A battery pack and a temperature control method

Abstract

The present application provides a battery pack and a temperature control method. The battery pack includes battery cells, a box body, a support assembly, and a lifting assembly. The box body has a receiving cavity, is provided with a liquid inlet and a liquid outlet, and a heat exchange medium is provided in the receiving cavity. The support assembly is disposed in the receiving cavity and includes a support plate and a support member. The support plate can abut against the support member, and the support plate can divide the receiving cavity in the height direction of the battery pack into a first cavity and a second cavity. The battery cells are disposed on the support plate and located in the first cavity. The lifting assembly is used to drive the support plate to move in the height direction of the battery pack and switch between a low position state and a high position state. When the support plate is in the low position state, the support plate abuts against the support member, and the first cavity and the second cavity are relatively closed. When the support plate is in the high position state, there is a gap between the support plate and the support member, and the first cavity and the second cavity communicate with each other, so as to reduce the power consumption of the battery pack for heat dissipation.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage, and particularly to a battery pack and a temperature control method. Background Art

[0002] A battery is a commonly used electrical energy storage device. To meet the need for higher power, in the prior art, multiple batteries are usually combined to form a battery pack for operation. During the charging or discharging process of the battery, heat is generated. If the heat is not controlled, it may lead to a shortened battery life or even thermal runaway. To control the operating temperature of the battery, an external cooling system must be set up for heat dissipation. The liquid cooling technology adopted in the prior art dissipates heat by immersing the battery in a coolant, but the power consumption of the cooling system is very high, which is not conducive to the overall energy saving of the battery pack. Summary of the Invention

[0003] In view of this, the present application provides a battery pack and a temperature control method to facilitate solving the problem of high power consumption required for cooling the battery pack in the prior art.

[0004] The present application provides a battery pack, and the battery pack includes:

[0005] a battery cell, and the battery pack includes a plurality of the battery cells;

[0006] a box body, the box body has a receiving cavity, the box body is provided with a liquid inlet and a liquid outlet, and a heat exchange medium is provided in the receiving cavity;

[0007] a support assembly, the support assembly is arranged in the receiving cavity, the support assembly includes a support plate and a support member, the support plate can abut against the support member, the support plate can divide the receiving cavity into a first cavity and a second cavity along the height direction of the box body, the first cavity is located above the second cavity, and the battery cells are arranged on the support plate and located in the first cavity;

[0008] a lifting assembly, the lifting assembly is connected to the support plate, and the lifting assembly is used to drive the support plate to move along the height direction of the battery pack and switch between a low position state and a high position state;

[0009] When the support plate is in the low position state, the support plate abuts against the support member, the first cavity and the second cavity are relatively closed, and when the support plate is in the high position state, there is a gap between the support plate and the support member, and the first cavity and the second cavity communicate with each other.

[0010] The battery pack provided by the embodiment of the present application can adjust the position state of the support plate according to the actual cooling requirements of the battery pack. When the heat dissipation requirement of the battery pack is small, the support plate is set in a low position state, and the heat dissipation need of the battery pack can be met with relatively low power consumption. When the heat dissipation requirement of the battery pack is large, the support plate is set in a high position state to improve the heat dissipation efficiency of the battery pack and also meet the actual heat dissipation requirement of the battery pack. The support assembly can also finely adjust the lifting height of the support plate, thereby controlling the gap size between the support plate and the support member, achieving a more precise balance adjustment between the cooling power consumption and the cooling efficiency of the battery pack, which is beneficial to reducing the power consumption during the cooling of the battery pack.

[0011] In a possible implementation manner, the support plate has a plurality of heat dissipation holes, the heat dissipation holes are correspondingly arranged with the battery cells, and a part of the projection of the battery cells along the height direction of the battery pack coincides with the projection of the heat dissipation holes.

[0012] In a possible implementation manner, the cross-sectional area of the heat dissipation holes gradually decreases along the direction close to the battery cells.

[0013] In a possible implementation manner, the support plate has pressure equalizing holes, and the projection of the pressure equalizing holes along the height direction of the battery pack does not coincide with the support member.

[0014] In a possible implementation manner, the projection area of the support plate along the height direction of the battery pack is smaller than the projection area of the bottom wall of the box body, and the projection of the support assembly along the height direction of the battery pack coincides with the projection of the bottom wall of the box body.

[0015] In a possible implementation manner, the lifting assembly includes a driving member and a lifting member, the driving member can drive the lifting member to move along the height direction of the battery pack, and the lifting member is connected to the support plate.

[0016] In a possible implementation manner, the battery pack includes a partition plate, the partition plate is installed on the support plate and located in the first cavity, one end of the partition plate is connected to the side wall of the box body, there is a gap between the other end of the partition plate and the side wall of the box body, and the liquid inlet and the liquid outlet are respectively located on both sides of the partition plate.

[0017] The present application provides a temperature control method, and the temperature control method includes:

[0018] Detecting the temperature of each measurement point to obtain the measurement point temperature;

[0019] Calculating the average temperature of the battery pack according to the temperatures of multiple measurement points in the battery pack;

[0020] Calculate the difference between the temperature of each measurement point and the average temperature according to the average temperature, and obtain the temperature difference of each measurement point;

[0021] Calculate the maximum temperature difference according to the highest temperature and the lowest temperature among the temperatures of each measurement point;

[0022] Adjust the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference;

[0023] In a possible implementation manner, the adjusting the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference includes:

[0024] When there is a temperature difference greater than or equal to the first temperature threshold, adjust the support plate of the corresponding battery pack to the high position state;

[0025] When all the temperature differences are less than the first temperature threshold and the maximum temperature difference is greater than or equal to the second temperature threshold, adjust the support plate of the corresponding battery pack to the high position state;

[0026] When all the temperature differences are less than the first temperature threshold and the maximum temperature difference is less than the second temperature threshold, adjust the support plate of the corresponding battery pack to the low position state.

[0027] In a possible implementation manner, after adjusting the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference, the method further includes:

[0028] Detect the number of battery packs with the support plate in the high position state and the low position state respectively;

[0029] When the number of battery packs in the high position state is greater than the number of battery packs in the low position state, increase the cooling power of the liquid chiller;

[0030] When the number of battery packs in the high position state is less than or equal to the number of battery packs in the low position state and there is a battery pack in the high position state, the cooling power of the liquid chiller remains unchanged;

[0031] When all the battery packs are in the low position state, reduce the cooling power of the liquid chiller. Description of the Drawings

[0032] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0033] Figure 1 Schematic diagram of the internal structure of a battery pack provided by an embodiment of the present application;

[0034] Figure 2 Cross-sectional view of a battery pack provided by an embodiment of the present application;

[0035] Figure 3 Schematic diagram of the structure of a support plate provided by an embodiment of the present application;

[0036] Figure 4 Schematic diagram of the structure of a support plate installed inside a box body provided by an embodiment of the present application;

[0037] Figure 5 Schematic diagram of the structure of a support member provided by an embodiment of the present application;

[0038] Figure 6 Partial cross-sectional view of a battery pack provided by an embodiment of the present application;

[0039] Figure 7 Schematic diagram of the structure of a partition plate provided by an embodiment of the present application;

[0040] Figure 8 Schematic diagram of the structure of the battery pack in another specific embodiment provided by an embodiment of the present application;

[0041] Figure 9 Flow chart of a temperature control method provided by an embodiment of the present application.

[0042] Explanation of reference numerals:

[0043] 1 - Box body;

[0044] 11 - Accommodating cavity;

[0045] 111 - First cavity;

[0046] 112 - Second cavity;

[0047] 12 - Liquid inlet;

[0048] 13 - Liquid outlet;

[0049] 2 - Battery cell;

[0050] 3 - Support assembly;

[0051] 31 - Support plate;

[0052] 311 - Heat dissipation holes;

[0053] 312 - Pressure equalizing holes;

[0054] 32 - Support member;

[0055] 4 - Lifting assembly;

[0056] 41 - Driving member;

[0057] 42 - Lifting member;

[0058] 5 - Partition board;

[0059] 51 - Gasket. Detailed implementation manners

[0060] For a better understanding of the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0061] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0062] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0063] It should be understood that the term " / and / " used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, a and / or b may represent: a exists alone, a and b exist simultaneously, and b exists alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0064] Such as Figure 1As shown in the figure, an embodiment of the present application provides a battery pack. The battery pack includes a box body 1. The box body 1 has a receiving cavity 11. A plurality of battery cells 2 are arranged inside the box body 1. The box body 1 is provided with a liquid inlet 12 and a liquid outlet 13, and there is a heat exchange medium in the receiving cavity 11. The heat exchange medium is a fluid. For example, the heat exchange medium is a liquid that can flow. The heat exchange medium can enter the receiving cavity 11 from the liquid inlet 12 and discharge from the liquid outlet 13 from the receiving cavity 11, so as to realize the flow of the heat exchange medium inside the receiving cavity 11. The liquid inlet 12 and the liquid outlet 13 can be connected to other external devices, such as a water pump, so as to provide power for the flow cycle of the heat exchange medium. Through the circulating flow of the heat exchange medium, the heat generated when the battery cells 2 work can be taken away, thereby improving the safety of the battery pack and increasing the service life of the battery pack.

[0065] When the heat exchange medium flows in the receiving cavity 11, the temperature inside the receiving cavity 11 can be adjusted. In particular, the heat generated when the battery cells 2 work can be taken away, so that the battery cells 2 can be kept in a safe state and have higher working efficiency. In addition, the heat exchange medium can fill the entire receiving cavity 11, so that the battery cells 2 are completely immersed in the heat exchange medium, thereby improving the heat dissipation efficiency. The heat exchange medium should be an insulating material. When the heat exchange medium contacts the battery cells 2, it will not cause the battery cells 2 to short-circuit, improving the overall safety of the battery pack. When the temperature of the battery pack is too high and needs to be reduced, the heat exchange medium is used to take away the heat. When the temperature of the battery pack is low and needs to be increased, the battery pack can also be heated through the heat exchange medium, so that the battery pack reaches a suitable working temperature. For example, when the battery pack operates in a lower environment, the battery pack with a lower temperature can be heated by setting a heat exchange medium with a higher temperature. It should be understood that the heat exchange described in the present application can be used to cool or heat the battery pack. Some embodiments in the present application describe one of the cooling or heating situations, because the principles of heating and cooling are both realized by the heat exchange medium circulating in the box body for heat exchange, and the principles of the two heating or cooling are similar. Therefore, when describing one situation, the other situation will not be elaborated.

[0066] A support assembly 3 and a lifting assembly 4 are arranged inside the receiving cavity 11. The support assembly 3 includes a support plate 31 and a support member 32. The support plate 31 can be in a flat plate shape, so as to provide a large support area for arranging a plurality of battery cells 2. The lifting assembly 4 is connected to the support plate 31, and the lifting assembly 4 can drive the support plate 31 to move in the height direction of the battery pack. As Figure 1As shown, the X direction is the length direction of the battery pack, the Y direction is the width direction of the battery pack, and the Z direction is the height direction of the battery pack. Along the height direction of the battery pack, the support member 32 is located at the bottom of the support plate 31. The support plate 31 can abut against the support member 32 to realize the support function for the support plate 31. Therefore, the support plate 31 does not directly contact the bottom wall of the box body 1. The support plate 31 can divide the accommodation cavity 11 into a first cavity 111 and a second cavity 112. Along the height direction of the battery pack, the first cavity 111 is located above the second cavity 112. The battery cell 2 is arranged on the support plate 31 and is located in the first cavity 111. When the lifting assembly 4 drives the support plate 31 to move, the support plate 31 can drive the battery cell 2 to move synchronously.

[0067] As Figure 2As shown, the lifting assembly 4 can drive the support plate 31 to switch between the high position state and the low position state. When the support plate 31 is in the low position state, the support plate 31 abuts against the support member 32, and there is no gap between the support plate 31 and the support member 32, so as to realize the relative closure between the first cavity 111 and the second cavity 112. The heat exchange medium has a relatively fast flow rate and circulation rate in the first cavity 111, and the heat exchange medium does not flow and circulate in the second cavity 112, or the heat exchange medium flows and circulates in the second cavity 112 at an extremely slow speed, so as to realize a relatively small flow resistance of the heat exchange medium in the accommodation cavity 11, which is convenient for circulating the heat exchange medium through the liquid inlet 12 and the liquid outlet 13, and keeps the power consumption required for circulating the heat exchange medium at a relatively low state, which is beneficial to reducing the power consumption of the battery pack cooling work. For example, it can reduce the power consumption required when the water pump or valve connected to the liquid inlet 12 and the liquid outlet 13 works. When the support plate 31 is in the high position state, the support plate 31 and the support member 32 are separated from each other, and there is a gap between them. The first cavity 111 and the second cavity 112 communicate with each other. The heat exchange medium in the first cavity 111 and the heat exchange medium in the second cavity 112 can flow and circulate, improving the range and volume of the heat exchange medium exchange, and thus improving the heat dissipation efficiency of the battery pack. Therefore, the battery pack provided by the embodiment of the present application can adjust the position state of the support plate 31 according to the actual cooling requirements of the battery pack. When the heat dissipation requirement of the battery pack is small, the support plate 31 is set in the low position state, and the heat dissipation requirement of the battery pack can be met with relatively small power consumption. When the heat dissipation requirement of the battery pack is large, the support plate 31 is set in the high position state to improve the heat dissipation efficiency of the battery pack, and the actual heat dissipation requirement of the battery pack can also be met. The support assembly 3 can also finely adjust the lifting height of the support plate 31, so as to control the size of the gap between the support plate 31 and the support member 32, realize a more precise balance adjustment between the cooling power consumption and the cooling efficiency of the battery pack, which is beneficial to reducing the power consumption during the cooling of the battery pack and realizing the overall energy saving of the battery pack. The battery pack can be provided with sensors to monitor the temperature of the battery cell 2 during operation. By setting up electronic components, the automatic control of the position of the support plate 31 can be realized according to the monitored temperature, or it can also be manually controlled.

[0068] The lifting assembly 4 can drive the support plate 31 to move linearly along the height direction of the battery pack, or can drive the support plate 31 to rotate while moving along the height direction of the battery pack, as long as the first cavity 111 and the second cavity 112 can be communicated. The support member 32 can be in a form extending along the length direction or the width direction of the battery pack, so that the support member 32 can provide a relatively large support area for supporting the support plate 31 and improve the stability of the support plate 31. As Figure 1 shown, the box body 1 is usually set in the form of a polyhedron, such as a cuboid or a cube, etc. For the convenience of showing the internal structure of the battery pack, Figure 1The top cover of the box body 1 therein is omitted and not shown. The bottom wall of the box body 1 is a plane, which is convenient for placing and installing the battery pack. It should be understood that the relative enclosure of the first cavity 111 and the second cavity 112 may not be a strictly complete enclosure. Due to errors in the dimensions or flatness between the support plate 31 and the support member 32, it may cause the support plate 31 to fail to achieve a completely sealed effect when it abuts against the support member 32. There is still a certain small gap between the support plate 31 and the support member 32 through which the heat exchange medium can pass, but this gap does not affect the partitioning effect of the support plate 31. Generally, the first cavity 111 and the second cavity 112 are still in a relatively partitioned state. At this time, the heat exchange medium exchange speed between the first cavity 111 and the second cavity 112 is very slow. The heat exchange medium mainly circulates and flows in the first cavity 111, and the heat exchange medium flow and circulation speed in the second cavity 112 is extremely slow.

[0069] The box body 1 can be provided with a plurality of liquid inlets 12 and liquid outlets 13. For example, liquid inlets 12 and liquid outlets 13 are respectively provided in the first cavity 111 and the second cavity 112, so as to achieve a faster heat exchange medium circulation. When the heat dissipation requirement of the battery pack is small, the support plate 31 can be set in a low position state, and the liquid inlets 12 and liquid outlets 13 communicated with the second cavity 112 can be closed, or its operating efficiency can be reduced, and only the liquid inlets 12 and liquid outlets 13 communicated with the first cavity 111 are opened for the circulation of the heat exchange medium, so as to reduce the power consumption required for cooling. When the heat dissipation requirement of the battery pack is large, the support plate 31 is set in a high position state, and all the liquid inlets 12 and liquid outlets 13 are opened for operation to improve the heat dissipation efficiency.

[0070] The box body 1 can also be provided with only one liquid inlet 12 and one liquid outlet 13, which is beneficial to reducing the heat dissipation power consumption, simplifying the structure of the battery pack and reducing the manufacturing cost. When the support plate 31 is in a high position state, the first cavity 111 and the second cavity 112 are communicated with each other, and the heat exchange medium circulation in the two cavities can be realized only through one liquid inlet 12 and one liquid outlet 13. When the support plate 31 is in a low position state, according to the setting positions of the liquid inlet 12 and the liquid outlet 13, only the heat exchange medium circulation of the first cavity 111 or the second cavity 112 is realized, so as to reduce the flow resistance and power consumption.

[0071] As Figure 3 shown, in a possible implementation manner, the support plate 31 has a plurality of heat dissipation holes 311, the heat dissipation holes 311 are correspondingly arranged with the battery cells 2, and a part of the projection of the battery cells 2 along the height direction of the battery pack coincides with the projection of the heat dissipation holes 311.

[0072] When the battery cell 2 is disposed on the support plate 31, the heat dissipation holes 311 are located at the bottom of the battery cell 2. The heat exchange medium in the second cavity 112 can contact the bottom wall of the battery cell 2 through the heat dissipation holes 311, thereby improving the cooling effect on the battery. The shape of the heat dissipation holes 311 can be set to a circular shape, an oval shape, a square shape, etc., and no specific limitation is made here. The bottom of the battery cell 2 should cover the heat dissipation holes 311, so as to maximize the heat exchange effect of the heat dissipation holes 311 on the battery cell 2. One heat dissipation hole 311 or multiple heat dissipation holes 311 can be provided at the bottom of the same battery cell 2.

[0073] As Figure 6 shown, in a possible implementation manner, the cross-sectional area of the heat dissipation holes 311 in the battery pack height direction Z gradually decreases in the direction close to the battery cell 2.

[0074] The cross-sectional shape of the heat dissipation holes 311 can be set to a conical shape. Along the height direction of the battery pack, the opening cross-sectional area of the heat dissipation holes 311 on the side close to the battery cell 2 is smaller than the opening cross-sectional area of the heat dissipation holes 311 on the side far from the battery cell 2. The heat exchange medium in the second cavity 112 can contact the bottom of the battery cell 2 through the heat dissipation holes 311 to take away the heat of the battery cell 2 and improve the heat dissipation efficiency of the battery cell 2. Since the support plate 31 has a certain thickness, the heat dissipation holes 311 can be regarded as tubular channels with a small length. The cross-sectional areas of the heat dissipation holes 311 at different positions along the height direction of the battery cell 2 are different. Specifically, the cross-sectional area of the heat dissipation holes 311 gradually decreases in the direction close to the battery cell 2. The inner wall of the heat dissipation holes 311 can be set to an inclined state or a stepped state to be used to realize the change of the through-hole cross-sectional area. According to the basic principle of fluid mechanics, when the heat exchange medium flows through the heat dissipation holes 311 in the direction close to the battery cell 2, due to the change of the cross-sectional area of the heat dissipation holes 311, its flow velocity will increase, so that the heat dissipation effect on the battery cell 2 can be further enhanced.

[0075] In a possible implementation manner, the support plate 31 has pressure equalizing holes 312, and the projection of the pressure equalizing holes 312 in the battery pack height direction does not coincide with the support member 32.

[0076] When the support plate 31 switches between the high position state and the low position state, it needs to move along the height direction of the battery pack. Since there is a heat exchange medium inside the accommodation cavity 11, the support plate 31 will be subject to resistance when moving. Setting the pressure equalizing holes 312 can achieve the effect of connecting the first cavity 111 and the second cavity 112, realizing the balance of pressure, reducing the resistance suffered by the support plate 31 when moving, being beneficial to reducing the power consumption when driving the support plate 31, and facilitating increasing the movement speed of the support plate 31 and reducing the time required for the support plate 31 to switch between the high position state and the low position state. The pressure equalizing holes 312 can be set at the edge position of the support plate 31, so as to avoid the support member 32, so that when the support plate 31 is in the low position state and abuts against the support member 32, the pressure equalizing holes 312 will not be blocked by the support member 32. Multiple pressure equalizing holes 312 can be provided on the support plate 31, and the multiple pressure equalizing holes 312 are respectively arranged on both sides of the support plate 31, so as to improve the effect of reducing flow resistance. The shape of the pressure equalizing holes 312 can be rectangular or circular, etc., and no specific limitation is made here.

[0077] In a possible implementation manner, the projected area of the support plate 31 along the height direction of the battery pack is smaller than the projected area of the bottom wall of the box body 1, and the projection of the support assembly 3 along the height direction of the battery pack coincides with the projection of the bottom wall of the box body 1.

[0078] The support plate 31 is set in a flat plate form, which is convenient for supporting the battery cells 2 and separating the accommodation cavity 11. The area of the support plate 31 can be slightly smaller than the area of the bottom wall of the box body 1. Therefore, the projected area of the support plate 31 along the height direction of the battery pack is smaller than the projected area of the bottom wall of the box body 1, so that there is a gap between the support plate 31 and at least one side wall of the box body 1. When the support plate 31 and the support member 32 are separated, it is convenient for the first cavity 111 and the second cavity 112 to communicate. The support member 32 can be set at a position where the projection of the bottom wall of the box body 1 does not coincide with the projection of the support plate 31, and the projection of the support member 32 covers the part of the projection of the bottom wall of the box body 1 that does not coincide with the projection of the support plate 31. Therefore, when the support plate 31 is in the low position state, the support plate 31 and the support member 32 are in abutting cooperation to realize the relative closure of the first cavity 111 and the second cavity 112.

[0079] In a possible implementation manner, the liquid inlet 12 and the liquid outlet 13 are communicated with the first cavity 111.

[0080] The liquid inlet 12 and the liquid outlet 13 are arranged on the outer wall of the box body 1 corresponding to the first cavity 111, enabling the heat exchange medium in the first cavity 111 to circulate faster. Since the battery cell 2 is arranged in the first cavity 111, the heat dissipation efficiency of the battery cell 2 can be improved. When the support plate 31 is in the high position state, the first cavity 111 and the second cavity 112 are in communication with each other, and the liquid inlet 12 and the liquid outlet 13 can directly exchange and circulate the heat exchange medium in the first cavity 111. Since the heat exchange medium in the first cavity 111 and the second cavity 112 can flow through each other, the flow in the second cavity 112 is indirectly realized. When the support plate 31 is in the low position state, the first cavity 111 and the second cavity 112 are relatively closed. The liquid inlet 12 and the liquid outlet 13 circulate and exchange the heat exchange medium in the first cavity 111, and the heat exchange medium in the second cavity 112 can be regarded as not flowing and exchanging or circulating at an extremely slow speed, thereby greatly reducing the resistance when the heat exchange medium flows and reducing the power consumption of the battery pack for cooling and heat dissipation.

[0081] In a possible implementation manner, the support assembly 3 includes two support members 32, and the two support members 32 are respectively located on both sides of the support plate 31.

[0082] The support members 32 can be arranged on both sides of the support plate 31 along the length direction and the width direction of the battery pack, thereby improving the stability of the support plate 31. Or multiple support members 32 can also be arranged on the battery pack to support the support plate 31 at the middle position of the support plate 31.

[0083] As Figure 2 shown, in a possible implementation manner, the lifting assembly 4 includes a driving member 41 and a lifting member 42. The driving member 41 can drive the lifting member 42 to move along the height direction of the battery pack, and the lifting member 42 is connected to the support plate 31.

[0084] One end of the lifting member 42 is connected to the driving member 41, and the other end is connected to the support plate 31. When the driving member 41 drives the lifting member 42 to move along the height direction of the battery pack, the support plate 31 can move with the lifting member 42, thereby switching between the high position state and the low position state. The side of the lifting member 42 connected to the support plate 31 can be set as a plane, which can improve the connection stability between the lifting member 42 and the support plate 31. The driving member 41 and the lifting member 42 can be connected by a rack or a pulley, etc., and no specific limitation is made here. Multiple lifting assemblies 4 can be arranged on the battery pack. For example, support assemblies 3 can be respectively arranged at the corner positions of the support plate 31, thereby improving the speed and stability when the support plate 31 moves and reducing the resistance of the heat exchange medium flowing in the second cavity.

[0085] In a possible implementation manner, the material of the heat exchange medium is one of mineral oil, vegetable oil, silicone oil or synthetic oil.

[0086] The heat exchange medium should be fluid and insulating, capable of improving the heat dissipation efficiency through flow circulation and having no impact on the working safety of the circuit inside the battery pack. Mineral oil can be a mixture composed of compounds such as alkanes, naphthenic saturated hydrocarbons, and aromatic unsaturated hydrocarbons, such as transformer oil. Vegetable oil can be castor oil, linseed oil, or tung oil, etc. Synthetic oil is made from ethylene, propylene, etc. dispersed from the gas of crude oil or natural gas, and is refined through polymerization, catalysis, and other reactions. The performance of synthetic oil can be artificially controlled to be excellent. The silicone oil is insulating silicone oil, such as methyl silicone oil, etc. Since the density of various insulating oils is relatively large, the flow resistance during the circulation process is also relatively large. The battery pack provided by the embodiments of the present application can control the position of the support plate 31, thereby changing the circulation flow range of the heat exchange medium inside the accommodation cavity 11 to control the flow resistance of the heat exchange medium inside the accommodation cavity 11. When the heat dissipation requirement of the battery pack is low, the circulation range and flow resistance of the heat exchange medium inside the accommodation cavity 11 are reduced to achieve the effect of energy conservation.

[0087] In a possible implementation manner, a flow guide plate can be provided on the bottom wall of the box body 1. The flow guide plate protrudes along the height direction of the battery pack to form a flow channel. By providing a plurality of flow channels, a flow channel is formed inside the second cavity 112 for guiding the flow of the heat exchange medium. The flow guide plate can cause a turbulent effect on the heat exchange medium, disturbing the laminar flow layer in contact with the bottom of the battery cell 2, so that the flow layer far from the bottom of the battery cell 2 can also receive more heat, improving the heat dissipation efficiency.

[0088] As Figure 7 shown, in a possible implementation manner, the battery pack includes a partition plate 5. The partition plate 5 is installed on the support plate 31 and is located in the first cavity 111. One end of the partition plate 5 is connected to the side wall of the box body 1, and the other end has a gap with the side wall of the box body 1. The liquid inlet 12 and the liquid outlet 13 are respectively located on both sides of the partition plate 5.

[0089] The liquid inlet 12 and the liquid outlet 13 of the box body 1 can be arranged on the same side wall of the box body 1. The position where the partition plate 5 is connected to the side wall of the box body 1 is located between the liquid inlet 12 and the liquid outlet 13. Therefore, the partition plate 5 can relatively separate the liquid inlet 12 and the liquid outlet 13. The other end of the partition plate 5 is not connected to the box body 1. Therefore, the heat exchange medium can flow around the partition plate 5. When the support plate 31 is in the high position state, the top of the partition plate 5 can abut against the top wall of the box body 1. The heat exchange medium is injected into the box body 1 from the liquid inlet 12, and the heat exchange medium needs to flow around the side of the partition plate 5 to reach the liquid outlet 13 and be discharged, so that the flow path of the heat exchange medium becomes a curved shape, increasing the flow distance and flow range of the heat exchange medium, reducing the flow dead zone, and thus improving the heat exchange efficiency. The height of the partition plate 5 is set with reference to the height of the battery cell 2. The height of the partition plate 5 should be the same as or slightly higher than the height of the battery cell 2, so as to leave sufficient space for the arrangement and setting of the battery cell 2 and be able to abut against the top wall of the box body 1. In order to facilitate the display of the internal structure of the box body 1, the top wall of the box body 1 is not shown in the figure, and the top wall of the box body 1 plays a sealing role. The battery pack can change the shape of the flow channel by arranging a plurality of partition plates 5. The connection positions of the plurality of partition plates 5 are respectively located on two opposite side walls of the box body 1, so as to form a flow channel similar to a snake shape, so that the flow path of the heat exchange medium includes a plurality of bending sections, thereby further increasing the flow range of the heat exchange medium and improving the heat exchange effect.

[0090] As Figure 7 and Figure 8 shown, in a possible implementation manner, a gasket 51 is arranged on the side of the partition plate 5 away from the support plate 31. The gasket 51 is parallel to the support plate 31. When the support plate 31 is in the high position state, the gasket 51 abuts against the top wall of the box body 1.

[0091] The gasket 51 and the partition plate 5 are arranged in a mutually perpendicular direction, and the two are connected to form a "T" shape approximately. The gasket 51 can increase the contact area between the partition plate 5 and the top wall of the box body 1, thereby improving the sealing performance of the partition by the partition plate 5 and reducing the possibility of the heat exchange medium flowing from the sealed position.

[0092] When the support plate 31 is in the high position state, there is a preset distance from the top wall of the box body 1 in the height direction of the battery pack. The preset distance is similar to or equal to the height dimension of the partition plate 5, so that when the support plate 31 is in the high position state, the support plate 31 can abut against the top wall of the box body 1, so as to realize the partition function and form a flow channel. As Figure 8As shown, the black dotted arrow in the figure is the schematic direction of the heat exchange medium flow, and the shape of the flow channel is approximately "U"-shaped, which extends the flow distance of the heat exchange medium and increases the flow range of the heat exchange medium, thereby improving the heat exchange effect. The partition plate 5 and the gasket 51 can move with the support plate 31. When the support plate 31 switches between the high position state and the low position state, the partition plate 5 can switch between the two states of separating the first cavity 111 to form a flow channel and releasing the separation.

[0093] When the support plate 31 is in a high position, the partition plate 5 and the gasket 51 can abut against the top wall of the box body 1 as the support plate 31 moves, thereby dividing the flow channel of the first cavity 111 into two interconnected parts and forming a flow channel, and the heat exchange medium can circulate along the flow channel to increase the flow range of the heat exchange medium. Furthermore, the support plate 31 and the support member 32 are separated from each other, and the first cavity 111 and the second cavity 112 are connected to each other. Therefore, when the support plate 31 is in a high position, the heat exchange medium can have a larger circulation space and a larger flow distance in the box body 1, thereby achieving a stronger heat exchange capacity and meeting the higher heat exchange needs in actual working operation.

[0094] When the support plate 31 is in a low position, the partition plate 5 and the gasket 51 connected to the support plate 31 will be in a lower position along with the support plate 31, so the partition plate 5 and the gasket 51 will be separated from the top wall of the box body 1, and the heat exchange medium can flow relatively freely inside the box body 1, thereby reducing the flow resistance, and further cooperating with the support plate 31 to separate the box body 1 as a whole into two upper and lower parts, reducing the flow range of the heat exchange medium, thereby reducing the energy consumption required for thermal management of the battery pack.

[0095] The support plate 31 can switch between a high state and a low state, so that the heat exchange efficiency and the power consumption of thermal management can be flexibly adjusted to meet different practical needs. When the heat exchange demand of the battery pack is low, the support plate 31 is adjusted to a low state to reduce the power consumption of thermal management, thereby reducing the overall energy consumption of the battery pack. When the heat exchange demand of the battery pack is high, the support plate 31 is adjusted to a high state to increase the flow range of the heat exchange medium to meet the actual heat exchange demand.

[0096] The embodiment of the present application provides an energy storage box, which includes an inverter, a battery management system and at least one battery pack, wherein the battery pack is the battery pack in any of the above embodiments. The energy storage box can be provided with a circulation drive device for driving the flow of the heat exchange medium, and the circulation drive device is connected to the liquid inlet 12 and the liquid outlet 13.

[0097] like Figure 9 As shown, an embodiment of the present application provides a temperature control method, the temperature control method comprising:

[0098] S01: Detect the temperature of each measuring point to obtain the temperature of the measuring point;

[0099] S02: Calculate the average temperature of the battery pack based on the temperatures at multiple measurement points within the battery pack;

[0100] S03: Calculate the difference between the measurement point temperature and the average temperature based on the average temperature to obtain the temperature difference;

[0101] S04: Calculate the maximum temperature difference based on the highest temperature and the lowest temperature among the temperatures at each measurement point;

[0102] S05: Adjust the position state of the support plate 31 of the battery pack according to the maximum temperature difference and the temperature difference.

[0103] The temperature control method provided by the embodiments of the present application is used to control the temperature of the energy storage system, such as an energy storage box. The energy storage box includes multiple battery packs, each battery pack includes multiple battery cells 2, measurement points are arranged on the surface of the battery cells, and temperature sensors are arranged at the measurement points on the surface of the battery cells 2 for detecting the temperature conditions of the battery cells 2. Specifically, one temperature sensor should be arranged for every 3 to 5 battery cells 2, and the temperature sensors should be arranged relatively evenly and consistently. The temperature sensor can be an NCT temperature sensor. The temperature Tn at the measurement point within the battery pack can be obtained through the temperature sensor, where Tn refers to the temperature obtained by a certain temperature sensor, and the temperature values obtained by multiple temperature sensors are T1, T2, T3, etc. respectively. Based on the measurement point temperatures Tn obtained by multiple temperature sensors, the average temperature Tavg of a certain battery pack can be calculated, and the calculation formula is: (T1 + T2 +... + Tn) / n = Tavg. Among them, n is a positive integer greater than 0, which refers to the number of measurement points in the formula, and (T1 + T2 +... + Tn) refers to the sum of the temperatures at all measurement points within a corresponding battery pack. The temperature difference refers to the difference between a certain measurement point temperature Tn and the average temperature Tavg, that is, Tn - Tavg, and each measurement point has a temperature difference. The highest temperature Tnmax refers to the maximum value among the temperatures Tn at all measurement points in a certain battery pack, and the lowest temperature Tnmin refers to the minimum value among the temperatures Tn at all measurement points in a certain battery pack. The maximum temperature difference is the difference between the highest temperature Tnmax and the lowest temperature Tnmin, that is, Tnmax - Tnmin. The embodiments of the present application take the adjustment of one battery pack as an example for illustration. The above-mentioned measurement point temperature, temperature difference, average temperature, and maximum temperature difference are all data obtained within the same battery pack. The energy storage system includes multiple battery packs, and the energy storage system can control and adjust each of the multiple battery packs separately.

[0104] Based on the obtained maximum temperature difference and temperature difference value, the current temperature condition of the battery pack can be judged, and then the position state of the support plate 31 of the battery pack can be adjusted according to the maximum temperature difference and temperature difference value, further adjusting the heat dissipation efficiency and heat dissipation power consumption of the battery pack. The energy storage system is provided with a monitoring device that can monitor the current position state of the support plate 31 of each battery pack. Specifically, when it is judged that the battery pack requires stronger heat dissipation efficiency, the position of the support plate 31 is adjusted to the high position state to enhance the heat dissipation capacity of the battery pack. When it is judged that the battery pack only needs a smaller heat dissipation power to meet the requirements, the position state of the support plate 31 is adjusted to the low position state to reduce the power consumption required for the heat dissipation of the battery pack. The method provided by the embodiment of the present application can accurately and reasonably detect and evaluate the temperature state of each battery pack to judge the state that the support plate 31 needs to be set, so as to achieve a balance between the heat dissipation efficiency and the heat dissipation power consumption, which is beneficial to controlling the power consumption of the heat dissipation system.

[0105] In a possible implementation manner, S05: Adjust the position state of the support plate 31 in the battery pack according to the maximum temperature difference and temperature difference value, including:

[0106] S051: When there is a temperature difference greater than or equal to the first temperature threshold, adjust the support plate 31 of the corresponding battery pack to the high position state;

[0107] S052: When all temperature differences are less than the first temperature threshold and the maximum temperature difference is greater than or equal to the second temperature threshold, adjust the support plate 31 of the corresponding battery pack to the high position state;

[0108] S053: When all temperature differences are less than the first temperature threshold and the maximum temperature difference is less than the second temperature threshold, adjust the support plate 31 of the corresponding battery pack to the low position state.

[0109] The first temperature threshold Ta and the second temperature threshold Tb are temperature values preset by the energy storage system according to actual requirements and the specifications of the energy storage system. By reasonably setting the first temperature threshold and the second temperature threshold, reasonable control of the position state of the support plate 31 can be achieved. When Tn - Tavg ≥ Ta, it means that the difference between the measured point temperature Tn and the average temperature Tavg in the corresponding battery pack exceeds the first temperature threshold Ta, and then the support plate of the battery pack is adjusted to the high position state. When Tn - Tavg < Ta and Tnmax - Tnmin ≥ Tb, it means that the differences between the measured point temperature Tn and the average temperature Tavg are all less than the first temperature threshold Ta, and the maximum temperature difference exceeds the second temperature threshold Tb. Then, further judge the required setting position state of the support plate according to the relationship between the maximum temperature difference and the second temperature threshold Tb. The temperature control method provided by this embodiment can accurately judge the current temperature state of the battery pack and the required heat dissipation power, and can accurately adjust the heat dissipation power of the battery pack.

[0110] In a possible implementation manner, after adjusting the position state of the support plate 31 of the battery pack according to the maximum temperature difference and the temperature difference value, the method further includes:

[0111] S06: Detect the number of battery packs in the high position state and the low position state of the support plate;

[0112] S07: When the number of battery packs in the high position state is greater than the number of battery packs in the low position state, increase the refrigeration power of the liquid chiller;

[0113] S08: When the number of battery packs in the high position state is less than or equal to the number of battery packs in the low position state and there are battery packs in the high position state, the refrigeration power of the liquid chiller remains unchanged;

[0114] S09: When all battery packs are in the low position state, reduce the refrigeration power of the liquid chiller.

[0115] A liquid cooling unit is provided in the energy storage system. The liquid cooling unit is used for heat exchange of the heat exchange medium in the liquid cooling circulation loop, such as refrigerating the coolant. The liquid cooling unit is controlled by the battery management system. The power of the liquid cooling unit can be adjusted and has at least three different refrigeration power levels to meet the adjustment of the power of the liquid cooling unit. For example, it includes a first level, a second level and a third level in ascending order of power. The range of the liquid cooling power and the number of levels can be reasonably set according to the working environment and specifications of the cooling system, so that the energy storage system can be adjusted flexibly. By reasonably adjusting the power of the liquid cooling unit, the cooling needs of the battery pack can be met in time, the energy storage system can be kept within a suitable working temperature range, and the overall cooling power consumption of the energy storage system can also be reduced.

[0116] The structure, features and effects of the present application are described in detail based on the embodiments shown in the drawings above. The above is only the preferred embodiment of the present application, but the present application is not limited to the implementation scope shown in the drawings. Any changes made according to the concept of the present application, or modified into equivalent embodiments with equivalent changes, still within the spirit covered by the description and drawings, should be within the protection scope of the present application.

Claims

1. A battery pack, characterized in that, The battery pack includes: Cells, and the battery pack includes a plurality of the cells; A box body having an accommodation cavity, the box body being provided with a liquid inlet and a liquid outlet, and a heat exchange medium being provided in the accommodation cavity; A support assembly provided in the accommodation cavity, the support assembly including a support plate and a support member, the support plate being capable of abutting against the support member, the support plate being capable of dividing the accommodation cavity in the height direction of the box body into a first cavity and a second cavity, the first cavity being located above the second cavity, the cells being provided on the support plate and located in the first cavity, and the first cavity and the second cavity both being provided with a liquid inlet and a liquid outlet; A lifting assembly connected to the support plate, the lifting assembly being configured to drive the support plate to move in the height direction of the battery pack and switch between a low position state and a high position state; When the support plate is in the low position state, the support plate abuts against the support member, the first cavity and the second cavity are relatively closed, the liquid inlet and the liquid outlet communicated with the second cavity are in a closed state, and the liquid inlet and the liquid outlet communicated with the first cavity are in an open state; When the support plate is in the high position state, there is a gap between the support plate and the support member, the first cavity and the second cavity communicate with each other, and all the liquid inlets and liquid outlets are in an open state.

2. The battery pack according to claim 1, characterized in that, The support plate has a plurality of heat dissipation holes, the heat dissipation holes being correspondingly arranged with the cells, and a part of the projection of the cells in the height direction of the battery pack coincides with the projection of the heat dissipation holes.

3. The battery pack according to claim 2, wherein The cross-sectional area of the heat dissipation holes gradually decreases in the direction close to the cells.

4. The battery pack according to claim 1, characterized in that, The support plate has pressure equalizing holes, and the projection of the pressure equalizing holes in the height direction of the battery pack does not coincide with the support member.

5. The battery pack according to claim 1, characterized in that, The projection area of the support plate in the height direction of the battery pack is smaller than the projection area of the bottom wall of the box body, and the projection of the support assembly in the height direction of the battery pack coincides with the projection of the bottom wall of the box body.

6. The battery pack according to claim 1, characterized in that, The lifting assembly includes a driving member and a lifting member, the driving member being capable of driving the lifting member to move in the height direction of the battery pack, and the lifting member being connected to the support plate.

7. The battery pack according to any one of claims 1 to 6, characterized in that, The battery pack includes a partition plate, the partition plate being installed on the support plate and located in the first cavity, one end of the partition plate being connected to the side wall of the box body, and there being a gap between the other end of the partition plate and the side wall of the box body, and the liquid inlet and the liquid outlet being respectively located on both sides of the partition plate.

8. A temperature control method, characterized in that, The temperature control method includes: Detecting the temperature of each measurement point to obtain the measurement point temperature; Calculating the average temperature of the battery pack according to the temperatures of a plurality of the measurement points in the battery pack; Calculating the difference between the temperature of each measurement point and the average temperature according to the average temperature to obtain the temperature difference of each measurement point; Calculating the maximum temperature difference according to the highest temperature and the lowest temperature among the temperatures of each measurement point; Adjusting the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference. Wherein, the battery pack includes a box body and a support assembly. The box body has a receiving cavity, the support assembly is disposed in the receiving cavity, there is a heat exchange medium in the receiving cavity, the support assembly includes the support plate and a support member, the support plate can abut against the support member, the support plate can divide the receiving cavity into a first cavity and a second cavity along the height direction of the box body, and the support plate can move along the height direction of the battery pack; The battery pack is the battery pack according to any one of claims 1 to 7.

9. The temperature control method according to claim 8, characterized in that, Adjusting the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference value includes: When there is a temperature difference value greater than or equal to a first temperature threshold, adjusting the support plate of the corresponding battery pack to a high position state; When all the temperature difference values are less than the first temperature threshold and the maximum temperature difference is greater than or equal to a second temperature threshold, adjusting the support plate of the corresponding battery pack to a high position state; When all the temperature difference values are less than the first temperature threshold and the maximum temperature difference is less than the second temperature threshold, adjusting the support plate of the corresponding battery pack to a low position state.

10. The temperature control method according to claim 8, wherein After adjusting the position state of the support plate of the battery pack according to the maximum temperature difference and the temperature difference value, the method further includes: Detecting the number of battery packs with the support plate in the high position state and the low position state respectively; When the number of battery packs in the high position state is greater than the number of battery packs in the low position state, increasing the refrigeration power of the liquid chiller; When the number of battery packs in the high position state is less than or equal to the number of battery packs in the low position state and there is a battery pack in the high position state, maintaining the refrigeration power of the liquid chiller unchanged; When all the battery packs are in the low position state, reducing the refrigeration power of the liquid chiller.

Images