Liquid cooling energy storage system

Abstract

The utility model discloses a liquid cooling energy storage system, comprising a plurality of battery packs arranged on the same bottom surface; the first liquid cooling plate is arranged on the bottom surface and is attached to the bottom surfaces of the plurality of battery packs; and the second liquid cooling plate is arranged between the opposite side surfaces of the adjacent battery packs, is attached to the opposite side surfaces of the adjacent battery packs and is used for blocking the adjacent battery packs. According to the utility model, the liquid cooling plates are arranged at the bottoms of the battery packs and between the opposite side surfaces of the adjacent battery packs, so that the contact area of the battery packs and the liquid cooling plates can be increased, the liquid cooling effect can be improved, and the temperature difference of different battery packs can be controlled within a smaller range.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid cooling energy storage, in particular to a liquid cooling energy storage system. Background Art

[0002] Battery cells are the energy storage medium in energy storage systems. They can store and release electrical energy, enabling the energy storage system to exchange energy with photovoltaic power plants, power grids, and diesel generators. An energy storage system typically consists of multiple battery clusters, each of which contains multiple battery packs, and each pack contains multiple battery cells. Battery cells exhibit a well-known "barrel effect." For multiple battery cells connected in series, if one reaches the discharge cutoff state first, the other connected cells in the series cannot continue to discharge; if one reaches the charge cutoff state first, the other connected cells in the series cannot continue to charge. Currently, the batteries used in energy storage systems are all lithium-ion batteries. Lithium-ion batteries are significantly affected by temperature. Their internal resistance, discharge plateau, capacity, power, and lifespan are all closely related to temperature. Therefore, temperature differences among all the cells in a battery pack significantly affect the pack's charge and discharge performance. Similarly, temperature differences among the individual battery packs in a battery cluster significantly affect the cluster's charge and discharge performance, which in turn affects the overall energy storage system's charge and discharge performance.

[0003] Current energy storage technologies typically use liquid cooling to control battery temperature and improve temperature uniformity. This approach simultaneously heats and cools multiple battery packs by controlling the power and water inlet and outlet rates of a liquid cooling unit. Liquid cooling plates are installed at the bottom of each battery pack, allowing coolant to circulate within the plates, cooling the battery packs from the bottom.

[0004] However, the capacity of a general energy storage system is relatively large, and the capacity of the battery cells used in the battery pack is also relatively large. The volume of the battery cells used is also relatively large. Only a liquid cooling plate is set at the bottom of the battery pack. The liquid cooling plate has a poor temperature control effect on the entire battery pack. The liquid cooling effect is poor, which will affect the temperature difference of the battery packs within a battery cluster, and thus have a negative impact on the charge and discharge performance of the entire battery cluster. Utility Model Content

[0005] The utility model proposes a liquid-cooled energy storage system to solve the above problems.

[0006] An embodiment of the present utility model discloses a liquid-cooled energy storage system, comprising: a plurality of battery packs arranged on the same bottom surface; a first liquid cooling plate arranged on the bottom surface and in contact with the bottom surfaces of the plurality of battery packs; and a second liquid cooling plate arranged between opposite side surfaces of adjacent battery packs and in contact with opposite side surfaces of adjacent battery packs to block the adjacent battery packs.

[0007] By adopting the above technical solution, the utility model sets a first liquid cooling plate at the bottom of the battery pack and a second liquid cooling plate between the opposite sides of adjacent battery packs, and makes both the first liquid cooling plate and the second liquid cooling plate fit with the battery pack, thereby increasing the contact area between the liquid cooling plate and the battery pack, and separating adjacent battery packs by the liquid cooling plate, which helps to improve the liquid cooling effect and control the temperature difference between different battery packs within a smaller range.

[0008] Optionally, it also includes: multiple battery clusters, each battery cluster containing multiple battery packs; a liquid cooling unit; multiple liquid cooling circulation channels, each liquid cooling circulation channel is connected to the liquid cooling unit, and each battery cluster is provided with an independent matching liquid cooling circulation channel, and coolant flows in the liquid cooling circulation channel. The coolant flows into the liquid cooling circulation channel through the liquid cooling unit to cool the battery cluster, and the coolant then flows back to the liquid cooling unit through the liquid cooling circulation channel.

[0009] Optionally, the diameter of the liquid cooling circulation channel is 2-3 cm.

[0010] Optionally, the first liquid cooling plate and the second liquid cooling plate are perpendicular to each other.

[0011] Optionally, the first liquid cooling plate is in communication with the liquid cooling circulation channel, and the second liquid cooling plate is in communication with the liquid cooling circulation channel, and the coolant may flow into the first liquid cooling plate and the second liquid cooling plate through the liquid cooling circulation channel.

[0012] Optionally, the area of ​​the first liquid cooling plate is the same as the area of ​​the bottom surface of the battery pack.

[0013] Optionally, the area of ​​the second liquid cooling plate is the same as the area of ​​the side surface of the battery pack attached to the second liquid cooling plate.

[0014] Optionally, the number of battery packs in each battery cluster is 4-32.

[0015] Optionally, a temperature sensor is further provided on the battery pack for detecting the temperature of the battery pack to determine the cooling effect of the first liquid cooling plate and the second liquid cooling plate.

[0016] Optionally, a flow rate sensor is also provided on the liquid cooling circulation channel to detect the flow rate of the coolant in the liquid cooling circulation channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a first liquid cooling plate, a second liquid cooling plate, and a battery pack in a liquid-cooled energy storage system according to an embodiment of the present invention is shown;

[0018] Figure 2 A schematic structural diagram of a liquid-cooled energy storage system in an embodiment of the present invention is shown;

[0019] Figure 3A schematic structural diagram of a liquid-cooled energy storage system in the prior art is shown.

[0020] Reference numerals:

[0021] First liquid cooling plate 2, second liquid cooling plate 1, battery pack 3, liquid cooling circulation channel 4, liquid cooling unit 5, water outlet 6, and water return port 7. DETAILED DESCRIPTION

[0022] The following is an explanation of the implementation of the present invention by means of specific specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0023] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0024] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0025] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0027] After careful research into existing technologies, the inventors discovered that existing technologies only provide liquid cooling plates at the bottom of the battery packs in energy storage systems. This cooling effect is poor, resulting in significant temperature differences among battery packs within a battery cluster, which is detrimental to ensuring the cluster's charge and discharge performance. The inventors sought to address this issue.

[0028] refer to Figure 1 The embodiment of the present utility model discloses a liquid-cooled energy storage system, which includes a first liquid cooling plate 2, a second liquid cooling plate 1 and a plurality of battery packs 3. The plurality of battery packs 3 are arranged on the same bottom surface. The first liquid cooling plate 2 is arranged on the bottom surface and is in contact with the bottom surfaces of the plurality of battery packs 3. The first liquid cooling plate 3 cools the battery packs 3 from the bottom of the battery packs 3. The second liquid cooling plate 1 is arranged between the opposite sides of adjacent battery packs 3. The second liquid cooling plate 1 is in contact with the opposite sides of adjacent battery packs 3. The second liquid cooling plate 1 can block the adjacent battery packs 3.

[0029] By adopting the above-mentioned arrangement, the present invention arranges a first liquid cooling plate 2 at the bottom of the battery pack 3, arranges a second liquid cooling plate 1 between the opposite sides of adjacent battery packs 3, and makes the first liquid cooling plate 2 and the second liquid cooling plate 1 fit the battery pack 3. This can increase the contact area between the liquid cooling plate and the battery pack 3, so that the battery pack 3 is in full contact with the first liquid cooling plate 2 and the second liquid cooling plate 1. Such an arrangement can also increase the thermal conductivity between each battery pack and the liquid cooling plate. The higher the thermal conductivity, the higher the temperature transfer efficiency of the coolant and the easier it is to dissipate heat, thereby increasing the temperature change rate of each battery pack 3, for example, speeding up the cooling rate and increasing the temperature uniformity of the battery pack 3. In addition, separating adjacent battery packs 3 with liquid cooling plates can reduce the influence of the temperatures of different battery packs 3, help to further improve the liquid cooling effect, and control the temperature difference between different battery packs within a smaller range.

[0030] In the prior art, when setting up liquid cooling-related equipment, only one liquid cooling unit is used. The liquid outlet and liquid inlet of the liquid cooling unit are connected in series with the liquid inlet pipes, liquid outlet pipes and liquid cooling plates of multiple battery packs of multiple battery clusters, thereby realizing the circulation of cooling liquid among the multiple battery packs. Figure 3 As shown, Figure 3 The schematic diagram of the structure of the prior art liquid cooling energy storage system is shown. The liquid cooling energy storage system includes multiple battery clusters, each of which includes multiple battery packs 3. Figure 3Only three battery clusters are shown, with four battery packs 3 in each battery cluster. The liquid cooling circulation channel 4 connects all the battery packs 3 in series, and there is only one liquid cooling circulation channel 4. The coolant flows from the liquid cooling unit 5 into the liquid cooling circulation channel 4 through the water outlet 6, and then flows back to the liquid cooling unit 5 from the return water outlet 7. In this method of the prior art, one liquid cooling circulation channel 4 flows through multiple battery packs 3 of multiple battery clusters. The channel length is long, which affects the time efficiency of liquid cooling temperature control and makes it difficult to control the flow rate of the coolant. In addition, the number of battery packs 3 in the energy storage system can usually reach dozens or even hundreds. These battery packs 3 are located in different positions in the battery cabinet. In addition, there are also the effects of the battery cells in the battery pack 3 and the design process of the battery pack 3 itself. The heat generation, heat dissipation and ambient temperature of each battery pack 3 during operation are different. The liquid cooling circulation channel 4 flowing through too many battery packs 3 will indirectly bring about mutual temperature influences between different battery packs 3. The temperature of the coolant flowing through each battery pack 3 can also accumulate deviations. The coolant flowing through the battery pack 3 located later in the liquid cooling circulation channel 4 may be hotter than the coolant flowing through the battery pack 3 located earlier in the liquid cooling circulation channel 4. This reduces the cooling effect on subsequent battery packs 3 and hinders controlling the temperature difference between the battery packs within a narrow range. Although the above-mentioned existing technology is relatively low-cost, it is not very effective in controlling the temperature difference between the battery packs. It is difficult to control the temperature difference within a narrow range for both individual battery packs 3 and the entire battery cluster.

[0031] Further, refer to Figure 2 The liquid-cooled energy storage system also includes multiple battery clusters, each of which contains multiple battery packs 3. The liquid-cooled energy storage system also includes a liquid cooling unit 5 and multiple liquid cooling circulation channels 4, each of which is connected to the liquid cooling unit 5. Each battery cluster is provided with an independent matching liquid cooling circulation channel 4, in which coolant flows. The coolant flows into the liquid cooling circulation channel 4 through the liquid cooling unit 5 to cool the battery cluster, and then flows back to the liquid cooling unit 5 through the liquid cooling circulation channel 4.

[0032] Figure 2 The figure shows the structure of the liquid cooling energy storage system, especially the structure of the connection between the liquid cooling circulation channel 4, the battery pack 3 and the liquid cooling unit 5. Figure 2 In this embodiment, only three battery clusters are included, each containing only four battery packs 3 with a battery management system (BMS). Each battery cluster is equipped with its own independent liquid cooling circulation channel 4. That is, if there are three battery clusters, there are also three corresponding liquid cooling circulation channels 4. The liquid cooling circulation channel 4 cools the battery packs 3 within its corresponding battery cluster.

[0033] The liquid cooling unit 5 also includes a water inlet and outlet, which are independently matched with the liquid cooling circulation channel 4. That is, each liquid cooling circulation channel 4 is provided with an independently matched water inlet and outlet for the coolant to flow in or out. The water inlet and outlet include a return water port 7 and a water outlet 6, which are respectively arranged at the two ends of the liquid cooling circulation channel 4. The coolant flows from the water outlet 6 into the liquid cooling circulation channel 4 through the liquid cooling unit 5, and flows through the multiple battery packs 3 in turn to cool the multiple battery packs 3 in the battery cluster. The coolant then flows back to the liquid cooling unit 5 from the return water port 7 to achieve circulation. The liquid cooling circulation channel 4 only cools the battery cluster matched with it and does not flow through other battery clusters.

[0034] With this setup, each battery cluster has its own independently matched liquid cooling circulation channel 4, forming a "one cluster, one liquid cooling" architecture. Compared to the prior art solution where multiple battery clusters utilize only one liquid cooling circulation channel 4, the independently matched liquid cooling circulation channel 4 designed in the present invention cools only one battery cluster. As a result, the number of battery packs 3 in a battery cluster is relatively small, and the length of the liquid cooling circulation channel 4 is relatively short, shortening the coolant return path. With fewer battery packs 3 flowing through it, the resulting temperature accumulation error is small, enabling the temperature of the entire battery cluster to be controlled more quickly within a specified range, helping to control the temperature difference between multiple battery packs 3 within the battery cluster to a smaller range.

[0035] In the above embodiments, a suitable coolant can be selected to cool the battery pack according to actual conditions, and the present invention does not limit this.

[0036] For example, the above-mentioned prior art can only reduce the temperature difference between different battery packs 3 in a battery cluster to a range of more than 5°C, usually within the range of 8-10°C. However, by combining the second cooling plate 1, the first cooling plate 2, and the "one cluster, one liquid cooling" architecture, the present application can control the temperature difference between different battery packs in a battery cluster to a range of less than 5°C, or even within the range of 3-5°C, achieving better temperature control effect.

[0037] Furthermore, different battery clusters have different liquid cooling circulation channels 4. The temperature difference control between each battery cluster can be achieved by controlling the temperature and flow rate of the coolant in each liquid cooling circulation channel 4, which is a dynamic control process during the charging and discharging process of the energy storage system.

[0038] The liquid cooling unit 5 uses 485 communication to communicate with the three-level BMS in the energy storage system. The battery management system (BMS) is divided into different levels: primary, secondary, and tertiary. The primary BMS monitors and balances the voltage, current, and temperature of a single battery pack 3. The secondary BMS manages a battery cluster consisting of multiple battery packs 3. The tertiary BMS can monitor and manage multiple battery clusters.

[0039] In the energy storage system, the temperature information of the battery pack 3 is first sent to the secondary BMS through the primary BMS. The secondary BMS and the tertiary BMS exchange information via CAN communication, which helps to accurately grasp the temperature differences between different battery packs 3, thereby adjusting the flow rate or temperature of the coolant.

[0040] Preferably, a temperature sensor (not shown in the figure) may be provided on the battery pack 3 to detect the temperature of the battery pack 3 to determine the cooling effect of the first liquid cooling plate 2 and the second liquid cooling plate 1. A temperature sensor may be provided on each battery pack 3 to accurately monitor the temperature of each battery pack 3. Preferably, a flow rate sensor (not shown in the figure) may be provided on the liquid cooling circulation channel 4 to detect the flow rate of the coolant in the liquid cooling circulation channel 4. Providing a temperature sensor and a flow rate sensor helps to more accurately control the flow rate or temperature of the coolant, thereby controlling the cooling effect of the coolant on different battery packs 3 in a battery cluster or different battery packs 3 in different battery clusters, helping to reduce the temperature difference of the battery pack 3, improve the temperature uniformity of the entire cluster, and improve the consistency of the entire energy storage system.

[0041] Furthermore, the diameter of the liquid cooling circulation channel 4 is 2-3 cm, which helps to ensure that the coolant can flow smoothly, and the amount of coolant is sufficient to cool the multiple battery packs 3 in the battery cluster.

[0042] Furthermore, the first and second liquid cooling plates 2 and 1 are perpendicular to each other. This arrangement makes the structure of the first and second liquid cooling plates 2 and 1 more robust, and the combined structure of the first and second liquid cooling plates 2 and 1 and the battery pack 3 more robust. The arrangement of the first and second liquid cooling plates 2 and 1 also matches the structure of the battery pack 3, making them less susceptible to damage.

[0043] In the above embodiments, the first liquid cooling plate 2 is connected to the liquid cooling circulation channel 4, and the second liquid cooling plate 1 is connected to the liquid cooling circulation channel 4. The coolant can flow into the first liquid cooling plate 2 and the second liquid cooling plate 1 through the liquid cooling circulation channel 4 to cool the battery pack 3.

[0044] Furthermore, the area of ​​the first liquid cooling plate 2 is the same as the bottom area of ​​the battery pack 3. There can be multiple first liquid cooling plates 2, one for each battery pack 3. Setting the area of ​​the first liquid cooling plate 2 equal to the bottom area of ​​the battery pack 3 prevents the first liquid cooling plate 2 from being too large, contributing to a more compact structure for the liquid-cooled energy storage system and lowering costs. The area of ​​the first liquid cooling plate 2 can also be slightly larger than the bottom area of ​​the battery pack 3.

[0045] In other embodiments, multiple battery packs 3 in a battery cluster may share one first liquid cooling plate 2 . In this case, it is only necessary that the first liquid cooling plate 2 can completely fit with the bottom surfaces of the multiple battery packs 3 .

[0046] Furthermore, the area of ​​the second liquid cooling plate 1 is the same as the area of ​​the side of the battery pack 3 attached to the second liquid cooling plate 1. This configuration helps prevent the area of ​​the second liquid cooling plate 1 from being too large, thereby reducing costs.

[0047] In the above embodiments, the number of battery packs 3 in each battery cluster is 4-32. If the number of battery packs 3 varies, different arrangements can be used, as long as the second liquid cooling plate 1 is positioned between opposing sides of adjacent battery packs 3 and is in contact with opposing sides of adjacent battery packs 3.

[0048] The liquid-cooled energy storage system of the present invention increases the contact area between the battery pack 3 and the liquid cooling plate, alleviating the problem of the battery pack 3 and the cells therein reacting too slowly to the temperature of the coolant. This allows different battery packs 3 and the cells therein to quickly reach a suitable temperature environment, helping to improve temperature control efficiency, such as cooling efficiency. The temperature differences between different battery packs, cells within different battery packs, and different battery clusters can be controlled to a smaller range, helping to enhance the charge and discharge performance of the entire energy storage system and extend its service life.

[0049] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A liquid-cooled energy storage system, characterized in that: include: Multiple battery packs are arranged on the same bottom surface; a first liquid cooling plate, disposed on the bottom surface and in contact with the bottom surfaces of the plurality of battery packs; The second liquid cooling plate is disposed between opposite side surfaces of adjacent battery packs and is in contact with the opposite side surfaces of adjacent battery packs to block the adjacent battery packs.

2. The liquid-cooled energy storage system according to claim 1, characterized in that: Also includes: a plurality of battery clusters, each of the battery clusters comprising the plurality of battery packs; Liquid cooling unit; Multiple liquid cooling circulation channels, each of which is connected to the liquid cooling unit, and each battery cluster is provided with an independently matched liquid cooling circulation channel. Coolant flows through the liquid cooling circulation channel, and the coolant flows into the liquid cooling circulation channel through the liquid cooling unit to cool the battery cluster, and the coolant then flows back to the liquid cooling unit through the liquid cooling circulation channel.

3. The liquid-cooled energy storage system according to claim 2, characterized in that: The diameter of the liquid cooling circulation channel is 2-3 cm.

4. The liquid-cooled energy storage system according to claim 1, wherein: The first liquid cooling plate and the second liquid cooling plate are perpendicular to each other.

5. The liquid-cooled energy storage system according to claim 2, characterized in that: The first liquid cooling plate is in communication with the liquid cooling circulation channel, and the second liquid cooling plate is in communication with the liquid cooling circulation channel. The coolant can flow into the first liquid cooling plate and the second liquid cooling plate through the liquid cooling circulation channel.

6. The liquid-cooled energy storage system according to claim 1, characterized in that: The area of ​​the first liquid cooling plate is the same as the area of ​​the bottom surface of the battery pack.

7. The liquid-cooled energy storage system according to claim 1, characterized in that: The area of ​​the second liquid cooling plate is the same as the area of ​​the side surface of the battery pack attached to the second liquid cooling plate.

8. The liquid-cooled energy storage system according to claim 1, wherein: Also includes: A plurality of battery clusters, each of the battery clusters comprising the plurality of battery packs; the number of the battery packs in each of the battery clusters is 4-32.

9. The liquid-cooled energy storage system according to claim 1, wherein: The battery pack is further provided with a temperature sensor for detecting the temperature of the battery pack to determine the cooling effect of the first liquid cooling plate and the second liquid cooling plate.

10. The liquid-cooled energy storage system according to claim 2, wherein: The liquid cooling circulation channel is also provided with a flow rate sensor for detecting the flow rate of the coolant in the liquid cooling circulation channel.

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