JP2021188810A - Self-oscillating heat pipe, cooling device, and power conversion device - Google Patents

Abstract

To provide a self-oscillating heat pipe, a cooling device, and a power conversion device that have a simple structure with good productivity, improve a joining state of a heat receiving part, and have good cooling performance.SOLUTION: A self-oscillating heat pipe comprises: a plurality of multiple flow passage structure bodies 8 comprising a plurality of pipe inside flow passages filled with working liquid; a first end part side sealing member joined to one end part of the multiple flow passage structure bodies 8, and comprising a communication flow passage connecting the pipe inside flow passages; and a second end part side sealing member 9 joined to the other end part of the multiple flow passage structure bodies 8, and comprising a communication flow passage connecting the pipe inside flow passages.SELECTED DRAWING: Figure 2

Description

The present invention relates to a self-excited oscillating heat pipe, a cooling device and a power conversion device.

A self-excited oscillating heat pipe generally has a small-diameter flow path having a diameter on the order of millimeters, and a hydraulic fluid is provided in a state where liquid columns and air columns are alternately present in the small-diameter flow path due to surface tension. Is enclosed. A plurality of heat receiving parts (high temperature parts) and heat radiating parts (low temperature parts) are alternately provided along the small diameter flow path. The liquid column and the air column vibrate self-excitedly, whereby heat can be transferred between the heat receiving section and the heat radiating section.

Unlike general heat pipes, self-excited oscillating heat pipes do not require reflux due to gravity, so they have the advantage of having a high degree of freedom in the installation posture. Further, since the heat transfer performance can be maintained even if the diameter of the flow path is made smaller than that of a general heat pipe, there is an advantage that the size can be reduced.

In Patent Document 1, a closed flow path is formed by sandwiching a plurality of straight flat tubes each having a plurality of flow paths between two fluid distribution elements, and the heat transfer element (heat receiving block) is formed in the longitudinal direction of the flat tube. A self-excited oscillating heat pipe having a structure in which a part of the heat pipe is inserted is described.

European Patent Publication No. 2857783

The inventor of the present application has obtained the following findings as a result of diligent studies on the problems in applying the self-excited oscillating heat pipe to the cooling device of the power conversion device mounted on a moving body such as a railroad vehicle.

In the self-excited oscillating heat pipe, if there are multiple heat receiving parts in the flow path where the amount of heat received is extremely small or none at all compared to other heat receiving parts, the heat receiving parts and the heat radiating parts may exist alternately. It is not realized, and there is a problem that the variation in the amount of heat received causes the variation in the length of the liquid column and the bias in the liquid distribution, and the self-excited vibration is hindered. For example, when a long flat tube is bent a large number of times and remolded, and the bent portion of the flat tube is joined to a heat receiving plate to form a self-excited oscillating heat pipe, the bending height of the flat tube varies and the heat receiving plate is affected. Due to the variation in the flatness of the flat tube, the joint state may deteriorate. If the bonding state varies, the amount of heat received at the poorly bonded portion becomes small, and the self-excited vibration is hindered for the reasons described above. Furthermore, since heat is locally applied to a part with a good joint condition, the heat receiving part is always filled with steam and fluid is not supplied, so-called dryout is likely to occur, and the cooling performance of the self-excited oscillating heat pipe deteriorates. Is a concern.

Further, the self-excited oscillating heat pipe tends to have less gravity dependence as the number of high temperature portions and low temperature portions in contact with the flow path increases. When increasing the number of reciprocating flow paths in a limited size such as a device mounted on a moving body such as a railroad vehicle, for example, a method of reducing the bending pitch of a flat pipe can be considered. However, since it is necessary to prevent the flat tube from being damaged, the number of round trips in the flow path is limited. Further, if the bending pitch is small, it is difficult to provide a flat surface in the bent portion, so that the joint surface with the heat receiving plate becomes small and the difficulty of joining increases.

Further, in the self-excited vibration heat pipe, the hydraulic fluid enclosed in the flow path self-excited and vibrates due to the pressure difference caused by the pressure increase due to boiling or evaporation in the heat receiving part and the pressure decrease due to condensation in the heat dissipation part. In order to cause an imbalance in the pressure in the path, the startability and cooling performance of the working fluid are improved by providing a portion where the amount of heat received or the amount of heat dissipated is unbalanced as compared with the others. As a method of making the amount of heat received and the amount of heat dissipated unbalanced, for example, it is conceivable to change the flat tube pitch and height. Since it is required separately, the degree of freedom in optimal design is limited.

In addition, power conversion devices such as railroad vehicles, which are an example of moving objects, are often installed under the floor together with other on-board equipment, and it is necessary to keep the vehicle's mounting limits, so space restrictions are severe. many. Further, since the power conversion device handles a large amount of power, the number of semiconductor elements required for power conversion is relatively large, and the amount of heat generated tends to be large. For these reasons, the cooling device for the power conversion device is required to have a large heat receiving area, high cooling performance, and a smaller size.

For example, in the configuration as in Patent Document 1, if the flat tube (fin and heat receiving block) is expanded in the longitudinal direction or the lateral direction in order to improve the cooling performance, the aspect ratio of the cooling device becomes large, so that the mounting limit is limited. It is difficult to improve the cooling performance while protecting it. In addition, when semiconductor elements are arranged in a row and electrically connected to surrounding electronic devices (for example, capacitors) by a bus bar, the distance from the electronic devices varies, which may cause current imbalance. be.

In order to avoid such a problem, when a plurality of rows of semiconductor elements are arranged, it is necessary to expand the heat receiving block in the longitudinal direction of the flat tube, which causes an increase in the weight and size of the cooling device. It is also conceivable to arrange semiconductor elements on both sides of the heat receiving block, but in this configuration, the bus bar must be U-shaped, for example, and a dead space is created when combining with an electronic device, resulting in a power conversion device. There is also the problem that miniaturization becomes difficult as a whole.

Further, in the configuration of Patent Document 1, there is also a problem that the flat tube is fitted in the heating block over a relatively long distance, whereby the heat flux from the heating block to the flat tube is increased and dryout is likely to occur. be. In addition, due to its configuration, the cooling performance is biased due to the temperature distribution in the flat tube, which is not preferable for use in a cooling device, and the configuration must be enlarged in order to have sufficient cooling performance as a whole. It doesn't become.

It is an object of the present invention to provide a small self-excited oscillating heat pipe, a cooling device and a power conversion device having a simple structure with good productivity, a good bonding state of heat receiving portions, and good cooling performance. And.

In order to solve the above problems, one of the typical self-excited vibration heat pipes according to the present invention is a plurality of multi-channel structures having a plurality of in-pipe channels filled with a working fluid, and the multi-channel structure. A first end-side sealing member provided with a communication flow path that is joined to one end of the body and connects the in-pipe flow paths of the adjacent double flow path structures, and the other of the double flow path structures. It is achieved by having a second end-side sealing member, which is joined to the end of the structure and has a communication flow path connecting the in-pipe flow paths of the adjacent double flow path structure.

According to the present invention, since the heat receiving plate joint surface is flat, a small self-excited oscillating heat pipe, a cooling device, and a power conversion device, which have a good joint state between the heat receiving plate and the flat tube and have good cooling performance, are provided. can do.
Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 1 is a view of the power conversion device mounted on the moving body (railroad vehicle) in the first embodiment as viewed from the traveling direction. FIG. 2 is a perspective view showing a cooling device provided with a self-excited oscillating heat pipe according to the first embodiment. FIG. 3 is a perspective view showing one unit of the self-excited oscillating heat pipe in the first embodiment. FIG. 4 is an exploded view of the self-excited oscillating heat pipe 1 unit in the first embodiment. FIG. 5 is a cross-sectional view taken along the line A in FIG. 3 showing an example of the flow path structure of the multi-hole flat pipe constituting the self-excited oscillating heat pipe in the first embodiment. FIG. 6 is a cross-sectional view taken along the line CC in FIG. 5 showing the flow path structure of the multi-hole flat pipe constituting the self-excited oscillating heat pipe in the first embodiment. FIG. 7 is a cross-sectional view of the first slit of the self-excited oscillating heat pipe in the first embodiment. FIG. 8A is a cross-sectional view of the second slit of the self-excited oscillating heat pipe in the first embodiment. FIG. 8B is a cross-sectional view of the third slit of the self-excited oscillating heat pipe in the first embodiment. FIG. 9 is a cross-sectional view of the heat receiving portion side top plate or the heat radiating portion side top plate of the self-excited oscillating heat pipe in the first embodiment. FIG. 10A is a cross-sectional view taken along the line B in FIG. 4, showing a connecting structure of a self-excited oscillating heat pipe end portion in the second embodiment. FIG. 10B is a cross-sectional view taken along the line B in FIG. 4, showing the connecting structure of the self-excited oscillating heat pipe end portion in the second embodiment. FIG. 11 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the third embodiment. FIG. 12 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the fourth embodiment. FIG. 13 is a cross-sectional view showing the flow path structure of the heat receiving portion side connecting flow path member of the self-excited oscillating heat pipe cooling device according to the fourth embodiment. FIG. 14 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the fifth embodiment. FIG. 15 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the sixth embodiment. FIG. 16 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the seventh embodiment. FIG. 17 is a perspective view showing a self-excited oscillating heat pipe cooling device according to the eighth embodiment. FIG. 18 is an exploded perspective view showing a heat receiving plate structure of the self-excited oscillating heat pipe cooling device according to the ninth embodiment. FIG. 19 is a diagram showing the positional relationship of the self-excited oscillating heat pipe cooling device, the bus bar, and the condenser (electrical component) in the power conversion device for the moving body as seen from the upper surface side of the moving body in the tenth embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification, the "multi-channel structure" is a structure having a plurality of channels in which each axis is arranged along a predetermined direction, and at least one end of each channel is open. To say. The predetermined direction is referred to as a flow path parallel direction, and the longitudinal direction of the double flow path structure is referred to as a flow path straight direction. The multi-hole flat tube described below is an example of a multi-channel structure.

[Embodiment 1]
FIG. 1 is a view of the power conversion device mounted on a railway vehicle as a mobile body in the present embodiment as viewed from the traveling direction. The power conversion device 1 is installed under the floor of the railway vehicle 2 and has a function of controlling the rotation speed of the electric motor by changing the frequency of the electric power supplied to the electric motor (not shown) that drives the railway vehicle 2. .. Inside the power conversion device 1, a plurality of semiconductor elements 3 constituting a power conversion circuit and an electric component group 4 are installed. The semiconductor element 3 causes heat loss when it is energized and when it is switched on / off, and the heat generated at this time dissipates heat to become a heating source (heating element). Since the characteristics of the semiconductor element 3 may deteriorate due to overheating and the product life may be shortened, a cooling device 5 is usually attached to cool the semiconductor element 3 in order to avoid these problems.

The cooling device 5 dissipates heat generated from the semiconductor element 3 when the traveling wind 10 generated when the railway vehicle 2 travels is supplied in the direction perpendicular to the paper surface of FIG. 1, thereby performing air cooling. Since the railroad vehicle 2 moves in either the front-rear direction, the traveling wind 10 is generated in the direction accompanying the movement. The semiconductor element 3 is, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effective Transistor), or the like.

The cooling device 5 will be described. FIG. 2 is a perspective view showing the cooling device 5 in the present embodiment, FIG. 3 is a perspective view showing a self-excited oscillating heat pipe 6 for one unit, and FIG. 4 is an exploded view of the self-excited oscillating heat pipe 6. In FIG. 3, the direction in which the multi-hole flat tube 8 travels straight through the flow path is indicated by an arrow 30, the parallel direction of the flow path of the multi-hole flat tube 8 is indicated by an arrow 31, and the alignment direction of the multi-hole flat tube 8 is indicated by an arrow 32.

The cooling device 5 is composed of a heat receiving plate 12, a multi-hole flat tube 8, a corrugated fin 11, a heat receiving portion side flat tube end sealing member 7, and a heat radiating portion side flat tube end sealing member 9. The heat receiving plate 12, the multi-hole flat tube 8, and the corrugated fin 11 are made of, for example, a metal such as an aluminum alloy or copper. A plurality of semiconductor elements 3 are fixed to one surface of the heat receiving plate 12 by screws or the like (not shown) via a member (not shown) such as grease. A plurality of self-excited oscillating heat pipes 6 are joined to the other surface of the heat receiving plate 12 by brazing or the like.

The self-excited oscillating heat pipe 6 includes a plurality of straight elongated multi-hole flat pipes 8, a heat receiving portion side flat pipe end sealing member (first end side sealing member) 7, and a heat radiating portion side flat pipe. It has an end sealing member (second end side sealing member) 9. Although the details will be described later, the heat receiving portion side flat tube end sealing member 7 alternately joins the upper ends of the adjacent multi-hole flat pipes 8 to form a communication flow path 15 (FIG. 8A), and also has a heat dissipation portion. The side flat tube end sealing member 9 alternately joins the lower ends of adjacent multi-hole flat tubes 8 to form a communication flow path 15 (FIG. 8B). It is preferable that the end surface of the multi-hole flat tube 8 is a plane orthogonal to the longitudinal direction.

In the present embodiment, when n is an integer of 1 or more, the (2n-1) th multi-hole flat tube 8, the (2n) th multi-hole flat tube 8, and the (2n + 1) th multi-hole flat tube 8 are used. The pipes 8 are provided in parallel in this order, and the upper end (or lower end) of the (2n-1) th multi-hole flat pipe 8 and the (2n) th multi-hole flat pipe 8 form a communication flow path 15. The lower end (or upper end) of the (2n) th multi-hole flat tube 8 and the (2n + 1) th multi-hole flat tube 8 communicate with each other via the communication flow path 15. As a result, the hydraulic fluid can move from the flow path in the multi-hole flat tube 8 and the communication flow path 15 of the flat tube end sealing member 7 on the heat receiving portion side and the flat tube end sealing member 9 on the heat radiating portion side. A closed closed flow path is formed. This closed flow path meanders in a rectangular wave shape (alternately bent as it travels along the closed flow path).

In the self-excited oscillating heat pipe 6, the corrugated fins 11 are joined by brazing or the like so as to connect the facing surfaces of the multi-hole flat pipes 8 arranged in parallel to each other. A traveling wind 10 is supplied between the self-excited oscillating heat pipe 6 and the corrugated fins 11 to exchange heat and dissipate heat. With such a configuration, the self-excited oscillating heat pipe 6 is provided with heat receiving portions and heat radiating portions alternately.

The internal structure of the self-excited oscillating heat pipe 6 will be described. FIG. 5 shows the flow path structure of the self-excited oscillating heat pipe in the present embodiment, and a cross-sectional view taken along the line A of the portion surrounded by the dotted line in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. ..
Inside the multi-hole flat tube 8, a plurality of flow paths (in-pipe flow paths) 13 partitioned by the partition wall 14 are arranged in parallel. The cross-sectional shape of each flow path 13 is rectangular or circular, the cross-sectional dimension of each flow path 13 and the thickness of the partition wall 14 are on the order of millimeters, and the length of each flow path 13 is sufficiently longer than the flow path diameter. At the end of the multi-hole flat tube 8, a heat receiving portion side flat tube end sealing member (first end sealing member) 7 having a communication flow path and a heat radiating portion side flat tube end sealing member (first) The end sealing member of 2) is joined, and the flow path 13 inside the multi-hole flat tube 8 communicates with each other by the communication flow path 15 (FIGS. 8A and 8B). When there are four or more multi-hole flat tubes 8, the heat receiving portion side flat tube end sealing member 7 and / or the heat radiating portion side flat tube end sealing member 9 is the flow path 13 of the two multi-hole flat tubes 8. It is possible to have a first communication flow path 15 communicating with the communication flow path 15 and a second communication flow path 15 communicating with the flow path 13 of another two multi-hole flat pipes 8.

A predetermined amount of a working liquid (not shown) is sealed in the sealed flow path 13 and the communication flow path 15 of the self-excited oscillating heat pipe 6. As the working liquid, for example, hydrocarbons such as water, alcohols and butane, hydrofluorocarbons, hydrofluoroethers, hydrofluoroolefins, perfluoroketones and the like can be used.

The flat tube end sealing member 7 on the heat receiving portion side and the flat tube end sealing member 9 on the heat radiating portion side will be described. 7 to 9 are examples of the end sealing member in the present embodiment, FIG. 7 is a cross-sectional view of the first slit plate, FIG. 8 is a cross-sectional view of the second and third slit plates, and FIG. It is a cross-sectional view of the top plate on the portion side and the heat radiation portion side, and is the cross-sectional view taken along the line B of the portion surrounded by the dotted line in FIG. In FIG. 7, the longitudinal direction of the slit plate is indicated by an arrow 33 (32), and the lateral direction of the slit plate is indicated by an arrow 34 (31).

The heat receiving portion side flat tube end sealing member 7 is composed of, for example, a first slit plate (interval holding plate) 16, a second slit plate (flow path communication plate) 17, and a heat receiving portion side top plate 19, and dissipates heat. The portion-side flat tube end sealing member 9 is composed of a first slit plate (interval holding plate) 16, a third slit plate (flow path communication plate) 18, and a heat dissipation portion side top plate 20. The flat tube end sealing member 7 on the heat receiving portion side or the flat tube end sealing member 9 on the heat radiating portion side may be an integral part. Further, the slit plate and the top plate may be integrated parts, for example, the first slit plate 16 and the second slit plate 17, the first slit plate 16 and the third slit plate 18, and the second slit plate 17. A combination of the heat receiving portion side top plate 19, the third slit plate 18, the heat radiating portion side top plate 20, and the like may be used as an integrated component. In this case, the heat receiving portion side top plate 19 may be used as the heat receiving plate.
The first slit plate 16 has a role of aligning and holding the multi-hole flat tube 8 in parallel, and has the same size as the outer peripheral shape of the end of the multi-hole flat tube 8 so that the multi-hole flat tube 8 can be inserted. It has a plurality of slit openings 16a at equal pitches. Further, it has a role of covering the openings 17a and 18a of the second slit plate 17 and the third slit plate 18, respectively, and sealing the flow path 13. Here, the first slit plate 16 is preferably made thick in order to improve the strength of the base of the multi-hole flat tube 8.

The second slit plate 17 and the third slit plate 18 have openings 17a and 18a connecting the flow path 13 inside the multi-hole flat tube 8 and the flow path of at least one adjacent multi-hole flat tube, respectively. .. Here, the openings 17a and 18a of the second slit plate 17 and the third slit plate 18 are alternately provided in the cross section seen by the arrow B so that the flow path of the self-excited oscillating heat pipe 6 meanders in a rectangular wave shape. Be done. The second slit plate 17 and the third slit plate 18 may be the same and may be used in different directions. Here, the openings 17a and 18a of the second slit plate 17 and the third slit plate 18 may connect a plurality of adjacent multi-hole flat tubes 8.

Further, the length of the slit plate in the openings 17a and 18a of the second slit plate 17 and the third slit plate 18 in the longitudinal direction 33 is set to the length of the opening 16a of the first slit plate 16 (that is, the multi-hole flat tube 8). The length is shorter than the length of (width), and a step is provided between the first slit plate 16 and the second slit plate 17 to align the multi-hole flat tube 8 with the end sealing member. You may use it. An opening for injecting a working liquid may be formed in the second slit plate 17 and the third slit plate 18.

The heat receiving portion side top plate 19 and the heat radiating portion side top plate 20 cover the openings 17a and 18a of the second slit plate 17 and the third slit plate 18, respectively, and have a role of sealing the flow path 13. Here, the communication flow path 15 is formed by the openings 17a and 18a, and the heat receiving portion side top plate 19 and the heat radiating portion side top plate 20 covering the openings 17a and 18a. The heat receiving portion side top plate 19 and the heat radiating portion side top plate 20 may have a hydraulic fluid injection pipe (not shown). Further, when the flow path is sealed with the heat receiving plate 12, it is not necessary to provide the heat receiving portion side top plate 19. Further, a plurality of self-excited vibration heat pipes 6 may be arranged on one heat receiving plate 12.

The first slit plate 16, the second slit plate 17, and the third slit plate 18 are formed by, for example, punching, extrusion, and cutting. Each slit plate, top plate, and heat receiving plate are joined by, for example, brazing or soldering. Flux may be applied to the joint surface.

The effect of the first embodiment will be described. According to the present embodiment, the joint surfaces of the first slit plate 16, the second slit plate 17, the third slit plate 18, the heat receiving portion side top plate 19, the heat radiating portion side top plate 20, and the heat receiving plate 12 are flat. Therefore, in addition to stabilizing the bonding quality, the heat input from the heat receiving plate 12 becomes uniform by making the bonding area uniform, so that the cooling performance is improved. Further, since the multi-hole flat tube 8 is used as it is, unlike the bent structure in which the multi-hole flat tube is bent, the total length can be easily adjusted, the processing difficulty can be reduced, and the cost can be reduced.

Further, since the flow paths in the multi-hole flat tube 8 are connected by each heating portion (the surface in contact with the heat receiving plate) and the liquid is easily distributed evenly between the flow paths in the multi-hole flat tube 8, one stroke is written. Compared to the meandering flow path structure, there is less liquid bias and the cooling performance is good.

In general, the self-excited oscillating heat pipe becomes less dependent on gravity as the number of flow path turns increases. As a method of increasing the number of flow path turns, for example, the number of multi-hole flat tubes can be increased. As a result, the heat dissipation area is expanded, and the cooling performance is also improved.

In particular, the cooling device mounted on a moving body such as a railroad vehicle is installed under the floor together with various other electric parts, so that the installation space is limited. In order to increase the number of multi-hole flat tubes in a limited space, it is necessary to narrow the arrangement pitch of the multi-hole flat tubes. However, in a bending structure such as bending a multi-hole flat tube, there is a minimum limit value of the bending pitch in which the multi-hole flat tube is not damaged and the internal flow path is not deformed, so that the number of times of bending is limited. Further, if the bending pitch is made small, it is difficult to provide a flat surface in the bent portion, and the difficulty of brazing and joining increases. On the other hand, in the present embodiment, the heat receiving surface remains flat even if the pitch of the multi-hole flat tube 8 is reduced, so that brazing joining is easy. This makes it possible to manufacture a cooling device equipped with a self-excited oscillating heat pipe that is smaller and has higher cooling performance.

Further, in the straight structure as in the conventional case (Patent Document 1), since the multi-hole flat tube is arranged perpendicular to the heat receiving surface of the semiconductor element in the lateral direction, the semiconductor is used in each flow path in the multi-hole flat tube. There is a difference in the heat transfer distance from the element. Since the flow path on the side close to the semiconductor element is locally heated, the liquid may be biased in the flow path in the multi-hole flat tube, and the cooling performance may deteriorate. In addition, the multi-hole flat tube is fitted into the heating block over a relatively long distance, which increases the heat flux from the heating block to the flat tube and facilitates dryout. Further, in the straight structure as in the conventional case (Patent Document 1), since the semiconductor element is arranged horizontally with respect to the heat transfer direction of the self-excited vibration heat pipe, it has a temperature distribution in the heat transfer direction. In this case, since it is necessary to design the cooler so that it is sufficiently cooled even at the highest temperature point of the semiconductor element, higher cooling performance is required as compared with the case where the temperature distribution of the semiconductor element is uniform, and the cooler The size increases. In addition, the larger the heat load, the faster the deterioration, and the shorter the life of the semiconductor element.

On the other hand, in the present embodiment, the multi-hole flat tube 8 is arranged horizontally in the lateral direction with respect to the heat receiving surface of the semiconductor element, and the semiconductor element is perpendicular to the heat transfer direction of the self-excited vibration heat pipe 6. Is arranged, the heat transfer distance from each flow path 13 in the multi-hole flat tube 8 to the semiconductor element 3 is the same, and since there is no locally heated part, dryout is unlikely to occur and cooling performance is improved. do. Further, since the temperature distribution does not occur in the semiconductor element, the cooler can be miniaturized and the life of the semiconductor element is long. In particular, in the heat receiving portion side flat tube end sealing member 7 in contact with the heat receiving plate 12, the connecting flow path 15 through which the fluid passes has a flat space shape orthogonal to the flow path 13, and is a distance from the heat receiving plate 12. Is uniform, so that the amount of heat received (heat flux from the heat receiving plate 12) is uniform in the entire flow path 13, local heating is suppressed, and the liquid distribution in the flow path is uniform. Dryout is less likely to occur compared to the configuration of.

Further, in the conventional straight structure (Patent Document 1), since the structure receives heat from the periphery of the multi-hole flat tube (for example, the multi-hole flat tube is inserted into the heat receiving block), the multi-hole flat tube is used when the cooling performance is improved. When the tube is expanded in the lateral direction (direction in which the flow path is aligned in the multi-hole flat tube), the heat receiving block needs to be thickened accordingly, and the mass increases. On the other hand, in the present embodiment, since the contact surface between the heat receiving plate 12 and the multi-hole flat tube 8 is the longitudinal end of the multi-hole flat tube 8, the heat receiving plate 12 is adapted to the expansion of the width of the multi-hole flat tube 8. The weight can be reduced without the need to increase the thickness.

[Embodiment 2]
10A and 10B correspond to the portions surrounded by the dotted line in FIG. 4, respectively, showing an example of the cross-sectional view of the second slit plate 17 and the third slit plate 18 of the self-excited oscillating heat pipe in the second embodiment. It is a cross-sectional view taken along the line B. As a difference from the first embodiment, in the present embodiment, the openings of the second slit plate 17 and the third slit plate 18 are divided into a plurality of parts with respect to the flow path in the multi-hole flat pipe 8. A plurality of self-excited oscillating heat pipes having a flow path turn meandering in a rectangular shape are formed.

More specifically, when m is an integer of 1 or more, the (2m-1) th flow path 13 and (2m-1) th flow path 13 along the longitudinal direction of the second slit plate 17 and the third slit plate 18. The 2m) th flow path 13 and the (2m + 1) th flow path 13 are provided in parallel in this order, and the (2m-1) th flow path 13 and the upper end of the (2m) th flow path 13 are provided in parallel. (Shown in FIG. 10A) communicate with each other via the communication flow path 15, and the (2m) th flow path 13 and the lower end of the (2m + 1) th flow path 13 (shown in FIG. 10B) communicate with each other through the communication flow path 15. Communicate through. Further, in the (2 m) th flow path 13 adjacent to the second slit plate 17 and the third slit plate 18 in the lateral direction, the upper end of one of the flow paths 13 is the (2 m-1) th flow path 13. When communicating with the upper end of the other flow path 13, the upper end of the other flow path 13 communicates with the upper end of the (2m + 1) th flow path 13. The same applies to the lower end of the flow path 13. With such a configuration, the same effect as that of the first embodiment can be obtained.

Furthermore, since there are multiple independent channels containing the hydraulic fluid, for example, when the condenser is mounted under the floor of a moving object such as a railroad vehicle, if a part of the cooler is damaged due to a collision of flying objects or the like. However, the damage caused by the leakage of the hydraulic fluid can be limited to the flow path at the collision point, and the deterioration of the performance of the entire cooler can be suppressed to a small extent. In addition, in order to maintain the strength of the second slit plate 17 and the third slit plate 18, openings (communication flow paths) may be provided alternately in the flow path direction in the multi-hole flat tube 8. Further, the flow path in the multi-hole flat tube 8 located at the end of the second slit plate 17 and the third slit plate 18 is extended to form a flow path for injecting the hydraulic fluid, and a cap with an injection tube or the like is formed. It may be joined and sealed, and then sealed by crushing the pipe. Further, instead of using the first, second, and third slit plates, the flow path turn portion on the heat receiving portion side and the heat radiating portion side may be configured by one member.

[Embodiment 3]
FIG. 11 is a perspective view showing the cooling device in the third embodiment, but is shown so that the heat receiving plate 12 is located below. As a difference from the first embodiment and the second embodiment, in the present embodiment, the multi-hole flat pipe 22 having a shorter length (preferably 1/2 or less) than the multi-hole flat pipe 8 is provided at the end of the self-excited oscillating heat pipe 6. Is arranged, one is joined to the heat receiving portion side flat tube end sealing member 7, and the other is joined by a cap 21 with an injection tube to seal. The cap 21 with an injection tube has an injection tube 21a capable of injecting a working liquid from the outside. According to the present embodiment, the same effect as that of the first embodiment can be obtained.

In addition, according to the present embodiment, since the short multi-hole flat pipe 22 is provided, the corrugated fin 11 between the multi-hole flat pipes 8 and the corrugated to be joined to the multi-hole flat pipe 8 and the multi-hole flat pipe 22. The difference in surface area from the fin 11 and the difference in surface area between the multi-hole flat tube 8 and the cap 21 with an injection tube and the multi-hole flat tube 22 cause an imbalance in heat dissipation capacity. As a result, imbalance of pressure in the flow path 13 is likely to occur, so that the startability and cooling performance of the working fluid are improved. Further, by crushing the injection pipe 21a, the self-excited oscillating heat pipe can be sealed. When the injection pipe 21a is crushed, the crushing tool (not shown) does not interfere with the heat receiving plate 12, so that workability is good. Here, the cap 21 with an injection tube may be manufactured as an integral part by, for example, forging. Further, the injection tube and the cap may be processed separately and joined by brazing or the like. Further, all or a part of the adjacent self-excited oscillating heat pipes 6 may be collectively sealed by one cap 21 with an injection pipe.

[Embodiment 4]
FIG. 12 is a perspective view showing the cooling device in the fourth embodiment, but is shown so that the heat receiving plate 12 is located below. FIG. 13 is a cross-sectional view of the flow path of the second slit plate 17, and shows the vicinity of the joint side end portion of the cap 21 with an injection pipe. As a difference from the first to third embodiments, in the present embodiment, the heat receiving portion side flat tube end sealing member 7 including the second slit plate 17 is long in the alignment direction of the multi-hole flat tube 8 and is a heat receiving plate. The second slit plate 17 is arranged so as to protrude from 12, and has a hydraulic fluid injection flow path 23 that communicates the communication flow path 15 and the outside, and a cap 21 with an injection tube is provided at the outer end thereof. It is joined. Even in such a configuration, the same effect as that of the first embodiment can be obtained. Further, when the injection pipe 21a is crushed and sealed, the crushing tool (not shown) does not interfere with the heat receiving plate 12, so that the workability is good.

[Embodiment 5]
FIG. 14 is a perspective view showing the cooling device in the fifth embodiment, but is shown so that the heat receiving plate 12 is located below. As a difference from the first to fourth embodiments, in the present embodiment, the heat receiving portion side flat tube end sealing member 7 including the second slit plate 17 is long in the alignment direction of the multi-hole flat tube 8 but is a heat receiving plate. A hydraulic fluid injection flow path 23 (see FIG. 13) that does not protrude from 12 and communicates between the internal communication flow path and the outside is provided, and a cap 21 with an injection tube is joined to the outer end portion thereof. There is. A recess (a wide groove extending in the alignment direction of the multi-hole flat tube 8) 24 is formed on the surface of the heat receiving plate 12, and the heat receiving portion side flat tube end sealing member 7 including the cap 21 with an injection tube is placed in the recess 24. It is housed and placed in. Even in such a configuration, the same effect as that of the first embodiment can be obtained.

Further, after the injection tube 21a is crushed and sealed, the crushing tool (not shown) receives heat by mounting the heat receiving portion side flat tube end sealing member 7 including the cap 21 with the injection tube in the recess 24. It does not interfere with the plate 12 and has good workability. Further, when the power conversion device including the cooling device according to the fifth embodiment is attached to a railroad vehicle or the like, the injection pipe 21a is hidden in the recess 24 of the heat receiving plate 12 with respect to the traveling direction of the vehicle, so that the flying object is flying. Interference with such as can be suppressed. The self-excited oscillating heat pipe 6 of the third embodiment may be accommodated in the recess 24.

[Embodiment 6]
FIG. 15 is a perspective view showing the cooling device in the sixth embodiment, but is shown so that the heat receiving plate 12 is located below. As a difference from the first to fifth embodiments, in the present embodiment, the heat dissipation portion side flat tube end sealing member 9 including the third slit plate 18 is provided so as to protrude in the alignment direction of the multi-hole flat tube 8. A hydraulic fluid injection flow path 23 (see FIG. 13) that communicates between the internal communication flow path and the outside is provided, and a cap 21 with an injection tube is joined to the outer end portion thereof. Even in such a configuration, the same effect as that of the first embodiment can be obtained. Further, when the injection pipe 21a is crushed and sealed, the crushing tool (not shown) does not interfere with other components, so that workability is good.

[Embodiment 7]
FIG. 16 is a perspective view showing the cooling device in the seventh embodiment, but is shown so that the heat receiving plate 12 is located below. The difference from the first to sixth embodiments is that the pitch of the multi-hole flat tube 8 is partially narrowed or widened. Even in such a configuration in which the multi-hole flat tube 8 has an unequal pitch, the same effect as that of the first embodiment can be obtained. Further, an imbalance in the amount of heat received occurs due to the difference in the heat receiving area between the heat receiving portion in a place where the pitch is narrow and another heat receiving portion. As a result, imbalance of pressure in the flow path 13 is likely to occur, so that the startability and cooling performance of the working fluid are improved.

[Embodiment 8]
FIG. 17 is a perspective view showing the cooling device in the eighth embodiment, but is shown so that the heat receiving plate 12 is located below. The difference from the first to seventh embodiments is that the pitch (repetition cycle) of the corrugated fins 11 of the self-excited oscillating heat pipe 6 is partially widened or narrowed. Even in such a configuration in which the corrugated fins 11 have different repetition periods, the same effect as that of the first embodiment can be obtained. Further, the heat radiating portion of the corrugated fin 11 where the pitch is narrow causes an imbalance in the amount of heat radiating due to the difference in the heat radiating area from the other heat radiating portions. As a result, imbalance of pressure in the flow path 13 is likely to occur, so that the startability and cooling performance of the working fluid are improved.

[Embodiment 9]
FIG. 18 is a perspective view showing a cooling device in a state where the heat receiving plate 12 is disassembled in the ninth embodiment. As a difference from the first to eighth embodiments, in the present embodiment, a single heat receiving plate 12 provided with a rectangular concave communication flow path 25 allows the flat tube ends on the heat receiving portion side of a plurality of self-excited oscillating heat pipes 6. The part is sealed. In the present embodiment, the third slit plate is not provided, and the heat receiving plate 12 also serves as the third slit plate. Even in such a configuration, the same effect as that of the first embodiment can be obtained. In addition, since the number of parts and the number of joints are reduced as compared with the case where a plurality of slit plates are stacked, the weight can be reduced, the joint quality is stable, and the cooling performance is improved. Here, the heat receiving plate 12 may be provided with a recess for holding and aligning the multi-hole flat tube. Further, the end of the flat tube on the heat receiving portion side of the single self-excited oscillating heat pipe 6 may be sealed with a single heat receiving plate having a communication flow path groove. The communication flow path 25 may be manufactured, for example, by cutting.

[Embodiment 10]
FIG. 19 is a cross-sectional view of the power conversion device mounted on the railway vehicle as a moving body in the tenth embodiment when viewed from a direction orthogonal to the traveling direction. In the present embodiment, a plurality of semiconductor elements 3 on the heat receiving plate 12 are arranged in a plurality of rows and are electrically connected to an electric component (capacitor or the like) 27 by a bus bar 26. Here, the bus bar 26 has an L-shape having a surface 26a parallel to the heat-receiving plate 12 and a surface 26b perpendicular to the heat-receiving plate 12, and the electric component 27 is arranged in the space inside the L-shape.

By providing the L-shaped bus bar 26 in this way, the cooling device, the semiconductor element mounting surface (heat receiving surface), and the electric components can be arranged in a straight line, and since there is no dead space, a compact power conversion device can be realized. can.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration in one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. .. Further, it is also possible to add / delete / replace a part of the configuration in each embodiment with another configuration. For example, the present invention is applicable not only to railroad vehicles but also to cooling devices for moving objects such as automobiles, aircraft, and ships.

1: Power conversion device 2: Railroad vehicle 3: Semiconductor element 4: Electrical component group 5: Cooling device 6: Self-excited vibration heat pipe 7: Heat receiving part side flat pipe end sealing member 8: Multi-hole flat pipe 9: Heat dissipation Part side flat pipe end sealing member 10: Running wind 11: corrugated fin 12: heat receiving plate 13: flow path 14: partition wall 15: communication flow path 16: first slit plate
17: Second slit plate 18: Third slit plate 19: Heat receiving part side top plate 20: Heat dissipation part side top plate 21: Cap with injection pipe 22: Short multi-hole flat tube 23: Flow path for hydraulic fluid injection 24: Recess 25: Communication flow path 26: Bus bar 27: Electrical component 30: Longitudinal direction of multi-hole flat pipe 31: Short direction of multi-hole flat pipe 32: Alignment direction of multi-hole flat pipe 33: Short side of slit plate direction

Claims (20)

A plurality of multi-channel structures having a plurality of in-pipe channels filled with a working fluid, and a plurality of multi-channel structures.
A first end-side sealing member having a communication flow path that is joined to one end of the double flow path structure and connects the in-pipe flow paths of the adjacent double flow path structures.
Having a second end-side sealing member joined to the other end of the multi-channel structure and provided with a communication flow path connecting the in-pipe channels of the adjacent multi-channel structure. A self-excited vibration heat pipe featuring. In the self-excited oscillating heat pipe according to claim 1.
A self-excited oscillating heat pipe, wherein the first end-side sealing member or the second end-side sealing member is composed of an integral part. In the self-excited oscillating heat pipe according to claim 2.
A self-excited oscillating heat pipe, wherein the first end-side sealing member or the second end-side sealing member is a heat receiving plate. In the self-excited oscillating heat pipe according to any one of claims 1 to 3.
At least one of the first end-side sealing member and the second end-side sealing member has an interval holding plate for arranging and fixing the double flow path structure in parallel, and the adjacent double flow. A self-excited oscillating heat pipe characterized in that a flow path communication plate connecting a flow path in a pipe of a road structure and a top plate are overlapped with each other. In the self-excited oscillating heat pipe according to claim 4.
A self-excited oscillating heat pipe comprising the space holding plate and the flow path communication plate, or the flow path communication plate and the top plate as an integral part. In the self-excited oscillating heat pipe according to claim 4 or 5.
A self-excited oscillating heat pipe, wherein the top plate of the first end-side sealing member or the second end-side sealing member is a heat receiving plate. In the self-excited oscillating heat pipe according to any one of claims 1 to 6.
A self-excited oscillating heat pipe characterized in that corrugated fins are arranged between adjacent multi-channel structures. In the self-excited oscillating heat pipe according to any one of claims 1 to 7.
Four or more of the multi-channel structures are provided,
At least one of the first end-side sealing member and the second end-side sealing member is separate from the first communication flow path that communicates the in-pipe flow path of the two multi-flow path structures. A self-excited oscillating heat pipe having a second communication flow path that communicates the in-pipe flow path of the two double flow path structures. In the self-excited oscillating heat pipe according to any one of claims 1 to 8.
It has a short multi-channel structure having a length shorter than that of the multi-channel structure.
One end of the short multi-channel structure is joined to the first end-side sealing member or the second end-side sealing member, and the other end is provided with a working fluid injection tube. A self-excited oscillating heat pipe characterized by being sealed by a cap. In the self-excited oscillating heat pipe according to any one of claims 1 to 9.
The first end-side sealing member or the second end-side sealing member has a flow path for injecting a working liquid that communicates the in-pipe flow path and the outside of the double flow path structure. The self-excited oscillating heat pipe, characterized in that the hydraulic fluid injection flow path is sealed by a cap with a hydraulic fluid injection pipe. In the self-excited oscillating heat pipe according to claim 10.
The self-excited member is characterized in that the first end-side sealing member or the second end-side sealing member is formed long so as to protrude from the heat receiving plate in the alignment direction of the multi-channel structure. Vibration heat pipe. In the self-excited oscillating heat pipe according to claim 10 or 11.
The first end-side sealing member or the second end-side sealing member protrudes from the alignment direction end of the multi-channel structure.
A self-excited oscillating heat pipe comprising a heat receiving plate having a recess for accommodating the first end-side sealing member or the second end-side sealing member and the cap with a hydraulic fluid injection tube. In the self-excited oscillating heat pipe according to any one of claims 9 to 12.
A self-excited oscillating heat pipe characterized in that the flow path for injecting a working liquid is sealed by crushing the working liquid injection pipe provided in the cap with the working liquid injection pipe. In the self-excited oscillating heat pipe according to any one of claims 1 to 13.
A self-excited oscillating heat pipe characterized in that the alignment direction pitches of the multi-channel structure are different. In the self-excited oscillating heat pipe according to any one of claims 1 to 14.
A self-excited oscillating heat pipe characterized in that corrugated fins arranged between adjacent multichannel structures have different repetition periods. In the self-excited oscillating heat pipe according to any one of claims 1 to 15.
When n is an integer of 1 or more, the (2n-1) th compound channel structure, the (2n) th compound channel structure, and the (2n + 1) th compound channel structure are the same. It is provided in parallel in order, and the communication flow path of the first end side sealing member is one end of the (2n-1) th double flow path structure and the (2n) th double flow path structure. The communication flow path of the second end side sealing member communicates with each other, and the other end of the (2n + 1) th double flow path structure communicates with each other. A self-excited vibration heat pipe featuring. In the self-excited oscillating heat pipe according to any one of claims 1 to 15.
When m is an integer of 1 or more, the (2m-1) th in-pipe flow path in the longitudinal direction of the first end-side sealing member or the second end-side sealing member. , The (2m) th in-pipe flow path and the (2m + 1) th in-pipe flow path are provided in parallel in this order, and the communication flow path of the first end side sealing member is (2m + 1). The upper ends of the 2m-1) th in-pipe flow path and the (2m) th in-pipe flow path are communicated with each other, and the communication flow path of the second end side sealing member is in the (2 m) th in the pipe. Communicate between the flow path and the lower end of the (2m + 1) th in-pipe flow path,
Further, the upper end of the inner flow path of one of the (2 m) th in-pipe flow paths adjacent to each other in the lateral direction of the first end-side sealing member or the second end-side sealing member. Is characterized in that it communicates with the (2m-1) th in-pipe flow path, and the upper end of the other (2m) th in-pipe flow path communicates with the (2m + 1) th in-pipe flow path. Excited vibration heat pipe. A cooling device comprising the self-excited oscillating heat pipe according to any one of claims 1 to 17 and a heat receiving plate connected to a heating element. In the cooling device according to claim 18,
A cooling device characterized by being installed on a moving body. A power conversion device comprising the cooling device according to claim 19.

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