An immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe

Abstract

An immersion liquid cooling energy storage power station heat management system combining inverse opal structure surface and biomimetic heat pipe relates to the technical field of immersion liquid cooling of energy storage power station, the cooling liquid flows in the direction perpendicular to the surface of the heat conduction layer as a whole, flows in the direction parallel to the surface of the heat conduction layer and quickly sweeps the surface of the battery monomer locally, and carries out convection heat exchange with the battery monomer, absorbs a large amount of heat and reduces the temperature of the battery. At the same time of immersion liquid cooling, the evaporation end of the loop heat pipe between the adjacent battery monomers directly contacts the surface of the battery monomer to absorb heat, and carries out heat exchange with the cooling liquid flowing in the liquid cooling box, so that the two cooling modes are coupled to greatly improve the overall cooling efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of submerged liquid cooling of energy storage power stations, in particular to a submerged liquid cooling energy storage power station thermal management system combining inverse opal structure surfaces and biomimetic heat pipes. BACKGROUND

[0002] Energy storage power stations are equivalent to urban "power banks", which use renewable energy such as wind and solar energy to generate electricity, and convert excess electricity into chemical energy and store it in energy storage batteries during off-peak electricity consumption. At peak electricity consumption, the chemical energy stored in the energy storage battery is converted into electricity for discharge to participate in peak shaving and frequency modulation, playing a role in peak shaving and valley filling.

[0003] However, lithium-ion batteries have strict requirements for operating temperature. Overly high or low temperatures can significantly reduce the operating performance of lithium-ion batteries and even cause safety problems. In energy storage power stations, large-scale battery energy storage systems have higher battery array density and complex operating conditions. If the heat dissipation problem cannot be effectively solved, the efficiency of the battery system will be severely affected, and in extreme cases, it may even cause battery cell thermal runaway, battery system fire and explosion, and other safety accidents. Therefore, effective thermal management technology is an important guarantee for ensuring the safe and efficient operation of the energy storage battery system.

[0004] Current energy storage power stations mostly use air cooling and indirect liquid cooling cooling solutions. For air cooling systems, the power generation capacity of the power system will decrease significantly when the wind speed is unstable or the wind is too weak, and the cooling capacity of the air cooling system is insufficient and the safety is not high due to its inherent characteristics. Liquid cooling technology can be divided into indirect liquid cooling technology and direct liquid cooling technology. Direct liquid cooling technology has developed rapidly in recent years, and submerged liquid cooling technology is a typical direct liquid cooling technology. Submerged cooling discards the cold plate, allowing the battery to directly contact the submerged cooling liquid, efficiently, quickly and timely transferring the heat generated by the battery. Compared with indirect cold plate cooling, direct submerged cooling theoretically has smaller thermal resistance, higher cooling efficiency and better temperature uniformity. However, submerged liquid cooling technology has limitations. In extreme conditions such as high-temperature weather or high-intensity operation of the energy storage power station, the cooling effect is insufficient to allow the lithium battery to be in the best working state; in low-temperature harsh environments, the capacity is reduced and the charging and discharging power is limited; and direct contact between the lithium battery and the liquid can easily change the structure and pose a certain safety hazard.

[0005] Two-phase liquid cooling technology mainly uses the phase change principle of the heat transfer medium for heat dissipation. Compared with single-phase flow, two-phase flow can absorb or release a large amount of heat during the phase change process, which makes two-phase flow have higher heat transfer performance. At the same time, due to the existence of the gas-liquid interface, two-phase flow has better mixing effect. However, when the critical heat flux density is reached, a vapor film will be generated on the contact surface of the battery, hindering heat transfer, and thus causing a boiling limit problem.

[0006] In view of the above research status, it is urgent to design an immersion heat management system suitable for energy storage power station to provide better protection for power energy safety and efficient use. SUMMARY

[0007] In order to overcome the above technical deficiencies, the application provides an immersion liquid cooling energy storage power station heat management system combining inverse opal structure surface and biomimetic heat pipe to improve the heat exchange efficiency of immersion liquid cooling.

[0008] The technical scheme adopted by the application to overcome the technical problems is:

[0009] An immersion liquid cooling energy storage power station heat management system combining inverse opal structure surface and biomimetic heat pipe, comprising:

[0010] A liquid cooling plate having a sealed liquid cooling cavity I inside, a liquid cooling box body being fastened to the upper end of the liquid cooling plate, and the liquid cooling box body and the liquid cooling plate forming a sealed liquid cooling cavity II;

[0011] N battery modules fixed on the liquid cooling plate, each battery module being composed of M battery monomers and being fixed by a fixing device;

[0012] The front surface and the rear surface of each two battery monomers are respectively provided with P outwardly protruding topological fins, and the front surface, the rear surface of the battery monomers and the surface of each topological fin are provided with a heat conduction layer, and the outer side end of each heat conduction layer is in contact with the evaporation end of the loop heat pipe;

[0013] The condensation end of each loop heat pipe is embedded in the liquid cooling cavity I of the liquid cooling plate, one end of the condensation end is connected with one end of the corresponding evaporation end through a vapor channel, and the other end of the condensation end is connected with the other end of the corresponding evaporation end through a liquid channel;

[0014] A cooling liquid supply system I is arranged on the liquid cooling plate and used for inputting cooling liquid into the liquid cooling cavity I; and

[0015] A cooling liquid supply system II is arranged on the liquid cooling box body and used for inputting cooling liquid into the liquid cooling cavity II.

[0016] Further, N×M clamping grooves are arranged on the liquid cooling plate, and the bottom of each battery monomer is inserted into the corresponding clamping groove.

[0017] Preferably, N is 2, and the two battery modules are parallel to each other.

[0018] Further, the fixing device is an annular steel band, and the steel band is bundled around the periphery of each battery monomer.

[0019] In order to prevent damage to the battery monomers, end plates are respectively pasted to the left and right ends of each battery module.

[0020] Further, the heat-conducting layer is made of inverse opal structure material.

[0021] Further, the cooling liquid supply system I includes a liquid cooling plate inlet arranged at the left side end of the liquid cooling plate and a liquid cooling plate outlet arranged at the right side end of the liquid cooling plate, the liquid cooling plate inlet and the liquid cooling plate outlet are both in communication with the liquid cooling cavity I, the liquid cooling plate inlet is connected with the outlet end of the cooling liquid pump, and the liquid cooling plate outlet is connected with the inlet end of the cooling liquid pump.

[0022] Further, the cooling liquid supply system II includes an inlet arranged at the front end of the liquid cooling tank and an outlet arranged at the rear end of the liquid cooling tank, the axis of the inlet and the axis of the outlet are perpendicular to the surface of the battery monomer, the inlet is connected with the outlet end of the cooling liquid pump, and the outlet is connected with the inlet end of the cooling liquid pump.

[0023] Further, the number and shape of the topological fins are obtained by COMSOL software to have the highest comprehensive heat exchange coefficient in the cooling liquid flow heat transfer process of the outer surface of the battery monomer, and to have the minimum pressure drop as the optimization target.

[0024] In order to improve the heat exchange efficiency, a plurality of blocking pieces are arranged on the left and right sides of the liquid channel of the loop heat pipe along the axial direction at intervals, the blocking pieces are triangular structures, and the blocking pieces located on the left side of the liquid channel and the blocking pieces located on the right side of the liquid channel are symmetrically arranged in a figure-eight shape.

[0025] The beneficial effects of the present application are:

[0026] (1) The present application takes the battery surface as the design domain, and considers flow loss and heat transfer enhancement for topological optimization, P irregular topological fins are arranged on each side of the battery surface, so that the average temperature of the battery monomer surface after the topological fins is increased is lower than that of the conventional structure when the cooling liquid with the same flow speed passes through. At the same time, through topological optimization, the inlet and outlet pressure drops are reduced, and the pump power consumption is reduced. Therefore, the topological optimization of the battery monomer surface is superior to the conventional battery structure in terms of energy consumption, heat dissipation and other comprehensive performance, and the heat exchange efficiency of the immersion liquid cooling is improved.

[0027] (2) The present application arranges the loop heat pipe between the battery monomers, the evaporation end of the loop heat pipe directly contacts the heat-conducting layer and is assisted by the cooling liquid convection heat exchange, the condensation end of the loop heat pipe is arranged in the bottom liquid cooling plate to reduce the size of the tank, so that the overall layout is compact and efficient, and the curved design can optimize the flow area of the liquid cooling plate. The evaporation end of the heat pipe is arranged away from the liquid cooling plate to improve the temperature uniformity. The system integrates immersion liquid cooling, heat pipe cooling and liquid cooling plate to form a high-efficiency heat management system, forms a cooling system with immersion liquid cooling as the main part, heat pipe and liquid cooling plate as the auxiliary part, and a heating system with liquid cooling plate as the main part and heat pipe as the auxiliary part.

[0028] (3) The condensing end is located below the evaporating end, so that the liquid of the condensing end needs to overcome the gravity to return to the evaporating end. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic diagram of the three-dimensional structure of the present application;

[0030] Figure 2 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0031] Figure 3 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0032] Figure 4 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0033] Figure 5 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0034] Figure 6 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0035] Figure 7 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0036] Figure 8 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0037] Figure 9 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0038] Figure 10 is a schematic diagram of the three-dimensional structure of the evaporating end of the present application;

[0039] In the figure, 1. Liquid cooling box 2. Liquid cooling plate 3. Liquid inlet 4. Liquid outlet 5. Liquid cooling plate inlet 6. Liquid cooling plate outlet 7. Evaporating end 8. Liquid channel 9. Vapor channel 10. Condensing end 11. Topological fin 12. Heat conduction layer 13. Battery monomer 14. End plate 15. Steel belt 16. Blocking piece. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings Figure 1 to the drawings Figure 10 The present application is further described.

[0041] As shown in the drawings Figure 1 , the drawings Figure 2 , the drawings Figure 3 , the drawings Figure 4 , the drawings Figure 6 , the drawings Figure 7As shown, an immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe, comprising: a liquid cooling plate 2 having a sealed liquid cooling cavity I inside, a liquid cooling box body 1 is buckled on the upper end of the liquid cooling plate 2, and the liquid cooling box body 1 and the liquid cooling plate 2 form a sealed liquid cooling cavity II; N battery modules are fixed on the liquid cooling plate 2, each battery module is composed of M battery monomers 13 and is fixed by a fixing device; the front surface and the rear surface of each two battery monomers 13 are respectively provided with P outwardly protruding topological fins 11, the front surface, the rear surface of the battery monomer 13 and the surface of each topological fin 11 are provided with a heat conduction layer 12, and the outer side end of each heat conduction layer 12 is in contact with the evaporation end 7 of the loop heat pipe; the condensation end 10 of each loop heat pipe is embedded in the liquid cooling cavity I of the liquid cooling plate 2, one end of the condensation end 10 is connected with one end of the corresponding evaporation end 7 through a steam passage 9, and the other end is connected with the other end of the corresponding evaporation end 7 through a liquid passage 8; a cooling liquid supply system I is arranged on the liquid cooling plate 2 and used for inputting the cooling liquid into the liquid cooling cavity I; and a cooling liquid supply system II is arranged on the liquid cooling box body 1 and used for inputting the cooling liquid into the liquid cooling cavity II. The cooling liquid is input into the liquid cooling cavity II through the cooling liquid supply system II, flows in a direction locally parallel to the surface of the heat conduction layer 12 and quickly sweeps the surface of the battery monomer 13 in a direction perpendicular to the surface of the heat conduction layer 12 as a whole, performs convective heat exchange with the battery monomer 13, absorbs a large amount of heat and reduces the battery temperature. Meanwhile, while the immersion liquid cooling is performed, the evaporation end 7 of the loop heat pipe between the adjacent battery monomers 13 directly contacts the surface of the battery monomer 13 to absorb heat, simultaneously performs heat exchange with the cooling liquid flowing in the liquid cooling box body 1, the two cooling modes are coupled, and the overall cooling efficiency is greatly improved. After absorbing heat, the evaporation end 7 heats the refrigerant in the loop heat pipe into steam, enters the condensation chamber 17 through the steam passage 9, the cooling liquid is input into the liquid cooling plate 2 through the cooling liquid supply system I and exchanges heat with the condensation end 10 of each loop heat pipe, the refrigerant becomes liquid after being cooled and returns to the evaporation end 7 through the liquid passage 8, and circulation is realized.

[0042] In an embodiment of the present application, the liquid cooling plate 2 is provided with N*M clamping grooves, and the bottom of each battery monomer 13 is inserted into the corresponding clamping groove. In this embodiment, preferably, N is 2, and the two battery modules are parallel to each other.

[0043] In an embodiment of the present application, the fixing device is a ring-shaped steel band 15, and the steel band 15 is bundled around the periphery of each battery monomer 13. The steel band 15 is bundled around the periphery of each battery monomer 13. Each battery monomer 13 is fixed by the steel band 15, and the structure is simple and the installation is convenient.

[0044] In one embodiment of the present invention, end plates 14 are respectively attached to the left and right ends of each battery module. The end plates 14 on the outermost sides of the front and rear ends of the battery module can not only improve the overall rigidity of the entire battery module, but also prevent the steel strip 15 from damaging the battery cells 13 on the outer end when fixing each battery cell 13, thereby further improving the reliability of use.

[0045] As attached Figure 5 As shown, in one embodiment of the present invention, the aforementioned thermally conductive layer is made of an inverse opal structure material. During battery module operation, the front and rear surfaces of the battery cell 13 and the topological ribs 11 have relatively high temperatures, causing the coolant in these areas to boil more intensely. During the coolant boiling process, the porous capillary core of the inverse opal structure material uses capillary force to draw the coolant to the boiling surface. The coolant replenishing the boiling surface drives bubbles to escape vertically from the inverse opal structure material, thereby carrying away a large amount of heat and effectively reducing the temperature of the battery module during operation, forming a beneficial gas-liquid two-phase circulation. This increases the critical heat flux density at the boiling surface and improves the overall heat transfer coefficient of the coolant two-phase flow across the battery surface. Simultaneously, the combination of the inverse opal structure and the topological ribs enhances the mixing characteristics of the gas-liquid two-phase fluid on the battery surface, thereby enhancing the uniformity of the coolant flow field and temperature field distribution near the battery surface, ultimately improving the flow and heat transfer characteristics of the battery module.

[0046] In one embodiment of the present invention, the coolant supply system I includes a liquid cooling plate inlet 5 located at the left end of the liquid cooling plate 2 and a liquid cooling plate outlet 6 located at the right end. Both the liquid cooling plate inlet 5 and the liquid cooling plate outlet 6 are connected to the liquid cooling chamber I. The liquid cooling plate inlet 5 is connected to the outlet end of the coolant pump, and the liquid cooling plate outlet 6 is connected to the inlet end of the coolant pump. The coolant pump delivers coolant into the liquid cooling chamber I through the liquid cooling plate inlet 5 to fully exchange heat with the condensing ends 10 of each loop heat pipe. After heat exchange, the coolant flows back to the coolant pump through the liquid cooling plate outlet 6, thus achieving circulation.

[0047] In one embodiment of the present invention, the coolant supply system II includes an inlet 3 located at the front end of the liquid cooling chamber 1 and an outlet 4 located at the rear end of the liquid cooling chamber 1. The axes of the inlet 3 and the outlet 4 are perpendicular to the surface of the battery cell 13. The inlet 3 is connected to the outlet end of the coolant pump, and the outlet 4 is connected to the inlet end of the coolant pump. The coolant pump delivers coolant into the liquid cooling chamber II of the liquid cooling chamber 1 through the inlet 3. Since the axis of the inlet 3 is perpendicular to the surface of the battery cell 13, the coolant impacts the surface of the battery cell 13, achieving sufficient heat exchange with the battery cell 13. After heat exchange, the coolant flows back to the coolant pump through the outlet 4, realizing circulation.

[0048] In one embodiment of the present invention, the number and shape of the topological ribs 11 are obtained by topological optimization of the battery surface ribs using COMSOL software, with the goal of achieving the highest overall heat transfer coefficient during the coolant flow heat transfer process across the surface of the battery cell 13 and minimizing pressure drop. (See attached...) Figure 9 As shown, by comparing with the surface structures of circular and square staggered batteries, it is found that the average surface temperature of the battery cell 13 of the present invention decreases with the increase of the initial fluid velocity, and the surface temperature of the battery with the topological fins 11 is always lower than that of the circular and square staggered battery structures, indicating that the heat dissipation performance of the topological fin structure 11 is better than that of the traditional structure. (See attached diagram) Figure 10 As shown, the average surface temperature of the battery of the three types decreases with the increase of pump power. When the same temperature is reached, the topological rib 11 structure of the present invention consumes less pump power than the other two structures, indicating that the structure of the topological rib 11 is superior to the traditional structure in terms of energy consumption.

[0049] As attached Figure 8 As shown, in one embodiment of the present invention, several baffles 16 are arranged axially at intervals on the left and right sides of the liquid channel 8 of the loop heat pipe. The baffles 16 have a triangular structure, and the baffles 16 on the left side of the liquid channel 8 and the baffles 16 on the right side of the liquid channel 8 are arranged symmetrically in a figure-eight shape. The baffles 16 on the left and right sides of the liquid channel 8 are designed to form a biomimetic succulent capillary structure. Based on its advantages in directional fluid transport, the biomimetic succulent capillary structure arranges a unique asymmetrical folding structure on the wall of the liquid channel 8, resulting in a difference in the liquid meniscus in two opposite directions. This, in conjunction with the capillary force, causes the liquid to flow directionally in the direction of anti-gravity. The baffles 16 at the left and right ends are arranged in a figure-eight shape. The angle between the upper end of the baffle 16 and the inner wall of the liquid channel 8 is 57°, and the angle between the lower end of the baffle 16 and the inner wall of the liquid channel 8 is 51°. This asymmetry causes the refrigerant to twist in two directions, realizing the directional transport of the liquid refrigerant in the direction of anti-gravity, and providing power for the flow of the refrigerant.

[0050] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe, characterized in that, The application relates to a liquid-cooled battery module. The application comprises: a liquid-cooled plate (2) with a sealed liquid-cooled cavity I inside, a liquid-cooled box body (1) being fastened to the upper end of the liquid-cooled plate (2), and the liquid-cooled box body (1) and the liquid-cooled plate (2) forming a sealed liquid-cooled cavity II; N battery modules fixed on the liquid-cooled plate (2), each battery module being composed of M battery monomers (13) and being fixed by a fixing device; the front surface and the rear surface of each two battery monomers (13) being respectively provided with P outwardly protruding topological fins (11), the front surface and the rear surface of the battery monomers (13) and the surfaces of the topological fins (11) being provided with heat-conducting layers (12), and the outer side end of each heat-conducting layer (12) being in contact with the evaporation end (7) of a loop heat pipe; the condensation end (10) of each loop heat pipe being embedded in the liquid-cooled cavity I of the liquid-cooled plate (2), one end of the condensation end (10) being connected with one end of the corresponding evaporation end (7) through a steam passage (9), and the other end of the condensation end (10) being connected with the other end of the corresponding evaporation end (7) through a liquid passage (8); a cooling liquid supply system I arranged on the liquid-cooled plate (2) and used for inputting cooling liquid into the liquid-cooled cavity I; and a cooling liquid supply system II arranged on the liquid-cooled box body (1) and used for inputting cooling liquid into the liquid-cooled cavity II. The heat-conducting layers are made of inverse opal structure materials. The number and shape of the topological fins (11) are obtained by COMSOL software through topological optimization of the battery surface fins in the process of cooling liquid flowing outside the battery monomer (13) surface heat transfer with the highest comprehensive heat exchange coefficient and the minimum pressure drop as the optimization target.

2. The immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe according to claim 1, characterized in that: N* M clamping grooves are arranged on the liquid-cooled plate (2), and the bottom of each battery monomer (13) is inserted into the corresponding clamping groove.

3. The immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe of claim 1, wherein: N is 2, and the two battery modules are parallel to each other.

4. The immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe of claim 1, wherein: The fixing device is a ring-shaped steel belt (15) which is bound around the periphery of each battery monomer (13).

5. The immersion liquid cooling energy storage power station thermal management system combining inverse opal structure surface and biomimetic heat pipe of claim 4, wherein: End plates (14) are respectively pasted on the left and right ends of each battery module.

6. The immersion liquid cooling energy storage plant thermal management system incorporating inverse opal structure surface and biomimetic heat pipe of claim 1, wherein: The cooling liquid supply system I comprises a liquid-cooled plate inlet (5) arranged on the left end of the liquid-cooled plate (2) and a liquid-cooled plate outlet (6) arranged on the right end of the liquid-cooled plate (2), the liquid-cooled plate inlet (5) and the liquid-cooled plate outlet (6) are both in communication with the liquid-cooled cavity I, the liquid-cooled plate inlet (5) is connected with the outlet end of a cooling liquid pump, and the liquid-cooled plate outlet (6) is connected with the inlet end of the cooling liquid pump.

7. The immersion liquid cooling energy storage plant thermal management system incorporating inverse opal structure surface and biomimetic heat pipe of claim 1, wherein: The cooling liquid supply system II comprises an inlet (3) arranged on the front end of the liquid-cooled box body (1) and an outlet (4) arranged on the rear end of the liquid-cooled box body (1), the axis of the inlet (3) and the axis of the outlet (4) are perpendicular to the surface of the battery monomer (13), the inlet (3) is connected with the outlet end of the cooling liquid pump, and the outlet (4) is connected with the inlet end of the cooling liquid pump.

8. The immersion liquid cooling energy storage plant thermal management system incorporating inverse opal structure surface and biomimetic heat pipe of claim 1, wherein: A plurality of blocking pieces (16) are arranged on the left and right sides of the liquid passage (8) of the loop heat pipe along the axial direction, the blocking pieces (16) are in triangular structure, the blocking piece (16) on the left side of the liquid passage (8) and the blocking piece (16) on the right side of the liquid passage (8) are symmetrically arranged in an eight-shaped manner.

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