Thermal conditioning device, in particular device for cooling

Abstract

The invention relates to a thermal conditioning device (1), in particular a device for cooling, for a component that is susceptible to release heat during operation, in particular for an electrochemical energy storage module, comprising a flow-through network (4) for a heat transfer fluid, which network comprises at least one fluid mixing zone (10), at least two separate fluid flows (11) pass through the mixing zone at selected respective angles in order to produce a mixture of a fluid boundary layer and a fluid inner layer in the mixing zone.

Description

Technical Field

[0001] The invention relates to a thermal regulation device, in particular a device for cooling, in particular for electrical components which emit heat during operation, in particular for cooling at least one battery or battery cell of a vehicle, such as a motor vehicle.

[0002] The means of transport may be of land, sea or air type.

[0003] In particular, the present invention relates to a plate heat exchanger designed for the circulation of a heat transfer fluid (e.g. a coolant fluid or a glycol water solution) to achieve the cooling of a hybrid or electric vehicle battery. A first plate or upper plate, which is generally a flat surface, contacts the component to be cooled. A second plate or lower plate, which is a stamped plate, is formed with a circulation channel for the heat transfer fluid. Background Art

[0004] In a known manner, in order to increase the turbulence in the heat transfer fluid (this turbulence having the effect of increasing the exchange coefficient and thus improving the thermal performance), two types of elements can be used.

[0005] First, there are elements known as hard dimples, which are bosses that form the connection between the lower and upper plates. These bosses ensure the mechanical connection of the assembly while ensuring a minimum level of disturbance of the coolant. From a mechanical point of view, these bosses are strong, but the thermal performance is not optimized. In fact, since these bosses pass through the entire height of the flow channel, they cause a significant pressure drop loss, but do not generate enough turbulence to improve thermal performance and thus cannot compensate for this pressure drop loss.

[0006] There are also elements called soft dimples, which are bosses inside the flow channel, but with a lower height, for example recessed from the upper plate. These bosses do not contribute to the mechanical strength of the cooling plate, but are able to ensure significant turbulence in the fluid. Patent application DE102014202161 describes bosses of this type. Summary of the invention

[0007] The object of the present invention is to improve the temperature uniformity of a heat transfer fluid circulating in a circulation network.

[0008] Therefore, the present invention proposes a thermal regulation device, in particular a device for cooling, for a component that can release heat during operation, in particular for an electrochemical energy storage module, which device comprises a circulation network for a heat transfer fluid, which network comprises at least one fluid mixing zone, at least two independent fluid flows leading to the mixing zone according to selected respective angles so as to produce a mixture of a fluid boundary layer and a fluid internal layer in the mixing zone.

[0009] In a network in which a heat transfer fluid circulates, the boundary layer of the fluid at or near a heat exchange wall is heated more than the inner layer of the fluid away from the wall. The inner layer and the boundary layer extend more or less continuously in temperature.

[0010] In the present invention, the temperature gradient within the cross section of the fluid is larger upstream of the mixing zone and smaller in the mixing zone. The purpose of mixing is to reduce or even eliminate this temperature gradient within the fluid.

[0011] The present invention enables efficient mixing of the fluid boundary layer and the fluid interior layer. The above angles are selected so that all layers are mixed. If the angle of incidence between the fluid streams is too small, the layers cannot be effectively mixed because the fluid streams are "too tangential" relative to each other.

[0012] Therefore, the present invention can make the temperature of the fluid uniform over the entire flow cross section (i.e., the flow wall and the flow center). Therefore, the fluid can have a lower temperature at the wall as a thermal interface to perform better heat exchange with the component to be cooled.

[0013] In the present invention, mixing can be performed at relatively low fluid velocities, thanks to the angles chosen for the two streams leading to the mixing zone, and the mixing is of chaotic type. The principle of chaotic mixing is particularly applicable to the mixing of viscous fluids at low speeds. In a known manner, chaotic mixing is based on a "Brownian heat transformation" to achieve the mixing of different fluid layers. For example, according to one way of implementing this transformation, the fluid layers first undergo passive segmentation, then rotate in an elbow with different chirality, and finally recombine to obtain stretching and folding, thereby achieving uniform mixing.

[0014] In the present invention, if the velocity or Reynolds number does not exceed a certain threshold, the mixture is not necessarily turbulent. Therefore, the present invention can achieve mixing at low speed or low Reynolds number, generally Reynolds number Re below 2000, in particular between 100 and 1400. This is particularly advantageous when the heat conditioning device is operated at a fluid velocity that is not sufficient to generate turbulence.

[0015] The present invention enables mixing of fluid layers without incurring excessive pressure drop losses, particularly as opposed to turbulence which is a source of significant pressure drop losses.

[0016] According to one aspect of the invention, the angle of incidence between the two fluid streams leading to the mixing zone is between 45° and 90°, or between 70° and 90°. The angle may be equal to 90°.

[0017] According to one aspect of the present invention, the circulation network comprises:

[0018] - a fluid separation zone designed to separate one fluid flow into two separate flows;

[0019] - A fluid mixing zone, to which the independent fluid flows are directed to achieve mixing.

[0020] Thus, the present invention is able to mix different fluid layers in a mixing zone by separating and then recombining the fluid streams.

[0021] It should be understood that the mixing zone is distinct from the separation zone.

[0022] According to one aspect of the invention, the opening is perpendicular to the general direction of fluid flow in the device.

[0023] According to one aspect of the present invention, the channel and the mixing unit are designed to define at least one separation zone (51), preferably at least two separation zones, wherein the at least one separation zone is designed to separate the fluid flow into at least two independent flows and to define a mixing zone downstream, wherein the two independent flows are mixed in the mixing zone.

[0024] According to one aspect of the invention, the independent flows have parallel sections before rejoining the mixing zone.

[0025] According to one aspect of the invention, the angle of incidence between the two fluid flows leading to the mixing zone is between 45° and 90°, this angle being defined in particular relative to the axis z, ie perpendicular to the axis where the two plates intersect.

[0026] According to the invention, the flows leaving the separation zone and rejoining in the mixing zone are conservative, ie they do not receive any additional fluid flow on the way between the separation zone and the mixing zone.

[0027] According to one aspect of the invention, the sum of the cross-sections of the flows respectively leaving the mixing zone is substantially equal to the cross-section of the mixing zone.

[0028] According to one aspect of the invention, the separation zone comprises an obstacle placed in a channel of the flow network, the obstacle being designed to separate a fluid flow into two flows.

[0029] According to one aspect of the invention, the obstacle extends along the entire height of the passage.

[0030] According to one aspect of the invention, the obstruction is solid, ie the obstruction is distinct from the access to the thermal conditioning device.

[0031] According to one aspect of the invention, the obstacle is of intermittent type, i.e. its size is small relative to the entire fluid circulation network. For example, the size of the obstacle is at most equal to the spacing between two adjacent channels. This type of obstacle is not of large size type, because large size obstacles require multiple channels of the circulation network to follow the bypass bend.

[0032] In a slab structure, the barrier connects the upper and lower slabs.

[0033] According to one aspect of the invention, the obstacle has a polygonal shape, in particular a substantially rectangular or rhombus shape.

[0034] According to one aspect of the invention, the obstacles have a size and shape selected to produce independent flows.

[0035] According to one aspect of the invention, the channel in which the obstacle is placed has side walls whose shape is selected to participate in the separation of the flows and, downstream of the obstacle, in the recombination of the flows in a mixing zone.

[0036] According to one aspect of the invention, the side walls of the channel each have an elbow, in particular an elbow of 45° to 90°, so as to force the independent flow to flow around the obstacle along a bend, in particular a bend of 45° to 90°.

[0037] According to one aspect of the present invention, the angle of the elbow is equal to 90° or 45°, or between 45° and 90°.

[0038] According to one aspect of the invention, the thermal conditioning device comprises a plurality of channels arranged side by side, in particular symmetrical by mutual translation, each channel housing one or more obstacles to achieve separation and recombination of the fluid flows.

[0039] According to one aspect of the invention, two adjacent channels share a common side wall.

[0040] According to one aspect of the invention, a network for fluid circulation includes a fluid flow section downstream of a mixing zone such that fluid flowing in the fluid flow section has a relatively uniform temperature due to mixing in the mixing zone.

[0041] According to one aspect of the invention, the section of the downstream flow has a cross-section for the passage of fluid which is larger, for example 2 times larger, than each cross-section of the independent fluid flows.

[0042] For example, the width of the obstacle is greater than one third or one half of the largest transverse dimension of the downstream section.

[0043] As a variant, the width of the obstacle is greater than the greatest transverse dimension of the downstream section.

[0044] These obstacles thus enable the fluid flow to be separated into two flows, optionally into a laminar flow.

[0045] This differs from prior art, which describes small obstacles (called dimples) placed in a channel to create turbulence without forming independent flows.

[0046] This is also different from the prior art, which proposes separating into serpentine channels from the fluid inlet so that the fluid recombines before reaching the outlet outside the plate. In contrast, in the present invention, when the channels recombined, the fluid that has undergone chaotic mixing is used to cool the area where the component to be cooled is located, and the fluid does not leave the thermal conditioning device without providing useful heat exchange.

[0047] According to one aspect of the invention, the separation zone comprises two channels in which the flow is divided into two flows.

[0048] According to one aspect of the invention, the flow network comprises a plurality of elementary patterns, each elementary pattern being formed by a fluid separation zone and an associated mixing zone.

[0049] According to one aspect of the invention, the elementary patterns are all identical, in particular aligned in parallel rows.

[0050] According to one aspect of the invention, the largest dimension of the pattern is at least 20 times, 15 times, 10 times or 5 times smaller than the largest dimension of the network for fluid circulation.

[0051] In other words, the pattern is small compared to the entire flow network. The pattern is mainly used to homogenize the temperature of the fluid, rather than serving as a cooling interface for the component to be cooled. The pattern or a network outside of these patterns serves as a cooling interface for the component.

[0052] According to one aspect of the invention, the distance between the centers of two consecutive patterns corresponds to the dimensions of the patterns, all these dimensions being measured in the same direction.

[0053] According to one aspect of the invention, a network for fluid circulation includes a fluid flow section downstream of a mixing zone such that fluid flowing in the fluid flow section has a relatively uniform temperature due to mixing in the mixing zone.

[0054] According to one aspect of the invention, the component to be cooled is placed in thermal contact with the downstream section of the mixing zone.

[0055] Optionally, the component does not face the mixing zone. Therefore, the component is cooled by contact with the downstream section of the mixing zone.

[0056] According to one aspect of the invention the length of the mixing zone is shorter, in particular at least 2, 3 or 5 times shorter than the length of the downstream fluid flow section, measured between the fluid inlet and the fluid outlet of the mixing zone and the section respectively.

[0057] The individual streams are relatively close to each other. The spacing is chosen primarily to give the streams to be mixed an angle of incidence, thereby achieving efficient mixing. First, the spacing of the streams is not intended to cover smaller or larger surfaces to be cooled. Therefore, the present invention includes one or more mixing zones on the main fluid cooling path, for example, the path is straight as a whole, in order to homogenize the temperature of the fluid within the main path as much as possible.

[0058] According to one aspect of the invention, the independent fluid flows leading to the mixing zone are arranged in the same plane.

[0059] As a variant, the separate fluid flows leading to the mixing zone are arranged in different planes.

[0060] For example, the network for fluid circulation extends in a main plane, and at least one of the individual flows extends at least partially outside the main plane.

[0061] For example, the heat regulating device includes two independent flow channels, which extend on two different planes, such as two parallel planes, and in particular, one of these channels includes a connecting elbow on another in the channel. Therefore, the heat transfer fluid circulates from one plane to another plane and has at least a portion of the flow, such as perpendicular to these planes. When they converge or recombine, the independent flows meet at an angle that can achieve mixing, such as an angle substantially equal to 90 °. In this example of the present invention, the network for fluid circulation uses the flow direction in three-dimensional space.

[0062] According to one aspect of the invention, exactly two separate flows are recombined in the mixing zone.

[0063] According to one aspect of the present invention, a circulation network is formed between the lower plate and the upper plate.

[0064] According to one aspect of the invention, at least a portion of one of the streams extends in the thickness direction between the two plates.

[0065] According to one aspect of the invention, at least one of the plates comprises a raised area, in particular a punched area, in order to form one or more channels of a network, and / or one or more fluid mixing zones.

[0066] According to one aspect of the invention, both plates comprise raised areas, in particular punched areas, in order to form a network for the fluid circulation together with the mixing fluid zone.

[0067] In another embodiment of the invention, the network for the circulation of fluids comprises one or more tubes in which the heat transfer fluid circulates and the tube or tubes are designed to define one or more zones for mixing the separate flows.

[0068] According to one aspect of the invention, the tube or tubes comprise an obstacle for separating the flows.

[0069] The invention also relates to an assembly comprising a component capable of releasing heat during its operation and a device for thermal regulation as described above, the component being cooled in contact with the device.

[0070] According to one aspect of the invention, the heat transfer fluid is a coolant fluid selected from the group consisting of coolant fluids R134a, R1234yf or R744. As a variant, the heat transfer fluid is an aqueous glycol solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Other characteristics and advantages of the invention will become more apparent from a reading of the following description, provided by way of non-limiting illustration, and the accompanying drawings, in which:

[0072] - [Figure 1] shows schematically and partially a thermal conditioning device;

[0073] - [FIG. 2] schematically and partially illustrates the arrangement of channels and obstacles of a heat conditioning device according to an embodiment of the invention;

[0074] - [Figure 3] schematically and partially shows a cross section of the channel of [Figure 2];

[0075] - [FIG. 4] schematically and partially shows a variant of the regulating device of [FIG. 2];

[0076] - [Figure 5] shows schematically and partially another embodiment of the present invention;

[0077] - [Fig. 6] shows schematically and partially another embodiment of the present invention. DETAILED DESCRIPTION

[0078] Figure 1 shows an assembly 100, which includes a series of battery cells 101 to be cooled, for example, the battery cells 101 are positioned in a plurality of parallel rows, and a thermal conditioning device 1, which is designed to cool the battery cells 101, which are in thermal contact with an upper plate of the cooling device 1, as described below.

[0079] The heat regulating device 1 comprises an upper plate 2 and a lower plate 3, wherein the lower plate 3 is assembled with the upper plate 2 to form a circulation network 4, which is composed of a plurality of channels 5 for circulating a liquid heat transfer fluid, in particular an ethylene glycol aqueous solution, as shown in FIG.

[0080] The flow direction of the fluid in the channel 5 is indicated by arrows F.

[0081] The channel 5 is supplied with fluid via a fluid distribution area (not shown) which communicates with a fluid inlet 7. A fluid outlet 8 is also provided. A flange 9 can be connected to the inlet 7 and the outlet 8 to ensure connection with an external fluid circuit, which mainly comprises a pump.

[0082] The circulation network 4 comprises fluid mixing zones 10 , two independent fluid flows 11 being directed to each zone 10 according to respective angles selected so as to produce mixing of a boundary layer 12 of fluid and an internal layer 14 of fluid in the mixing zones 10 .

[0083] 3, in a network 4 for the circulation of a heat transfer fluid, a boundary layer 12 of the fluid on or near a heat exchange wall 2 is heated more than an inner layer 14 remote from the wall 2. The inner layer 14 and the boundary layer 12 extend in temperature in a continuous manner to each other.

[0084] The temperature gradient within the cross section of the fluid is greater upstream of the mixing zone 10 and is smaller in the mixing zone 10. The purpose of mixing is to reduce or even eliminate this temperature gradient within the fluid.

[0085] The invention thus makes it possible to homogenize the temperature of the fluid over the entire flow cross section, ie the wall 2 and the center of the flow.

[0086] Mixing can be performed at relatively low fluid velocities, thanks to the angles chosen for the two flows leading to the mixing zone, and the mixing is of chaotic type.

[0087] In the example described, the angle of incidence between the two fluid flows 11 leading to the mixing zone 10 is 90°.

[0088] The circulation network 4 will now be described in more detail.

[0089] The flow network 4 comprises a plurality of basic patterns 15 , each basic pattern 15 being formed by a fluid separation zone 16 and a mixing zone 10 associated therewith.

[0090] The fluid separation zone 16 is designed to separate a fluid stream 17 into two separate streams 11 .

[0091] The separate fluid streams 11 pass into a fluid mixing zone 10 where mixing can occur.

[0092] By separating and then recombining the fluid streams, different fluid layers can be mixed in the mixing zone.

[0093] Each separation zone 16 is associated with a separation obstacle 18 placed in the channel 5 of the flow network 4. The obstacle 18 is designed to separate the fluid flow into two flows.

[0094] The obstacle 18 extends over the entire height of the passage 5 .

[0095] Each obstacle 18 connects the lower plate 3 and the upper plate 2 .

[0096] The lower plate 3 comprises a punched area 19 forming the channels 5 of the network 4 and the obstacles 18 associated with the mixing zones 10 .

[0097] In the example depicted in FIG. 2 , the obstacle 18 has a rectangular shape with rounded corners.

[0098] Each channel 5 in which an obstacle 18 is placed is delimited by side walls 20 whose shape is chosen so as to participate in the separation of the flows and in the recombining of the flows 11 in the mixing zone 10 downstream of each obstacle 18 .

[0099] The side wall 20 of the channel has a series of 90° bends 21 so as to force the independent flow 11 to flow around the obstacle 18 along 90° bends.

[0100] The flow network 4 comprises a plurality of channels 5 arranged side by side, which are symmetrical by being translated relative to each other, each channel 5 housing a plurality of obstacles 18 in order to achieve separation and recombination of the fluid flows, as shown in FIG. 2 .

[0101] Two adjacent channels 5 share a common side wall 20 .

[0102] The network 4 for the circulation of fluids comprises a fluid flow section 23 downstream of each mixing zone 10 , so that the fluid flowing in this fluid flow section 23 has a relatively uniform temperature due to the mixing in the mixing zone.

[0103] The downstream section 23 of the flow has a cross-section for the passage of the fluid which is larger, for example twice larger, than each cross-section of the individual fluid flows 11 .

[0104] In the example described, the width of the obstacle 18 is greater than the width of the downstream section 23 .

[0105] In the variant shown in Figure 4, each channel 30 has an elbow 31 which is no longer at a right angle but has an angle A less than 90°, for example 70°. Identical obstacles 32 are rhombus-shaped and are spaced apart from one another at a constant pitch P. In this example, the independent flows are recombined at an angle of incidence A less than 90°, so as to limit the pressure drop losses.

[0106] It should be noted that Figures 2 to 6 show a series of closely adjacent fluid separation zones and fluid mixing zones. These figures are schematic, and the separation-mixing zone pairs (also referred to as patterns) can be spaced farther apart from each other. In fact, this re-combination advantageously provides a better mixing effect than conventionally achieved in the prior art. This means that this type of re-combination enables uniform mixing downstream and allows the patterns to be spaced apart.

[0107] In another embodiment of the invention shown in Figure 5, a network 50 for fluid circulation comprises a series of separation zones 51, each of which extends towards two different channels 52, in which the flow is divided into two strands. These channels 52 reunite in a mixing zone 54, in which the independent flows reunite.

[0108] Each separation zone 51, separation channel 52 and mixing zone 54 forms a basic pattern 55. The network 50 for fluid circulation comprises a series of such patterns 55 regularly spaced apart by predetermined steps.

[0109] Each pattern 55 has a maximum dimension pmax, in this case measured in the longitudinal direction, which is at least 20, 15, 10 or 5 times smaller than the maximum dimension Dmax of the network 50 for fluid circulation, also measured in the longitudinal direction. In the example described, there are ten patterns 55.

[0110] In the example described, certain individual flows of the fluid channels 52 leading to the mixing zone 54 are arranged on two different planes P1 and P2.

[0111] The network 50 for the circulation of the fluid creates a flow bend 56 from one plane P1 or P2 to the other.

[0112] Thus, the heat transfer fluid circulates from one plane P1 or P2 to the other. When they merge or recombine, the individual flows meet at an angle enabling mixing, in this case substantially equal to 90°. The circulation network 50 uses the flow directions in three-dimensional space.

[0113] In this embodiment of the invention, the network for the circulation of fluids comprises tubes 57 in which the heat transfer fluid circulates, these tubes being designed to define mixing zones 54 of the independent flows.

[0114] FIG. 6 shows yet another embodiment according to the present invention.

[0115] In this example, the means for thermal regulation comprise two plates 61 and 62 having raised areas 63, in this case stamped areas, so as to form a network for the circulation of fluids together with zones for mixing fluids. Each protrusion 63 has a pattern with longitudinal branches 64 to which two transverse branches 65 are connected. The channels are repeated in parallel rows 67 on each of the plates 61 and 62. The pattern of one of the plates 61, 62 is mirror-symmetrical to that of the other plate 61, 62 and is offset by a predetermined step from one plate to the other.

[0116] Thus, a fluid network is formed between these plates 61 and 62 , which is indicated by reference arrows 69 .

[0117] FIG. 6 shows firstly the two plates 61 and 62 which have not yet been assembled and secondly the fluid network 69 to be obtained.

[0118] The network for fluid circulation obtained in this example is substantially similar to the network 50 described in the example of FIG. 5 , which uses flows in three-dimensional space.

Claims

1. A heat regulating device (1), in particular a device for cooling, for a component (101) capable of releasing heat during operation, in particular for an electrochemical energy storage module, comprising a circulation network (4; 50) for a heat transfer fluid, the network comprising at least one fluid mixing zone (10; 54), into which at least two independent fluid flows (11) are directed according to respective angles selected so as to produce a mixture of a fluid boundary layer (12) and a fluid internal layer (14) in the mixing zone.

2. The device according to claim 1, wherein: The angle of incidence between the two fluid flows (11) leading to the mixing zone (10) is between 45° and 90°.

3. A device as claimed in any one of the preceding claims, wherein: The circulation network (4; 50) comprises: - a fluid separation zone (16; 51) designed to separate a fluid flow into two independent flows; - said fluid mixing zone (10; 54) to which said independent fluid flows are directed to achieve said mixing.

4. The device as claimed in claim 3, wherein: The separation zone (16) comprises an obstacle (18) placed in a channel of the flow network, the obstacle being designed to separate the fluid flow into two flows.

5. The device according to claim 4, wherein: The obstacle (18) extends along the entire height of the passage (5), the obstacle being in particular polygonal, in particular substantially rectangular.

6. The device as claimed in any one of claims 4 and 5, wherein: The channel (5) in which the obstacle (18) is placed has side walls (20) whose shape is selected to participate in the separation of the flows and in the joining of the independent flows in the mixing zone downstream of the obstacle (18).

7. The device according to claim 6, wherein: The side walls (20) of the channel each have a bend (21), in particular a bend of 45° to 90°, so as to force the independent flow to flow around the obstacle along a bend, in particular a bend of 45° to 90°.

8. A device as claimed in any one of the preceding claims, wherein: The network for fluid circulation comprises a fluid flow section (23) downstream of the mixing zone, so that the fluid flowing in the fluid flow section has a relatively uniform temperature due to the mixing in the mixing zone, and the fluid flow section particularly has a cross-section for fluid passage, which is larger than the cross-section of each of the independent fluid flows, for example 2 times larger.

9. A device as claimed in any one of the preceding claims, wherein: The flow network comprises a plurality of basic patterns (55), each basic pattern being formed by a fluid separation zone and an associated mixing zone.

10. A device as claimed in any preceding claim, wherein: The independent fluid flows leading to the mixing zone are arranged on different planes (P1 , P2).

11. A device as claimed in any one of the preceding claims, wherein: The circulation network (5) is formed between the lower plate (3) and the upper plate (2).

12. The device of claim 11, wherein: At least one of the plates (2; 3) comprises a raised area, in particular a punched area, in order to form the one or more channels of the network and / or the one or more fluid mixing zones.

13. The device according to any one of claims 1 to 10, wherein: Said network (50) for the circulation of fluids comprises one or more tubes (57) inside which said heat transfer fluid circulates, said tube or tubes being designed to define said one or more zones for mixing said independent flows.

14. An assembly (100) comprising a component capable of releasing heat during operation and a device (1) for thermal regulation as claimed in any one of the preceding claims, the component being cooled by contact with the device.

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