System for cooling object

Abstract

A system (1) for cooling an object (3), the system (1) comprising:-a housing (4) within which a volume is arranged so as to receive said object (3) at a distance from a base (5) of the housing (4); a heat exchanger (11), in particular a condenser, arranged inside the housing (4), in particular above the object (3); -at least one plate (50) which extends at least partially towards the surface of the object (3) and which can be arranged vertically or substantially vertically, in which a phase change material (23), in particular a dielectric, is intended to occupy the free volume within the housing (4), in particular between the base (5) of the housing (4) and the object (3).

Description

Technical Field

[0001] This invention relates to a system for cooling an object. It also relates to a battery comprising such a system and an object, the object being, for example, at least one battery module. Furthermore, the invention relates to a vehicle, particularly a motor vehicle, comprising such a system or such a battery. Background Technology

[0002] Electric or hybrid motor vehicles include traction and / or propulsion batteries. These batteries comprise modules, each containing multiple electrochemical cells for storing electrical energy. Cooling these cells is considered important to maximize battery life and charging speed, particularly due to the increased thermal power density of these batteries.

[0003] A cooling system is known that provides cooling by circulating a heat transfer fluid (such as water glycol). However, this solution has drawbacks. In particular, the safety requirements of the system, due to water being a good electrical conductor, complicate its implementation. Summary of the Invention

[0004] The object of this invention is to provide a system for cooling objects that overcomes the aforementioned drawbacks and improves upon systems known from the prior art. In particular, this invention enables the realization of a simple, reliable system with optimized cooling performance.

[0005] This invention relates to a system for cooling an object, the system comprising:

[0006] - A housing, the volume of which is arranged within the housing so as to receive the object at a certain distance from the base of the housing;

[0007] - A heat exchanger, particularly a condenser, arranged within the housing, particularly above the object;

[0008] - At least one plate, which extends at least partially toward the surface of the object and can be arranged vertically or substantially vertically.

[0009] In particular, the phase change material of the dielectric is intended to occupy the free volume within the housing, especially between the base of the housing and the object.

[0010] The system may include at least one channel that extends vertically or substantially vertically.

[0011] The at least one plate may have a crenellated profile.

[0012] The at least one plate may have:

[0013] - A profile that can provide mechanical elasticity to the assembly formed by the object and the at least one plate; and / or

[0014] - Thickness between 2 mm and 5 mm.

[0015] The system may include at least one plate, particularly a first plate and a second plate, arranged to face the outer surface of the object, the first plate and the second plate being arranged to face a first longitudinal outer surface of the object and a second longitudinal outer surface of the object on the side opposite to the first longitudinal outer surface, respectively.

[0016] The object may include at least one battery module, which includes at least two energy storage elements, and the system includes at least one plate arranged between two adjacent energy storage elements, particularly at the center of the module.

[0017] The system may include at least one elongated support member arranged within the housing, particularly laterally between the base of the housing and the object.

[0018] The system may include at least one movable diaphragm disposed within the housing and between the object’s lateral outer surface and the housing.

[0019] The present invention also relates to a battery comprising the system and object as defined above, the object being, for example, at least one battery module.

[0020] The present invention also relates to a vehicle, particularly a motor vehicle, which includes the system as defined above and / or the battery as defined above. Attached Figure Description

[0021] The accompanying drawings illustrate, by way of example, embodiments of a system for cooling objects according to the present invention.

[0022] Figure 1 This is a cross-sectional view along the vertical plane AA, showing an embodiment of a system for cooling an object.

[0023] Figure 2 This is a cross-sectional view along the horizontal plane BB, showing an embodiment of a system for cooling an object.

[0024] Figure 3 This is a cross-sectional view along the vertical plane CC, showing an embodiment of a system for cooling an object. Detailed Implementation

[0025] An orthogonal reference system X, Y, Z is defined, where X represents the longitudinal direction, Y represents the transverse direction, and Z represents the vertical or approximately vertical direction. The terms "above," "upper," "top," "lower," "bottom," and "base" are defined with reference to the Z-axis oriented from bottom to top.

[0026] To cool battery cells, particularly those used in vehicles, one solution is to immerse the cells in a dielectric phase change material contained within the casing. The liquid phase of the dielectric material, in contact with the hot cell, evaporates, thus cooling the cell. The gaseous phase of the dielectric material then condenses on a wall known as the "cold" wall (which has a low temperature) and flows downwards within the casing. This solution allows for cooling of the top and sides of the cell via thermal conduction. The heat generated within the cell is transferred to the cooled top and sides of the cell.

[0027] This solution enables heat exchange between the cell and the high-performance dielectric phase change material. Therefore, the thermal conductivity resistance within the cell dominates the total thermal resistance of the system, which is the sum of the thermal conductivity resistance within the cell and the thermal exchange resistance between the dielectric material and the wall.

[0028] In order to improve the cooling performance of such a system, the applicant has sought to reduce the thermal resistance of the cell.

[0029] This invention proposes a system that cools not only the top and two side wings or sides of the battery cell, but also the bottom or lower surface of the battery cell. Typically, the lower surface of the battery cell is in contact with the base of the casing, thus preventing the lower surface of the battery cell from being cooled. This invention proposes a system that enables the cooling of all four side surfaces of an object, and particularly the lower surface of the object, across its entire thickness.

[0030] The following text is for reference only. Figures 1 to 3 An embodiment of system 1 for cooling object 3 is described.

[0031] Object 3 may include at least one battery module, particularly for vehicle 100. The at least one battery module may be a Li-ion battery.

[0032] Vehicle 100 is, for example, a motor vehicle, particularly an electric or hybrid motor vehicle. Vehicle 100 may be a motor vehicle that includes a combustion engine equipped with a battery, particularly having a voltage of about 48 V.

[0033] System 1 includes a housing 4, with a volume disposed within the housing to receive the object 3. Housing 4 includes a base 5.

[0034] The outer casing 4 is, for example, a parallelepiped or substantially parallelepiped. The outer casing 4 may include a first longitudinal wall 4a and a second longitudinal wall 4b. The first longitudinal wall 4a and the second longitudinal wall 4b are on opposite sides and are parallel or substantially parallel to each other. The first longitudinal wall 4a and the second longitudinal wall 4b are, for example, vertical or substantially vertical.

[0035] If the outer casing 4 is a parallelepiped or substantially parallelepiped, then the outer casing 4 may include a third lateral wall 4c and a fourth lateral wall 4d. The third lateral wall 4c and the fourth lateral wall 4d are on opposite sides and are parallel or substantially parallel to each other. The third lateral wall 4c and the fourth lateral wall 4d are, for example, vertical or substantially vertical.

[0036] Preferably, the first longitudinal wall 4a, the second longitudinal wall 4b, the third lateral wall 4c, the fourth lateral wall 4d, and the base 5 form a parallelepiped or substantially parallelepiped box that is open at the top (without an upper wall).

[0037] In the case of the parallelepiped shell 4, section AA is taken along a plane parallel to or approximately parallel to the longitudinal walls 4a and 4b. Also in the case of the parallelepiped shell 4, section BB is taken along a plane parallel to or approximately parallel to the base 5 of the shell 4. Also in the case of the parallelepiped shell 4, section CC is taken along a plane parallel to or approximately parallel to the lateral walls 4c and 4d.

[0038] Object 3 is intended to be placed inside the outer shell 4 at a certain distance from the base 5 of the outer shell 4.

[0039] Advantageously, the housing 4 includes a cover 16, which is particularly removable. The cover 16 is intended to be positioned on top of the housing 4 so as to close the housing 4 from above.

[0040] In particular, the phase change material 23 of the dielectric is intended to occupy the free volume within the housing 4, especially between the base 5 of the housing 4 and the object 3.

[0041] Material 23 is, for example, a material having a boiling point of about 34°C.

[0042] Material 23 may be a pure material, for example. In a variant, material 23 may be an oil-based mixture.

[0043] Depending on temperature and / or pressure conditions, material 23 can change from a liquid phase to a gas phase, and vice versa. Preferably, material 23 is dielectric.

[0044] The at least one battery module may include at least one energy storage element 6, particularly at least one electrochemical cell.

[0045] The at least one energy storage element 6 is specifically immersed in material 23.

[0046] The at least one energy storage element 6 is, for example, an electrochemical pouch cell.

[0047] The at least one energy storage element 6 includes a main portion 7, which is particularly rectangular, and an energy storage material is located in the main portion. The at least one energy storage element 6 further includes positive and negative electrical connections 8 and 9.

[0048] The height H of object 3 or the at least one energy storage element 6 should be understood as the dimension of object 3 or main part 7 in the Z direction. The width W of object 3 or the at least one energy storage element 6 should be understood as the dimension of object 3 or main part 7 in the X direction.

[0049] For example, regarding the order of magnitude of the size, the height H of the at least one energy storage element 6 is, for example, between 80 mm and 100 mm.

[0050] Each energy storage element 6 includes a first main surface 7a and a second main surface 7b. The first surface 7a and the second surface 7b are on opposite sides and are parallel or substantially parallel to each other. The energy storage element 6 is positioned within the housing 4 such that the first surface 7a of each energy storage element 6 faces the first longitudinal wall 4a of the housing 4, and the second surface 7b of each energy storage element 6 faces the second longitudinal wall 4b of the housing 4.

[0051] Advantageously, the main part 7 of each energy storage element 6 is a parallelepiped. Preferably, all energy storage elements 6 have the same or substantially the same size and are arranged side by side.

[0052] The energy storage element 6 is arranged vertically, with its main surfaces in contact with each other.

[0053] System 1 may include at least one elongated support member 30, which is arranged within the housing 4, particularly laterally, between the base 5 of the housing 4 and the object 3. Advantageously, system 1 may include multiple elongated support members 30. The elongated support members 30 may be arranged at a distance from each other along the X direction.

[0054] The at least one elongated support member 30 is arranged particularly along the Y direction.

[0055] The at least one elongated support member 30 is, for example, a crossbeam.

[0056] The at least one elongated support member 30 is made of, for example, plastic.

[0057] The at least one elongated support member 30 can be placed on the base 5 of the housing 4. The object 3, in particular the energy storage element 6, can be placed on the at least one elongated support member 30.

[0058] With the aid of at least one elongated support 30, the main part 7 of the energy storage element 6 is raised relative to the base 5 of the housing 4. The energy storage element 6 is thus closer to the condenser 11.

[0059] The at least one elongated support 30 allows the phase change material 23 to pass between the lower surface 3c of the object 3 and the base 5 of the shell 4.

[0060] Material 23 occupies (fills) the available volume V below, above, and / or around object 3. Material 23 occupies (fills) the available volume V below, above, and / or around energy storage element 6. Volume V extends particularly below energy storage element 6, i.e., between the base 5 of housing 4 and energy storage element 6.

[0061] Each energy storage element 6 includes a lower surface 7c and an upper surface 7d.

[0062] The distance between the base 5 of the outer casing 4 and the lower surface 7c of the energy storage element 6 is called the height e.

[0063] Height e corresponds to, for example, 15% of height H.

[0064] System 1 may include a heat exchanger 11, particularly a condenser.

[0065] The condenser 11 can be arranged inside the housing 4, preferably in the upper part of the housing 4, for example above the object 3, especially just above the energy storage element 6.

[0066] Advantageously, the condenser 11 may include fins.

[0067] Preferably, one or more pipes or tubes 12 may extend within the condenser 11. These pipes 12 allow liquid (e.g., a liquid intended to cool the condenser 11, such as an aqueous liquid) to circulate. The system 1 may include an inlet / outlet 13 for at least one liquid.

[0068] System 1 may include a perforated separation device 14, particularly a grille or substantially a grille. The perforated separation device 14 may be arranged between the object 3 and the condenser 11, particularly between the upper surface 7d of the energy storage element 6 and the condenser 11. The perforated separation device 14 particularly includes walls extending vertically or substantially vertically, advantageously extending over the entire thickness of the perforated separation device. Thus, the walls create openings between them to allow the phase change material 23 to be transferred from the upper surface 7d of the energy storage element 6 to the condenser 11 and vice versa. The perforated separation device 14 is particularly designed to reduce the height of system 1 to retain the phase change fluid 23, even when the vehicle tilt is not negligible. However, the perforated separation device 14 is made as thin as possible to reduce the overall size of system 1, allowing the condenser 11 to be as close as possible to the energy storage element 6, wherein only the perforated separation device 14 is inserted between the upper surface 7d of the energy storage element 6 and the condenser 11. The minimum distance between the upper surface 7d of the energy storage element 6 and the condenser 11 is selected, particularly to ensure proper boiling of the phase change material 23. The distance between the cover 16 and the upper surface 7d of the energy storage element 6 is specifically selected to ensure sufficient space for the condenser 11. The distance between the cover 16 and the upper surface 7d of the energy storage element 6 is, for example, about 10 mm.

[0069] The thickness of the perforation separation device 14 should be understood as its dimension in the Z direction.

[0070] The perforation separation device 14 has a thickness, for example, between 0.5 mm and 5 mm, and particularly between 1 mm and 3 mm.

[0071] System 1 may include at least one diaphragm 43, 44, which is particularly movable and arranged within the housing 4, between the lateral outer surface of the object 3 and the housing 4.

[0072] The housing 4 may include three regions: a central region 40 and a first end region 41 and a second end region 42 located at opposite ends of the housing 4 in the X direction. The central region 40 and the first end region 41 can be separated by a first diaphragm 43. The central region 40 and the second end region 42 can be separated by a second diaphragm 44. Advantageously, the first diaphragm 43 is movable. Advantageously, the second diaphragm 44 is movable.

[0073] The movable diaphragms 43 and 44 enable variable volumes of the first end region 41 and the second end region 42, thereby minimizing the volume of the phase change material 23 and compensating for changes in the volume of the cooling fluid.

[0074] The movable diaphragms 43 and 44 are designed to stabilize the pressure within the housing 4.

[0075] The liquid-to-vapor transition increases the volume occupied by the phase change material 23. Two diaphragms 43 and 44 move toward the side walls 4c and 4d of the housing 4, respectively. During boiling, the pressure in the central region 40 of the housing 4 remains at atmospheric pressure. The movable diaphragms 43 and 44 enable the maintenance of a pressure equal to or approximately equal to atmospheric pressure during operation of the system 1.

[0076] System 1 may include at least one opening 10 located in at least one of the lateral walls 4c and 4d of the housing 4. System 1 may include one opening 10 located in the third lateral wall 4c and one opening 10 located in the fourth lateral wall 4d. The at least one opening 10 is designed to allow external air to enter the housing 4 when the volume of the dielectric fluid decreases and to allow air to leave to the outside when the volume increases. The opening 10 is designed to allow air to enter or leave the end regions 41 and 42 of the housing 4. The at least one opening 10 is designed to ensure a constant or substantially constant pressure in the housing 4, particularly equal to or substantially equal to atmospheric pressure. The phase change material 23 can therefore boil at atmospheric pressure.

[0077] System 1 may include a hole formed at a location on the cover 16, the hole being designed to fill the housing 4 with material 23. The hole is designed to be closed by a sealing plug 17.

[0078] System 1 may include a first global electrical connector 15 and a second global electrical connector 19.

[0079] System 1 includes at least one plate 50 that extends at least partially toward the surface of the object 3.

[0080] The at least one plate 50 can be arranged vertically or substantially vertically.

[0081] Advantageously, the at least one plate 50 can extend over the entire height H of the object 3.

[0082] Advantageously, the at least one plate 50 can extend over the entire width W of the object 3.

[0083] The at least one plate 50 is configured to allow the vapor of the phase change material 23 to rise.

[0084] The phase change material 23 is designed to flow downward within the housing 4 when it is in liquid form and to rise within the housing 4 when it is in vapor form.

[0085] The at least one plate 50 makes it easier for material 23 to descend in the liquid phase and / or for material 23 to rise in the gas phase.

[0086] The at least one plate 50 may include at least one channel extending vertically or substantially vertically. The at least one plate 50 may include multiple channels, particularly vertical ones. The at least one plate 50 may be a solid plate perforated with vertical channels.

[0087] At least one vertical channel of the at least one plate 50 allows the vapor of the material 23 generated on the lower surface 7c of the at least one energy storage element 6 to rise toward the condenser 11, and / or allows the liquid of the material 23 formed by condensation to flow downward, thereby cooling the bottom of the at least one energy storage element 6.

[0088] The at least one plate 50 may have a crenellated profile, particularly a rectangular profile. The at least one plate 50 may be made of a thin sheet bent into a shape having a rectangular profile.

[0089] The rectangular profile of the at least one plate 50 is designed to optimize the passage of vapor from the phase change material 23 by increasing the surface area of ​​the at least one plate 50 relative to the flat plate.

[0090] The at least one plate 50 is made of, for example, aluminum or steel. The at least one plate 50 may be made of plastic.

[0091] One or more materials will be selected for the at least one plate 50 to allow the object 3 or the at least one energy storage element 6 to expand.

[0092] The at least one plate 50 may have a thickness between 2 mm and 5 mm. The thickness of the at least one plate 50 should be understood as referring to the distance between the vertical or substantially vertical main surfaces of the at least one plate 50.

[0093] The at least one plate 50 enables the compression of the at least one energy storage element 6.

[0094] The function of the at least one plate 50 can be to provide mechanical elasticity to the object 3, particularly in the case of the energy storage element 6 expanding during the operation of the system 1. The shape of the profile of the at least one plate 50 can be selected to meet this need for mechanical elasticity.

[0095] The at least one plate 50 may have a profile that can provide mechanical elasticity to the assembly formed by the object 3 and the at least one plate 50.

[0096] System 1 may include at least one plate 50 arranged to face the outer surface of object 3.

[0097] System 1 may include a first board 51 and a second board 52.

[0098] The first plate 51 can be arranged to face the first longitudinal outer surface 3a of the object 3. The second plate 52 can be arranged to face the second longitudinal outer surface 3b of the object 3 on the side opposite to the first longitudinal outer surface 3a.

[0099] If object 3 includes at least one battery module comprising at least two energy storage elements 6, then system 1 may include at least one plate 50 arranged around the periphery of the module facing one of the two energy storage elements 6, particularly abutting against a first main surface 7a and / or abutting against a second main surface 7b of the energy storage element 6. System 1 may include two plates 51 and 52 arranged around the periphery of the module facing the two energy storage elements 6 respectively. System 1 may include at least one plate 53 arranged between two adjacent energy storage elements 6, particularly at the center of the module, between the first main surface 7a and the second main surface 7b of the two adjacent energy storage elements 6.

[0100] System 1 may include three boards 51, 52, and 53.

[0101] The gaseous material 23 rises naturally within the outer casing 4. The liquid material 23 flows naturally downward within the outer casing 4. During the liquid-to-gas transition of material 23, its volume increases. The movable diaphragms 43 and 44 enable volume compensation.

[0102] The system 1 of the above type enables cooling of the bottom of the object 3, particularly the bottom of the at least one energy storage element 6. Therefore, all sides of the object 3 can be cooled by boiling the phase change material 23.

[0103] If system 1 can cool only the top and two vertical flanks of object 3, the highest temperature of the at least one energy storage element 6 will be at the bottom and center of the at least one energy storage element 6. By also cooling the bottom of object 3, system 1 of the above type achieves a fourfold reduction in the difference between this highest temperature and the lowest temperature at the surface of object 3 in contact with the phase change material 23.

[0104] One advantage of the system 1 described above is that it enables improved performance of the cooled object 3, particularly the at least one energy storage element 6. This leads to the possibility of ultra-fast charging of the battery including the at least one energy storage element 6. This system 1 also makes it possible to avoid thermal runaway within the battery.

[0105] The direct contact between at least one energy storage element 6 and the phase change material 23 improves the cooling performance of system 1.

[0106] Compared to systems that cool an object only from above, the aforementioned system 1 achieves a fourfold reduction in conductive thermal resistance. This is because, firstly, the length of the thermal path from the at least one energy storage element 6 to the material 23 is halved, and secondly, the heat has two paths along which it dissipates towards the material 23, instead of a single path as in the case of cooling only from above. This makes it possible to significantly reduce the overall thermal resistance of such system 1.

[0107] The number of boards 50 can vary depending on the number of energy storage elements 6 in the module.

[0108] In system 1 of the above type, the greater the number of plates 50, the more uniform the cooling will be.

[0109] The system 1 of the above type may include a single plate 50 at the center of the energy storage element 6, or two plates on each periphery of the module, or if there are a large number of energy storage elements 6, as shown above. Figure 2 The three boards shown are optional. Any other number of boards (50) can be selected.

[0110] Although the invention has been described in the context of batteries used in vehicles, it can be applied to batteries intended to be stationary or within power plants.

[0111] Although the invention has been described in the context of batteries used in motor vehicles, it can be applied to batteries intended to equip any type of vehicle, such as agricultural vehicles, construction machinery, or two-, three-, or four-wheeled vehicles or even aircraft.

[0112] Although the invention has been described in the case of electrochemical pouch cells used for storing electrical energy, the invention is applicable to any type of cell.

[0113] Although the invention has been described in the context of batteries, it is applicable to any type of object that needs to be cooled, such as servers.

Claims

1. A system (1) for cooling an object (3), the system (1) comprising: - a housing (4) inside which a volume is arranged so as to receive said object (3) at a distance from a base (5) of the housing (4); - a heat exchanger (11), in particular a condenser, arranged inside the housing (4), in particular above said object (3); - at least one plate (50) extending at least partially facing a surface of said object (3) and being vertically or substantially vertically arrangeable, wherein a phase-change material (23), in particular dielectric, is intended to occupy a free volume inside the housing (4), in particular between the base (5) of the housing (4) and the object (3).

2. The system of claim 1, wherein, The at least one plate (50) comprises at least one channel extending vertically or substantially vertically.

3. The system of claim 1 or 2, wherein, The at least one plate (50) has a castellated profile.

4. The system of one of the preceding claims, wherein, The at least one plate (50) has: - a profile able to provide mechanical resilience to an assembly formed by the object (3) and the at least one plate (50); and / or - a thickness of between 2 mm and 5 mm.

5. The system of one of the preceding claims, comprising at least one plate (50), in particular a first plate (51) and a second plate (52), arranged facing an outer surface of the object (3), the first plate (51) and the second plate (52) being arranged facing a first longitudinal outer surface (3a) of the object (3) and a second longitudinal outer surface (3b) of the object (3) on a side opposite to the first longitudinal outer surface (3a), respectively.

6. The system of one of the preceding claims, wherein, Said object (3) comprises at least one battery module comprising at least two electrical energy storage elements (6), the system comprising at least one plate (53) arranged between two adjacent electrical energy storage elements (6), in particular in the centre of the module.

7. The system of one of the preceding claims, comprising at least one elongated support (30) arranged inside the housing (4), in particular transversely between the base (5) of the housing (4) and the object (3).

8. The system of one of the preceding claims, comprising at least one movable membrane (43, 44) arranged inside the housing (4) between a lateral outer surface of the object (3) and the housing (4).

9. A battery comprising a system (1) and an object (3) as claimed in one of the preceding claims, the object being for example at least one battery module.

10. A vehicle (100), in particular a motor vehicle, comprising a system (1) as claimed in one of claims 1 to 8 and / or a battery as claimed in claim 9.

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