Combined heat dissipation liquid cooling energy storage battery pack

Abstract

The invention relates to a combined heat dissipation liquid cooling energy storage battery pack which comprises module units, side liquid cooling systems, a top liquid cooling system and a water path connecting system. The module unit is formed by arranging a plurality of columns of modules in the second direction, and each column of modules comprises a plurality of linearly-arranged battery cells. The side face liquid cooling system is connected with first liquid cooling pipes on the two sides of each column of modules, and a sandwich structure with the first liquid cooling pipes and the modules arranged alternately is formed. And the top liquid cooling system is connected with a second liquid cooling pipe on the upper surface of each column of modules, the second liquid cooling pipe comprises a U-shaped pipe main body and a plurality of channels, and the channel paths avoid the cell explosion-proof valve area. The water path connecting system distributes total inlet water to all the first liquid cooling pipes; except the first liquid cooling pipe on the outermost side, the first water outlet pipes of the other first liquid cooling pipes are communicated with the water inlets of the corresponding second liquid cooling pipes; and the main water outlet pipe converges the water outlets of all the second liquid cooling pipes and the first water outlet pipes of the outermost first liquid cooling pipes. According to the invention, through top side double-path liquid cooling cooperative heat dissipation, the requirements of efficient heat dissipation, temperature equalization and safety protection are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery heat dissipation, in particular to a combined heat dissipation liquid cooling energy storage battery pack. BACKGROUND

[0002] With the increasing of energy crisis and environmental pollution, new energy vehicles with energy saving and environmental protection are developing rapidly. The power source of new energy vehicles is a large number of power batteries used in groups. The battery pack is compact in structure, and a large amount of heat is generated during high-rate charging and discharging of the battery, which is easy to accumulate, and the battery pack is easy to overheat locally or unevenly in temperature, which may lead to performance degradation and capacity attenuation of the battery, and even cause thermal runaway of the battery. When the battery pack is charged or discharged at high power, it generates a large amount of heat. For example, when a 314Ah battery is charged at a constant power of 1P, the heat generation power is 3-4 times that of 0.5P, which puts higher requirements on the heat dissipation environment of the battery.

[0003] At present, the energy storage battery pack mostly uses liquid cooling plate at the bottom for liquid cooling heat dissipation, and its heat dissipation capacity is limited. Moreover, the area near the pole of the battery cell has a large heat load, and single side or bottom heat dissipation is not suitable for the application scenario of high-power charging and discharging of large-capacity battery cells. The problems are as follows: 1. Insufficient heat dissipation: the bottom liquid cooling only covers the bottom surface of the battery cell, and the temperature of the pole area of the battery cell is higher than that of the bottom surface during high-power charging and discharging, forming a heat dissipation blind area. 2. Poor temperature uniformity: the flow channel of the profiled cooling plate is fixed, and the flow direction of the cooling liquid cannot be adjusted, resulting in a large temperature difference between the head and tail of the module, affecting the service life. 3. Low adaptability: it cannot be applied to the application scenario of high-power charging and discharging of large-capacity battery cells.

[0004] Therefore, there is an urgent need for a combined heat dissipation liquid cooling energy storage battery pack to solve the above problems. SUMMARY

[0005] The present application provides a combined heat dissipation liquid cooling energy storage battery pack to solve the above technical problems.

[0006] The technical solution of the present application to solve the above technical problems is as follows: A combined heat dissipation liquid cooling energy storage battery pack, comprising: a module unit, a side liquid cooling system, a top liquid cooling system and a waterway connection system; The module unit is composed of a plurality of modules arranged along a second direction, and each module is composed of a plurality of battery cells arranged linearly along a first direction; The side liquid cooling system: on both sides of each module along the second direction, a first liquid cooling pipe is connected through a heat conducting structure to form a sandwich structure of the first liquid cooling pipe and the module alternately arranged; Each of the first liquid cooling pipes includes a first inlet pipe and a first outlet pipe that run through the length of the module, as well as a parallel branch flow channel group; the parallel branch flow channel group consists of multiple independent branch flow channels, each branch flow channel corresponds to a single battery cell, and its two ends are respectively connected to the first inlet pipe and the first outlet pipe. The top liquid cooling system consists of a second liquid cooling pipe connected to the upper surface of each module via a heat-conducting structure, with an inlet and an outlet at each end. The second liquid cooling pipe is located between the positive and negative terminals of the battery cell, avoiding the area of ​​the battery cell's explosion-proof valve. The water connection system includes a main inlet pipe and a main outlet pipe; Among them, the main water inlet pipe is branched to the first water inlet pipe of all the first liquid cooling pipes; The first water outlet pipes of all the first liquid cooling pipes except the outermost one are connected one by one to the water inlet of the second liquid cooling pipes of each column of modules. The main outlet pipe connects to the outlets of all the second liquid cooling pipes and the first outlet pipe of the outermost first liquid cooling pipe.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the second liquid cooling pipe structure includes: a U-shaped pipe body and multiple channels; The U-shaped pipe body has an inlet and an outlet at its two ends, and includes two parallel straight pipe sections and a bend connecting the two straight pipe sections. Each of the channels is connected to two parallel straight pipe sections at both ends. The number of channels is the same as the number of modules, and the paths of all the channels avoid the cell explosion-proof valve area. Furthermore, the two ends of the U-shaped tube body are respectively the water inlet and the water outlet, which are staggered in the length and height directions of the module unit.

[0009] Furthermore, the branch flow channel adopts an O-type pipe, located in the middle of the side of the battery cell, with its two ends connected to the first water inlet pipe and the first water outlet pipe respectively to form a branch flow channel.

[0010] Furthermore, the cross-sections of the first liquid cooling pipe and the second liquid cooling pipe are rectangular flat structures.

[0011] Furthermore, the first liquid cooling pipe and the second liquid cooling pipe are made of aluminum or copper.

[0012] Furthermore, the thermally conductive structure is made of thermally conductive adhesive.

[0013] Furthermore, the surfaces of the first and second liquid cooling pipes that contact the battery cell are provided with micro-protruding honeycomb patterns, the patterns being composed of semi-elliptical protrusions; within the flow channel plane of the liquid cooling pipes, the long axis of the protrusions is parallel to the mainstream direction of the coolant.

[0014] Furthermore, a shape memory alloy valve plate is provided at the inlet of the O-type pipe and / or the channel. The valve plate partially covers the flow channel when the temperature is below the first temperature and deforms to expand the cross-sectional area of ​​the flow channel when the temperature is above the first temperature.

[0015] Furthermore, the shape memory alloy valve plate is a NiTi alloy sheet.

[0016] The beneficial effects of this invention are: 1. This implementation achieves simultaneous heat dissipation on the sides and top of the battery cell through a combined design of module units, a side liquid cooling system, a top liquid cooling system, and a water circuit connection system. The side liquid cooling system forms a sandwich structure with alternating first liquid cooling pipes and modules, directly covering the hot zone on the side of the battery cell; the top liquid cooling system precisely covers the high-temperature area between the positive and negative electrodes of the battery cell; the water circuit connection system connects the side and top liquid cooling pipes in series, reducing the number of external pipes and improving system compactness. The dual-path heat dissipation from the side and top increases the effective heat dissipation area and enhances heat dissipation capacity.

[0017] 2. This implementation adopts a parallel branch flow channel design, which greatly reduces the temperature difference of the cells in the module and effectively avoids local overheating.

[0018] 3. In this embodiment, the second liquid cooling pipe covers the high-temperature area of ​​the top electrode of the battery cell while avoiding the explosion-proof valve. This ensures that the pressure relief channel is unobstructed in case of thermal runaway while dissipating heat, thus ensuring good safety. Attached Figure Description

[0019] Figure 1 This is a perspective view of the combined heat dissipation liquid-cooled energy storage battery pack described in an embodiment of the present invention; Figure 2 This is a front view of the combined heat dissipation liquid-cooled energy storage battery pack described in an embodiment of the present invention; Figure 3 This is a side view of the combined heat dissipation liquid-cooled energy storage battery pack described in an embodiment of the present invention; Figure 4 This is a top view of the combined heat dissipation liquid-cooled energy storage battery pack described in an embodiment of the present invention.

[0020] The attached diagram lists the components represented by each number as follows: 1. Module; 11. Explosion-proof valve area for battery cells. 2. First inlet pipe; 22. First outlet pipe; 23. O-type pipe. 3. Straight pipe section; 32. Bend connection section; 33. Channel; 34. Inlet; 35. Outlet. 41. Main water inlet pipe; 42. Main water outlet pipe. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0024] Example A combined heat dissipation liquid-cooled energy storage battery pack, such as Figures 1-4 As shown, it includes: Module 1 unit, side liquid cooling system, top liquid cooling system and water connection system; The module 1 unit is composed of multiple columns of modules 1 arranged along the second direction, and each column of modules 1 is composed of multiple cells arranged linearly along the first direction. The side liquid cooling system: On both sides of each column of module 1 along the second direction, the first liquid cooling pipe is connected through a heat-conducting structure to form a sandwich structure in which the first liquid cooling pipe and module 1 are arranged alternately. Each of the first liquid cooling pipes includes a first water inlet pipe 21 and a first water outlet pipe 22 that run through the length of the module 1, as well as a parallel branch flow channel group; the parallel branch flow channel group is composed of multiple independent branch flow channels, each branch flow channel corresponds to a single battery cell, and its two ends are respectively connected to the first water inlet pipe 21 and the first water outlet pipe 22. The top liquid cooling system consists of a second liquid cooling pipe connected to the upper surface of each module 1 via a heat-conducting structure, with an inlet 34 and an outlet 35 at its two ends. The second liquid cooling pipe is located between the positive and negative terminals of the battery cell and avoids the battery cell explosion-proof valve area 11. The water connection system includes a main inlet pipe 41 and a main outlet pipe 42; Among them, the main water inlet pipe 41 is branched to the first water inlet pipe 21 of all the first liquid cooling pipes; The first water outlet pipe 22 of all the first liquid cooling pipes except the outermost one is connected to the water inlet 34 of the second liquid cooling pipe of each column of module 1. The main outlet pipe 42 connects to the outlets 35 of all the second liquid cooling pipes and the first outlet pipe 22 of the outermost first liquid cooling pipe.

[0025] This embodiment achieves simultaneous heat dissipation on the sides and top of the battery cell through a combined design of module 1, a side liquid cooling system, a top liquid cooling system, and a water circuit connection system. The side liquid cooling system forms a sandwich structure with the first liquid cooling pipe and module 1 arranged alternately, directly covering the hot area on the side of the battery cell; the top liquid cooling system precisely covers the high-temperature area between the positive and negative electrodes of the battery cell; the water circuit connection system connects the side and top liquid cooling pipes in series, reducing the number of external pipes and improving system compactness.

[0026] Specifically, such as Figure 4 As shown, the second liquid cooling pipe structure includes: a U-shaped pipe body and multiple channels 33; The U-shaped pipe body has an inlet 34 and an outlet 35 at its two ends, and includes two parallel straight pipe sections 31 and a bent pipe connecting section 32 connecting the two straight pipe sections 31. Each of the channels 33 is connected to two parallel straight pipe sections 31 at both ends. The number of channels 33 is the same as the number of cells in module 1, and the paths of all the channels 33 avoid the cell explosion-proof valve area 11. The U-shaped tube body has an inlet 34 and an outlet 35 at its two ends, which are staggered in the length and height of module 1.

[0027] Specifically, such as Figure 3 As shown, the branch flow channel adopts an O-type pipe 23, which is located in the middle of the side of the battery cell. Its two ends are respectively connected to the first water inlet pipe 21 and the first water outlet pipe 22 to form a branch flow channel.

[0028] In this embodiment, module 1 consists of 4 rows of single-row modules 1 arranged along the width direction (second direction), with each row containing multiple cells linearly arranged along the length direction (first direction). Each row of modules 1 has battery end plates at both ends. Five first liquid cooling pipes of the side liquid cooling system are alternately bonded to the 4 rows of modules 1, forming a sandwich structure. Four second liquid cooling pipes of the top liquid cooling system are bonded to the upper surface of each row of modules 1. In the water connection system, the main inlet pipe 41 branches to the 5 first liquid cooling pipes; the first outlet pipes 22 of the 1st to 4th first liquid cooling pipes connect to the corresponding second liquid cooling pipe inlets 34; the first outlet pipe 22 of the 5th first liquid cooling pipe and all second liquid cooling pipe outlets 35 converge into the main outlet pipe 42.

[0029] The second liquid cooling pipe is a U-shaped aluminum pipe. The main body of the U-shaped pipe includes two parallel straight pipe sections 31 and a U-shaped bend, with multiple independent channels 33 welded between them (corresponding to multiple battery cells). The path of the channels 33 bypasses the central area of ​​the battery cell explosion-proof valve. The main body of the U-shaped pipe connects the two straight pipe sections 31 through multiple parallel channels 33, so that the coolant flows evenly over the top of each battery cell, avoiding obstruction by the explosion-proof valve and improving the uniformity and safety of heat dissipation at the top. The inlet 34 and outlet 35 of the U-shaped pipe are staggered in length and height to prevent pipe interference and simplify the assembly process.

[0030] Each first liquid cooling pipe is equipped with multiple O-shaped pipes 23, which respectively cover the central area of ​​the side of a single cell. The O-shaped pipes 23 are attached to the middle position of the side of the cell (the area with the highest heat load) to specifically enhance heat dissipation, while the O-shaped structure enhances the rigidity of the pipes.

[0031] In a preferred embodiment, the cross-sections of the first liquid cooling pipe and the second liquid cooling pipe are rectangular flat structures.

[0032] In this embodiment, the cross-sections of the first and second liquid cooling pipes are rectangular with rounded ends. This flat structure increases the contact area between the heat dissipation pipes and the upper surface of the battery. The flat surfaces are attached to the battery cell, increasing the contact area between the first and second liquid cooling pipes and the battery cell, thus improving heat conduction efficiency.

[0033] The outer surfaces of the first and second liquid cooling pipes are coated with insulating varnish. To facilitate reduced flow resistance and flow rate adaptation, the main circuit and each parallel branch are set with different widths. In the first liquid cooling pipe, the first inlet pipe 21 and the first outlet pipe 22 form the main circuit, and the O-shaped pipe 23 forms the branch. The diameter of the first inlet pipe 21 and the first outlet pipe 22 is larger than that of the O-shaped pipe 23. In the second liquid cooling pipe, the U-shaped pipe body forms the main circuit, and the channel 33 forms the branch. The diameter of the U-shaped pipe body is larger than that of the channel 33.

[0034] In a preferred embodiment, the first and second liquid cooling pipes are made of aluminum or copper to ensure high thermal conductivity and corrosion resistance, meeting the requirements for long-term use.

[0035] In a preferred embodiment, the thermally conductive structure is made of thermally conductive adhesive.

[0036] In this embodiment, the thermally conductive structure uses silicon-based thermally conductive adhesive. The thermally conductive adhesive fills the gap between the liquid cooling pipe and the battery cell, eliminating contact thermal resistance and improving heat transfer efficiency.

[0037] The overall working process of this embodiment is as follows: Coolant is diverted from the main inlet pipe 41 of the water circuit connection system to the first inlet pipe 21 of the first liquid cooling pipe of all side liquid cooling systems; after flowing through the first inlet pipe 21, the coolant flows in two directions: the main stream flows along the first inlet pipe 21 to the end, and at the same time absorbs heat through each independent branch channel of the parallel branch channel group (corresponding to the side of a single cell), and then flows into the first outlet pipe 22; except for the outermost first liquid cooling pipe, the first outlet pipe 22 of the remaining first liquid cooling pipes delivers the coolant one by one to the second liquid cooling pipe inlet 34 of the top liquid cooling system of each column of modules 1. The coolant flows through multiple channels 33 of the second liquid cooling pipe (avoiding the cell explosion-proof valve area 11) to absorb the top heat and then is discharged from the outlet 35; the first outlet pipe 22 of the outermost first liquid cooling pipe and the outlets 35 of all second liquid cooling pipes finally flow into the main outlet pipe 42, completing the cooling cycle.

[0038] Example 2 This embodiment adds micro-protruding honeycomb texture and shape memory alloy valve plate to the original embodiment.

[0039] The surfaces of the first and second liquid cooling tubes that contact the battery cell are provided with micro-protruding honeycomb patterns, which are composed of semi-elliptical protrusions; in the flow channel plane of the liquid cooling tubes, the long axis of the protrusions is parallel to the mainstream direction of the coolant.

[0040] In this embodiment, the surfaces of the first and second liquid cooling pipes that contact the battery cell are processed with a micro-protruding honeycomb texture, which is composed of a semi-elliptical array of protrusions. The long axis of the protrusions is parallel to the flow direction of the coolant, and the grooves between the protrusions are filled with silicon-based thermally conductive adhesive. The long axis of the micro-protruding honeycomb texture is parallel to the flow direction of the coolant, which disturbs the fluid to form turbulence, breaks the boundary layer, and enhances the heat transfer coefficient. The height of the protrusions is designed to allow for deformation space, maintaining good contact pressure during the expansion of the battery cell during charging and discharging.

[0041] In a preferred embodiment, a shape memory alloy valve is provided at the inlet of the O-type pipe 23 and the channel 33. The valve partially covers the flow channel when the temperature is below the first temperature and deforms to expand the cross-sectional area of ​​the flow channel when the temperature is above the first temperature.

[0042] The shape memory alloy valve plate is a NiTi alloy sheet.

[0043] In this embodiment, a shape memory alloy valve is installed at the inlet of the O-ring 23 of the side liquid cooling plate. The valve is a thin NiTi alloy sheet with a gold-plated surface for corrosion protection. The valve is horizontally fixed to the top of the flow channel by a copper bracket, spaced apart from the side of the battery cell, with a thick thermally conductive silicone pad placed between them to achieve temperature conduction.

[0044] The specific workflow is as follows: Low temperature operation: When the temperature is ≤45℃, the valve plate remains flat, covering 50% of the flow channel cross section, limiting the flow rate to maintain the temperature uniformity of module 1; High-temperature conditions: When the temperature is >45℃, the valve plate deforms into an arch shape due to heat, and the effective cross-section of the flow channel expands to 150% of the original area, which specifically enhances the heat dissipation capacity of the high-heat area. Failure protection: A 0.3mm wide bypass slit downstream of the valve plate can provide basic flow to ensure system safety in the event of valve plate jamming.

[0045] This shape memory alloy valve reduces the cross-sectional area of ​​the flow channel at low temperatures to balance the flow rate of each branch; at high temperatures, it expands the flow channel to preferentially cool the overheated battery cell, achieving adaptive temperature control. The NiTi alloy sheet provides a stable shape memory effect and fatigue life, ensuring the reliability of the shape memory alloy valve.

[0046] It should be noted that the O-type pipe 23 inlet is equipped with a shape memory alloy valve, which is suitable for scenarios with high requirements for temperature difference of a single cell; the channel 33 inlet is equipped with a shape memory alloy valve, which is suitable for scenarios with stronger heat dissipation requirements in the electrode area.

[0047] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the methods, systems, and devices described above are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A combined heat dissipation liquid cooling energy storage battery pack, characterized in that: include: Module unit, side liquid cooling system, top liquid cooling system and water connection system; The module unit is composed of multiple columns of modules arranged along the second direction, and each column of modules is composed of multiple cells arranged linearly along the first direction; The side liquid cooling system: On both sides of each column of modules along the second direction, a first liquid cooling pipe is connected through a heat-conducting structure to form a sandwich structure in which the first liquid cooling pipe and the module are arranged alternately. Each of the first liquid cooling pipes includes a first inlet pipe and a first outlet pipe that run through the length of the module, as well as a parallel branch flow channel group; the parallel branch flow channel group consists of multiple independent branch flow channels, each branch flow channel corresponds to a single battery cell, and its two ends are respectively connected to the first inlet pipe and the first outlet pipe. The top liquid cooling system consists of a second liquid cooling pipe connected to the upper surface of each module via a heat-conducting structure, with an inlet and an outlet at each end. The second liquid cooling pipe is located between the positive and negative terminals of the battery cell, avoiding the area of ​​the battery cell's explosion-proof valve. The water connection system includes a main inlet pipe and a main outlet pipe; Among them, the main water inlet pipe is branched to the first water inlet pipe of all the first liquid cooling pipes; The first water outlet pipes of all the first liquid cooling pipes except the outermost one are connected one by one to the water inlet of the second liquid cooling pipes of each column of modules. The main outlet pipe connects to the outlets of all the second liquid cooling pipes and the first outlet pipe of the outermost first liquid cooling pipe.

2. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The second liquid cooling pipe structure includes: a U-shaped tube body and multiple channels; The U-shaped pipe body has an inlet and an outlet at its two ends, and includes two parallel straight pipe sections and a bend connecting the two straight pipe sections. Each of the channels is connected to two parallel straight pipe sections at both ends. The number of channels is the same as the number of modules, and the paths of all the channels avoid the cell explosion-proof valve area.

3. The combined heat dissipation liquid cooling energy storage battery pack according to claim 2, characterized in that: The two ends of the U-shaped tube body are the water inlet and the water outlet, respectively, which are staggered in the length and height directions of the module unit.

4. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The branch flow channel adopts an O-type pipe, located in the middle of the side of the battery cell, and its two ends are respectively connected to the first water inlet pipe and the first water outlet pipe to form a branch flow channel.

5. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The first liquid cooling pipe and the second liquid cooling pipe have rectangular flat cross-sections.

6. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The first liquid cooling pipe and the second liquid cooling pipe are made of aluminum or copper.

7. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The thermally conductive structure uses thermally conductive adhesive.

8. The combined heat dissipation liquid cooling energy storage battery pack according to claim 1, characterized in that: The surfaces of the first and second liquid cooling tubes that contact the battery cell are provided with micro-protruding honeycomb patterns, which are composed of semi-elliptical protrusions; in the flow channel plane of the liquid cooling tubes, the long axis of the protrusions is parallel to the mainstream direction of the coolant.

9. The combined heat dissipation liquid cooling energy storage battery pack according to claim 4, characterized in that: The O-type pipe and / or the inlet of the channel is provided with a shape memory alloy valve plate. The valve plate partially covers the flow channel when the temperature is below the first temperature and deforms to expand the cross-sectional area of ​​the flow channel when the temperature is above the first temperature.

10. The combined heat dissipation liquid cooling energy storage battery pack according to claim 9, characterized in that: The shape memory alloy valve plate is a NiTi alloy sheet.

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