Electrochemical energy storage system and thermal management system

Abstract

The invention relates to the technical field of energy storage systems, in particular to an electrochemical energy storage system and a thermal management system.The electrochemical energy storage system comprises battery modules, liquid cooling plates used for cooling the battery modules are arranged below the battery modules, and heat pipe clusters used for cooling the battery modules are arranged between the adjacent battery modules in a clamped mode; the heat pipe cluster comprises a plurality of gravity assisted heat pipes arranged in a stacked manner and a phase change material layer covering the surfaces of the gravity assisted heat pipes, and the phase change material layer is used for absorbing heat generated by the battery module. According to the electrochemical energy storage system provided by the invention, the corresponding heat dissipation parts are respectively arranged at the bottoms of the battery cells and the large side surfaces of the battery cells, so that at least two surfaces of the battery cells are fully cooled, the effect of reducing the temperature difference of the battery cells in the battery module is achieved, the cycle life of the battery cells is prolonged, the overall life of the energy storage system is further prolonged, and the production cost is reduced. In addition, the energy consumption of the heat management system can be reduced to a certain extent, and the energy conversion efficiency of the energy storage system is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to an electrochemical energy storage system and a thermal management system. Background Art

[0002] In electrochemical energy storage systems, thermal management of battery cells is crucial, and overheating of battery cells may affect the performance and life of the energy storage system. The existing mainstream thermal management technology solutions for battery cells use plate-type liquid cooling technology, air cooling technology, or a simple combination of the two. This thermal management technology solution has great limitations. Because the main heating parts of the battery cell are the tabs on the top and the large surface of the battery cell on the side, conventional liquid cooling equipment is set at the bottom of the battery cell, and conventional air cooling is also difficult to provide efficient heat dissipation for the large surface of adjacently arranged battery cells. Therefore, the heat dissipation effect is poor, and it may also cause different batteries in the same battery pack to have a large temperature difference, which in turn leads to the barrel effect and affects the life of the battery cell. Summary of the invention

[0003] The present invention provides an electrochemical energy storage system with good heat dissipation effect, which includes a battery module, a liquid cooling plate for cooling the battery module is arranged below the battery module, a heat pipe cluster for cooling the battery module is sandwiched between adjacent battery modules, the heat pipe cluster includes a plurality of stacked gravity heat pipes and a phase change material layer coated on the surface of the gravity heat pipes, and the phase change material layer is used to absorb the heat generated by the battery module. Furthermore, it comprises an energy storage unit, which comprises a plurality of battery modules arranged side by side, and thermal conductive gel is respectively filled between the battery module and the heat pipe cluster and between the battery module and the liquid cooling plate.

[0004] Furthermore, a heat pipe assembly is provided in the energy storage unit, and the heat pipe assembly includes the heat pipe cluster and a heat dissipation end plate, the heat dissipation end plate is installed above the liquid cooling plate, the heat dissipation end plate is connected to the heat pipe cluster, and the heat pipe cluster extends from the heat dissipation end plate toward one side of the battery module into between the battery modules.

[0005] Furthermore, the gravity heat pipe includes an evaporation section, an insulation section and a condensation section. The evaporation section is connected to the heat dissipation end plate for heat exchange. The insulation section is arranged between the evaporation section and the condensation section and is respectively fixedly connected to the evaporation section and the condensation section as a whole. The condensation section is arranged between adjacent battery modules. The cross-section of the condensation section is an oblong with a longitudinal dimension larger than a transverse dimension. A plurality of microporous channels for circulating cooling medium are arranged in the condensation section.

[0006] Furthermore, the heat pipe assembly also includes a heat pipe bracket, which is arranged above the liquid cooling plate and fixedly connected to the liquid cooling plate as a whole, and the heat pipe bracket is fixedly connected to the gravity heat pipe extending between the battery modules as a whole, and the heat pipe bracket is relatively fixed to the stacked gravity heat pipes respectively to relatively fix the gravity heat pipes into a cluster.

[0007] Furthermore, it also includes an air-cooled water cooling unit, which is connected to the liquid cooling plate and is used to dissipate heat for the cooling medium flowing through the liquid cooling plate.

[0008] Furthermore, it includes a first cabinet body for accommodating the energy storage unit, a plurality of the energy storage units are stacked in the first cabinet body, the first cabinet body is provided with a first air inlet and a first air outlet, the first air inlet and the first air outlet are arranged on a side close to the heat dissipation end plate, and the first air inlet is arranged above the first air outlet.

[0009] Furthermore, it includes a second cabinet for accommodating electrical components, the air-cooled water cooling unit is arranged in the second cabinet, the second cabinet is provided with a second air inlet and a second air outlet, the second air inlet and the second air outlet are respectively arranged on the first side and the second side of the second cabinet, the first side is located in front of the second cabinet, and the second side is located behind the second cabinet.

[0010] Furthermore, the air-cooled water cooling unit is connected to the liquid cooling plate through a pipeline passing through the second cabinet and the first cabinet.

[0011] Furthermore, the present invention also includes a thermal management system, which is used to control the aforementioned electrochemical energy storage system, and the thermal management system is used to control the operation of the liquid cooling plate and the heat pipe cluster.

[0012] The electrochemical energy storage system and thermal management system provided by the present invention provide corresponding heat dissipation components at the bottom of the battery cell and the large side surfaces of the battery cell, so that at least two surfaces of the battery cell are fully cooled, thereby achieving the effect of reducing the temperature difference of each battery cell in the battery module, thereby improving the cycle life of the battery cell and further improving the overall life of the energy storage system. In addition, the energy consumption of the thermal management system can be reduced to a certain extent, further improving the energy conversion efficiency of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of an energy storage unit provided by the present invention.

[0014] Figure 2 It is a cross-sectional view of the energy storage unit in the present invention.

[0015] Figure 3It is a schematic diagram of the liquid cooling plate and heat pipe assembly in the present invention.

[0016] Figure 4 Schematic diagram of the heat pipe assembly of the present invention.

[0017] Figure 5 It is a side view of the heat pipe assembly in the present invention.

[0018] Figure 6 It is a schematic diagram of the shell of the energy storage unit in the present invention.

[0019] Figure 7 It is a cross-sectional view of the heat pipe cluster in the present invention.

[0020] Figure 8 It is a cross-sectional view of the first cabinet and the second cabinet in the present invention.

[0021] Fig. 9 It is a schematic diagram of the first cabinet and the second cabinet in the present invention. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the present invention is described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0023] It should be noted that the terms "first", "second", "third", "fourth", etc. in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0024] See also Figure 1 and Figure 2 The electrochemical energy storage system of the present invention includes an energy storage unit 1, wherein the energy storage unit 1 includes a plurality of battery modules 11 arranged side by side, a liquid cooling plate 2 for cooling the battery modules 11 is arranged below the battery modules 11, and a heat pipe cluster 3 for cooling the battery modules 11 is sandwiched between adjacent battery modules 11. Please refer to Figure 3The heat pipe cluster 3 includes a plurality of stacked gravity heat pipes 31 and a phase change material layer coated on the surface of the gravity heat pipe 31. The phase change material layer is used to absorb and store the heat generated by the battery module 11. The battery module 11 and the heat pipe cluster 3 and the battery module 11 and the liquid cooling plate 2 are respectively filled with thermal conductive gel. Specifically, in this embodiment, the battery cell in the energy storage unit 1 adopts a high-performance lithium iron phosphate system dedicated energy storage battery cell, which can store energy during charging and release energy during discharging. Solid-state batteries, sodium ion batteries and other batteries that can be cycled multiple times can also be used. The battery module 11 is composed of a battery cell, a battery connection system CCS, a collection harness, an aluminum bus, an end plate, a thermal barrier component, a steel belt, a fixing, etc. The shell of the energy storage unit 1 is composed of a current power positive and negative fast plug-in, a communication interface, an explosion relief valve, a fire protection medium injection interface, protective materials, bolts, etc. The liquid cooling plate 2 is composed of a refrigerant plate, a multi-branch flow channel, a liquid inlet, a liquid outlet, a transfer block, a fixed bracket, etc., and each part is welded by a brazing process. Four battery modules 11 are arranged side by side in the shell of a single energy storage unit 1. A gap is provided between each two adjacent battery modules 11 for the heat pipe cluster 3 to extend into. A total of three heat pipe clusters 3 are provided between the three gaps of the four battery modules 11. A number of battery cells are arranged in each battery module 11, and the bottom of the battery module 11 and the battery cell are covered by the liquid cooling plate 2. Phase change materials have the characteristics of high latent heat and can absorb and release a large amount of heat. The phase change material layer wrapped outside the heat pipe cluster 3 and the thermal conductive gel filled between the battery module 11 and the heat pipe cluster 3, and between the battery module 11 and the liquid cooling plate 2 can absorb the heat generated during the charging and discharging process, so that the overall temperature of the battery module 11 is maintained stable. The present invention provides corresponding heat dissipation components at the bottom of the battery cell and the large side surfaces of the battery cell so that at least two surfaces of the battery cell are fully cooled, thereby achieving the effect of reducing the temperature difference of each battery cell in the battery module 11, thereby improving the cycle life of the battery cell and further improving the overall life of the energy storage system. In addition, it can also reduce the energy consumption of the thermal management system to a certain extent, and further improve the energy conversion efficiency of the energy storage system.

[0025] Please also read Figures 4 to 7 Furthermore, a heat pipe assembly is provided in the energy storage unit 1 of the present invention, and the heat pipe assembly includes a heat pipe cluster 3, a heat dissipation end plate 32 and a heat pipe bracket 33. The heat dissipation end plate 32 is installed above the liquid cooling plate 2, and the heat dissipation end plate 32 is connected to the heat pipe cluster 3. The heat pipe cluster 3 extends from the heat dissipation end plate 32 toward the side of the battery module 11 between the battery modules 11. Specifically, the gravity heat pipe 31 of the heat pipe cluster 3 includes an evaporation section 311, an insulation section 312 and a condensation section 313. The evaporation section 311 is connected to the heat dissipation end plate 32 for heat exchange, the insulation section 312 is arranged between the evaporation section 311 and the condensation section 313 and is connected to the evaporation section 311 and the condensation section 313 as a whole, and the condensation section 313 is arranged between adjacent battery modules 11. Please refer to Figure 7In this embodiment, the cross section of the condensation section 313 is an oblong with a longitudinal dimension greater than a transverse dimension. The condensation section 313 is provided with a number of microporous channels 314 for circulating the cooling medium, that is, the gravity heat pipe 31 in the present invention is a microporous gravity heat pipe. The microporous gravity heat pipe is a heat pipe with a small amount of cooling medium and a capillary core arranged inside. It mainly relies on the vapor-liquid phase change heat transfer of the cooling medium. The thermal resistance is very small, so it has a very high thermal conductivity. The gravity heat pipe 31 in the present invention is made of a metal with a high heat transfer coefficient by flattening. The oblong microporous heat pipe stacked in the height direction has a stronger heat dissipation capacity and heat dissipation efficiency, and can realize multi-heat source and long-distance heat transfer, especially can effectively conduct heat to the large side surface of the battery core. It is easy to understand that the microporous shape and number of holes of the microporous heat pipe can be set according to actual conditions, for example: the microporous shape is set to an ellipse, a waist shape, a triangle, etc. In some other embodiments of the present invention, additional heat dissipation fins can also be installed on the microporous heat pipe. The heat dissipation end plate 32 in the present invention is a fin-type air-cooled end plate, which uses the principle of air-cooled heat dissipation to achieve rapid heat transfer and exchange heat with the evaporation section 311 of the gravity heat pipe 31. In this embodiment, the heat dissipation end plate 32 is vertically arranged above the liquid cooling plate 2 and on one side of the battery module 11, so it has a large heat dissipation area. The heat pipe bracket 33 in the present invention is arranged above the liquid cooling plate 2 and is fixedly connected to the liquid cooling plate 2 as a whole. The heat pipe bracket 33 is fixedly connected to the gravity heat pipe 31 extending between the battery modules 11 as a whole. The heat pipe bracket 33 is relatively fixed to the stacked gravity heat pipes 31 respectively, so as to relatively fix the gravity heat pipes 31 into clusters. In this embodiment, the bottom of the heat pipe bracket 33 is installed on the liquid cooling plate 2, and the cross-section of the upper part of the heat pipe bracket 33 is in the shape of the letter "S", so that the gravity heat pipe 31 is alternately wrapped from the left and right directions. In the present invention, the stacked gravity heat pipes 31 are relatively fixed into a cluster by means of the heat pipe brackets 33 , so that heat can be efficiently transferred in the horizontal direction, that is, in the gaps between the battery modules 11 .

[0026] Please also read Figure 8 and Fig. 9Furthermore, the electrochemical energy storage system of the present invention also includes a first cabinet 5 for accommodating the energy storage unit 1 and a second cabinet 6 for accommodating the electrical components. Specifically, a plurality of energy storage units 1 are stacked in the first cabinet 5, and the first cabinet 5 is provided with a first air outlet 52 and a first air inlet 51, the first air inlet 51 and the first air outlet 52 are located on the first side of the first cabinet 5, and the heat dissipation end plate 32 of the energy storage unit 1 faces the first side; the second cabinet 6 is provided with a second air inlet 61 and a second air outlet 62, the second air inlet 61 and the second air outlet 62 are respectively arranged on the first side and the second side of the second cabinet 6, the first side is located in front of the second cabinet 6, and the second side is located behind the second cabinet 6. In the present embodiment, the first cabinet body 5 and the second cabinet body 6 are fixedly connected as one body, the first cabinet body 5 is arranged above the second cabinet body 6 and the two are separated by upper and lower compartments, the first cabinet body 5 and the second cabinet body 6 are cubic cabinet bodies made of sheet metal, channel steel, square tube and other raw materials by welding, screw connection and the like, and are used to accommodate and protect the energy storage unit 1 and electrical components, the first air inlet 51, the first air outlet 52 and the second air outlet 62 are arranged on the same surface of the cubic cabinet body, close to the end where the heat dissipation end plate 32 is arranged on the energy storage unit 1, the first air inlet 51 is provided with a waterproof shutter 511 and an air inlet fan 512, and the second air inlet 61 is arranged on the other surface opposite to the second air outlet 62, that is, the wind flow direction in the first cabinet body 5 is: in from the top and out from the bottom on the same surface of the cubic cabinet, and the wind flow direction in the second cabinet body 6 is: forward and backward on the two opposite surfaces of the cubic cabinet, the air inlet and outlet effects are good and will not cause thermal short circuit. Furthermore, the first cabinet 5 is provided with an energy management system assembly 53 and a fire protection system assembly 54, and the fire protection system assembly 54 includes at least one of a smoke and temperature detector, a combustible gas detector, and a gas fire extinguishing device, such as a perfluorohexanone fire extinguishing device or an aerosol fire extinguishing device, etc., to deal with the fire risk of the first cabinet 5. The second cabinet 6 is provided with an air-cooled water cooling unit 4 and conventional electrical components such as a high-voltage box 7 and an energy storage converter 8, and also includes a battery slave control module BMU, a communication harness, a power harness, a short-circuit protection device, a connecting copper bus, etc. The air-cooled water cooling unit 4 is connected to the liquid cooling plate 2 through a pipeline passing through the second cabinet 6 and the first cabinet 5. The air-cooled water cooling unit 4 includes components such as a fan, a radiator, and a water pump, which can be used to accelerate the wind flow in the second cabinet 6, improve the air cooling and heat dissipation effect, and transfer the heat to the cooling medium used by the liquid cooling plate 2 by water cooling, and then transport it to the liquid cooling plate 2 by the water pump. It is easy to understand that the air-cooled water cooling unit 4 is provided with a plurality of groups of liquid inlet pipes and liquid outlet pipes, which are respectively connected to the liquid inlet 21 and the liquid outlet 22 on the liquid cooling plate 2 in each energy storage unit 1 .

[0027] Furthermore, the present invention also includes a thermal management system, which is used to control the operation of the liquid cooling plate 2 and the heat pipe cluster 3. Specifically, in the actual operation process of the electrochemical energy storage system of the present invention, the air-cooled water cooling unit 4 and the heat pipe assembly can be operated separately or together according to actual conditions to achieve precise battery cell temperature control effect, reduce the temperature difference of different battery cells, effectively improve the temperature consistency of the battery cells, thereby improving the consistency of the voltage, current, and resistance of each single battery cell during the charging and discharging process, greatly reducing the barrel effect of a single battery cell, and raising the overall electric energy input-output conversion efficiency ratio, thereby increasing the cumulative cycle life of all battery cells, and further improving the economic effect of the energy storage system.

[0028] In summary, the electrochemical energy storage system and thermal management system of the present invention provide corresponding heat dissipation components at the bottom of the battery cell and the large side surfaces of the battery cell, respectively, so that at least two surfaces of the battery cell are fully cooled, so as to achieve the effect of reducing the temperature difference of each battery cell in the battery module, thereby improving the cycle life of the battery cell and further improving the overall life of the energy storage system. In addition, it can also reduce the energy consumption of the thermal management system to a certain extent, and further improve the energy conversion efficiency of the energy storage system.

[0029] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An electrochemical energy storage system, characterized in that: The invention comprises a battery module (11), wherein a liquid cooling plate (2) for cooling the battery module (11) is arranged below the battery module (11), and a heat pipe cluster (3) for cooling the battery module (11) is sandwiched between adjacent battery modules (11), wherein the heat pipe cluster (3) comprises a plurality of stacked gravity heat pipes (31) and a phase change material layer coated on the surface of the gravity heat pipe (31), wherein the phase change material layer is used to absorb heat generated by the battery module (11); and an energy storage unit (1), wherein the energy storage unit (1) comprises a plurality of stacked gravity heat pipes (31) and a phase change material layer coated on the surface of the gravity heat pipe (31), wherein the phase change material layer is used to absorb heat generated by the battery module (11); The battery module (11), between the battery module (11) and the heat pipe cluster (3), and between the battery module (11) and the liquid cooling plate (2) are respectively filled with heat conductive gel; a heat pipe assembly is arranged in the energy storage unit (1), the heat pipe assembly comprises the heat pipe cluster (3) and a heat dissipation end plate (32), the heat dissipation end plate (32) is installed above the liquid cooling plate (2), the heat dissipation end plate (32) is connected to the heat pipe cluster (3), and the heat pipe cluster (3) extends from the heat dissipation end plate (32) toward one side of the battery module (11) into the liquid cooling plate (2). The gravity heat pipe (31) comprises an evaporation section (311), an insulation section (312) and a condensation section (313); the evaporation section (311) is connected to the heat dissipation end plate (32) for heat exchange; the insulation section (312) is arranged between the evaporation section (311) and the condensation section (313) and is respectively connected to the evaporation section (311) and the condensation section (313) as a whole; the condensation section (313) is arranged between adjacent battery modules (11); the cross section of the condensation section (313) is a longitudinal dimension greater than a transverse dimension. The heat pipe assembly is an oblong shape with a size of 2.5 mm, and a plurality of microporous channels (314) for circulating a cooling medium are arranged in the condensing section (313); the heat pipe assembly also includes a heat pipe bracket (33), the heat pipe bracket (33) is arranged above the liquid cooling plate (2) and is integrally connected to the liquid cooling plate (2); the heat pipe bracket (33) is integrally connected to the gravity heat pipe (31) extending between the battery modules (11); the heat pipe bracket (33) is relatively fixed to the stacked gravity heat pipes (31) so as to relatively fix the gravity heat pipes (31) into a cluster.

2. The electrochemical energy storage system according to claim 1, characterized in that: It also includes an air-cooled water cooling unit (4), the air-cooled water cooling unit (4) being in communication with the liquid cooling plate (2), and the air-cooled water cooling unit (4) being used to dissipate heat for a cooling medium flowing through the liquid cooling plate (2).

3. The electrochemical energy storage system according to claim 1, characterized in that: The invention comprises a first cabinet (5) for accommodating the energy storage unit (1), wherein a plurality of the energy storage units (1) are stacked in the first cabinet (5), and the first cabinet (5) is provided with a first air inlet (51) and a first air outlet (52), wherein the first air inlet (51) and the first air outlet (52) are arranged on a side close to the heat dissipation end plate (32), and the first air inlet (51) is arranged above the first air outlet (52).

4. The electrochemical energy storage system according to claim 2, characterized in that: The invention comprises a second cabinet (6) for accommodating electrical components, the air-cooled water cooling unit (4) being arranged in the second cabinet (6), the second cabinet (6) being provided with a second air inlet (61) and a second air outlet (62), the second air inlet (61) and the second air outlet (62) being arranged on a first side and a second side of the second cabinet (6), respectively, the first side being located in front of the second cabinet (6), and the second side being located at the rear of the second cabinet (6).

5. The electrochemical energy storage system according to claim 2 or 3, characterized in that: The air-cooled water cooling unit (4) is connected to the liquid cooling plate (2) via a pipeline passing through the second cabinet (6) and the first cabinet (5).

6. A thermal management system, characterized in that: It is used to control the electrochemical energy storage system according to any one of claims 1 to 5, and the thermal management system is used to control the operation of the liquid cooling plate (2) and the heat pipe cluster (3).

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