WO2022195719A1

WO2022195719A1 - Boiling-type cooler

Info

Publication number: WO2022195719A1
Application number: PCT/JP2021/010598
Authority: WO
Inventors: 章裕田辺; 賢二安東
Original assignee: 住友精密工業株式会社
Priority date: 2021-03-16
Filing date: 2021-03-16
Publication date: 2022-09-22
Also published as: JPWO2022195719A1

Abstract

This boiling-type cooler (100) comprises: a boiling unit (10) that has a storage space (11) for storing a refrigerant (1), said boiling unit (10) boiling the refrigerant by exchanging heat with a heating element (HS); and a condensing unit (20) that communicates with the boiling unit and condenses refrigerant gas (1a) from the boiling unit by exchanging heat with an external fluid (2). The boiling unit: is formed in a plate shape having an upper surface (12) and a lower surface (13), each having a heating element installed thereon; and is provided so as to extend diagonally downward from a portion (30) connecting to the condensing unit.

Description

boiling cooler

The present invention relates to an ebullient cooler, and more particularly to an ebullient cooler that circulates the refrigerant between a boiling section that boils the refrigerant and a condensing section that condenses the vaporized refrigerant.

Conventionally, a boiling cooler that circulates a refrigerant between a boiling section and a condensing section is known. Such a boiling type cooler is disclosed, for example, in Japanese Patent Application Laid-Open No. 2002-134670.

The above Japanese Patent Application Laid-Open No. 2002-134670 has a structure in which a condensing section composed of a plate-fin heat exchanger is joined in an inverted T shape to the upper surface of a horizontally arranged evaporating section (boiling section). Refrigerant is sealed inside the evaporator. A plate for mounting a semiconductor element is provided on the lower surface of the evaporating section.

JP-A-2002-134670

In this specification, an ebullient cooler in which the boiling portion extends in the lateral direction, such as the ebullient cooler disclosed in JP-A-2002-134670, is referred to as a "horizontal" ebullition cooler. In a horizontal boiling type cooler, it is necessary to install a heating element on the bottom surface of the boiling section. This is because the liquid-phase refrigerant collects in the lower part of the boiling section and the vapor-phase refrigerant gas collects in the upper part, so it is difficult to obtain sufficient cooling performance even if a heating element is installed on the upper surface of the boiling section. . Therefore, in the horizontal boiling type cooler, there is a problem that it is difficult to secure an installation area for the heating element.

The present invention has been made to solve the above problems, and one object of the present invention is to make it possible to increase the installation area of a heating element even in a horizontal boiling type cooler. To provide an efficient boiling type cooler.

In order to achieve the above object, a boiling type cooler according to the present invention has a housing space for housing a refrigerant, a boiling section for boiling the refrigerant by heat exchange with a heating element, and a boiling section for communicating with the boiling section to boil the refrigerant. a condensing section for condensing the refrigerant gas from the section by heat exchange with an external fluid, wherein the boiling section is formed in a plate-like shape having an upper surface and a lower surface on which a heating element is installed, and is connected to the condensing section. It is provided so as to extend obliquely downward from the portion.

In the boiling type cooler according to the present invention, as described above, the boiling section is provided so as to extend obliquely downward from the connecting portion with the condensing section. It can be inclined with respect to the plane so that the internal top surface of the containment space is in continuous contact with the liquid coolant. Since the accommodation space slopes upward toward the condensation section, the refrigerant gas vaporized inside the accommodation space moves toward the condensation section along the inclined accommodation space. Therefore, it is possible to prevent the refrigerant gas from staying excessively on the inner upper surface of the accommodation space. As a result, the heating element installed on the upper surface of the boiling section can exhibit sufficient cooling performance. Even with a type cooler, the installation area of the heating element can be increased. In this specification, the term "horizontal boiling cooler" includes the case where the boiling section is inclined from the horizontal direction as long as the horizontal dimension is larger than the vertical dimension of the boiling section. In other words, when the boiling section has a simple flat plate shape, if the boiling section is provided at an angle of inclination of less than 45 degrees with respect to the horizontal direction, it is included in the "horizontal type" boiling type cooler.

In the above invention, preferably, the boiling portion is inclined so that the liquid level of the coolant is positioned within or above the area where the heating element is installed on the upper surface. According to this configuration, of the inner upper surface of the housing space, the area facing the installation area of the heat generating element (the area immediately below the heat generating element) can be brought into contact with the liquid refrigerant. Therefore, it is possible to prevent the region directly under the heating element from being partially dry-out, so that it is possible to effectively prevent the occurrence of local temperature rise (local decrease in cooling performance). Dryout is a state in which the liquid-phase refrigerant disappears from the heat transfer surface and the heat transfer surface is covered with gas-phase refrigerant (single-phase vapor state). rate drops significantly.

In the above invention, preferably, the boiling portion is inclined at an inclination angle of 5 degrees or more and less than 45 degrees with respect to the horizontal direction. With this configuration, the heating element can be installed on the upper surface of the boiling section while obtaining the merit of the horizontal boiling type cooler that the height dimension of the boiling type cooler can be suppressed. A horizontal boiling type cooler with an enlarged area is obtained.

In the above invention, the boiling section preferably further includes a partition plate that divides the accommodation space into an upper space adjacent to the upper surface and a lower space adjacent to the lower surface. With this configuration, the partition plate can prevent the refrigerant gas generated in the lower space of the accommodation space from moving to the upper space due to heat absorption from the heating element installed on the lower surface of the boiling section. Therefore, it is possible to prevent all the refrigerant gas from gathering on the inner upper surface of the housing space (upper space) and prevent contact between the refrigerant and the inner upper surface. can. In addition, in a heat exchanger, a state in which a liquid phase and a gas phase exist at an appropriate ratio is better along the heat transfer surface than a state in which the heat transfer surface is completely filled with a liquid phase. A phenomenon is known in which the cooling performance is improved due to the effect of the evaporation of the liquid film. Therefore, as a result of blocking the refrigerant gas generated in the lower space by the partition plate, if the ratio of the liquid phase and the gas phase on the inner upper surface of the upper space becomes appropriate, further effective improvement of the cooling performance on the upper surface can be expected. .

In this case, preferably, the partition plate is provided at least in a range that overlaps in the thickness direction of the boiling portion with the installation region of the heating element on the upper surface. According to this configuration, the partition plate can prevent the refrigerant gas generated in the lower space from gathering in the area directly below the heating element on the upper surface of the boiling section in the inner upper surface of the housing space. Therefore, it is possible to effectively prevent the refrigerant gas from gathering in the area of the inner upper surface where the heat flux density is the highest and where dryout is likely to occur.

In the configuration in which the partition plate is provided in a range overlapping the installation region of the heating element on the upper surface, preferably, the upper surface of the boiling section is formed with a through hole for communicating the accommodation space and the condensing section, and the partition plate is and a first communication passage which is provided throughout the accommodation space and penetrates the partition plate to communicate the upper space and the lower space in a region vertically overlapping the through hole in the upper surface. With this configuration, the partition plate is provided over the entire housing space, so that it is possible to reliably prevent the refrigerant gas generated in the lower space from gathering on the inner upper surface of the housing space. Further, since the refrigerant gas generated in the lower space moves along the partition plate, the refrigerant gas in the lower space can pass through the first communication passage and move toward the condensation section. Therefore, it is not necessary to form a passage for moving the refrigerant gas in the lower space to the condensation section in the boiling section separately from the partition plate, so that the structure of the boiling type cooler can be simplified.

In the configuration in which the boiling section includes a partition plate, a second communication path is preferably formed at one end portion located on the lower side of the accommodation space to communicate the upper space and the lower space. With this configuration, even when the accommodation space is divided into an upper space and a lower space, the liquid-phase refrigerant can be moved through the second communication path. Therefore, the amount of refrigerant contained can be made uniform between the upper space and the lower space without the refrigerant being concentrated in one of the upper space and the lower space.

In the above invention, preferably, the condensation section is provided so as to extend upward from the upper surface of the boiling section, and has an external fluid flow path that penetrates the condensation section in the horizontal direction. With this configuration, even when the boiling section is tilted obliquely downward, the condensation section extends along the vertical direction, so that the external fluid can be sent horizontally to the condensation section. For example, when condensing the refrigerant gas in the condensing section by forced cooling in which the external fluid is fed by the driving source, it is not necessary to tilt the driving source or the flow path of the external fluid in accordance with the tilt of the boiling section. Therefore, when the ebullient cooler is combined with external equipment, the ebullient cooler can be easily adapted to the external equipment.

According to the present invention, as described above, it is possible to increase the installation area of the heating element even in a horizontal ebullient cooler.

It is a typical perspective view showing the whole cooler composition by a 1st embodiment. FIG. 2 is a schematic longitudinal sectional view along the YZ direction of the cooler of FIG. 1; It is a typical longitudinal cross-sectional view along the EZ direction showing the internal structure of the boiling section. It is a typical enlarged vertical cross-sectional view along the X direction of the boiling section. It is a schematic plan view showing the upper surface of the boiling section. FIG. 4 is a schematic plan view showing a partition plate; It is a typical sectional view showing the second member of the boiling section. It is a schematic diagram for demonstrating operation|movement of the cooler in 1st Embodiment. It is a typical longitudinal cross-sectional view along the EZ direction of the boiling section according to the second embodiment. It is a typical longitudinal cross-sectional view along the X direction of the boiling section by 2nd Embodiment. It is a mimetic diagram for explaining operation of a cooler in a 2nd embodiment. It is a schematic diagram which showed the boiling part by a comparative example. 4 is a graph showing Experimental Result 1 with a calorific value of 50% according to an example. 10 is a graph showing Experimental Result 2 with a calorific value of 100% according to the example. 10 is a graph showing Experimental Result 3 with a calorific value of 150% according to the example. FIG. 16 is a graph summarizing the experimental results shown in FIGS. 13 to 15; FIG. It is a schematic diagram showing a modification of the direction of the condensation portion. It is the schematic diagram which showed the modification of the inclination-angle of a boiling part. It is a schematic diagram showing a modification of the formation range of the partition plate. It is a schematic diagram showing a modification in which a through hole is formed in the partition plate. It is a schematic diagram showing a modification of the first communication portion and the second communication portion.

Hereinafter, embodiments of the present invention will be described based on the drawings.

[First embodiment]
The configuration of a boiling cooler 100 (hereinafter referred to as cooler 100) according to the first embodiment will be described with reference to FIGS. 1 to 8. FIG. The cooler 100 is an ebullient cooling type cooler that absorbs heat from the heating element HS and radiates the heat to the outside by utilizing a phase change between vaporization and condensation of the refrigerant. The cooler 100 cools the heating element HS by heat absorption of the refrigerant. The refrigerant gas vaporized by endothermic cooling is condensed and returned to the liquid phase by being cooled by the external fluid.

The heating element HS is not particularly limited. The heating element HS is, for example, a device with an electronic circuit. Specifically, it is a power module that constitutes a power conversion circuit such as an inverter device. A power module is a circuit component that includes one or more switching elements for power conversion. The power conversion switching element is, for example, an IGBT (insulated gate bipolar transistor) element.

(Overall configuration of cooler)
As shown in FIG. 1, the cooler 100 includes a boiling section 10, a condensing section 20, and a connecting section 30. As shown in FIG. A space (see FIG. 2 ) for containing the refrigerant 1 is formed inside each of the boiling section 10 , the condensing section 20 and the connecting section 30 . Cooler 100 has an internal space sealed by boiling section 10 , condensing section 20 , and connecting section 30 . Refrigerant 1 is accommodated in this sealed space. Boiling section 10, condensing section 20, and connecting section 30 are made of a highly thermally conductive metal material such as aluminum (including aluminum alloy) or copper (including copper alloy).

The refrigerant 1 is not particularly limited as long as it changes phases between gas phase and liquid phase. Therefore, the coolant 1 may be selected from known ones according to the heating element HS, and may be fluorocarbon, hydrocarbon, water, or the like. The internal space of the cooler 100 is decompressed to a substantially vacuum state, and is saturated with the vapor-phase refrigerant 1 . When distinguishing the states of the refrigerant 1, for convenience, the vapor-phase refrigerant 1 is referred to as refrigerant gas 1a (see FIG. 2), and the liquid-phase refrigerant 1 is referred to as refrigerant liquid 1b (see FIG. 2).

In the following, the two directions perpendicular to each other in the horizontal plane are the X direction and the Y direction, respectively. The vertical direction orthogonal to the horizontal plane (XY plane) is defined as the Z direction. Note that the Z direction is substantially parallel to the direction of gravity, and gravity acts downward. As will be described later, the direction in which the boiling portion 10 extends is defined as the E direction. In the following description, the E direction is a direction included in the YZ plane and inclined downward by an angle θ with respect to the Y direction.

In the example shown in FIG. 1, the upper surface 12 of the boiling section 10 is provided with installation areas for four heating elements HS, and the lower surface 13 of the boiling section 10 is provided with installation areas for four heating elements HS. That is, on each of the upper surface 12 and the lower surface 13, there are installation areas of two columns in the X direction and two rows in the Y direction (strictly speaking, the E direction). The cooler 100 has a structure in which a plurality of unit structures SU are arranged in the X direction, with one row as the unit structure SU. Each unit structure SU has substantially the same structure. Therefore, one unit structure SU will be described below. Although FIG. 1 shows a configuration example with two unit structures SU, the cooler 100 may have only one unit structure SU, or may have three or more unit structures SU. may

A heating element HS is installed in the boiling section 10 . The boiling section 10 has an accommodation space 11 that accommodates the refrigerant 1, as shown in FIG. Refrigerant liquid 1b is stored in accommodation space 11 of boiling section 10 by the action of gravity. The boiling section 10 is configured to boil the refrigerant 1 (refrigerant liquid 1b) by heat exchange with the heating element HS. Boiling section 10 has an upper surface 12 and a lower surface 13 . The boiling portion 10 has two side surfaces 14 (see FIG. 1) on both sides in the X direction, and an end face 15 at one end E1 and an end face 16 at the other end E2 in the E direction. Boiling section 10 has a plate-like shape including upper surface 12 , lower surface 13 , two side surfaces 14 and two

end surfaces

15 , 16 .

An installation area for the heating element HS is provided on the one end E1 side of the boiling section 10 . The condensing section 20 is connected to the other end E2 side of the boiling section 10 via the connecting section 30 . The boiling section 10 is provided so as to extend obliquely downward from a connecting portion (that is, a connecting section 30) with the condensing section 20. As shown in FIG. The boiling section 10 is provided so as to be inclined downward by an angle θ with respect to the horizontal direction (Y direction). Thereby, the boiling section 10 extends linearly in the E direction obliquely downward from the connecting portion with the condensing section 20 . A through hole 12 a is formed in the upper surface 12 of the boiling section 10 to allow the accommodation space 11 and the condensation section 20 to communicate with each other.

The connecting portion 30 has a cylindrical shape extending in the Z direction. The lower end surface of the connecting portion 30 is joined to the upper surface 12 of the boiling portion 10 , and the upper end surface of the connecting portion 30 is joined to the lower surface of the condensing portion 20 . The lower end surface of the connecting portion 30 is inclined at an angle θ in accordance with the upper surface 12 of the boiling portion 10 which is inclined obliquely downward. The upper end surface of the connecting portion 30 extends along the horizontal plane (XY plane). The connection part 30 is provided so as to surround the through hole 12a formed in the upper surface 12 of the boiling part 10 . The connecting portion 30 connects the accommodation space 11 of the boiling portion 10 and the accommodation space 21a of the condensation portion 20 in an airtight state.

The connecting portion 30 forms a passage through which the refrigerant gas 1a vaporized in the boiling portion 10 moves to the condensing portion 20, and forms a passage through which the refrigerant liquid 1b condensed in the condensing portion 20 moves to the boiling portion 10. In the first embodiment, the movement path of the refrigerant gas 1a and the movement path of the refrigerant liquid 1b are the same. That is, the boiling section 10 and the condensing section 20 are connected by a single passage (connecting section 30). In a single passage (connecting portion 30), a gas-liquid mixed phase state is established in which the refrigerant gas 1a moving to the condensing portion 20 and the refrigerant liquid 1b moving to the boiling portion 10 are mixed. For this reason, compared to a type of cooler that forms a loop-shaped internal space in which the boiling section 10 and the condensing section 20 are separately connected by a passage dedicated to the refrigerant gas 1a and a passage dedicated to the refrigerant liquid 1b. , the device structure can be simplified.

The condensing section 20 is provided to extend upward from the upper surface 12 of the boiling section 10 via the connecting section 30 . Condensing section 20 communicates with boiling section 10 via connecting section 30 . The condensation section 20 is configured to condense the refrigerant gas 1 a from the boiling section 10 by heat exchange with the external fluid 2 .

The condensation section 20 has an accommodation space 21a that accommodates the refrigerant 1 . As shown in FIG. 1 , the condensation section 20 has a flow path 22 for the external fluid 2 that penetrates the condensation section 20 in the horizontal direction (Y direction). The flow passage 22 is a passage opened to the outside of the condensation section 20 . The accommodation space 21a (see FIG. 2) is an internal space of the condensation section 20 surrounded by the walls 24 that define the flow passages 22. As shown in FIG. In other words, the housing space 21 a and the flow passage 22 are partitioned by the wall portion 24 that constitutes the condensation portion 20 so as not to communicate with each other. The accommodation space 21a (see FIG. 2) is provided inside the refrigerant accommodation portion 21 in FIG.

In the condenser section 20, a plurality of refrigerant storage sections 21 and a plurality of flow paths 22 are alternately arranged in the X direction. Corrugated fins 23 are provided in the flow path 22 from one end to the other end in the Y direction. The external fluid 2 passing through the flow path 22 is air. As shown in FIG. 2 , when the cooler 100 is in operation, a blower 3 that blows air in the Y direction along the flow path 22 is provided as a drive source for the external fluid 2 .

The housing space 21a is open on the lower side in the Z direction, and is surrounded by walls 24 on the upper side in the X, Y and Z directions. A lower end portion of the wall portion 24 is joined to an upper end portion of the connecting portion 30 . The lower surface side of the opened accommodation space 21 a communicates with the accommodation space 11 of the boiling section 10 via the connecting portion 30 . Therefore, the cooler 100 has a closed internal space composed of the accommodation space 11 for the boiling section 10 , the interior of the connection section 30 , and the accommodation space 21 a for the condensation section 20 . A refrigerant 1 is enclosed in this internal space.

A fin 25 extending in the Z direction is provided in the housing space 21a.

As shown in FIG. 2, when the refrigerant gas 1a vaporized in the boiling section 10 flows into the housing space 21a of the condensing section 20 through the connecting section 30, it passes through the fins 25 and diffuses upward. The condenser 20 transfers the heat of the refrigerant gas 1a flowing into the housing space 21a to the external fluid 2 passing through the flow path 22 (see FIG. 1) to condense (liquefy) the refrigerant gas 1a. The refrigerant liquid 1b condensed by heat exchange with the external fluid 2 is returned to the boiling section 10 via the connection section 30 mainly by the action of gravity.

As a result, inside the cooler 100, the refrigerant 1 moves between the boiling section 10 and the condensing section 20 so as to repeat a phase change cycle of vaporization of the refrigerant 1 in the boiling section 10 and condensation of the refrigerant 1 in the condensing section 20. Circulate.

(Inclination angle of boiling part)
As shown in FIG. 2, in the first embodiment, the boiling section 10 is inclined so that the liquid surface 1c of the refrigerant 1 (refrigerant liquid 1b) is positioned within the installation area of the heating element HS on the upper surface 12. . That is, the liquid surface 1c is located in a height range between the lower end position and the upper end position of the installation area of the heating element HS on the upper surface 12 . Specifically, the liquid surface 1c is positioned at a height that substantially coincides with the upper end of the installation area of the heating element HS on the upper surface 12 . The position of the liquid surface 1c is assumed to be the position when the cooler 100 is not in operation. The installation area is an area (so-called footprint) covered with the heating element HS when the heating element HS is installed in the upper surface 12 . The boiling section 10 is provided so as to be inclined at an inclination angle θ of 5 degrees or more and less than 45 degrees with respect to the horizontal direction. In the example of FIG. 2, the tilt angle θ is 10 degrees.

(Structure of boiling part)
Next, the structure of the boiling section 10 will be described in detail with reference to FIGS. 3 to 7. FIG. As shown in FIG. 3, the boiling section 10 is configured in a hollow flat plate shape by joining lid members 43 to one end E1 and the other end E2 of a cylindrical case member 40, respectively. A case member 40 has an upper surface 12, a lower surface 13 and two side surfaces 14 (see FIG. 1). Two lid members 43 constitute the end surface 15 of the one end portion E1 and the end surface 16 of the other end portion E2. The case member 40 includes an upper first member 41 including the upper surface 12 and a lower second member 42 including the lower surface 13 .

The housing space 11 is formed to extend in the E direction from one end E1 of the boiling portion 10 to the other end E2. Hereinafter, the inner surface of the accommodation space 11 on the upper surface 12 side will be referred to as an inner upper surface 41a, and the inner surface of the accommodation space 11 on the lower surface 13 side will be referred to as an inner lower surface 42a. The inner upper surface 41 a is the inner surface of the first member 41 and the upper surface 12 is the outer surface of the first member 41 . The inner lower surface 42 a is the inner surface of the second member 42 and the lower surface 13 is the outer surface of the second member 42 . A through-hole 12 a is formed in the first member 41 to allow communication between the accommodation space 11 , the interior of the connection portion 30 (see FIG. 2 ), and the accommodation space 21 a (see FIG. 2 ) of the condensation portion 20 . The through hole 12a penetrates the first member 41 from the upper surface 12 to the inner upper surface 41a.

In the first embodiment, the boiling section 10 further includes a partition plate 44 that divides the accommodation space 11 into an upper space 11a adjacent to the upper surface 12 and a lower space 11b adjacent to the lower surface 13. The partition plate 44 is a flat plate member extending along the E direction. As shown in FIG. 4 , the partition plate 44 is provided so as to be sandwiched between the first member 41 and the second member 42 .

The partition plate 44 divides the accommodation space 11 into two spaces, an upper space 11a and a lower space 11b. Partition plate 44 is provided parallel to upper surface 12 and lower surface 13 . Therefore, the upper space 11a and the lower space 11b extend in the E direction and are provided parallel to each other. Both the upper space 11a and the lower space 11b are formed to extend in the E direction from one end E1 of the boiling section 10 to the other end E2. In the example of FIG. 4, the partition plate 44 divides the accommodation space 11 into two halves. That is, in the thickness direction of the boiling section 10, the height h1 of the upper space 11a and the height h2 of the lower space 11b are equal.

As shown in FIG. 3, the partition plate 44 is provided at least in an area OA that overlaps the installation area of the heating element HS on the upper surface 12 and the boiling section 10 in the thickness direction. The range of the length L1 in the E direction and the width W1 in the X direction (see FIG. 5) is the installation area of the heating element HS on the upper surface 12. As shown in FIG. The partition plate 44 is provided over a range that matches the range of the length L1 and the width W1 or is wider than the range of the length L1 and the width W1.

3 shows an example in which the position of the installation area of the upper surface 12 and the position of the installation area of the lower surface 13 are the same in the direction E, but the position of the installation area of the upper surface 12 and the position of the installation area of the lower surface 13 are the same. The position of the installation area need not be the same, and may be different. In the first embodiment, as an example, all the heating elements HS have the same shape (rectangular parallelepiped shape), but the individual heating elements HS may have different shapes. can also vary in size.

In the first embodiment, the partition plate 44 is provided over the entire housing space 11 (full length in the E direction and full width in the X direction). Therefore, the partition plate 44 completely divides the housing space 11 into the upper space 11a and the lower space 11b. Specifically, the accommodation space 11 has a length L in the E direction, a width W in the X direction (see FIG. 4), and a height H in the thickness direction of the boiling section 10 (see FIG. 4). The partition plate 44 is formed within the range of length L and width W, and is arranged at a position that partitions the accommodation space 11 into height h1 and height h2 in the thickness direction.

In the configuration in which the partition plate 44 partitions the entire housing space 11, as shown in FIG. be done. Therefore, the partition plate 44 has a first communication passage 45 that passes through the partition plate 44 and communicates the upper space 11a and the lower space 11b in a region that vertically overlaps the through hole 12a of the upper surface 12 . The first communication path 45 is a path for moving the refrigerant gas 1a generated in the lower space 11b to the through hole 12a, and is a path for moving the refrigerant liquid 1b returning from the condensation section 20 to the boiling section 10 to the lower space 11b. In the example of FIG. 3, the first communication path 45 is a through hole penetrating through the partition plate 44 in the thickness direction.

In addition, in the first embodiment, a second communication passage 46 is formed at one end portion E1 located on the lower side of the housing space 11 to allow the upper space 11a and the lower space 11b to communicate with each other. As shown in FIG. 2, the one end portion E1 located on the lower side is the end portion of the boiling portion 10 extending obliquely downward (in the E direction), which is relatively located on the lower side in the Z direction. means the end of The other end E2 is located relatively on the upper side in the Z direction. In the example of FIG. 3 , the second communication path 46 is a notch provided at one end of the partition plate 44 .

The second communication path 46 is provided at the one end E1 to allow the refrigerant liquid 1b to move between the upper space 11a and the lower space 11b at the lowermost portion of the housing space 11. As shown in FIG. Here, in the example shown in FIG. 2, the liquid surface 1c of the refrigerant 1 is below the first communication path 45 (upper end of the installation area of the upper surface 12). In this case, the partition plate 44 separates the refrigerant liquid 1b stored in the upper space 11a and the refrigerant liquid 1b stored in the lower space 11b. However, since the refrigerant liquid 1b can move between the upper space 11a and the lower space 11b via the second communication path 46, the liquid level in the upper space 11a and the liquid level in the lower space 11b should be aligned. , the amount of stored liquid can be adjusted.

FIG. 5 shows the planar shape of the first member 41 (boiling portion 10). On the upper surface 12 of the boiling section 10, an installation area is formed with a length L1 and a width W1, and a through hole 12a is formed with a length L2. In the example of FIG. 5, a rectangular through-hole 12a extending in the X direction is formed within the range of length L2.

6 shows the planar shape of the partition plate 44. FIG. The partition plate 44 has a through hole forming the first communication path 45 and a notch forming the second communication path 46 . A partition plate 44 is continuously formed between the first communication path 45 and the second communication path 46 without interruption. The first communication path 45 is formed by a through hole 44a. The through hole 44a has a rectangular shape. The second communication path 46 has a rectangular shape extending in the X direction.

In the example of FIG. 6, a partition plate 44 is provided in a part of the region overlapping the through hole 12a (see broken line) of the upper surface 12 in the thickness direction, on the one end E1 side. A first communication path 45 is provided in a portion of the region overlapping the through hole 12a in the thickness direction, on the side of the other end E2. In the example of FIG. 6, the partition plate 44 is provided in a region of length L4 which is approximately half of the through hole 12a on the one end E1 side of the through hole 12a formed in the range of length L2. A first communication path 45 (through hole 44a) is provided in a region of the through hole 12a, which has a length L3 that is approximately half the length of the through hole 12a on the other end E2 side.

Therefore, the refrigerant liquid 1b returning to the boiling section 10 from the condensation section 20 through the substantially half area of the through hole 12a on the one end E1 side is received by the partition plate 44 and distributed to the upper space 11a. Refrigerant liquid 1b returning to boiling section 10 from condensing section 20 through substantially half area of through hole 12a on the other end E2 side passes through first communication path 45 and is distributed to lower space 11b.

By forming the partition plate 44 on the one end E1 side and forming the first communication path 45 on the other end E2 side of the region overlapping the through hole 12a, the upper space of the condensed refrigerant liquid 1b is formed. The distribution ratio to 11a and lower space 11b can be adjusted. By increasing the ratio of the forming area of the partition plate 44, the distribution ratio of the refrigerant liquid 1b to the upper space 11a is increased. The distribution ratio increases. In the example of FIG. 6, the partition plate 44 overlaps approximately half of the through hole 12a, and the first communication path 45 also overlaps approximately half of the through hole 12a, so the distribution ratio of the refrigerant liquid 1b is the same (1:1). . The ratio of the forming area of the partition plate 44 to the forming area of the first communication path 45 (the ratio of the length L4 and the length L3 to the range of the length L2) depends on the heating element HS installed on the upper surface 12, for example. It can be set according to the ratio between the amount of heat generated and the amount of heat generated by the heating element HS installed on the lower surface 13 .

As shown in FIG. 4 , the lower space 11 b is defined by the bottom plate portion 42 b of the second member 42 , two side wall portions 42 c on both sides in the X direction, and the lower surface of the partition plate 44 . Furthermore, as shown in FIG. 7, the lower space 11b is partitioned into a plurality of refrigerant passages 42e by partition walls 42d extending in the E direction. In the example of FIG. 7, three partitions 42d are provided, and the lower space 11b is partitioned into four refrigerant passages 42e. As shown in FIG. 4 , the upper surfaces of the two side wall portions 42 c on both sides in the X direction and the upper surfaces of the three partition wall portions 42 d are in contact with the lower surface of the partition plate 44 .

The through hole 44a (see FIG. 6) forming the first communication path 45 is formed so as to straddle the formation positions of the four coolant paths 42e in the lower space 11b. The width of the through hole 44a in the X direction is approximately equal to the total width of the coolant passages 42e in the X direction.

As shown in FIG. 4, the first member 41 forming the upper space 11a substantially matches the structure of the second member 42, which is vertically symmetrical, except that the through hole 12a (see FIG. 5) is formed. do. The upper space 11 a is defined by the top plate portion 41 b of the first member 41 , two side wall portions 41 c on both sides in the X direction, and the upper surface of the partition plate 44 . The upper space 11a is partitioned into a plurality of coolant passages 41e by partition walls 41d extending in the E direction. In the example of FIG. 4, three partition walls 41d are provided, and the upper space 11a is partitioned into four refrigerant passages 41e. The bottom surface of each of the two side wall portions 41 c on both sides in the X direction and the bottom surfaces of the three partition wall portions 41 d are in contact with the upper surface of the partition plate 44 .

The length in the X direction of the second communication path 46 (see FIG. 6) formed in a notch shape in the partition plate 44 is equal to the length of the pair of side wall portions 42c (the pair of side wall portions 41c) on both sides in the X direction shown in FIG. ) is approximately equal to the interval of That is, the second communication path 46 is formed across the four coolant paths 42e in the lower space 11b and the four coolant paths 41e in the upper space 11a. Thereby, the second communication path 46 is configured to allow a plurality of (eight) paths provided in the upper space 11a and the lower space 11b to communicate with each other.

As shown in FIG. 4, the first member 41 and the second member 42 are joined to the partition plate 44 and integrated. The partition plate 44 is made of a brazing sheet provided with brazing material on both sides. The upper and lower surfaces of the partition plate 44 are flat surfaces. The boiling section 10 is formed by arranging lid members 43 on one end E1 and the other end E2 of the assembly (case member 40) of the first member 41, the second member 42, and the partition plate 44 and brazing them. ,It is configured.

(Operation of cooler)
The operation of cooler 100 will be described. FIG. 8 is a schematic diagram of the boiling section 10 of the cooler 100. As shown in FIG. When the heating element HS generates heat, the heat generated by the refrigerant 1 in the boiling section 10 is absorbed. The heat of the heating element HS arranged on the upper surface 12 is absorbed by the refrigerant 1 accommodated in the upper space 11a, and the heat of the heating element HS arranged on the lower surface 13 is absorbed by the refrigerant 1 accommodated in the lower space 11b. be done. The boiling portion 10 is inclined downward at an angle θ, and the liquid surface 1c of the refrigerant 1 is positioned at the upper end of the installation area. is in contact with Therefore, the inner upper surface 41a is prevented from being covered with the refrigerant gas 1a due to disappearance of the refrigerant liquid 1b. In each of the upper space 11a and the lower space 11b, the heat-absorbing refrigerant 1 boils and evaporates into a refrigerant gas 1a.

The refrigerant gas 1a generated in the upper space 11a moves along the inner upper surface 41a toward the other end E2. Since the inner upper surface 41a is inclined upward at an angle θ toward the other end E2, the refrigerant gas 1a is prevented from remaining on the inner upper surface 41a without moving. When the refrigerant gas 1a discharged from the liquid surface 1c reaches the formation position of the through hole 12a, the refrigerant gas 1a moves into the connecting portion 30 through the through hole 12a.

The refrigerant gas 1a generated in the lower space 11b moves upward in the lower space 11b, contacts the lower surface of the partition plate 44, and moves along the partition plate 44 toward the other end E2. The partition plate 44 prevents the refrigerant gas 1a generated in the lower space 11b from moving upward to the inner upper surface 41a of the upper space 11a and excessively concentrating the refrigerant gas 1a on the inner upper surface 41a. When the refrigerant gas 1a released from the liquid surface 1c reaches the formation position of the first communication path 45, the refrigerant gas 1a passes through the first communication path 45 and moves into the upper space 11a. The refrigerant gas 1a that has moved into the upper space 11a passes upward through the upper space 11a and moves into the connecting portion 30 through the through hole 12a.

The refrigerant gas 1a passes upward through the connection portion 30 and flows into the accommodation space 21a of the condensation portion 20 located above. Inside the housing space 21 a , the refrigerant gas 1 a moves upward while diffusing through the gaps between the fins 25 .

As shown in FIG. 2, in the condenser section 20, heat exchange takes place between the refrigerant gas 1a in the housing space 21a and the external fluid 2 passing through the flow passage 22 (see FIG. 1). Through heat exchange, the refrigerant gas 1a releases the heat of condensation to the external fluid 2 and condenses into the refrigerant liquid 1b. The condensed refrigerant liquid 1b drops from the housing space 21a into the connecting portion 30 and returns to the refrigerant liquid 1b stored in the boiling section 10 through the through hole 12a.

(Effect of the first embodiment)
The following effects can be obtained in the first embodiment.

In the first embodiment, as described above, the boiling portion 10 is provided so as to extend obliquely downward from the connecting portion (connecting portion 30) with the condensing portion 20. The internal upper surface 41a can be inclined with respect to the liquid surface 1c of the refrigerant liquid 1b so that the internal upper surface 41a of the housing space 11 can be continuously in contact with the refrigerant liquid 1b. Since the accommodation space 11 is inclined upward toward the condensation section 20 , the refrigerant gas 1 a vaporized inside the accommodation space 11 moves toward the condensation section 20 along the inclined accommodation space 11 . Therefore, it is possible to prevent the refrigerant gas 1a from staying excessively on the inner upper surface 41a of the housing space 11 . As a result, sufficient cooling performance can be exhibited even for the heating element HS installed on the upper surface 12 of the boiling section 10, so that the heating element HS can be installed not only on the lower surface 13 of the boiling section 10 but also on the upper surface 12. By doing so, even in the horizontal ebullient cooler 100, the installation area of the heating element HS can be increased.

Further, in the first embodiment, as described above, the boiling section 10 is inclined at an inclination angle θ of 5 degrees or more and less than 45 degrees with respect to the horizontal direction, so that the height dimension of the boiling cooler 100 is A horizontal ebullient cooler 100 that has the merit of the horizontal ebullient cooler 100 that it is possible to suppress heat generation and has a larger installation area for the heat generator HS by enabling the heat generator HS to be installed on the upper surface 12 of the boiling section 10. - 特許庁is obtained.

In the first embodiment, as described above, the boiling section 10 includes the partition plate 44 that divides the accommodation space 11 into the upper space 11a adjacent to the upper surface 12 and the lower space 11b adjacent to the lower surface 13. Further, since it is included, the partition plate 44 can block the refrigerant gas 1a generated in the lower space 11b of the accommodation space 11 from moving to the upper space 11a. Therefore, it is possible to prevent the entire refrigerant gas 1a from gathering on the inner upper surface 41a and preventing the contact between the refrigerant liquid 1b and the inner upper surface 41a. can be done. In addition, in a heat exchanger, a state in which a liquid phase and a gas phase exist at an appropriate ratio is better along the heat transfer surface than a state in which the heat transfer surface is completely filled with a liquid phase. A phenomenon is known in which the cooling performance is improved due to the effect of the evaporation of the liquid film. Therefore, as a result of blocking the refrigerant gas 1a generated in the lower space 11b by the partition plate 44, when the ratio of the liquid phase and the gas phase in the inner upper surface 41a of the upper space 11a becomes appropriate, the cooling performance in the upper surface 12 is further improved. Effective improvement is expected.

In addition, in the first embodiment, as described above, the partition plate 44 is provided at least in the range OA that overlaps the installation region of the heating element HS on the upper surface 12 and the boiling section 10 in the thickness direction. The partition plate 44 prevents the refrigerant gas 1a generated in the lower space 11b from gathering in the area directly below the heating element HS on the upper surface 12 of the boiling section 10 in the inner upper surface 41a. Therefore, it is possible to effectively prevent the refrigerant gas 1a from concentrating on the region of the inner upper surface 41a where dryout is most likely to occur.

In addition, in the first embodiment, as described above, the partition plate 44 is provided over the entire housing space 11, so that the refrigerant gas 1a generated in the lower space 11b does not reach the inner upper surface 41a of the housing space 11. You can definitely prevent them from gathering. Further, the partition plate 44 has a first communication passage 45 penetrating through the partition plate 44 and communicating the upper space 11a and the lower space 11b in a region vertically overlapping the through hole 12a of the upper surface 12. Therefore, the lower space 11b can pass through the first communication passage 45 and move toward the condensation section 20 . Therefore, it is not necessary to form a passage in the boiling section 10 separately from the partition plate 44 for moving the refrigerant gas 1a in the lower space 11b to the condensation section 20, thereby simplifying the structure of the boiling type cooler.

In addition, in the first embodiment, as described above, the second communication path 46 that connects the upper space 11a and the lower space 11b is formed at the lower end E1 of the accommodation space 11. Therefore, even when the accommodation space 11 is divided into the upper space 11a and the lower space 11b, the refrigerant liquid 1b can be moved through the second communication path 46. As shown in FIG. Therefore, the storage amount of the refrigerant liquid 1b can be made uniform between the upper space 11a and the lower space 11b without the refrigerant liquid 1b being unevenly stored in one of the upper space 11a and the lower space 11b. In addition, in the first embodiment, the second communication path 46 communicates the four refrigerant passages 42e in the lower space 11b and the four refrigerant passages 41e in the upper space 11a with each other. It is also possible to suppress the variation in the amount of the refrigerant liquid 1b contained.

Further, in the first embodiment, as described above, the condensation section 20 is provided so as to extend upward from the upper surface 12 of the boiling section 10, and the flow path 22 for the external fluid 2 that penetrates the condensation section 20 in the horizontal direction. Therefore, even when the boiling section 10 is tilted obliquely downward, the external fluid 2 can be sent horizontally to the condensing section 20 extending along the vertical direction. Therefore, in the configuration in which the refrigerant gas 1a in the condensation section 20 is condensed by forced cooling in which the external fluid 2 is sent by the drive source (blower 3), the drive source and the circulation path of the external fluid 2 are tilted according to the inclination of the boiling section 10. You don't have to put it all together. Therefore, when combining the ebullient cooler 100 with an external device, the ebullient cooler 100 can be easily adapted to the external device.

[Second embodiment]
Next, referring to FIGS. 9 to 11, the configuration of a boiling cooler 200 (hereinafter referred to as cooler 200) according to a second embodiment of the present invention will be described. In the second embodiment, unlike the first embodiment in which the partition plate 44 is provided in the accommodation space 11 of the boiling section 10, an example in which the partition plate 44 is not provided in the accommodation space 11 of the boiling section 10 will be described.

In addition, in the second embodiment, the same reference numerals are used for the same configuration as in the first embodiment, and the description thereof is omitted. In particular, in the second embodiment, the external shape of the boiling section 10 other than the internal structure of the boiling section 10, and the configurations of the condensing section 20 and the connecting section 30 are the same as those of the first embodiment shown in FIG. As shown in FIG. 12, also in the second embodiment, the boiling section 10 is provided so as to extend obliquely downward from a connecting portion (connecting section 30) with the condensing section 20, and extends in the horizontal direction (Y direction). is inclined downward by an angle θ with respect to Only the internal structure of the boiling section 10 will be described below.

As shown in FIG. 9, the partition plate 44 is not provided in the housing space 11 of the boiling section 10 in the second embodiment. That is, the accommodation space 11 is not partitioned into the upper space 11a and the lower space 11b, but is a continuous space as a whole. As shown in FIG. 10 , the accommodation space 11 includes an inner upper surface 41 a of the first member 41 , an inner lower surface 42 a of the second member 42 , a side wall portion 41 c of the first member 41 and a side wall portion 42 c of the second member 42 . , a lid member 43 (see FIG. 9) at one end E1 and a lid member 43 (see FIG. 9) at the other end E2. The housing space 11 is partitioned into four refrigerant passages by three

partition walls

41d and 42d, as in the first embodiment. Since the partition plate 44 is not provided, each refrigerant passage is formed from the inner lower surface 42 a to the inner upper surface 41 a and has a height equal to the height H of the housing space 11 .

In the second embodiment, since the partition plate 44 is not provided, the case member 40 does not have to be composed of two members, the first member 41 and the second member 42 . For example, the cylindrical case member 40 may be formed as a single member by integrating the first member 41 and the second member 42 by extrusion molding.

Other configurations of the second embodiment are the same as those of the first embodiment.

(Operation of cooler)
As shown in FIG. 11, in the second embodiment, similarly to the first embodiment, the boiling section 10 is inclined downward at an angle θ, and the liquid surface 1c of the refrigerant 1 is at the upper end of the installation area. Located in Therefore, the inner upper surface 41a of the upper space 11a is always in contact with the refrigerant liquid 1b.

In the second embodiment, the refrigerant gas 1a generated near the inner lower surface 42a of the accommodation space 11 by the heat of the heating element HS provided on the lower surface 13 moves toward the inner upper surface 41a without being blocked on the way. Therefore, in the second embodiment, both the refrigerant gas 1a generated on the inner upper surface 41a side and the refrigerant gas 1a generated on the inner lower surface 42a side move along the inner upper surface 41a toward the other end E2. . Since the inner upper surface 41a is inclined upward at an angle θ toward the other end E2, it is possible to prevent the refrigerant gas 1a from remaining on the inner upper surface 41a without moving.

When the refrigerant gas 1a reaches the position where the through hole 12a is formed, the refrigerant gas 1a moves into the connecting portion 30 through the through hole 12a. Other operations of the cooler 100 are the same as those of the first embodiment.

(Effect of Second Embodiment)
In the second embodiment, as in the first embodiment, the boiling section 10 is provided so as to extend obliquely downward from the connection section 30 with the condensing section 20, so that the inner upper surface 41a of the accommodation space 11 and the refrigerant liquid 1b can be continuously brought into contact with each other, and the refrigerant gas 1a can be prevented from remaining excessively on the inner upper surface 41a. As a result, sufficient cooling performance can be exhibited even for the heating element HS installed on the upper surface 12 of the boiling section 10, so that the heating element HS can be installed not only on the lower surface 13 of the boiling section 10 but also on the upper surface 12. By doing so, even in the horizontal ebullient cooler 100, the installation area of the heating element HS can be increased.

Other effects of the second embodiment are the same as those of the first embodiment.

[Example]
Next, experimental results for confirming the effects of the cooler 100 of the first embodiment and the cooler 200 of the second embodiment will be described.

(Structure of boiling section)
In the example, cooling performance was measured under the same operating conditions for each of the cooler 100 of the first embodiment and the cooler 200 of the second embodiment. Specifically, as variations in the structure of the boiling section 10, the cooling performance was measured for two types of boiling sections, one with the partition plate 44 (first embodiment) and the other without the partition plate 44 (second embodiment).

(tilt angle)
Regarding the angle θ of the boiling section 10, the cooling performance was measured under a plurality of conditions. Specifically, the measurement was performed under three conditions of θ=5 degrees, θ=10 degrees, and θ=0 degrees (horizontal) shown in FIG. 12 as a comparative example.

(Operating conditions)
Also, assuming that the amount of heat generated by the heating element HS changes during actual operation, measurements were performed under a plurality of heat generation conditions. Specifically, the amount of heat generated during rated operation assumed for the heating element HS made up of the power module was assumed to be 100%, and measurements were made under three conditions of 50%, 100%, and 150%.

Therefore, 50%, 100% for 6 types of combinations of 3 types of inclination angles θ = 10 degrees, 5 degrees, 0 degrees (0 degrees is a comparative example) for 2 types of structures with and without partition plates. , 150% cooling performance was measured.

13 to 15 are graphs showing the measurement results of cooling performance. 13 to 15 show the measurement results of heat generation conditions with a heat generation amount of 50%, a heat generation amount of 100%, and a heat generation amount of 150%, respectively. The horizontal axis of each graph in FIGS. 13 to 15 indicates the temperature measurement position. The temperature measurement positions are each of six measurement positions set at intervals along the E direction in the installation area of the heating element HS in the boiling section 10 . In the installation area, the measurement position No. 1 is closest to the one end E1, and the measurement position No. 6 is closest to the other end E2. The vertical axis of each graph indicates the difference value ΔT[K] between the mounting surface temperature of the heating element HS and the internal coolant temperature at each temperature measurement position. Since the heating element HS is installed on each of the upper surface 12 and the lower surface 13, the measured value of the upper surface 12 and the measured value of the lower surface 13 are obtained for the same temperature measurement position. The smaller the difference value ΔT, the higher the cooling performance. Each graph shows the design value (theoretical value) of the difference value ΔT calculated from the specifications of the boiling section 10 and the set value of the heat generation amount of the heating element HS without considering the behavior of the refrigerant gas 1a. A line (thick line) is shown as a guide for cooling performance evaluation. The baseline values differ according to the calorific value conditions (50%, 100%, 150%).

A graph that summarizes the graphs in FIGS. 13 to 15 is shown in FIG. The vertical axis in FIG. 16 is the same difference value ΔT[K] as in FIGS. The horizontal axis represents the experimental conditions, and shows the values of the top surface and the bottom surface for each of the six types of combinations of the presence or absence of the partition plate and the inclination angle θ. In FIG. 16, the measurement results of the calorific value of 50% (see FIG. 13), the calorific value of 100% (see FIG. 14), and the calorific value of 150% (see FIG. 15) are indicated by different hatching. . Each measurement result is shown as a bar graph showing the range of maximum and minimum values of ΔT at six temperature measurement positions. The lower the position of the plotted bar, the lower the value of ΔT, and the shorter the length of the bar, the smaller the difference between the maximum and minimum values of ΔT.

(Comparison of tilt angles)
13 to 15, the influence of the tilt angle on the cooling performance will be studied. Plots A1, A2 and A3 represent measurement results of θ=10 degrees, 5 degrees and 0 degrees for the upper surface 12 of the boiling section 10 with the partition plate. Plots A1 and A2 in which the boiling section 10 is inclined are positioned below plot A3 of the comparative example. Also, the plots A1 and A2 have smaller variations in ΔT than the plot A3.

Plots A4, A5 and A6 represent measurement results of θ=10 degrees, 5 degrees and 0 degrees for the lower surface 13 of the boiling section 10 with the partition plate. These measurement results of the lower surface 13 do not differ as much as the measurement results of the upper surface 12 (A1 to A3).

Plots B1, B2, and B3 represent measurement results for θ=10 degrees, 5 degrees, and 0 degrees for the upper surface 12 of the boiling section 10 without a partition plate. Plots B1 and B2 in which the boiling section 10 is inclined are positioned below plot B3 of the comparative example. Plots B1 and B2 have smaller variations in ΔT than plot B3.

Plots B4, B5 and B6 represent measurement results of θ=10 degrees, 5 degrees, and 0 degrees for the lower surface 13 of the boiling section 10 with the partition plate. The measurement results of the lower surface 13 do not differ as much as the measurement results of the upper surface 12 (B1 to B3).

Focusing on the measurement results of the upper surface 12, the measurement results (A1, A2, B1, B2) at θ=10 degrees and θ=5 degrees consistently show that ΔT falls near the reference line in FIGS. there is On the other hand, the measurement results of θ=0 degrees (A3, B3) according to the comparative example show that ΔT is above the reference line in FIGS. The gap with (A1, A2, B1, B2) is also large. The measurement results (A1, A2, B1, B2) at θ=10 degrees and θ=5 degrees on the upper surface 12 are the measurement results (A4, A5, B4, B5) at θ=10 degrees and θ=5 degrees on the lower surface 13. The value of ΔT is smaller than or equal to .

For this reason, by inclining the boiling section 10 obliquely downward from the horizontal direction as in the first and second embodiments, the cooling performance on the upper surface 12 is improved, and the cooling performance on the lower surface 13 is equal to or lower than that on the lower surface 13 It was confirmed that the above cooling performance can also be obtained on the upper surface 12 .

In addition, in FIG. 15, which is a condition in which the amount of heat generated is large, the value of ΔT in the measurement results (A2, B2) at θ=5 degrees is large, and the variation in ΔT between the temperature measurement positions is large. On the other hand, in the measurement results (A1, B1) when θ=10 degrees, ΔT is a value below the reference line at any temperature measurement position, and it can be seen that the variation is small. This trend is not seen at calorific value of 50% (Fig. 13) and calorific value of 100% (Fig. 14). From this, it was confirmed that increasing the inclination angle θ is effective in maintaining the cooling performance (expanding the permissible range of the heat generation amount) especially under high load conditions where the heat generation amount is large.

(Comparison with and without partition plate)
Next, the influence of the presence or absence of the partition plate on the cooling performance will be examined. When .theta.=10 degrees and the case where the partition plate is present (A1) and the case where the partition plate is not present (B1) are compared on the upper surface 12, the value of .DELTA.T is the same or smaller in the case where the partition plate is present.

When θ=5 degrees and the upper surface 12 with the partition plate (A2) and without the partition plate (B2) are compared, the value of ΔT is smaller with the partition plate. In particular, under high-load conditions where the amount of heat generated is 150%, the provision of the partition plate 44 greatly reduces the value of ΔT. Thus, it was confirmed that the provision of the partition plate 44 can improve the cooling performance (reduce the value of ΔT). Further, from the results of examination of the inclination angle θ, it was confirmed that the cooling performance under high load conditions can be greatly improved by increasing the inclination angle θ. It has been confirmed that it is possible to improve the cooling performance by providing them.

[Modification]
It should be noted that the embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the above description of the embodiments, and includes all modifications (modifications) within the scope and meaning equivalent to the scope of the claims.

For example, in the above-described first and second embodiments, the heating element HS is a power module used in a power conversion device, but the present invention is not limited to this. In the present invention, the heating element can be of any kind. The heating element may be a semiconductor chip such as a CPU or an electronic circuit mounted in an electronic device such as a server.

In addition, in the first and second embodiments, the condensation section 20 is provided to extend upward from the upper surface 12 of the boiling section 10, and has the flow path 22 for the external fluid 2 that penetrates the condensation section 20 in the horizontal direction. Although an example has been given, the invention is not so limited. In the present invention, the condensation section 20 may be provided so as to extend in a direction other than the upward direction, and the flow path 22 for the external fluid 2 may be provided so as to pass through the condensation section 20 in a direction other than the horizontal direction. may

For example, in the example shown in FIG. 17, the condensation section 20 is provided so as to protrude in the horizontal direction (Y direction) with respect to the connection section 30 rising upward from the boiling section 10 . A flow passage 22 for the external fluid 2 is provided so as to pass through the condensation section 20 in the vertical direction (Z direction). The external fluid 2 is passed upward through the flow passage 22 by, for example, the blower 3 arranged below the condenser section 20 . Conversely, the external fluid 2 may be passed downward through the flow passage 22 by means of a blower arranged above the condenser section 20 .

Also, in the first and second embodiments, an example in which the connecting portion 30 is provided to connect the condensing portion 20 and the boiling portion 10 is shown, but the present invention is not limited to this. In the present invention, the condensing section 20 may be directly connected to the top surface 12 of the boiling section 10 . That is, the lower end of the housing space 21a of the condensation unit 20 communicates with the through hole 12a of the upper surface 12 of the boiling unit 10, and the wall 24 of the condensation unit 20 is formed such that the housing space 21a and the housing space 11 are closed spaces. may be joined to the upper surface 12 of the boiling portion 10 .

Also, in the first and second embodiments, an example in which the boiling section 10 and the condensing section 20 are connected by a single passage (connecting section 30) is shown, but the present invention is not limited to this. In the present invention, for example, a first passage for passing the refrigerant gas 1a moving to the condensing section 20 and a second passage for passing the refrigerant liquid 1b moving to the boiling section 10 are provided to form a circulation path for the refrigerant 1. It may be configured in a loop shape.

In addition, in the first and second embodiments, the examples where the angle θ of the boiling section 10 is 5 degrees and 10 degrees are shown, but the present invention is not limited to this. The angle θ may be an angle of 5 degrees or more and less than 10 degrees, or may be an angle of more than 10 degrees. For example, the example shown in FIG. 18 shows an example of θ=30 degrees.

In addition, in the first and second embodiments, the installation area of the upper surface 12 and the installation area of the lower surface 13 of the boiling section 10 are provided at the same position and in the same range (length L1 range) in the direction E. However, the present invention is not limited to this. The installation area of the upper surface 12 and the installation area of the lower surface 13 may be provided at different positions and in different ranges. For example, in the example shown in FIG. 18, the upper surface 12 of the boiling section 10 is provided with two installation areas, and the lower surface 13 is provided with three installation areas. In particular, the installation area on the other end E2 side of the lower surface 13 is arranged at a position aligned with the condensation section 20 in the Z direction. According to the configuration of this modification, more heating elements HS can be installed.

In addition, in the first and second embodiments, the liquid surface 1c of the refrigerant 1 is set within the installation area of the heating element HS on the upper surface 12 of the boiling section 10 when the cooler is not in operation. However, the present invention is not limited to this. In the present invention, the liquid surface 1c may be set at a position above the installation area of the heating element HS on the upper surface 12. FIG. With this configuration, the entire area of the inner upper surface 41a of the housing space 11 facing the installation area of the heat generating element HS (the area immediately below the heat generating element HS) can be brought into contact with the refrigerant liquid 1b.

Also, in the first embodiment, an example in which the partition plate 44 is provided over the entire accommodation space 11 was shown, but the present invention is not limited to this. In the present invention, the partition plate 44 may be locally provided in part of the housing space 11 . For example, in the example shown in FIG. 19, the partition plate 44 is provided in the area OA where the heating element HS installation area on the upper surface 12 overlaps the boiling section 10 in the thickness direction, and is not provided in other areas. Even in this case, the partition plate 44 can prevent the refrigerant gas 1a from the lower space 11b from gathering on the inner upper surface 41a directly below the area where the heating element HS is installed on the upper surface 12 .

Also, in the first embodiment, an example in which the height h1 of the upper space 11a and the height h2 of the lower space 11b are equal was shown, but the present invention is not limited to this. In the present invention, the height h1 of the upper space 11a and the height h2 of the lower space 11b may be different. For example, the height h1 of the upper space 11a and the height h2 of the lower space 11b are changed according to the amount of heat generated by the heating element HS installed on the upper surface 12 and the amount of heat generated by the heating element HS installed on the lower surface 13. May be set.

In addition, in the first embodiment, the partition plate 44 is formed only with the first communication passage 45 formed of a through hole and the second communication passage 46 formed of a notch. Although an example in which is not formed has been shown, the present invention is not limited to this. In the present invention, the partition plate 44 may be provided with a through hole or a notch for adjusting the passage amount of the refrigerant gas 1a. For example, in the example of FIG. 20, the partition plate 44 is provided with a plurality of through holes 441 . The through-hole 441 is provided in a range overlapping the installation region of the heating element HS on the upper surface 12 and the boiling section 10 in the thickness direction. The through hole 441 is configured to allow part of the refrigerant gas 1a generated in the lower space 11b to pass through to the upper space 11a. The through hole 441 is formed to have a size that allows the amount of refrigerant gas 1a passing through the through hole 441 to be an appropriate amount. As a result, the ratio between the amount of the refrigerant liquid 1b and the amount of the refrigerant gas 1a on the inner upper surface 41a can be adjusted, and the cooling performance on the upper surface 12 side can be effectively improved under the condition that the refrigerant liquid 1b and the refrigerant gas 1a exist in an appropriate ratio. can be significantly improved.

In addition, in the above-described first embodiment, an example in which the first communication path 45 is formed by a through hole formed in the partition plate 44 is shown, but the present invention is not limited to this. For example, when the partition plate 44 is partially provided in the accommodation space 11 as shown in FIG. The first communication path 45 may not be provided. Further, when the partition plate 44 is provided over the entire housing space 11, the first communication passage 45 is configured by a notch formed in the other end portion of the partition plate 44 in the same manner as the second communication passage 46. may For example, as shown in FIG. 21, a lid member 43 closing the other end E2 of the boiling section 10 is formed with a recess 43a extending over the upper space 11a and the lower space 11b. A passageway 45 may be configured.

Further, in the first embodiment, an example is shown in which the second communication path 46 is formed by a notch formed in the partition plate 44, but the present invention is not limited to this. For example, the second communication path 46 may be configured by a through hole formed in the partition plate 44 in the same manner as the first communication path 45 . Further, as shown in FIG. 21, for example, the lid member 43 closing the one end E1 of the boiling section 10 is formed with a recess 43b extending over the upper space 11a and the lower space 11b. 46 may be configured. Also, in the present invention, the second communication path 46 may not be provided.

Further, in the above-described first embodiment, an example in which each of the upper space 11a and the lower space 11b is partitioned into a plurality (four) of

refrigerant passages

41e and 42e by the

partition walls

41d and 42d is shown, and in the above-described second embodiment, Although an example in which the accommodation space 11 is partitioned into a plurality of (four) refrigerant passages by the

partition walls

41d and 42d has been shown, the present invention is not limited to this. In the present invention, the accommodation space 11 (upper space 11a and lower space 11b) does not have to be partitioned into a plurality of refrigerant passages.

REFERENCE SIGNS LIST 1 refrigerant 1a refrigerant gas 1b refrigerant liquid 1c, 1d liquid surface 2 external fluid 10 boiling section 11 accommodation space 11a upper space 11b lower space 12 upper surface 12a through hole 13 lower surface 20 condensing section 22 flow path 30 connection section 44 partition plate 45 first first Communication path 46

Second communication path

100, 200 Cooler (boiling cooler)
E1 One end E2 Other end HS Heating element θ Inclination angle

Claims

a boiling portion that has an accommodation space that accommodates a refrigerant and causes the refrigerant to boil by heat exchange with a heating element;
a condensing section that communicates with the boiling section and condenses the refrigerant gas from the boiling section by heat exchange with an external fluid;
The boiling section is formed in a plate-like shape having an upper surface and a lower surface on which the heating element is installed, respectively, and is provided so as to extend obliquely downward from a connection portion with the condensation section. .
2. The boiling type according to claim 1, wherein the boiling portion is inclined so that the liquid level of the refrigerant is positioned within or above the installation area of the heating element on the upper surface. Cooler.
The boiling type cooler according to claim 2, wherein the boiling section is inclined at an inclination angle of 5 degrees or more and less than 45 degrees with respect to the horizontal direction.
The boiling type cooler according to claim 1, wherein the boiling section further includes a partition plate that divides the housing space into an upper space adjacent to the upper surface and a lower space adjacent to the lower surface.
The boiling type cooler according to claim 4, wherein the partition plate is provided in a range that overlaps at least the installation region of the heating element on the upper surface and the boiling section in the thickness direction.
A through-hole is formed in the upper surface of the boiling section for communicating the accommodation space and the condensation section,
The partition plate is provided over the entire housing space, and penetrates the partition plate to communicate the upper space and the lower space in a region vertically overlapping the through hole of the upper surface. 6. Evaporative cooler according to claim 5, having one communication passage.
The boiling type cooler according to claim 4, wherein a second communication passage is formed at one end portion located on the lower side of the housing space for communicating the upper space and the lower space.
2. The boiling type cooler according to claim 1, wherein said condensation section extends upward from said upper surface of said boiling section and has a flow path for said external fluid that horizontally penetrates said condensation section.