Layered cold-supplemented liquid-cooled battery cluster and temperature control method thereof

Abstract

This invention discloses a layered cooling liquid-cooled battery cluster and its temperature control method, relating to the field of electrochemical energy storage battery thermal management technology. The key technical points are: multiple battery packs stacked vertically, each battery pack including an open-top housing, cell modules, and a cooling unit; the bottom of the open-top housing has flow equalization holes, and the cooling unit is connected to an external cold source; a liquid distribution device, located above the top open-top housing, for evenly distributing coolant into the top open-top housing, the flow equalization holes being configured to maintain a preset working liquid level in the open-top housing; a liquid collection container, located below the bottom open-top housing, for collecting coolant flowing out from the flow equalization holes of the bottom open-top housing; and a coolant circulation pipeline connecting the liquid collection container and the liquid distribution device, with a delivery pump installed on the coolant circulation pipeline. This invention has the advantages of low coolant consumption, good temperature uniformity across the entire battery cluster, and low manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for electrochemical energy storage batteries, and more specifically, to a layered cooling liquid-cooled battery cluster and its temperature control method. Background Technology

[0002] Electrochemical energy storage systems are widely used in power peak shaving and renewable energy grid connection. As the core unit of the energy storage system, the thermal management performance of the battery cluster directly affects the cell efficiency, cycle life, and system safety. Liquid cooling is widely used in battery cluster thermal management due to its high heat exchange efficiency and good temperature uniformity.

[0003] Traditional battery cluster immersion thermal management requires sealing the entire battery cluster and filling it with immersion fluid, immersing all cells in the fluid for heat exchange. This approach consumes a large amount of immersion fluid, resulting in a heavier system, increased costs, and difficulty in flexibly controlling the fluid level. Furthermore, due to the centralized cooling mode, heat accumulates layer by layer as the immersion fluid flows downwards, causing significant temperature differences between the upper and lower layers of the battery cluster. This affects the temperature uniformity of the cells, reducing cell lifespan and increasing the risk of thermal runaway. In addition, to accommodate the large amount of immersion fluid and prevent leakage, the protective casing of the battery cluster must meet high sealing performance and pressure resistance requirements, leading to complex structural design, increased manufacturing costs, and the risk of aging and failure of seals during long-term operation, posing a safety hazard of immersion fluid leakage.

[0004] Therefore, a new solution is needed to address the above problems. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a layered cooling liquid-cooled battery cluster and its temperature control method, which has the advantages of low coolant consumption, good temperature consistency of the entire cluster of battery cells, and low manufacturing cost.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a layered cooling liquid-cooled battery cluster, comprising:

[0007] Multiple battery packs are stacked vertically. Each battery pack includes an open housing, a cell module disposed in the open housing, and a cooling unit. A flow equalization hole is provided through the bottom of the open housing, and the cooling unit is connected to an external cold source.

[0008] A liquid distribution device is installed above the topmost open-top tank to evenly distribute coolant into the topmost open-top tank. After being distributed by the liquid distribution device, the coolant flows from the topmost open-top tank to the bottommost open-top tank under the action of gravity. The flow equalization hole is configured to maintain the coolant in the open-top tank at a preset working level.

[0009] A liquid collection container is disposed below the bottommost open-top tank to collect the coolant flowing out of the equalization holes of the bottommost open-top tank.

[0010] A coolant circulation pipeline connects the liquid accumulation container and the liquid distribution device, and a delivery pump is installed on the coolant circulation pipeline.

[0011] Preferably, the cooling replenishment unit is located at the bottom of the uncovered enclosure and is configured to be completely submerged below the preset working liquid level during operation.

[0012] Preferably, the cooling unit is a heat exchange tube disposed in the uncovered box, with both ends of the heat exchange tube extending to the side wall of the uncovered box, and a cold source inlet and a cold source outlet correspondingly formed on the side wall of the uncovered box. The cold source inlet is used to connect to the output end of an external cold source, and the cold source outlet is used to connect to the input end of an external cold source.

[0013] Preferably, the heat exchange tube is bent in a serpentine shape to form a covered heat dissipation surface at the bottom of the uncovered housing.

[0014] Preferably, the liquid distribution device includes a liquid distribution plate, a liquid distribution cavity is provided in the liquid distribution plate, and a plurality of liquid distribution holes are evenly distributed on the liquid distribution plate. The liquid distribution holes communicate with the liquid distribution cavity, and the liquid distribution cavity communicates with the coolant circulation pipeline.

[0015] Preferably, the battery cell module includes multiple battery cells, each battery cell includes two terminals, and the liquid distribution hole and the flow equalization hole are arranged one-to-one with the terminals of the multiple battery cells in terms of number and position.

[0016] Preferably, a module bracket is fixed to the bottom of the uncovered housing, the battery cell module is mounted on the module bracket, and the cooling unit is located below the module bracket.

[0017] Preferably, the diameter of both the liquid distribution hole and the flow equalization hole is 1mm-2mm.

[0018] Preferably, it also includes a cabinet, in which the liquid distribution device, the plurality of battery packs, the liquid accumulation container, the coolant circulation pipeline and the delivery pump are all disposed.

[0019] A temperature control method for a layered cooling liquid-cooled battery cluster, applied to any of the layered cooling liquid-cooled battery clusters described above, includes the following steps:

[0020] The delivery pump delivers the coolant from the liquid accumulation container to the liquid distribution device through the coolant circulation pipeline. The liquid distribution device then evenly distributes the coolant into the topmost uncovered tank. After being distributed by the liquid distribution device, the coolant flows from the topmost uncovered tank to the bottommost uncovered tank under the action of gravity, and the flow equalization holes maintain a preset working liquid level in each uncovered tank.

[0021] After flowing through the bottommost open tank, the coolant flows into the liquid collection container and is then pumped again to the liquid distribution device, forming a closed loop.

[0022] The preset working liquid level and coolant flow rate in each of the uncovered tanks can be adjusted by controlling the rotation speed of the delivery pump to adapt to the heat dissipation requirements under different working conditions. When the delivery pump is stopped, the coolant in each of the uncovered tanks flows back to the liquid accumulation container under the action of gravity, and each of the uncovered tanks is in a state of no liquid level.

[0023] Compared with existing technologies, the advantages of the layered cooling liquid-cooled battery cluster and its temperature control method disclosed in this invention are:

[0024] 1. By setting up a liquid distribution device, the coolant is evenly distributed to the top coverless tank, and a flow equalization hole is set through the bottom of each coverless tank, so that the coolant flows from top to bottom layer by layer under the action of gravity. The coverless tank only needs to maintain the preset working liquid level instead of being fully immersed, which reduces the amount of coolant used, reduces the weight and cost of the battery cluster, and makes the liquid level control more flexible.

[0025] 2. By setting up a cooling unit in each uncovered enclosure and connecting the cooling unit to an external cold source, the coolant in the uncovered enclosure can be cooled on-site, effectively suppressing the heat accumulation of the coolant during the layer-by-layer flow process, effectively reducing the temperature difference between the top and bottom uncovered enclosures, improving the temperature consistency of the entire cluster of battery cells, extending the service life of the battery cells, and reducing the risk of thermal runaway.

[0026] 3. By maintaining only the preset working liquid level in the uncovered tank instead of being fully submerged, the amount of coolant used is effectively reduced, thereby reducing the overall weight of the battery pack. At the same time, the requirements for the sealing performance and pressure resistance of the protective structure of the battery pack are greatly reduced, simplifying the structural design and reducing manufacturing costs. Furthermore, when the delivery pump is stopped, the coolant in each uncovered tank automatically flows back to the liquid collection container under the action of gravity, leaving the uncovered tank in a state of no liquid level, thus reducing the safety hazard of coolant leakage.

[0027] 4. By controlling the speed of the delivery pump, the preset working liquid level and coolant flow rate in each uncovered tank can be flexibly adjusted to meet the heat dissipation requirements under different working conditions, thereby improving the adaptability and operational reliability of the battery cluster. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the layered cooling liquid-cooled battery cluster according to an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the battery pack structure according to an embodiment of this application;

[0031] Figure 3 This is a schematic diagram of the internal structure of the lidless box according to an embodiment of this application;

[0032] Figure 4 This is a schematic diagram of coolant flowing from top to bottom.

[0033] Figure 5 This is a schematic diagram of the liquid distribution device according to an embodiment of this application.

[0034] The numbers or letters in the attached diagram represent the names of the corresponding components:

[0035] 1. Cabinet; 2. Battery pack; 21. Open cabinet; 211. Flow equalization hole; 22. Battery cell module; 23. Heat exchange tube; 231. Cold source inlet; 232. Cold source outlet; 24. Module bracket; 25. Preset working liquid level; 3. Liquid distribution device; 31. Liquid distribution plate; 311. Liquid distribution hole; 312. Coolant inlet; 4. Coolant circulation pipeline; 5. Liquid collection container; 6. Transfer pump. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described through specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Please see also Figures 1 to 5This application provides a layered cooling liquid-cooled battery cluster, including a cabinet 1 and multiple battery packs 2, a liquid distribution device 3, a liquid collection container 5, a coolant circulation pipeline 4, and a delivery pump 6 disposed within the cabinet 1. The delivery pump 6 is disposed on the coolant circulation pipeline 4. The multiple battery packs 2 are stacked vertically, and each battery pack 2 includes an open housing 21, a cell module 22 disposed within the open housing 21, and a cooling unit. The open housing 21 adopts an open structure with a top opening, which eliminates the need for a top cover and sealing structure required by traditional battery packs 2 without significantly sacrificing the energy density of the battery cluster. The structure is more compact and provides a channel for direct flow of coolant. The bottom of the uncovered housing 21 is provided with a flow equalization hole 211. The diameter of the flow equalization hole 211 is 1mm-2mm, specifically 1mm, 1.5mm, or 2mm. This diameter range ensures smooth flow of coolant while maintaining a stable preset working liquid level 25 within the uncovered housing 21 by utilizing the surface tension of the liquid and the orifice resistance, thus preventing excessive coolant loss. The size and arrangement of the flow equalization holes 211 in each layer of the uncovered housing 21 are uniform. When the coolant flows through each layer of flow equalization holes 211 under gravity, the self-balancing distribution of the coolant flow rate of the entire cluster can be achieved by relying on the static pressure of the liquid level. That is, the higher the liquid level, the greater the static pressure at the outlet of the flow equalization hole 211, and the flow rate automatically increases; the lower the liquid level, the automatically smaller the flow rate. This achieves adaptive matching between liquid level and flow rate, eliminating the need for additional flow regulating valves, resulting in a simple structure and reliable operation. By employing a structure with a coverless housing 21 and flow equalization holes 211, the coolant, after being distributed by the liquid distribution device 3, flows from the top of the top coverless housing 21 to the surface of the cell module 22. The bottom of the coverless housing 21 maintains a preset working liquid level 25 due to the throttling effect of the flow equalization holes 211, allowing the bottom of the cell module 22 to be partially immersed in the coolant, forming a composite heat dissipation mode of top-drip and bottom-immersion. Each coverless housing 21 only needs to maintain a preset working liquid level 25 instead of being fully immersed, significantly reducing the amount of coolant used, lowering the weight and cost of the battery cluster, and making liquid level control more flexible.

[0038] The coolant distribution device 3 is located above the top-level open-top housing 21. The device includes a distribution plate 31 with a distribution chamber within it. The distribution plate 31 has a plurality of evenly distributed distribution holes 311, which communicate with the distribution chamber. The distribution chamber is connected to the coolant circulation pipe 4. Specifically, the distribution plate 31 also has a coolant inlet 312 communicating with the distribution chamber, and the coolant circulation pipe 4 is connected to the coolant inlet 312. After entering the distribution chamber through the coolant circulation pipe 4, the coolant is evenly distributed into the top-level open-top housing 21 through the evenly distributed distribution holes 311, ensuring the uniformity of the coolant distribution during the initial distribution phase.

[0039] The battery module 22 comprises multiple individual battery cells, each containing two terminals, which are the areas where heat generation is most concentrated. The distribution holes 311 and flow equalization holes 211 are arranged one-to-one with the terminals of the multiple battery cells, meaning there is a distribution hole 311 or flow equalization hole 211 directly above each terminal. This allows the coolant to drip precisely from the distribution holes 311 or flow equalization holes 211 onto the terminals of the lower battery cells, prioritizing the cooling of the areas with the highest heat generation. Subsequently, under gravity, the coolant continues to flow downwards along the surface of the battery cells, evenly covering the surface of the battery module 22 for heat exchange, effectively improving heat exchange efficiency. During the downward flow of coolant, the bottom of the uncovered housing 21 maintains a preset working liquid level 25 due to the throttling effect of the flow equalization holes 211. The lower part of the battery module 22 is immersed in the coolant, while the upper part is evenly covered by the downward-flowing coolant. Compared to the traditional battery cluster immersion thermal management method, which has a large temperature difference between the upper and lower parts of the battery cluster, and the simple spray solution, which has insufficient heat exchange at the bottom of the individual cells, the combined top spray and bottom bubble heat dissipation mode of this embodiment makes the temperature distribution of the individual cells more uniform along their height direction, and the temperature uniformity of the individual cells is better.

[0040] The cooling unit is located at the bottom of the uncovered housing 21 and is connected to an external cold source. The external cold source provides cooling medium to the cooling unit and can be existing refrigeration equipment such as a water-cooled unit or a direct-cooling unit. A module support 24 is fixed to the bottom of the uncovered housing 21, and the battery cell module 22 is mounted on the module support 24. The cooling unit is located below the module support 24, so that the cooling unit is embedded in the space between the module support 24 and the bottom wall of the uncovered housing 21, resulting in a compact structure that does not occupy additional effective volume inside the uncovered housing 21. In operation, the cooling unit is completely submerged below the preset working liquid level 25, ensuring that the cooling unit is always in full contact with the coolant and maintaining high heat exchange efficiency.

[0041] The cooling unit specifically comprises heat exchange tubes 23 installed within the uncovered enclosure 21. Both ends of the heat exchange tubes 23 extend to the side walls of the uncovered enclosure 21, and corresponding cold source inlets 231 and cold source outlets 232 are formed on the side walls. The cold source inlet 231 connects to the output end of an external cold source, and the cold source outlet 232 connects to the input end of the external cold source. The cooling medium provided by the external cold source enters the heat exchange tubes 23 through the cold source inlet 231, absorbs heat from the coolant inside the uncovered enclosure 21, and then flows back to the external cold source from the cold source outlet 232, thereby cooling the coolant inside the uncovered enclosure 21 in situ. The heat exchange tubes 23 are bent in a serpentine shape to form a covering heat dissipation surface at the bottom of the uncovered enclosure 21, increasing the heat exchange area and further improving the cooling effect. By installing a cooling unit in each uncovered enclosure 21 for local cooling, the coolant is recooled to a lower temperature before entering the next uncovered enclosure 21. This effectively suppresses heat accumulation in the coolant during the layer-by-layer flow process, reduces the temperature difference between the top and bottom uncovered enclosures 21, improves the temperature consistency of the entire cluster of battery modules 22, extends the service life of the battery modules 22, and reduces the risk of thermal runaway. Simultaneously, since the cooling units in each uncovered enclosure 21 can independently provide local cooling, the total coolant consumption is further reduced. The system's heat dissipation capacity does not rely on a large coolant heat capacity reserve, reducing coolant procurement and maintenance costs.

[0042] The liquid collection container 5 is located below the bottom open-top tank 21 and is used to collect the coolant flowing out of the flow equalization hole 211 of the bottom open-top tank 21. The coolant circulation pipeline 4 connects the liquid collection container 5 and the liquid distribution device 3, and the delivery pump 6 provides power for the circulation of the coolant.

[0043] This invention also discloses a temperature control method for a layered cooling liquid-cooled battery cluster, applied to the aforementioned layered cooling liquid-cooled battery cluster, comprising the following steps:

[0044] The delivery pump 6 delivers the coolant in the liquid collection container 5 to the liquid distribution device 3 through the coolant circulation pipeline 4. The liquid distribution device 3 evenly distributes the coolant into the top open tank 21. After being distributed by the liquid distribution device 3, the coolant flows from the top open tank 21 to the bottom open tank 21 under the action of gravity, and the flow equalization hole 211 is used to maintain the preset working liquid level 25 in each open tank 21.

[0045] After flowing through the bottom coverless tank 21, the coolant flows into the liquid collection container 5 and is then transported again by the transfer pump 6 to the liquid distribution device 3, forming a closed loop.

[0046] The preset working liquid level 25 and the flow rate of coolant in each uncovered tank 21 can be adjusted by controlling the rotation speed of the delivery pump 6 to adapt to the heat dissipation requirements under different working conditions. When the delivery pump 6 is stopped, the coolant in each uncovered tank 21 flows back to the liquid accumulation container 5 under the action of gravity, and each uncovered tank 21 is in a state of no liquid level.

[0047] Through the above temperature control method, the coolant continuously circulates in the closed loop, and the preset working liquid level 25 is maintained in each uncovered tank 21. The battery cell module 22 is always in a composite heat dissipation state of top spraying and bottom immersion, which has high heat exchange efficiency and good temperature uniformity. The heat dissipation intensity can be flexibly adjusted by controlling the speed of the delivery pump 6, and it can be adapted to different heat-generating conditions without changing the system structure. After shutdown, the coolant automatically flows back to the liquid accumulation container 5, and no coolant remains in the uncovered tank 21, which reduces the risk of leakage and maintenance costs.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A layered cooling liquid-cooled battery cluster, characterized in that, include: Multiple battery packs are stacked vertically. Each battery pack includes an open housing, a cell module disposed in the open housing, and a cooling unit. A flow equalization hole is provided through the bottom of the open housing, and the cooling unit is connected to an external cold source. A liquid distribution device is installed above the topmost open-top tank to evenly distribute coolant into the topmost open-top tank. After being distributed by the liquid distribution device, the coolant flows from the topmost open-top tank to the bottommost open-top tank under the action of gravity. The flow equalization hole is configured to maintain the coolant in the open-top tank at a preset working level. A liquid collection container is disposed below the bottommost open-top tank to collect the coolant flowing out of the equalization holes of the bottommost open-top tank. A coolant circulation pipeline connects the liquid accumulation container and the liquid distribution device, and a delivery pump is installed on the coolant circulation pipeline.

2. The layered cooling liquid-cooled battery cluster according to claim 1, characterized in that: The cooling replenishment unit is located at the bottom of the uncovered enclosure and is configured to be completely submerged below the preset working liquid level during operation.

3. The layered cooling liquid-cooled battery cluster according to claim 2, characterized in that: The cooling unit is a heat exchange tube installed inside the uncovered box. Both ends of the heat exchange tube extend to the side wall of the uncovered box, and a cold source inlet and a cold source outlet are formed on the side wall of the uncovered box. The cold source inlet is used to connect to the output end of an external cold source, and the cold source outlet is used to connect to the input end of an external cold source.

4. The layered cooling liquid-cooled battery cluster according to claim 3, characterized in that: The heat exchange tubes are bent in a serpentine shape to form a covered heat dissipation surface at the bottom of the uncovered enclosure.

5. The layered cooling liquid-cooled battery cluster according to claim 1, characterized in that: The liquid distribution device includes a liquid distribution plate, a liquid distribution cavity is provided in the liquid distribution plate, and a plurality of liquid distribution holes are evenly distributed on the liquid distribution plate. The liquid distribution holes are connected to the liquid distribution cavity, and the liquid distribution cavity is connected to the coolant circulation pipeline.

6. The layered cooling liquid-cooled battery cluster according to claim 5, characterized in that: The battery cell module includes multiple battery cells, each battery cell includes two terminals, and the liquid distribution hole and the flow equalization hole are arranged one-to-one with the terminals of the multiple battery cells in terms of number and position.

7. The layered cooling liquid-cooled battery cluster according to claim 1, characterized in that: The bottom of the uncovered enclosure is fixed with a module bracket, the battery cell module is mounted on the module bracket, and the cooling unit is located below the module bracket.

8. The layered cooling liquid-cooled battery cluster according to claim 6, characterized in that: The diameters of the liquid distribution holes and the flow equalization holes are both 1mm-2mm.

9. The layered cooling liquid-cooled battery cluster according to claim 1, characterized in that: It also includes a cabinet, and the liquid distribution device, multiple battery packs, liquid accumulation container, coolant circulation pipeline and delivery pump are all installed in the cabinet.

10. A temperature control method for a layered cooling liquid-cooled battery cluster, applied to the layered cooling liquid-cooled battery cluster as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The delivery pump delivers the coolant from the liquid accumulation container to the liquid distribution device through the coolant circulation pipeline. The liquid distribution device then evenly distributes the coolant into the topmost uncovered tank. After being distributed by the liquid distribution device, the coolant flows from the topmost uncovered tank to the bottommost uncovered tank under the action of gravity, and the flow equalization holes maintain a preset working liquid level in each uncovered tank. After flowing through the bottommost open tank, the coolant flows into the liquid collection container and is then pumped again to the liquid distribution device, forming a closed loop. The preset working liquid level and coolant flow rate in each of the uncovered tanks can be adjusted by controlling the rotation speed of the delivery pump to adapt to the heat dissipation requirements under different working conditions. When the delivery pump is stopped, the coolant in each of the uncovered tanks flows back to the liquid accumulation container under the action of gravity, and each of the uncovered tanks is in a state of no liquid level.

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