High-voltage lithium battery heat dissipation system of forklift and forklift

Abstract

A forklift high-voltage lithium battery heat dissipation system and forklift, comprising a plurality of lithium battery groups, each lithium battery group is provided with a heat dissipation pipeline, the heat dissipation pipelines of the plurality of lithium battery groups are sequentially connected to form a heat dissipation pipeline group, further comprising a refrigeration circulating device and a pump body, the refrigeration circulating device is provided with a heat exchanger, the input end of the pump body is connected with the output end of the heat dissipation pipeline group, the output end of the pump body is connected with the cooling liquid input end of the heat exchanger to drive the cooling liquid to circulate between the heat dissipation pipeline group and the heat exchanger, so that the lithium battery group is cooled, and the heat exchanger exchanges heat between the cooling liquid of the heat dissipation pipeline group and refrigerant, and the cooling liquid output end thereof is connected with the input end of the heat dissipation pipeline group.The utility model adopts the integrated design of the refrigeration circulating device and the lithium battery group heat dissipation pipeline, constructs a compact liquid cooling heat dissipation system, improves the cooling efficiency, and prolongs the service life of the lithium battery group.

Description

Technical Field

[0001] This utility model relates to the field of forklifts, and in particular to a high-voltage lithium battery cooling system for forklifts and a forklift. Background Technology

[0002] In the field of industrial vehicles such as forklifts, existing high-voltage lithium batteries mostly adopt natural cooling or forced air cooling solutions, which are difficult to meet the heat dissipation requirements under high-intensity operation. Natural cooling relies on passive heat exchange with ambient air. Under continuous heavy load or high-temperature conditions, heat accumulation inside the battery can easily lead to uncontrolled temperature rise of the cell. Although air cooling systems improve heat dissipation capacity through forced airflow, the air duct layout is difficult to optimize due to the closed frame structure of forklifts. Significant temperature differences inside the battery module directly affect the cycle life and output stability of the battery pack.

[0003] The compact space of the forklift battery compartment further highlights the limitations of traditional cooling solutions. Air-cooled systems require large-volume airflow chambers and external filters, further encroaching on already limited layout space. Moreover, the dusty and high-vibration environment of forklift operations easily leads to filter clogging and airflow structure deformation, resulting in increased maintenance costs. Furthermore, existing cooling components lack integrated design with the forklift frame; each component requires additional reinforcement brackets during installation, increasing manufacturing costs and reducing the overall impact resistance of the system. Utility Model Content

[0004] The main purpose of this invention is to overcome existing defects and propose a high-voltage lithium battery cooling system for forklifts and a forklift in general. By integrating the refrigeration cycle device with the lithium battery pack cooling pipes, a compact liquid cooling system is constructed to improve cooling efficiency and extend the life of the lithium battery pack.

[0005] The present invention adopts the following technical solution:

[0006] A high-voltage lithium battery cooling system for a forklift includes several lithium battery packs, each with a cooling pipe; the cooling pipes of the several lithium battery packs are connected in series to form a cooling pipe group; it also includes a refrigeration circulation device and a pump body, the refrigeration circulation device being equipped with a heat exchanger, the pump body's input end being connected to the output end of the cooling pipe group, and the pump body's output end being connected to the coolant input end of the heat exchanger to drive the coolant to circulate between the cooling pipe group and the heat exchanger to achieve heat dissipation of the lithium battery packs; the heat exchanger exchanges heat between the coolant and refrigerant in the cooling pipe group, and its coolant output end is connected to the input end of the cooling pipe group.

[0007] Furthermore, the refrigeration cycle device also includes a compressor, a condenser, and a controller; the exhaust port of the compressor is connected to the refrigerant inlet of the condenser, for delivering the compressed high-temperature gaseous refrigerant to the condenser; the refrigerant outlet of the condenser is connected to the refrigerant inlet of the heat exchanger, for introducing the liquefied refrigerant into the heat exchanger after throttling to exchange heat with the coolant of the heat dissipation pipe assembly; the refrigerant outlet of the heat exchanger is connected to the suction port of the compressor to form a closed-loop refrigerant circulation circuit; the controller is connected to the compressor, the condenser, the heat exchanger, and the pump body.

[0008] Furthermore, the refrigerant used in the refrigeration cycle device is R134a refrigerant, and the coolant is an aqueous solution of ethylene glycol.

[0009] Furthermore, it also includes a frame with a mounting cavity; the refrigeration cycle device and the pump body are installed in the mounting cavity; and a plurality of the lithium battery packs are located on one side of the frame.

[0010] Furthermore, it also includes a bracket on which several of the lithium battery packs are mounted, the bracket being located on one side of the frame.

[0011] Furthermore, the system also includes an expansion tank and a connecting pipe, one end of which is connected to the expansion tank and the other end of which is connected to the coolant inlet or outlet of the heat dissipation pipe assembly.

[0012] Furthermore, the lithium battery packs are arranged vertically, with the heat dissipation pipe of each lithium battery pack located at the bottom of the lithium battery pack; in the vertical direction, the expansion tank is arranged such that its height is higher than the heat dissipation pipe of the topmost lithium battery pack.

[0013] Furthermore, it also includes a three-way valve body, which is installed between the connecting pipe and the heat dissipation pipe assembly.

[0014] A forklift includes a forklift body, the forklift body being provided with a battery compartment, and the battery compartment being provided with a high-voltage lithium battery cooling system for the forklift.

[0015] It also includes a bracket, which is slidably fitted with the battery compartment, and several of the lithium battery packs, the refrigeration cycle device and the pump body are fixed on the bracket.

[0016] As can be seen from the above description of this utility model, compared with the prior art, this utility model has the following beneficial effects:

[0017] 1. In this utility model, a refrigeration circulation device and a pump body are provided. The pump body is connected between the heat dissipation pipe assembly and the heat exchanger of the refrigeration circulation device to drive the coolant to circulate between the heat dissipation pipe assembly and the heat exchanger. The heat exchanger exchanges heat between the coolant of the heat dissipation pipe assembly and the refrigerant to achieve heat dissipation. By adopting this integrated design of the refrigeration circulation device and the lithium battery pack heat dissipation pipe, a compact liquid cooling heat dissipation system is constructed, which improves cooling efficiency and extends the life of the lithium battery pack.

[0018] 2. In this utility model, a frame is set up to install the refrigeration circulation device and the pump body, and the frame is set on one side of the lithium battery pack. The frame is set close to the lithium battery pack, which makes the circulation path of the coolant short. The low temperature coolant flowing out of the refrigeration circulation device can flow into the lithium battery pack more quickly to remove heat and dissipate heat faster.

[0019] 3. This utility model also includes a bracket and a support frame. Several lithium battery packs are installed on the bracket, and the bracket and the frame are fixed on the support frame. The cooling cycle device can be pulled out or put in along with the lithium battery packs as a whole, which is convenient for installation and maintenance. The compact layout reduces the redundant space occupied inside the equipment, while ensuring that the lithium battery packs and the cooling cycle device are positioned close to each other to maintain the high efficiency of the heat dissipation path.

[0020] 4. In this utility model, an expansion tank is also provided connected to the heat dissipation pipe assembly. In the vertical direction, the expansion tank is configured such that its height is higher than the heat dissipation pipe of the top lithium battery pack. This can absorb the volume changes caused by the expansion or contraction of the coolant, avoid excessive system pressure, and protect the sealing of the pipes and connectors. When the coolant decreases due to evaporation or leakage, the expansion tank, as a liquid storage container, can also replenish the coolant and maintain a stable circulation flow. A three-way valve can also be provided at the connection between the expansion tank and the heat dissipation pipe assembly. When the pressure of the heat dissipation system increases suddenly due to battery expansion or high temperature, the pressure can be released by switching the channel of the three-way valve, releasing the excess pressure to the expansion tank to protect the heat dissipation pipe assembly. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the present utility model;

[0022] Figure 2 This is a perspective view of the present utility model;

[0023] Figure 3 for Figure 1 Top view;

[0024] Figure 4 This is a structural diagram of the circulating cooling device and the frame;

[0025] Figure 5 A three-dimensional view of the circulating cooling system and the frame;

[0026] Figure 6This is a partial structural diagram of the present utility model;

[0027] Figure 7 A schematic diagram showing the flow direction of the coolant in the cooling pipe assembly;

[0028] Figure 8 This is a structural diagram of the present utility model (including bracket and support).

[0029] Figure 9 for Figure 8 Side view;

[0030] in:

[0031] 10. Lithium battery pack; 11. Input port; 12. Output port; 13. Heat dissipation pipe assembly; 14. Input end; 15. Output end; 16. Expansion tank; 17. Connecting pipe; 18. Connecting plate; 19. Three-way valve body; 20. Refrigeration cycle device; 21. Heat exchanger; 22. Compressor; 23. Condenser; 24. Controller; 25. Coolant input end; 26. Coolant output end; 27. DC transformer; 30. Pump body; 40. Frame; 41. Mounting cavity; 50. Bracket; 60. Bracket. Detailed Implementation

[0032] The present invention will be further described below through specific embodiments.

[0033] See Figures 1 to 7 A high-voltage lithium battery cooling system for a forklift includes several lithium battery packs 10, a cooling circulation device 20, and a pump body 30. Each lithium battery pack 10 has a cooling pipe with a conventional cooling structure (not shown in the figure), such as a serpentine or grid-like layout, which closely adheres to the surface of the battery cells to form a uniform thermally conductive contact surface. These pipes actively absorb the heat generated by the charging and discharging of the battery through circulating coolant. Each lithium battery pack 10's cooling pipe has an inlet 11 and an outlet 12. The cooling pipes of several lithium battery packs 10 are connected in series to form a cooling pipe group 13, through which coolant can flow sequentially.

[0034] The refrigeration cycle device 20 includes a heat exchanger 21, a compressor 22, a condenser 23, and a controller 24. The heat exchanger 21 is one of the core components of the refrigeration cycle device 20. Coolant and refrigerant lines are distributed in parallel within it, and heat exchange between the two fluids is achieved through a metal heat-conducting wall. The low-temperature liquid refrigerant absorbs the heat released by the coolant, carrying away the heat energy of the coolant in the coolant lines, thereby reducing the coolant temperature. Specifically, the input end of the pump body 30 is connected to the output end 15 of the heat dissipation pipe assembly 13, the output end of the pump body 30 is connected to the coolant input end 25 of the heat exchanger 21, and the coolant output end 26 of the heat exchanger 21 is connected to the input end 14 of the heat dissipation pipe assembly 13. The pump drives the coolant to circulate between the heat dissipation pipe assembly 13 and the heat exchanger 21 to realize the heat exchange between the coolant and refrigerant in the heat dissipation pipe assembly 13 for the lithium battery pack 10. In practical applications, the refrigerant used in the refrigeration cycle device 20 is R134a, and the coolant is an aqueous solution of ethylene glycol.

[0035] The exhaust port of compressor 22 is connected to the refrigerant inlet of condenser 23, used to deliver the compressed high-temperature gaseous refrigerant to condenser 23. Condenser 23 is configured to dissipate heat from the refrigerant through external air cooling (e.g., a fan) or liquid cooling, causing it to change from a gaseous to a liquid state. In the various figures, only the fan is shown in the condenser 23; the complete structural diagram is not presented. Other specific structures of condenser 23 can be implemented using existing condenser structures. The refrigerant outlet of condenser 23 is connected to the refrigerant inlet of heat exchanger 21, used to introduce the liquefied refrigerant into heat exchanger 21 after throttling for heat exchange with the coolant in the heat dissipation pipe assembly 13. The refrigerant outlet of heat exchanger 21 is connected to the suction port of compressor 22, forming a closed-loop refrigerant circulation circuit.

[0036] The controller 24 is connected to the compressor 22, condenser 23, heat exchanger 21, and pump 30. It enables coordinated operation of multiple devices by regulating the compressor 22, coordinating the heat dissipation of the condenser 23, adjusting the flow rates of the heat exchanger 21 and pump 30, and controlling refrigerant throttling. The controller 24 can be an LDCM1922D. The compressor 22, condenser 23, and heat exchanger 21 in the figures of this utility model are simplified diagrams and do not show their complete structures; their specific structures can be implemented using existing designs.

[0037] Furthermore, it also includes a frame 40, which adopts a metal shell structure and has an installation cavity 41 inside. The refrigeration circulation device 20 and the pump body 30 are installed in the installation cavity 41. The positions of the compressor 22, condenser 23, heat exchanger 21, controller 24 and pump body 30 in the installation cavity 41 can be set according to actual needs. The expansion tank 16 is located above the frame 40 and is fixed to the frame 40 relative to it by a connecting plate 18. Several lithium battery packs 10 are located on one side of the frame 40, that is, the frame 40 is set close to the lithium battery packs 10, which makes the circulation path of the coolant shorter. The low temperature coolant flowing out of the refrigeration circulation device 20 can flow into the lithium battery packs 10 more quickly to remove heat, resulting in faster heat dissipation and less energy loss.

[0038] In this embodiment, see Figure 8 and Figure 9 It also includes a bracket 50, which is fixedly positioned relative to the frame 40. Several lithium battery packs 10 are mounted on the bracket 50 and arranged vertically. The cooling circulation device 20 can be pulled out or put in along with the lithium battery packs 10 for easy installation and maintenance. The compact layout reduces redundant space inside the equipment while ensuring that the lithium battery packs 10 and the cooling circulation device 20 are positioned close to each other to maintain the high efficiency of the heat dissipation path.

[0039] Furthermore, it also includes an expansion tank 16 and a connecting pipe 17. One end of the connecting pipe 17 is connected to the expansion tank, and the other end is connected to the coolant inlet 25 or coolant outlet 26 of the heat dissipation pipe assembly 13. In the figure, the connecting pipe 17 is connected to the coolant outlet 26 of the heat dissipation pipe assembly 13. During the circulation process, the coolant volume fluctuates due to temperature changes. The expansion tank 16, connected to the heat dissipation pipe assembly 13 through the connecting pipe 17, can absorb the volume changes caused by the expansion or contraction of the coolant, preventing excessive system pressure or the formation of a vacuum, and protecting the sealing of the pipes and connections. When the coolant decreases due to evaporation or leakage, the expansion tank 16, as a liquid storage container, can also replenish the coolant to maintain a stable circulation flow rate.

[0040] In the lithium battery pack 10, the heat dissipation pipes of each lithium battery pack 10 are located at the bottom of the lithium battery pack 10. Vertically, the expansion tank 16 is positioned higher than the heat dissipation pipes of the top lithium battery pack 10. The height of the expansion tank 16 can be 100mm-500mm higher than the heat dissipation pipes of the top lithium battery pack 10, for example, 199mm. This design, with the expansion tank 16 higher than the heat dissipation pipe assembly 13, allows for natural coolant recirculation using gravitational potential energy. When the coolant expands due to heat, excess liquid automatically flows into the expansion tank 16 through the connecting pipe 17; when the coolant temperature drops and it contracts, the coolant in the expansion tank 16 can flow back to replenish the heat dissipation pipe assembly 13, preventing abnormal pressure or partial vacuum in the heat dissipation pipe assembly 13 due to volume fluctuations and ensuring reliable pipe sealing.

[0041] Furthermore, as needed, the system is also equipped with a three-way valve body 19, which is installed between the connecting pipe 17 and the heat dissipation pipe assembly 13. Specifically, the three-way valve body 19 is connected between the output end 15 of the heat dissipation pipe assembly 13 and the connecting pipe 17. When the heat dissipation system experiences a sudden increase in pressure due to air or battery expansion at high temperatures, the three-way valve body 19 can be switched to connect the output end of the heat dissipation pipe assembly 13 to the expansion tank 16 for venting and pressure relief. This releases the air or excess pressure in the pipes to the expansion tank 16, ensuring that the coolant fills the heat dissipation pipe assembly 13 and protects it.

[0042] Based on this, the present invention also proposes a forklift, including a forklift body, a battery compartment, and a high-voltage lithium battery cooling system as described above. Several lithium battery packs 10 provide power to the forklift body. The cooling system also includes a DC transformer 27, which converts the voltage output from the lithium battery packs 10 to power components such as the cooling cycle device 20 and the pump body 30. A bracket 60 is also provided, which engages with the battery compartment via a slide rail or guide groove. The support 50 and the frame 60 are fixed to the bracket 60, thus enabling the overall horizontal movement of the cooling system (including the lithium battery packs 10 and the cooling cycle device 20).

[0043] This invention utilizes a sliding fit design between the bracket 60 and the battery compartment, allowing the bracket 60 to be directly pulled out of the battery compartment along a slide rail. This facilitates the overall maintenance or replacement of the lithium battery pack 10 and the cooling system, reducing equipment downtime. The forklift using this cooling system not only achieves excellent heat dissipation efficiency but also, through a circulating refrigeration device, removes waste heat from the battery compartment or the forklift itself, effectively solving the negative impact of high ambient temperatures caused by waste heat being discharged from the battery compartment.

[0044] The terms "first" and "second" used in this utility model are merely for ease of description and to distinguish different components with the same name, and do not indicate a sequential or primary / secondary relationship.

[0045] In the description of this utility model, the orientation or positional relationship indicated by terms such as "up", "down", "left", "right", "front" and "back" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing this utility model and is not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this utility model.

[0046] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0047] The above are merely specific embodiments of this utility model, but the design concept of this utility model is not limited thereto. Any non-substantial modifications made to this utility model using this concept shall be considered as an infringement of the protection scope of this utility model.

Claims

1. A high-voltage lithium battery cooling system for a forklift, comprising a plurality of lithium battery packs, each lithium battery pack having a cooling pipe; characterized in that: A plurality of the heat dissipation pipes of the lithium battery pack are connected in series to form a heat dissipation pipe group; it also includes a refrigeration cycle device and a pump body. The refrigeration cycle device is equipped with a heat exchanger. The input end of the pump body is connected to the output end of the heat dissipation pipe group, and the output end of the pump body is connected to the coolant input end of the heat exchanger to drive the coolant to circulate between the heat dissipation pipe group and the heat exchanger to achieve heat dissipation of the lithium battery pack; the heat exchanger exchanges heat between the coolant and the refrigerant of the heat dissipation pipe group, and its coolant output end is connected to the input end of the heat dissipation pipe group.

2. The high-voltage lithium battery cooling system for a forklift as described in claim 1, characterized in that: The refrigeration cycle device further includes a compressor, a condenser, and a controller; the exhaust port of the compressor is connected to the refrigerant inlet of the condenser, for delivering the compressed high-temperature gaseous refrigerant to the condenser; the refrigerant outlet of the condenser is connected to the refrigerant inlet of the heat exchanger, for introducing the liquefied refrigerant into the heat exchanger after throttling to exchange heat with the coolant of the heat dissipation pipe assembly. The refrigerant outlet of the heat exchanger is connected to the suction port of the compressor to form a closed-loop refrigerant circulation circuit; the controller is connected to the compressor, the condenser, the heat exchanger and the pump body.

3. The high-voltage lithium battery cooling system for a forklift as described in claim 2, characterized in that: The refrigerant used in the refrigeration cycle device is R134a refrigerant, and the coolant is an aqueous solution of ethylene glycol.

4. The high-voltage lithium battery cooling system for a forklift as described in claim 1, characterized in that: It also includes a frame with a mounting cavity; the refrigeration cycle device and the pump body are installed in the mounting cavity; and a plurality of lithium battery packs are located on one side of the frame.

5. The high-voltage lithium battery cooling system for a forklift as described in claim 4, characterized in that: It also includes a bracket on which several of the lithium battery packs are mounted, the bracket being located on one side of the frame.

6. The high-voltage lithium battery cooling system for a forklift as described in claim 1, characterized in that: It also includes an expansion tank and a connecting pipe, one end of which is connected to the expansion tank and the other end is connected to the coolant inlet or outlet of the heat dissipation pipe assembly.

7. The high-voltage lithium battery cooling system for a forklift as described in claim 6, characterized in that: The lithium battery packs are arranged vertically, with the heat dissipation pipe of each lithium battery pack located at the bottom of the lithium battery pack; in the vertical direction, the expansion tank is arranged such that its height is higher than the heat dissipation pipe of the top lithium battery pack.

8. The high-voltage lithium battery cooling system for a forklift as described in claim 6, characterized in that: It also includes a three-way valve body, which is installed between the connecting pipe and the heat dissipation pipe assembly.

9. A forklift, comprising a forklift body, wherein the forklift body is provided with a battery compartment, characterized in that: The battery compartment is provided with a high-voltage lithium battery cooling system for a forklift according to any one of claims 1 to 8.

10. A forklift as described in claim 9, characterized in that: It also includes a bracket, which is slidably fitted with the battery compartment, and several of the lithium battery packs, the refrigeration cycle device and the pump body are fixed on the bracket.

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