JP7513482B2 - Cooler for moving body, power conversion device for railway vehicle, cooling method for moving body, and cooling method for power conversion device for railway vehicle - Google Patents

Description

The present invention relates to a cooling device for a moving body, a power conversion device for a railway vehicle, a cooling method for a moving body, and a cooling method for a power conversion device for a railway vehicle.

A power conversion device that controls the power supplied to the traction motor is installed under the floor of the railway vehicle. The power conversion device is equipped with semiconductor elements that perform current switching to convert between DC and AC.

Semiconductor elements generate heat when current is applied and when switching occurs. If the semiconductor elements become too hot due to this heat, there is a concern that the conversion efficiency may decrease or the elements may be destroyed, so the semiconductor elements must be cooled to maintain a specified temperature range. Power conversion devices using such semiconductor elements are often mounted under the floor of a vehicle, etc., and since mounting space is limited, it is necessary to provide a more compact and efficient cooler.

As an example of a cooler attached to a power conversion circuit (vehicle semiconductor device) having a heat source such as a semiconductor element mounted under the floor of a railway vehicle, Patent Document 1 discloses a structure of a cooling device for a vehicle semiconductor device, which is provided with a baffle plate that directs the running wind above the heat dissipation fins of multiple coolers when the railway vehicle is moving. This prevents hot air that has been heat exchanged by the heat dissipation fins of the front stage cooler from flowing into the heat dissipation fins of the rear stage cooler, improving the cooling efficiency, i.e., preventing a decrease in cooling efficiency due to wind heat.

JP 2001-24124 A

In the structure of Patent Document 1, the ventilation action between the heat dissipation fins does not actively utilize the wind from the vehicle as it travels, but is limited to the action of natural convection caused by the buoyancy of the air that expands with the rise in temperature after heat exchange and becomes lighter in specific gravity. Therefore, even if the phenomenon in which the cooling efficiency decreases when the hot air that has been heat exchanged in the front heat dissipation fins flows into the rear heat dissipation fins, i.e., the damage caused by wind, is reduced, the effect of improving the cooling efficiency by utilizing the wind from the vehicle is not obtained.

The present invention is intended to solve the above-mentioned problems, and aims to provide a cooling device for a moving body that efficiently takes in the wind generated by the vehicle while it is moving, thereby improving cooling efficiency.

To solve the above problems, one representative mobile body cooler according to the present invention is a mobile body cooler that cools a heat source provided under the floor of a mobile body, and includes a heat receiving plate for the heat source, heat dissipation fins for the heat receiving plate, an air guide that covers the end faces of the heat receiving plate and the heat dissipation fins in the direction of movement of the mobile body and guides the traveling air above the heat receiving plate, side plates located on the sides of the heat receiving plate and the heat dissipation fins, and a bottom plate for the side plates, and an opening is provided between the air guide and the bottom plate to take in the traveling air.

The present invention provides a cooling device for a moving object that efficiently takes in the wind generated by the vehicle while it is moving, improving the cooling efficiency. Problems, configurations, and effects other than those described above will become clear from the description of the embodiments below.

1 is a schematic front view of a railway vehicle power conversion device according to a first embodiment of the present invention, taken along the line corresponding to the direction of movement of the railway vehicle. 2 is a perspective view showing a relationship between a heat source and a moving body cooler in the railcar power conversion device of FIG. 1 . FIG. 2 is a perspective view showing a schematic configuration of the railcar power conversion device of FIG. 1 . 2 is a schematic diagram of the railcar power converter of FIG. 1 as viewed from the sleeper direction. FIG. FIG. 6 is a perspective view showing a schematic configuration of a railway vehicle power conversion device according to a second embodiment of the present invention. 6 is a schematic diagram of the railcar power converter of FIG. 5 as viewed from the sleeper direction. FIG. 11 is a perspective view showing a relationship between a heat source and a moving body cooler using a heat pipe in a third embodiment of the present invention. FIG. 11 is a schematic diagram of a railway vehicle power conversion device according to a third embodiment of the present invention, as viewed from the sleeper direction. FIG. 11 is a perspective view showing the relationship between a heat source and a moving body cooler using a self-excited oscillating heat pipe in a fourth embodiment of the present invention. FIG. 11 is a schematic diagram of a railway vehicle power conversion device according to a fourth embodiment of the present invention, as viewed from the sleeper direction. FIG. 11 is a schematic front view of a railway vehicle power conversion device according to a fifth embodiment of the present invention, taken along the line corresponding to the direction of movement of the railway vehicle. 12 is a perspective view showing the relationship between a heat source and a moving body cooler in the railcar power conversion device of FIG. 11 . 12 is a schematic diagram of the railcar power converter of FIG. 11 viewed from the sleeper direction. FIG. FIG. 13 is a schematic front view of a railway vehicle power conversion device according to a sixth embodiment of the present invention, taken along the line corresponding to the direction of movement of the railway vehicle. 15 is a perspective view showing the relationship between a heat source and a moving body cooler in the railcar power converter of FIG. 14 . 15 is a schematic diagram of the railcar power converter of FIG. 14 viewed from the sleeper direction. FIG. 15 is a schematic diagram of the inside of the power conversion device of FIG. 14 as viewed from the sleeper direction.

Below, the embodiments of the present invention will be described with reference to the drawings. Example 1 is shown in Figs. 1 to 4, Example 2 is shown in Figs. 5 to 6, Example 3 is shown in Figs. 7 to 8, Example 4 is shown in Figs. 9 to 10, Example 5 is shown in Figs. 11 to 13, and Example 6 is shown in Figs. 14 to 17. The reference numerals of the electric power converter for rail vehicles (hereinafter also referred to as "electric power converter") are 1A in Example 1, 1B in Example 2, 1C in Example 3, 1D in Example 4, 1E in Example 5, and 1F in Example 6, but 1 is used when Examples 1 to 6 are not differentiated. The reference numerals of the cooler for a moving body (hereinafter also referred to as "cooler") are 6A in Examples 1 and 2, 6B in Example 3, 6C in Example 4, 6D in Example 5, and 6E in Example 6, but 6 is used when Examples 1 to 6 are not differentiated.

The coordinate axes are shown in the drawing, with the running (moving) direction X being the direction in which the rails are installed and indicating the direction in which the railway vehicle (moving body) 2 moves, the sleeper direction Y being the direction in which the sleepers connecting the rails are installed, and the height direction Z indicating the vertical upward direction. Furthermore, the power conversion device 1 refers to a combination of a power conversion circuit with a cooler. The power conversion circuit is primarily an inverter or converter that has a heat source 3 such as a semiconductor switching element, and includes a control board but does not include a cooler. The cooler refers to a functional part whose sole purpose is cooling.

Figure 1 is a schematic front view of a power conversion device 1A according to a first embodiment of the present invention, taken along the direction of movement of a railway vehicle 2. The power conversion device 1A is installed under the floor of the railway vehicle 2, and controls the rotation speed of an electric motor (not shown) that drives the railway vehicle 2 by changing the frequency of the power supplied to the electric motor.

Inside the power conversion device 1A, there are installed multiple semiconductor elements (heat sources) 3 that make up the power conversion circuit, a capacitor 4, a control board 5, etc., as well as electrical components necessary for controlling the flow of current to the semiconductor elements 3. The semiconductor elements 3 generate heat loss when current is applied and when they are switched ON/OFF, and this heat loss is dissipated into the outside air, becoming the heat source 3 (same symbol).

The cooler 6A is placed on the side of the power conversion device 1A. The cooler 6A is supplied with the wind 9 generated when the railcar 2 moves in a direction perpendicular to the plane of the paper in FIG. 1, and dissipates the heat loss generated by the semiconductor element 3. The railcar 2 moves in both forward and backward directions, so the wind 9 generated is determined by the direction of movement.

The power conversion device 1A and the cooler 6A are also installed in a position where they do not interfere with surrounding structures beside the tracks while the railway vehicle 2 carrying them is in motion. In other words, the power conversion device 1A and the cooler 6A are installed within an area that fits inside the side of the railway vehicle 2 in the direction of the sleepers. For this reason, the cooler 6A is placed under the car body floor surface 10 of the railway vehicle 2.

Figure 2 is a perspective view showing the relationship between the heat source 3 and the mobile cooler 6A in the power conversion device 1A of Figure 1. The cooler 6A is composed of a heat receiving plate 7 and heat dissipation fins 8. The heat receiving plate 7 is installed in the power conversion device 1A so that, as an example, it maintains an upright position in the vertical direction with multiple semiconductor elements 3 attached to the same surface.

The semiconductor element 3 is, for example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The heat dissipation fins 8 are installed to facilitate ventilation in the vertical direction, and by supplying air between the heat dissipation fins 8, the heat loss generated by the semiconductor element 3 is dissipated into the air.

Figure 3 is a perspective view showing the schematic configuration of the power conversion device 1A of Figure 1. In Figure 3, the railway vehicle 2 located above the power conversion device 1A is not shown. At the front and rear stages of the cooler 6A in the running direction, air guide slopes (hereinafter also referred to as "air guide bodies") 11 are installed in an area covering the projection surface of the cooler 6A as seen from the running direction. The front and rear air guide slopes 11 are symmetrical in shape.

A side plate 13 is disposed on the sleeper side of the cooler 6A, and a bottom plate 12 is installed below the cooler 6A. The side plate 13 is large enough to cover a larger area than the cooler 6A and the air guide slope 11. In this way, the cooler 6A is covered by the air guide slope 11, side plate 13, and bottom plate 12, and is disposed in a position that is not directly visible from the running direction, sleeper direction, or underneath. An opening 14 is provided in the space surrounded by the underside of the air guide slope 11, the bottom plate 12, and the side plate 13 to take in the running wind 9.

Figure 4 is a schematic diagram of the power conversion device 1A of Figure 1, seen from the sleeper direction. In Figure 4, the side panels 13 are not shown. The heat dissipation fins 8 are formed into a compact assembly that ensures a large surface area for the high-temperature parts exposed to air, in order to enhance the air-cooling effect of dissipating heat through ventilation. The outer shape of the assembly is roughly a rectangular parallelepiped, and in the normal usage position, it has vertical and horizontal surfaces. All four vertical faces of the rectangular parallelepiped are blocked from ventilation.

The wind guide slope 11 is installed in an area that covers the projection surface of the rectangular parallelepiped in both the front and rear directions of the rectangular parallelepiped based on the direction of movement of the moving body 2. The side plates 13 cover the sides of the rectangular parallelepiped based on the running (movement) direction. The bottom plate 12 is installed parallel to and spaced apart from the bottom surface of the rectangular parallelepiped to ensure a specified gap.

The air guide slope 11 extends from a base end connected to each of the front and rear sides that form the top surface of the rectangular parallelepiped toward the end of the terminal point. When the air guide slope 11 is viewed from the side with respect to the direction of movement of the moving body 2 as a reference, it slopes downward as it moves away from the center of the rectangular parallelepiped. In other words, in the cooler 6A, the air guide slope 11 is configured so that the vertical cross-sectional area of the upper space formed between the lower side of the floor surface 10 and the slope increases as it moves away from the rectangular parallelepiped in the front-rear direction.

In other words, the wind guide slope 11 is installed at an angle so that when the center of the rectangular parallelepiped is viewed from either the front or rear of the cooler 6A, with the driving (movement) direction as the reference, the cross-sectional area of the upper space 15 between the underside of the vehicle body floor surface 10 and the cooler 6A gradually decreases. As a result, the driving wind 9 supplied to the upper part of the wind guide slope 11 is accelerated as it approaches the upper space 15.

The running wind 9 is supplied from the opening 14 to the lower space 16 of the cooler 6A, part of it is supplied between the heat dissipation fins 8, and part of it is discharged to the outside from the opening 14 on the rear side. The top surface of the mountain-shaped wind guide slope 11 and the top surface of the cooler 6A are positioned at approximately the same height.

The effects of Example 1 will be explained. The cooler 6A is covered by the air guide slope 11, the side plate 13, and the bottom plate 12. The cooler 6A is also placed in a position that is not directly visible in the running direction, in the sleeper direction, or from the bottom. Therefore, the cooler 6A is not directly hit by flying objects such as ballast stones installed around the rail. Therefore, damage to the cooler 6A can be suppressed, and reliability is improved.

The ventilation passage formed between the upper surface of the wind guide slope 11 and the underside of the vehicle body floor surface 10 is configured to be constricted in the upper space 15 of the cooler 6A. The static pressure in the upper space 15 decreases as the traveling wind 9 accelerates at the constricted portion of the ventilation passage, i.e., in the upper space 15 of the cooler 6A. This action creates a pressure difference between the upper space 15 and the lower space 16 of the cooler 6A, and the traveling wind 9 taken in from the opening 14 on the lower side of the wind guide slope 11 into the lower space 16 of the cooler 6A generates an ascending air current 17 that passes between the heat dissipation fins 8 of the cooler 6A and is sucked up into the upper space 15. At this time, the air is ventilated only from the bottom surface of the rectangular parallelepiped to the top surface.

This allows the running wind 9 to be efficiently supplied between the heat dissipation fins 8, improving cooling efficiency. Also, by installing a mountain-shaped wind guide slope 11 symmetrical to the front section when viewed from the sleeper direction as shown in Figure 4 at the rear section of the cooler 6A, the effect of generating an updraft 17 can be obtained in the same way even when the railway vehicle 2 is traveling in the opposite direction, so that the running wind can be efficiently supplied between the heat dissipation fins 8 regardless of the traveling direction, and a cooler with good cooling efficiency can be provided.

In addition, the side panels 13 are large enough to cover a wider area than the cooler 6A and the air guide slope 11, preventing the traveling wind 9 taken in through the opening 14 and the traveling wind 9 taken in from the top of the air guide slope 11 from flowing out in the direction of the sleepers. If the traveling wind 9 flowed out in the direction of the sleepers, it would be difficult to create a pressure difference between the upper space 15 and the lower space 16, and the traveling wind 9 would not be efficiently supplied between the heat dissipation fins 8. Therefore, the installation of the side panels 13 improves cooling efficiency.

In addition, if the accelerated running wind 9 at the top of the air guide slope 11 separates, it becomes difficult to create a pressure difference between the upper space 15 and the lower space 16, and the running wind 9 is not efficiently supplied between the heat dissipation fins 8. By arranging the upper surface of the air guide slope 11 and the upper surface of the cooler 6A at approximately the same height, it is possible to prevent the accelerated running wind 9 at the top of the air guide slope 11 from separating.

Figure 5 is a perspective view showing the schematic configuration of a power conversion device 1B according to a second embodiment of the present invention. Also, Figure 6 is a schematic view of the power conversion device 1B of Figure 5 as seen from the sleeper direction. A ceiling plate 18 is installed in the upper space 15 of the car body floor surface 10 and the cooler 6A to further reduce the cross-sectional area of the upper space 15 compared to the first embodiment.

In some cases, the cross-sectional area of the upper space 15 cannot be made very small due to the balance between the arrangement of the power conversion device 1B and the surrounding components of the vehicle floor surface 10. In such cases, the cross-sectional area of the upper space 15 can be further reduced by using the ceiling plate 18, thereby ensuring the pressure difference between the upper space 15 and the lower space 16, as in Example 1. As a result, the power conversion device 1B can improve cooling efficiency by efficiently supplying the running wind 9 between the heat dissipation fins 8 that make up the cooler 6A.

Figure 7 is a perspective view showing the relationship between a heat source 3 and a cooler 6B using a heat pipe in the third embodiment of the present invention. Also, Figure 8 is a schematic diagram of a power conversion device 1C according to the third embodiment of the present invention, viewed from the sleeper direction.

The cooler 6B of the third embodiment has multiple heat pipes 19 for transferring heat from the heat receiving plate 7 to the heat dissipation fins 8. Heat pipes generally have a copper tube filled with pure water, ethanol, methanol, or the like as a working fluid. This improves the cooling efficiency without impeding the supply of the running wind 9 between the heat dissipation fins 8.

Figure 9 is a perspective view showing the relationship between a cooler 6C using a self-excited oscillating heat pipe 20 and a heat source 3 in the fourth embodiment of the present invention. Also, Figure 10 is a schematic diagram of a power conversion device 1D according to the fourth embodiment of the present invention, viewed from the sleeper direction.

The cooler 6C of Example 4 has multiple self-excited oscillating heat pipes 20 instead of heat dissipation fins 8. The self-excited oscillating heat pipes 20 are composed of a porous flat tube held by a first connecting plate 21 on the heat receiving plate 7 side and a second connecting plate 22 on the opposite side. This self-excited oscillating heat pipe 20 has a serpentine flow path (not shown) inside that alternates between the first connecting plate 21 and the second connecting plate 22, i.e., the heat receiving side where the temperature increases and the heat dissipation side through which cooling air passes.

Alternatively, a connecting flow path (not shown) that connects the flow paths in adjacent self-excited oscillating heat pipes 20 may be provided on the first connecting plate 21 and the second connecting plate 22, so that the flow path connecting multiple self-excited oscillating heat pipes 20 alternates between the heat receiving side, where the temperature is high, and the heat dissipating side, where cooling air passes through.

A predetermined amount of working fluid (not shown) is sealed in the flow path. Examples of working fluids that can be used include water, alcohols, hydrocarbons such as butane, hydrofluorocarbons, hydrofluoroethers, hydrofluoroolefins, and perfluoroketones.

The effect of Example 4 will be explained. In the case of the heat pipe 19 as in Example 3, the working fluid needs to be returned to the heat receiving plate 7 side by gravity, so the heat pipe 19 needs to be installed at an angle in the vertical direction, which creates dead space.

On the other hand, the self-excited oscillating heat pipe 20 circulates the working fluid to the heat receiving plate 7 side due to the pressure difference caused by the boiling of the working fluid inside. Therefore, the self-excited oscillating heat pipe 20 does not need to be installed at an angle in the vertical direction like the heat pipe 19.

This allows the installation space for the cooler 6 to be reduced. In addition, heat dissipation fins 8 may be installed between the self-excited oscillating heat pipes 20, which increases the heat dissipation area and improves cooling efficiency.

The cooler 6C of Example 4 and the cooler 6E of Example 6 described below are both configured with multiple self-excited oscillating heat pipes 20 made of porous flat tubes instead of heat dissipation fins 8. The self-excited oscillating heat pipes 20 have an external shape like a folded ribbon made of porous flat tubes, so they can be considered as ribbon-shaped heat dissipation fins.

Figure 11 is a schematic front view of a power conversion device 1E according to a fifth embodiment of the present invention, based on the direction of travel of a railway vehicle. Figure 12 is a perspective view showing the relationship between the heat source 3 and the moving body cooler in the power conversion device 1E of Figure 11.

Figure 13 is a schematic diagram of the power conversion device 1E of Figure 11 as viewed from the sleeper direction. In Figure 11, the capacitor 4 and control board 5 installed in the power conversion device 1E are not shown. In the power conversion device 1E of Example 5, the heat receiving plate 7 is installed horizontally, and multiple semiconductor elements 3 are installed on the same surface of the heat receiving plate 7.

In the power conversion device 1E of the fifth embodiment, one side of the heat pipe 19 is embedded in the heat receiving plate 7, and the other side is installed so as to protrude from the side of the power conversion device 1E, and multiple heat dissipation fins 8 are installed on the protruding part. Also, as shown in FIG. 11, the protruding part of the heat pipe 19 is installed at an angle in the height direction.

In this way, by installing the heat receiving plate 7 horizontally, the installation space in the height direction of the cooler 6D can be reduced, and the power conversion device 1E can be made smaller. In addition, by embedding the heat pipe 19 in the heat receiving plate 7, it is possible to achieve both improved cooling efficiency and compactness.

In this embodiment, multiple semiconductor elements 3 are installed on the same surface of the heat receiving plate 7, but a configuration (not shown) in which semiconductor elements 3 are attached to two opposing surfaces of the heat receiving plate 7 can also be used, thereby reducing the installation space in the direction of the sleepers of the cooler 6 and making the power conversion device 1E smaller.

Figure 14 is a schematic front view of a power conversion device 1F according to a sixth embodiment of the present invention, based on the direction of movement of a railway vehicle. Figure 15 is a perspective view showing the relationship between the heat source 3 and the moving body cooler in the power conversion device 1F of Figure 14.

Figure 16 is a schematic diagram of the power conversion device 1F in Figure 14 as seen from the sleeper direction. It is a schematic diagram of the power conversion device 1F and the cooler in Example 6 as seen from the sleeper direction. In Figure 14, the capacitor 4 and the control board 5 installed in the power conversion device 1F are not shown.

The heat receiving plate 7 is installed horizontally, and multiple semiconductor elements 3 are installed on the same surface of the heat receiving plate 7. One side of the self-excited oscillating heat pipe 20 is embedded in the heat receiving plate 7, and the other side is installed so as to protrude from the side of the power conversion device 1F, and both ends are held by the first connecting plate 21 and the second connecting plate 22.

The self-excited oscillating heat pipe 20 has a serpentine flow path (not shown) between the first connecting plate 21 and the second connecting plate 22, that is, between the heat receiving side where the temperature is high and the heat releasing side through which the cooling air passes. The self-excited oscillating heat pipe 20 does not need to have a single serpentine flow path, and may have multiple serpentine flow paths connected in parallel or series.

In other words, the flow path connecting multiple self-excited oscillating heat pipes 20 may be configured to alternate between the heat receiving side where the temperature is high and the heat dissipation side through which cooling air passes. To achieve this, it is recommended to provide a connecting flow path (not shown) on each of the first connecting plate 21 and the second connecting plate 22 that folds back and connects the flow paths in the adjacent self-excited oscillating heat pipes 20 to form a serpentine flow path.

A predetermined amount of working fluid (not shown) is sealed in the flow path. As the working fluid, for example, at least one of water, alcohols, hydrocarbons such as butane, hydrofluorocarbons, hydrofluoroethers, hydrofluoroolefins, perfluoroketones, etc. is suitable.

The effect of Example 6 will be explained. As in Example 4, the self-excited oscillating heat pipe 20 does not require a steep gradient between the base end and the end end as in the heat pipe 19, so there is a high degree of freedom in the connection system and the installation space for the cooler 6E can be reduced. In addition, heat dissipation fins 8 may be installed between the self-excited oscillating heat pipes 20, and installing the heat dissipation fins 8 increases the heat dissipation area and improves the cooling efficiency.

Also, FIG. 17 is a schematic diagram of the inside of the power conversion device 1F in FIG. 14, viewed from the sleeper direction. The capacitor 4 and control board 5 are installed on both sides of the semiconductor element 3 in the running direction. With this configuration, the power conversion device 1F can reduce the installation space for the capacitor 4 and control board 5 in the height direction and sleeper direction. As a result, the power conversion device 1F can be made smaller.

In addition, the power conversion device 1F can be made smaller by simplifying the shapes of the main circuit wires 23 that connect the semiconductor elements 3 and the capacitors 4, and the control wires 24 that connect the semiconductor elements 3 and the control board 5. As a result, the inductance of the wiring can also be reduced.

The cooling device for a moving body (hereinafter, also referred to as "the cooling device") 6 according to the embodiment of the present invention can be summarized as follows.
[1] A moving body cooler 6 for cooling a heat source 3 provided under the floor of a moving body 2, comprising a heat receiving plate 7 for the heat source 3, a heat dissipation fin 8 thermally connected to the heat receiving plate 7, an air guide 11 covering the end faces of the heat receiving plate 7 and the heat dissipation fin 8 in the moving direction of the moving body 2 and guiding the traveling wind above the heat receiving plate 7, a side plate 13 positioned on the side of the heat receiving plate 7 and the heat dissipation fin 8, and a bottom plate 12 for the side plate 13, and an opening 14 for taking in the traveling wind is provided between the air guide 11 and the bottom plate 12. The cooler 6 configured in this way can efficiently take in the traveling wind to increase cooling efficiency.

[2] This cooler 6A is a cooler 6A for a moving body that cools a heat source 3 provided under the floor of a moving body 2 having a floor surface 10, and includes a heat receiving plate 7, heat dissipation fins 8, an air guide slope (air guide) 11, a side plate 13, and a bottom plate 12. The heat receiving plate 7 has a plurality of semiconductor elements 3 arranged thereon that serve as heat sources 3, and the temperature of the heat receiving plate 7 rises due to thermal conduction from the heat sources 3. The heat dissipation fins 8 also rise in temperature due to thermal conduction from the heat receiving plate 7, but by ventilating the high-temperature portion and dissipating the heat, they remove the heat from the heat source 3 and cool it.

The heat dissipation fins 8 are formed into a compact assembly that ensures a large surface area for the high-temperature parts exposed to air, in order to improve the air-cooling effect of dissipating heat through ventilation. The outer shape of the assembly is roughly a rectangular parallelepiped, and when in normal use, it has vertical and horizontal surfaces.

The heat dissipation fins 8 of this cooler 6A provide an efficient air-cooling effect by smoothly and continuously ventilating fresh, cool air only from the bottom surface of the rectangular parallelepiped to the top surface. Conversely, factors that impede the air-cooling effect include, first, the heat blown out from other coolers installed in series, and, second, a decrease in the air flow speed. This cooler 6A eliminates these impeding factors.

The air guide 11 is installed in an area that covers the projection surface of the rectangular parallelepiped in both the front and rear directions of the rectangular parallelepiped based on the direction of movement of the moving body 2. The side plates 13 cover the sides of the rectangular parallelepiped based on the direction of movement. The bottom plate 12 is installed parallel to and spaced apart from the bottom surface of the rectangular parallelepiped.

As shown in Figures 3 to 6, 8, 10, 13, and 16, the cooler 6 has an opening 14 for taking in the running wind 9 in the lower space of the rectangular parallelepiped. This opening 14 is provided in a position surrounded by the lower side of the air guide 11, the bottom plate 12, and the side plate 13.

The air guide 11 extends from its base end connected to both the front and rear sides that form the top surface of the rectangular parallelepiped toward its end point. When the air guide 11 is viewed from the side with respect to the direction of movement of the moving body 2, it slopes downward as it moves away from the center of the rectangular parallelepiped.

In other words, in this cooler 6A, the air guide 11 is configured so that the vertical cross-sectional area of the upper space formed between the air guide 11 and the underside of the floor surface 10 increases as it moves away from the rectangular parallelepiped in the front-to-rear direction. Moreover, by arranging the upper surface of the air guide 11 and the upper surface of the cooler 6A at approximately the same height, it is possible to prevent the accelerated running wind 9 from separating from the upper part of the air guide 11.

As shown in Figures 4, 6, 8, 10, 13, and 16, in this cooler 6A, the upper space formed between the upper side of the air guide 11 and the lower side of the floor surface 10 can take in a large amount of cooling air due to the running wind 9, regardless of whether the moving body 2 is moving forward or backward.

The cooling air that is taken in increases its speed in the space above the top surface of the funnel-shaped rectangular parallelepiped, lowering the air pressure locally. In other words, this cooler 6A applies the principle of Bernoulli's theorem, which states that as the speed of a fluid increases, its pressure decreases.

On the other hand, the wind 9 taken into the lower space of the rectangular parallelepiped is expected to be fresh and cool air, with less of an effect from the wind heat mentioned above, because the opening 14 is located low. Therefore, the wind heat, which was the first impediment to the air cooling effect, is eliminated.

This cool air is sucked in from the bottom of the rectangular parallelepiped, and rises as hot air while cooling the high-temperature heat dissipation fins 8. At this time, the hot air is efficiently sucked out from the top surface of the rectangular parallelepiped due to the locally reduced air pressure as described above. As a result, the second impediment to the air cooling effect, the reduction in ventilation speed, is also eliminated.

The present cooler 6A also has the effect of resolving the following concerns. For example, if a cooling device for vehicle semiconductor devices having a structure like that of Patent Document 1 is installed under the floor of a railway vehicle, there is a concern that flying objects such as ballast around the tracks will collide with and damage the cooler, resulting in a significant deterioration in cooling efficiency.

Specifically, if a flying object collides with the heat dissipation fins of a cooler and deforms them, the supply of cooling air between the fins is hindered, and cooling efficiency deteriorates. Furthermore, if the cooler is equipped with a heat pipe filled with working fluid as its heat transfer means, if a flying object collides with the heat pipe and breaks it, the working fluid inside will leak out, significantly worsening cooling efficiency.

In response to this, the cooler 6A has a protective effect provided by the side panels 13 that cover the sides and the bottom panel 12 that covers the lower space 16, eliminating the concern that flying objects will collide with and damage the cooler 6A, thereby reducing cooling efficiency. In this way, the cooler 6A can improve reliability and cooling efficiency by efficiently taking in the wind generated by traveling without allowing flying objects to collide with the cooler.

As described above, this cooler 6 is configured so that in the upper space formed between the top surface of the rectangular parallelepiped and the underside of the floor surface 10, the cross-sectional area of the vertical direction, i.e., the horizontal ventilation passage, increases with increasing distance from the rectangular parallelepiped in the front-to-rear direction.

[3] In the present cooler 6A having such a configuration, it is advisable to install a ceiling panel 18 to reduce the cross-sectional area in the vertical direction. In this way, by further narrowing the cross-sectional area of the horizontal ventilation passage, the wind speed can be further increased in the space above the top surface of the funnel-shaped rectangular parallelepiped, thereby increasing the efficiency with which hot air is drawn out from the top surface of the rectangular parallelepiped.

The ceiling plate 18 covering the upper space 15 of the present cooler 6A also has a certain degree of defensive effect against flying objects. The reason for "a certain degree of defensive effect" is that it is proportional to the relatively low probability of flying objects hitting the ceiling plate 18, rather than the degree of defensive effect of the side plates 13 covering the sides and the bottom plate 12 covering the lower space 16 of the present cooler 6A. This can therefore further reduce the concern that flying objects will collide with the present cooler 6A, damaging it and worsening the cooling efficiency.

[4] The cooler 6B preferably includes a heat pipe 19 filled with a working fluid. The heat pipe 19 increases the efficiency of heat conduction from the heat receiving plate 7 to the heat dissipation fins 8, which naturally increases the cooling efficiency.
[5] Furthermore, it is preferable that the heat pipe of this cooler 6C is a self-excited oscillating heat pipe 20 having a serpentine flow path that alternately approaches the heat receiving plate 7 and the heat dissipation fins 8, as shown in Figures 9, 10, 15, and 16.

Such a self-excited oscillating heat pipe 20 can function as a heat transfer medium with high efficiency even in a gas-liquid mixed state in which the ratio of the working fluid enclosed is increased to, for example, about 50% in a serpentine flow path set at a low gradient of, for example, 10 degrees as shown in FIG. 11.

This cooler 6 has a short, serpentine flow path with a low gradient and a high ratio of hydraulic fluid enclosed in it, which increases the cooling efficiency. As a result, it is possible to provide a compact, highly efficient cooler with a high degree of design freedom.

[6] In addition, in the present cooler 6D, as shown in Figs. 1 and 2, it is preferable that a plurality of semiconductor elements 3 are arranged on the same surface of the heat receiving plate 7 fixed vertically.
[7] In addition, as shown in Figures 11, 12 and 14, the present cooler 6E may have a plurality of semiconductor elements 3 arranged on the same surface or two horizontally opposing surfaces (not shown) of a horizontally fixed heat receiving plate 7. The present coolers 6B and 6C are more compact and efficient than the present cooler 6A.

[8] Furthermore, the present cooler 6 described above in [1] to [7] is preferably used in the power conversion device 1. In this case, the present cooler 6 is combined with a power conversion circuit, which means an inverter or converter, to form the power conversion device 1. In other words, the present cooler 6 is suitable for cooling the heat source 3 of the power conversion circuit installed under the floor of the railway vehicle 2.

The present invention is not limited to the above-described embodiment, but includes various modifications. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to having all of the configurations described.

It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and furthermore, it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, remove, or replace part of the configuration of each embodiment with another configuration. For example, the present invention is applicable not only to railroad vehicles, but also to cooling devices for moving bodies such as automobiles, aircraft, and ships.

1, 1A to 1F Railway vehicle power converter (power converter), 2 Railway vehicle (moving body), 3 Semiconductor element (heat source), 4 Capacitor, 5 Control board, 6, 6A to 6E Moving body cooler (cooler), 7 Heat receiving plate, 8 Heat dissipation fin, 9 Running wind, 10 Car body floor, 11 Wind guide slope (wind guide), 12 Bottom plate, 13 Side plate, Opening, 15 Upper space of cooler, 16 Lower space of cooler, 17 Upward air flow passing between fins, 18 Ceiling plate, 19 Heat pipe, 20 Self-excited oscillating heat pipe, 21 First connecting plate, 22 Second connecting plate, 23 Main circuit wire, 24 Control wire, X Running (moving) direction, Y Sleeper direction, Z Height direction

Claims (16)

A cooling device for a moving body that cools a heat source provided under a floor of a moving body, comprising:
A heat receiving plate for the heat source;
A heat dissipation fin of the heat receiving plate;
a wind guide that covers the end faces of the heat receiving plate and the heat dissipation fins in the moving direction of the moving body and guides the traveling wind above the heat receiving plate;
a side plate located on a side surface of the heat receiving plate and the heat dissipating fin;
A bottom plate for the side plate;
Equipped with
An opening is provided between the air guide body and the bottom plate to take in the running wind.
Cooler for mobile objects. The heat dissipation fin has a heat receiving plate on which the semiconductor elements serving as the heat source are arranged, and an outer shape of the assembly to which heat is transferred from the heat receiving plate is a rectangular parallelepiped having vertical and horizontal surfaces, and dissipates heat by passing air from the bottom surface of the rectangular parallelepiped to the top surface,
The air guide body is installed in a range covering a virtual projection surface of the rectangular parallelepiped in each of the front and rear directions of the rectangular parallelepiped based on the moving direction of the moving body,
the side plate covers a side surface of the rectangular parallelepiped with respect to the moving direction;
The bottom plate is disposed parallel to and spaced apart from the bottom surface of the rectangular parallelepiped,
The opening is provided at a position surrounded by the lower side of the air guide body, the bottom plate, and the side plate so as to take in the running wind into the lower space of the rectangular parallelepiped,
The air guide is connected to the front and rear sides that form the top surface of the rectangular parallelepiped, and the vertical cross-sectional area of the upper space formed between the air guide and the underside of the floor surface increases as the air guide moves away from the rectangular parallelepiped in the front-rear direction.
The cooling device for a moving body according to claim 1. A ceiling plate is installed in the upper space formed between the lower side of the floor surface and the upper space to reduce the cross-sectional area.
The cooling device for a moving body according to claim 2. Equipped with a heat pipe with a working fluid sealed inside,
4. The cooling device for a moving body according to claim 2 or 3. The heat pipe is a self-excited oscillating heat pipe,
A meandering flow path is provided which alternately approaches the heat receiving plate and the heat dissipating fins,
The cooling device for a moving body according to claim 4. A plurality of the semiconductor elements are arranged on the same surface of the heat receiving plate fixed vertically.
The cooling device for a moving body according to claim 2. A plurality of the semiconductor elements are arranged on the same surface or two opposing surfaces of the heat receiving plate fixed horizontally.
The cooling device for a moving body according to claim 2. The moving body is a railway vehicle, and in order to cool the heat source of a power conversion circuit installed under a floor of the railway vehicle,
A cooling device for a moving body according to any one of claims 1 to 7,
Power conversion equipment for railway vehicles. A method for cooling a heat source provided under a floor of a moving body, comprising the steps of:
A heat receiving plate receives heat from the heat source,
An air guide body covers the end faces of the heat receiving plate and the heat dissipation fins in the moving direction of the moving body and guides the traveling air by an air guide body disposed above the heat receiving plate;
The heat receiving plate and the heat dissipation fin are surrounded by a side plate located on a side of the side plate and a bottom plate facing the side plate, and the airflow is taken in through an opening provided between the air guide and the bottom plate.
Cooling method for mobile objects. The heat dissipation fin assembly has an outer shape of a rectangular parallelepiped having vertical and horizontal surfaces;
The air guide body is installed in a range covering a virtual projection surface of the rectangular parallelepiped in each of the front and rear directions of the rectangular parallelepiped based on the moving direction of the moving body;
The side plate covers a side surface of the rectangular parallelepiped based on the moving direction;
The bottom plate is disposed parallel to and spaced apart from the bottom surface of the rectangular parallelepiped;
Using
The air guide is connected to the front and rear sides that form the top surface of the rectangular parallelepiped, and extends in a funnel shape such that the vertical cross-sectional area of the upper space formed between the air guide and the underside of the floor surface increases as it moves away from the rectangular parallelepiped in the front-rear direction,
The static pressure of the traveling wind caused by the movement of the moving body is reduced when passing through the top surface of the funnel-shaped rectangular parallelepiped in the upper space formed between the upper side of the air guide body and the lower side of the underfloor,
The running wind is taken in through an opening provided in a lower space of the rectangular parallelepiped at a position surrounded by a lower side of the air guide body, the bottom plate, and the side plate,
The traveling wind is caused to rise from the bottom surface of the rectangular parallelepiped toward the top surface.
The cooling method for a moving body according to claim 9. The cross-sectional area formed in the upper space is reduced by inserting a ceiling plate between the underside of the floor surface and the ceiling plate.
The cooling method for a moving body according to claim 10. Using a heat pipe with a working fluid sealed inside,
12. A method for cooling a moving body according to claim 10 or 11. The heat pipe may be
A self-excited oscillating heat pipe having a meandering flow path that alternately approaches the heat receiving plate and the heat dissipating fin,
The cooling method for a moving body according to claim 12. A heat receiving plate having a plurality of semiconductor elements arranged on the same surface fixed vertically is used.
The cooling method for a moving body according to claim 10. A heat receiving plate having a plurality of semiconductor elements arranged on the same surface or two opposing surfaces fixed horizontally is used.
The cooling method for a moving body according to claim 10. The moving body is a railway vehicle, and in order to cool the heat source of a power conversion circuit installed under a floor of the railway vehicle,
Using the moving body cooling method according to any one of claims 9 to 15,
A method for cooling a power conversion device for a railway vehicle.

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