JP2016191522A - Cooling mechanism of heating structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling mechanism capable of improving cooling performance while saving the space.SOLUTION: A heat pipe 5 has an evaporation part 5a that is a first portion extending through a region 2a between a plurality of element bodies 2, and a condensation part 5b that is a second portion positioned outside a heating structure 21. The condensation part 5b extends in a direction different from a direction in which the evaporation part 5a extends.SELECTED DRAWING: Figure 1C

Description

  The present invention relates to a cooling mechanism for a heat generating structure, and more particularly, to a cooling mechanism for cooling a heat generating structure including a plurality of heat generating elements.

  An air cooling type cooling mechanism is known as a cooling mechanism for cooling a heat generating structure in which a plurality of heat generating elements are arranged in parallel. The air-cooling type cooling mechanism has flow paths provided between the heat generating elements and cools each heat generating element by flowing air through these flow paths. In this cooling mechanism, in order to increase the air flow rate and improve the cooling capacity, it is necessary to increase the gap of the flow path. However, increasing the gap of the flow path leads to an increase in the size of the cooling mechanism.

  On the other hand, Patent Document 1 discloses a portable electric device that cools a secondary battery by a cooling mechanism including a heat pipe in which a working fluid is sealed. In this portable electric device, a heat pipe is inserted into the secondary battery. The condensing part of the heat pipe is exposed to the outside and is disposed in an exhaust passage through which air flows. A plurality of radiating fins are attached to the exposed portion of the heat pipe. With this configuration, the heat of the secondary battery is released into the air flowing through the exhaust passage through the heat pipe and the heat radiating fins. Therefore, the secondary battery can be cooled using a working fluid having a higher thermal conductivity than air, and the heat transfer area can be increased by means of heat radiation fins, etc. However, the cooling capacity can be improved.

JP 2006-155989 A

  In the cooling mechanism provided with the heat pipe described in Patent Document 1, heat is radiated in the condensing part where the heat pipe is exposed. Therefore, in order to improve the cooling capacity, it is important to lengthen the condensing part. However, if the condensing part is lengthened, the cooling mechanism becomes longer in the direction away from the heat generating structure, so that a space is required around the heat generating structure. However, when the heat generating structure is incorporated in another device, it is difficult to provide a space around it.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a cooling mechanism for a heat generating structure that can improve the cooling capacity while saving space.

The cooling mechanism of the heat generating structure according to the present invention is:
A cooling mechanism for a heating structure including a plurality of heating elements,
A plurality of heat pipes having a first portion extending in a region between the plurality of heating elements and a second portion located outside the heating structure;
The second portion extends along an outer surface of the heat generating structure in a direction different from that of the first portion. The heat generating structure includes a plurality of regions, and each of the plurality of regions includes at least one of the regions. The first portion of the two heat pipes extends;
The second portions of each of the plurality of heat pipes extend in parallel to each other, and each of the first portions of the heat pipe is in an in-plane direction of the region and the extending direction of the first portion. Extending in different positions with respect to the orthogonal direction,
The plurality of heating elements are arranged in one direction, each of the second portions of the plurality of heat pipes extends in the one direction, and a plurality of the heat pipes have tips of the second portions. There are the heat pipe that faces the first direction and the heat pipe that the tip of the second part faces the second direction opposite to the first direction.

  According to the above invention, the second portion of the heat pipe that is located outside the heat generating structure extends in a direction different from the first portion that extends in the region between the plurality of heat generating elements included in the heat generating structure. Therefore, even if the second portion is lengthened, it is possible to prevent the cooling mechanism from extending toward the outside of the heat generating structure.

  Therefore, according to the present invention, it is possible to improve the cooling capacity while saving space.

It is a perspective view which shows typically the apparatus provided with the cooling mechanism of the 1st Embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows the apparatus provided with the cooling mechanism which concerns on the 1st Embodiment of this invention. It is a schematic sectional side view which shows the apparatus provided with the cooling mechanism which concerns on the 1st Embodiment of this invention. 1 is a schematic cross-sectional view showing an apparatus provided with a cooling mechanism according to a first embodiment of the present invention. It is the schematic of the surface where the heat pipe of the apparatus provided with the cooling mechanism shown in FIG. 1 was exposed. It is a schematic longitudinal cross-sectional view which shows the apparatus provided with the cooling mechanism which concerns on the 2nd Embodiment of this invention. It is a schematic cross-sectional view which shows the apparatus provided with the cooling mechanism which concerns on the 2nd Embodiment of this invention. It is the schematic of the surface where the heat pipe of the apparatus provided with the cooling mechanism shown in FIG. 3 was exposed.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same reference numerals are given to those having the same function, and the description thereof may be omitted.

  FIG. 1A is a perspective view schematically showing an apparatus including a cooling mechanism according to a first embodiment of the present invention. 1B to 1D are schematic cross-sectional views illustrating an apparatus including a cooling mechanism according to a first embodiment of the present invention. Specifically, FIG. 1B is a schematic longitudinal sectional view of a device having a cooling mechanism along the line AA in FIG. 1A, and FIG. 1C shows the cooling mechanism along the line BB in FIG. 1A. FIG. 1D is a schematic cross-sectional side view of the apparatus provided with a cooling mechanism along line CC in FIG. 1A.

  The apparatus 1 including the cooling mechanism illustrated in FIG. 1A includes a heat generating structure 21 including a plurality of heat generating elements 2. The heating element 2 is, for example, a chargeable / dischargeable battery cell, and the heating structure 21 is a battery including a plurality of battery cells. In addition, a lithium ion battery cell is mentioned as a battery cell. The device provided with the cooling mechanism may be incorporated in another device such as an electric vehicle or a hybrid vehicle. The shape, number and arrangement of the heating elements 2 are not particularly limited. In the example of FIG. 1, six plate-shaped heating elements 2 are arranged in one direction.

  In the region 2a between the plurality of heating elements 2, as shown in FIG. 1A, the aluminum block 4 and the aluminum block 4 are connected to each other through a heat conductive sheet 3 formed of a heat conductive material (TIM: Thermal Interface Material). A supported heat pipe 5 is inserted. The heat conductive sheet 3 is bonded in advance to the surface of each heating element 2 facing the other heating elements, and efficiently transmits the heat generated by the heating elements 2 to the heat pipe 5. The heat conductive material for forming the heat conductive sheet 3 can be appropriately selected according to the type of the heating element 2 and the like. For example, when the heating element 2 is an electrical component such as a battery cell, it has electrical insulation. It is desirable to use materials. The heat conductive sheet 3 is not an essential element of the present invention.

  The aluminum block 4 is a support member that supports the heat pipe 5, and is inserted in the region 2 a so as to be in close contact with the heat conductive sheet 3. The aluminum block 4 is provided with an insertion recess or insertion hole (both not shown), and the heat pipe 5 is inserted into the insertion recess or insertion hole. At this time, grease may be applied in advance to the insertion recess or the insertion hole, and the heat pipe 5 may be inserted into the insertion recess or the insertion hole to which the lubricant is applied. The grease is specifically a thermal grease for reducing the thermal resistance from the heating element 2 to the heat pipe 5. In addition, as the support member for supporting the heat pipe 5, a member different from the aluminum block 4 may be used, and as long as the heat pipe 5 can be sandwiched between the heating elements 2, there may be no support member.

  The aluminum block 4 and the heat pipe 5 may be inserted into the plurality of regions 2a, respectively. At this time, the aluminum block 4 and the heat pipe 5 may be inserted in all the areas 2a, or may be inserted only in a part of the areas 2a. In the example of FIG. 1, the aluminum block 4 and the heat pipe 5 are inserted only in three regions 2a. Only the heat conductive sheet 3 is formed in the region 2a where the aluminum block 4 and the heat pipe 5 are not inserted. A plurality of heat pipes 5 may be inserted in the same region 2a. In the example of FIG. 1, at least one heat pipe 5 is inserted into the predetermined region 2 a, a region 2 a in which a plurality of heat pipes 5 are inserted, and a region 2 a in which one heat pipe 5 is inserted. Are mixed.

  The heat pipe 5 is a hollow rod having a hollow portion, and a working fluid such as water or alcohol is sealed in the hollow portion. As shown in FIGS. 1B and 1C, the heat pipe 5 includes an evaporation section 5a that is a first portion extending in the region 2a and a condensing section 5b that is a second portion positioned outside the heat generating structure 21. . In FIG. 1C, only the evaporation section 5a and the condensation section 5b of one heat pipe 5 and the condensation section 5b of the three heat pipes 5 are actually visible, but for the sake of convenience, only the condensation section 5b is visible. The evaporation part 5a of the pipe 5 is also indicated by a dotted line. In FIG. 1D, only the evaporation section 5a and the condensation section 5b of one heat pipe 5 are actually visible, but the evaporation sections 5a of the three heat pipes 5 that are not visible are also shown for convenience.

  The condensing unit 5b extends in a direction different from that of the evaporation unit 5a. That is, the direction in which the evaporator 5a extends and the direction in which the condenser 5b extends intersect. Moreover, in this embodiment, each evaporation part 5a of the several heat pipe 5 is each extended in the position orthogonal to the direction orthogonal to the direction where the evaporation part 5a extends in the in-plane direction of the area | region 2a. For this reason, when viewed from the left and right directions of FIGS. 1B to 1D, the respective evaporation portions 5a of the plurality of heat pipes 5 do not overlap. Each condensing part 5 b of the plurality of heat pipes 5 extends in parallel along the outer surface of the heat generating structure 21. The outer surface of the heat generating structure 21 is a surface connecting the surfaces of the heat generating structure 21 exposed to the outside of the heat generating body 2. By setting it as the structure of this embodiment, the condensation part 5b can be efficiently arrange | positioned on the outer surface of the heat generating structure 21. FIG. The condensing unit 5b is provided with a plurality of fins 6 for radiating heat from the heat pipe 5 into the air. The condensing part 5b and the fin 6 are covered with the duct 7 which forms the flow path through which the air A flows. In FIG. 1A, the duct 7 is omitted.

  FIG. 2 is a diagram for explaining the configuration of the heat pipe 5 and the fins 6 in more detail, and is a schematic diagram showing a surface where the heat pipe 5 is exposed in the apparatus 1 having a cooling mechanism. As shown in FIG. 2, the condensing part 5 b has a bent part 5 b 1 and a straight part 5 b 2, and the straight part 5 b 2 extends to the end of the heat generating structure 21. A plurality of fins 6 are juxtaposed on the straight portion 5b2. The direction of the tip of the condensing part 5B and the length of the condensing part 5B may differ depending on the heat pipe 5. In the example of FIG. 2, as the condensing unit 5B, there are a mixture of one extending in the right direction on the paper surface as the first direction and one extending in the left direction on the paper surface in the second direction opposite to the first direction. Moreover, what has a different length is mixed. At this time, the condensing part 5b is arranged so that the condensing parts 5b of the different heat pipes 5 do not contact each other. The duct 7 is provided so that the air A flows in a direction orthogonal to the direction in which the straight portion 5b2 extends by rotation of a fan (not shown). In addition, the heat conductive sheet 3, the aluminum block 4, the heat pipe 5, the fins 6, and the duct 7 constitute a cooling mechanism 31 that cools the heat generating structure 21.

  With the above configuration, the heat generated in each heating element 2 is transmitted to the evaporation section 5a, which is the first portion extending in the region 2a of the heat pipe 5, via the heat conductive sheet 3 and the aluminum block 4. Due to this heat transfer, the working fluid enclosed in the heat pipe 5 evaporates in the evaporating section 5a and absorbs latent heat (heat of vaporization) along with the evaporation. Thereby, the heat generated in the heating element 2 is absorbed by the heat pipe 5. The evaporated working fluid diffuses and moves in the heat pipe 5 and reaches the condensing part 5b. The working fluid that has reached the condensing unit 5b is cooled and condensed in the condensing unit 5b, and latent heat (condensation heat) is released along with the condensation. The released heat is radiated to the air A flowing in the duct 7. Therefore, the heat generated in each heating element 2 is finally radiated to the air A in the duct 7. At this time, in order to efficiently dissipate the heat generated in the heating element 2, it is important to make the total thermal resistance R, which is the thermal resistance from the surface of the heating element 2 to the condensing part 5b of the heat pipe 5, as small as possible. is there.

Specifically, the total thermal resistance R can be expressed as R = R _{TIM +} R _A + R _e + R _c + R _f . R _TIM is the thermal resistance of the heat conductive sheet 3, _RA is the thermal resistance of the aluminum block 4, R _e is the thermal resistance of the evaporation part 5 a of the heat pipe 5, R _c is the thermal resistance of the condensing part 5 b of the heat pipe 5, R _f is the thermal resistance of the fin 6. Further, the thermal resistance R _c of the condensing unit 5b can be expressed as R _c = 1 / (α _c · A _c ). Here alpha _c is the heat transfer coefficient of the condenser section 5b, the A _c is the internal surface area of the condenser portion 5b. The inner surface area _Ac of the condensing part 5b becomes larger as the condensing part 5b is longer. For example, when the inner diameter of the heat pipe 5 is constant, the inner surface area Ac of the condensing part 5b is represented by the product of the circumference, the inner diameter of the heat pipe 5, and the length of the condensing part 5b. For this reason, the longer the condensing part 5b is, the smaller the thermal resistance Rc of the condensing part 5b is. As a result, the total thermal resistance R is also reduced, so that the heat generated in the heating element 2 can be efficiently radiated.

  In the present embodiment, the condensing part 5b of the heat pipe 5 extends in a direction different from the evaporation part 5a extending through the region 2a between the plurality of heating elements 2, so that even if the condensing part 5b is lengthened, the heat generating structure It becomes possible to suppress the cooling mechanism 31 from becoming longer in the direction away from the body 21. Therefore, it is possible to improve the cooling capacity while saving space.

  Further, when an air-cooling type cooling mechanism is used as a cooling mechanism for cooling the heat generating structure 21, the heat generating structure 21 is cooled only by the wind from the fan provided in the duct. The cooling by is stopped. On the other hand, in the present embodiment, since the heat pipe type cooling mechanism 31 is used, even if the fan stops, the condensing part 5b is cooled by the air in the duct 7 and the natural working fluid in the heat pipe 5 is cooled. Due to the occurrence of convection, cooling of the heat generating structure 21 by the heat pipe 5 continues. For this reason, even in the situation where the fan is stopped when the heat generating structure 21 is at a high temperature, the heat generating structure 21 can be quickly cooled in the present embodiment. For example, in the case where the heat generating structure 21 is a lithium ion battery used in a hybrid vehicle or an electric vehicle, if an air-cooling type cooling mechanism is used, it takes 4 hours until the lithium ion battery reaches room temperature after the vehicle stops. However, in this embodiment, since the heat pipe type cooling mechanism 31 is used, about 2 hours is sufficient until the lithium ion battery reaches room temperature after the automobile stops.

  Further, even in a situation where the heat generating structure 21 generates heat while the fan is stopped, the temperature rise of the heat generating structure 21 can be suppressed. For example, since a lithium ion battery does not generate much heat during normal charging, the fan is stopped during charging in a hybrid vehicle or an electric vehicle. However, when a lithium ion battery is rapidly charged, the lithium ion battery may generate heat. In this case, if an air-cooling type cooling mechanism is used and the fan is stopped, the lithium ion battery becomes hot, and problems such as being unable to run the automobile immediately after rapid charging occur. In addition, if the fan is operated during the rapid charging of the lithium ion battery, power is consumed and the charging time becomes long. On the other hand, in this embodiment, since the heat pipe type cooling mechanism 31 is used, it is possible to suppress the lithium ion battery from reaching a high temperature without operating the fan. Charging is possible, and it is possible to drive the vehicle quickly after rapid charging.

  In addition, when an air-cooling type cooling mechanism is used and a fan fails during driving of the automobile, the lithium ion battery becomes in a high temperature state, and as a result, the automobile or the lithium ion battery may malfunction. In this embodiment, since cooling can be maintained even if a fan breaks down, it is possible to suppress the occurrence of problems in automobiles and lithium ion batteries.

  Next, a second embodiment will be described. 3A, 3B, and 4 are schematic views showing an apparatus including a cooling mechanism according to a second embodiment of the present invention. Specifically, FIG. 3A is a schematic longitudinal cross-sectional view of the device 1 having a cooling mechanism, FIG. 3B is a schematic cross-sectional view of the device 1 having a cooling mechanism, taken along line DD in FIG. These are figures which show the surface where the heat pipe 5 in the apparatus 1 provided with the cooling mechanism was exposed.

  The apparatus 1 having the cooling mechanism shown in FIGS. 3A, 3B and 4 has the same configuration as the apparatus 1 having the cooling mechanism of the first embodiment shown in FIGS. 1A to 1D and FIG. The shape of the condensing part 5b of the heat pipe 5 is different from that of the first embodiment. In the first embodiment, the condensing part 5b has one bent part 5b1, but in the present embodiment, the condensing part 5b has a plurality of bent parts 5b1. Specifically, the condensing unit 5b bends in a direction along the outer surface of the heat generating structure 21 at a portion exposed from the heat generating structure 21, and further bends in a U shape at one end of the heat generating structure 21. It extends to the other end of the heat generating structure 21. As in the first embodiment, a plurality of fins 6 are arranged in parallel in the straight line portion 5b2. In FIG. 3B, only the evaporation section 5a and the condensation section 5b of one heat pipe 5 are actually visible, but the evaporation sections 5a of the three heat pipes 5 that are not visible are also shown for convenience.

  According to the second embodiment, since the condensing part 5b has a plurality of bent parts 5b1, the condensing part 5b can be further lengthened without increasing in the direction away from the heat generating structure 21. This makes it possible to further improve the cooling capacity.

  In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

DESCRIPTION OF SYMBOLS 1 Apparatus provided with cooling function 2 Heat generating element 3 Thermal conductive sheet 4 Aluminum block 5 Heat pipe 5a Evaporating part 5b Condensing part 5b1 Bending part 5b2 Straight part 6 Fin 7 Duct 21 Heating structure 31 Cooling mechanism

Claims (2)

A cooling mechanism for a heating structure including a plurality of heating elements,
A plurality of heat pipes having a first portion extending in a region between the plurality of heating elements and a second portion located outside the heating structure;
The second portion extends along an outer surface of the heat generating structure in a direction different from that of the first portion. The heat generating structure includes a plurality of regions, and each of the plurality of regions includes at least one of the regions. The first portion of the two heat pipes extends;
The second portions of each of the plurality of heat pipes extend in parallel to each other, and each of the first portions of the heat pipe is in an in-plane direction of the region and the extending direction of the first portion. Extending in different positions with respect to the orthogonal direction,
The plurality of heating elements are arranged in one direction, each of the second portions of the plurality of heat pipes extends in the one direction, and a plurality of the heat pipes have tips of the second portions. Cooling of a heat generating structure, wherein the heat pipe is oriented in a first direction and the heat pipe is oriented in the second direction opposite to the first direction. mechanism.   The cooling mechanism according to claim 1, wherein the second portion has a plurality of bent portions.

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