Immersed direct-cooling energy storage equipment

Abstract

The invention belongs to the technical field of energy storage equipment, and particularly relates to immersed direct-cooling energy storage equipment which comprises a side cooling structure, the side cooling structure is in contact with the side wall of a battery module, and a plurality of liquid inlet runners and liquid outlet runners are arranged in the side cooling structure. Each liquid inlet flow channel and each liquid outlet flow channel are wound along the side wall of a battery cell in the battery module one by one; when the direct cooling unit works, a refrigerant flows into the plurality of liquid inlet runners through the liquid inlet pipe, sequentially passes through the two sides of each battery module, and then the refrigerant in the plurality of liquid inlet runners flows into the plurality of liquid outlet runners and flows back along the two sides of each battery module; the box body is filled with immersion liquid, and the immersion liquid immerses the side cooling structure and the battery module; the invention aims to provide the immersed direct-cooling energy storage equipment which is good in temperature uniformity, high in heat dissipation efficiency and capable of completely eradicating heat spreading.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage equipment, and in particular to an immersion-type direct-cooling energy storage equipment. Background Art

[0002] An immersion battery pack is an energy storage device that directly immerses a battery module (consisting of multiple battery cells) in an immersion liquid. During normal operation, the chemical reaction inside the battery cell causes the center area of ​​the battery cell to generate a lot of heat. The battery cell tabs are the main channels for current in and out, and a large amount of heat will also be generated when a large current passes through. Therefore, the main heating area of ​​the battery pack is located in the middle and upper part of the battery cell, which is in direct contact with the battery cell through the immersion liquid. The heat in the middle and upper part of the battery cell is quickly transferred to the immersion liquid, thereby ensuring the uniform temperature inside the battery pack.

[0003] When the immersion battery pack is working, the temperature of the internal immersion liquid continues to rise, and "bottom liquid cooling + static immersion" or "flowing immersion" is generally adopted; in the "bottom liquid cooling + static immersion" scheme, a liquid cooling plate is set at the bottom of the battery pack, and the upper surface of the liquid cooling plate is in contact with the immersion liquid in the battery pack and the bottom of the battery module for heat dissipation, and the heating end of the battery module is concentrated in the middle and upper part. Although there is immersion liquid for temperature equalization, the bottom surface of the battery module occupies most of the area of ​​the liquid cooling plate, and only a small part of the liquid cooling plate is in contact with the immersion liquid, resulting in poor heat dissipation effect; in the "flowing immersion" scheme, the immersion liquid circulates directly in the battery pack. Although the heat dissipation effect of this scheme is better, the flowing immersion liquid will cause the battery pack box to bear greater pressure, and the structural strength and sealing performance requirements of the box are higher, which makes the box material cost higher. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide an immersion-type direct-cooling energy storage device with good temperature uniformity, high heat dissipation efficiency and heat spread prevention.

[0005] The technical solution adopted by the present invention is as follows: An immersion direct cooling energy storage device includes a battery pack, the battery pack includes a box body and a plurality of battery modules installed in the box body, and also includes a side cooling structure, the side cooling structure is in contact with the side wall of the battery module, and a plurality of liquid inlet flow channels and liquid outlet flow channels are arranged in the side cooling structure, each of the liquid inlet flow channels and liquid outlet flow channels is arranged one by one along the side wall of the battery cell in the battery module; When the direct cooling unit is working, the refrigerant flows into the multiple liquid inlet channels, passes through the two sides of each battery module in turn, and then the refrigerant in the multiple liquid inlet channels flows into the multiple liquid outlet channels, and then flows back along the two sides of each battery module; The box body is filled with an immersion liquid, and the immersion liquid immerses the side cooling structure and the battery module.

[0006] Compared with the prior art, the present invention has the following beneficial effects: 1. Both the inlet and outlet channels are in contact with the side walls of the battery module. Compared with the "bottom liquid cooling" solution, they are closer to the heating area of ​​the battery module (the middle and upper part of the battery module), and have better heat dissipation effect. The temperature of the refrigerant initially entering the battery pack is relatively low. As it passes through the battery modules in sequence, the temperature continues to rise. Therefore, the temperature of the refrigerant flowing out of the battery pack is relatively high. In this solution, both the inlet channel (the refrigerant temperature is relatively low) and the outlet channel (the refrigerant temperature is relatively high) pass through each battery pack, which can ensure the uniform temperature of each battery module in a single battery pack. 2. The tabs at the top of the battery module generate a lot of heat, but the immersion liquid immerses the battery module, and the heat near the tabs will be quickly transferred to the immersion liquid to achieve uniform temperature in the battery pack. Since the immersion liquid immerses the entire side cooling structure, compared with the cooling method using only the side cooling structure, the side cooling structure that is not in contact with the battery module will be in contact with the immersion liquid, which increases the heat exchange surface of the side cooling structure and improves the heat exchange efficiency. 3. When the temperature of the battery module does not reach a certain value, the direct cooling unit will not work. At this time, the battery module is still generating heat, which will cause a large temperature difference between the top and bottom of the battery module. In this solution, the immersion liquid can still achieve a uniform temperature effect when the direct cooling unit is not working.

[0007] 4. As the immersion liquid is flame-retardant and insulated, combined with the side cooling structure for cooling, the temperature around the battery module in thermal runaway can be quickly reduced, and thermal runaway will not be triggered; if the battery module is accidentally short-circuited, the insulating flame-retardant immersion liquid surrounds it, isolating the oxygen required for combustion, extinguishing the local combustion and thermal runaway caused by the short circuit, thereby preventing the spread of heat. Therefore, the immersion liquid can play a role in fire fighting; 5. When the battery pack fails and overheats, the internal pressure of the battery pack increases. In order to prevent the battery pack from exploding, the pressure relief valve on the battery pack will open and the electrolyte will flow out. In the "flow immersion" scheme, the electrolyte will be mixed in the immersion liquid. Subsequent maintenance requires the replacement of all the immersion liquid in the cycle, which has a high maintenance cost. In this scheme, only the immersion liquid in a single battery pack needs to be replaced; 6. Compared with the "flow immersion" solution, the immersion liquid in this solution is stationary in the battery pack, which reduces the requirements for the structural strength and sealing of the box, and can save material costs. In addition, this solution has a better heat dissipation effect through the combination of immersion liquid and side cooling structure, and can also meet the heat dissipation requirements; 7. Since the battery pack is filled with immersion liquid, condensation water cannot be generated inside, solving the condensation problem caused by low local temperature in conventional battery packs; 8. In the scheme of "bottom liquid cooling + static immersion", it is often half-immersed, with oxygen inside, and there is still a risk of heat spread. This scheme adopts "full immersion" to serve as an insulating oxygen-isolating heat dissipation medium to reduce the heating rate of the single cell when the thermal runaway occurs, thereby suppressing the degree and time of the thermal reaction and boiling reaction inside the single cell, thereby suppressing the thermal runaway of the single cell and the heat spread between the cells; 9. In this solution, "direct cooling + full immersion", even if the refrigerant leaks into the battery pack, since the refrigerant corresponding to the direct cooling unit will not affect the conductivity of the immersion liquid, compared with the liquid cooling unit (if the coolant used in the liquid cooling unit leaks, it will affect the conductivity of the immersion liquid and cause a short circuit between the battery cells), there is no risk of short circuit; therefore, it can be seen that if "liquid cooling + full immersion" is adopted, in order to avoid short circuits caused by leakage, the liquid cooling plate can only be set on the outside of the battery pack body, while this solution can set the corresponding side cooling structure in the battery pack and close to the battery cells, thereby improving the heat dissipation efficiency.

[0008] As a preferred embodiment of the present invention, the side cooling structure includes side cooling plates, which are arranged one by one along both sides of the battery module, and the plurality of liquid inlet channels and liquid outlet channels are arranged in the side cooling plates and arranged along the height direction of the side cooling plates; The side cooling structure also includes an internal transfer joint, and the liquid outlet ends of the plurality of liquid inlet channels and the liquid inlet ends of the liquid outlet channels are interconnected via the internal transfer joint.

[0009] Beneficial effects: 1. If multiple pipes are used as liquid inlet and outlet channels, the pipes need to be placed and fixed multiple times during installation. When welding pipes and joints, the position of each pipe and joint needs to be ensured, which is troublesome. The side cold plate in this solution can be integrated into the side cold plate by one-piece molding. During installation, only the side cold plate and the inner transfer joint need to be installed, which makes the installation simpler and more convenient. 2. Since the inlet and outlet channels are both located in the side cold plate, the inlet and outlet channels can exchange heat through the side cold plate itself, so that the difference between the inlet and outlet temperatures of the refrigerant is small, ensuring the uniform temperature of each battery module; 3. In the existing side cooling structure, a side cooling plate is installed on the side of each battery module, and a water inlet and a water outlet are respectively arranged at both ends of each side cooling plate. The liquid cooling pipeline is divided into multiple branch pipes and welded to each water inlet to form multiple side cooling plates in parallel. Although the above-mentioned parallel side cooling structure can concentrate the heat dissipation on the side wall of the battery module compared with the "bottom liquid cooling" method, the parallel pipes cause the internal coolant to be diverted, and there may be a problem of uneven flow, which in turn causes uneven cooling and heating of each battery module inside the battery pack. Although the side cooling structure in this scheme is also a parallel structure, each branch flow channel needs to pass through all battery modules. Even if the flow in each branch flow channel is uneven, it will not affect the temperature uniformity in the battery pack.

[0010] As a preferred embodiment of the present invention, the plurality of liquid inlet channels are located at the upper portion of the side wall of the battery module, and the plurality of liquid outlet channels are located at the lower portion of the side wall of the battery module.

[0011] Beneficial effect: The heating area of ​​the battery module is mainly in the middle and upper part. The refrigerant temperature of the liquid inlet channel is relatively low, making it close to the middle and upper part of the battery module side wall. Combined with the temperature equalization effect of the immersion liquid, the temperature uniformity in the battery pack is further ensured.

[0012] As a preferred embodiment of the present invention, the side cooling structure also includes an external adapter, which is installed on the front side of the box body, and is provided with a liquid inlet and a liquid outlet. The liquid inlet is connected to the liquid inlet pipe of the direct cooling unit, and the liquid outlet is connected to the liquid outlet pipe of the direct cooling unit. The liquid inlet ends of multiple liquid inlet channels are all connected to the liquid inlet, and the liquid outlet ends of multiple liquid outlet channels are all connected to the liquid outlet.

[0013] As a preferred embodiment of the present invention, the side cooling plate is a metal plate formed by aluminum extrusion.

[0014] Beneficial effect: The existing parallel side cooling structure uses plastic pipes and can only be applied to water cooling. Compared with plastic pipes, the aluminum extruded metal plate has higher structural strength and can therefore adapt to the pressure of the refrigerant flow.

[0015] Beneficial effects: In the existing parallel side cooling structure, the liquid inlet pipe and the liquid outlet pipe are located on the front and rear sides of the box body, and the liquid outlet pipe needs to go around to the back of the battery pack to connect with the liquid outlet, which makes the pipeline laying more complicated and the required length of the pipeline will also increase. During maintenance, it may be necessary to open the back panel of the battery cabinet. In this solution, by setting the external adapter, the liquid inlet end and the liquid outlet end of the side cooling structure are in the same position, which is more convenient to connect with the direct cooling unit. The length of the pipeline will not increase, and it is more convenient for maintenance. The existing parallel side cooling structure requires two through holes to be opened on the box body for installing the liquid inlet pipe and the liquid outlet pipe. In this solution, only a single through hole needs to be opened in the box body for installing the external adapter. Fewer through holes are opened, which can make the structural strength of the box body high and not easy to deform.

[0016] As a preferred embodiment of the present invention, the external adapter comprises an inner plate, an outer plate and two sealing sleeves, the inner plate is mounted on the inner wall of the box, the outer plate is mounted on the outer wall of the box, the inner plate is transversely provided with two tapered holes, the two tapered holes are respectively connected with a plurality of liquid inlet channels and liquid outlet channels, the outer plate is transversely provided with two first mounting holes corresponding to the two tapered holes, and the sealing sleeve passes through the corresponding first mounting holes, the outer wall of the box, and the tapered holes in sequence; The liquid inlet pipe or the liquid outlet pipe of the direct cooling unit is fixedly connected to the corresponding sealing sleeve.

[0017] Beneficial effect: By setting the tapered hole, the refrigerant in the liquid inlet channel and the liquid outlet channel can be collected, and then flow into or out of the liquid outlet pipe through the liquid inlet pipe, and the sealing sleeve itself is elastic and can be tightened in the tapered hole, so it can be quickly plugged in and out during installation and removal.

[0018] As a preferred embodiment of the present invention, the box body includes a bottom plate and an upper cover, the upper cover is detachably mounted on the bottom plate, the outer plate body and the inner plate body are both provided with a second mounting hole, and the second mounting hole is provided with a screw passing through the side wall of the upper cover.

[0019] Beneficial effect: When installing the box, the outer plate, upper cover and inner plate are fixed by screws, which is convenient for disassembly and assembly, and the inner plate and outer plate can block the through holes of the box through which the screws and sealing sleeves are installed, thus ensuring the sealing of the box.

[0020] As a preferred embodiment of the present invention, it also includes a cabinet and a direct cooling unit, the direct cooling unit is connected with a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe and the liquid outlet pipe are both arranged on the same side of the cabinet, the external adapter is arranged on the side of the battery pack close to the liquid inlet pipe and the liquid outlet pipe, and the liquid inlet pipe and the liquid outlet pipe are both provided with a plurality of branch pipes connected with the corresponding external adapters.

[0021] Beneficial effects: 1. The liquid inlet pipe and the liquid outlet pipe are both on the same side of the cabinet and close to the external adapter, which shortens the branch pipe length required for both, reduces the equipment cost, and makes the cabinet line distribution more concise. When the battery pack and the corresponding pipeline need to be removed for maintenance, only the single external adapter of the corresponding battery pack needs to be removed to open the upper cover; 2. The liquid inlet pipe and the liquid outlet pipe are on the same side of the cabinet. A single through hole can be opened on the cabinet to install the liquid inlet pipe and the liquid outlet pipe at the same time, which makes the installation simpler, reduces the number of holes in the cabinet, and simplifies the processing steps of the cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a first embodiment of an immersion-type direct-cooling energy storage device of the present invention; Figure 2 It is a structural schematic diagram of the side cooling structure in the first embodiment of the immersion direct cooling energy storage device of the present invention; Figure 3 It is a schematic diagram of the internal structure of the side cooling structure in the first embodiment of the immersion direct cooling energy storage device of the present invention.

[0023] The reference numerals include: cabinet 1, direct cooling unit 11, liquid inlet pipe 12, liquid outlet pipe 13, box body 14, side cold plate 21, liquid inlet channel 211, liquid outlet channel 212, inner adapter 22, outer adapter 23, inner plate 231, outer plate 232, sealing sleeve 233, tapered hole 234, first mounting hole 235, second mounting hole 236. DETAILED DESCRIPTION

[0024] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0025] In the description of the present application, the terms "first", "second", etc. are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the structure referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] Embodiment 1: See also Figure 1As shown, the immersed direct-cooling energy storage device of this embodiment includes a cabinet 1, the lower part of the cabinet 1 is an electrical compartment, and the upper part is a battery compartment. A direct cooling unit 11 is arranged in the electrical compartment, and a plurality of battery packs are vertically installed in the electrical compartment, each battery pack is provided with a side cooling structure, and the direct cooling unit 11 is connected with an inlet pipe 12 and an outlet pipe 13 for circulating refrigerant, the inlet pipe 12 and the outlet pipe 13 are located on the same side of the cabinet 1, and a plurality of branch pipes connected to the corresponding side cooling structures are arranged on the inlet pipe 12 and the outlet pipe 13; the battery pack includes a box 14 and a plurality of battery modules installed in the box 14, the box 14 includes an upper cover and a bottom plate, and the upper cover is detachably mounted on the bottom plate.

[0027] Among them, see Figure 2 As shown, the side cooling structure includes a side cooling plate 21, an inner adapter 22 and an outer adapter 23. The side cooling plate 21 is integrally formed and arranged one by one along both sides of the battery module. A plurality of liquid inlet channels 211 and liquid outlet channels 212 are arranged in the side cooling plate 21 and arranged along the height direction of the side cooling plate 21. A plurality of liquid inlet channels 211 are located at the upper part of the side wall of the battery module, and a plurality of liquid outlet channels 212 are located at the lower part of the side wall of the battery module. The liquid outlet end 211 and the liquid inlet end of the liquid outlet channel 212 are connected to each other through the internal adapter 22; the external adapter 23 is installed on the front side of the box body 14, and the external adapter 23 is provided with a liquid inlet and a liquid outlet, the liquid inlet is connected to the liquid inlet pipe 12 of the direct cooling unit 11, and the liquid outlet is connected to the liquid outlet pipe 13 of the direct cooling unit 11, the liquid inlet ends of multiple liquid inlet channels 211 are connected to the liquid inlet, and the liquid outlet ends of multiple liquid outlet channels 212 are connected to the liquid outlet.

[0028] Among them, see Figure 3 As shown, the external adapter 23 includes an inner plate 231, an outer plate 232 and two sealing sleeves 233. The inner plate 231 is installed on the inner wall of the box body 14, and the outer plate 232 is installed on the outer wall of the box body 14. The inner plate 231 is horizontally provided with two tapered holes 234, and the two tapered holes 234 are respectively connected with multiple liquid inlet channels 211 and liquid outlet channels 212. The outer plate 232 is horizontally provided with two first mounting holes 235 corresponding to the two tapered holes 234, and the sealing sleeve 233 passes through the corresponding first mounting holes 235, the outer wall of the box body 14, and the tapered holes 234 in sequence; the liquid inlet pipe 12 or the liquid outlet pipe 13 of the direct cooling unit 11 is fixedly connected to the corresponding sealing sleeve 233; the outer plate 232 and the inner plate 231 are both provided with a second mounting hole 236, and a screw passing through the side wall of the upper cover is provided in the second mounting hole 236.

[0029] Embodiment 2: On the basis of the first embodiment, there is a gap between each battery cell in a single battery module, the side wall between the battery cells is a large surface, and a vertical row of battery cells constitutes a battery module. The side cold plate 21 can pass vertically through the side of a single battery cell, and then be horizontally wound on the large surface of a single or multiple battery cells. After vertically winding a single battery cell, it continues to be horizontally wound until it passes through all the battery cells.

[0030] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An immersion direct cooling energy storage device, comprising a battery pack, wherein the battery pack comprises a box and a plurality of battery modules installed in the box, characterized in that: It also includes a side cooling structure, which is in contact with the side wall of the battery module, and is provided with a plurality of liquid inlet channels and liquid outlet channels, each of which is arranged one by one along the side wall of the battery cell in the battery module; When the direct cooling unit is working, the refrigerant flows into the multiple liquid inlet channels through the liquid inlet pipe, passes through the two sides of each battery module in turn, and then the refrigerant in the multiple liquid inlet channels flows into the multiple liquid outlet channels, and then flows back along the two sides of each battery module; The box body is filled with an immersion liquid, and the immersion liquid immerses the side cooling structure and the battery module.

2. The immersion direct cooling energy storage device according to claim 1, characterized in that: The side cooling structure includes side cooling plates, which are arranged one by one along both sides of the battery module, and the plurality of liquid inlet channels and liquid outlet channels are arranged in the side cooling plates and arranged along the height direction of the side cooling plates; The side cooling structure also includes an internal transfer joint, and the liquid outlet ends of the plurality of liquid inlet channels and the liquid inlet ends of the liquid outlet channels are interconnected via the internal transfer joint.

3. The immersion direct cooling energy storage device according to claim 1, characterized in that: The plurality of liquid inlet channels are located at the upper portion of the side wall of the battery module, and the plurality of liquid outlet channels are located at the lower portion of the side wall of the battery module.

4. The immersion direct cooling energy storage device according to claim 2, characterized in that: The side cold plate is a metal plate formed by aluminum extrusion.

5. The immersion direct cooling energy storage device according to claim 2, characterized in that: The side cooling structure also includes an external adapter, which is installed on the front side of the box body. A liquid inlet and a liquid outlet are provided on the external adapter. The liquid inlet is connected to the liquid inlet pipe of the direct cooling unit, and the liquid outlet is connected to the liquid outlet pipe of the direct cooling unit. The liquid inlet ends of multiple liquid inlet channels are all connected to the liquid inlet, and the liquid outlet ends of multiple liquid outlet channels are all connected to the liquid outlet.

6. The immersion direct cooling energy storage device according to claim 5, characterized in that: The external adapter comprises an inner plate, an outer plate and two sealing sleeves, wherein the inner plate is mounted on the inner wall of the box, and the outer plate is mounted on the outer wall of the box, wherein the inner plate is transversely provided with two tapered holes, and the two tapered holes are respectively connected with a plurality of liquid inlet channels and liquid outlet channels, and the outer plate is transversely provided with two first mounting holes corresponding to the two tapered holes, and the sealing sleeve passes through the corresponding first mounting holes, the outer wall of the box, and the tapered holes in sequence; The liquid inlet pipe or the liquid outlet pipe of the direct cooling unit is fixedly connected to the corresponding sealing sleeve.

7. The immersion direct cooling energy storage device according to claim 6, characterized in that: The box body comprises a bottom plate and an upper cover, wherein the upper cover is detachably mounted on the bottom plate, and the outer plate body and the inner plate body are both provided with a second mounting hole, wherein the second mounting hole is provided with a screw passing through the side wall of the upper cover.

8. The immersion direct cooling energy storage device according to claim 5, characterized in that: It also includes a cabinet and a direct cooling unit, the direct cooling unit is connected with a liquid inlet pipe and a liquid outlet pipe, the liquid inlet pipe and the liquid outlet pipe are both arranged on the same side of the cabinet, the external adapter is arranged on the side of the battery pack close to the liquid inlet pipe and the liquid outlet pipe, and the liquid inlet pipe and the liquid outlet pipe are both provided with a plurality of branch pipes connected with the corresponding external adapters.

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