Immersed battery liquid cooling device and energy storage battery pack

Abstract

The utility model provides an immersed battery liquid cooling device and an energy storage battery pack, and belongs to the field of battery liquid cooling, the immersed battery liquid cooling device comprises a heat exchange tube, the heat exchange tube is arranged in a shell and is positioned at the top of a battery, and the heat exchange tube is immersed below the liquid level of a heat-conducting medium; the infusion tube is arranged in the shell and located at the bottom of the battery, and through holes are distributed in the infusion tube. The circulating pump pumps the heat-conducting medium; a backflow opening is formed in the position, close to the liquid level of the heat-conducting medium, of the side wall of the shell and communicates with the liquid conveying pipe through a circulating pump, and the heat-conducting medium at the bottom of the shell is sucked through the through hole and then conveyed to the top of the shell through the backflow opening through the circulating pump. According to the utility model, the immersion liquid flows through the gaps of the batteries from top to bottom to form the cooling flow channels, the low-temperature immersion liquid continuously exchanges heat with the battery pack heating in the charging and discharging process, the high-temperature immersion liquid carrying heat flows back to the top of the box body again through the conveying of the circulating pump, the heat exchange pipe cools the backflow immersion liquid, and the process is repeated, so that the heat exchange efficiency is improved. And the low-temperature immersion liquid can uniformly and quickly flow through the surface of the battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery liquid cooling technical field especially relates to a kind of immersed battery liquid cooling device and energy storage battery package. BACKGROUND

[0002] In recent years, with the rapid development of electrochemical energy storage technology, immersed liquid cooling energy storage system gradually becomes the mainstream design scheme of large-capacity battery pack due to its high heat dissipation capacity and intrinsic safety, for example, Tesla patent US20210083221A1 forms the heat cycle of the up-down convection of immersed liquid by the density difference of immersed liquid caused by battery heating, specifically, the density of immersed liquid becomes smaller when heated, so the high-temperature immersed liquid rises and contacts with liquid cooling plate arranged at the top of immersed liquid, and the high-temperature immersed liquid is cooled after heat exchange with liquid cooling plate and then falls back to the bottom.

[0003] The current immersed cooling liquid natural convection cooling method for battery cooling has limited cooling effect, and the reason is that when the battery is subjected to high-rate charging and discharging, a large amount of heat is generated, and the position of heat exchange between high-temperature immersed liquid rising and low-temperature immersed liquid falling is in the middle of the battery, which causes the cooling capacity of low-temperature immersed liquid to be seriously lost when it falls to the bottom of the battery, and further causes a large temperature difference between the top and bottom of the battery, which affects the use of the battery. SUMMARY

[0004] Therefore, the utility model provides an immersed battery liquid cooling device and energy storage battery package to solve the problem of poor cooling effect of the current immersed cooling liquid natural convection cooling method for battery cooling.

[0005] The technical scheme of the utility model is implemented as follows: the utility model provides an immersed battery liquid cooling device, which is arranged in the shell of a battery pack, a plurality of batteries are arranged in the shell and immersed in heat-conducting medium, and the immersed battery liquid cooling device comprises a heat exchange pipe arranged in the shell and located at the top of the battery, the heat exchange pipe is immersed below the liquid level of the heat-conducting medium, a liquid delivery pipe arranged in the shell and located at the bottom of the battery, the liquid delivery pipe is provided with through holes, a circulating pump for pumping heat-conducting medium, wherein the position of the side wall of the shell close to the liquid level of the heat-conducting medium is provided with a backflow port, the backflow port is communicated with the liquid delivery pipe through the circulating pump, and the heat-conducting medium at the bottom of the shell is pumped through the through holes and then delivered to the top of the shell through the backflow port by the circulating pump.

[0006] On the basis of the above technical scheme, preferably, the immersed battery liquid cooling device further comprises a liquid storage tank in communication with the output end and the input end of the heat exchange pipe, the liquid storage tank stores cooling water, a delivery pump in communication between the liquid storage tank and the input end of the heat exchange pipe, and the delivery pump pumps cooling water to the heat exchange pipe, wherein the temperature difference between the surface of the battery and the heat-conducting medium is adjusted by adjusting the total delivery amount of the delivery pump per unit time.

[0007] Further preferably, gaps are left between adjacent batteries; the through holes arranged on each infusion pipe are arranged in a column, or the through holes arranged on each infusion pipe and corresponding in position are arranged in a column, and each column of through holes is arranged in alignment with a gap.

[0008] Further preferably, the calculation formula of the total amount of infusion of the infusion pump in a unit of time is,

[0009] q a = Q (A△T) -1 × (ρul) -1 / 2 × μ -1 / 6 × c p 1 / 3 × λ -2 / 3 × A0×n×k -1 ,

[0010] wherein Q is the heat generated during the charging and discharging of the battery, A is the contact area of the battery and the heat-conducting medium, △T is the temperature difference between the surface of the battery and the heat-conducting medium, ρ is the density of the heat-conducting medium, l is the height of the battery, u is the flow rate of the heat-conducting medium in the gap, μ is the viscosity of the heat-conducting medium, c p is the specific heat capacity of the heat-conducting medium, λ is the thermal conductivity of the heat-conducting medium, A0 is the horizontal cross-sectional area of the gap, n is the number of columns of through holes, and k is an empirical constant.

[0011] Further preferably, the flow rate of the heat-conducting medium in each gap is adjusted by adjusting the pumping flow rate of the circulating pump.

[0012] Further preferably, the infusion pipe comprises a plurality of branch pipes arranged in one-to-one correspondence in each gap, and a plurality of through holes are arranged on each branch pipe; a main pipe is connected in communication with one end of each branch pipe, one end of the main pipe extends through the shell to the external environment, and the other end of the main pipe is connected in communication with the return port by the circulating pump.

[0013] Further preferably, the distance between adjacent through holes in each column is 3-5 cm.

[0014] Further preferably, the width of the gap is not greater than 10 cm.

[0015] Based on the above technical solutions, preferably, the diameter of the through hole is 1-2 cm.

[0016] On the other hand, the utility model also provides a kind of energy storage battery pack, including above-mentioned immersion type battery liquid cooling device, still include shell and the plurality of batteries arranged in shell.

[0017] The immersion type battery liquid cooling device and the energy storage battery pack of the utility model have the following beneficial effects compared with the prior art:

[0018] (1) The immersion cooling liquid in the box is driven by a circulating pump, so that the immersion liquid flows through the gaps between the batteries from top to bottom to form a cooling flow channel, the low-temperature immersion liquid continuously exchanges heat with the battery pack generating heat in the charging and discharging process and takes away the heat of the battery, the high-temperature immersion liquid carrying heat is transported by the circulating pump and reflows to the top of the box, the heat exchange pipe cools the reflowing immersion liquid and repeats the above process, so that the low-temperature immersion liquid can uniformly and rapidly flow through the surface of the battery, and the cooling effect is weakened by locating the heat exchange position in the middle of the battery.

[0019] (2) The utility model discloses a temperature difference between the battery surface and the heat conduction medium is adjusted by adjusting the total amount of delivery pump in unit time, thereby controlling the flow rate of the heat conduction medium in the gap, which can accurately adjust the cooling rate according to the design requirement, and is helpful to improve the cooling effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0021] Figure 1 It is the perspective view of the immersion type battery liquid cooling device of the utility model;

[0022] Figure 2 It is the side sectional structure schematic view of the immersion type battery liquid cooling device of the utility model;

[0023] Figure 3 It is the perspective view of the infusion tube of the utility model.

[0024] In the drawing: 1, shell;11, backflow port;62, battery;201, gap;3, heat exchange pipe;4, infusion tube;41, branch pipe;42, main pipe;401, through hole;5, circulating pump;6, liquid storage tank;7, delivery pump. DETAILED DESCRIPTION

[0025] The technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model, obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0026] As Figure 1 shown, in combination with Figure 2The utility model discloses an immersed battery liquid cooling device, heat exchange pipe 3, liquid delivery pipe 4 and circulating pump 5.

[0027] Among them, the immersed battery liquid cooling device is arranged in the shell 1 of the battery pack, a plurality of batteries 2 are arranged in the shell 1 and the battery 2 is immersed in the heat conduction medium, the shell 1 is provided with the backflow port 11 at the position close to the liquid level of the heat conduction medium.

[0028] The heat exchange pipe 3 is arranged in the shell 1 and is located at the top of the battery 2, and the heat exchange pipe 3 is immersed in the liquid level of the heat conduction medium.

[0029] The liquid delivery pipe 4 is arranged in the shell 1 and is located at the bottom of the battery 2, and the liquid delivery pipe 4 is provided with the through hole 401.

[0030] The circulating pump 5 is used for pumping the heat conduction medium, the backflow port 11 is communicated with the liquid delivery pipe 4 through the circulating pump 5, and the heat conduction medium at the bottom of the shell 1 is pumped through the through hole 401 and then is transported to the top of the shell 1 through the backflow port 11 by the circulating pump 5.

[0031] When the above technical scheme is adopted, the heat conduction medium in the shell 1 is driven to flow by the circulating pump 5 arranged outside the shell 1, the heat conduction medium in the shell 1 is pumped by the circulating pump 5 through the liquid delivery pipe 4, the heat conduction medium cooled by the heat exchange pipe 3 flows from top to bottom through the gap 201 between the adjacent batteries, the heat conduction medium at the bottom of the shell 1 has been pumped away by the circulating pump 5, so that the low-temperature heat conduction medium flowing from top to bottom forms a cooling flow channel in the gap 201, the heat conduction medium flows in the gap 201 and exchanges heat with the battery 2 generating heat in the charging and discharging process and carries away the heat of the battery 2, the heat conduction medium at the bottom of the shell 1 enters the liquid delivery pipe 4 through the through hole 401 on the upper surface of the liquid delivery pipe 4 at the bottom of the battery 1, so that the high-temperature heat conduction medium is led out of the shell 1, the heat conduction medium after heat exchange is transported back to the heat exchange pipe 3 arranged at the top of the shell 1 through the backflow port 11 by the circulating pump 5, and the heat exchange pipe 3 cools the backflow heat conduction medium.

[0032] In Figure 2 A preferred embodiment shown in the figure further includes the liquid storage tank 6 and the delivery pump 7.

[0033] The storage tank 6 is connected with the output end and the input end of the heat exchange pipe 3, and the storage tank 6 stores cooling water.

[0034] The conveying pump 7 is a water pump, which is connected between the storage tank 6 and the input end of the heat exchange pipe 3, and the conveying pump 7 pumps the cooling water to the heat exchange pipe 3. In order to realize effective cooling of the battery 2, it is necessary to ensure that the heat conduction medium has a high flow rate in the gap 201, but the flow rate is difficult to measure accurately, so in the actual operation, the temperature difference between the surface of the battery 2 and the heat conduction medium is adjusted by adjusting the total amount of the conveying pump 7 in unit time. The greater the total amount of the conveying pump 7 in unit time, the faster the flow rate of the heat conduction medium in the gap 201, and the better the cooling effect.

[0035] In Figure 2 In a preferred embodiment shown in the figure, a gap 201 is left between adjacent batteries 2; the plurality of through holes 401 arranged on each infusion pipe 4 form a row, or the plurality of through holes 401 corresponding in position on each infusion pipe 4 form a row, and each row of through holes 401 is arranged in alignment with the gap 201, so that the heat conduction medium will not be hindered when entering the through hole 401, thereby reducing the flow rate of the heat conduction medium.

[0036] In Figure 2 In a preferred embodiment shown in the figure, the calculation formula of the total amount of the conveying pump 7 in unit time is,

[0037] q a = Q (A△T) -1 × (ρul) -1 / 2 × μ -1 / 6 × c p 1 / 3 × λ -2 / 3 × A0× n× k -1 , (1)

[0038] Wherein, Q is the heat generated in the charging and discharging process of the battery 2, A is the contact area of the battery 2 and the heat conduction medium, △T is the temperature difference between the surface of the battery 2 and the heat conduction medium, ρ is the density of the heat conduction medium, l is the height of the battery 2, u is the flow rate of the heat conduction medium in the gap 201, μ is the viscosity of the heat conduction medium, c p is the specific heat capacity of the heat conduction medium, λ is the thermal conductivity of the heat conduction medium, A0 is the horizontal cross-sectional area of the gap 201, n is the number of rows of through holes 401, and k is an empirical constant.

[0039] The derivation process of the above calculation formula is: according to the heat generated by the battery 1, the flow rate of the heat conduction medium in the gap 201 of each battery 1 is determined, and then the total flow of the conveying pump 7 can be known according to the flow rate of each heat conduction medium.

[0040] First, the required convective heat transfer coefficient is calculated according to the heat generated in the charging and discharging process of the battery,

[0041] h = Q (ΔT) -1 , (2)

[0042] Then, according to the obtained heat transfer coefficient h, the flow rate u of the gap channel of each battery pack is determined. Formula (2) can be converted to,

[0043] h = (ρul) -1 / 2 × μ -1 / 6 × c p 1 / 3 × λ -2 / 3 × k -1 , (3)

[0044] Further, the flow rate u is converted by formula (3). Wherein, k is the empirical relationship coefficient of the experimental relationship of the liquid outer flat plate, usually 0.664.

[0045] Again, according to the obtained flow rate, the flow rate of the heat conducting medium in the gap 201 of the battery 1 is determined by combining the following formula (4),

[0046] q = μ × A0, (4)

[0047] Finally, since the total flow of the delivery pump 7 is the sum of the flow of the heat conducting medium in all the gaps 201, formula (1) is obtained by combining formulas (2) to (4).

[0048] In a preferred embodiment shown in Figure 2 , the flow rate of the heat conducting medium in each gap 201 is adjusted by adjusting the pumping flow rate of the circulating pump 5, because the pumping flow rate of the circulating pump 5 substantially determines the flow rate of the heat conducting medium in the gap 201.

[0049] In a preferred embodiment shown in Figure 3 , the infusion tube 4 includes branch pipes 41 and a main pipe 42.

[0050] Wherein, a plurality of branch pipes 41 are arranged one by one in each gap 201, and a plurality of through holes 401 are arranged on the branch pipe 41. A sunken groove can be opened on the ground of the box 1, and the branch pipe 41 is arranged in the sunken groove. The pipe diameter of the branch pipe 41 is usually 3-5 cm, which needs to be designed according to the needs of the battery pack.

[0051] The main pipe 42 is connected with one end of the plurality of branch pipes 41 at the same time, one end of the main pipe 42 extends to the external environment through the shell 1, and the outer end of the main pipe 42 is connected with the return port 11 through the circulating pump 5. The pipe diameter of the main pipe 42 is 5-10 cm. The main pipe 42 functions to converge the plurality of branch pipes 41, an outlet can be arranged on the side bottom of the box 1, the output end of the main pipe 42 is connected with the outlet, and the outlet is connected with the circulating pump 7.

[0052] In Figure 2 In a preferred embodiment shown in the drawings, the pitch of the adjacent through holes 401 on each column is 3-5 cm. The pitch of the through holes 401 does not greatly affect the flow rate of the heat transfer medium in the gap 201, because the flow rate of the heat transfer medium in the gap 201 is essentially determined by the pumping flow rate of the circulating pump 5, but the pitch of the through holes 401 is too large to affect the pitch of the liquid flow formed by the heat transfer medium, thereby affecting the contact area of the heat transfer medium with the surface of the battery 2.

[0053] In Figure 2 In a preferred embodiment shown in the drawings, the width of the gap 201 is not greater than 10 cm. The width of the gap 201 is too large to make the liquid flow formed by the heat transfer medium difficult to form effective contact with the surface of the battery 2, thereby affecting the heat exchange effect, and will lead to the reduction of the number of batteries 2 arranged in the box 1, thereby affecting the energy storage performance; the width of the gap 201 is too small to reduce the flow passage cross-sectional area, resulting in the extension of the contact residence time of the oily heat transfer medium liquid flow with the surface of the battery 2, thereby affecting the flow rate of the heat transfer medium.

[0054] In Figure 2 In a preferred embodiment shown in the drawings, the diameter of the through hole 401 is 1-2 cm. The diameter of the through hole 401 is too small to hinder the heat transfer medium from entering the through hole 401, thereby adversely affecting the flow rate of the heat transfer medium; the diameter of the through hole 401 can be larger, but should not be greater than the width of the gap 201.

[0055] As Figure 1 shown, in combination Figure 2 The utility model discloses a kind of energy storage battery packs, including the immersion type battery liquid cooling device of any one embodiment described above, further include shell 1 and the several batteries 2 of being arranged in shell 1.

[0056] The above is only the preferred embodiment of the utility model, and does not limit the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An immersed battery liquid cooling device arranged in a shell (1) of a battery pack, wherein a plurality of batteries (2) are arranged in the shell (1) and the batteries (2) are immersed in a heat-conducting medium, characterized in that, The immersion type battery liquid cooling device comprises: a heat exchange pipe (3) arranged in the shell (1) and located at the top of the battery (2), the heat exchange pipe (3) being immersed in the liquid level of the heat conducting medium; a liquid delivery pipe (4) arranged in the shell (1) and located at the bottom of the battery (2), the liquid delivery pipe (4) being provided with through holes (401); a circulating pump (5) for pumping the heat conducting medium; wherein the shell (1) is provided with a backflow port (11) near the liquid level of the heat conducting medium, the backflow port (11) being connected with the liquid delivery pipe (4) through the circulating pump (5), and the heat conducting medium at the bottom of the shell (1) is pumped through the through holes (401) and then delivered to the top of the shell (1) through the backflow port (11) by the circulating pump (5).

2. The immersion type battery liquid cooling device according to claim 1, characterized by, Further comprising: a liquid storage tank (6) connected with the output end and the input end of the heat exchange pipe (3), the liquid storage tank (6) storing cooling water; a delivery pump (7) connected between the liquid storage tank (6) and the input end of the heat exchange pipe (3), the delivery pump (7) pumping the cooling water to the heat exchange pipe (3); wherein the temperature difference between the surface of the battery (2) and the heat conducting medium is adjusted by adjusting the total delivery amount of the delivery pump (7) per unit time.

3. The submersion type battery liquid cooling device according to claim 2, characterized by: Gaps (201) are left between adjacent batteries (2); the through holes (401) arranged on each liquid delivery pipe (4) form a row, or the through holes (401) arranged at corresponding positions on each liquid delivery pipe (4) form a row, and each row of through holes (401) is arranged in alignment with the gaps (201).

4. The submersion type battery liquid cooling device according to claim 3, characterized in that: The calculation formula of the total delivery amount of the delivery pump (7) per unit time is: q a = Q (A ΔT) -1 × (ρul) -1 / 2 × μ -1 / 6 × c p 1 / 3 × λ -2 / 3 × A0× n× k -1 , Wherein Q is the heat generated in the charging and discharging process of the battery (2), A is the contact area of the battery (2) and the heat conducting medium, ΔT is the temperature difference between the surface of the battery (2) and the heat conducting medium, ρ is the density of the heat conducting medium, l is the height of the battery (2), u is the flow rate of the heat conducting medium in the gap (201), μ is the viscosity of the heat conducting medium, c p is the specific heat capacity of the heat conducting medium, λ is the thermal conductivity of the heat conducting medium, A0 is the horizontal cross-sectional area of the gap (201), n is the number of columns of the through holes (401), and k is an empirical constant.

5. The submersion type battery liquid cooling device according to claim 4, characterized in that: The flow rate of the heat conducting medium in each gap (201) is adjusted by adjusting the pumping flow rate of the circulating pump (5).

6. The submersion type battery liquid cooling device according to claim 3, characterized in that: The liquid delivery pipe (4) comprises: a plurality of branch pipes (41) arranged one by one in each gap (201), the branch pipes (41) being provided with a plurality of through holes (401); a main pipe (42) connected with one end of each branch pipe (41), one end of the main pipe (42) extending to the outside environment through the shell (1), and the other end of the main pipe (42) being connected with the backflow port (11) through the circulating pump (5).

7. The submersion type battery liquid cooling device according to claim 6, characterized by: The distance between adjacent through holes (401) in each row is 3-5 cm.

8. The submersion type battery liquid cooling device according to claim 3, characterized by: The width of the gap (201) is not greater than 10 cm.

9. The submersion type battery liquid cooling device according to claim 1, characterized by: The diameter of the through hole (401) is 1-2 cm.

10. An energy storage battery pack characterized by: The immersion type battery liquid cooling device comprises: the shell (1) and a plurality of batteries (2) arranged in the shell (1).

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