A heat dissipation system for an electric excavator and an electric excavator

Abstract

The utility model provides a kind of heat dissipation system and electric excavator for electric excavator belongs to engineering instrument field, it solves the problem of insufficient radiator heat dissipation in high temperature environment, can satisfy the heat dissipation demand of motor and motor controller under high temperature environment, and its technical scheme is: including radiator, battery thermal management system and water-water plate exchange;The water outlet and water inlet of the radiator are connected with first cooling circulation pipeline;The battery thermal management system includes water-cooled unit;Second cooling liquid circulation pipeline is connected on the both sides of the water-cooled unit, and electronic three-way valve is respectively arranged on the second cooling liquid circulation pipeline of the both sides of the water-cooled unit;Two electronic three-way valves are communicated by third cooling circulation pipeline;The third cooling circulation pipeline and first cooling circulation pipeline are connected by water-water plate exchange;First cooling circulation pipeline exchanges heat with motor and motor controller.

Description

Technical Field

[0001] This utility model belongs to the field of engineering machinery, and in particular relates to a heat dissipation system for an electric excavator and an electric excavator. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Currently, the motor and motor controller are connected to the radiator in series or parallel for heat dissipation. This method can indeed meet the operating requirements of electric excavators at normal temperatures. The radiator can meet the operating environment temperature below 55℃, but it cannot meet the heat dissipation requirements when the ambient temperature exceeds 55℃.

[0004] In areas with extreme summer temperatures (such as deserts and tropical climates), the ambient temperature can reach over 40°C. Hot air continuously enters the tunnel entrance, and especially when ventilation is poor, heat easily accumulates inside, gradually raising the internal temperature. Some tunnels pass through geologically active areas or deep rock strata where the underground soil and rock temperatures are high (such as in hot spring areas or volcanic rock distribution areas). This continuously releases heat into the tunnel through the tunnel walls, creating a "geothermal heating" effect, which is particularly prevalent in long or deeply buried tunnels. Furthermore, when vehicles (especially trucks and construction vehicles) pass densely inside the tunnel, their engines release a large amount of waste heat, with exhaust temperatures reaching 300-500°C, continuously releasing heat into the tunnel. Simultaneously, friction between vehicle tires and the ground generates frictional heat, further contributing to the heat source. Due to all these factors, the high temperature environment inside tunnels can reach 60°C or even higher. In such a high-temperature environment (above 55℃), the heat exchange temperature difference between the ambient temperature and the required radiator outlet water temperature is small, resulting in a reduction in radiator heat dissipation and excessively high outlet water temperature. Existing heat dissipation methods using radiators cannot meet the heat dissipation requirements, which in turn leads to problems such as torque and power limitations in the motor controller and motor, affecting the overall working efficiency of the machine. Utility Model Content

[0005] To address at least one of the technical problems mentioned above, the first aspect of this utility model provides a cooling system for electric excavators. This system installs two electronic three-way valves on the existing battery thermal management system to draw out the coolant from the water-cooled unit. The coolant from the battery thermal management system is then exchanged with the coolant from the motor's cooling system via a water-to-water heat exchanger. This allows the excavator to meet the cooling requirements of the motor and motor controller even in high-temperature tunnel working environments exceeding 55°C, preventing overheating of the motor and damage that could affect the overall operation of the machine.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A cooling system for an electric excavator includes: a radiator, a battery thermal management system, and a water-cooled heat exchanger. The outlet and inlet of the radiator are connected to the first cooling circulation pipeline; The battery thermal management system includes a water-cooled unit with second coolant circulation pipelines connected to both sides of the water-cooled unit, and electronic three-way valves are respectively installed on the second coolant circulation pipelines on both sides of the water-cooled unit. The two electronic three-way valves are connected via a third cooling circulation pipe; The third cooling circulation pipeline and the first cooling circulation pipeline are connected by a water-to-water heat exchanger; The first cooling circulation pipeline exchanges heat with the motor and motor controller.

[0007] In one embodiment, the first cooling circulation pipeline includes a first coolant outlet pipe and a first coolant return pipe; The outlet of the radiator is connected to the first coolant outlet pipe, and the inlet of the radiator is connected to the first coolant return pipe.

[0008] In one implementation, a water pump is installed on the first coolant outlet pipe.

[0009] In one embodiment, the battery thermal management system further includes a battery pack, and the second cooling circulation pipeline exchanges heat with the battery pack.

[0010] In one embodiment, the water-cooled heat exchanger includes a first outlet, a first inlet, a second outlet, and a second inlet; the first coolant outlet pipe is connected to the first inlet of the water-cooled heat exchanger, and the first outlet of the water-cooled heat exchanger is connected to the first coolant return pipe.

[0011] In one embodiment, the third cooling circulation pipeline includes a third coolant outlet pipe and a third coolant return pipe; The first electronic three-way valve is connected to the second inlet of the water pump via the third coolant outlet pipe, and the second outlet of the water pump is connected to the second electronic three-way valve via the third coolant return pipe.

[0012] In one embodiment, a first temperature sensor is provided on the first coolant outlet pipe; the first temperature sensor is located on the first inlet side of the water exchanger. A second temperature sensor is installed on the first coolant outlet pipe; the second temperature sensor is located on the first outlet side of the water exchanger.

[0013] In one implementation, the first temperature sensor and the second temperature sensor communicate with the controller, respectively.

[0014] In one implementation, the first electronic three-way valve and the second electronic three-way valve communicate with the controller, respectively.

[0015] To address the aforementioned problems, a second aspect of this utility model provides an electric excavator that employs a cooling system for electric excavators as described in the first aspect for heat dissipation.

[0016] The advantage of the above solution is that, for high-temperature operating environments, no additional cooling system is required; the existing battery thermal management system of the electric excavator is used to cool the motor and motor controller.

[0017] The beneficial effects of this utility model are: 1. This utility model utilizes the additional cooling capacity of the battery thermal management system to dissipate heat from the motor and motor controller in high-temperature environments, solving the problem of insufficient heat dissipation from radiators in high-temperature environments and meeting the heat dissipation requirements of the motor and motor controller in high-temperature environments.

[0018] 2. This utility model installs two electronic three-way valves on the original battery thermal management system to draw out the coolant from the water-cooled unit, and then exchanges heat between the coolant of the battery thermal management system and the motor cooling system through a water-to-water heat exchanger. This allows the excavator to still meet the heat dissipation requirements of the motor and motor controller in the high-temperature tunnel working environment of more than 55°C, preventing the motor from overheating and causing damage, which would affect the operation of the whole machine.

[0019] 3. In the entire heat dissipation system of this utility model, only the battery thermal management system involves refrigerant (R134a), and the water coupling part of the radiator only involves water coupling. The reliability of the system is improved. By solving the heat dissipation problem in high-temperature environments, the operating temperature range of the whole machine is increased, and the application scope is broadened. Under different temperature differences, the power of the electronic three-way valve and the water-cooled unit can be controlled, which is more energy-efficient.

[0020] 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

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the overall structure of a heat dissipation system for an electric excavator according to this utility model; Figure 2 This is a front view of the water-plate replacement structure of this utility model.

[0023] Figure 3 This is a side view of the water-water plate replacement structure of this utility model.

[0024] Among them, 1. Radiator, 2. Water-cooled unit, 3. Water-to-water heat exchanger, 311. First outlet, 312. First inlet, 321. Second outlet, 322. Second inlet, 33. Metal plate, 4. Battery pack, 5. Motor, 6. Motor controller, 71. First temperature sensor, 72. Second temperature sensor, 81. First electronic three-way valve, 82. Second electronic three-way valve, 8. First circulation pipeline, 9. Second circulation pipeline, 10. Third circulation pipeline, 11. Water pump. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed description is illustrative 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.

[0027] 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. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] In this utility model, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0029] In this utility model, terms such as "fixed connection," "connected," and "joined" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0030] Example 1 This embodiment discloses a cooling system for an electric excavator, including: a radiator, a battery thermal management system, and a water-to-water heat exchanger; the radiator's outlet and inlet are connected to a first cooling circulation pipeline; the battery thermal management system includes a water-cooled unit, with second coolant circulation pipelines connected to both sides of the water-cooled unit, and electronic three-way valves respectively installed on the second coolant circulation pipelines on both sides of the water-cooled unit; the two electronic three-way valves are connected through a third cooling circulation pipeline; the third cooling circulation pipeline and the first cooling circulation pipeline are connected through a water-to-water heat exchanger; the first cooling circulation pipeline exchanges heat with the motor and motor controller. The first cooling circulation pipeline includes a first coolant outlet pipe and a first coolant return pipe; the radiator's outlet is connected to the first coolant outlet pipe, and the radiator's inlet is connected to the first coolant return pipe. Figure 2 As shown, the water-cooled heat exchanger includes a first outlet, a first inlet, a second outlet, and a second inlet; a first coolant outlet pipe is connected to the first inlet of the water-cooled heat exchanger, and the first outlet of the water-cooled heat exchanger is connected to the first coolant return pipe. The third cooling circulation pipeline includes a third coolant outlet pipe and a third coolant return pipe; a first electronic three-way valve is connected to the second inlet of the water-cooled heat exchanger through the third coolant outlet pipe, and the second outlet of the water-cooled heat exchanger is connected to the second electronic three-way valve through the third coolant return pipe.

[0031] In a specific implementation, the battery water-cooling unit is selected based on the cooling demand under the maximum continuous current of battery charging. During normal operation of the whole machine, the discharge current is much smaller than the maximum continuous current, so the battery cooling demand is less than the rated demand. The cooling capacity of the water-cooling unit can be used to further cool the motor and electronic control system.

[0032] In a specific implementation, the battery thermal management system also includes a battery pack, and a second cooling circulation pipeline exchanges heat with the battery pack to cool the battery pack.

[0033] In a specific implementation, a water pump is installed on the first coolant outlet pipe of the radiator. The water pump is used to provide power to the coolant in the pipe and promote the circulation of the coolant.

[0034] In specific implementation methods, such as Figure 3 As shown, a water-to-water plate heat exchanger, also known as a water-to-water plate heat exchanger, consists of a series of metal plates with a certain corrugated shape. The plates are pressed together by sealing gaskets to form narrow rectangular channels. Figure 2As shown, the plates have holes at their four corners, which are designated as the first outlet, first inlet, second outlet, and second inlet, respectively. After assembly, these form a distribution pipe and a collection pipe for the coolant, allowing the coolant to enter and exit the metal plate channels. The heat transfer process in the water-to-water plate heat exchanger is as follows: the high-temperature coolant and the low-temperature coolant enter the adjacent plate channels through the corner holes, typically flowing in a counter-current or co-current manner. Since the high-temperature coolant is hotter than the low-temperature coolant, according to the laws of thermodynamics, heat is transferred from the high-temperature coolant to the low-temperature coolant through the plates, causing the temperature of the low-temperature coolant to rise and the temperature of the high-temperature coolant to fall. It should be noted that the above-described water-to-water plate heat exchanger is an existing structure, and no structural modifications have been made to the water-to-water plate heat exchanger in this embodiment.

[0035] In a specific implementation, two temperature sensors, designated as a first temperature sensor and a second temperature sensor, are installed on the first coolant outlet pipe. These sensors are positioned on opposite sides of the water-cooling heat exchanger. The first temperature sensor detects the temperature of the coolant before it enters the heat exchanger, acquiring first temperature data. The second temperature sensor monitors the temperature of the coolant after it passes through the heat exchanger, acquiring second temperature data. Both temperature sensors communicate with the controller, transmitting the two sets of temperature data. The controller compares these two sets of temperature data with preset temperature thresholds. If the first temperature data is higher than the first preset temperature threshold (60°C), the controller outputs a control signal to the first and second electronic three-way valves, opening them to introduce coolant from the cooling unit into the heat exchanger for heat exchange with the radiator's first coolant outlet pipe. Simultaneously, the controller acquires the second temperature data in real time. If the second temperature data is greater than the second preset temperature threshold (55℃), the controller outputs a control signal to increase the opening of the first and second electronic three-way valves, accelerating the flow rate of the coolant in the cooling unit introduced into the water heat exchanger and enhancing the cooling effect. If the second temperature data is less than the second preset temperature threshold (55℃), the first and second electronic three-way valves maintain their current opening. When the first temperature data is lower than the first preset temperature threshold (55℃), the controller outputs a control signal to the first and second electronic three-way valves to close them, allowing independent cooling for the battery pack, motor, and motor controller. Specifically, a lower second temperature data than the preset temperature may be due to a decrease in coolant temperature after heat exchange. The first temperature data should be compared with the second preset temperature, i.e., the actual temperature before entering the heat exchanger should be compared with the required coolant temperature after heat exchange. For example, if the first temperature data is 50℃ and the second preset temperature threshold is 55℃, the valves should be closed; if the first temperature data is 60℃ and the second temperature data is 54℃, the electronic three-way valves should remain open.

[0036] Working principle of this utility model: Under normal temperature conditions, when the radiator can meet the cooling needs of the motor and motor controller, the electronic three-way valve is closed, and the cooling of the motor and motor controller is independent of the battery pack cooling. Under high temperature conditions (ambient temperature ≥ 55℃), the radiator exceeds its own cooling limit and cannot meet the cooling needs of the motor and motor controller. At this time, the controller receives a first temperature data exceeding the set temperature threshold and outputs a control signal to the electronic three-way valve. The electronic three-way valve opens, introducing the water-cooled unit into the water-to-water heat exchanger to participate in the cooling cycle of the motor and motor controller. This allows the low-temperature coolant in the battery thermal management system to exchange heat with the high-temperature coolant in the radiator through the water-to-water heat exchanger, reducing the water temperature in the radiator circuit to meet the inlet water temperature requirements of the motor controller. The controller controls the opening and closing of the electronic three-way valve and its opening degree based on real-time temperature feedback from the temperature sensors. When the first temperature sensor detects a temperature ≥ 55℃, the corresponding electronic three-way valve opens; simultaneously, the second temperature sensor detects whether the water temperature in the radiator circuit after passing through the water-to-water heat exchanger is ≤ 55℃. The temperature difference between the two temperature sensors controls the cooling power demand of the water-cooled unit and the opening degree of the electronic three-way valve.

[0037] Example 2 This embodiment provides an electric excavator that uses a heat dissipation system for electric excavators as provided in Embodiment 1 for heat dissipation.

[0038] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. 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 solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A cooling system for an electric excavator, characterized in that, include: Radiators, battery thermal management systems, and water-cooled heat exchangers; The outlet and inlet of the radiator are connected to the first cooling circulation pipeline; The battery thermal management system includes a water-cooled unit with second coolant circulation pipelines connected to both sides of the water-cooled unit, and electronic three-way valves are respectively installed on the second coolant circulation pipelines on both sides of the water-cooled unit. The two electronic three-way valves are connected via a third cooling circulation pipe; The third cooling circulation pipeline and the first cooling circulation pipeline are connected by a water-to-water heat exchanger; The first cooling circulation pipeline exchanges heat with the motor and motor controller.

2. The cooling system for an electric excavator as described in claim 1, characterized in that, The first cooling circulation pipeline includes a first coolant outlet pipe and a first coolant return pipe; The outlet of the radiator is connected to the first coolant outlet pipe, and the inlet of the radiator is connected to the first coolant return pipe.

3. The cooling system for an electric excavator as described in claim 2, characterized in that, A water pump is installed on the first coolant outlet pipe.

4. The cooling system for an electric excavator as described in claim 1, characterized in that, The battery thermal management system also includes a battery pack, and a second cooling circulation pipeline exchanges heat with the battery pack.

5. A cooling system for an electric excavator as described in claim 2, characterized in that, The water-cooling plate heat exchanger includes a first outlet, a first inlet, a second outlet, and a second inlet; the first coolant outlet pipe is connected to the first inlet of the water-cooling plate heat exchanger, and the first outlet of the water-cooling plate heat exchanger is connected to the first coolant return pipe.

6. A cooling system for an electric excavator as described in claim 5, characterized in that, The third cooling circulation pipeline includes a third coolant outlet pipe and a third coolant return pipe; The first electronic three-way valve is connected to the second inlet of the water pump via the third coolant outlet pipe, and the second outlet of the water pump is connected to the second electronic three-way valve via the third coolant return pipe.

7. A cooling system for an electric excavator as described in claim 6, characterized in that, A first temperature sensor is installed on the first coolant outlet pipe; the first temperature sensor is located on the first inlet side of the water exchanger. A second temperature sensor is installed on the first coolant outlet pipe; the second temperature sensor is located on the first outlet side of the water exchanger.

8. A cooling system for an electric excavator as described in claim 7, characterized in that, The first temperature sensor and the second temperature sensor communicate with the controller, respectively.

9. A cooling system for an electric excavator as described in claim 7, characterized in that, The first electronic three-way valve and the second electronic three-way valve communicate with the controller, respectively.

10. An electric excavator, characterized in that, The heat dissipation is achieved using a cooling system for electric excavators as described in any one of claims 1-9.

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