Battery cooling device

Abstract

DEPCT67 This battery cooler cools the battery using a molded heat sink. It includes flow grooves through which the refrigerant flows, as well as the flow grooves of the unit itself. One end is where the coolant flows in before cooling the battery cells, and the other end... One way in which the refrigerant, after cooling the battery cells, is released is through the flow channel of the unit. A U-shaped element folded back so that its width is equal to or less than the width of the battery cell;

Description

Battery Cooling Device

[0001] The present disclosure relates to a battery cooling device that cools a battery mounted on a vehicle.

[0002] Conventionally, a vehicle battery cooling device has a heat sink (cooler) provided adjacent to the battery (see, for example, Patent Document 1). A flow path through which a refrigerant flows is formed within the heat sink, thereby enabling the refrigerant to reduce the heat of the battery.

[0003] Japanese Patent Application Laid-Open No. 2018-127087

[0004] However, in a conventional battery cooling device that cools a battery by circulating a refrigerant through a flow path, there is a problem in that heat is distributed unevenly.

[0005] This problem will be briefly explained using Figures 1 to 3. Figures 1 and 2 are plan views showing an example in which a heat sink 20 is disposed adjacent to the underside of a battery pack 10. As shown in Figure 3, a plurality of battery cells 11 are provided within the battery pack 10. The shade of the hatched pattern in Figures 1 to 3 represents temperature, with a darker pattern representing a higher temperature.

[0006] 1 shows a case where a flow path (not shown) through which a coolant flows in one direction is formed in the heat sink 20. The coolant flows into the flow path from a coolant inlet 20a and is discharged from a coolant outlet 20b. In practice, the flow path may be a single path or multiple paths may be formed in parallel.

[0007] When a flow path in which the refrigerant flows in one direction is formed as shown in FIG. 1, the temperature of the refrigerant becomes higher downstream, i.e., closer to the refrigerant outlet 20b. As a result, as shown by the shading in FIG. 1, the temperature of the battery pack 10 becomes higher toward the right side of the figure.

[0008] 2 shows a case where a U-shaped flow path (not shown) is formed inside the heat sink 20. Specifically, the flow path extends rightward from the refrigerant inlet 20a, turns back at the right end, and then extends leftward toward the refrigerant outlet 20b.

[0009] When a U-shaped flow path is formed as in Figure 2, the temperature of the refrigerant becomes higher downstream, i.e., closer to the refrigerant outlet 20b, and as a result, the temperature of the battery pack 10 becomes higher toward the upper side in the figure, as indicated by the shading in Figure 2. Note that even if the flow path is not U-shaped but is meander-shaped with multiple folds inside the heat sink 20, the temperature of the battery pack 10 similarly becomes higher toward the upper side in the figure.

[0010] Fig. 3 is a perspective view showing the state of the battery cells 11 in the battery pack 10. The shading in Fig. 3 corresponds to the case where a flow path in which the refrigerant flows in one direction is formed as in Fig. 1. It can be seen that the temperature of the battery cells 11 on the downstream side of the flow path is higher.

[0011] As described above, the conventional battery cooling device causes temperature imbalances among the multiple battery cells 11 provided in the battery pack 10. Specifically, the temperature of the battery cells 11 located downstream of the flow path is higher than the temperature of the battery cells 11 located upstream of the flow path.

[0012] Here, the higher the temperature of the battery cells 11, the faster they deteriorate. This leads to a situation where the battery cells 11 located downstream of the flow path deteriorate faster than the battery cells 11 located upstream of the flow path. Such uneven deterioration of the battery cells 11 within the battery pack 10 leads to a shortened lifespan of the battery as a whole, which is undesirable.

[0013] The present disclosure has been made in consideration of the above points, and provides a battery cooling device that can reduce temperature bias among battery cells.

[0014] One aspect of the battery cooling device of the present disclosure is a vehicle battery cooling device that cools a battery using a heat sink formed with a flow path through which a refrigerant flows, the flow path having a unit flow path into which refrigerant flows before cooling the battery cells from one end and from which refrigerant flows after cooling the battery cells from the other end, and the unit flow path has a U-shape that is folded back at a width equal to or less than the cell width of the battery cells.

[0015] According to the present disclosure, it is possible to reduce temperature bias in the battery.

[0016] 7A is a schematic perspective view showing the configuration of a refrigerant introduction system, and FIG. 7B is a schematic perspective view showing the configuration of a refrigerant discharge system. FIG. 9A is a cross-sectional view taken along line A-A in FIG. 7A, and FIG. 9B is a cross-sectional view taken along line B-B in FIG. 7B.

[0017] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0018] 4 is a schematic perspective view showing the main configuration of the battery cooling device according to the embodiment. Since the main feature of the battery cooling device of the present embodiment is the shape and arrangement of the flow paths, FIG. 4 shows the positional relationship between the flow paths 101 and the battery cells 11.

[0019] First, a basic configuration will be briefly described. The battery and battery cooling device of this embodiment are mounted on a vehicle. The battery has a battery pack (not shown) and a plurality of battery cells 11 arranged therein. A flow path 101 of the battery cooling device is arranged adjacent to the battery. In this embodiment, the flow path 101 is arranged adjacent to the underside of the battery.

[0020] 5, the flow path 101 is formed in the heat sink 100, and the heat sink 100 is disposed adjacent to the battery. The flow path 101 of the heat sink 100 is formed by extruding an aluminum plate, for example.

[0021] In the present embodiment, a plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ... are formed in the heat sink 100. Each of the unit flow paths 101-1, 101-2, 101-3, 101-4, ... is formed in a U-shape folded back at a width equal to or less than the cell width of the battery cell 11. In practice, each of the unit flow paths 101-1, 101-2, 101-3, 101-4, ... has an outgoing path 101a, a returning path 101b, and a folded path 101c.

[0022] Each unit flow path 101-1, 101-2, 101-3, 101-4, ... is formed into a U-shape folded back at a width equal to or less than the cell width of the battery cell 11, so that one or more unit flow paths 101-1, 101-2, 101-3, 101-4, ... pass through each battery cell 11.

[0023] 4 shows an example in which the folded width of the unit flow channels 101-1, 101-2, 101-3, 101-4, ... is set to approximately half the cell width. In this case, it becomes possible for one battery cell 11 to pass through two unit flow channels 101-1, 101-2, 101-3, 101-4, ....

[0024] 6 shows an example in which the folded width of the unit flow channels 101-1, 101-2, 101-3, 101-4, ... is set to be equal to the cell width. In this case, it is possible to pass one unit flow channel 101-1, 101-2, 101-3, 101-4, ... through one battery cell 11.

[0025] As can be seen from Figures 4 and 6, the battery is configured by arranging multiple battery cells 11 in the vertical and horizontal directions within a battery pack, and the unit channels 101-1, 101-2, 101-3, 101-4, ... extend across the multiple battery cells 11 in the vertical direction and are formed in multiple units across the horizontal direction. Furthermore, one or more unit channels 101-1, 101-2, 101-3, 101-4, ... are formed per battery cell in the horizontal direction. Specifically, in the example of Figure 4, two unit channels 101-1, 101-2, 101-3, 101-4, ... are formed per battery cell in the horizontal direction, and in the example of Figure 6, one unit channel 101-1, 101-2, 101-3, 101-4, ... is formed per battery cell in the horizontal direction.

[0026] A refrigerant before cooling the battery cells 11 flows into each of the unit channels 101-1, 101-2, 101-3, 101-4, ... from one end, and a refrigerant after cooling the battery cells 11 is discharged from the other end. As the refrigerant, for example, pure water or a fluorine-based inert liquid is used.

[0027] Next, a description will be given of the configuration of the flow paths for introducing and discharging the refrigerant into and from each of the unit flow paths 101-1, 101-2, 101-3, 101-4, .... Fig. 7A is a schematic perspective view showing the configuration of a refrigerant introduction system, and Fig. 7B is a schematic perspective view showing the configuration of a refrigerant discharge system.

[0028] 7A and 7B, an equalizing tank 102a is connected to the end of the outgoing path 101a, and an equalizing tank 102b is connected to the end of the return path 101b. In other words, a first equalizing tank 102a is connected to one end of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, and a second equalizing tank 102b is connected to the other end of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, and

[0029] The pressure-equalizing tank 102a has an internal space that connects the refrigerant inlet 103a to the multiple outgoing paths 101a. Because the multiple outgoing paths 101a are connected to the refrigerant inlet 103a through the same internal space, when the refrigerant is introduced into the internal space of the pressure-equalizing tank 102a from the refrigerant inlet 103a, the refrigerant flows into the multiple outgoing paths 101a at the same pressure.

[0030] Similarly, the pressure equalizing tank 102b has an internal space that connects the refrigerant outlet 103b to the plurality of return paths 101b. Because the plurality of return paths 101b are connected to the refrigerant outlet 103b through the same internal space, the refrigerants in the plurality of outward paths 101a are discharged with the same resistance.

[0031] In this way, by connecting the pressure equalizing tank 102a to one end of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ... and connecting the pressure equalizing tank 102b to the other end of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ..., it is possible to make the flow speed of the refrigerant the same in each of the unit flow paths 101-1, 101-2, 101-3, 101-4, .... As a result, the cooling performance is the same among the unit flow paths 101-1, 101-2, 101-3, 101-4, ....

[0032] 8 is a schematic perspective view showing the arrangement of the pressure equalizing tanks 102 a and 102 b. As can be seen from the drawing, in this embodiment, the pressure equalizing tank 102 a is arranged on the side surface of the heat sink 100, and the pressure equalizing tank 102 b is arranged on the top surface of the heat sink 100.

[0033] 9A is a cross-sectional view taken along the line AA in FIG. 7A, ie, a cross-sectional view taken along a plane including the outgoing path 101a, and FIG. 9B is a cross-sectional view taken along the line BB in FIG. 7B, ie, a cross-sectional view taken along a plane including the returning path 101b.

[0034] FIG. 10 is a schematic perspective view showing the pressure equalizing tank 102 a attached to the heat sink 100 .

[0035] In the battery cooling device of this embodiment, a refrigerant is supplied from a refrigerant supply unit (not shown) into the pressure-equalizing tank 102a through the refrigerant inlet 103a. The refrigerant flows at the same flow rate through the unit flow paths 101-1, 101-2, 101-3, 101-4, etc. due to the action of the pressure-equalizing tanks 102a and 102b. The refrigerant, whose temperature has increased by flowing through the unit flow paths 101-1, 101-2, 101-3, 101-4, etc., is discharged through the pressure-equalizing tank 102b and the refrigerant outlet 103b.

[0036] At this time, the battery cells 11 are cooled to approximately the same temperature regardless of their positions in the vertical and horizontal directions. This point will be described with reference to FIG.

[0037] First, a description will be given of the temperatures of the battery cells 11 in the vertical direction. As an extreme example, the temperature of the battery cell 11x1 arranged closest to the refrigerant inlet / outlet will be compared with the temperature of the battery cell 11x2 arranged closest to the turning path 101c.

[0038] The battery cell 11x1 is passed through by the coolant with the lowest temperature in the outgoing path 101a and the coolant with the highest temperature in the return path 101b. Therefore, it can be said that the cooling effect on the battery cell 11x1 is medium.

[0039] On the other hand, the battery cell 11x2 is passed through by the refrigerant with the highest temperature in the outgoing path 101a and the refrigerant with the lowest temperature in the returning path 101b. Therefore, it can be said that the cooling effect on the battery cell 11x2 is medium.

[0040] Therefore, the cooling for the battery cell 11x1 and the cooling for the battery cell 11x2 are performed to the same extent, and no temperature imbalance occurs in the vertical direction.

[0041] Next, a description will be given of the temperatures of the horizontal battery cells 11. As an example, the temperatures of the battery cell 11x1 and the battery cell 11x3 will be compared.

[0042] Since the battery cell 11x1 and the battery cell 11x3 both pass through the same number of outgoing paths 101a and returning paths 101b, the cooling of the battery cell 11x1 and the cooling of the battery cell 11x3 are performed to the same extent. Therefore, there is no temperature imbalance in the lateral direction.

[0043] As described above, according to this embodiment, in a vehicle battery cooling device that cools a battery using a heat sink 100 formed with a flow path through which a refrigerant flows, the flow path has unit flow paths 101-1, 101-2, 101-3, 101-4, ... into which refrigerant flows before cooling the battery cells 11 from one end and from which refrigerant flows after cooling the battery cells 11 from the other end, and the unit flow paths 101-1, 101-2, 101-3, 101-4, ... have a U-shape that is folded back at a width equal to or less than the cell width of the battery cells 11.

[0044] This makes it possible to realize a battery cooling device that can reduce temperature bias among the battery cells 11 and thereby extend the battery life.

[0045] Furthermore, according to this embodiment, the battery is configured by arranging a plurality of battery cells 11 vertically and horizontally within a battery pack, and the unit flow paths 101-1, 101-2, 101-3, 101-4, ... extend across the plurality of battery cells 11 in the vertical direction and are also formed in multiple locations in the horizontal direction.

[0046] This makes it possible to reduce temperature deviations in both the vertical and horizontal directions for the battery cells 11 arranged in the vertical and horizontal directions.

[0047] Furthermore, according to this embodiment, there is provided a plate-shaped heat sink 100 in which a plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ... are formed, a first pressure equalizing tank 102a connected to one ends of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ..., and a second pressure equalizing tank 102b connected to the other ends of the plurality of unit flow paths 101-1, 101-2, 101-3, 101-4, ..., and the unit flow paths 101-1, 101-2, 101-3, 101-4, ... are folded back in a U-shape in the surface direction of the plate-shaped heat sink 100, and the first pressure equalizing tank 102a is arranged on the side of the heat sink 100, and the second pressure equalizing tank 102b is arranged on the upper surface of the heat sink 100.

[0048] This makes it easy to remove air if it gets into the unit passages 101-1, 101-2, 101-3, 101-4, .... In other words, as can be seen from Fig. 9, the refrigerant outlet (Fig. 9B) from the flow path (return path 101b) is higher than the refrigerant inlet (Fig. 9A) to the flow path (outgoing path 101a), and the refrigerant outlet faces upward, so even if air gets into the unit passages 101-1, 101-2, 101-3, 101-4, ..., this air can be easily discharged from the refrigerant outlet.

[0049] The above-described embodiments are merely examples of specific embodiments for carrying out the present disclosure, and the technical scope of the present disclosure should not be interpreted as being limited by these embodiments. In other words, the present disclosure can be embodied in various forms without departing from the gist or main features thereof.

[0050] In the above-described embodiment, each unit flow channel 101-1, 101-2, 101-3, 101-4, ... has been described as having a single U-shape folded back at a width equal to or less than the cell width. However, the present disclosure is not limited to this, and each unit flow channel 101-1, 101-2, 101-3, 101-4, ... may have two or more U-shapes. In other words, each unit flow channel 101-1, 101-2, 101-3, 101-4, ... may be folded back two or more times. However, it is preferable that each unit flow channel 101-1, 101-2, 101-3, 101-4, ... fits within one cell width. Therefore, if the flow channel is folded back twice, the folding width is preferably 1 / 2 of the cell width, and if the flow channel is folded back three times, the folding width is preferably 1 / 3 of the cell width.

[0051] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2021-154308, filed on September 22, 2021, are incorporated herein by reference in their entirety.

[0052] The present disclosure is useful as a cooling device for a battery having a plurality of battery cells.

[0053] 10 Battery pack 11, 11x1, 11x2, 11x3 Battery cells 20, 100 Heat sink 20a, 103a Refrigerant inlet 20b, 103b Refrigerant outlet 101 Flow path 101-1, 101-2, 101-3, 101-4 Unit flow path 101a Outward path 101b Return path 101c Turning path 102a, 102b Pressure equalizing tank

Claims

DEPCT671. Vehicle battery cooling device for cooling the battery by using a heat sink which includes grooves formed in it and through which the refrigerant flows, where the grooves include unit grooves through which the refrigerant before cooling the battery cells is injected from one end of the unit groove and the refrigerant after cooling the battery cells is discharged from the other end of the unit groove, and the unit grooves are U-shaped at 5 and formed by folding to a width equal to or shorter than the cell width of the battery cells.

2. Battery cooling device according to claim 1 where the battery is configured by arranging a number of battery cells in a battery pack in the longitudinal and lateral directions, and unit grooves extend over the number of battery cells in the longitudinal direction, and a number of unit grooves are formed in the lateral direction.

3. Battery cooling device according to claim 2 where at least one of a number of unit grooves is formed for each cell of a number of battery cells in the lateral direction. 4.Any one of the claims 1 through 3 shall be incorporated with a plate-shaped heat sink in which a number of unit grooves are formed, a first pressure balancing tank connected to one end of each of the number of unit grooves, and a second pressure balancing tank connected to the other end of each of the number of unit grooves, where each of the number of unit grooves is folded to form a U-shape in the direction of the surface of the plate-shaped heat sink, the first pressure balancing tank is placed on the side surface of the heat sink, and the second pressure balancing tank is placed on the top surface of the heat sink;

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