator and forms first closed loop, and radiator is connected with fan and condenser in turn;Power battery cooling module includes power battery, heat exchanger, compressor, and power battery is connected with heat exchanger and forms second closed loop, and heat exchanger is connected with compressor and condenser in turn and forms third closed loop, and motor cooling module includes first water pump, motor controller and motor connected in turn, and motor cooling module is connected with radiator to form fourth closed loop, and motor cooling module, power battery cooling module and hydraulic oil cooling module three cooling modules form collaborative working relationship, in solving the energy consumption of each cooling system independent control resulting in too high, improve pure electric excavator thermal management system energy efficiency, also can solve the heat dissipation coordination problem of motor, power battery, hydraulic system in the operation process of pure electric excavator.

Description

Technical Field

[0001] This utility model relates to the field of thermal management technology for pure electric excavators, and in particular to a thermal management system for pure electric excavators. Background Technology

[0002] Excavators, as an important type of engineering machinery, are widely used in various fields such as infrastructure construction, mining, and agricultural water conservancy. In recent years, driven by both environmental protection and technological innovation, electric excavators have rapidly become popular in the field of engineering machinery, especially in the mining industry where routes are fixed and centralized charging conditions are well-established. However, electric excavators require a large number of high-capacity power batteries to provide power. High-power battery packs generate a lot of heat during high-current charging and discharging, which affects the battery's power. In addition, electric excavators operate under high loads and continuously in harsh environments with high temperatures and high dust levels year-round, making heat dissipation an extremely critical and challenging issue.

[0003] The existing thermal management system of electric excavators basically consists of three parts: the motor cooling system, the power battery cooling system, and the hydraulic oil cooling system. These three cooling systems adopt an independent cooling operation mode, with each subsystem managing a different heat source. This results in complex internal piping and excessive energy consumption. In addition, due to the lack of effective coordinated control between the motor, power battery, and hydraulic system during the operation of pure electric excavators, each of the three independent cooling systems requires its own radiator, fan, piping, and other components. This not only increases the difficulty of spatial layout but may also lead to interference between components, affecting the overall structural compactness and reliability of the equipment and causing inconvenience for subsequent maintenance and repair. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this utility model provides a thermal management system for a pure electric excavator. This utility model eliminates the independent thermal management scheme. The three heat dissipation modules—motor heat dissipation module, power battery cooling module, and hydraulic oil heat dissipation module—form a collaborative working relationship. While solving the problem of excessive energy consumption caused by independent control of each heat dissipation system and improving the energy efficiency of the thermal management system of the pure electric excavator, it also further reduces the cost and spatial layout difficulty of the pure electric excavator unit.

[0005] To achieve the above objectives, one or more embodiments of this utility model provide the following technical solutions: A thermal management system for a pure electric excavator includes a motor cooling module, a power battery cooling module, and a hydraulic oil cooling module. The hydraulic oil cooling module includes a hydraulic oil tank and a radiator. The hydraulic oil tank and the radiator are connected to form a first closed loop. The radiator is connected in sequence to a fan and a condenser.

[0006] The power battery cooling module includes a power battery, a heat exchanger, and a compressor. The power battery and the heat exchanger are connected in series to form a second closed loop. The heat exchanger is also connected in sequence to the compressor and the condenser to form a third closed loop.

[0007] The motor cooling module includes a first water pump, a motor controller, and a motor connected in sequence. The motor cooling module is connected to a radiator to form a fourth closed loop. The fourth closed loop shares a radiator with the first closed loop. The radiator of the first closed loop shares a fan with the condenser of the third closed loop.

[0008] Furthermore, the outlet of the first water pump is connected to the inlet of the motor controller, the outlet of the motor controller is connected to the inlet of the motor, the outlet of the motor is connected to the coolant side inlet of the radiator through a pipeline, and the coolant side outlet of the radiator flows back to the first water tank through a pipeline.

[0009] Furthermore, the motor cooling module also includes a first water supply tank and a first degassing pipe. The first water supply tank is connected to the first water pump, and one end of the first degassing pipe is connected to the first water supply tank, while the other end is connected to the pipeline of the motor cooling module.

[0010] Furthermore, the second closed loop is also equipped with a second water pump and a first temperature sensor. The second water pump is located between the power battery and the heat exchanger, and the first temperature sensor is installed on the return pipeline between the heat exchanger and the power battery. There are two of them, which are respectively located on the pipelines on the inlet side and the outlet side of the power battery.

[0011] Furthermore, the power battery is connected to the inlet of the second water pump via a water pipe, the second water pump is connected to the inlet side of the heat exchanger via a pipe, and the water from the outlet side of the heat exchanger flows back to the inlet of the power battery via a water pipe to form a second closed loop.

[0012] Furthermore, the power battery cooling module also includes a second water tank and a second degassing pipe. One end of the second water tank is connected to the second water pump, and one end of the second degassing pipe is connected to the second water tank. The other end is connected to the pipeline of the second closed loop, and the connection point is located between the power battery and the heat exchanger and close to the power battery.

[0013] Furthermore, a thermal expansion valve is also provided on the third closed loop, and the thermal expansion valve is located on the connecting pipe between the condenser and the radiator.

[0014] Furthermore, the first closed loop is also equipped with a hydraulic oil pump and a second temperature sensor. The hydraulic oil pump is installed on the pipeline connecting the radiator and the hydraulic oil tank, and the second temperature sensor is installed on the return pipeline between the radiator and the hydraulic oil tank. There are two of them, which are respectively installed on the loop pipelines on the inlet side and the outlet side of the radiator.

[0015] Furthermore, the second closed loop uses ordinary water pipes, and the third closed loop uses refrigerant pipes.

[0016] Furthermore, the fan is a gaseous refrigerant fan.

[0017] Compared with the prior art, this utility model has at least the following advantages and beneficial effects: 1. This utility model eliminates the independent thermal management scheme. The three heat dissipation modules—motor heat dissipation module, power battery cooling module, and hydraulic oil heat dissipation module—can each form an independent closed-loop heat dissipation circuit, but they are not completely independent. The above three heat dissipation modes share a common heat dissipation structure. That is, the fourth closed loop and the first closed loop share a radiator, and the heat exchanger of the first closed loop and the condenser of the third closed loop share a fan. The three heat dissipation modes are both independent and cooperative in heat dissipation. While solving the problem of excessive energy consumption caused by independent control of each heat dissipation system and improving the energy efficiency of the thermal management system of pure electric excavators, it also further reduces the cost of pure electric excavator units and the difficulty of space layout.

[0018] 2. The power battery adopts a two-stage liquid cooling system, and the motor and hydraulic oil share the same radiator. This allows for the reasonable distribution and coordinated heat dissipation of heat based on the hydraulic oil temperature at the radiator outlet, the motor controller temperature, and the power battery temperature.

[0019] Advantages of the present invention in additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0021] Figure 1 This is a schematic diagram of the thermal management system for a pure electric excavator according to this utility model; The components are as follows: 1. Hydraulic oil tank; 2. Radiator; 3. First closed loop; 4. Fan; 5. Condenser; 6. Hydraulic oil pump; 7. First temperature sensor; 8. Second temperature sensor; 9. Power battery; 10. Heat exchanger; 11. Compressor; 12. Second closed loop; 13. Second water pump; 14. Second degassing pipe; 15. Third closed loop; 16. Thermal expansion valve; 17. First water pump; 18. Motor controller; 19. Motor; 20. Fourth closed loop; 21. First water supply tank; 22. Second water supply tank; 23. First degassing pipe. Detailed Implementation

[0022] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention.

[0023] Where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0024] Example 1: like Figure 1 As shown, this embodiment provides a thermal management system for a pure electric excavator, including a motor cooling module, a power battery cooling module, and a hydraulic oil cooling module. The hydraulic oil cooling module includes a hydraulic oil tank 1 and a radiator 2. The hydraulic oil tank 1 and the radiator 2 are connected to form a first closed loop 3. The radiator is also connected in sequence to a fan 4 and a condenser 5.

[0025] A fan 4 and a condenser 5 are sequentially installed on the air outlet side of the radiator. The fan is located between the radiator and the condenser. The fan uses a gaseous refrigerant fan, which can assist in heat dissipation through the flow of refrigerant. A hydraulic oil pump 6 and a second temperature sensor 8 are also installed on the first closed loop. The hydraulic oil pump 6 is installed on the pipeline connecting the radiator and the hydraulic oil tank. The oil outlet of the hydraulic oil tank 1 is connected to the inlet of the hydraulic oil pump through a pipeline. The outlet of the hydraulic oil pump 6 is connected to the oil inlet of the radiator 2. The oil outlet of the radiator flows back to the hydraulic oil tank 1 through the pipeline via the hydraulic oil pump 6, forming the first closed loop, namely the hydraulic oil heat dissipation circulation loop.

[0026] The second temperature sensor 8 is installed on the return pipeline between the radiator and the hydraulic oil tank. There are two of them. These two second temperature sensors are respectively installed on the pipelines on the inlet side and the outlet side of the radiator 2. The hydraulic oil temperature on the inlet side and the outlet side of the radiator can be monitored in real time through the second temperature sensors.

[0027] When the hydraulic oil temperature is too high during operation, the hydraulic oil pump is turned on to make the hydraulic oil cooling module of this embodiment circulate. The high temperature hydraulic oil in the hydraulic oil tank 1 enters the pipeline of the first closed loop 3 and enters the radiator under the drive of the hydraulic oil pump. The heat of the high temperature hydraulic oil is carried away by the cooling effect of the gaseous refrigerant fan.

[0028] The power battery cooling module includes a power battery 9, a heat exchanger 10, and a compressor 11. The power battery and the heat exchanger are connected in series to form a second closed loop 12. The second closed loop 12 uses ordinary water pipes. A second water pump 13 and a first temperature sensor 7 are also installed on the second closed loop. The second water pump is located between the power battery and the heat exchanger. Specifically, the power battery is connected to the inlet of the second water pump through an ordinary water pipe, and the second water pump 13 is connected to the inlet side of the heat exchanger through a pipe. The outlet side of the heat exchanger returns to the inlet of the power battery through an ordinary water pipe to form the second closed loop. There are two first temperature sensors 7, which are respectively installed on the pipes on the inlet side and the outlet side of the power battery. The temperature of the coolant in the second closed loop can be detected in real time by the first temperature sensors 7.

[0029] The heat exchanger 10 in the second closed loop 12 is also connected to the compressor 11 and the condenser 5 to form a third closed loop 15. The piping of the third closed loop uses refrigerant pipes, and the refrigerant liquid circulating in the refrigerant pipes is a 50% ethylene glycol aqueous solution. A thermostatic expansion valve 16 is also installed on the third closed loop. The thermostatic expansion valve 16 is specifically installed on the connecting pipe between the condenser 5 and the heat exchanger 10. The thermostatic expansion valve maintains the third closed loop in a constant optimal working state, that is, maintains a constant superheat to ensure efficient heat exchange. Specifically, the heat exchanger is connected to the compressor inlet through the refrigerant pipe, the compressor outlet is connected to the condenser inlet, the condenser outlet is connected to the thermostatic expansion valve inlet through the refrigerant pipe, and the thermostatic expansion valve outlet is connected to the heat exchanger inlet, forming the third closed loop.

[0030] When the power battery has a cooling requirement, the second water pump drives the cooling water in the second closed loop to circulate. When the water in the second closed loop flows through the heat exchanger, it exchanges heat with the refrigerant liquid in the refrigerant pipeline of the third closed loop, thereby cooling down the cooling water in the second closed loop. After the cooling water is cooled down at the heat exchanger, it flows back to the power battery along the circulation pipeline and then cools down the power battery through the heat exchange principle.

[0031] When the power battery requires cooling, the compressor 11 in the third closed loop starts simultaneously with the second water pump. The refrigerant liquid circulates in the third closed loop, and is compressed into a high-temperature, high-pressure gaseous refrigerant by the compressor and enters the condenser. The fan shared with the hydraulic oil cooling module accelerates the cooling of the refrigerant, causing it to condense into a low-temperature, high-pressure liquid refrigerant. Then, with the throttling effect of the thermostatic expansion valve, it is transformed into a low-temperature, low-pressure mist refrigerant. The low-temperature, low-pressure mist refrigerant enters the heat exchanger along the third closed loop and exchanges heat with the coolant in the second loop to reduce the coolant temperature, ultimately cooling the power battery.

[0032] The motor cooling module is connected in series with the first water pump 17, the motor controller 18, and the motor 19. The motor cooling module is connected to the radiator to form a fourth closed loop 20. The fourth closed loop 20 shares a radiator 2 with the first closed loop 3. The radiator 2 of the first closed loop 3 shares a fan 4 with the condenser of the third closed loop 15. Specifically, the outlet of the first water pump is connected to the inlet of the motor controller 18, the outlet of the motor controller is connected to the inlet of the motor, the outlet of the motor is connected to the coolant inlet of the radiator through a pipeline, and the coolant outlet of the radiator flows back to the first water tank through a pipeline, forming the fourth closed loop.

[0033] When the motor or motor controller overheats, the first water pump drives the cooling water in the first closed loop to circulate. When the cooling water flows through the radiator, the fan carries away the heat and turns it into cold water. The cold water then flows back to the motor and motor controller to dissipate the heat of the structure, thus achieving heat dissipation for the motor and motor controller.

[0034] Considering that the second and fourth closed loops in this embodiment will consume some water during the heat dissipation rotation process, the motor heat dissipation module in this embodiment includes a first water tank 21, and the power battery cooling module includes a second water tank 22. The first water tank 21 is positioned higher than the first water pump 17 and is connected to the first water pump. The second water tank 22 is positioned higher than the second water pump and is connected to the second water pump. The first and second water tanks are used to replenish the cooling water lost during the corresponding closed loop circulation process.

[0035] Furthermore, since the gas contained in the cooling liquid can affect the smoothness of the corresponding closed loop, this embodiment provides a first degassing pipe 23 in the motor heat dissipation module. One end of the first degassing pipe is connected to the first water tank, and the other end is connected to the pipeline of the motor heat dissipation module. A second degassing pipe 14 is provided in the power battery cooling module. One end of the second degassing pipe is connected to the second water tank, and the other end is connected to the pipeline of the second closed loop. The first and second degassing pipes can remove the gas that may be generated in the corresponding closed loop during the circulation process to ensure the cooling effect. Air in the cooling water is released under the action of water pump operation and water heating and cooling. These bubbles move in the pipe with the water flow. Since the degassing pipe is usually connected to the highest point of the water tank, according to the characteristic of bubbles rising upwards, the gas enters the expansion tank through the upwardly inclined degassing pipe and is discharged through the exhaust valve in the tank.

[0036] The three heat dissipation modules in this embodiment have two operating modes, namely, whether or not a battery cooling signal is present. In this embodiment, the battery cooling signal is equivalent to whether the battery needs to be cooled. The duty cycle, i.e., the speed, of the fan can be changed according to the different outlet hydraulic oil of the radiator and the current temperature of the motor controller. 1. When there is no battery cooling signal: a. When the hydraulic oil temperature at the radiator outlet is 45°C, the fan provides a 30% duty cycle rotation. When the hydraulic oil temperature at the radiator outlet is 50°C, the fan provides an 80% duty cycle rotation. When the hydraulic oil temperature at the radiator outlet is between 45°C and 50°C, linear speed regulation is used. When the hydraulic oil temperature at the radiator outlet is 53°C, the fan provides a 95% duty cycle rotation.

[0037] b. When the motor controller temperature is 50℃, the fan operates at a 30% duty cycle; when the motor controller temperature is 60℃, the fan operates at an 80% duty cycle; when the motor controller temperature is between 50℃ and 60℃, linear speed regulation is used. When the motor controller temperature is 63℃, the fan operates at a 95% duty cycle.

[0038] c. When the motor temperature is 65℃, the fan provides a 30% duty cycle rotation; when the motor temperature is 100℃, the fan provides an 80% duty cycle rotation; when the motor temperature is between 65℃ and 100℃, linear speed regulation is used. When the motor temperature is 110℃, the fan provides a 95% duty cycle rotation.

[0039] d. When the radiator inlet hydraulic oil temperature is 64°C, the fan provides a 95% duty cycle.

[0040] e. Priority is given to those who arrive first.

[0041] 2. When a battery cooling signal is present, the power battery has a cooling requirement. When the power battery temperature is between 25-35℃, the refrigerant cooled by the condenser is replaced by coolant through the plate heat exchanger for further cooling. At this time, the fan operates at a 60% duty cycle. When the motor or motor controller has a heat dissipation requirement, the fan's duty cycle directly increases from 60% to 80%. Only when the motor controller temperature reaches 63℃ or the motor temperature reaches 110℃ does the fan operate at a 95% duty cycle.

[0042] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A thermal management system for a pure electric excavator, characterized in that, It includes a motor cooling module, a power battery cooling module, and a hydraulic oil cooling module. The hydraulic oil cooling module includes a hydraulic oil tank and a radiator. The hydraulic oil tank and the radiator are connected to form a first closed loop. The radiator is connected to a fan and a condenser in sequence. The power battery cooling module includes a power battery, a heat exchanger, and a compressor. The power battery and the heat exchanger are connected in series to form a second closed loop. The heat exchanger is then connected in sequence to the compressor and the condenser to form a third closed loop. The motor cooling module includes a first water pump, a motor controller, and a motor connected in sequence. The motor cooling module is connected to a radiator to form a fourth closed loop. The fourth closed loop shares a radiator with the first closed loop. The radiator of the first closed loop shares a fan with the condenser of the third closed loop.

2. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The outlet of the first water pump is connected to the inlet of the motor controller, the outlet of the motor controller is connected to the inlet of the motor, the outlet of the motor is connected to the coolant side inlet of the radiator through a pipeline, and the coolant side outlet of the radiator flows back to the first water tank through a pipeline.

3. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The motor cooling module also includes a first water supply tank and a first degassing pipe. The first water supply tank is connected to the first water pump, and one end of the first degassing pipe is connected to the first water supply tank, while the other end is connected to the pipeline of the motor cooling module.

4. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The second closed loop is also equipped with a second water pump and a first temperature sensor. The second water pump is located between the power battery and the heat exchanger. The first temperature sensor is installed on the return pipeline between the heat exchanger and the power battery. There are two of them, which are respectively located on the inlet side and the outlet side of the power battery loop pipeline.

5. The thermal management system for a pure electric excavator as described in claim 4, characterized in that, The power battery is connected to the inlet of the second water pump via a water pipe. The second water pump is connected to the inlet side of the heat exchanger via a pipe. The water from the outlet side of the heat exchanger flows back to the inlet of the power battery via a water pipe, forming a second closed loop.

6. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The power battery cooling module also includes a second water tank and a second degassing pipe. One end of the second water tank is connected to the second water pump, and one end of the second degassing pipe is connected to the second water tank. The other end is connected to the pipeline of the second closed loop. The connection point is located between the power battery and the heat exchanger and close to the power battery.

7. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, A thermal expansion valve is also provided on the third closed loop, and the thermal expansion valve is located on the connecting pipe between the condenser and the radiator.

8. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The first closed loop is also equipped with a hydraulic oil pump and a second temperature sensor. The hydraulic oil pump is installed on the pipeline connecting the radiator and the hydraulic oil tank, and the second temperature sensor is installed on the return pipeline between the radiator and the hydraulic oil tank. There are two of them, which are respectively installed on the loop pipelines on the inlet side and the outlet side of the radiator.

9. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The second closed loop uses ordinary water pipes, and the third closed loop uses refrigerant pipes.

10. The thermal management system for a pure electric excavator as described in claim 1, characterized in that, The fan is a gaseous refrigerant fan.

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