A lithium ion battery heat dissipation device

Abstract

The application discloses a lithium ion battery heat dissipation device. The refrigerant in the plurality of heat dissipation fins of the heat dissipation device has the same evaporation temperature, the cooling temperature of each square battery is the same, the problem that the cooling temperature of each square battery is different with the increase of the cooling water temperature is avoided in the serpentine cooling pipe scheme, and the consistency of the temperature among different square batteries is improved. The cooling power of the heat dissipation device can be self-adaptive to the heat generation power of the square battery, the surface temperature of the square battery with high heat generation power is increased, the steam production in the heat dissipation fin connected with the square battery is increased, more heat is taken away, and the temperature of the square battery is quickly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion battery energy storage, and in particular to a lithium ion battery heat dissipation device. BACKGROUND

[0002] As a major new energy storage technology, the installed capacity of lithium ion battery energy storage has been rapidly increasing in recent years. In order to improve the cycle performance and number of lithium ion batteries and avoid problems such as thermal runaway of lithium ion batteries that affect the safety of energy storage systems, it is necessary to ensure that the lithium ion batteries are always in a reasonable temperature range during use. For lithium iron phosphate batteries, the working temperature should be between 25-45℃. Therefore, lithium ion battery energy storage systems need to be equipped with thermal management devices. The current main lithium ion battery thermal management schemes mainly include air cooling and liquid cooling schemes. The main problems of the air cooling scheme are large temperature deviation between different batteries and high energy consumption. The liquid cooling scheme can reduce the temperature difference between different batteries and reduce energy consumption.

[0003] The current liquid cooling scheme generally uses a liquid cooling bottom plate, and the lithium ion battery is placed above the liquid cooling bottom plate. The heat is transferred from top to bottom to the liquid cooling bottom plate, which has problems such as long vertical heat transfer path, low heat transfer coefficient, and large temperature gradient. In addition, since the liquid cooling plate usually uses a serpentine microchannel, the flow resistance of the cooling medium is large. SUMMARY

[0004] The present application aims to at least partially solve one of the problems in the related art.

[0005] To this end, an embodiment of the present application proposes a lithium ion battery heat dissipation device.

[0006] The present application proposes a lithium ion battery heat dissipation device, comprising:

[0007] A U-shaped cooling water pipe, the U-shaped cooling water pipe comprises an upper pipe arm and a lower pipe arm below the upper pipe arm, an upper sleeve is sleeved outside the upper pipe arm, both ends of the upper sleeve are sealingly connected with the outer wall of the upper pipe arm, a lower sleeve is sleeved outside the lower pipe arm, both ends of the lower sleeve are sealingly connected with the outer wall of the lower pipe arm, and the upper sleeve and the lower sleeve are communicated through a plurality of descending pipes;

[0008] A plurality of hollow structure heat dissipation fins, both heat dissipation surfaces of the heat dissipation fins are tightly attached to the maximum heat generating surface of the battery, the upper part of the heat dissipation fin is communicated with the upper sleeve through an upper connecting pipe, the lower part of the heat dissipation fin is communicated with the lower sleeve through a lower connecting pipe, and the heat dissipation fin, the upper connecting pipe, the lower connecting pipe, the upper sleeve, the lower sleeve and the descending pipe form a communication space.

[0009] In some embodiments, when the heat-emitting surface of the battery increases in temperature, the refrigerant in the heat sink is heated to generate steam, the steam enters the annular space between the upper sleeve and the U-shaped cooling water pipe through the upper connecting pipe, condenses into condensed liquid on the outer surface of the upper side pipe arm of the U-shaped cooling water pipe, and then enters the heat sink through the descending pipe and the lower connecting pipe.

[0010] In some embodiments, the low-temperature cooling water flows into the upper side pipe arm, exchanges heat with the steam, and then flows out of the lower side pipe arm.

[0011] In some embodiments, the lower connecting pipe is located at any position of the lower side pipe arm in the vertical direction, and the upper connecting pipe is located at any position of the upper side pipe arm in the vertical direction.

[0012] In some embodiments, the injection amount of the refrigerant is 20%-90% of the internal space of the heat sink.

[0013] In some embodiments, several heat sinks are symmetrically arranged in parallel on the left and right sides of the U-shaped cooling water pipe.

[0014] In some embodiments, several parallel heat sinks have the same evaporation pressure.

[0015] In some embodiments, the outer wall of the upper side pipe arm and the upper sleeve, and the outer wall of the lower side pipe arm and the lower sleeve are sealingly connected by tapered pipes.

[0016] In some embodiments, a heat-conducting adhesive is arranged between the heat-emitting surface of the heat sink and the heat-emitting surface of the battery.

[0017] In some embodiments, the heat-conducting adhesive is one of silicone heat-conducting adhesive, polyurethane adhesive, or heat-conducting silicone adhesive.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] The refrigerant in the multiple heat sinks of the present application has the same evaporation temperature, and the cooling temperature of each square battery is the same, which avoids the problem that the cooling temperature of each square battery is different as the cooling water temperature increases in the serpentine cooling pipe scheme, and improves the consistency of the temperature between different square batteries.

[0020] The cooling power of the heat dissipation device of the present application can be self-adaptive to the heat-emitting power of the square battery, and the surface temperature of the square battery with high heat-emitting power increases, so that the steam production in the heat sink connected thereto increases, and more heat is taken away, thereby reducing the temperature of the square battery.

[0021] The square battery of the present application is in phase change heat transfer with the refrigerant and the refrigerant is in phase change heat transfer with the U-shaped cooling water pipe, so that the heat transfer system is high and the cooling effect can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A schematic view of the heat dissipation device combined with the battery cell;

[0024] Figure 2 A schematic view of the structure of the heat dissipation device;

[0025] Figure 3 A schematic view of the connection structure between the U-shaped cooling water pipe, the sleeve pipe and the down pipe;

[0026] Figure 4 A schematic view after the refrigerant is injected into the heat dissipation fin;

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 1, square battery; 2, heat dissipation fin; 3, U-shaped cooling water pipe; 4, upper sleeve pipe; 5, lower sleeve pipe; 6, down pipe; 7, upper connecting pipe; 8, lower connecting pipe; 9, upper side pipe arm; 10, lower side pipe arm. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0030] The lithium ion battery heat dissipation device according to the embodiments of the present application will be described below with reference to the accompanying drawings.

[0031] As shown in the drawings, Figures 1-4 The lithium ion battery heat dissipation device of the present application includes a U-shaped cooling water pipe 3, a heat dissipation fin 2, a down pipe 6, an upper sleeve pipe 4, a lower sleeve pipe 5, an upper connecting pipe 7 and a lower connecting pipe 8.

[0032] The U-shaped cooling water pipe 3 includes an upper side pipe arm 9 and a lower side pipe arm 10, the upper side pipe arm 9 is located above the lower side pipe arm 10, and the upper side pipe arm 9 and the lower side pipe arm 10 are communicated so that the cooling water can flow from the upper side pipe arm 9 and then flow out from the lower side pipe arm 10.

[0033] The cooling water is used to exchange heat with steam generated by the refrigerant to condense the steam into condensed liquid. The cooling water is low-temperature cooling water, and the temperature of the low-temperature cooling water is lower than 20℃. It can be understood that the appropriate cooling water temperature is selected according to different working conditions.

[0034] In the heat dissipation device, the low-temperature cooling water only flows in the U-shaped cooling water pipe 3, the pipe diameter of the U-shaped cooling water pipe 3 is large, the length is short, and the flow resistance is small, so that the energy consumption of the cooling water system can be reduced by more than 40%.

[0035] The upper sleeve pipe 4 is sealingly connected to the outer wall of the upper pipe arm 9. Specifically, the upper sleeve pipe 4 is sleeved on the outer wall of the upper pipe arm 9, the length of the upper sleeve pipe 4 is less than the length of the upper pipe arm 9, and the two ends of the upper sleeve pipe 4 are sealingly connected to the outer wall of the upper pipe arm 9, so as to form an annular space between the upper sleeve pipe 4 and the outer wall of the upper pipe arm 9. In some embodiments, the outer wall of the upper pipe arm 9 and the upper sleeve pipe 4 are sealingly connected by a tapered pipe. The cross-sectional area of the tapered pipe gradually decreases from small to large. The end of the tapered pipe with a large cross-sectional area is connected to the upper sleeve pipe 4, and the end of the tapered pipe with a small cross-sectional area is connected to the upper pipe arm 9. Thus, the two ends of the upper sleeve pipe 4 and the outer wall of the upper pipe arm 9 are sealingly connected by the tapered pipe to form a chamber with both ends sealed.

[0036] The lower sleeve pipe 5 is sealingly connected to the outer wall of the lower pipe arm 10. Specifically, the lower sleeve pipe 5 is sleeved on the outer wall of the lower pipe arm 10, the length of the lower sleeve pipe 5 is less than the length of the lower pipe arm 10, and the two ends of the lower sleeve pipe 5 are sealingly connected to the outer wall of the lower pipe arm 10, so as to form an annular space between the lower sleeve pipe 5 and the outer wall of the lower pipe arm 10. In some embodiments, the outer wall of the lower pipe arm 10 and the lower sleeve pipe 5 are sealingly connected by a tapered pipe. The cross-sectional area of the tapered pipe gradually decreases from small to large. The end of the tapered pipe with a large cross-sectional area is connected to the lower sleeve pipe 5, and the end of the tapered pipe with a small cross-sectional area is connected to the lower pipe arm 10. Thus, the two ends of the lower sleeve pipe 5 and the outer wall of the lower pipe arm 10 are sealingly connected by the tapered pipe to form a chamber with both ends sealed.

[0037] The upper sleeve pipe 4 and the lower sleeve pipe 5 are connected by the downpipe 6. The downpipe 6 is arranged between the upper sleeve pipe 4 and the lower sleeve pipe 5, so as to connect the upper sleeve pipe 4 located above and the lower sleeve pipe 5 located below, and enable the condensed liquid formed on the outer wall of the upper pipe arm 9 to enter the lower sleeve pipe 5 through the downpipe 6. A plurality of downpipes 6 can be arranged between the upper sleeve pipe 4 and the lower sleeve pipe 5. It can be understood that arranging a plurality of downpipes 6 can increase the flow of condensed liquid, thereby further improving the heat dissipation efficiency. Preferably, the downpipe 6 is vertically arranged between the upper sleeve pipe 4 located above and the lower sleeve pipe 5 located below.

[0038] The fin 2 is a hollow structure, the fin 2 of the hollow structure is vacuumized, and a refrigerant is injected into the internal space of the fin 2, the refrigerant is evaporated by heat to absorb heat generated by the battery during charging and discharging, thereby reducing the temperature of the battery, so that the lithium ion battery is in a suitable temperature range, and problems such as thermal runaway of the lithium ion battery affecting the safety of the energy storage system are avoided. Preferably, the injection amount of the refrigerant is 20%-90% of the internal space of the fin 2. In addition, the refrigerant is non-flammable and non-conductive, and even if it leaks, it will not cause a short circuit of the battery, so the heat dissipation device of the present application is safe.

[0039] Taking the square battery 1 as an example, the maximum surface of the square battery 1 is used as the maximum heat generating surface of the square battery 1, each fin 2 has two heat dissipation surfaces, and the maximum heat generating surface of the square battery 1 is tightly attached to the heat dissipation surface of the fin 2, thereby improving the heat dissipation efficiency. As shown in Figure 1 two square batteries 1, except for the outermost fin 2, the two heat dissipation surfaces of each fin 2 are in close contact with the maximum heat generating surface of one square battery 1.

[0040] In some embodiments, a heat-conducting adhesive is provided between the heat dissipation surface of the fin 2 and the heat generating surface of the square battery 1. It can be understood that the heat transfer efficiency and the heat dissipation efficiency can be improved by providing a heat-conducting adhesive between the heat dissipation surface of the fin 2 and the heat generating surface of the square battery 1. The heat-conducting adhesive is one of silicone heat-conducting adhesive, polyurethane adhesive or heat-conducting silicone adhesive. It can be understood that the heat-conducting adhesive can also be other suitable materials.

[0041] The upper part of the fin 2 is connected to the upper sleeve 4 through the upper connecting pipe 7, and the lower part of the fin 2 is connected to the lower sleeve 5 through the lower connecting pipe 8. Specifically, the upper part of the fin 2 is provided with a connecting hole for connecting the upper connecting pipe 7, and the outer wall of the upper sleeve 4 is also provided with a connecting hole for connecting the upper connecting pipe 7, that is, one end of the upper connecting pipe 7 is connected to the upper part of the fin 2, and the other end of the upper connecting pipe 7 is connected to the upper sleeve 4, so that the fin 2 and the upper sleeve 4 are connected through the upper connecting pipe 7; the lower part of the fin 2 is provided with a connecting hole for connecting the lower connecting pipe 8, and the outer wall of the lower sleeve 5 is also provided with a connecting hole for connecting the lower connecting pipe 8, that is, one end of the lower connecting pipe 8 is connected to the lower part of the fin 2, and the other end of the lower connecting pipe 8 is connected to the lower sleeve 5, so that the fin 2 and the lower sleeve 5 are connected through the lower connecting pipe 8, and the upper sleeve 4 and the lower sleeve 5 are connected through the descending pipe 6, and thus the fin 2, the upper connecting pipe 7, the lower connecting pipe 8, the upper sleeve 4, the lower sleeve 5 and the descending pipe 6 form a connected space.

[0042] The lower connecting pipe 8 is located at any position on the lower tube arm 10 in the vertical direction, and the upper connecting pipe 7 is located at any position on the upper tube arm 9 in the vertical direction. Specifically, one end of the upper connecting pipe 7 is connected to the upper sleeve 4, which is fitted outside the upper tube arm 9. The function of the upper connecting pipe 7 is to allow steam to enter the annular space between the upper sleeve 4 and the upper tube arm 9. Therefore, there is no need to specify the vertical position relationship between the upper connecting pipe 7 and the upper tube arm 9. One end of the lower connecting pipe 8 is connected to the lower sleeve 5, which is fitted outside the lower tube arm 10. The function of the lower connecting pipe 8 is to allow condensate to enter the lower connecting pipe 8 through the downcomer 6 from the annular space between the lower sleeve 5 and the lower tube arm 10, and finally enter the heat sink 2. Therefore, there is no need to specify the vertical position relationship between the lower connecting pipe 8 and the lower tube arm 10.

[0043] Several heat sinks 2 are symmetrically arranged in parallel on the left and right sides of the U-shaped cooling water pipe 3, and the multiple heat sinks 2 arranged in parallel on the left and right sides of the U-shaped cooling water pipe 3 are interconnected.

[0044] During operation, the internal space of the heat dissipation device is evacuated and then refrigerant is injected. It is understandable that a suitable refrigerant is selected based on the operating conditions. For example... Figure 4 As shown in the dashed line, after the refrigerant is injected, based on the principle of communicating vessels, the liquid level of the refrigerant in the heat sink 2 is the same as the liquid level of the refrigerant in the downcomer 6.

[0045] When the temperature of the heating surface of the square battery 1 rises, the refrigerant in the heat sink 2 is heated and generates steam. The steam enters the annular space between the upper sleeve 4 and the U-shaped cooling water pipe 3 through the upper connecting pipe 7. It condenses into condensate on the outer surface of the upper tube arm 9 of the U-shaped cooling water pipe 3. The condensate enters the lower sleeve 5 through the downcomer pipe 6 and then enters the heat sink 2 through the lower connecting pipe 8.

[0046] Specifically, in the charging and discharging process, the heat-emitting surface temperature of the square battery 1 rises, the maximum heat-emitting surface of the square battery 1 contacts the heat-emitting surface of the fin 2, thereby conducting heat to the fin 2, the refrigerant in the fin 2 is heated to evaporate and generate steam, the refrigerant absorbs heat to thereby take out the heat generated by the square battery 1; the steam generated by the heated refrigerant enters the annular space between the upper sleeve 4 and the U-shaped cooling water pipe 3 through the upper connecting pipe 7 at the upper part of the fin 2, the low-temperature cooling water flows in from the upper side pipe arm 9 of the U-shaped cooling water pipe 3, so that the steam exchanges heat with the low-temperature cooling water, and the steam condenses into condensed liquid on the outer surface of the upper side pipe arm 9; the condensed liquid enters the descending pipe 6, so that the liquid level of the refrigerant in the descending pipe 6 rises, and based on the principle of communicating vessels, the liquid level of the refrigerant in the descending pipe 6 tends to be the same as the liquid level of the refrigerant in the fin 2, therefore, after the condensed liquid enters the descending pipe 6, the liquid level of the refrigerant in the descending pipe 6 first rises and then falls, so that the condensed liquid enters the lower sleeve 5 located at the lower part of the fin 2 through the descending pipe 6, and finally enters the fin 2 through the lower connecting pipe 8.

[0047] The multiple fins 2 in parallel have the same evaporation pressure, and therefore the same evaporation temperature, so that the cooling temperature of each square battery 1 is the same, avoiding the problem that the cooling temperature of each square battery 1 is different in the serpentine cooling pipe scheme as the cooling water temperature rises, and improving the consistency of the temperature among different square batteries 1, so that the temperature difference among the square batteries 1 is small, even lower than 1℃.

[0048] The cooling power of the heat dissipation device can be self-adaptive to the heat-emitting power of the square battery 1, and in the working process, if the temperature of a certain square battery 1 is higher than that of other square batteries 1, the steam production in the fin 2 adjacent to the square battery 1 will increase, thereby taking out more heat and rapidly reducing the temperature of the square battery 1.

[0049] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms can be directed to different embodiments or examples. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0050] Furthermore, the terms "first", "second", "third", etc. as used herein are used as labels, and do not necessarily indicate any real-world precedence or relation among terms so denominated. However, matrices of the same type can be implicitly or explicitly included, where a feature labeled with "first", "second", etc. is mentioned. In the description of the application, the meaning of "a plurality" is at least two, such as two, three, etc., unless explicitly specified otherwise.

[0051] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. A heat dissipation device for a lithium ion battery, characterized by, The application relates to a battery cooling device. The U-shaped cooling water pipe comprises an upper pipe arm and a lower pipe arm below the upper pipe arm, an upper sleeve is sleeved outside the upper pipe arm, two ends of the upper sleeve are sealingly connected with the outer wall of the upper pipe arm, a lower sleeve is sleeved outside the lower pipe arm, two ends of the lower sleeve are sealingly connected with the outer wall of the lower pipe arm, and the upper sleeve and the lower sleeve are communicated through a plurality of descending pipes; A plurality of hollow-structure radiating fins are arranged between two adjacent square batteries, two radiating surfaces of each radiating fin are in close contact with the maximum heat generating surfaces of the square batteries, the upper parts of the radiating fins are communicated with the upper sleeve through upper connecting pipes, the lower parts of the radiating fins are communicated with the lower sleeve through lower connecting pipes, the radiating fins, the upper connecting pipes, the lower connecting pipes, the upper sleeve, the lower sleeve and the descending pipes form a communicating space, When the heat generating surface temperature of the battery rises, the refrigerant in the radiating fin is heated to generate steam, the steam enters the annular space between the upper sleeve and the U-shaped cooling water pipe through the upper connecting pipe, is condensed into condensed liquid on the outer surface of the upper pipe arm of the U-shaped cooling water pipe, enters the lower sleeve through the descending pipe and then enters the radiating fin through the lower connecting pipe, low-temperature cooling water flows into the upper pipe arm, exchanges heat with the steam and then flows out of the lower pipe arm, a plurality of parallel radiating fins have the same evaporation pressure, and a plurality of parallel radiating fins are symmetrically arranged on the left and right sides of the U-shaped cooling water pipe.

2. The apparatus of claim 1, wherein, The lower connecting pipe is located at any position of the lower pipe arm in the vertical direction, and the upper connecting pipe is located at any position of the upper pipe arm in the vertical direction.

3. The apparatus of claim 2, wherein, The injection amount of the refrigerant is 20%-90% of the internal space of the radiating fin.

4. The apparatus of claim 1, wherein, The outer wall of the upper pipe arm and the upper sleeve and the outer wall of the lower pipe arm and the lower sleeve are sealingly connected through taper pipes.

5. The apparatus of claim 1, wherein, Thermal conductive glue is arranged between the radiating surface of the radiating fin and the heat generating surface of the battery.

6. The apparatus of claim 5, wherein, The thermal conductive glue is one of silicone thermal conductive glue, polyurethane glue or thermal conductive silica gel.

Images