Liquid cooling pipeline, energy storage system and pressure control method thereof

Abstract

The present application discloses a liquid cooling pipeline, an energy storage system and a pressure control method thereof. The liquid cooling pipeline includes an outer tube, an inner tube and a support layer. The inner tube is arranged inside the outer tube. In the radial direction of the outer tube, the inner tube and the outer tube are spaced apart. The inner tube is used to fill the coolant. The inner tube is configured to expand or contract when the pressure of the coolant changes. The support layer is arranged between the outer tube and the inner tube and surrounds the inner tube. At least part of the support layer abuts against the inner wall surface of the outer tube and the outer wall surface of the inner tube. The support layer is configured to be deformable when the inner tube expands or contracts. The liquid cooling pipeline, energy storage system and pressure control method thereof of the present application can solve the problem of excessive space occupation or reduced coolant flow, and increase the tolerance capacity of the liquid cooling pipeline.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a liquid cooling pipeline, an energy storage system and a pressure control method thereof. Background Art

[0002] The energy storage system mainly uses liquid cooling units to cool down power devices (such as battery packs). Taking the battery pack as an example, the coolant is transported to the battery pack through the liquid cooling pipeline, and heat is exchanged with the battery pack through the liquid cooling pipeline to achieve the purpose of heat dissipation, which has a high cooling efficiency.

[0003] In the related art, in order to realize the function of regulating the pressure of the energy storage system, an expansion tank is usually set in the liquid cooling unit. However, this method will excessively occupy the space inside the liquid cooling unit. Alternatively, the volume of the internal pipeline of the liquid cooling plate is reduced. However, this method will cause the flow of coolant passing through the liquid cooling plate to decrease, affecting the cooling effect. Summary of the invention

[0004] The embodiments of the present application disclose a liquid cooling pipeline, an energy storage system and a pressure control method thereof, which can solve the above-mentioned problems of excessive space occupation or reduced coolant flow and increase the tolerance capacity of the liquid cooling pipeline.

[0005] In order to achieve the above objectives, in a first aspect, an embodiment of the present application discloses a liquid cooling pipeline, comprising:

[0006] External pipe;

[0007] an inner tube, the inner tube being arranged inside the outer tube, the inner tube being spaced apart from the outer tube in a radial direction of the outer tube, the inner tube being used to be filled with a coolant, and the inner tube being configured to expand or contract when the pressure of the coolant changes; and

[0008] A support layer is provided between the outer tube and the inner tube and surrounds the inner tube. At least a portion of the support layer abuts against an inner wall surface of the outer tube and an outer wall surface of the inner tube. The support layer is configured to be deformable when the inner tube expands or contracts.

[0009] As an optional implementation, in an embodiment of the first aspect of the present application, the support layer is formed with a cavity, the extension length of the cavity is consistent with the extension length of the inner tube, and the cavity is configured to provide a space for the support layer to deform.

[0010] By providing a support layer with a cavity, the support layer can be more easily deformed when squeezed by the inner tube, and sufficient expansion space is provided for the inner tube, so that the liquid cooling pipeline can adjust its shape according to the change of internal coolant pressure to absorb the expansion of the inner tube or compensate for the contraction of the inner tube.

[0011] As an optional implementation, in an embodiment of the first aspect of the present application, the cavity of the support layer has a first opening, and the inner wall surface and / or the outer wall surface closes the first opening.

[0012] Such a configuration can provide a larger deformation space. When the inner tube expands due to the increase in coolant pressure, the support layer can be sufficiently deformed after being squeezed by the inner tube to absorb the expansion of the inner tube, so that the liquid cooling pipeline can accommodate a larger pressure change. In addition, since the temperature of the coolant will increase when the liquid cooling pipeline is used as a liquid outlet, in addition to the need for pressure regulation, there is also a certain heat dissipation requirement. By adopting a semi-enclosed support layer, there is a larger air layer between the outer tube and the inner tube, which is more conducive to dissipating heat into the cavity, thereby cooling the coolant.

[0013] As an optional implementation, in an embodiment of the first aspect of the present application, the supporting layer has a first curved surface and a second curved surface arranged opposite to each other, the first curved surface is configured as a side close to the inner wall surface, and the second curved surface is configured as a side away from the inner wall surface, and the first curved surface and the second curved surface both protrude toward the outer wall surface so that the supporting layer constructs the first opening facing the inner wall surface, the cavity is formed between the first curved surface and the inner wall surface, and the second curved surface abuts against the outer wall surface.

[0014] By setting the support layer as an arc-shaped structure with an arc-shaped surface and making the first opening face the inner wall surface of the outer tube, the support layer can be more easily deformed when squeezed by the inner tube, and the support layer can also be easily rebounded when the inner tube retracts. In this process, the support layer with an arc-shaped structure is not easily damaged, which is more conducive to the reliability of the support layer.

[0015] As an optional implementation, in an embodiment of the first aspect of the present application, the support layer includes a plurality of support frames, and the plurality of support frames are interconnected along the circumferential direction of the inner tube, and each of the support frames extends along the length direction of the inner tube, and at least part of the support frames have the first arcuate surface and the second arcuate surface arranged opposite to each other, so that at least part of the support frames construct the first opening facing the inner wall surface.

[0016] Compared with an integrated support layer, by configuring the support to include multiple support frames, while ensuring the supporting function and deformability of the support layer, the deformation between the support frames is not affected by the overall structure. Even if one of the support frames fails, it will not have a significant impact on other support frames. During maintenance and replacement, only one needs to be replaced without replacing the entire support layer, which is more conducive to maintenance and saves costs.

[0017] As an optional implementation, in an embodiment of the first aspect of the present application, a plurality of protrusions are provided on the inner wall surface, and the plurality of protrusions are arranged at intervals along the circumference of the inner tube, and both sides of each support frame abut between two adjacent protrusions, and the protrusions are configured to limit the position of the support frame in the circumferential direction of the inner tube.

[0018] By arranging multiple protrusions on the inner wall surface, arranging the support frame between two adjacent protrusions, and using the protrusions to limit the support frame, it is not only possible to avoid shaking and shifting of the support frame between the outer tube and the inner tube, thereby ensuring the connection stability of the support layer, but also possible to limit the degree of deformation of the support layer caused by being squeezed by the inner tube, thereby effectively limiting the expansion of the inner tube, and further ensuring that the cooling pressure of the liquid cooling pipeline of the energy storage system is within a reasonable operating range.

[0019] As an optional implementation, in an embodiment of the first aspect of the present application, the support layer includes a plurality of support tubes, the plurality of support tubes are interconnected along the circumferential direction of the inner tube, each of the support tubes extends along the length direction of the inner tube, and at least some of the support tubes are closed in their own circumferential direction to form the cavity.

[0020] By setting the support layer as a plurality of support tubes containing air, the support layer has good support properties, which can reduce the expansion of the inner tube. In addition, due to the large thermal resistance of air, it can also effectively delay the leakage of the coolant at a lower temperature in the inner tube to the outer tube, thereby helping to improve the thermal insulation capacity of the liquid cooling pipeline.

[0021] As an optional implementation, in an embodiment of the first aspect of the present application, the cross-sectional shape of the support tube is circular, and / or both ends of the support tube are configured as closed ends.

[0022] By setting the cross-sectional shape of the support tube to be circular and combining it with an air layer having a higher thermal resistance inside, the support layer has a better support effect.

[0023] Such an arrangement enables the sealed support tube to undergo good elastic deformation when subjected to the expansion of the inner tube, and to return to its original shape without permanent deformation when the inner tube retracts, and is more conducive to maintaining good performance within a temperature range of -40°C to 120°C.

[0024] As an optional implementation, in an embodiment of the first aspect of the present application, the liquid cooling pipeline is a liquid outlet pipe, and the liquid outlet pipe is configured to be connected between the liquid outlet of the liquid cooling plate and the liquid cooling unit, and in the liquid outlet pipe, the cavity of the support layer has a first opening.

[0025] As an optional implementation, in an embodiment of the first aspect of the present application, the liquid cooling pipeline is a liquid inlet pipe, and the liquid inlet pipe is configured to be connected between the liquid inlet of the liquid cooling plate and the liquid cooling unit, and in the liquid inlet pipe, the cavity of the support layer is configured as a closed cavity.

[0026] As an optional implementation manner, in an embodiment of the first aspect of the present application, when the liquid cooling pipeline serves as a liquid outlet pipe, the support layer is made of metal;

[0027] When the liquid cooling pipeline is used as a liquid inlet pipe, the supporting layer is made of plastic material.

[0028] As the temperature of the coolant inside the liquid outlet pipe increases, the coolant expands, causing the pressure to increase, causing the inner tube to expand and contact the metal support frame. Since the inner tube is in direct contact with the coolant, the wall temperature of the inner tube is higher than the support frame. The metal support frame has better heat conduction and heat absorption effects, which is more conducive to the cooling effect of the coolant returning to the liquid cooling unit.

[0029] By using a plastic support tube, the elastic deformation performance and the ability to rebound to restore the original shape of the support tube are guaranteed under the premise of good support. In addition, the plastic support tube has a low thermal conductivity and good thermal insulation performance, which can effectively prevent heat transfer and improve the thermal insulation performance of the liquid cooling pipeline when it is used as a liquid inlet pipe, thereby optimizing the heat dissipation effect of the coolant on the battery pack.

[0030] As an optional implementation, in an embodiment of the first aspect of the present application, the thickness of the outer tube is 1 mm to 1.25 mm, and / or the thickness of the inner tube is 1 mm to 1.25 mm.

[0031] By limiting the thickness of the outer tube within a reasonable range, the outer tube can block the inner tube and the support layer to a certain extent to prevent the inner tube from over-expanding and permanently deforming, while avoiding the outer tube from being too thick, which will cause the volume of the liquid cooling pipeline to be too large. By limiting the thickness of the inner tube within a reasonable range, the inner tube can have appropriate elastic deformation space while ensuring the reliability of the inner tube.

[0032] In a second aspect, the present application further discloses an energy storage system, comprising a liquid cooling unit, a battery pack, and the liquid cooling pipeline as described in the first aspect above, wherein the battery pack and the liquid cooling unit are connected via the liquid cooling pipeline.

[0033] As an optional implementation, in an embodiment of the second aspect of the present application, the liquid cooling unit includes an expansion tank, which is connected to the liquid outlet of the battery pack through the liquid cooling pipeline and is used to adjust the pressure of the coolant in the liquid cooling pipeline.

[0034] On the basis that the liquid cooling pipeline deforms due to the change of internal coolant pressure to achieve pressure regulation of the liquid cooling pipeline, the expansion tank is combined to provide additional pressure to the energy storage system or reduce the pressure, so as to further improve the tolerance capacity of the energy storage system and ensure the safe operation of the energy storage system.

[0035] As an optional implementation, in an embodiment of the second aspect of the present application, the expansion tank includes a liquid storage chamber and a gas storage chamber, the liquid storage chamber is used to be filled with coolant, the gas storage chamber is used to be filled with gas, and the gas storage chamber is connected to the support layer of the liquid cooling pipeline;

[0036] The liquid cooling unit also includes an air pump and a shut-off valve, wherein the shut-off valve is connected between the air pump and the air storage chamber, and the air storage chamber is configured to be pressurized or depressurized under the action of the shut-off valve and the air pump to adjust the pressure of the coolant in the liquid cooling pipeline.

[0037] By adding an air pump and a shut-off valve to the refrigeration unit and connecting the air storage chamber of the expansion tank to the supporting layer of the liquid cooling pipeline, when the pressure in the liquid cooling pipeline is too high, the shut-off valve can be opened to reduce the pressure in the air storage chamber of the expansion tank. Due to the pressure difference, the coolant in the liquid cooling pipeline will enter the liquid storage chamber of the expansion tank to accommodate more coolant. At the same time, since the supporting layer of the liquid cooling pipeline is connected to the air storage chamber, the pressure of the interlayer between the outer tube and the inner tube is reduced, the pressure of the coolant inside the inner tube is greater than the air pressure of the interlayer, the inner tube expands, and the internal volume of the liquid cooling pipeline increases, so that the pressure of the liquid cooling pipeline is reduced.

[0038] When the pressure in the liquid cooling pipeline is too low, the shut-off valve and the air pump can be opened at the same time, and the air pump can be used to inflate the air storage chamber of the expansion tank, so that the pressure in the air storage chamber increases. At this time, since the pressure in the liquid storage chamber is lower than that in the air storage chamber, the coolant in the liquid storage chamber is squeezed into the pipeline of the energy storage system. At the same time, since the pressure of the interlayer between the outer tube and the inner tube connected to the supporting layer of the liquid cooling pipeline and the air storage chamber increases, the pressure of the coolant inside the inner tube is lower than the air pressure in the interlayer, the inner tube contracts, and the internal volume of the liquid cooling pipeline becomes smaller, causing the pressure in the liquid cooling pipeline to increase.

[0039] In the third aspect, the present application also discloses an energy storage system, comprising a liquid cooling unit, a battery pack and the liquid cooling pipeline as described in the first aspect above, wherein the battery pack and the liquid cooling unit are connected through the liquid cooling pipeline, and the liquid cooling unit comprises an expansion tank, a detection device and a control device, wherein the expansion tank is arranged on the liquid outlet pipeline of the battery pack, and the air storage chamber of the expansion tank is connected to the supporting layer of the liquid cooling pipeline, the detection device is used to detect the return liquid pressure of the liquid cooling unit, and the control device is used to control the expansion tank to adjust the pressure of the coolant in the liquid cooling pipeline according to the return liquid pressure of the liquid cooling unit.

[0040] With such an arrangement, the return liquid pressure of the liquid cooling unit can be detected by the detection device. When the pressure in the liquid cooling pipeline is too high or too low, the expansion tank is controlled by the control device to adjust the pressure of the coolant in the liquid cooling pipeline, thereby realizing active regulation of the pressure of the energy storage system.

[0041] In a fourth aspect, the present application further discloses a pressure control method for an energy storage system, wherein the energy storage system is the energy storage system as described in the third aspect above, and the method comprises:

[0042] Controlling the detection device to detect the liquid return pressure of the liquid cooling unit;

[0043] According to the return liquid pressure of the liquid cooling unit, the expansion tank is controlled to adjust the pressure of the coolant in the liquid cooling pipeline.

[0044] Compared with the prior art, the beneficial effects of this application are:

[0045] The present application provides a liquid cooling pipeline, an energy storage system and a pressure control method thereof. The liquid cooling pipeline is divided into a three-layer structure, and an inner tube in contact with the coolant expands or contracts when the coolant pressure changes, and a deformable support layer is provided between the outer tube and the inner tube. When the ambient temperature rises or the operating load increases, the coolant temperature rises, causing the coolant to expand and the pressure to rise. The inner tube can expand, and the internal volume of the pipeline will increase. At the same time, the contact area between the inner tube and the middle support layer increases, and the support layer can dissipate heat to the interlayer air, which can play a role in cooling the return water coolant of the unit; when the coolant is insufficient, the pressure of the coolant inside the pipeline will drop, causing the inner tube to rebound, and the internal volume of the pipeline will become smaller, so that the static pressure of the coolant can be maintained unchanged or the drop can be reduced, thereby improving the tolerance capacity of the liquid cooling pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the structure when the liquid cooling pipeline provided for this application is a liquid outlet pipe;

[0048] Figure 2 A schematic diagram of the exploded structure when the liquid cooling pipeline provided in this application is a liquid outlet pipe;

[0049] Figure 3 A schematic top view of the liquid cooling pipeline provided in this application when it is a liquid outlet pipe;

[0050] Figure 4A schematic diagram of the structure when the liquid cooling pipeline provided for this application is a liquid inlet pipe;

[0051] Figure 5 A schematic diagram of the exploded structure when the liquid cooling pipeline provided in this application is a liquid inlet pipe;

[0052] Figure 6 A schematic top view of the liquid cooling pipeline provided in this application when it is a liquid inlet pipe;

[0053] Figure 7 A schematic diagram of the energy storage system structure provided for this application;

[0054] Figure 8 A flow chart of a pressure control method for an energy storage system provided in this application.

[0055] Description of reference numerals:

[0056] 100, liquid cooling pipeline; 10, outer tube; 10a, inner wall surface; 10b, protrusion; 20, inner tube; 20a, outer wall surface; 30, support layer; 301, cavity; 301a, first opening; 302, air gap; 30a, first arc surface; 30b, second arc surface; 31, support frame; 32, support tube;

[0057] 200, energy storage system; 201, liquid cooling unit; 2011, expansion tank; 2011a, liquid storage chamber, 2011b, gas storage chamber; 2012, plate heat exchanger; 2013, air pump, 2014, shut-off valve; 202, battery pack. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] In the present application, the terms "upper", "lower", "inner", "outer", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0060] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0061] In addition, the terms "disposed", "provided with", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0063] The energy storage system mainly uses liquid cooling units to cool down power devices (such as battery packs). Taking the battery pack as an example, the coolant is transported to the battery pack through the liquid cooling pipeline, and heat is exchanged with the battery pack through the liquid cooling pipeline to achieve the purpose of heat dissipation, which has a high cooling efficiency.

[0064] In the liquid cooling unit of the energy storage system, the pressure of the coolant in the liquid cooling unit of the energy storage system may change due to factors such as temperature changes, small leakage or evaporation of the coolant, too little or too much coolant filling, etc., which may affect the normal operation of the liquid cooling unit of the energy storage system and even cause the liquid cooling pipeline to break or fall off. It can be seen that in order to ensure the normal operation of the liquid cooling system and the safe energy storage of the battery, and to avoid system failure or damage caused by excessive or low pressure, pressure regulation is important for the safety and reliability of the energy storage system.

[0065] The liquid cooling pipelines used in the energy storage system in the related art are mainly nylon tubes, and the pipelines cannot realize the function of automatic liquid replenishment and pressure adjustment. In order to improve the tolerance capacity (the range of pressure to be accommodated) of the energy storage system, an expansion tank is usually added to the liquid cooling unit on the market. The expansion tank can be connected to any node of the energy storage system, and the expansion tank is used to provide additional pressure to the energy storage system or reduce the pressure, thereby ensuring that the pressure of the liquid cooling unit of the energy storage system is maintained in an appropriate range. However, the volume of the configured expansion tank is usually large. For example, a 5kW liquid cooling unit needs to be equipped with a 2L expansion tank, which will occupy excessive space inside the liquid cooling unit.

[0066] In addition, there is also a method of reducing the volume of the internal pipeline of the liquid cooling plate to reduce the expansion or contraction of the coolant due to temperature changes. However, this method will cause the flow velocity of the liquid cooling pipeline to increase, and the flow resistance will also increase, which may cause the flow of coolant passing through the liquid cooling plate to decrease, affecting the heat exchange effect of the battery pack and causing the battery temperature to rise too high.

[0067] Based on the above, the present application improves the structure of the liquid cooling pipeline, divides the liquid cooling pipeline into a three-layer structure, sets the inner tube for contacting the coolant to expand or contract when the coolant pressure changes, and sets a deformable support layer between the outer tube and the inner tube. When the ambient temperature rises or the operating load increases, the coolant temperature rises, causing the coolant to expand, the pressure rises, the inner tube can expand, and the internal volume of the pipeline will increase. At the same time, the contact area between the inner tube and the middle support layer increases, and the support layer can dissipate heat to the interlayer air, which can play a role in cooling the return water coolant of the cooling unit. When the coolant is insufficient, the pressure of the coolant inside the pipeline will drop, causing the inner tube to rebound, and the internal volume of the pipeline will become smaller, so that the static pressure of the coolant can be maintained unchanged or the drop can be reduced, thereby improving the tolerance capacity of the liquid cooling pipeline. Therefore, the shape of the liquid cooling pipeline can be adjusted by relying on the change of the coolant pressure inside the liquid cooling pipeline to realize the pressure regulation of the energy storage system, without occupying the internal space of the liquid cooling unit, and without reducing the flow in the liquid cooling plate.

[0068] The technical solution of the present application will be further described below in conjunction with embodiments and drawings.

[0069] In the first aspect, the embodiment of the present application discloses a liquid cooling pipeline 100, which can be applied to the energy storage system 200, and the liquid cooling pipeline 100 can be connected between the liquid cooling unit 201 and the battery pack 202 for circulating the cooling liquid. Specifically, the cooling liquid from the liquid cooling unit 201 is led out by the liquid cooling pipeline 100, and connected to the liquid cooling plate of the battery pack 202 to perform heat exchange on the battery, and then the cooling liquid after heat exchange is returned to the liquid cooling unit 201 through the liquid cooling pipeline 100 to complete the liquid cooling cycle.

[0070] It is worth noting that in the energy storage system 200, the liquid cooling pipeline 100 provided in the embodiment of the present application can be used as an inlet pipe or an outlet pipe, wherein the inlet pipe is connected between the water outlet of the liquid cooling unit 201 and the battery pack 202. The outlet pipe is connected between the battery pack 202 and the return water end of the liquid cooling unit 201. The coolant flowing out of the liquid cooling unit 201 passes through the inlet pipe to perform heat exchange on the battery pack 202. The coolant after heat exchange flows back to the liquid cooling unit 201 through the outlet pipe to complete the cycle.

[0071] See also Figure 1 and Figure 2 , Figure 1This is a schematic diagram of the structure of the liquid cooling pipeline 100 as a liquid outlet pipe in the embodiment of the present application. Figure 2 The liquid cooling pipeline 100 is a schematic diagram of the structure of the liquid inlet pipe in the embodiment of the present application. In some possible implementations, the liquid cooling pipeline 100 may include an outer tube 10, an inner tube 20 and a support layer 30. The inner tube 20 is arranged inside the outer tube 10. In the radial direction of the outer tube 10, the inner tube 20 and the outer tube 10 are spaced apart. The inner tube 20 is used to fill the coolant. The inner tube 20 is configured to expand or contract when the pressure of the coolant changes. The support layer 30 is arranged between the outer tube 10 and the inner tube 20, and is arranged around the inner tube 20. At least part of the support layer 30 abuts against the inner wall surface 10a of the outer tube 10 and the outer wall surface 20a of the inner tube 20. The support layer 30 is configured to be deformable when the inner tube 20 expands or contracts.

[0072] By dividing the liquid cooling pipeline 100 into a three-layer structure, the inner tube 20 in contact with the coolant expands or contracts when the coolant pressure changes, and a deformable support layer 30 is provided between the outer tube 10 and the inner tube 20. In this way, when the ambient temperature rises or the operating load increases, the coolant temperature rises, causing the coolant to expand and the pressure to rise, the inner tube 20 can expand, and the internal volume of the liquid cooling pipeline 100 will increase. At the same time, the contact area between the inner tube 20 and the middle support layer 30 increases, and the support layer 30 can dissipate heat to the interlayer air, which can play a role in cooling the return water coolant of the unit. When the coolant is insufficient, the pressure of the coolant inside the liquid cooling pipeline 100 will drop, causing the inner tube 20 to rebound and the internal volume of the pipeline to become smaller, thereby maintaining the static pressure of the coolant unchanged or reducing the drop. Therefore, the shape of the liquid cooling pipeline 100 can be adjusted by relying on the change in the coolant pressure inside the liquid cooling pipeline 100, realizing the pressure regulation of the energy storage system 200, and then improving the tolerance capacity of the liquid cooling pipeline 100.

[0073] It should be noted that, in the embodiment of the present application, the shape of the liquid cooling pipeline 100 can be adjusted by the change of the coolant pressure inside the liquid cooling pipeline 100 to achieve pressure regulation of the energy storage system 200. In one example, an expansion tank 2011 can be further configured, but since the liquid cooling pipeline 100 itself can achieve pressure regulation, the configured expansion tank 2011 can be of small capacity. At this time, under the premise of being able to effectively achieve pressure regulation, the space occupied by the liquid cooling unit 201 will be reduced. In another example, the setting of the expansion tank 2011 can be completely cancelled to minimize the occupation of the internal space of the liquid cooling unit 201.

[0074] In addition, compared to the method of reducing the volume of the internal pipeline of the liquid cooling plate, the embodiment of the present application can achieve pressure regulation by utilizing the structure of the liquid cooling tube itself, without the need to improve the liquid cooling plate, thereby avoiding the reduction of the coolant flow rate and affecting the heat exchange effect of the battery pack 202, thereby avoiding the temperature rise of the battery pack 202.

[0075] It is worth noting that the deformations of the inner tube 20 and the support layer 30 are elastic deformations. The inner tube 20 is in direct contact with the coolant, and its material needs to meet the requirement of not chemically reacting with the coolant, and has a certain water resistance, so that it is not easily damaged during long-term immersion in the coolant. The support layer 30 can undergo elastic deformation and has a certain supporting effect. The outer tube 10, as a protective layer of the liquid cooling pipeline 100, in addition to the protective function, can also prevent the inner tube 20 from excessive expansion and causing permanent deformation.

[0076] Optionally, the material of the inner tube 20 can be a material that can be deformed by liquid pressure, such as TPU (Thermoplastic polyurethane) material, PU (Polyurethane) material, etc. The inner tube 20 made of TPU or PU material has an elastic deformation temperature range of -40°C to 120°C, which can meet the requirements of energy storage scenarios and is inexpensive.

[0077] The material of the outer tube 10 can be nylon materials such as PA12 (Polyamide12) and PA (Polyamide). By setting the nylon outer tube 10 outside the entire liquid cooling pipeline 100, its rebound stress can effectively prevent the inner tube 20 from excessive expansion.

[0078] In order to enable the inner tube 20 to be effectively deformed, in some possible implementations, see Figure 1 The support layer 30 is formed with a cavity 301, and the extension length of the cavity 301 is consistent with the extension length of the inner tube 20. The cavity 301 is configured to provide a space for the support layer 30 to deform. By providing the support layer 30 formed with the cavity 301, the support layer 30 can be more easily deformed when squeezed by the inner tube 20, and sufficient expansion space is provided for the inner tube 20, so that the liquid cooling pipeline 100 can adjust its shape by changing the internal coolant pressure to absorb the expansion of the inner tube 20 or compensate for the contraction of the inner tube 20.

[0079] It should be noted that, in addition to the cavity 301 formed by the support layer 30 described above, an air gap 302 is also formed between the support layer 30 and the outer tube 10 and the inner tube 20 to provide elastic deformation space for the inner tube 20.

[0080] In some possible implementations, the thickness of the outer tube 10 is 1 mm to 1.25 mm. Optionally, the thickness of the outer tube 10 may be 1 mm or 1.25 mm. By limiting the thickness of the outer tube 10 to a reasonable range, the outer tube 10 can block the inner tube 20 and the support layer 30 to a certain extent to prevent the inner tube 20 from excessively expanding and permanently deforming, while preventing the outer tube 10 from being too thick, which causes the volume of the liquid cooling pipeline 100 to be too large.

[0081] In some possible implementations, the thickness of the inner tube 20 is 1 mm to 1.25 mm. Optionally, the thickness of the inner tube 20 may be 1 mm or 1.25 mm. By limiting the thickness of the inner tube 20 to a reasonable range, the inner tube 20 can have an appropriate elastic deformation space while ensuring the reliability of the inner tube 20.

[0082] If the thickness of the inner tube 20 is too large, the inner tube 20 is not easy to expand when the coolant pressure increases, and the elastic deformation space is small, which cannot meet the tolerance requirements of the liquid cooling pipeline 100. If the thickness of the inner tube 20 is too small, the inner tube 20 is easy to expand excessively when the coolant pressure increases, and even cause the inner tube 20 to be damaged.

[0083] It should be noted that the thickness of the outer tube 10 and the inner tube 20 can be selected according to the pressure in the energy storage system 200. When the pressure is high, the thickness of the pipeline can be appropriately increased to enable the liquid cooling pipeline 100 to operate normally, and to avoid damage to the pipeline due to excessive pressure and thin thickness of the pipeline. When the pressure is low, the thickness of the pipeline can be appropriately reduced to save materials and reduce costs while ensuring the normal operation of the liquid cooling pipeline.

[0084] When the liquid cooling unit 201 is running, when the pressure of the coolant inside the liquid cooling pipeline 100 increases, the inner tube 20 is stretched open, and the internal volume of the inner tube 20 increases, that is, the volume of the coolant contained increases. When the coolant is insufficient, the coolant pressure inside the inner tube 20 will drop, causing the inner tube 20 to rebound and the internal volume of the inner tube 20 to decrease. Therefore, the shape of the liquid cooling pipeline 100 is adjusted by relying on the change in the liquid pressure inside the pipeline to maintain the static pressure of the coolant unchanged or reduce the drop.

[0085] It is understandable that during the operation of the liquid cooling unit 201 of the energy storage system 200, the outlet pressure is usually higher than the return pressure because the coolant needs to overcome the friction resistance of the pipeline, the head of the water pump and other factors. Exemplarily, the dynamic outlet pressure of the liquid cooling unit 201 during operation is usually 2.0 bar to 2.4 bar, and the return pressure is usually 1.2 bar to 1.5 bar. It can be seen that the pressure of the coolant before and after the battery pack 202 will be different. Then, due to the different coolant pressures, the liquid cooling pipeline 100 connected to the front and back of the battery pack 202 will be deformed to varying degrees. Therefore, the liquid cooling pipeline 100 in the embodiment of the present application needs to be optimized for different pressures. The following will be described in detail using the liquid cooling pipeline 100 as an example of a liquid outlet pipe and a liquid inlet pipe.

[0086] The liquid cooling circuit 100 provided in the embodiment of the present application may be a liquid outlet pipe, which is configured to be connected between the liquid outlet of the liquid cooling plate and the liquid cooling unit 201. In the liquid outlet pipe, the cavity 301 of the support layer 30 has a first opening 301a. It can be understood that the liquid cooling plate is arranged in the battery pack 202, and a flow channel for the flow of the coolant is provided inside the liquid cooling plate. After heat exchange with the battery, the coolant flows out from the liquid outlet and flows back to the liquid cooling unit 201 through the liquid outlet pipe.

[0087] It should be noted that the length extension direction of the outer tube 10, the inner tube 20 and the support layer 30 are consistent, and the extended lengths are the same, that is, the support layer 30 extends from one end of the outer tube 10 and the inner tube 20 to the other end, ensuring that the support layer 30 plays a regulating role in the flow of the coolant in the entire liquid cooling pipeline 10.

[0088] See also Figure 3 to Figure 4 In some possible implementations, the cavity 301 of the support layer 30 has a first opening 301a, and the inner wall surface 10a and / or the outer wall surface 20a close the first opening 301a. That is, the support layer 30 is semi-enclosed on its own periphery. Such a configuration can provide a larger deformation space. When the inner tube 20 expands due to the increase in the coolant pressure, the support layer 30 can be deformed to a certain extent after being squeezed by the inner tube 20 to absorb the expansion of the inner tube 20, so that the liquid cooling pipeline 100 can accommodate a larger pressure change. In addition, since the temperature of the coolant will increase when the liquid cooling pipeline 100 is used as a liquid outlet pipe, in addition to the need for pressure regulation, there is also a certain heat dissipation requirement. By adopting a semi-enclosed support layer 30, there is a larger air layer between the outer tube 10 and the inner tube 20, which is more conducive to dissipating heat to the cavity 301, thereby achieving the effect of cooling the coolant.

[0089] In the liquid cooling circuit 100, the first opening 301a can be closed by the inner wall surface 10a of the outer tube 10, that is, the first opening 301a is arranged toward the outer tube 10. Alternatively, the first opening 301a can be closed by the outer wall surface 20a of the inner tube 20, that is, the first opening 301a is arranged toward the inner tube 20.

[0090] Continue reading Figure 4 In some possible implementations, the support layer 30 has a first curved surface 30a and a second curved surface 30b that are arranged opposite to each other, the first curved surface 30a is configured as a side close to the inner wall surface 10a, and the second curved surface 30b is configured as a side away from the inner wall surface 10a, and the first curved surface 30a and the second curved surface 30b both protrude toward the outer wall surface 20a, so that the support layer 30 is constructed with a first opening 301a facing the inner wall surface 10a, a cavity 301 is formed between the first curved surface 30a and the inner wall surface 10a, and the second curved surface 30b abuts against the outer wall surface 20a. By setting the support layer 30 to be an arc-shaped structure with an arc-shaped surface and making the first opening 301a face the inner wall surface 10a of the outer tube 10, the support layer 30 can be more easily deformed when squeezed by the inner tube 20, and the support layer 30 can also be easily rebounded when the inner tube 20 retracts. In this process, the support layer 30 with an arc-shaped structure is not easily damaged, which is more conducive to the reliability of the support layer 30.

[0091] In addition, by setting the first opening 301a toward the outer tube 10, since the second curved surface 30b abuts against the inner wall surface 20a of the inner tube 20, when the inner tube 20 is squeezed and deformed, the contact area between the inner tube 20 and the support layer 30 can be made larger, which is more conducive to conducting the temperature of the coolant in the inner tube 20 to the support layer 30 and dissipating heat to the cavity 301, thereby being more conducive to the cooling effect of the coolant.

[0092] In some possible implementations, the support layer 30 may be integrally provided. For example, in the radial direction of the liquid cooling pipeline 100 , the cross-sectional shape of the support layer 30 is wavy-shaped, and the wavy support layer 30 is provided around the outer circumference of the inner tube 20 .

[0093] Of course, in some possible implementations, the support layer 30 can be set separately. The support layer 30 can include a plurality of support frames 31, and the plurality of support frames 31 are connected to each other along the circumference of the inner tube 20, and each support frame 31 extends along the length direction of the inner tube 20, and at least part of the support frames 31 have a first arc surface 30a and a second arc surface 30b set opposite to each other, so that at least part of the support frames 31 are constructed with a first opening 301a facing the inner wall surface 10a. Compared with the support layer 30 set as a whole, by setting the support to include a plurality of support frames 31, under the premise of ensuring the support function and deformability of the support layer 30, the deformation between the support frames 31 is not affected by the whole, even if one of the support frames 31 fails, it will not have a significant impact on the other support frames 31, and only one needs to be replaced during maintenance and replacement, without replacing the entire support layer 30, which is more conducive to maintenance and saves costs.

[0094] In one example, each support frame 31 has a first arcuate surface 30a and a second arcuate surface 30b disposed opposite to each other, so that each support frame 31 is configured with a first opening 301a facing the inner wall surface 10a. On the basis of arranging a plurality of support frames 31 around the outer circumference of the inner tube 20 to form the support layer 30, each support frame 31 is configured as an arcuate structure with an opening, so that the support layer 30 is more likely to deform when squeezed by the inner tube 20, and the support layer 30 is also more likely to rebound when the inner tube 20 retracts.

[0095] In another example, a portion of the support frame 31 has a first arcuate surface 30a and a second arcuate surface 30b disposed opposite to each other, so that the portion of the support frame 31 is configured with a first opening 301a facing the inner wall surface 10a. The other portion of the support frame 31 is a closed structure having a cavity 301, and the two portions of the support frame 31 can be cross-arranged along the circumferential direction of the inner tube 20. In this way, while being able to meet the deformation caused by the extrusion of the inner tube 20, the excessive deformation of the inner tube 20 can also be avoided.

[0096] In other words, the support frame 31 is a curved support plate, which is arranged in an arc shape between the outer tube 10 and the inner tube 20, and the bending direction is set toward the inner tube 20. The first arc surface 30a is the concave side of the arc-shaped support frame 31, facing the inner wall surface 10a of the outer tube 10, and the second arc surface 30b is the convex side 10b of the arc-shaped support frame 31, which contacts the outer wall surface 20a of the inner tube 20.

[0097] It can be understood that the support frame 31 has two opposite side surfaces for forming the first opening 301 a , and the two opposite sides are both in contact with the inner wall surface 10 a , so that the inner wall surface 10 a closes the first opening 301 a .

[0098] In order to prevent the deformation of the support layer 30 from being too large, resulting in excessive expansion of the inner tube 20, refer to Figure 4 In some possible implementations, a plurality of protrusions 10b are provided on the inner wall surface 10a, and the plurality of protrusions 10b are arranged at intervals along the circumference of the inner tube 20. Both sides of each support frame 31 abut between two adjacent protrusions 10b, and the protrusions 10b are configured to limit the position of the support frame 31 in the circumferential direction of the inner tube 20. By providing a plurality of protrusions 10b on the inner wall surface 10a, and arranging the support frame 31 between two adjacent protrusions 10b, and limiting the support frame 31 by the protrusions 10b, it is possible to avoid the support frame 31 from shaking or shifting between the outer tube 10 and the inner tube 20, thereby ensuring the connection stability of the support layer 30, and it is also possible to limit the degree of deformation of the support layer 30 due to the compression of the inner tube 20, thereby effectively limiting the expansion of the inner tube 20, and further ensuring that the cooling pressure of the liquid cooling pipeline 100 of the energy storage system 200 is within a reasonable operating range.

[0099] It can be understood that each protrusion 10 b extends along the length direction of the outer tube 10 and is consistent with the extension direction of the support frame 31 .

[0100] Optionally, when the liquid cooling pipeline 100 is a liquid outlet pipe, the support layer 30 can be made of metal, such as aluminum, copper, and other materials with good elasticity and good thermal conductivity. In this way, the temperature of the coolant inside the liquid outlet pipe increases, and the coolant expands to increase the pressure, so that the inner tube 20 expands and contacts the metal support frame 31. Since the inner tube 20 is in direct contact with the coolant, the wall temperature of the inner tube 20 is higher than the support frame 31, and the metal support frame 31 has better heat conduction and heat absorption effects, which is more conducive to the cooling effect of the coolant refluxed to the liquid cooling unit 201.

[0101] When the liquid outlet pipe (liquid return of the liquid cooling unit 201) is in operation, as the ambient temperature rises or the operating load increases (or the operating strategy changes), for example, the internal coolant temperature rises from 18°C ​​to 22°C. Due to the thermal expansion caused by cooling, the pressure of the internal coolant increases, the inner tube 20 expands, the support layer 30 is squeezed by the inner tube 20, and the contact area between the inner tube 20 and the support layer 30 also increases accordingly. The wall temperature of the liquid inlet pipe is higher than that of the support layer 30. The metal support layer 30 conducts and absorbs heat and dissipates the heat into the interlayer air, which can cool the coolant returning to the cooling unit.

[0102] See also Figure 5 and Figure 6, the liquid cooling circuit 100 provided in the embodiment of the present application can also be used as a liquid inlet pipe, and the liquid inlet pipe is configured to be connected between the liquid inlet of the liquid cooling plate and the liquid cooling unit 201. In the liquid inlet pipe, the cavity 301 of the support layer 30 is configured as a closed cavity. It can be understood that the liquid cooling plate is arranged in the battery pack 202, and a flow channel for the flow of coolant is provided inside the liquid cooling plate. The coolant flowing out of the liquid cooling unit 201 flows through the liquid inlet pipe, enters the flow channel inside the liquid cooling plate through the liquid inlet, and performs heat exchange on the battery. Due to the inlet pressure, when the liquid cooling circuit 100 is used as a liquid outlet pipe, by setting the cavity 301 of the support layer 30 to be semi-closed, the liquid cooling circuit 100 adjusts its shape by relying on the pressure of the internal coolant, and provides sufficient deformation space for the expansion of the inner tube 20.

[0103] When the liquid inlet pipe is in operation, the outlet liquid temperature is usually 2°C-3°C lower than the return liquid temperature. The pressure of the liquid inlet pipe (i.e. the outlet liquid of the liquid cooling unit 201) is higher than the pressure of the liquid outlet pipe (i.e. the return liquid of the liquid cooling unit 201) and requires more insulation.

[0104] In some possible implementations, the support layer 30 includes a plurality of support tubes 32, which are connected to each other along the circumference of the inner tube 20, each support tube 32 extends along the length direction of the inner tube 20, and at least part of the support tubes 32 are closed in their own circumference to form the cavity 301. That is, the support tubes 32 are closed in their own circumference, and the cavity 301 of the support tubes 32 can serve as an air layer.

[0105] When the liquid cooling pipe 100 is a liquid inlet pipe, by setting the support layer 30 as a plurality of support tubes 32 containing air, the support layer 30 has good support properties, which can reduce the expansion of the inner tube 20. In addition, due to the large thermal resistance of air, it can also effectively delay the leakage of the coolant at a lower temperature in the inner tube 20 to the outer tube 10, thereby helping to improve the thermal insulation capacity of the liquid cooling pipe 100. Compared with the method of providing a layer of EPDM (EthylenePropylene Diene Monomer) insulation cotton on the outside of the liquid cooling pipe 100 in the related art to achieve thermal insulation, the liquid cooling pipe 100 of the embodiment of the present application can eliminate the outermost layer of insulation cotton, which can reduce costs.

[0106] In some possible implementations, the cross-sectional shape of the support tube 32 is circular. By setting the cross-sectional shape of the support tube 32 to be circular and combining the air layer with high thermal resistance inside, the support layer 30 has a better support effect.

[0107] It can be understood that the circular cross-sectional shape of the support tube 32 is the cross-sectional shape under normal operating conditions. When the support tube 32 is squeezed by the inner tube 20 due to changes in the pressure in the inner tube 20, the cross-sectional shape of the support tube 32 will change, for example, it may become an ellipse.

[0108] In some possible implementations, both ends of the support tube 32 are configured as closed ends. That is, the support layer 30 is a sealed tube containing air inside. This configuration enables the sealed support tube 32 to undergo good elastic deformation when subjected to the expansion of the inner tube 20, and to recover to its original shape without permanent deformation when the inner tube 20 retracts, and is more conducive to maintaining good performance within a temperature range of -40°C to 120°C.

[0109] In some possible implementations, when the liquid cooling circuit 100 is a liquid inlet pipe, the support layer 30 is made of plastic. By using a support tube 32 made of plastic material, the elastic deformation performance and the ability of the support tube 32 to rebound and return to its original state are guaranteed on the premise that it can have good support. In addition, the support tube made of plastic material has a low thermal conductivity and good thermal insulation performance, which can effectively prevent the transfer of heat and improve the thermal insulation performance of the liquid cooling circuit 100 when it is used as a liquid inlet pipe, thereby facilitating the optimization of the heat dissipation effect of the coolant on the battery pack 202.

[0110] It is worth noting that when the liquid inlet pipe is in normal operation, that is, when the liquid inlet pipe is not deformed, the support tube 32 between the outer tube 10 and the inner tube 20 is circular, and a triangular air gap 302 is formed between the support layer 30 and the inner tube 20 and the outer tube 10. The contact area between the support layer 30 and the inner tube 20 and the outer tube 10 is small. At this time, the main heat transfer mode of the liquid inlet pipe is: most of the heat is transferred through air convection, and a small part is transferred through the contact between the support tube 32 and the inner tube 20 and the outer tube 10. When the outlet pressure increases, the coolant pressure inside the liquid inlet pipe increases, the inner tube 20 expands, the support layer 30 is squeezed, the air gap 302 between the support tube 32 and the inner tube 20 and the outer tube 10 is reduced, and the contact area between the support layer 30 and the inner tube 20 and the outer tube 10 becomes larger. At this time, the main heat transfer mode of the liquid inlet pipe becomes: most of the heat is transferred through the contact between the support tube 32 and the inner tube 20 and the outer tube 10, and a small part is transferred through air convection.

[0111] When the liquid inlet pipe is in operation (liquid is discharged from the liquid cooling unit 201), the support layer 30 adopts a support tube 32 made of plastic material, and the internal cavity 301 contains air and is sealed at both ends. When the liquid outlet pressure increases, the inner tube 20 expands and squeezes the support tube 32, and the contact area between the inner tube 20 and the support tube 32 becomes larger. The air gap 302 between the support tube 32 and the inner tube 20 and between the support tube 32 and the outer tube 10 becomes smaller. The original heat transfer mode of mostly convective heat exchange plus a small part of heat conduction is changed to a heat transfer mode of mostly heat conduction plus a small part of convective heat transfer. The air layer contained in the support tube 32 has a higher thermal resistance and is circular in shape with good support. It can not only reduce the expansion effect of the inner tube 20, but also effectively delay the leakage of relatively low-temperature coolant from the inner tube 20 to the outer tube 10, thereby improving the thermal insulation capacity of the liquid cooling pipeline 100.

[0112] In the energy storage system 200 of the embodiment of the present application, when the liquid cooling pipeline 100 as the liquid inlet pipe is affected by the ambient temperature, the coolant expands or contracts due to the heat. Specifically, when the ambient temperature rises, the coolant inside the liquid cooling pipeline 100 expands due to the heat, and the inner tube 20 expands and squeezes the plastic tube. Since the support tube 32 contains air inside that can be compressed, it can absorb part of the expansion of the coolant. When the ambient temperature drops, the coolant inside the liquid cooling pipeline 100 contracts due to the cold, the liquid pressure decreases, and the inner tube 20 rebounds, which can maintain the liquid pressure or reduce the drop.

[0113] Second, see Figure 7 The present application also discloses an energy storage system 200, including a liquid cooling unit 201, a battery pack 202, and a liquid cooling circuit 100 as described in the first aspect above, wherein the battery pack 202 and the liquid cooling unit 201 are connected via the liquid cooling circuit 100. Among them, the battery pack 202 may include a battery and a liquid cooling plate (not shown), and the liquid cooling plate is configured to dissipate heat from the battery. Specifically, the liquid cooling plate has a liquid inlet and a liquid outlet, and the liquid outlet of the liquid cooling plate is connected to the liquid cooling unit 201 via the liquid cooling circuit 100. At this time, the liquid cooling circuit 100 serves as a liquid outlet of the battery pack 202. The liquid inlet of the liquid cooling plate is also connected to the liquid cooling unit 201 via the liquid cooling circuit 100. At this time, the liquid cooling circuit 100 serves as a liquid inlet of the battery pack 202.

[0114] It can be understood that the energy storage system 200 having the above-mentioned liquid cooling pipeline 100 also has all the technical effects of the above-mentioned liquid cooling pipeline 100. That is, the shape of the liquid cooling pipeline 100 can be adjusted by relying on the change in the pressure of the coolant inside the liquid cooling pipeline 100 to achieve pressure regulation of the energy storage system 200, without occupying additional internal space of the liquid cooling unit 201, and without reducing the flow in the liquid cooling plate. Since the above-mentioned technical effects have been described in detail in the embodiment of the liquid cooling pipeline 100, they will not be repeated here.

[0115] Continue reading Figure 7In some possible implementations, the liquid cooling unit 201 includes an expansion tank 2011, which is connected to the liquid outlet of the battery pack 202 through the liquid cooling pipeline 100, and is used to adjust the pressure of the coolant in the liquid cooling pipeline 100. Specifically, the liquid cooling pipeline 100 is a liquid outlet pipe, that is, the expansion tank 2011 is connected to the liquid outlet pipeline of the battery pack 202 (the liquid return pipeline of the liquid cooling unit 201). On the basis that the liquid cooling pipeline 100 is deformed by the change of the internal coolant pressure to achieve the pressure regulation of the liquid cooling pipeline 100, the expansion tank 2011 is combined to provide additional pressure to the energy storage system 200 or reduce the pressure, so as to further improve the tolerance capacity of the energy storage system 200, thereby ensuring the safe operation of the energy storage system 200.

[0116] The liquid cooling unit 201 may include a refrigeration cycle module and a water circulation module, wherein the refrigeration cycle module may include a compressor, a plate heat exchanger 2012, a condenser, etc. When the refrigeration cycle module is running, a low-temperature and low-pressure refrigerant enters the compressor, and the compressor compresses the refrigerant gas into a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The plate heat exchanger 2012 (used as an evaporator) can exchange heat with the coolant. The water circulation module may include a water pump and the expansion tank 2011 described above. The water pump can drive the coolant to flow.

[0117] Exemplarily, the expansion tank 2011 is connected to the coolant input end of the water pump, the plate heat exchanger 2012 is connected to the coolant output end of the water pump, and then connected to the liquid inlet of the liquid cooling plate. The coolant can be pressurized by the water pump into the plate heat exchanger 2012 for heat exchange, so that after the coolant is cooled, the coolant is transported to the liquid cooling plate through the liquid cooling pipeline 100, heat exchanges with the battery, and adjusts the temperature of the battery. The coolant after heat exchange flows back to the water pump through the liquid cooling pipeline 100 to form a cycle.

[0118] In some possible implementations, the expansion tank 2011 includes a liquid storage chamber 2011a and an air storage chamber 2011b, wherein the liquid storage chamber 2011a is used to be filled with coolant, and the air storage chamber 2011b is used to be filled with gas, and the air storage chamber 2011b is connected to the support layer 30 of the liquid cooling pipeline 100. The liquid cooling unit 201 also includes an air pump 2013 and a shut-off valve 2014, wherein the shut-off valve 2014 is connected between the air pump 2013 and the air storage chamber 2011b, and the air storage chamber 2011b is configured to realize pressure charging or pressure relief under the action of the shut-off valve 2014 and the air pump 2013, so as to adjust the pressure of the coolant in the liquid cooling pipeline 100.

[0119] By adding an air pump 2013 and a shut-off valve 2014 to the refrigeration unit, and connecting the air storage chamber 2011b of the expansion tank 2011 to the support layer 30 of the liquid cooling pipeline 100, when the pressure in the liquid cooling pipeline 100 is too high, the pressure in the air storage chamber 2011b of the expansion tank 2011 can be reduced by opening the shut-off valve 2014. Due to the pressure difference, the coolant in the liquid cooling pipeline 100 will enter the liquid storage chamber 2011a of the expansion tank 2011 to accommodate more coolant. At the same time, since the support layer 30 of the liquid cooling pipeline 100 is connected to the air storage chamber 2011b, the pressure of the interlayer between the outer tube 10 and the inner tube 20 is reduced, the pressure of the coolant inside the inner tube 20 is greater than the air pressure of the interlayer, the inner tube 20 expands, and the internal volume of the liquid cooling pipeline 100 increases, so that the pressure of the liquid cooling pipeline 100 is reduced.

[0120] When the pressure in the liquid cooling pipeline 100 is too low, the shut-off valve 2014 and the air pump 2013 can be opened at the same time, and the air pump 2013 can be used to inflate the air storage chamber 2011b of the expansion tank 2011, so that the pressure of the air storage chamber 2011b increases. At this time, since the pressure of the liquid storage chamber 2011a is lower than the pressure of the air storage chamber 2011b, the coolant in the liquid storage chamber 2011a is squeezed into the pipeline of the energy storage system 200. At the same time, since the support layer 30 of the liquid cooling pipeline 100 is connected to the air storage chamber 2011b, the pressure of the interlayer between the outer tube 10 and the inner tube 20 increases, the pressure of the coolant inside the inner tube 20 is lower than the air pressure of the interlayer, the inner tube 20 contracts, and the internal volume of the liquid cooling pipeline 100 becomes smaller, so that the pressure of the liquid cooling pipeline 100 increases.

[0121] It should be noted that the above-mentioned liquid cooling pipeline 100 is a liquid storage pipe, that is, a liquid outlet pipe of the battery pack 202 (a pipeline connected between the liquid outlet of the battery pack 202 and the liquid cooling unit 201 for returning liquid to the liquid cooling unit 201). In addition, the support layer 30 is not completely closed, and there is an air gap 302 between the support layer 30 and the outer tube 10 and the inner tube 20, and the air storage chamber 2011b of the expansion tank 2011 is connected to the air gap 302.

[0122] In the third aspect, the present application also discloses an energy storage system 200, comprising a liquid cooling unit 201, a battery pack 202 and a liquid cooling pipeline 100 according to the first aspect of the claim, the liquid cooling plate and the liquid cooling unit 201 are connected through the liquid cooling pipeline 100, the liquid cooling unit 201 comprises an expansion tank 2011, a detection device and a control device (not shown), the expansion tank 2011 is arranged on the liquid outlet pipeline of the battery pack 202, and the air storage chamber 2011b of the expansion tank 2011 is connected to the support layer 30 of the liquid cooling pipeline 100, the detection device is used to detect the return liquid pressure of the liquid cooling unit 201, and the control device is used to control the expansion tank 2011 to adjust the pressure of the coolant in the liquid cooling pipeline 100 according to the return liquid pressure of the liquid cooling unit 201. With such an arrangement, the return liquid pressure of the liquid cooling unit 201 can be detected by the detection device. When the pressure in the liquid cooling pipeline 100 is too high or too low, the expansion tank 2011 is controlled by the control device to adjust the pressure of the coolant in the liquid cooling pipeline 100, thereby realizing active adjustment of the pressure of the energy storage system 200.

[0123] Fourthly, see Figure 8 The present application also discloses a pressure control method of an energy storage system 200, wherein the energy storage system 200 is the energy storage system 200 of the third aspect, and the method comprises:

[0124] 101. The control detection device detects the return liquid pressure of the liquid cooling unit;

[0125] Optionally, the detection device can be arranged on the liquid cooling pipe 100 between the liquid cooling unit 201 and the liquid outlet of the battery pack 202, that is, the liquid outlet pipe of the liquid cooling pipe 100 at this time. The specific structure of the liquid outlet pipe can refer to the structure of the liquid cooling pipe 100 as the liquid outlet pipe, which will not be described in detail here.

[0126] 102. According to the return liquid pressure of the liquid cooling unit, control the expansion tank to adjust the pressure of the coolant in the liquid cooling pipeline.

[0127] In some possible implementations, the liquid cooling unit 201 further includes an air pump 2013 and a shutoff valve 2014, the shutoff valve 2014 is connected between the air pump 2013 and the air storage chamber 2011b of the expansion tank 2011, and the air storage chamber 2011b is also connected to the support layer 30 of the liquid cooling pipeline 100. Specifically, the air storage chamber 2011b is connected to the air gap 302 in the support layer 30. The above step 102 also includes:

[0128] 201. When the return liquid pressure exceeds the upper limit of the preset range, the shut-off valve 2014 is controlled to open by the control device, and the pressure of the air storage chamber 2011b is reduced;

[0129] 202. When the return liquid pressure is lower than the lower limit of the preset range, the control device controls the shut-off valve 2014 and the air pump 2013 to open completely, and controls the air pump 2013 to inflate the air storage chamber 2011b.

[0130] Exemplarily, the liquid cooling unit 201 monitors whether the return liquid pressure range of the liquid cooling unit 201 is between 1.0 bar and 1.5 bar. When the liquid pressure exceeds 1.5 bar, the shut-off valve 2014 is opened to reduce the pressure in the air storage chamber 2011b of the expansion tank 2011. Due to the pressure difference, the coolant in the liquid cooling pipeline 100 will enter the liquid storage chamber 2011a of the expansion tank 2011 to accommodate more coolant. At the same time, since the support layer 30 of the liquid cooling pipeline 100 is connected to the air storage chamber 2011b, the pressure of the interlayer between the outer tube 10 and the inner tube 20 is reduced, the pressure of the coolant inside the inner tube 20 is greater than the air pressure of the interlayer, the inner tube 20 expands, and the internal volume of the liquid cooling pipeline 100 increases, so that the pressure of the liquid cooling pipeline 100 is reduced.

[0131] It should be noted that the shut-off valve 2014 needs to be opened slightly to prevent the air from being released too quickly.

[0132] When the liquid pressure is lower than 1 bar, the air pump 2013 is turned on and the shut-off valve 2014 is fully opened, and the air pump 2013 is used to inflate the air storage chamber 2011b of the expansion tank 2011, and the pressure of the air storage chamber 2011b increases. At this time, since the pressure of the liquid storage chamber 2011a is lower than the pressure of the air storage chamber 2011b, the coolant in the liquid storage chamber 2011a is squeezed into the pipeline of the energy storage system 200. At the same time, since the support layer 30 of the liquid cooling pipeline 100 is connected to the air storage chamber 2011b, the pressure of the interlayer between the outer tube 10 and the inner tube 20 increases, the pressure of the coolant inside the inner tube 20 is lower than the air pressure of the interlayer, the inner tube 20 contracts, and the internal volume of the liquid cooling pipeline 100 becomes smaller, so that the pressure of the liquid cooling pipeline 100 increases.

[0133] The liquid cooling pipeline, energy storage system and pressure control method thereof disclosed in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the liquid cooling pipeline, energy storage system and pressure control method thereof and their core ideas of the present application; at the same time, for general technicians in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A liquid cooling pipeline, characterized in that: include: External pipe; an inner tube, the inner tube being arranged inside the outer tube, the inner tube being spaced apart from the outer tube in a radial direction of the outer tube, the inner tube being used to be filled with a coolant, and the inner tube being configured to expand or contract when the pressure of the coolant changes; and A support layer is provided between the outer tube and the inner tube and surrounds the inner tube. At least a portion of the support layer abuts against an inner wall surface of the outer tube and an outer wall surface of the inner tube. The support layer is configured to be deformable when the inner tube expands or contracts.

2. The liquid cooling pipeline according to claim 1, characterized in that: The support layer is formed with a cavity, the extension length of the cavity is consistent with the extension length of the inner tube, and the cavity is configured to provide a space for the support layer to deform.

3. The liquid cooling pipeline according to claim 2, characterized in that: The cavity of the supporting layer has a first opening, and the inner wall surface and / or the outer wall surface closes the first opening.

4. The liquid cooling pipeline according to claim 3, characterized in that: The support layer has a first curved surface and a second curved surface arranged opposite to each other, the first curved surface is configured as a side close to the inner wall surface, and the second curved surface is configured as a side away from the inner wall surface, and the first curved surface and the second curved surface both protrude toward the outer wall surface so that the support layer constructs the first opening facing the inner wall surface, the cavity is formed between the first curved surface and the inner wall surface, and the second curved surface abuts against the outer wall surface.

5. The liquid cooling pipeline according to claim 4, characterized in that: The support layer includes a plurality of support frames, and the plurality of support frames are interconnected along the circumferential direction of the inner tube. Each of the support frames extends along the length direction of the inner tube, and at least some of the support frames have the first arcuate surface and the second arcuate surface arranged opposite to each other, so that at least some of the support frames construct the first opening facing the inner wall surface.

6. The liquid cooling pipeline according to claim 5, characterized in that: A plurality of protrusions are provided on the inner wall surface, and the plurality of protrusions are spaced apart along the circumference of the inner tube. Both sides of each support frame abut between two adjacent protrusions, and the protrusions are configured to limit the position of the support frame on the circumference of the inner tube.

7. The liquid cooling pipeline according to claim 2, characterized in that: The support layer includes a plurality of support tubes, which are connected to each other along the circumferential direction of the inner tube. Each support tube extends along the length direction of the inner tube, and at least part of the support tubes are closed in their own circumferential direction to form the cavity.

8. The liquid cooling pipeline according to claim 7, characterized in that: The cross-sectional shape of the support tube is circular, and / or both ends of the support tube are configured as closed ends.

9. The liquid cooling pipeline according to any one of claims 2 to 6, characterized in that: The liquid cooling pipeline is a liquid outlet pipe, and the liquid outlet pipe is configured to be connected between the liquid outlet of the liquid cooling plate and the liquid cooling unit. In the liquid outlet pipe, the cavity of the support layer has a first opening.

10. The liquid cooling pipeline according to any one of claims 2, 7 and 8, characterized in that: The liquid cooling pipeline is a liquid inlet pipe, and the liquid inlet pipe is configured to be connected between the liquid inlet of the liquid cooling plate and the liquid cooling unit. In the liquid inlet pipe, the cavity of the support layer is configured as a closed cavity.

11. The liquid cooling pipeline according to claim 1, characterized in that: When the liquid cooling pipeline is used as a liquid outlet pipe, the support layer is made of metal; When the liquid cooling pipeline is used as a liquid inlet pipe, the supporting layer is made of plastic material.

12. The liquid cooling pipeline according to claim 1, characterized in that: The thickness of the outer tube is 1 mm to 1.25 mm, and / or the thickness of the inner tube is 1 mm to 1.25 mm.

13. An energy storage system, characterized in that: It comprises a liquid cooling unit, a battery pack and a liquid cooling pipeline as described in any one of claims 1 to 12, wherein the battery pack and the liquid cooling unit are connected through the liquid cooling pipeline.

14. The energy storage system according to claim 13, characterized in that: The liquid cooling unit includes an expansion tank, which is connected to the liquid outlet of the battery pack through the liquid cooling pipeline and is used to adjust the pressure of the coolant in the liquid cooling pipeline.

15. The energy storage system according to claim 14, characterized in that: The expansion tank comprises a liquid storage chamber and an air storage chamber, the liquid storage chamber is used to be filled with coolant, the air storage chamber is used to be filled with gas, and the air storage chamber is connected to the support layer of the liquid cooling pipeline; The liquid cooling unit also includes an air pump and a shut-off valve, wherein the shut-off valve is connected between the air pump and the air storage chamber, and the air storage chamber is configured to be pressurized or depressurized under the action of the shut-off valve and the air pump to adjust the pressure of the coolant in the liquid cooling pipeline.

16. An energy storage system, characterized in that: It includes a liquid cooling unit, a battery pack and a liquid cooling pipeline as described in any one of claims 1 to 12, the battery pack and the liquid cooling unit are connected through the liquid cooling pipeline, the liquid cooling unit includes an expansion tank, a detection device and a control device, the expansion tank is arranged on the liquid outlet pipeline of the battery pack, and the air storage chamber of the expansion tank is connected to the supporting layer of the liquid cooling pipeline, the detection device is used to detect the return liquid pressure of the liquid cooling unit, and the control device is used to control the expansion tank to adjust the pressure of the coolant in the liquid cooling pipeline according to the return liquid pressure of the liquid cooling unit.

17. A pressure control method for an energy storage system, characterized in that: The energy storage system is the energy storage system according to claim 16, and the method comprises: Controlling the detection device to detect the liquid return pressure of the liquid cooling unit; According to the return liquid pressure of the liquid cooling unit, the expansion tank is controlled to adjust the pressure of the coolant in the liquid cooling pipeline.

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