Heat transfer device and battery module using the same

Abstract

To provide a heat transport device that can improve an ability to transport heat.SOLUTION: A case 21 comprises a heat absorbing part 21a formed in a flat plate shape, and a heat dissipating part 21b provided with a heat dissipating surface 24a extending in a direction orthogonal to a direction in which the heat absorbing part 21a extends, on the side of an end part of the heat absorbing part 21a. An evaporating space 21a1 extending in a planar shape, and for evaporating liquid working fluid by absorbed heat is formed in the heat absorbing part 21a. A condensing space 21b1 extending in a direction orthogonal to a direction in which the evaporating space 21a1 extends, along the heat dissipating surface 24a, and for condensing the liquid working fluid by dissipating heat is formed in the heat dissipating part 21b. The heat dissipating surface 24a is provided in a heat transfer member 24 for transferring heat absorbed by the working fluid in the heat dissipating part 21b to the outside of the case 21. The heat transfer member 24 comprises a protruding part 24b protruding toward the side of the evaporating space 21a1, in the condensing space 21b1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a heat transport device that transports heat by utilizing the phase change of a working fluid, and a battery module using the same.

Background Art

[0002] As a conventional heat transport device, there is known a vapor chamber having an evaporation space that absorbs heat released from a heating element and evaporates a working fluid, and a condensation space that is provided on an end side in the extending direction of the evaporation space and releases the heat absorbed by the working fluid in the evaporation space to condense the working fluid (see, for example, Patent Document 1).

[0003] The conventional heat transport device enlarges the heat dissipation surface that releases heat and increases the heat dissipation amount by expanding the cross-sectional area in the flow direction of the working fluid in the evaporation space in the condensation space.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional heat transport device, a step is formed between the evaporation space and the condensation space, and the working fluid liquefied in the condensation space tends to accumulate in the condensation space, making it difficult to circulate the working fluid toward the evaporation space, and there is a risk that the ability to transport heat may decrease.

[0006] An object of the present invention is to provide a heat transport device capable of improving the heat transport ability and a battery module using the same.

Means for Solving the Problems

[0007] The heat transport device according to the present invention is a heat transport device including a housing in which a working fluid is enclosed. The housing is formed in a flat plate shape and has a heat absorption part that absorbs heat released from a heating element, and a heat dissipation surface that extends in a direction orthogonal to the extending direction of the heat absorption part is provided on an end side of the heat absorption part. The heat absorption part has a heat dissipation part that releases the heat absorbed in the heat absorption part from the heat dissipation surface. In the heat absorption part, an evaporation space that extends in a planar shape and evaporates the liquid working fluid by the absorbed heat is formed. In the heat dissipation part, a condensation space that extends along the heat dissipation surface in a direction orthogonal to the extending direction of the evaporation space and condenses the gaseous working fluid by releasing heat is formed. The heat dissipation surface is provided on a heat transfer member that transfers the heat absorbed by the working fluid in the heat dissipation part to the outside of the housing. The heat transfer member has an overhanging part that protrudes toward the evaporation space in the condensation space.

[0008] Further, in the heat transport device according to the present invention, the overhanging part is a plurality of fins arranged at intervals in the extending direction of the heat absorption part in the condensation space.

[0009] Further, the heat transport device according to the present invention includes a plurality of wick parts that circulate the working fluid condensed in the condensation space to the evaporation space side. The plurality of wick parts each extend toward the evaporation space along each of the plurality of fins in the condensation space.

[0010] Further, in the heat transport device according to the present invention, the size of the condensation space in a direction orthogonal to the extending direction of the evaporation space gradually decreases toward the evaporation space.

[0011] Further, the battery module according to the present invention includes the heat transport device, a battery cell laminated on the heat absorption part of the heat transport device, and a cooling jacket to which the heat released from the heat dissipation surface provided on the heat dissipation part of the heat transport device is transmitted.

Advantages of the Invention

[0012] According to the present invention, in the condensation space of the heat dissipation part, it is possible to increase the area where the working fluid exchanges heat, promote the condensation of the gaseous working fluid, and at the same time, cause the liquid working fluid in the condensation space to flow into the evaporation space with a short moving distance, enabling the liquid working fluid to efficiently flow from the condensation space into the evaporation space. Therefore, it is possible to improve the heat transport capacity.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view of a battery module, FIG. 2 is a cross-sectional view of a main part of a heat transport device, FIG. 3 is an exploded perspective view of a main part of a heat transport device, and FIG. 4 is a plan view of a heat transfer member. In this embodiment, the X direction in FIG. 1 is the right direction, the Y direction is the front direction, and the Z direction is the upper direction for description.

[0015] The battery module 1 to which the heat transport device of the present invention is applied is, for example, applied to vehicles such as electric vehicles and hybrid vehicles, and is for supplying power to an electric motor as a power source.

[0016] As shown in Fig. 1, the battery module 1 includes a plurality of battery cells 10 as heat generating bodies arranged side by side in the vertical direction (Z direction in Fig. 1), a plurality of heat transport devices 20 laminated on each battery cell 10 for transferring the heat released from the battery cell 10, and a cooling jacket 30 for absorbing the heat released from the heat transport device 20.

[0017] Each of the plurality of battery cells 10 is, for example, a lithium ion secondary battery. Each of the plurality of battery cells 10 is formed in a rectangular plate shape by covering materials such as electrodes and electrolytes with a laminate film. The electrode 11 protrudes from the right end of the battery cell 10. The battery cell 10 is formed to have a thickness of about 10 mm, for example.

[0018] Each of the plurality of heat transport devices 20 is a so-called vapor chamber that absorbs the heat released from the battery cell 10, transports it in the width direction, and releases it to the cooling jacket 30.

[0019] As shown in Fig. 2, the heat transport device 20 includes a housing 21 in which a working fluid is enclosed. Here, the working fluid enclosed in the housing 21 is, for example, water, fluorocarbons, cyclopentane, ethylene glycol, or a mixture thereof.

[0020] The housing 21 is formed in a rectangular plate shape by a member with high thermal conductivity such as an aluminum alloy, stainless steel, or copper alloy. The housing 21 is formed to have a size in the front-rear direction substantially the same as that of the battery cell 10 in the front-rear direction, and a size in the width direction slightly larger than that of the battery cell 10 in the width direction.

[0021] As shown in Figs. 2 and 3, the housing 21 has a pair of plate-like members 22 facing each other, a pair of wick sheets 23 provided on the respective facing surfaces of the pair of plate-like members 22 for allowing the liquid working fluid to flow, and a heat transfer member 24 disposed on the left end side of the pair of plate-like members 22 for transferring the heat of the working fluid to the cooling jacket 30.

[0022] The plate-shaped member 22 is, for example, a plate-shaped member with a thickness of 0.3 mm.

[0023] The wick sheet 23 is composed of, for example, a sheet-shaped member with a thickness of 0.2 mm formed by knitting metal wires. As shown in FIG. 3, the wick sheet 23 has a plurality of wick portions 23a for allowing the liquid working fluid to flow in the width direction and a plurality of vapor flow portions 23b for allowing the gaseous working fluid to flow in the width direction, which are alternately arranged in the front-rear direction. The wick portion 23a is formed in a strip shape with metal wires knitted therein and uses capillary action to move the liquid working fluid.

[0024] The heat transfer member 24 is a member that extends in the front-rear direction on the left end side of the pair of plate-shaped members 22. As shown in FIG. 2, the heat transfer member 24 has a heat radiating surface 24a that releases heat to the cooling jacket 30 by contacting the outer surface of the cooling jacket 30. The heat radiating surface 24a is formed on the left side surface of the heat transfer member 24 to have a vertical size of, for example, 10 mm and extend in the front-rear direction. Further, as shown in FIGS. 2 to 4, the heat transfer member 24 has an overhanging portion 24b that protrudes rightward from the right side surface. The overhanging portion 24b protrudes rightward from the right side surface of the heat transfer member 24 by, for example, 20 mm and is a plurality of fins 24c arranged at intervals in the front-rear direction. Each of the plurality of fins 24c is formed such that the vertical size gradually decreases from the base end side to the tip end side.

[0025] As shown in Fig. 3, the housing 21 is formed by arranging a pair of wick sheets 23 between a pair of plate-like members 22 and closing the outer peripheral portion in a state where the heat transfer member 24 is sandwiched vertically by the pair of plate-like members 22 and the pair of wick sheets 23 on the left end side. At this time, the heat transfer member 24 supports the pair of plate-like members 22 and the pair of wick sheets 23 by a plurality of fins 24c. Further, the wick portions 23a of the wick sheets 23 are located on the upper and lower surfaces of the plurality of fins 24c of the heat transfer member 24, and the vapor flow portions 23b of the wick sheets 23 are located between the fins 24c adjacent to each other in the front-rear direction.

[0026] As shown in Fig. 2, the housing 21 is formed in a flat plate shape and has a heat absorption portion 21a that absorbs heat released from the battery cell 10, and a heat radiation surface 24a that extends in the vertical direction orthogonal to the horizontal direction in which the heat absorption portion 21a extends is provided on the end side of the heat absorption portion 21a, and a heat radiation portion 21b that releases the heat absorbed in the heat absorption portion 21a from the heat radiation surface 24a. The heat absorption portion 21a of the housing 21 is formed, for example, to have a size in the thickness direction of 1 mm.

[0027] An evaporation space 21a1 that extends in a planar shape and evaporates the liquid working fluid by the absorbed heat is formed in the heat absorption portion 21a.

[0028] A condensation space 21b1 that extends in the vertical direction orthogonal to the horizontal direction in which the evaporation space 21a1 extends along the heat radiation surface 24a and releases heat to condense the gaseous working fluid is formed in the heat radiation portion 21b.

[0029] The condensation space 21b1 is formed such that the size in the vertical direction orthogonal to the horizontal direction in which the evaporation space 21a1 extends gradually decreases toward the evaporation space 21a1 and is connected to the evaporation space 21a1. In the condensation space 21b1 of the present embodiment, the plate-like members 22 located on both the upper and lower sides of the evaporation space 21a1 extend obliquely linearly and are connected to the evaporation space 21a1.

[0030] The cooling jacket 30 is made of a hollow member made of a metal such as an aluminum alloy. Inside the cooling jacket 30, cooling water pumped by equipment such as a pump (not shown) circulates. The cooling water circulating inside the cooling jacket 30 is, for example, the cooling water after being radiated by a radiator. The cooling water is water or a coolant such as ethylene glycol.

[0031] In the battery module 1 configured as described above, the heat released from the battery cell 10 is transmitted to the heat absorption part 21a of the housing 21 of the heat transport device 20 adjacent above and below. The heat transmitted to the heat absorption part 21a of the heat transport device 20 evaporates the liquid working fluid in the evaporation space 21a1 of the heat absorption part 21a. The working fluid evaporated in the evaporation space 21a1 of the housing 21 flows through the vapor flow part 23b of the wick sheet 23 of the housing 21 shown in FIG. 3 toward the condensation space 21b1 side of the heat radiation part 21b. The gaseous working fluid flowing into the condensation space 21b1 exchanges heat with the cooling water flowing through the inside of the cooling jacket 30 via the heat transfer member 24, and thus radiates heat and condenses. The working fluid condensed in the condensation space 21b1 flows through the wick part 23a of the wick sheet 23 toward the evaporation space 21a1 side. The cooling water that has absorbed heat inside the cooling jacket 30, after flowing out of the cooling jacket 30, releases heat into the air by flowing through, for example, a radiator.

[0032] The working fluid that has absorbed heat and evaporated in the evaporation space 21a1 of the heat absorption part 21a exchanges heat with the cooling water flowing through the cooling jacket 30 via the heat transfer member 24 in the condensation space 21b1 of the heat radiation part 21b whose vertical size is larger than the vertical size of the evaporation space 21a1. Therefore, the heat exchange area between the working fluid and the cooling water increases, and the condensation of the gaseous working fluid is promoted. Further, since the heat transfer member 24 has an overhanging part 24b that projects toward the evaporation space 21a1 side in the condensation space 21b1, the heat exchange area between the working fluid and the cooling water becomes larger, and the condensation of the gaseous working fluid is further promoted. Furthermore, since the overhanging part 24b of the heat transfer member 24 is a plurality of fins 24c arranged at intervals in the direction in which the heat absorption part 21a extends in the condensation space 21b1, the heat exchange area between the working fluid and the cooling water becomes even larger, and the condensation of the gaseous working fluid is further promoted.

[0033] Also, the working fluid that has condensed in the condensation space 21b1 flows through the wick part 23a of the wick sheet 23 located on the upper side and the lower side of the condensation space 21b1 whose vertical size gradually becomes smaller and flows into the evaporation space 21a1 of the heat absorption part 21a. As a result, the liquid working fluid in the condensation space 21b1 flows into the evaporation space 21a1 over a short moving distance, so that the liquid working fluid in the condensation space 21b1 smoothly flows into the evaporation space 21a1.

[0034] Thus, according to the heat transport device 20 of this embodiment, the heat transport device 20 includes a housing 21 in which a working fluid is enclosed. The housing 21 is formed in a flat plate shape and has a heat absorption portion 21a that absorbs heat released from the battery cell 10 as a heating element, and a heat radiation surface 24a that extends in a direction orthogonal to the extending direction of the heat absorption portion 21a is provided on the end side of the heat absorption portion 21a. The heat radiation portion 21b that releases the heat absorbed in the heat absorption portion 21a from the heat radiation surface 24a. In the heat absorption portion 21a, an evaporation space 21a1 that extends in a planar shape and evaporates the liquid working fluid by the absorbed heat is formed. In the heat radiation portion 21b, a condensation space 21b1 that extends in a direction orthogonal to the extending direction of the evaporation space 21a1 along the heat radiation surface 24a and releases heat to condense the gaseous working fluid is formed. The heat radiation surface 24a is provided on a heat transfer member 24 that transfers the heat absorbed by the working fluid in the heat radiation portion 21b to the outside of the housing 21. The heat transfer member 24 has an overhanging portion 24b that protrudes toward the evaporation space 21a1 side in the condensation space 21b1.

[0035] Thereby, in the condensation space 21b1 of the heat radiation portion 21b, it is possible to increase the heat exchange area between the working fluid and the cooling water and promote the condensation of the gaseous working fluid. Therefore, it is possible to improve the ability to transport heat.

[0036] Also, it is preferable that the overhanging portion 24b is a plurality of fins 24c arranged at intervals in the extending direction of the heat absorption portion 21a in the condensation space 21b1.

[0037] Thereby, in the condensation space 21b1, it is possible to further increase the heat exchange area between the working fluid and the cooling water, and thus it is possible to further promote the condensation of the gaseous working fluid.

[0038] Also, a plurality of wick portions 23a for circulating the working fluid condensed in the condensation space 21b1 to the evaporation space 21a1 side are provided. Each of the plurality of wick portions 23a preferably extends toward the evaporation space 21a1 side along each of the plurality of fins 24c in the condensation space 21b1.

[0039] As a result, in the condensation space 21b1, the vapor flow portion 23b is disposed between the fins 24c arranged at intervals, and the gaseous working fluid can reach a position close to the heat dissipation surface 24a. Therefore, the gaseous working fluid can be condensed more efficiently.

[0040] Further, it is preferable that the condensation space 21b1 has a size in a direction orthogonal to the extending direction of the evaporation space 21a1 that gradually decreases toward the evaporation space 21a1.

[0041] As a result, the liquid working fluid in the condensation space 21b1 can flow into the evaporation space 21a1 with a short moving distance, and the liquid working fluid can be efficiently made to flow from the condensation space 21b1 into the evaporation space 21a1. Therefore, it is possible to further improve the heat transport capacity.

[0042] Further, according to the battery module 1 of the present embodiment, it is preferable to include a heat transport device 20, a battery cell 10 laminated on the heat absorption portion 21a of the heat transport device 20, and a cooling jacket 30 to which the heat released from the heat dissipation surface 24a of the heat dissipation portion 21b of the heat transport device 20 is transmitted.

[0043] As a result, the heat released from the battery cell 10 can be reliably released by the heat transport device 20 to the cooling water flowing through the cooling jacket 30. Therefore, it is possible to maintain the performance of the battery cell 10.

[0044] FIG. 5 shows another embodiment of the present invention. In addition, the same reference numerals are given to the same components as those in the above embodiment.

[0045] The condensation space 21b1 of the housing 21 shown in FIGS. 5(a) and 5(b) is formed such that, similar to the above embodiment, the size in the vertical direction orthogonal to the horizontal direction in which the evaporation space 21a1 extends gradually decreases toward the evaporation space 21a1.

[0046] As shown in Fig. 5(a), the condensation space 21b1 of the housing 21 is connected to the evaporation space 21a1 by the plate-like members 22 located on the upper and lower sides of the evaporation space 21a1 extending in a curved shape.

[0047] Also, as shown in Fig. 5(b), in the condensation space 21b1 of the housing 21, one plate-like member 22 of the evaporation space 21a1 extends linearly toward the evaporation space 21a1 side, and the other plate-like member 22 extends linearly obliquely toward the evaporation space 21a1 side and is connected to the evaporation space 21a1.

[0048] Thus, according to the heat transport device 20 of the present embodiment, similar to the above embodiment, in the condensation space 21b1 of the heat dissipation part 21b, it is possible to increase the heat exchange area between the working fluid and the cooling water and promote the condensation of the gaseous working fluid, so that it is possible to improve the heat transport capacity.

[0049] Also, it is preferable that the size of the condensation space 21b1 in the direction orthogonal to the extending direction of the evaporation space 21a1 gradually decreases toward the evaporation space 21a1.

[0050] Thereby, the liquid working fluid in the condensation space 21b1 can be made to flow into the evaporation space 21a1 with a short moving distance, and it is possible to efficiently make the liquid working fluid flow from the condensation space 21b1 into the evaporation space 21a1, so that it is possible to further improve the heat transport capacity.

[0051] In the above embodiment, the heat dissipation part 21b is provided only at one end in the width direction of the heat absorption part 21a of the housing 21 of the heat transport device 20, and heat is released from the heat dissipation surface 24a of the heat dissipation part 21b to the cooling water flowing through the cooling jacket 30, but it is not limited thereto. For example, a heat absorption part may be arranged at the center in the width direction of the housing 21 of the heat transport device 20, heat dissipation parts may be arranged on both ends in the width direction of the heat absorption part, and heat may be released from the heat dissipation surfaces of the heat dissipation parts on both sides in the width direction.

[0052] In addition, in the above-described embodiment, a pair of wick sheets 23 are disposed between a pair of plate-like members 22, but the present invention is not limited thereto. As long as the working fluid of the liquid is caused to flow from the condensation space 21b1 to the evaporation space 21a1 by utilizing capillary action, for example, a single wick sheet may be disposed between the pair of plate-like members. Further, for example, without disposing a wick sheet between the pair of plate-like members, a wick structure may be formed by sintering metal powder or forming grooves on the surfaces of the pair of plate-like members on the condensation space and evaporation space sides.

[0053] In addition, in the above-described embodiment, by forming a plurality of fins 24c as overhanging portions 24b on the heat transfer member 24, the heat exchange area between the gaseous working fluid in the condensation space 21b1 and the cooling water flowing through the cooling jacket 30 is increased. However, the present invention is not limited thereto. As long as it protrudes from the heat transfer member toward the evaporation space in the condensation space, for example, a plurality of protrusions each formed in a conical shape may be used as the overhanging portion, or a plurality of protrusions formed by subjecting the surface of the heat transfer member 24 located in the condensation space 21b1 to roughening treatment may be used as the overhanging portion.

Explanation of Reference Numerals

[0054] 1 Battery module 10 Battery cell 20 Heat transport device 21 Housing 21a Heat absorption part 21a1 Evaporation space 21b Heat radiation part 21b1 Condensation space 23a Wick part 24 Heat transfer member 24a Heat radiation surface 24b Overhanging portion 24c Fin

Claims

1. A heat transport device comprising a housing enclosing a working fluid therein, wherein the housing is formed in a flat plate shape and has a heat absorption portion that absorbs heat released from a heating element, and a heat dissipation portion that is provided on an end side of the heat absorption portion and extends in a direction orthogonal to the extending direction of the heat absorption portion, and releases the heat absorbed in the heat absorption portion from the heat dissipation surface, an evaporation space that extends in a planar shape and evaporates the liquid working fluid by the absorbed heat is formed in the heat absorption portion, a condensation space that extends along the heat dissipation surface in a direction orthogonal to the extending direction of the evaporation space and releases heat to condense the gaseous working fluid is formed in the heat dissipation portion, the heat dissipation surface is provided on a heat transfer member that transfers the heat absorbed by the working fluid in the heat dissipation portion to the outside of the housing, the heat transfer member has an overhanging portion that projects toward the evaporation space in the condensation space, the overhanging portion is a plurality of fins spaced apart in the extending direction of the heat absorption portion in the condensation space, a plurality of wick portions for circulating the working fluid condensed in the condensation space to the evaporation space side are provided, each of the plurality of wick portions extends toward the evaporation space along each of the plurality of fins in the condensation space, a heat transport device.

2. A heat transport device comprising a housing enclosing a working fluid therein, wherein the housing is formed in a flat plate shape and has a heat absorption portion that absorbs heat released from a heating element, and a heat dissipation portion that is provided on an end side of the heat absorption portion and extends in a direction orthogonal to the extending direction of the heat absorption portion, and releases the heat absorbed in the heat absorption portion from the heat dissipation surface, an evaporation space that extends in a planar shape and evaporates the liquid working fluid by the absorbed heat is formed in the heat absorption portion, a condensation space that extends along the heat dissipation surface in a direction orthogonal to the extending direction of the evaporation space and releases heat to condense the gaseous working fluid is formed in the heat dissipation portion, the heat dissipation surface is provided on a heat transfer member that transfers the heat absorbed by the working fluid in the heat dissipation portion to the outside of the housing, the heat transfer member has an overhanging portion that projects toward the evaporation space in the condensation space, the size of the condensation space in a direction orthogonal to the extending direction of the evaporation space gradually decreases toward the evaporation space, a heat transport device.

3. The heat transport device according to claim 1 or 2, and A battery cell laminated on the heat absorption part of the heat transport device, A cooling jacket through which heat radiated from the heat radiation surface provided on the heat radiation part of the heat transport device is transmitted, and A battery module.

Images