Double-layer liquid cooling system and battery pack

Abstract

The application discloses a double-layer liquid cooling system, which comprises a first layer of liquid cooling plates; a second layer of liquid cooling plates arranged above the first layer of liquid cooling plates; at least two inlets arranged on the second layer of liquid cooling plates, cooling liquid in the first layer of liquid cooling plates being transported to the second layer of liquid cooling plates from the inlets; an outlet arranged on the second layer of liquid cooling plates, the number of the outlet being at least one but less than that of the inlets, cooling liquid in the second layer of liquid cooling plates being transported to the first layer of liquid cooling plates from the outlet; the cooling liquid flows from the first layer of liquid cooling plates to the second layer of liquid cooling plates and then flows back to the first layer of liquid cooling plates from the second layer of liquid cooling plates; and the second layer of battery modules is the farthest end module (farthest from the cooling liquid inlet of the first layer of liquid cooling plates), the number of the inlets arranged on the second layer of liquid cooling plates is increased, the flow of the cooling liquid into the second layer of liquid cooling plates is increased, heat exchange of the second layer of liquid cooling plates and the second layer of battery modules is improved, and the temperature difference of the whole package is reduced.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more particularly to a dual-layer liquid cooling system and battery pack. Background Technology

[0002] With the development of battery technology, battery packs are becoming increasingly integrated. As the integration of battery packs increases, their internal space becomes more compact, requiring extreme space compression to meet design requirements. Due to the limitations of the length and width of the battery pack, a dual-layer battery module design has emerged to meet the power requirements of the product itself. The stamped liquid cooling plate used for cooling the dual-layer battery module is divided into a flat plate layer and a stamped flow channel layer. The coolant flows from the flat plate layer to the stamped flow channel layer through a quick-connect pipe, and then the stamped flow channel layer returns the coolant to the flat plate layer through another quick-connect pipe.

[0003] Therefore, since the stamped flow channel layer is the cooling layer furthest from the coolant inlet of the flat plate layer, the coolant is affected by gravity, pressure loss, etc., resulting in low coolant flow rate and low flow velocity in this layer. Consequently, the temperature of the battery module above the stamped flow channel layer is the most difficult to control, which can easily lead to the problem of difficulty in ensuring temperature uniformity in the double-layer design. Summary of the Invention

[0004] To overcome at least one of the defects described in the prior art, the present invention provides a dual-layer liquid cooling system and a battery pack. The system has multiple channels from the first cooling plate to the second cooling plate, and the second cooling plate has at least one channel from the first cooling plate to the first cooling plate, but fewer than the number of channels from the first cooling plate to the second cooling plate. This increases the amount of coolant flowing from the first cooling plate to the second cooling plate, improves the heat exchange between the two liquid cooling plates and the battery module, and reduces the overall temperature difference of the battery pack.

[0005] The technical solution adopted by this invention to solve its problem is:

[0006] A dual-layer liquid cooling system includes a first layer of liquid cooling plate;

[0007] The second liquid cooling plate is disposed above the first liquid cooling plate. The second liquid cooling plate has at least two inlets. The coolant in the first liquid cooling plate is transported to the second liquid cooling plate through the inlets. The second liquid cooling plate has an outlet, the number of which is at least one but less than the number of inlets. The coolant in the second liquid cooling plate flows back to the first liquid cooling plate through the outlet.

[0008] Furthermore, it also includes an inlet pipe and a return pipe. One end of the inlet pipe is connected to the first liquid cooling plate and the other end is connected to the inlet. One end of the return pipe is connected to the first liquid cooling plate and the other end is connected to the outlet.

[0009] Furthermore, both the inlet pipe and the return pipe have an L-shaped structure.

[0010] Furthermore, one end of the liquid inlet pipe is provided with a nozzle, and the liquid inlet pipe is connected to the side of the second liquid cooling plate near the first liquid cooling plate through the nozzle;

[0011] And / or one end of the return pipe is provided with a nozzle, and the return pipe is connected to the side of the second liquid cooling plate near the first liquid cooling plate through the nozzle.

[0012] Furthermore, the second liquid cooling plate is provided with flow channels that correspond one-to-one with the inlet, and the other end of the flow channel away from the inlet is connected to the outlet, and multiple flow channels are arranged in parallel.

[0013] Furthermore, the flow channel has a bent structure.

[0014] Furthermore, each of the flow channels includes two branches, which are connected in parallel.

[0015] Furthermore, the number of imports is two, and the number of exports is one.

[0016] Furthermore, the first liquid cooling plate is provided with an inlet pipe and an outlet pipe.

[0017] A battery pack includes the dual-layer liquid cooling system and two battery modules, one battery module being disposed between the first liquid cooling plate and the second liquid cooling plate, and the other battery module being disposed above the second liquid cooling plate.

[0018] In summary, the dual-layer liquid cooling system and battery pack provided by this invention have the following technical advantages:

[0019] 1) By setting multiple inlets on the second liquid cooling plate, the flow rate of coolant entering the second liquid cooling plate is increased, thereby improving the heat exchange between the second liquid cooling plate and the second battery module.

[0020] 2) In terms of temperature uniformity, the multi-channel parallel design includes two branches. The coolant flows from the first liquid cooling plate to the second liquid cooling plate, and then flows back from the second liquid cooling plate to the first liquid cooling plate. The second battery module is the farthest module (the distance from the coolant inlet of the first liquid cooling plate). The more parallel branches there are, the smaller the flow resistance of the second liquid cooling plate, which is more conducive to the flow of coolant, increases the heat exchange of the second battery module, and reduces the temperature difference of the whole pack.

[0021] 3) In terms of spatial design, the nozzle is connected to the side of the second liquid cooling plate close to the first liquid cooling plate. The inlet pipe and return pipe do not need to extend upward from the side of the second liquid cooling plate and finally connect downward to the side of the second liquid cooling plate away from the first liquid cooling plate. This avoids bending of the inlet pipe and return pipe, which reduces flow resistance and saves space.

[0022] 4) The bending structure of the flow channel increases the travel distance of the coolant in the first liquid cooling plate. The longer the travel distance of the coolant, the more time it has to absorb the heat dissipated by the battery module. Therefore, the more heat the coolant absorbs, the better the cooling effect of the coolant on the battery module. Thus, the longer the travel distance of the flow channel, the better the heat dissipation effect of the flow channel. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0024] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0025] Figure 3 A schematic diagram showing the connection position of the existing nozzle on the second layer of liquid cooling plate;

[0026] Figure 4 This is a schematic diagram of the flow channel of the second liquid cooling plate in Embodiment 2 of the present invention.

[0027] The meanings of the reference numerals in the attached figures are as follows:

[0028] 1. First liquid cooling plate; 2. Second liquid cooling plate; 3. Inlet pipe; 4. Return pipe; 5. Flow channel; 51. First branch; 52. Second branch; 53. Third branch; 54. Fourth branch; 6. Nozzle; 7. Inlet pipe; 8. Outlet pipe. Detailed Implementation

[0029] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0032] Example 1

[0033] See Figure 1 and Figure 2 This invention discloses a double-layer liquid cooling system, comprising:

[0034] The first liquid cooling plate 1 (i.e., the flat plate layer) and the second liquid cooling plate 2 (i.e., the stamped flow channel layer) are disposed above the first liquid cooling plate 1 (i.e., the second liquid cooling plate 2 and the first liquid cooling plate 1 are stacked).

[0035] The second liquid cooling plate 2 has two inlets at both ends on one side, and an outlet is located between the two inlets, with the two inlets and the outlet on the same straight line.

[0036] Each inlet is equipped with a liquid inlet pipe 3, one end of which is connected to the inlet and the other end is connected to the first liquid cooling plate 1; one end of the return pipe 4 is connected to the outlet and the other end is connected to the first liquid cooling plate 1.

[0037] For better information, see [link to relevant documentation]. Figure 2 One end of the liquid inlet pipe 3 and the return pipe 4 is provided with a nozzle 6 (this nozzle 6 is a general CQC (Compact quick connection system) nozzle, that is, a compact quick-connect system, which will not be described in detail here). The liquid inlet pipe 3 and the return pipe 4 are connected to the second liquid cooling plate 2 through the nozzle 6.

[0038] Specifically, the nozzle 6 of one end of the liquid inlet pipe 3 and the return pipe 4 (that is, the top end of the liquid inlet pipe 3 and the return pipe 4) is connected to the side of the second liquid cooling plate 2 near the first liquid cooling plate 1, and the other end is connected to the side of the first liquid cooling plate 1 near the second liquid cooling plate 2.

[0039] As can be seen from the above, see Figure 3 The top of the liquid inlet pipe 3 and the return pipe 4 do not need to extend upward from the side of the second liquid cooling plate 2 and finally downward to the side of the second liquid cooling plate 2 away from the first liquid cooling plate, thus avoiding the bending of the liquid inlet pipe and the return pipe, which reduces flow resistance and saves space.

[0040] Alternatively, nozzles 6 can be installed at the bottom ends of the inlet pipe 3 and the return pipe 4, and both can be connected to the first liquid cooling plate 1 through the nozzles 6.

[0041] The first liquid cooling plate 1 has an inlet pipe 7 and an outlet pipe 8 respectively installed at both ends on the side away from the liquid inlet pipe 3.

[0042] A battery pack includes a dual-layer liquid cooling system and two battery modules, wherein the first battery module is disposed between a first liquid cooling plate 1 and a second liquid cooling plate 2, and the second battery module is disposed above the second liquid cooling plate 2.

[0043] The cooling principle of the battery pack is as follows: the coolant enters the first liquid cooling plate 1 through the inlet pipe 7, and the coolant in the first liquid cooling plate 1 enters the second liquid cooling plate 2 through the two inlet pipes 3. After passing through the second liquid cooling plate 2, the coolant flows back to the first liquid cooling plate 1 through the return pipe 4. Both the first liquid cooling plate 1 and the second liquid cooling plate 2 can absorb and carry away the heat of the first battery module, while the heat of the second battery module is absorbed and carried away by the second liquid cooling plate 2. After the coolant from the second liquid cooling plate 2 flows back to the first liquid cooling plate 1, it is discharged from the first liquid cooling plate 1 through the outlet pipe 8.

[0044] As can be seen from the above, in this embodiment, two inlets and one outlet are provided on the second liquid cooling plate 2. The two inlets increase the amount of coolant entering the second liquid cooling plate 2, thereby improving the heat exchange effect between the second battery module and the second liquid cooling plate 2.

[0045] If the liquid cooling plate needs to be recycled, the inlet pipe 7 and the outlet pipe 8 can be connected, or a coolant transfer station can be set up between the inlet pipe 7 and the outlet pipe 8. The coolant in the outlet pipe 8 flows into the transfer station and then flows into the inlet pipe 7 to continue the next cycle of heat absorption.

[0046] The other two pipes, inlet pipe 3 and return pipe 4, are both L-shaped. Using the same structure for both pipes makes it easier to use the same types of materials, which improves the versatility of materials, saves manufacturing costs, and facilitates the storage and management of materials.

[0047] In other embodiments, the number of imports can be greater than two, and the number of exports can be at least one but less than the number of imports. For example, if the number of imports is three, the number of exports can be one or two.

[0048] Example 2

[0049] Based on Example 1, see [link / reference] Figure 4 The flow trajectory of the coolant on the second liquid cooling plate 2 is as follows: the second liquid cooling plate 2 is provided with flow channels 5.

[0050] In Example 1, there are two inlets, so in this example, there are also two flow channels 5, that is, one flow channel 5 corresponds to one inlet; specifically, one end of one flow channel 5 is connected to one inlet, and the other end is connected to the outlet; one end of another flow channel 5 is connected to another inlet, and the other end is connected to the outlet.

[0051] The significance of one inlet corresponding to one flow channel is that the coolant entering the second liquid cooling plate 2 through each inlet will have a corresponding flow channel 5 for coolant circulation, avoiding the problem of slow coolant flow rate in flow channel 5 due to large coolant volume, that is, the problem of high flow resistance; therefore, after the inlet and flow channel correspond, the coolant flow rate in flow channel 5 is faster and the flow resistance is smaller, which can achieve better heat dissipation effect.

[0052] Specifically, the two flow channels 5 are arranged in parallel, and the flow channel 5 has a bent structure. Specifically, the flow channel 5 is a serpentine structure including multiple 90° bends. This structure helps to increase the path of the coolant in the second cooling plate 2, so as to absorb more heat from the battery module. Specifically, the longer the coolant's path, the more time the coolant has to absorb the heat dissipated by the battery module. Therefore, the more heat the coolant absorbs, the better the cooling effect of the coolant on the battery module. Thus, the longer the flow channel's path, the better the heat dissipation effect of the flow channel. Therefore, the path of the flow channel 5 is as long as possible.

[0053] More preferably, to reduce the flow resistance of the flow channel 5, each flow channel 5 includes two branches, one end of which is connected to the same inlet, and the other end of which is connected to the outlet; it can be seen that the two flow channels 5 correspond to four branches, which are arranged in parallel, and the four branches are the first branch 51, the second branch 52, the third branch 53 and the fourth branch 54 (e.g. Figure 4 As shown), the first branch 51 and the second branch 52 belong to the same flow channel 5, while the third branch 53 and the fourth branch 54 belong to another flow channel 5.

[0054] After the coolant reaches the inlet, it will be diverted into two branches and finally flow into the outlet. The diversion of coolant can effectively increase the flow rate of coolant. Therefore, it can be known that the more branches there are, the smaller the flow resistance. Thus, the number of branches can be selected according to actual needs. Therefore, there can be more than two branches in the same flow channel 5.

[0055] In summary, the coolant flows into the first liquid cooling plate 1 through the inlet pipe, then flows through the inlet pipe 3 to the second liquid cooling plate 2, and then flows back to the first liquid cooling plate 1 through the return pipe 4. The second battery module is the furthest module (farthest from the coolant inlet of the first liquid cooling plate). Due to the influence of gravity, pressure loss, etc., the coolant flow rate of the second liquid cooling plate 2 will be reduced accordingly, and the flow rate will be lower. Therefore, the temperature of the second battery module above the second liquid cooling plate 2 is the most difficult to control.

[0056] In this embodiment, the flow channel 5 includes multiple branches. The more parallel branches on the second liquid cooling plate 2, the smaller the flow resistance of the second liquid cooling plate, which is more conducive to the inflow of coolant, increases the heat exchange of the second battery module, makes the temperature of the second battery module better controlled, thereby reducing the temperature difference of the whole pack, avoiding the problem of excessive local temperature inside the battery pack, and improving the quality of the battery pack.

[0057] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A double-layer liquid cooling system, characterized in that, include First liquid cooling plate (1); The second liquid cooling plate (2) is disposed above the first liquid cooling plate (1). The second liquid cooling plate (2) is provided with at least two inlets. The coolant in the first liquid cooling plate (1) is transported to the second liquid cooling plate (2) through the inlets. The second liquid cooling plate (2) is provided with an outlet. The number of outlets is at least one but less than the number of inlets. The coolant in the second liquid cooling plate (2) flows back to the first liquid cooling plate (1) through the outlet. The first layer of liquid cooling plate (1) is provided with an inlet pipe (7) and an outlet pipe (8).

2. The double-layer liquid cooling system according to claim 1, characterized in that, It also includes an inlet pipe (3) and a return pipe (4). One end of the inlet pipe (3) is connected to the first layer of liquid cooling plate (1), and the other end is connected to the inlet. One end of the return pipe (4) is connected to the first layer of liquid cooling plate (1), and the other end is connected to the outlet.

3. The double-layer liquid cooling system according to claim 2, characterized in that, Both the inlet pipe (3) and the return pipe (4) are L-shaped structures.

4. The double-layer liquid cooling system according to claim 2, characterized in that, One end of the liquid inlet pipe (3) is provided with a nozzle (6), and the liquid inlet pipe (3) is connected to the side of the second layer liquid cooling plate (2) near the first layer liquid cooling plate (1) through the nozzle (6); And / or one end of the return pipe (4) is provided with a nozzle (6), and the return pipe (4) is connected to the side of the second liquid cooling plate (2) near the first liquid cooling plate (1) through the nozzle (6).

5. A double-layer liquid cooling system according to claim 1, characterized in that, The second layer of liquid cooling plate (2) is provided with flow channels (5) that are connected to the inlet one by one. The other end of the flow channel (5) away from the inlet is connected to the outlet. Multiple flow channels (5) are arranged in parallel.

6. A double-layer liquid cooling system according to claim 5, characterized in that, The flow channel (5) has a bent structure.

7. A double-layer liquid cooling system according to claim 5, characterized in that, Each of the flow channels (5) includes two branches, which are connected in parallel.

8. A double-layer liquid cooling system according to claim 4 or 7, characterized in that, The number of imports is two, and the number of exports is one.

9. A battery pack, characterized in that, Includes a dual-layer liquid cooling system as described in any one of claims 1-8 and a two-layer battery module, wherein the first layer of the battery module is disposed between the first layer of liquid cooling plate (1) and the second layer of liquid cooling plate (2), and the second layer of the battery module is disposed above the second layer of liquid cooling plate (2).

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