Spray pipe type loop heat pipe cold plate and energy storage battery thermal management system

Abstract

The invention discloses a spray pipe type loop heat pipe cold plate and an energy storage battery heat management system, the spray pipe type loop heat pipe cold plate comprises a cold plate main body and a first heat exchanger, the cold plate main body is provided with a plate-shaped hollow cavity, and a cold plate air outlet and a cold plate liquid inlet which are respectively arranged at the upper end and the lower end of the cold plate main body and are communicated with the hollow cavity; vertical air guide partition plates are fixed in the hollow cavity, an evaporation channel is formed between every two horizontally adjacent air guide partition plates, and each evaporation channel is filled with a liquid absorption core. A compensation chamber is formed between the lower end of the air guide partition plate and the bottom face of the cold plate body, a pressure equalizing cavity is formed between the upper end of the air guide partition plate and the top face of the cold plate body, the cold plate air outlet is located in the center line of the top end of the pressure equalizing cavity, and the height of the pressure equalizing cavity is gradually reduced from the cold plate air outlet to the two sides. A micro spray pipe structure is additionally arranged on the cold plate on the basis of a loop heat pipe, the flowing speed of a gaseous working medium can be effectively increased, the heat exchange efficiency is improved, and therefore the high-speed heat dissipation requirement of an energy storage battery heat management system is met.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage battery thermal management, and specifically to a spray tube loop heat pipe cold plate and an energy storage battery thermal management system. Background Art

[0002] The energy storage battery thermal management system is a crucial part of the energy storage system. Its main purpose is to maintain the working temperature of the battery within the optimal range to optimize performance, extend the battery life, and ensure safety.

[0003] In the traditional energy storage power station battery thermal management system, the mainstream cooling method in the market is liquid cooling. The liquid cooling-based energy storage power station thermal management system has complex pipelines, high maintenance difficulty, a large space occupied by the liquid circulation system, higher requirements for the layout design of the energy storage power station, and a risk of internal coolant leakage.

[0004] A loop heat pipe (LHP) refers to a closed-loop heat pipe. Generally, it consists of an evaporator, a condenser, a liquid reservoir, and vapor and liquid pipelines. Its working principle is as follows: Applying a heat load to the evaporator, the working fluid evaporates on the outer surface of the capillary wick of the evaporator. The generated vapor flows out from the vapor channel into the vapor pipeline, and then enters the condenser to condense into a liquid and subcool. The reflux liquid enters the liquid main pipeline through the liquid pipeline to supply the capillary wick of the evaporator. Such a cycle is driven by the capillary pressure generated by the capillary wick of the evaporator without an external power source.

[0005] The cold plate using the loop heat pipe principle can be used for thermal management. However, due to the large energy density of the batteries in the energy storage power station, high-density heat is generated under battery operating conditions. The heat transfer efficiency of the conventional cold plate is limited and it is difficult to meet the requirements. Summary of the Invention

[0006] The purpose of the present invention is to provide a spray tube loop heat pipe cold plate and an energy storage battery thermal management system. The cold plate adds a micro spray tube structure on the basis of the loop heat pipe, which can effectively improve the heat transfer speed, thereby meeting the high-speed heat dissipation requirements of the energy storage battery thermal management system.

[0007] The technical solution adopted by the present invention is: A spray tube loop heat pipe cold plate includes a cold plate main body and a first heat exchanger. The cold plate main body has a plate-shaped hollow chamber, a cold plate air outlet and a cold plate liquid inlet that are located at the upper and lower ends of the cold plate main body respectively and communicate with the hollow chamber. A vertical air guide partition is fixed in the hollow chamber, and evaporation channels are formed between horizontally adjacent air guide partitions. The evaporation channels are filled with a wick. A compensation chamber is formed between the lower end of the air guiding partition plate and the bottom surface of the cold plate body, and a pressure equalizing chamber is formed between the upper end of the air guiding partition plate and the top surface of the cold plate body. The cold plate air outlet is located on the center line at the top end of the pressure equalizing chamber. The height of the pressure equalizing chamber gradually decreases from the cold plate air outlet to both sides, so that a low pressure area is formed at the center of the pressure equalizing chamber; Wherein: the air guiding partition plate is composed of air guiding columns arranged along the height direction. A micro nozzle structure is formed between adjacent air guiding columns on the same air guiding partition plate, and the micro nozzle structure is inclined towards the center of the pressure equalizing chamber.

[0008] As a preferred solution, the micro nozzle structure includes a converging section, a throat, and a diverging section. The diverging section is located on the side close to the cold plate air outlet in the horizontal direction, and the midpoint position of the outlet end of the diverging section is higher than the midpoint position of the inlet end of the converging section.

[0009] As a preferred solution, the air guiding partition plates are divided into two groups, and the two groups of air guiding partition plates are symmetrically arranged on the left and right along the center line of the hollow chamber.

[0010] As a preferred solution, the evaporation channel includes a main channel located between the two groups of air guiding partition plates and auxiliary channels located between the air guiding partition plates in the same group. The main channel is directly below the cold plate air outlet, and the horizontal width of the main channel is greater than the horizontal width of the auxiliary channels.

[0011] As a preferred solution, all the air guiding partition plates are of the same height.

[0012] As a preferred solution, the wick is a carbon fiber capillary wick.

[0013] An energy storage battery thermal management system includes a front-end heat exchange cycle, an intermediate heat exchange cycle, and a terminal battery heat exchange cycle that are adjacent to each other in sequence. The terminal battery heat exchange cycle is installed in the gaps of the battery pack, and heat can be exchanged between adjacent cycles; it also includes a temperature sensor for measuring the temperature of the battery pack and a system controller; The terminal battery heat exchange cycle includes a nozzle type loop heat pipe cold plate. The cold plate air outlet and the cold plate liquid inlet of the nozzle type loop heat pipe cold plate are connected to the hot fluid pipeline of the first heat exchanger to form a circulation pipeline; The cold fluid pipeline of the first heat exchanger is connected in series in the intermediate heat exchange cycle.

[0014] As a preferred solution, the first heat exchanger is a shell and tube heat exchanger, and the first heat exchanger is attached to the cold plate body of the nozzle type loop heat pipe cold plate.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. For the nozzle type loop heat pipe cold plate of the present invention, micro nozzle structures are arranged on both sides of the wick, which can accelerate the flow rate of the gaseous working medium in the wick, thereby improving the heat exchange efficiency; 2. The spray tube loop heat pipe cold plate of the present invention forms a low-pressure area at the center of the pressure equalizing chamber, which is beneficial to increasing the pressure difference on both sides of the micro spray tube structure, and further improving the evaporation rate of the working fluid in the wick. 3. The spray tube loop heat pipe cold plate of the present invention has the micro spray tube structure inclined towards the low-pressure area at the center of the pressure equalizing chamber, which is beneficial to the smooth transfer of the working fluid vapor and reduces the resistance. 4. The energy storage battery thermal management system of the present invention adopts a three-working fluid coupling method. Compared with the traditional liquid-cooled energy storage power station thermal management system, it not only shows excellent temperature uniformity and fast response ability in battery cooling, but also can effectively prevent the internal coolant from causing short circuit and fire of the energy storage battery when the cold plate is damaged and leaked, improving the safety of the operation of the energy storage power station. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the end battery heat exchange cycle of the present invention; Figure 2 It is a schematic cross-sectional view of the spray tube loop heat pipe cold plate of the present invention; Figure 3 It is an external schematic diagram of the spray tube loop heat pipe cold plate of the present invention; Figure 4 It is a schematic diagram of the air guide column of the present invention; Figure 5 It is a schematic diagram of the micro spray tube structure on the right side group air guide partition of the present invention; Figure 6 It is a schematic diagram of the wick of the present invention; Figure 7 It is an overall schematic diagram of the first heat exchanger of the present invention; Figure 8 It is a schematic cross-sectional view of the first heat exchanger of the present invention; Figure 9 It is a schematic diagram of the energy storage battery thermal management system of the present invention.

[0018] Reference Signs: 1. Variable frequency compressor, 2. Condenser, 3. Electronic expansion valve, 4. Gas-liquid separator, 5. Second heat exchanger, 6. Manifold, 7. Jet-type loop heat pipe cold plate, 8. Circulating water pump, 9. Temperature sensor, 10. Liquid return pipe, 11. First heat exchanger, 12. Cold plate body, 13. Mounting hole, 14. Cold plate liquid inlet, 15. Gas guiding column, 16. Pressure equalizing chamber, 17. Cold plate gas outlet, 18. Evaporation channel, 181. Main channel, 182. Auxiliary channel, 19. Liquid absorption core, 20. Compensation chamber, 21. Converging section, 22. Throat, 23. Diverging section. Detailed implementation manners

[0019] Next, the present invention will be specifically described through exemplary implementation manners. However, it should be understood that without further elaboration, the elements, structures, and features in one implementation manner can also be beneficially combined with those in other implementation manners.

[0020] It should be noted that: Unless otherwise defined, the technical terms or scientific terms used herein should have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The words such as "a", "an", or "the" used in the specification and claims of this patent application for the invention do not express a limitation on quantity, but rather indicate the existence of at least one; the "first", "second", and "third" used herein should not be regarded as a limitation on the order of components, but are only used to distinguish different components; words such as "comprising" or "including" indicate that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same functions.

[0021] For a clearer description of the specific structural composition of the jet-type loop heat pipe cold plate and the energy storage battery thermal management system, the following Figures 1-9 describes this embodiment: As Figures 1-6As shown in the figure, a nozzle-type loop heat pipe cold plate 7 includes a cold plate body 12 and a first heat exchanger 11. The cold plate body 12 has a plate-shaped hollow chamber, and a cold plate gas outlet 17 and a cold plate liquid inlet 14 are respectively located at the upper and lower ends of the cold plate body 12 and communicate with the hollow chamber. A vertical gas guiding partition is fixed in the hollow chamber, and evaporation channels 18 are formed between horizontally adjacent gas guiding partitions. A wick 19 is filled in the evaporation channels 18. A compensation chamber 20 is formed between the lower end of the gas guiding partition and the bottom surface of the cold plate body 12, and a pressure equalizing chamber 16 is formed between the upper end of the gas guiding partition and the top surface of the cold plate body 12. The cold plate gas outlet 17 is located on the center line at the top end of the pressure equalizing chamber 16. The height of the pressure equalizing chamber 16 gradually decreases from the cold plate gas outlet 17 to both sides, so that a low-pressure area is formed at the center of the pressure equalizing chamber 16. Among them: the gas guiding partition is composed of gas guiding columns 15 arranged along the height direction, and a micro-nozzle structure is formed between adjacent gas guiding columns 15 on the same gas guiding partition, and the micro-nozzle structure is inclined towards the center of the pressure equalizing chamber 16.

[0022] During the use process, the heat of the battery pack is transferred to the nozzle-type loop heat pipe cold plate 7. The cooled working fluid liquid is inhaled into the compensation chamber 20 through the cold plate liquid inlet 14. The wick 19 inhales the working fluid liquid, absorbs heat and heats the wick 19, so that the working fluid liquid evaporates on its surface. The high-temperature working fluid vapor mainly transfers upward through the evaporation channels 18 and is then discharged through the cold plate gas outlet 17. Since the pressure at the central part of the pressure equalizing chamber 16 and the hollow chamber is low and the pressure on both sides is high, part of the working fluid vapor passes through the micro-nozzle structure and transfers laterally to the central part of the hollow chamber to be discharged from the cold plate gas outlet 17 faster. Due to the acceleration effect and the inclined setting mode of the micro-nozzle structure, the high-temperature working fluid vapor can reach the cold plate gas outlet 17 faster and quickly take away the heat received by the cold plate.

[0023] Refer to Figure 2 , the gas guiding partition is used to separate the wick 19, reduce steam turbulence, and at the same time serve as the carrier of the micro-nozzle structure. All the gas guiding partitions can be set at the same height.

[0024] Refer to Figure 6 , the wick 19 is composed of multiple carbon fiber capillary wicks, and different carbon fiber capillary wicks are installed in different evaporation channels 18.

[0025] Refer to Figure 4 and Figure 5 , the micro-nozzle structure includes a converging section 21, a throat 22 and a diverging section 23. The diverging section 23 is located on the side close to the cold plate gas outlet 17 in the horizontal direction, and the midpoint position of the outlet end of the diverging section 23 is higher than the midpoint position of the inlet end of the converging section 21 (in Figure 5In it, the arrow is on the line connecting the two midpoint positions, and the arrow is used to indicate the general running direction of the steam flow); this micro nozzle structure is based on the principle of a convergent-divergent nozzle (Laval nozzle). The convergent section 21 accelerates the steam flow through a gradually decreasing cross-sectional area and reaches the critical velocity at the throat 22 with the minimum cross-sectional area. Subsequently, the divergent section 23 further reduces the gas pressure using the gradually increasing cross-sectional area, enabling the air flow to be further increased after breaking through the acceleration obstacle, and the high-speed working medium steam quickly takes out the heat of the nozzle-type loop heat pipe cold plate 7.

[0026] Refer to Figure 2 , the air guide partition is divided into two groups, and the two groups of air guide partitions are symmetrically arranged on the left and right along the center line of the hollow chamber. Figure 5 The micro nozzle structure shown is located on Figure 2 the air guide partition of the right group in

[0027] Refer to Figure 2 , the evaporation channel 18 includes a main channel 181 located between the two groups of air guide partitions and a secondary channel 182 located between the air guide partitions of the same group. The main channel is directly below the cold plate air outlet 17. Due to the central air flow velocity of the hollow chamber, therefore, the horizontal width of the main channel 181 is greater than the horizontal width of the secondary channel 182, reducing the setting of the air guide partition and increasing the flexibility of the upward transfer of the working medium steam.

[0028] Refer to Figure 3 , the cold plate body can be composed of two shells. Installation holes 13 are reserved on the two shells, and after processing, it can be connected and fixed to the battery box through bolts and the installation holes 13.

[0029] Refer to Figure 9 , an energy storage battery thermal management system includes a front-end heat exchange cycle A, an intermediate heat exchange cycle B, and a terminal battery heat exchange cycle C that are adjacent in sequence. The terminal battery heat exchange cycle C is installed in the gap of the battery pack, and heat interaction can occur between adjacent cycles; it also includes a temperature sensor 9 for measuring the temperature of the battery pack and a system controller; Specifically, for the front-end heat exchange cycle A: The inlet and outlet of the variable-frequency compressor 1 are respectively connected to the gas-liquid separator 4 and the condenser 2 with copper pipes, and the gas-liquid separator 4 is connected to the second heat exchanger 5 (plate heat exchanger) with a copper pipe; the condenser 2, the electronic expansion valve 3, and the plate heat exchanger 5 are connected in sequence using copper pipes; For the intermediate heat exchange cycle B: The second heat exchanger 5, the manifold 6, the first heat exchanger 11, and the circulation water pump 8 form a cycle; the cold fluid pipelines of each first heat exchanger 11 are connected in series in the intermediate heat exchange cycle; End - cell heat - exchange cycle C: It includes a spray - type loop heat pipe cold plate 7. Among them, the cold - plate air outlet 17 and the cold - plate liquid inlet 14 of the spray - type loop heat pipe cold plate 7 are connected to both ends (the air - intake side and the liquid - return side) of the hot - fluid pipeline of the first heat exchanger 11 to form a circulation pipeline; the pipe height of the air - intake side of the hot - fluid pipeline is slightly higher than that of the liquid - outlet side to facilitate liquid return. The energy - storage battery has multiple battery boxes. Each battery box is provided with at least one set of spray - type loop heat pipe cold plates 7 and first heat exchangers 11. The cold - fluid pipelines of the first heat exchangers 11 of different groups of battery boxes are connected in parallel in the intermediate heat - exchange cycle B. The first heat exchanger 11 is a conventional double - pipe heat exchanger. The first heat exchanger 11 is attached to the cold - plate body 12 of the spray - type loop heat pipe cold plate 7, and this design saves space; the liquid - return side of the hot - fluid pipeline of the first heat exchanger 11 is far from the cold - plate liquid inlet 14. Therefore, the liquid - return side and the cold - plate liquid inlet 14 are connected by an adiabatic liquid - return pipeline 10.

[0030] During refrigeration, the working fluid inside the spray - type loop heat pipe cold plate 7 transports the battery heat out, transfers the heat to the intermediate heat - exchange cycle B through the first heat exchanger 11 (double - pipe heat exchanger), and then transfers the heat to the external heat - exchange cycle through a plate heat exchanger for cooling. Compared with the traditional power - station battery thermal - management system, the three - working - fluid coupled energy - storage power - station thermal - management cycle based on the spray - type loop heat pipe cold plate, by reasonably selecting the working fluid inside the spray - type loop heat pipe cold plate, can not only meet the battery heat - dissipation requirements under normal cold - plate operation, but also leak out in the form of gas when the cold plate leaks, without causing short - circuit fires of the energy - storage battery, and greatly improves the safety, increasing the overall safety of the energy - storage power station.

[0031] The parts not detailed in the above embodiments are prior art.

[0032] It should be noted that although the present invention has been described through the above - mentioned embodiments, the present invention can also have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope protected by the appended claims of the present invention and their equivalents.

Claims

1. A nozzle-type loop heat pipe cold plate, characterized in that: It includes a cold plate body (12) and a first heat exchanger (11). The cold plate body (12) has a plate-shaped hollow chamber, and a cold plate air outlet (17) and a cold plate liquid inlet (14) that are located at the upper and lower ends of the cold plate body (12) respectively and communicate with the hollow chamber; a vertical air guiding partition is fixed in the hollow chamber, and evaporation channels (18) are formed between horizontally adjacent air guiding partitions, and a liquid absorbing core (19) is filled in the evaporation channels (18). A compensation chamber (20) is formed between the lower end of the air guiding partition and the bottom surface of the cold plate body (12), and a pressure equalizing chamber (16) is formed between the upper end of the air guiding partition and the top surface of the cold plate body (12). The cold plate air outlet (17) is located on the center line at the top end of the pressure equalizing chamber (16). The height of the pressure equalizing chamber (16) gradually decreases from the cold plate air outlet (17) to both sides, so that a low pressure area is formed at the center of the pressure equalizing chamber (16). Among them: the air guiding partition is composed of air guiding columns (15) arranged along the height direction, and a micro nozzle structure is formed between adjacent air guiding columns (15) on the same air guiding partition, and the micro nozzle structure is inclined towards the center of the pressure equalizing chamber (16).

2. The jet-tube loop heat pipe cold plate according to claim 1, characterized in that: The micro nozzle structure includes a converging section, a throat section and a diverging section. The diverging section is located on the side close to the cold plate air outlet (17) in the horizontal direction, and the midpoint position of the outlet end of the diverging section is higher than the midpoint position of the inlet end of the converging section.

3. The jet-tube loop heat pipe cold plate according to claim 1, characterized in that: The air guiding partitions are divided into two groups, and the two groups of air guiding partitions are symmetrically arranged left and right along the center line of the hollow chamber.

4. The jet-tube loop heat pipe cold plate according to claim 3, characterized in that: The evaporation channels (18) include a main channel between the two groups of air guiding partitions and auxiliary channels between the air guiding partitions in the same group. The main channel is located directly below the cold plate air outlet (17), and the horizontal width of the main channel is greater than the horizontal width of the auxiliary channels.

5. The cold plate of a jet-tube loop heat pipe according to claim 1, wherein: All the air guiding partitions are of the same height.

6. The jet-tube loop heat pipe cold plate according to claim 1, wherein: The liquid absorbing core (19) is a carbon fiber capillary core.

7. A thermal management system for an energy storage battery, characterized in that: It includes a front-end heat exchange cycle, an intermediate heat exchange cycle, and a terminal battery heat exchange cycle that are adjacent in sequence. The terminal battery heat exchange cycle is installed in the gaps of the battery pack, and heat can be exchanged between adjacent cycles; it also includes a temperature sensor (9) for measuring the temperature of the battery pack and a system controller. The terminal battery heat exchange cycle includes the nozzle type loop heat pipe cold plate as described in claim 1. Among them, the cold plate air outlet (17) and the cold plate liquid inlet (14) of the nozzle type loop heat pipe cold plate are connected to the hot fluid pipeline of the first heat exchanger (11) to form a circulation pipeline. The cold fluid pipeline of the first heat exchanger (11) is connected in series in the intermediate heat exchange cycle.

8. The thermal management system for an energy storage battery according to claim 7, characterized in that: The first heat exchanger (11) is a double-pipe heat exchanger, and the first heat exchanger (11) is attached to the cold plate body (12) of the nozzle type loop heat pipe cold plate.

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