Energy storage module with uniform internal temperature and external heat dissipation

Abstract

The present invention provides an energy storage module with uniform internal temperature and external heat dissipation, which includes a battery module. The energy storage module with uniform internal temperature and external heat dissipation includes an internal circulation system and an external circulation system. The internal circulation system includes a hot-end temperature equalizing plate covering at least one side of the battery module to absorb the heat of the battery module. The external circulation system includes a cooling device. The external circulation system is arranged on one side of the internal circulation system to absorb the heat absorbed by the internal circulation system from the battery module and dissipate it through the cooling device.

Description

Technical Field

[0001] The present invention relates to the technical field of battery energy storage, and in particular to an energy storage module with internal uniform temperature and external heat dissipation. Background Art

[0002] Battery energy storage technology has the functions of peak and frequency regulation, improving power distribution quality, and smoothing fluctuations in renewable energy power generation. It plays a very important role in improving traditional power grids and efficiently utilizing new energy, and its application is becoming more and more extensive.

[0003] In a battery energy storage system, numerous batteries are tightly packed together in a single space, and their operating conditions are complex and variable, sometimes operating at high rates and sometimes at low rates. This can easily lead to problems such as uneven heat generation, uneven temperature distribution, and large temperature differences between batteries. Temperature significantly impacts all aspects of battery performance. Excessively high temperatures and large temperature differences are detrimental to battery performance. Over time, this can inevitably lead to a decline in the charge and discharge performance, capacity, and lifespan of some batteries, impacting the performance of the entire battery energy storage system. In severe cases, thermal runaway can occur, leading to accidents.

[0004] In recent years, to meet the demands of commercial energy storage, battery energy storage systems have been developing towards larger capacity, higher rates, and cascade utilization. Consequently, the heat generated by these systems has also increased. A major technical challenge for current battery energy storage systems is ensuring that a large number of batteries within a given space operate within a suitable temperature range and maintain a relatively uniform temperature distribution. Existing battery energy storage systems mostly use air conditioning to regulate the air temperature in aisles, allowing heat exchange between the battery modules and the air in the aisles—that is, the aisle air cools the battery modules. However, since the aisle air cannot promptly cool batteries farther away from the aisles, problems such as uneven temperature distribution and large temperature differences between battery modules can easily occur, seriously impacting the performance and lifespan of the energy storage system. Furthermore, the air cools slowly, and when the temperature of some battery modules rises rapidly, posing a risk of thermal runaway, the air cannot quickly and promptly cool the battery modules. Therefore, existing solutions are no longer able to meet the thermal management requirements of future battery energy storage systems. Summary of the Invention

[0005] The purpose of the present invention is to provide an energy storage module that allows the battery to maintain a uniform temperature inside and dissipate heat outside, so as to solve the problems of uneven temperature distribution and large temperature differences between batteries.

[0006] To solve the above technical problems, the present invention provides an energy storage module with internal temperature uniformity and external heat dissipation, which includes a battery module. The energy storage module with internal temperature uniformity and external heat dissipation includes an internal circulation system and an external circulation system. The internal circulation system includes a hot-end heat spreader covering at least one side of the battery module to absorb and evenly distribute the heat of the battery module. The external circulation system includes a cooling device. The external circulation system is disposed on one side of the internal circulation system to absorb the heat absorbed by the internal circulation system from the battery module and dissipate it through the cooling device.

[0007] Optionally, the energy storage module with internal temperature uniformity and external heat dissipation further includes a cold-end heat sink. The external circulation system is disposed on one side of the internal circulation system and the external circulation system and the internal circulation system are connected through the cold-end heat sink.

[0008] Optionally, the internal circulation system includes an inner flow channel, and the external circulation system includes an outer flow channel. Both the inner flow channel and the outer flow channel are disposed inside the cold-end heat sink, and both the inner flow channel and the outer flow channel are arranged in an inclined grid pattern.

[0009] Optionally, both the inner flow channel and the outer flow channel are inclined.

[0010] Optionally, the internal circulation system further includes an air outlet pipe, a liquid outlet pipe, a liquid collector, and a serpentine pipe. The inlet of the liquid collector is communicated with the inner flow channel of the cold-end heat sink through the liquid outlet pipe, and the outlet of the liquid collector is communicated with the hot-end heat spreader through the serpentine pipe.

[0011] Optionally, at least one flow channel is provided inside the hot-end heat spreader, and each flow channel is filled with a refrigerant. The two ends of the flow channel are respectively communicated with the two ends of the inner flow channel.

[0012] Optionally, each flow channel includes at least one refrigerant endothermic phase change pool. At least one refrigerant endothermic phase change pool has a high-level port and a low-level port, and the high-level port and the low-level port are respectively communicated with the two ends of the inner flow channel.

[0013] Optionally, each flow channel further includes a liquid separation chamber, at least one liquid separation branch, at least one gas outlet branch, and a gas collection chamber. The inlet of the liquid separation chamber is communicated with one end of the inner flow channel, the outlet of the liquid separation chamber is communicated with each liquid separation branch, the low-level port of each refrigerant endothermic phase change pool is communicated with one of the liquid separation branches, the high-level port of each refrigerant endothermic phase change pool is communicated with one of the gas outlet branches, each gas outlet branch is connected to the gas collection chamber, and the outlet of the gas collection chamber is communicated with the other end of the inner flow channel.

[0014] Optionally, the gas outlet branch and the liquid separation branch are perpendicularly arranged.

[0015] Optionally, each liquid separation branch is communicated with a plurality of low-level ports, and each gas outlet branch is communicated with a plurality of high-level ports.

[0016] In summary, the modular energy storage module with uniform internal temperature and external heat dissipation of the present invention solves the problems of uneven temperature distribution and large temperature difference between batteries in the battery module by setting up an internal circulation system to evenly distribute the heat of the battery module and an external circulation system to dissipate the heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the modular energy storage module with uniform internal temperature and external heat dissipation provided by the embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the internal flow channel of the hot end heat sink plate and a partial enlarged view provided by the embodiment of the present invention;

[0019] Figure 3 are respectively the front view of the internal flow channel of the cold end heat sink plate, the top view of the inner flow channel and the top view of the outer flow channel provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following further describes in detail the specific embodiments of the present invention in conjunction with the drawings and embodiments. The following examples are used to illustrate the present invention but not to limit the scope of the present invention.

[0021] The directions shown in the drawings in the present invention all represent the flow directions.

[0022] Please refer to Figure 1 and Figure 3 . The embodiment of the present invention provides a modular energy storage module with uniform internal temperature and external heat dissipation. The modular energy storage module includes a battery module. The energy storage module with uniform internal temperature and external heat dissipation includes an internal circulation system 20 and an external circulation system 10. The internal circulation system 20 includes a hot end heat sink plate covering at least one side of the battery module to absorb and evenly distribute the heat of the battery module. The external circulation system 10 includes a cooling device. The external circulation system 10 is arranged on one side of the internal circulation system 20 to absorb the heat absorbed by the internal circulation system 20 from the battery module and dissipate it through the cooling device.

[0023] The modular energy storage module with uniform internal temperature and external heat dissipation of the present invention solves the problems of uneven temperature distribution and large temperature difference between batteries in the battery module by setting up the internal circulation system 20 to evenly distribute the heat of the battery module and the external circulation system 10 to dissipate the heat.

[0024] The side of the battery module in the present invention refers to the side with the largest surface area of the battery module. In this embodiment, the battery module is composed of a single row of multiple single cells arranged, and the hot-end heat spreader is provided on both sides of the battery module. The width direction of the hot-end heat spreader is greater than or equal to the sum of the widths of all single cells to ensure that the hot-end heat spreader covers each single cell. More preferably, the width of the hot-end heat spreader in this embodiment is 3 mm wider than that of the battery module 800. In other embodiments, it can also be any number within the range of 2 to 5 mm, such as 2 mm, 5 mm, 4 mm, etc. The height of the hot-end heat spreader is set such that at least the main reaction heat generation area of the cell is covered. More preferably, the height of the hot-end heat spreader is approximately equal to the height of the single cell. The height of the hot-end heat spreader in this embodiment is 3 mm less than that of the battery module 800. In other embodiments, it can also be any number within the range of 2 to 5 mm, such as 2 mm, 5 mm, 4 mm, etc.

[0025] In other embodiments, the single cells can also be combined in multiple rows. The hot-end heat spreader is provided not only on the outermost two sides of the battery module but also between two adjacent rows of single cells arranged. More preferably, a heat transfer path is established between the side of the battery module 800, the heat-conducting material 700, and the hot-end heat spreader 600, and heat is conducted to the outside through the heat-conducting material 700 and the hot-end heat spreader 600; a heat-conducting pad 900 is also provided at the bottom of the battery module 800 to conduct a part of the heat to the box body 100. The thickness of the hot-end heat spreader 600 is 2 to 5 mm, the length is 2 to 5 mm higher than that of the battery module 800, and the height is 2 to 5 mm less than that of the cell 201.

[0026] The thickness of the hot-end heat spreader in this example is 3 mm. In other embodiments, it can also be any number within the range of 2 to 5 mm, such as 2 mm, 5 mm, 4 mm, etc.

[0027] Furthermore, the modular energy storage module with internal heat equalization and external heat dissipation further includes a box body 100, a hot-end heat spreader 600, an air outlet pipe 1000, a cold-end heat dissipation plate 1100, a liquid outlet pipe 200, a liquid collector 400, and a serpentine pipe 500.

[0028] The hot-end heat pipe 600, the outlet pipe 1000, the cold-end heat dissipation plate 1100, the liquid outlet pipe 200, the liquid collector 400 and the serpentine pipe 500 form a complete heat pipe heat dissipation loop, and the loop is filled with the refrigerant 300. The hot-end heat pipe 600 absorbs heat from the battery module 800 through the heat conduction material 700. The liquid refrigerant inside the hot-end heat pipe 600 absorbs heat and evaporates. The gaseous refrigerant enters the cold-end heat dissipation plate through the outlet pipe and is cooled and liquefied by the external cooling device. The liquefied refrigerant collects in the liquid collector 400. When the liquid level of the refrigerant exceeds a certain value of the liquid level of the serpentine pipe 500, siphon drainage occurs, and the liquid refrigerant 300 quickly returns to the hot-end heat pipe 600 again. Since the phase change heat absorption of the refrigerant 300 is large and the phase change temperature fluctuation is small, by repeating this cycle, the heat generated at various parts of the battery module 800 can be quickly transferred to the outside world, and the temperature at various parts of the battery module 800 can be ensured to be uniform. In addition, the liquid refrigerant 300 retained in the serpentine pipe 500 can play a sealing function to prevent the gaseous refrigerant 300 from flowing back.

[0029] The hot-end heat pipe 600 is internally provided with a flow channel, which is composed of a liquid distribution cavity 601, a liquid distribution branch 602, a U-shaped refrigerant heat absorption phase change pool 603, an air outlet branch 604 and a gas collection cavity 605, as Figure 2 shown. The inlet of the liquid distribution cavity 601 is connected to the serpentine pipe 500 and receives the liquid refrigerant 300 from the liquid collector 400, and the outlet is connected to a plurality of liquid distribution branches 602; a plurality of U-shaped refrigerant heat absorption phase change pools are provided on the horizontal section of each liquid distribution branch 602; the lower port of the U-shaped refrigerant heat absorption phase change pool 603 is connected to the liquid distribution branch 602, and the upper port is connected to the vertically distributed air outlet branch 604, and each air outlet branch 604 is connected to the lower end of the gas collection cavity 605; the outlet of the gas collection cavity 605 is connected to the external outlet pipe 1000 to discharge the gaseous refrigerant 300 to the outside.

[0030] The external liquid refrigerant 300 flows from the liquid collector 400 into the liquid distribution cavity 601, and then flows into each U-shaped refrigerant heat absorption phase change pool 603 through the liquid distribution branch 602; the liquid refrigerant absorbs heat from the battery module 800 in the U-shaped refrigerant heat absorption phase change pool 603 and undergoes a phase change from liquid to gas; the gaseous refrigerant 300 passes through the air outlet branch 604, collects in the gas collection cavity 605, and finally is discharged through the outlet pipe 1000.

[0031] The U-shaped refrigerant heat absorption phase change pool 603 is evenly distributed throughout the hot end temperature absorbing plate 600. More preferably, the central axis of the U-shaped U-shaped refrigerant heat absorption phase change pool 603 coincides with the central axis of the single battery cell, further improving the temperature uniformity of the temperature absorbing plate. The amount of heat absorption and evaporation of the liquid refrigerant 300 in each U-shaped refrigerant heat absorption phase change pool 603 is mainly related to the temperature of the corresponding point. At high temperatures, the heat absorption is large, the evaporation is fast, and the temperature drops quickly. At low temperatures, the heat absorption is small, the evaporation is slow, and the temperature drops slowly. Moreover, the temperature fluctuation of the refrigerant 300 heat absorption phase change is small, thereby ensuring that the temperature of the entire hot end temperature absorbing plate 600 and the battery module 800 is uniform. In addition, the amount of liquid refrigerant 300 that can be stored in each U-shaped refrigerant heat absorption phase change pool 603 is the same, so that the liquid refrigerant flowing in from the liquid separation branch 602 can be evenly distributed to each U-shaped branch.

[0032] As time goes by, the refrigerant may gradually become ineffective. To solve this problem, the refrigerant in the modular energy storage module with internal temperature uniformity and external heat dissipation in the present invention can be replaced or replenished. A valve is provided at the outlet of the liquid collector 400. The liquid collector 400 is also provided with a drain port and a liquid filling port. The end of the serpentine tube 500 near the hot end temperature uniformity plate is provided with a power source. When the refrigerant needs to be replaced, the valve at the outlet of the liquid collector 400 is closed and the drain port is opened. Turning on the power source gives the refrigerant a force so that all the refrigerant flows to the liquid collector and then flows out from the drain port. When refrigerant needs to be added, the liquid filling port is opened to replenish the refrigerant.

[0033] The cold end heat sink 1100 is provided with an inner flow channel 1101 and an outer flow channel 1102. Figure 3 As shown. The inner flow channel 1101 is arranged in an oblique grid, which is convenient for evenly distributing and cooling the gas-phase refrigerant 300. The outer flow channel and the inner flow channel both have a certain slope α, and the outer flow channel and the inner flow channel are parallel. Preferably, tanα≈height (H) / width (L). When the value of α is closer to satisfying tanα=H / L, it can ensure that the outer flow channel and the inner flow channel can maintain a certain inclination while having the largest contact area, so as to facilitate the rapid outflow of condensed refrigerant droplets, avoid the droplets from hindering the heat exchange between the gas-phase refrigerant and the flow channel wall, and achieve the highest heat exchange efficiency; the outer flow channel 1102 is also arranged in an oblique grid, which is convenient for increasing the contact area between the inner flow channel and the outer flow channel. The flow direction of the outer flow channel is opposite to that of the inner flow channel 1101, forming a countercurrent heat exchange with the inner flow channel 1102, with high heat exchange efficiency and good temperature uniformity.

[0034] In this embodiment, the liquid outlet pipe 200 , the liquid collector 400 , the serpentine pipe 500 , the hot end temperature equalizing plate 600 , the thermal conductive material 700 , the battery module 800 , the thermal insulation pad 890 and the air outlet pipe 1000 are arranged inside the box 100 .

[0035] The hot-end heat pipe 600 in this embodiment is a blown plate. In an alternative embodiment, the hot-end heat pipe 600 can also be any one of a buried-tube cold plate, a vacuum brazed cold plate, a friction stir welded cold plate, and a cavity cold plate.

[0036] The cold-end heat sink 1100 in this embodiment is a blown plate. In an alternative embodiment, the cold-end heat sink 1100 can also be one of a buried-tube cold plate, a vacuum brazed cold plate, a friction stir welded cold plate, a cavity cold plate, etc. The thickness of the cold-end heat sink 1100 in this embodiment is 3 mm. In other embodiments, it can also be any number within the range of 2 - 5 mm, such as 2 mm, 5 mm, 4 mm, etc. The width of the cold-end heat sink in this embodiment is 3 mm wider than the battery module 800. In other embodiments, it can also be any number within the range of 2 - 5 mm, such as 2 mm, 5 mm, 4 mm, etc. The height of the cold-end heat sink in this embodiment is 3 mm less than the battery module 800. In other embodiments, it can also be any number within the range of 2 - 5 mm, such as 2 mm, 5 mm, 4 mm, etc.

[0037] In an alternative embodiment, the battery module 200 can be any one of a lithium-ion battery module, a lead-acid battery module, a nickel-metal hydride battery module, a supercapacitor module, and a fuel cell module, etc.

[0038] The refrigerant 300 in this embodiment is perfluoromethylcyclohexanone. In an alternative embodiment, the refrigerant 300 can also be one or a combination of more than one of R134a, R245fa, R402A, R404A, R405A, R407C, heptafluoropropane, perfluoromethylcyclohexanone, acetone, ethanol, methanol, etc. The cooling medium is an insulating and volatile medium under normal pressure, which will not cause leakage and short-circuit problems and avoids the condensate problem of water cooling. On the other hand, the external cooling device can take away the heat generated by the battery module only through the cold-end heat sink of the energy storage module, without introducing cooling media such as air, water, ethylene glycol aqueous solution, or refrigerant into the energy storage module. In this way, the energy storage module can become a closed and independent module, and external air is not easy to enter the module, avoiding the dust accumulation problem of air cooling. In a large-scale energy storage system, this modular energy storage module provided by the present invention can be quickly connected and separated from external cooling devices, electrical circuits, etc. in units of modules, and the maintenance and installation are very convenient.

[0039] In an alternative embodiment, the external cooling device 1200 can be one or more of an air conditioner, a vapor compression refrigeration unit, an absorption refrigeration unit, an adsorption refrigeration unit, an ejector refrigeration unit, and a carbon dioxide refrigeration unit.

[0040] In an alternative embodiment, the thermal conductive material 700 can be one or a combination of more than one of thermal conductive potting compound, thermal conductive gasket, thermal conductive silicone grease, and thermal conductive gel.

[0041] In an alternative embodiment, the thermal pad 900 is one or a combination of a thermally conductive potting compound, a thermally conductive gasket, a thermally conductive silicone grease, and a thermally conductive gel.

[0042] In an alternative embodiment, a plurality of temperature alarm points are evenly provided on the hot end heat pipe. When the temperature exceeds a certain threshold, an alarm is triggered, which can be used to monitor the temperature change of the battery module in real time and increase safety.

[0043] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the invention.

[0044] Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. An energy storage module with uniform internal temperature and external heat dissipation, including a battery module, characterized in that, The energy storage module with internal temperature uniformity and external heat dissipation includes: An internal circulation system, including a hot-end temperature equalizing plate covering at least one side of the battery module to absorb and equalize the heat of the battery module. An external circulation system, including a cooling device. The external circulation system is arranged on one side of the internal circulation system to absorb the heat absorbed by the internal circulation system from the battery module and dissipate it through the cooling device. The energy storage module with internal temperature uniformity and external heat dissipation further includes a cold-end heat dissipation plate. The external circulation system is arranged on one side of the internal circulation system, and the external circulation system and the internal circulation system are connected through the cold-end heat dissipation plate. The internal circulation system includes an inner flow channel, and the external circulation system includes an outer flow channel. Both the inner flow channel and the outer flow channel are arranged inside the cold-end heat dissipation plate, and both the inner flow channel and the outer flow channel are arranged in an inclined grid pattern. Both the inner flow channel and the outer flow channel are inclined. The internal circulation system further includes an outlet pipe, a liquid outlet pipe, a liquid collector, and a serpentine pipe. The inlet of the liquid collector is communicated with the inner flow channel of the cold-end heat dissipation plate through the liquid outlet pipe, and the outlet of the liquid collector is communicated with the hot-end temperature equalizing plate through the serpentine pipe. The hot-end temperature equalizing plate absorbs heat from the battery module through a heat-conducting material. The liquid refrigerant inside the hot-end temperature equalizing plate absorbs heat and evaporates. The gaseous refrigerant enters the cold-end heat dissipation plate through the outlet pipe, is cooled and liquefied by the external cooling device. The liquefied refrigerant is collected in the liquid collector. When the liquid level of the refrigerant exceeds a certain value of the liquid level of the serpentine pipe, siphon drainage occurs, and the liquid refrigerant returns to the hot-end temperature equalizing plate again. Among them, the liquid refrigerant remaining in the serpentine pipe can play a sealing function to prevent the gas-phase refrigerant from flowing back. Among them, at least one flow channel is provided inside the hot-end temperature equalizing plate. Each flow channel includes a liquid distribution cavity, at least one liquid distribution branch, a plurality of U-shaped refrigerant heat absorption phase change pools, an air outlet branch, and a gas collection cavity. The inlet of the liquid distribution cavity is connected to the serpentine pipe to receive the liquid refrigerant from the liquid collector, and the outlet of the liquid distribution cavity is connected to each liquid distribution branch. A plurality of U-shaped refrigerant heat absorption phase change pools are provided on the horizontal section of each liquid distribution branch. The low-position port of the U-shaped refrigerant heat absorption phase change pool is connected to the liquid distribution branch, and the high-position port is connected to one of the air outlet branches. Each air outlet branch and the gas collection cavity are connected and communicated. The outlet of the gas collection cavity is connected to the external outlet pipe to discharge the gas-phase refrigerant outward.

2. The energy storage module with uniform internal temperature and external heat dissipation according to claim 1, characterized in that The air outlet branch and the liquid distribution branch are arranged perpendicular to each other.

3. The energy storage module with uniform internal temperature and external heat dissipation according to claim 1, characterized in that, The battery module is composed of a single row of multiple single-cell batteries arranged. The central axis of the U shape of the U-shaped refrigerant heat absorption phase change pool coincides with the central axis of the single-cell battery.

4. The energy storage module with uniform internal temperature and external heat dissipation according to claim 3, characterized in that, The single-cell batteries are combined in multiple rows. The hot-end temperature equalizing plate is also arranged between two adjacent rows of the arranged single-cell batteries. The side of the battery module establishes a heat transfer path with the hot-end temperature equalizing plate through a heat-conducting material, and conducts heat to the outside through the heat-conducting material and the hot-end temperature equalizing plate. A heat-conducting pad is also provided at the bottom of the battery module.

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