Cooling system

Abstract

To provide a cooling system that can improve cooling performance. [Solution] In a cooling system comprising a piping 7 through which a refrigerant 4 flows, and a cooler 10 connected to the piping 7 and having a refrigerant flow path 11 through which the refrigerant 4 flowing from the piping 7 flows, a swirling flow forming unit 73 is provided in the upstream piping 71 connected to the upstream side of the cooling system 2 of the piping 7, which generates a secondary flow 30 that becomes a swirling flow, thereby transmitting the swirling flow into the refrigerant flow path 11 in the cooler 10.

Description

Technical Field

[0001] The present disclosure relates to a cooling system that cools heat-generating components with a cooling device through which a refrigerant flows.

Background Art

[0002] Conventionally, Patent Document 1 has proposed a structure capable of improving the cooling effect of a heat sink provided with cooling fins. This heat sink constitutes a swirling flow generating means by forming grooves in the cooling fins provided directly below the cooling surface that cools the heat-generating component, and generates a swirling flow in the cooling air flowing between the cooling fins to improve the cooling effect.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] However, as with the heat sink disclosed in Patent Document 1, it is not possible to sufficiently generate a swirling flow only by forming grooves in the cooling fins provided inside the heat sink. That is, the grooves are formed in the limited space of the cooling fins, and only a limited number of grooves can be formed, resulting in an insufficient swirling flow. For this reason, sufficient cooling performance cannot be obtained.

[0005] The present disclosure aims to provide a cooling system that can improve cooling performance.

Means for Solving the Problems

[0006] A first aspect of the present disclosure is a cooling system that cools a heat-generating component (3), comprising: a pipe (7) through which a refrigerant (4) flows, The cooling device (1) includes a cooler (10) connected to the aforementioned piping and having a refrigerant flow path (11) through which the refrigerant flowing from the aforementioned piping flows, The upstream pipe (71) of the aforementioned piping, which is connected to the upstream side of the cooling device, is equipped with a swirling flow forming unit (73) that generates a secondary flow (30) which becomes a swirling flow, thereby transmitting the swirling flow into the refrigerant flow path in the cooler.

[0007] Thus, by providing a swirling flow generating section in the upstream piping, a secondary flow can be generated in addition to the main flow within the upstream piping when the refrigerant flows through the swirling flow generating section. This secondary flow becomes a swirling flow, flowing in the direction of the main flow while swirling. Furthermore, as this secondary flow flows into the cooler, it acts to separate the refrigerant near the cooling surface that contributes to the cooling of heat-generating components from the cooling surface. Therefore, it becomes possible to increase the flow velocity of the refrigerant at the cooling surface, thereby improving the cooling performance for cooling the heat-generating components 3.

[0008] The reference numerals in parentheses attached to each component indicate an example of the correspondence between that component and the specific components described in the embodiments described later. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a schematic configuration of a cooling system according to the first embodiment of this disclosure. [Figure 2] This is a top view layout diagram of the cooling system and its surrounding piping. [Figure 3] Figure 2 is a view from the bottom of the page. [Figure 4] This is a cross-sectional view taken along line IV-IV in Figure 2. [Figure 5] This is a cross-sectional view of VV in Figure 3. [Figure 6] This is a top view layout diagram of a cooling device and its piping in the vicinity according to a second embodiment of the present disclosure. [Figure 7] Figure 6 is a view from the bottom of the page. [Figure 8]This is a top view layout diagram of a cooling device and its piping in the vicinity according to a third embodiment of the present disclosure. [Figure 9] This is a cross-sectional view taken along line IX-IX in Figure 8. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. In each embodiment, including the other embodiments described below, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0011] (First Embodiment) A first embodiment of this disclosure will be described. The cooling system 1 shown in Figure 1 is a boiling cooling system that cools a heat-generating component 3 attached to a cooling device 2 with a refrigerant 4.

[0012] As shown in Figure 1, the cooling system 1 includes a cooling device 2 to which the heat-generating component 3 is attached, as well as components such as a pump 5 and a heat sink 6, and is constructed by assembling each component into piping 7 that circulates the refrigerant 4.

[0013] The cooling device 2 is a heat exchanger that cools the heat-generating component 3 by exchanging heat with the refrigerant 4 flowing inside it. When the heat-generating component 3 attached to the cooling device 2 generates heat, that heat is transferred to the refrigerant 4 flowing inside the cooling device 2, thereby cooling the heat-generating component 3. The heat-generating component 3 to be cooled is a semiconductor element that generates heat when an electric current is applied, such as a semiconductor switching element in a power conversion device in a vehicle. Examples of semiconductor switching elements include power MOSFETs (metal-oxide-semiconductor field-effect transistors) and IGBTs (Insulated Gate Bipolar Transistors).

[0014] The refrigerant 4 circulated in the cooling system 1 is a subcooled liquid whose temperature is lower than the boiling point. For example, the refrigerant 4 may be water, LLC (abbreviation for Long Life Coolant), or an electrically insulating liquid such as a fluorine-based inert liquid. The pressure of the refrigerant 4 is adjusted such that its boiling point is sufficiently lower than the average temperature of the heat-generating component 3 during operation. The pump 5 sucks and discharges the refrigerant 4 in the pipe 7 to supply it to the cooling device 2, enabling the cooling device 2 to cool the heat-generating component 3. The radiator 6 dissipates heat from the refrigerant 4 whose temperature has risen due to the cooling of the heat-generating component 3 by the cooling device 2.

[0015] With this configuration, the cooling system 1 performs an operation of cooling the heat-generating component 3 attached to the cooling device 2 based on the supply of the refrigerant 4 from the pump 5, and cooling the refrigerant 4 whose temperature has risen due to this cooling with the radiator 6. Therefore, the cooling system 1 enables the cooling device 2 to continuously cool the heat-generating component 3.

[0016] [Configuration of Cooling Device 2 and Pipe 7] Next, the details of the configuration of the cooling device 2 and the portion of the pipe 7 connected to the cooling device 2 according to the present embodiment will be described with reference to FIGS. 2 to 5. The broken lines shown in FIGS. 2 and 3 indicate the wall surfaces of the refrigerant flow paths in the upstream pipe 71 and the cooling device 2.

[0017] First, the configuration of the cooling device 2 will be described. As shown in FIG. 1, the cooling device 2 includes a cooler 10 to which the heat-generating component 3 is attached. The cooler 10 is formed of, for example, a metal or resin with excellent thermal conductivity. As shown in FIG. 4, the cooler 10 may be configured by joining a plurality of members 10a and 10b at arbitrary positions, or may be configured by a single member. For example, by forming the wall surface on which the heat-generating component 3 is arranged with an insulating material, insulation between the heat-generating component 3 and the refrigerant 4 is achieved.

[0018] In the cooler 10, the refrigerant inlet 12 is connected to the upstream pipe 71 located on the upstream side of the cooling device 2 in the pipe 7, and the refrigerant outlet 13 side is connected to the downstream pipe 72 located on the downstream side of the cooling device 2 in the pipe 7.

[0019] Hereinafter, the flow of the refrigerant 4 in the length direction of the refrigerant flow path 11 directed from the refrigerant inlet 12 side to the refrigerant outlet 13 side is referred to as main flow Fm, and the direction directed from the refrigerant inlet 12 side to the refrigerant outlet 13 side is referred to as "main flow direction DF". Further, among the walls constituting the cooler 10, the wall on the side where the heat-generating component 3 is mounted is referred to as "mounting wall 14", one surface of the mounting wall 14 on which the heat-generating component 3 is mounted is referred to as "mounting surface 15", and the one surface on the refrigerant flow path 11 side that is the opposite surface thereof is referred to as "cooling surface 16". Here, a partial member 10a of the cooler 10 constitutes the mounting wall 14. On the other hand, among the walls constituting the cooler 10, the wall facing the mounting wall 14 is referred to as "opposing wall 17", and the walls positioned between the mounting wall 14 and the opposing wall 17 are referred to as "side walls 18". Further, in the refrigerant flow path 11, the direction in which the both side walls 18 are arranged side by side is referred to as "width direction DW", and the direction in which the mounting wall 14 and the opposing wall 17 face each other is referred to as "height direction DH".

[0020] As shown in Figure 2, the cooler 10 has a refrigerant inlet portion 101 connected to the upstream pipe 71, and a cooling portion 102 located downstream of the refrigerant inlet portion 101 in the refrigerant flow and to which the heat-generating component 3 is attached.

[0021] The refrigerant inlet portion 101 is configured such that the cross section with the main flow direction DF as the normal direction is in the shape of a rectangular frame. As shown in Figure 2, the refrigerant inlet portion 101 has a shape in which the dimension in the width direction DW gradually expands along the main flow direction DF. For this reason, inside the refrigerant inlet portion 101, the dimension of the refrigerant flow path 11 in the width direction DW gradually increases along the main flow direction DF.

[0022] The cooling section 102 is the portion of the mounting wall 14 where the mounting surface 15 on which the heat-generating component 3 is mounted is located, and on the opposite side, where a cooling surface 16 that contacts the refrigerant 4 and cools the heat-generating component 3 is located. In the cooling section 102, the mounting wall 14 extends in a direction along the main flow direction DF, and one outer surface opposite to the inner wall surface that constitutes the refrigerant flow path 11 is a flat surface, and this flat surface is the mounting surface 15 on which the heat-generating component 3 is mounted. The cooling surface 16 also extends in a direction along the main flow direction DF. Furthermore, in the cooling section 102, the width dimension DW of the mounting wall 14 and the opposing wall 17 is kept constant. Therefore, in this embodiment, the cross-sectional area of ​​the refrigerant flow path 11 is approximately constant in the main flow direction DF.

[0023] In Figures 1 and 4, the cooling surface 16 is shown as a flat surface, but it is preferable that it is equipped with cooling fins or the like. Also, in this example, the mounting wall 14 and the opposing wall 17 extend along the main flow direction DF and the width dimension DW is constant, but they may be inclined with respect to the main flow direction DF, and the width dimension DW may also vary.

[0024] Next, we will explain the configuration of the upstream piping 71, which is located upstream of the cooling device 2 among the piping 7. As for the downstream piping 72, it is connected to the opposite side of the refrigerant inlet 101 of the cooling unit 102, and it is sufficient if the configuration does not obstruct the refrigerant flow as much as possible, so we will omit the explanation.

[0025] The upstream piping 71 is a part of the piping 7, specifically the portion of the piping 7 connected to the refrigerant inlet 101 of the cooler 10. In addition, it is equipped with a swirling flow forming section 73 that forms a swirling flow as a secondary flow of refrigerant 4 within the cooler 10. In this embodiment, the upstream piping 71 is composed of a connecting section 71a, a curved section 71b, and an inlet section 71c, and the swirling flow forming section 73 is formed by the shape of these pipes.

[0026] The connecting section 71a is the part that is connected to the cooler 10. The curved section 71b is located further away from the cooler 10 than the connecting section 71a, and is the part of the piping 7 that is curved from the inlet section 71c to the connecting section 71a. The inlet section 71c is located on the opposite side of the curved section 71b from the connecting section 71a, and is the part that guides the refrigerant 4 to the curved section 71b. The curved section 71b curves from the inlet section 71c, which extends from below, toward the connecting section 71a, that is, it curves toward the main flow direction DF from below, creating a curved structure for the internal refrigerant flow path, and is connected to the inlet section 71c below the connecting section 71a. As a result, the refrigerant 4 flowing through the inlet section 71c flows into the curved section 71b from below, and its flow direction is changed at the curved section 71b so that it flows toward the connecting section 71a. For convenience, the upstream piping 71 is referred to here as the connecting section 71a, the curved section 71b, and the inlet section 71c. However, in this embodiment, these are made up of a single component, and the parts are not made separately. The connecting section 71a can be any part of the upstream piping 71 that is connected to the cooling device 2, and one end of the curved section 71b may also be the connecting section 71a.

[0027] [Effects of Cooling System 1] As described above, in the cooling system 1 of this embodiment, the upstream pipe 71 located upstream of the cooling device 2 among the pipes 7 is provided with a swirling flow forming section 73 which consists of a connecting section 71a, a curved section 71b, and an inlet section 71c.

[0028] By providing such a swirling flow forming section 73, a secondary flow 30 can be generated in addition to the main flow Fm when the refrigerant 4 flows through the swirling flow forming section 73 in the upstream piping 71. In this embodiment, when the refrigerant 4 flows from the inlet section 71c to the connecting section 71a side via the curved section 71b, the flow direction of the refrigerant 4 is changed by the curved section 71b, and a secondary flow is generated in addition to the main flow Fm when the refrigerant 4 flows into the connecting section 71a. Specifically, when the refrigerant 4 passes through the curved section 71b, a centrifugal force corresponding to the curvature of the curved section 71b acts on it, generating a secondary flow 30 indicated by the arrow in Figure 5. When viewed from the main flow direction DF, this secondary flow 30 is formed on both sides of the center of the connecting section 71a, and on one side relative to the center of the connecting section 71a (left side of the paper), it becomes a counterclockwise swirling flow, and on the other side (right side of the paper), it becomes a clockwise swirling flow, resulting in a flow that flows in the main flow direction DF while swirling.

[0029] Furthermore, as this secondary flow 30 flows into the cooler 10, the secondary flow 30 continues within the refrigerant flow path 11, as shown in Figure 4. Since the secondary flow 30 is a counterclockwise or clockwise swirling flow, it acts to separate the refrigerant 4 near the cooling surface 16, which contributes to the cooling of the heat-generating component 3, from the cooling surface 16. Therefore, it becomes possible to increase the flow velocity of the refrigerant 4 at the cooling surface 16, thereby improving the cooling performance for the heat-generating component 3.

[0030] Furthermore, since the swirling flow forming section 73 is formed by the upstream piping 71 located upstream of the cooling device 2, it becomes possible to improve cooling performance regardless of the structure of the cooling device 2.

[0031] Furthermore, as mentioned above, Figures 1 and 4 show the cooling surface 16 as a flat surface, but it can also be equipped with cooling fins. In that case, it is preferable to generate a secondary flow 30 that matches the structure of the cooling fins. For example, a cooling fin with an uneven shape can be formed by creating an uneven surface on the cooling surface 16 or by joining fin members. The shape of the cooling fins is arbitrary, but for example, a chevron-type cooling fin can be formed, that is, a fin structure composed of V-shaped grooves that extend from the center of the width DW toward the side wall 18 along the length direction of the refrigerant flow path 11, from upstream to downstream of the refrigerant flow. In that case, by aligning the direction of the secondary flow 30 with the direction in which the cooling fins extend, it becomes possible to increase the flow velocity of the refrigerant 4 within the cooling fins, thereby improving the cooling performance.

[0032] (Second Embodiment) A second embodiment of this disclosure will now be described. This embodiment is a modification of the structure of the swirling flow forming section 73 compared to the first embodiment, and is otherwise the same as the first embodiment. Therefore, only the parts that differ from the first embodiment will be described.

[0033] As shown in Figures 6 and 7, in this embodiment, the swirling flow forming section 73 is constructed by making the curved section 71b of the upstream piping 71 meandering, and the inlet section 71c being located on the extension of the connecting section 71a. The dashed lines shown in Figures 6 and 7 indicate the walls of the refrigerant flow path in the upstream piping 71 and the cooling device 2.

[0034] In the first embodiment described above, the inlet portion 71c had a structure that extended from bottom to top. However, depending on the configuration of the cooling system 1, it may not be possible to make the inlet portion 71c have a shape that extends from bottom to top. For this reason, in this embodiment, the curved portion 71b is made serpentine, with the inlet portion 71c side of the curved portion 71b curving downwards, curving upwards as it approaches the connecting portion 71a side, and further curving towards the main flow direction DF on the connecting portion 71a side. In other words, within the curved portion 71b, there is a portion located below the connecting portion 71a, and it is structured to curve from that lower position toward the connecting portion 71a located above it, that is, from bottom toward the main flow direction DF.

[0035] In this way, by making the curved portion 71b meandering and providing a portion within the curved portion 71b that is located below the connecting portion 71a, a path can be formed for the refrigerant 4 to flow from below toward the connecting portion 71a. As a result, a secondary flow 30 similar to that of the first embodiment can be formed, and the cooling performance can be improved.

[0036] (Third embodiment) A third embodiment of this disclosure will now be described. This embodiment also modifies the structure of the swirling flow forming section 73 compared to the first embodiment, and is otherwise the same as the first embodiment, so only the parts that differ from the first embodiment will be described.

[0037] As shown in Figures 8 and 9, in this embodiment, the inner wall surface 71d of the refrigerant flow path in the upstream piping 71 is provided with a swirling flow forming section 73, which is formed by a protruding structure. The dashed lines shown in Figures 8 and 9 indicate the wall surface of the refrigerant flow path in the upstream piping 71 and the cooling device 2. Specifically, the swirling flow forming section 73 is formed on the inner wall surface 71d at the position on the mounting wall 14 side of the cooler 10 and at the position on the opposing wall 17 side, with a protruding structure that tapers towards the tip. The protruding structure is provided on the axis of symmetry of the inner wall surface 71d that constitutes the refrigerant flow path in the upstream piping 71, that is, with the center line in the width direction DW as the axis of symmetry, and protrudes in the height direction DH.

[0038] When the swirling flow forming section 73 is constructed with such a protruding structure, the refrigerant 4 flows along the shape of the swirling flow forming section 73 as it flows, generating a secondary flow 30. When viewed from the main flow direction DF, this secondary flow 30 is formed on both sides of the center of the upstream pipe 71, and on one side on the left side of the paper relative to the center of the upstream pipe 71, it becomes a clockwise swirling flow, while on the other side on the right side of the paper, it becomes a counterclockwise swirling flow, and the flow flows in the main flow direction DF while swirling.

[0039] Furthermore, since this secondary flow 30 flows into the cooler 10, it becomes possible to increase the flow velocity of the refrigerant 4 on the cooling surface 16, similar to the first embodiment, and thus improve the cooling performance for cooling the heat-generating components 3.

[0040] The length of the swirling flow forming section 73 in the main flow direction DF is arbitrary. That is, although Figure 9 shows the IX-IX cross section in Figure 8, the swirling flow forming section 73 formed by the protrusion structure may be formed only at the cross section shown in Figure 9, or it may be formed continuously downstream or upstream. However, the longer the length of the swirling flow forming section 73 in the main flow direction DF, the more stably the swirling flow of the secondary flow 30 can be generated, and the effect of improving cooling performance can be obtained more stably.

[0041] (Other embodiments) This disclosure is written in accordance with the embodiments described above, but is not limited to those embodiments and includes various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

[0042] In other words, the above embodiments are not unrelated to each other and can be combined as appropriate, except in cases where the combination is clearly impossible. Furthermore, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where they are explicitly stated to be particularly essential or where they are clearly considered essential in principle. Also, when numerical values ​​such as the number, numerical values, quantities, or ranges of the components of the embodiments are mentioned in the above embodiments, they are not limited to those specific numbers, except in cases where they are explicitly stated to be particularly essential or where they are clearly limited to a specific number in principle. Furthermore, when the shapes, positional relationships, etc., of the components, etc., are mentioned in the above embodiments, they are not limited to those shapes, positional relationships, etc., except in cases where they are explicitly stated to be particular or where they are clearly limited to a specific shape, positional relationship, etc., in principle.

[0043] For example, the swirling flow forming section 73 can have a structure that includes the curved section 71b structure shown in the first and second embodiments, as well as a protruding structure like that of the third embodiment.

[0044] Furthermore, while the first and second embodiments described above show an example of the configuration of the curved portion 71b, other structures are also acceptable as long as they can generate a secondary flow 30 that becomes a swirling flow and increase the flow velocity of the refrigerant 4 at the cooling surface 16.

[0045] Furthermore, in each of the above embodiments, when the upstream piping 71 is cut in a cross-section where the tangential direction of the main flow Fm of the refrigerant 4 is the normal direction, the refrigerant flow path is a circular flow path with a circular shape for the inner wall surface 71d. However, this is merely one example, and the cross-sectional shape of the refrigerant flow path may be an ellipse, a rectangle, or other shape.

[0046] Furthermore, in each of the above embodiments, a structure was shown in which the cross-sectional area of ​​the refrigerant flow path 11 within the cooling unit 102 is the same. However, this is merely one example, and other structures may be used, such as a structure in which the refrigerant flow path 11 gradually narrows from the refrigerant inlet 12 side to the refrigerant outlet 13 side. [Explanation of Symbols]

[0047] 1...Cooling system, 2...Cooling device, 3...Heat-generating component, 4...Refrigerant, 5...Pump, 6...Heat sink, 7...Piping, 10...Cooler, 10a...Component, 10b...Component, 11...Refrigerant flow path, 12...Refrigerant inlet, 13...Refrigerant outlet, 14...Mounting wall, 15...Mounting surface, 16...Cooling surface, 17...Opposite wall, 18...Side wall, 71...Upstream piping, 71a...Connection section, 71b...Bend section, 71c...Inlet section, 71d...Inner wall surface, 72...Downstream piping, 73...Swirl flow forming section, 101...Refrigerant inlet section, 102...Cooling section, DF...Main flow direction, DH...Height direction, DW...Width direction, Fm...Main flow

Claims

1. A cooling system for cooling a heat-generating component (3), A pipe (7) through which the refrigerant (4) flows, The cooling device (1) includes a cooler (10) connected to the aforementioned piping and having a refrigerant flow path (11) through which the refrigerant flowing from the aforementioned piping flows, A cooling system in which the upstream pipe (71) of the aforementioned piping, which is connected to the upstream side of the cooling device, is provided with a swirling flow forming unit (73) that generates a secondary flow (30) which becomes a swirling flow, thereby transmitting the swirling flow into the refrigerant flow path in the cooler.

2. The cooler includes a mounting wall (14) on which the heat-generating component is mounted, and one side of the mounting wall on the refrigerant flow path side is a cooling surface (16) that cools the heat-generating component by exchanging heat with the refrigerant. The cooling system according to claim 1, wherein the cooling surface is provided with cooling fins, and the swirling flow forming section generates the secondary flow in accordance with the structure of the cooling fins.

3. The upstream piping includes a connecting portion (71a) connected to the cooling device, a curved portion (71b) upstream of the connecting portion and connected to the connecting portion, and an inlet portion (71c) located on the opposite side of the curved portion from the connecting portion (71a) and guiding the refrigerant to the curved portion. The cooling system according to claim 1 or 2, wherein the curved portion is curved between the inlet portion and the connecting portion, and the secondary flow is generated by making the refrigerant flow path formed inside a curved structure.

4. The cooling system according to claim 1 or 2, wherein the swirling flow forming section is a projection structure formed on the axis of symmetry of the inner wall surface constituting the refrigerant flow path within the upstream piping.

5. The cooling system according to claim 4, wherein the projection structure tapers towards the tip.

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