An immersion type liquid-cooled energy storage battery box

Abstract

The present invention discloses an immersion-type liquid-cooled energy storage battery plug-in box, which relates to the technical field of energy storage batteries and comprises a lower box body and a box body upper cover, wherein the lower box body and the box body upper cover form a closed shell, wherein a module is arranged in the lower box body, and the lower box body is filled with an immersion liquid, wherein the immersion liquid covers the module located inside the lower box body, and the lower box body is composed of a liquid-cooled plate located at the bottom, a front side plate located at the front side, a rear side plate located at the rear side, a left side plate located at the left side, and a right side plate located at the right side. A heat exchange method is creatively proposed in which the immersion liquid can perform heat exchange contact with all surfaces of the battery module during heat exchange, thereby avoiding the dead angle problem of traditional oil cooling when cooling the battery module, and achieving sufficient heat exchange contact of the heat exchange medium with all surfaces of the battery module, having high heat exchange efficiency and balanced heat exchange effect, and no temperature difference will occur in the battery module itself.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage batteries, and in particular to an immersion type liquid-cooled energy storage battery plug-in box. Background Art

[0002] With the continuous development of the energy storage market, the energy density of energy storage battery systems is getting higher and higher, and the resulting battery heat dissipation problems and the chain safety problems that may be caused by this have received more and more attention from people in the industry. The existing lithium battery heat dissipation generally adopts air cooling or oil cooling. The existing air cooling efficiency is low, so oil cooling is currently used by many manufacturers. The existing oil cooling method generally immerses the battery module directly in the heat exchange medium for heat exchange. Regardless of whether the heat exchange medium can circulate, the battery module is fixedly installed so that one side cannot contact the heat exchange medium, resulting in uneven heat exchange of the battery module, affecting the energy storage function of the battery module, and has certain defects. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to provide an immersion-type liquid-cooled energy storage battery plug-in box, which solves the problems of uneven heat exchange efficiency and poor uniformity of battery cells in existing battery plug-ins.

[0004] Technical Solution

[0005] To solve the above problems, the technical solution provided by the present invention is:

[0006] An immersion-type liquid-cooled energy storage battery plug-in box comprises a lower box body and a box body upper cover, wherein the lower box body and the box body upper cover form a closed shell, wherein a battery module is arranged in the lower box body, and the lower box body is filled with an immersion liquid, wherein the immersion liquid covers the battery module located inside the lower box body, and wherein the lower box body is composed of a liquid-cooling plate located at the bottom, a front side plate located at the front side, a rear side plate located at the rear side, a left side plate located at the left side, and a right side plate located at the right side.

[0007] The immersion type liquid-cooled energy storage battery box is filled with immersion liquid, and the liquid cooling plate is provided with a plurality of liquid cooling channels. The immersion liquid flows through the liquid cooling plate and then flows into the immersion type liquid-cooled energy storage battery box.

[0008] A row of internal communication holes approximately parallel to the rear side plate is provided on the upper surface of the liquid cooling plate near the rear side plate of the lower box body, and the immersion liquid flows from the liquid cooling plate into the lower box body through the internal communication holes.

[0009] The liquid cooling plate extends outward from the outside of the front side plate, and a liquid inlet is provided on the liquid cooling plate located on the outside of the front side plate, and a liquid inlet interface is provided on the liquid inlet. A liquid drain port is provided on the front side plate, and the liquid drain port is connected to the interior of the lower box body, and a liquid drain interface is provided on the liquid drain port. The liquid inlet and the liquid drain port are arranged on different sides.

[0010] An internal connecting hole is provided on one side of the upper surface of the liquid cooling plate located inside the lower box body, and the internal connecting hole is connected to the interior of the lower box body. An end water outlet pipe is provided on the top of the front side plate inside the lower box body. The end water outlet pipe is a pipe arranged horizontally opposite to each other. A plurality of openings for immersion liquid to enter the end water outlet pipe are provided on the side of the end water outlet pipe facing the interior of the lower box body. The end water outlet pipe is arranged corresponding to the drain port and is connected to the drain port.

[0011] Through the above arrangement, the immersion liquid can exchange heat with all surfaces of the battery module during continuous circulation, thereby achieving a more efficient and balanced heat exchange effect.

[0012] There are multiple internal connecting holes and openings on the end water outlet pipe, and they are arranged with variable pitch. Several of the internal connecting holes are denser on the side away from the liquid inlet, and several of the openings on the water outlet pipe are denser on the side away from the discharge port. The internal connecting holes and the openings on the end water outlet pipe are arranged in opposite density. The closer the several internal connecting holes are to the liquid inlet, the farther the distance between adjacent internal connecting holes is. The closer the holes on the water outlet pipe are to the discharge port, the farther the distance between adjacent openings on the water outlet pipe is. Since the internal connecting holes and the water outlet pipes far from the liquid inlet and the discharge port have large flow resistance when the immersion liquid flows, the caliber and spacing need to be denser to ensure that the liquid flow rate of the inflow aperture is roughly consistent at a distance.

[0013] The left side plate and the right side plate are side plate structures with bottom plates, the left side plate and the right side plate are "L"-shaped plates, the sides of the left side plate and the right side plate are side plates, the bottoms of the side plates of the left side plate and the right side plate are bottom plates that abut against the liquid cooling plate and are of the same length as the liquid cooling plate, the side plates and the bottom plates of the left side plate and the right side plate are an integrated structure, and the side plates and the bottom plates of the left side plate and the right side plate are perpendicular to each other.

[0014] The bottom plate and the liquid cooling plate of the left side plate are at the same height as the bottom plate and the liquid cooling plate of the right side plate, and the bottom plate is a solid metal plate;

[0015] The liquid cooling plate is provided with a liquid cooling channel, which is a plurality of channels arranged side by side, and there are liquid cooling plate reinforcing ribs between adjacent liquid cooling channels. Due to the hollow setting of the liquid cooling plate, the tensile strength and yield strength of the bottom plate are stronger than those of the liquid cooling plate, and the liquid cooling plate reinforcing ribs are provided in the liquid cooling plate to enhance the strength of the liquid cooling plate.

[0016] Since the liquid cooling plate in the present invention needs to withstand the pressure of the battery module and the hydraulic pressure of the immersion liquid in the plug box, additional protection is required for the liquid cooling plate to ensure stable operation of the liquid cooling plate and prevent one or several flow channels from being flattened, resulting in failure of the entire liquid cooling plate.

[0017] Since the liquid cooling plate has a central control structure inside and needs to be filled with liquid, and at the same time, the liquid cooling plate serves as the main supporting component of the battery module, its hollow structure will result in the physical stiffness of the liquid cooling plate itself being slightly lower than the physical stiffness of the other solid components. Therefore, the liquid cooling plate is prone to deformation when supporting the battery module for a long time. Therefore, the bottom plates of the left and right plates are required to assist the liquid cooling plate in supporting the battery module. Since the bottom plates of the left and right plates are solid structures with higher physical rigidity, they are not easy to deform when assisting the liquid cooling plate in supporting the battery module.

[0018] For a more detailed solution, the flow channel of the liquid cooling plate can be varied, and any liquid cooling plate on the market that can achieve the technical effect of a metal liquid cooling plate can be used. Its main technical features are that the liquid cooling plate is configured as a sealed liquid cooling channel with a liquid inlet and a liquid outlet, and its flow channel design can adopt a combination of vertical and S-shaped flow channels in this application. The liquid cooling plate, the left side plate, and the right side plate are all provided with reinforcing ribs, and the liquid cooling plate, the front side plate, the rear side plate, the left side plate, the right side plate, and the support beam are all aluminum profiles;

[0019] The material of the liquid cooling plate can also be selected as an aluminum profile. Of course, in terms of design, the materials of the liquid cooling plate, the front side plate, the rear side plate, the left side plate, the right side plate and the support beam can be different, and it is not necessary to select aluminum profiles for all of them. There are two support beams on the liquid cooling plate close to the front side plate and the rear side plate. The support beam is horizontally mounted between the left side plate and the right side plate. One end of the support beam is fixed to the bottom plate of the left side plate, crossing the entire liquid cooling plate, and fixing the other end to the bottom plate of the right side plate. The two support beams are used to install the front and rear metal end plates of the four battery modules, and the two are connected by fastening bolts. The two support beams have the technical effect of sharing the mass of the battery module. Since the liquid cooling plate cannot bear force, for the purpose of protecting the liquid cooling plate, the two ends of the support beam are located on the bottom plates of the left and right plates. It can transfer most of the weight of the battery module to the floor of the left and right plates, greatly reducing the direct force on the liquid cooling plate.

[0020] The left side plate and the right side plate are both provided with reinforcing ribs, so as to further enhance the metal strength thereof, such as the compressive strength and the bending resistance.

[0021] The lower box contains immersion liquid, which flows to continuously exchange heat with the battery module.

[0022] Furthermore, the immersion liquid is hydrocarbon-based oil, fluorinated liquid or silicone oil.

[0023] Furthermore, the height of the inner side surface of the top of the upper cover of the box body from the flange surface of the lower box body is h1, the height of the flange surface of the lower box body from the bottom surface of the box body is h2, and the module shoulder height is h3, h2≥h3, h2 / 20≤h1≤h2 / 4, which can reduce the size h1 and increase the size h2. Considering that the core working mode of the immersion box requires the immersion liquid to immerse the battery module, based on this, the present invention sets h2≥h3. At the same time, considering the setting of the sealing ring between the lower box body and the upper cover, due to the long-term immersion of the sealing ring with the immersion oil, considering that the immersion liquid hydraulic pressure received by the sealing ring is p=ρgh, the immersion liquid pressure received by the sealing ring for a long time is directly related to the height of h1, so the present invention is motivated to reduce h1 as much as possible. However, since the CCS assembly needs to be set above the battery module, that is, the welding of the terminal, the connection of the aluminum bar, and the layout of the sensor signal line, it is also necessary to consider that the battery module provides downward pressure to the battery cell assembly through the pressing piece (not shown in the figure). At the same time, the injection hole and exhaust hole of the immersion liquid on the upper cover, as well as the explosion-proof valve, are also considered. In summary, it is necessary to maintain h1 at a certain height, which is also a design necessity. At the same time, we also pursue the shortening of h1. Therefore, the comprehensive setting of the present invention adopts the setting of h2≥h3, h2 / 20≤h1≤h2 / 4.

[0024] Furthermore, the left side plate and the right side plate are provided with hanging points, and the hanging points are welded to the right side plate and the left side plate by gas shielded welding or argon arc welding process.

[0025] Furthermore, the battery module is composed of a plurality of individual modules, each of which is composed of a plurality of battery cells, and a gap of not less than 4 mm is reserved between adjacent battery cells.

[0026] Furthermore, a 0.5 mm heat conductive structural adhesive is applied between the lower box and the battery module. The above structure is to better conduct the heat of the battery module to the liquid cooling plate. However, the design of the two support beams of the present invention greatly reduces the pressure caused by the direct contact between the lower box and the battery module.

[0027] Furthermore, the front side panel is provided with a positive high voltage plug, a negative high voltage plug, a BMU, a BMU protective cover, and a low voltage communication plug.

[0028] Furthermore, a box cover for connecting with the lower box to form a shell is provided on the top of the lower box, and a sealing gasket is provided at the connection position between the box cover and the lower box.

[0029] Furthermore, a PC insulating sheet is pasted inside the upper cover of the box body, and an explosion-proof valve, a liquid injection port for liquid injection, and an exhaust hole for exhaust are also provided on the upper cover of the box body.

[0030] Beneficial Effects

[0031] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0032] The present invention adopts a new solution for all-round cooling of the battery cell cycle, and creatively proposes a heat exchange method in which the immersion liquid can perform heat exchange contact with all surfaces of the battery module during heat exchange, thereby avoiding the dead angle problem of traditional oil cooling of the battery module, and achieving sufficient heat exchange contact of the heat exchange medium with all surfaces of the battery module, with high heat exchange efficiency and balanced heat exchange effect, and no temperature difference will occur in the battery module itself.

[0033] The present invention directly cools the battery cells through immersion liquid, effectively exchanges heat for the battery cells, reduces the temperature difference between the battery cells, improves the uniformity of the battery cells, and further improves the cycle life of the battery cells. The battery module is cooled through the dual cooling of static immersion and dynamic flow channel plates, which greatly improves the battery cooling efficiency, heat conduction, and battery temperature uniformity. It can cool not only through the heat conduction of the battery itself, but also through the heat conduction and heat convection of the immersion liquid, and its efficiency is greatly improved.

[0034] For extreme cases where the battery needs to be kept warm or heated, the present invention immerses the battery cell in an immersion liquid. A large amount of immersion liquid provides a large amount of heat capacity, which greatly improves the ability to stabilize the battery temperature. It can prevent the battery from heating up too quickly, when the immersion liquid absorbs heat; it can also prevent the battery from cooling down too quickly, when the immersion liquid can slowly release heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of a finished product of Example 1 of the present invention;

[0036] Figure 2 This is an explosion diagram of Example 1 of the present invention;

[0037] Figure 3 This is an exploded schematic diagram of the installation of components on the front side panel of Example 1 of the present invention;

[0038] Figure 4 This is a schematic diagram of installing a battery module in the lower box of Example 1 of the present invention;

[0039] Figure 5 This is an exploded schematic diagram of relevant components on the upper cover of the box body according to Embodiment 1 of the present invention;

[0040] Figure 6 This is an exploded schematic diagram of the lower box structure of Example 1 of the present invention;

[0041] Figure 7 A top view of the lower box and the battery module of Example 1 of the present invention;

[0042] Figure 8 for Figure 7 Sectional view of AA in the middle;

[0043] Fig. 9 This is a schematic diagram of the main flow channel of Example 1 of the present invention;

[0044] Fig.10 This is a diagram showing the liquid level of a battery plug box according to Example 1 of the present invention;

[0045] Fig.11 A top view of the internal communication holes of the battery plug box of Example 1 of the present invention;

[0046] Fig.12 This is an axonometric view of the end water outlet pipe of Example 1 of the present invention;

[0047] Fig.13 Schematic diagram of the flow of immersion liquid in the battery box of Example 1 of the present invention. DETAILED DESCRIPTION

[0048] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] Example 1

[0050] Combined with Figure 1-13 An immersion-type liquid-cooled energy storage battery plug-in box includes a lower box body 1 and a box body upper cover 5. The lower box body 1 is a rectangular shell structure that opens upward. The lower box body 1 and the box body upper cover 5 are combined to form a rectangular shell. The rectangular shell formed by the combination of the lower box body 1 and the box body upper cover 5 is the box body of the immersion-type liquid-cooled energy storage battery plug-in box. A battery module 2 is installed in the lower box body 1, and an immersion liquid that covers the battery module 2 is provided in the lower box body 1.

[0051] The lower box body 1 is composed of a liquid cooling plate 21 at the bottom, a front side plate 19 at the front side, a rear side plate 24 at the rear side, a left side plate 23 at the left side, and a right side plate 26 at the right side. The front end, rear end, and left and right ends of the liquid cooling plate 21 are respectively welded with the front side plate 19, the rear side plate 24, the left side plate 23, and the right side plate 26 by gas shielded welding to form a rectangular shell with an integrated structure, forming the lower box body 1, and the liquid cooling plate 21 is a hollow plate structure.

[0052] The left side plate 23 and the right side plate 26 are side plate structures with a bottom plate 50. The left side plate 23 and the right side plate 26 are "L"-shaped plates. The sides of the left side plate 23 and the right side plate 26 are side plates. The bottom of the side plate is a bottom plate 50 that is abutted against the liquid cooling plate 21 and is the same length as the liquid cooling plate 21. The thickness of the bottom plate 50 is the same as that of the liquid cooling plate 21, so the bottom plate 50 can also achieve the same supporting effect as the liquid cooling plate 21. The side plates and the bottom plate 50 of the left side plate 23 and the right side plate 26 are an integrated structure.

[0053] When the left side plate 23 and the right side plate 26 are not provided with the bottom plate 50 and are only directly installed on the liquid cooling plate with the side plates, since the liquid cooling plate 21 is a hollow structural plate, the liquid cooling plate 21 is affected by its hollow structure, and the hardness and rigidity of the liquid cooling plate 21 itself are relatively small. After the left side plate 23 and the right side plate 26 are installed on the liquid cooling plate 21 to form a lower box body 1 of a rectangular shell, and after the battery module 2 is installed to the lower box body 1, since the battery module 2 itself is heavy and immersion liquid is also provided in the lower box body 1, the liquid cooling plate 21 will be deformed, thereby causing the immersion liquid to leak.

[0054] When the left side plate 23 and the right side plate 26 are firstly abutted against the liquid cooling plate 21 through the bottom plate 50, and then fixed by welding the bottom plates 50 of the left side plate 23 and the right side plate 26 on both sides of the liquid cooling plate 21, since the left side plate 23 and the right side plate 26 are solid plates, their rigidity and hardness are greater than the liquid cooling plate 21. At this time, the left side plate 23 and the right side plate 26 can share part of the weight of the battery module 2, thereby avoiding the deformation of the liquid cooling plate 21 due to the influence of the battery module 2.

[0055] Among them, the liquid cooling plate 21 located on the inner side of the front side plate 19 and the rear side plate 24 is provided with a support beam 25 which is in contact with the front side plate 19 and the rear side plate 24 and is also welded as a whole by gas shielded welding. The support beam 25 is horizontally mounted between the left side plate 23 and the right side plate 26. One end of the two support beams 25 located on the front and rear sides is fixed to the bottom plate 50 of the left side plate 23, crossing the entire liquid cooling plate 21, and the other end of the support beam 25 is fixed to the bottom plate 50 of the right side plate 26. When installing the battery module 2, the battery module 2 is fixed by the support beam 25, and the battery module 2 can be The bolts are fixed on the support beam 25. The support beam 25 may be pre-set with threaded holes for fixing the battery module. At this time, the support beam 25 is simultaneously arranged on the left side plate 23, the liquid cooling plate 21, and the right side plate 26. The support beam 25 disperses the weight of the battery module 2. Part of the weight of the battery module 2 is dispersed to the bottom plate 50 of the left side plate 23 and the right side plate 26. The bottom plate 50 of the left side plate 23 and the right side plate 26 bears part of the weight of the battery module 2, thereby reducing the force on the liquid cooling plate 21, and further avoiding the liquid cooling plate 21 from being overloaded and deformed.

[0056] The support beam 25 located inside the lower box body 1 is also fixed to the bottom plate 50 of the left side plate 23 and the right side plate 26 and welded into an integrated structure by gas shielded welding. The support beam 25 can improve the strength and support of the four side panels in the lower box body 1.

[0057] The liquid cooling plate 21 , the left side plate 23 , and the right side plate 26 are all designed with reinforcing ribs on one side, which play a role in improving the overall strength and rigidity of the lower box body 1 .

[0058] The liquid cooling plate 21, the front side plate 19, the rear side plate 24, the left side plate 23, and the right side plate 26 are all made of aluminum, preferably aluminum profiles. The liquid cooling plate 21, the front side plate 19, the rear side plate 24, the left side plate 23, and the right side plate 26 have a tensile strength of not less than 160 MPa, a yield strength of not less than 110 MPa, an elongation at break of not more than 8%, a tensile modulus of not less than 68.9 GPa, a bending strength of not less than 180 MPa, and a melting temperature of 580-650 degrees Celsius.

[0059] The physical rigidity of the liquid cooling plate 21, the front side plate 19, the rear side plate 24, the left side plate 23, and the right side plate 26 forming the lower box 1 is a very important structural parameter. Since the liquid cooling plate 21 is a hollow structure, and in order to ensure the cooling efficiency, its aperture is often larger and the metal outer wall is thin, resulting in low physical rigidity of the liquid cooling plate 21, and its ability to withstand pressure and deformation is far inferior to that of a solid metal plate.

[0060] When preparing the lower box 1, since the battery module 2 needs to be installed in the lower box 1 and the battery module 2 is heavy, it is necessary to give additional consideration to the physical rigidity of the entire box. While ensuring the cooling effect of the lower box 1 on the battery module 2, it is also necessary to ensure that the liquid cooling plate 21 will not be deformed, resulting in leakage of the immersion liquid.

[0061] Therefore, the left side plate 23 and the right side plate 26 are reserved for welding the metal plate used as the bottom plate 50 and the liquid cooling plate 21 (see Figure 6 ), the left side plate 23 and the right side plate 26 are generally L-shaped, which has the physical effect of resisting deformation, pulling and compression of the entire body. The straight seams connecting the two sides of the liquid cooling plate 21 with the bottom plate 50 of the left side plate 23 and the right side plate 26 are welded into an integrated structure by gas shielded welding.

[0062] Secondly, in order to ensure its physical rigidity, the front side plate 19 and the rear side plate 24 are also welded to the front and rear ends of the above structure to ensure its physical rigidity. Furthermore, due to the physical rigidity of the liquid cooling plate 21 and the consideration of the fixation of the battery pack, two front and rear support beams 25 are welded in the width direction, so that the support beams 25 can provide sufficient physical rigidity and transfer the pressure of the battery pack to the left side plate 23 and the right side plate 26 to avoid the battery pack from crushing the liquid cooling plate 21 during long-term use.

[0063] The liquid cooling plate 21 and the front side plate 19 , the rear side plate 24 , the left side plate 23 , the right side plate 26 , and the support beam 25 constituting the lower box body 1 are all made of aluminum profiles, and the material grade is preferably 6061 or 6063.

[0064] It can be seen that the liquid cooling plate 21 is an independent entity. In other embodiments, the material of the liquid cooling plate 21 can be the same as that of the front side plate 19 , the rear side plate 24 , the left side plate 23 , and the right side plate 26 , or can be different.

[0065] The liquid cooling plate 21 is located on the outside of the left plate 23 and the right plate 26 and is provided with a plurality of lifting points 22, which are used to assist in carrying the submerged liquid-cooled energy storage battery plug-in box. There are multiple lifting points 22 on the same side, at least two, and when the lifting points 22 are used for transportation, the lower box body 1 can maintain balance without tilting. The lifting points 22 are limitedly arranged at the outer ends of the left plate 23 and the right plate 26. When more than two lifting points 22 are set, the remaining lifting points 22 are evenly and equidistantly arranged on the inner side of the lifting points 22 at both ends.

[0066] The hoisting point 22 can be welded and fixed to the liquid cooling plate 21, the left plate 23, and the right plate 26 as required, and the hoisting point 22 is fixed by gas shielded welding or argon arc welding.

[0067] The structural style of the lifting point 22 can be designed in a variety of ways, and can be designed into a corresponding structure according to the lifting equipment, so that when the lifting equipment and the lifting point 22 are coordinated, an efficient and stable connection can be achieved.

[0068] An intermediate layer is provided in the liquid cooling plate 21, and the intermediate layer is an independent space. The intermediate layer is used to set up a liquid cooling channel. A liquid inlet 27 is provided on the liquid plate 21. The liquid inlet 27 is located on the outside of the front side plate 19 of the liquid cooling plate 21. The position of the liquid inlet 27 is set on the front side of the lower box body 1. A liquid inlet interface 28 is provided on the liquid inlet 27. The liquid inlet interface 28 is used to communicate with a circulating pump of an external device. The circulating pump of the external device is connected to the liquid inlet interface 28 through a pipeline. The circulating pump of the external device will be used to inject the immersion liquid flowing in the liquid cooling plate 21 into the liquid cooling plate 21.

[0069] A drain port 30 is provided on the upper side of the front side plate 19, and the drain port 30 is connected to the interior of the lower box body 1. A drain interface 31 is provided on the drain port 30, and the drain interface 31 is used to be connected to a circulating pump of an external device. The circulating pump of the external device is connected to the drain interface 31 through a pipeline to lead the immersion liquid out of the lower box body 1. At this time, one side of the circulating pump of the external device is connected to the liquid inlet interface 28 to inject the low-temperature immersion liquid into the liquid cooling plate 21, and the other side is connected to the drain interface 31 to lead the immersion liquid with a raised temperature after heat exchange from the drain interface 31 for cooling so as to be injected into the liquid cooling plate 21 again for recycling.

[0070] An internal communicating hole 35 is provided on one side of the upper surface of the liquid cooling plate 21 located inside the lower box body 1. The internal communicating holes 35 are provided in plurality. The plurality of internal communicating holes 35 are all provided at one side of the liquid cooling plate 21 at one time and are connected to the liquid cooling channel inside the liquid cooling plate 21. The internal communicating holes 35 and the supporting beams 25 do not block each other. The internal communicating holes 35 are used to connect the immersion liquid in the liquid cooling plate 21 and flow into the lower box body 1. An end water outlet pipe 36 is provided on the top of the front side plate 19 inside the lower box body 1. The end water outlet pipe 36 is a pipe arranged horizontally. A plurality of openings for the immersion liquid to enter the end water outlet pipe 36 are provided on one side of the end water outlet pipe 36 facing the inside of the lower box body 1. The end water outlet pipe 36 is provided correspondingly to the drain port 30 and is connected to the drain port 30. The immersion liquid inside the lower box body 1 enters the end water outlet pipe 36 from the lower box body 1 and then converges and flows to the drain port 30. The end water outlet pipe 36 is used to discharge the immersion liquid in the lower box body 1 through the drain port 30.

[0071] When the battery is plugged in for use, the external circulation pump first passes the immersion liquid through the pipe between the liquid inlet interface 28 and the circulation pump, and pushes the immersion liquid into the liquid cooling channel in the liquid cooling plate 21 through the liquid inlet 27. The immersion liquid flows through the immersion channel of the entire liquid cooling plate 21. At this time, the immersion liquid fully exchanges heat with the bottom of the battery module 2, and the immersion liquid flows into the lower box body 1 from the internal connecting hole 35 of the liquid cooling plate 21. The immersion liquid flows in the lower box body 1 so that the immersion liquid is in full contact with the battery module 2 again. At this time, the immersion liquid fully exchanges heat with the battery module 2 again. The immersion liquid after heat exchange enters the end water outlet pipe 36 through the opening on the end water outlet pipe 36, and the circulation pump draws out the immersion liquid in the end water outlet pipe 36 through the discharge interface 31 to achieve recycling.

[0072] There are multiple internal connecting holes 35 and openings on the end water outlet pipe 36, and they are arranged with variable pitch. The side away from the liquid inlet 27 is denser, and the side away from the discharge port 30 is denser. The internal connecting holes 35 and the openings on the end water outlet pipe 36 are arranged in opposite density. The closer the internal connecting holes 35 are to the liquid inlet 27, the greater the distance between adjacent internal connecting holes 35. The closer the holes on the water outlet pipe 36 are to the discharge port 30, the greater the distance between adjacent openings on the water outlet pipe 36.

[0073] Since the internal connecting holes 35 and the water outlet pipe 36 far from the liquid inlet 27 and the liquid outlet 30 have a large flow resistance when the immersion liquid flows, the diameters and spacings need to be denser to ensure that the flow rate of the liquid flowing into the aperture is roughly the same at near and far distances.

[0074] The liquid cooling channel of the middle layer of the liquid cooling plate 21 preferably divides the middle layer space of the liquid cooling plate 21 into multiple liquid cooling channels, and liquid cooling channel reinforcement ribs are arranged between adjacent liquid cooling channels. Through such a main structure design, not only can the heat dissipation be better, but it also helps to strengthen the strength of the liquid cooling plate. Multiple liquid cooling channels are used for the flow of immersion liquid, which can make the flow of immersion liquid more stable.

[0075] The immersion liquid flows through the flow channel, and the immersion liquid is poured into the liquid inlet 27 through the liquid inlet interface 28 and enters the liquid cooling plate 21;

[0076] The above-mentioned liquid cooling channel is set as a conventional design in the art, or the conventional design of the cold plate flow channel known in the art can be introduced into the present invention.

[0077] It is important to note that the inlet 27 and the outlet 30 of the immersion liquid of the present invention are arranged on the outside of the front side plate 19. In this way, after the front plate 19 is welded to form the lower box body 1, the inlet 27 and the outlet 30 of the immersion liquid are directly arranged on the periphery of the lower box body 1 for easy connection.

[0078] A battery module 2 is installed in the lower box 1. The battery module is composed of several individual modules connected in series. Preferably, four individual modules are connected in series to form the battery module 2. Each individual module is composed of several individual cells connected in series. Preferably, each individual module has 12 cells.

[0079] A certain gap is set between adjacent battery cells in a separate module for full contact with the immersion liquid, ensuring that a 4mm gap is reserved between the battery cells in the battery module 2 in the BOL state, so as to ensure that the battery cell gap is not less than 2mm under EOL, so that the immersion liquid can be effectively filled between the two large surfaces of the battery cells, ensuring effective heat exchange of the battery cells, and effectively controlling the spread of thermal runaway of the battery cells.

[0080] The high voltage between the cells in the battery module 2 is connected by a series copper bus 3, and the individual modules are fixed by a fixing bracket 8 to form an integral module 2.

[0081] The bottom end surface inside the lower box body 1 is coated with 0.5mm thermal conductive structural adhesive. When the battery module 2 is installed on the support beam 25, the support beam 25 will support the battery module 2. At this time, there is a 0.5mm distance between the bottom surface of the battery module 2 and the liquid cooling plate 21, and this 0.5mm distance is used to coat the structural adhesive. The structural adhesive is coated on the surface of the liquid cooling plate 21 to fill the 0.5mm distance between the bottom surface of the battery module 2 and the liquid cooling plate 21, thereby fixing the battery module 2 in the lower box body 1, and effectively bonding and fixing the bottom surface of the battery cell in the battery module 2 to the liquid cooling plate 21 on the bottom surface of the box body through the structural adhesive, ensuring that the bottom battery cells do not have relative displacement during normal charging and discharging, thereby ensuring the effectiveness of the gap between the battery cells.

[0082] Each battery module 2 is provided with metal end plates (not marked) at both ends, and the above-mentioned metal end plates are connected to the front and rear support beams 25 by long bolts, so that the entire battery module 2 maintains good thermal contact with the liquid cooling plate by coating the structural adhesive on the bottom. At the same time, because the liquid cooling plate cannot bear force, the end plates at both ends of the battery module 2 transfer most of the gravity of the battery module 2 to the front and rear support beams 25, and the front and rear support beams 25 further transfer the gravity of the battery module 2 to the left plate 23 and the right plate 26 respectively.

[0083] A front side plate 19 is provided at the front side of the lower box body 1 , and a positive high voltage plug 9 , a negative high voltage plug 10 , a BMU 12 , a BMU protective cover 13 , and a low voltage communication plug 14 are provided on the front side plate 19 .

[0084] A positive high-voltage plug 9 and a negative high-voltage plug 10 are respectively installed on the front side plate 19 of the lower box body 1. The positive high-voltage connector 9 and the negative high-voltage connector 10 are arranged on the same side of the front side plate 19, and the positive high-voltage connector 9 and the negative high-voltage connector 10 are located on the same vertical line, which is convenient for user control and operation.

[0085] The BMU anti-slip cover 13 covers the BMU 12 to protect the BMU 12. To prevent liquid from the outside from penetrating into the communication port of the BMU 12, the installed BMU protective cover 13 needs to be waterproof so that external liquid water and gaseous water cannot enter the BMU protective cover 13 and contaminate the BMU 12.

[0086] In a general implementation, there are multiple low-voltage communication plugs 14, and several low-voltage communication plugs 14 are uniformly arranged and installed on the same side of the front side plate 19. The several low-voltage communication plugs 14 are plugs arranged in sequence, and the distances between adjacent several low-voltage communication plugs 14 are the same. The several low-voltage communication plugs 14 are at the same horizontal height, which is convenient for connection and control.

[0087] The positive high voltage plug 9, the negative high voltage plug 10, and the low voltage communication plug 14 must have a sealing protection level greater than or equal to IP67.

[0088] The top of the lower box body 1 is provided with a box cover 5 covering the upward opening of the lower box body, a PC insulating sheet 6 is adhered to the lower side of the box cover 5, and a sealing gasket 7 is provided between the PC insulating sheet 6 and the lower box body 1. During installation, the sealing gasket 7 is first installed above the battery module 2 in the lower box body 1, and then the box cover 5 with the PC insulating sheet 6 is covered on the lower box body 1. The sealing gasket has a better heat insulation effect and can improve the installation effect.

[0089] The upper cover 5 of the box body is a prefabricated component, and the PC insulating sheet 6 can be pasted on the upper cover 5 of the box body in advance. At the same time, an explosion-proof valve 4 is also provided on the upper cover 5 of the box body.

[0090] The upper cover 5 of the box body is also provided with a liquid injection port 15 for injecting liquid and an exhaust hole 16 for exhausting air. When the liquid injection port 15 and the exhaust hole 16 are not in use, they need to be blocked with a liquid injection port bolt 17 and an exhaust hole bolt 18 to form a closed space inside the battery box. The liquid injection port bolt 17 and the exhaust hole bolt 18 are bolts with sealing rings installed.

[0091] During normal use, check the connection of the high and low voltage harnesses inside the lower box 1. After they are fully connected, add immersion liquid into the lower box 1. The immersion liquid can make the battery module 2 have better temperature uniformity and ensure the temperature balance in the lower box 1. The immersion liquid is environmentally friendly and non-toxic hydrocarbon-based oil. In other embodiments, fluorinated liquid and silicone oil can also be used as cooling medium.

[0092] When the level of the immersion liquid approaches the flange surface of the lower box body 1, the liquid addition is stopped, and the prefabricated box body upper cover 5 is fixedly installed on the lower box body 1 by fasteners.

[0093] At this time, the immersion liquid inside the battery box is not full, and there is still some space where the immersion liquid can be further injected. Therefore, the liquid is further injected through the injection port 15 on the box cover 5, and the gas inside the box is discharged through the exhaust hole 16. After the immersion liquid is filled, the injection port bolt 17 and the exhaust hole bolt 18 are respectively installed on the box cover 5 to complete the entire battery box preparation work.

[0094] The interior of the submerged battery plug box is filled with immersion liquid. Since a sealing gasket 7 is installed at the flange surface of the lower box body 1, the height of the inner side surface of the top of the box cover 5 from the flange surface of the lower box body 1 is set to h1, the height of the flange surface of the lower box body 1 from the bottom surface of the box body is set to h2, and the shoulder height of the battery cell is set to h3. First, the height of the flange surface of the lower box body 1 from the bottom surface of the box body needs to be slightly greater than the shoulder height of the battery cell, that is, h2≥h3, and preferably the liquid level exceeds the busbar on the battery cell pole by 5-10mm. Considering that the sealing gasket 7 is affected by the pressure of the immersion liquid when immersed for a long time (P=ρgh), in order to improve the service life and sealing performance of the sealing gasket 7, the size h1 can be reduced and the size h2 can be increased, that is, the height design of the flange surface of the lower box body 1 is increased. The design scheme of the present invention needs to increase the size of h2 as much as possible, and at the same time, shorten the height of h1 as much as possible while ensuring the normal operation of the battery.

[0095] In the present invention, the immersion liquid can actually work normally as long as it immerses the entire battery pack, so it is preferred to consider h2≥h3. Taking into account the normal working conditions of the battery, the weight of the battery pack, and the immersion liquid pressure on the sealing part, the height of h1 is compressed as much as possible, and its height is preferably designed to be in the range of 1 / 20-1 / 5 of h2 to ensure the normal operation of the injection hole, the exhaust hole, and the explosion-proof valve.

[0096] Through the above technical solution, the immersion liquid used in the lower box 1 inside the battery plug box is in full contact with the battery cells in the battery module 2. There is no structural flow channel design inside the battery plug box. After the battery module 2 is normally fixed in the box, the immersion liquid is added through the liquid filling port. The immersion liquid is injected to a liquid level higher than the height of the battery module 2 and flows inside the box; except for the bottom of the battery cell, the five end faces of the remaining battery cells are effectively in contact with the immersion liquid for heat exchange. Under normal charging and discharging conditions, the temperature difference between the battery cells can be reduced to within 1°C. The immersion liquid is selected from hydrocarbon-based oil, fluorinated liquid, silicone oil, etc., and the battery cell is directly cooled by the immersion liquid to effectively exchange heat with the battery cell. Immersing the existing battery module 2 in the immersion liquid can greatly improve the heat exchange efficiency, reduce the temperature difference between the battery cells, improve the consistency of the battery cell performance, and thus improve the cycle life of the battery cell. At the same time, the battery cell is directly immersed in the immersion liquid, which can effectively prevent the thermal runaway of the battery cell from spreading to the adjacent battery cell, and the battery plug box does not need to increase the fire protection system design, reducing the material cost of the battery plug box.

[0097] In order to have a better heat exchange and cooling effect, the liquid cooling channel in the middle layer of the liquid cooling plate at the bottom of the lower box body 1 is used to dissipate heat from the bottom of the battery cell. The immersion liquid is introduced into the liquid cooling plate 21 at the bottom of the battery box body to replenish the immersion liquid into the box body and quickly exchange heat with the bottom of the battery module 2. The immersion liquid after heat exchange flows into the lower box body 1, and after heat exchange with the battery module 2 again, it is led out through a circulating pump.

[0098] The battery cells are cooled in accordance with the immersion and flow channel cooling methods, which can greatly reduce the temperature difference of the battery cells in the battery pack. A creative heat exchange method is proposed in which the immersion liquid can achieve heat exchange contact with all surfaces of the battery module during heat exchange, avoiding the dead angle problem of traditional oil cooling of the battery module, and achieving sufficient heat exchange contact of the heat exchange medium with all surfaces of the battery module. It has high heat exchange efficiency and balanced heat exchange effect, and there will be no temperature difference in the battery module itself.

[0099] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An immersion liquid-cooled energy storage battery box, characterized in that: The lower box body comprises a lower box body and a box body upper cover, wherein the lower box body and the box body upper cover form a closed shell, wherein a battery module is arranged in the lower box body, wherein the lower box body is filled with an immersion liquid, wherein the immersion liquid covers the battery module located inside the lower box body, and wherein the lower box body comprises a liquid cooling plate located at the bottom, a front side plate located at the front side, a rear side plate located at the rear side, a left side plate located at the left side, and a right side plate located at the right side; The immersion type liquid-cooled energy storage battery box is filled with immersion liquid, and the liquid cooling plate is provided with a plurality of liquid cooling channels, and the immersion liquid flows through the liquid cooling plate and then flows into the immersion type liquid-cooled energy storage battery box; A row of internal communication holes approximately parallel to the rear side plate is provided on the upper surface of the liquid cooling plate close to the rear side plate of the lower box body, and the immersion liquid flows from the liquid cooling plate into the lower box body through the internal communication holes; The liquid cooling plate extends outward from the front side plate, a liquid inlet is provided on the liquid cooling plate outside the front side plate, a liquid discharge port is provided on the front side plate, the liquid discharge port is connected to the interior of the lower box, and the liquid inlet and the liquid discharge port are arranged on different sides; An end water outlet pipe is provided at the top of the front side plate inside the lower box body. The end water outlet pipe is a pipe arranged horizontally. A plurality of openings for the immersion liquid to enter the end water outlet pipe are provided on one side of the end water outlet pipe facing the inside of the lower box body. The end water outlet pipe is arranged corresponding to the drain port and is connected to the drain port. There are multiple internal connecting holes and openings on the end water outlet pipe, and they are arranged at variable pitches. Some of the internal connecting holes are denser on the side away from the liquid inlet, and the holes on the water outlet pipe are denser on the side away from the liquid discharge port. The internal connecting holes and the openings on the end water outlet pipe are arranged in opposite density.

2. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The left side plate and the right side plate are side plate structures with bottom plates, the left side plate and the right side plate are "L"-shaped plates, the sides of the left side plate and the right side plate are side plates, the bottoms of the side plates of the left side plate and the right side plate are bottom plates that abut against the liquid cooling plate and are of the same length as the liquid cooling plate, the side plates and bottom plates of the left side plate and the right side plate are an integrated structure, the side plates and bottom plates of the left side plate and the right side plate are perpendicular to each other, the bottom plates of the left side plate and the right side plate are welded to the liquid cooling plate, and the tensile strength and yield strength of the bottom plates of the left side plate and the right side plate are both stronger than those of the liquid cooling plate; Two support beams are provided on the liquid cooling plate near the front side plate and the rear side plate. The support beam is horizontally connected between the left side plate and the right side plate. One end of the support beam is fixed to the bottom plate of the left side plate, crosses the entire liquid cooling plate, and the other end is fixed to the bottom plate of the right side plate.

3. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The height between the inner side of the top of the box cover and the flange surface of the lower box is h1, the height between the flange surface of the lower box and the bottom surface of the box is h2, and the shoulder height of the battery module is h3, h2≥h3, h2 / 20≤h1≤h2 / 4.

4. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The liquid cooling plate, the left side plate, and the right side plate are all provided with reinforcing ribs, and the liquid cooling plate, the front side plate, the rear side plate, the left side plate, the right side plate, and the support beam are all made of aluminum profiles.

5. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The immersion liquid is hydrocarbon-based oil, fluorinated liquid or silicone oil.

6. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The left side plate and the right side plate are provided with hanging points, and the hanging points are welded on the right side plate and the left side plate by gas shielded welding or argon arc welding process.

7. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The module is composed of a plurality of individual modules, each of which is composed of a plurality of battery cells, and a gap of not less than 4 mm is reserved between adjacent battery cells.

8. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: A 0.5 mm thermal conductive structural adhesive is applied between the lower box and the module.

9. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: The front panel is equipped with a positive high-voltage plug, a negative high-voltage plug, a BMU, a BMU protective cover, and a low-voltage communication plug.

10. The immersion type liquid-cooled energy storage battery box according to claim 1, characterized in that: A sealing gasket is provided at the connection position between the upper cover of the box body and the lower box body, a PC insulating sheet is pasted inside the upper cover of the box body, and an explosion-proof valve, a liquid injection port for liquid injection, and an exhaust hole for exhaust are also provided on the upper cover of the box body.

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