JP2015179801A - Cooling system and electronic apparatus mounted therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system capable of improving workability of mounting/dismounting work accompanying repeated maintenance works and preventing reduction of cooling performance.SOLUTION: The cooling system includes: a first heat exchanger 6 which is disposed at the electronic apparatus housing side; and a second heat exchanger 7 which is disposed at the housing side, and the first heat exchanger 6 and the second heat exchanger 7 are independent from each other. With this, repeated mounting/dismounting work accompanying maintenance work can be carried out easily. An inclined first heat radiation surface and an inclined second heat receiving surface are thermally connected to each other. With this, the repeated mounting/dismounting work can be carried out easily while ensuring the cooling performance.

Description

  The present invention relates to, for example, a cooling device for an electronic component on which a power semiconductor element is mounted, and an electronic device on which the cooling device is mounted.

  2. Description of the Related Art Conventionally, in an electronic device such as a computer equipped with a power semiconductor element such as a CPU or IGBT, the amount of heat generated by the power semiconductor element has increased as the amount of information, processing speed, and output have increased.

  Excessive heat generation in the power semiconductor element can cause deterioration in performance of the power semiconductor element and damage of the power semiconductor element.

  Therefore, an electronic device such as a computer using a power semiconductor element includes a cooling device in order to bring the power semiconductor element to an optimum temperature state.

  Also, electronic equipment storage boxes (for example, server modules mounted on blade servers) that contain power semiconductor elements and other electronic components are used for the purpose of meeting increasing needs for information volume, processing speed, and output, and for maintenance purposes. It is designed to be mounted repeatedly and detachably.

  As a cooling device for cooling the heat generated by such a power semiconductor element, a boiling cooling device described in Patent Document 1 is known.

  This boiling cooling device uses the principle of a thermosyphon. A heat receiving part that stores liquid refrigerant inside and receives the heat of the power semiconductor element, and a heat receiving part that is placed above the heat receiving part and radiates heat by forced air cooling by a blower. It has a heat radiating part to perform and cools by the action of the phase change of the refrigerant.

  The cooling device to which the power semiconductor element is attached is arranged in an electronic device storage box like other electronic components, and a plurality of electronic device storage boxes are housed in a robust housing. It has become.

  In such a configuration, since the cooling device cannot easily separate the heat receiving portion and the heat radiating portion, the electronic device storage box including the cooling device is taken out from the housing during maintenance of the electronic device storage box.

  The heat dissipating part of the conventional boil cooling device that dissipates heat by forced air cooling is a plate fin type heat exchanger having a refrigerant flow path inside, and is larger than the heat receiving part. For this reason, consideration has not been given to the fact that the size of the electronic device storage box is increased, and the attachment / detachment work of the electronic device storage box associated with maintenance is not taken into account. It was.

  The cooling device described in Patent Document 2 is known for the above problems. The cooling device includes a first heat exchanger that has a first circulation path for circulating the refrigerant and performs cooling by forced water flow, and a second circulation path that is independent of the first heat exchanger. It is the structure provided with the 2nd heat exchanger which cools with the effect | action of a heat pipe.

  Here, the second heat exchanger receives the heat of the power semiconductor element at the heat receiving portion disposed in the second circulation path, and then supplies the refrigerant heated by the heat receiving portion to the heat radiating portion. I am doing so.

  And it has the structure which connected to the thermal radiation part of this 2nd heat exchanger in the state which can be heat-exchanged and attached or detached with the heat receiving part arrange | positioned in the 1st circulation path of the 1st heat exchanger. .

  The second heat exchanger is disposed in an electronic device storage box that can be attached to and detached from the housing, and the first heat exchanger is disposed on the housing side.

  With such a configuration, the refrigerant circulating in the second circulation path of the second heat exchanger can be cooled by the refrigerant circulating in the first circulation path of the first heat exchanger. Thus, since the first heat exchanger performs cooling with a forced water flow having a cooling efficiency better than that of forced air cooling, the heat radiating portion and the electronic device storage box of the second heat exchanger can be reduced in size.

  Thereby, at the time of the maintenance of the power semiconductor element, the electronic device in which the second heat exchanger is accommodated by detaching the thermal connection between the heat receiving portion of the first heat exchanger and the heat radiating portion of the second heat exchanger. The storage box can be attached and detached, and the problem of the complexity of attaching and detaching the electronic device storage box accompanying maintenance is reduced.

  However, in the configuration of Patent Document 2, the connection between the heat receiving portion of the first heat exchanger and the heat radiating portion of the second heat exchanger is attached and detached in the electronic device storage box every time maintenance work is performed on the electronic device storage box. However, there is a concern that it will be difficult to work in a blade server with high-density mounting of electronic components, because it is not considered for mounting and dismounting in an electronic device storage box in which multiple electronic devices are mounted. There is.

  In addition, there is a problem that the adhesion of the heat receiving part of the first heat exchanger and the heat radiating part of the second heat exchanger is impaired during the attachment / detachment work. No consideration is given to the positioning of the heat exchanger 2 with respect to the heat radiating part.

JP-A-8-204075 JP 2005-79483 A

  The present invention solves the above-described problems, and even when the electronic device storage box is repeatedly attached and detached during maintenance, the heat receiving portion of the first heat exchanger and the heat dissipation of the second heat exchanger are performed. An object of the present invention is to provide a cooling device that can be attached and detached reliably at a predetermined position without impairing the adhesion with the part, improve the maintainability, and realize downsizing of the electronic device storage box. Is.

  Therefore, in order to achieve this object, the electronic device according to the present invention includes a plurality of electronic device storage boxes in the casing, and a first refrigerant serving as a working fluid is contained inside the electronic device storage box. A first heat receiving portion that receives heat from the power semiconductor element that is enclosed and serves as a heating element, a first heat radiating portion that releases heat of the first refrigerant, a first heat receiving portion, and a first heat radiating portion; A first heat exchanger is formed by forming a first circulation path by a pipe line connecting the inside, a blower and a second refrigerant as a working fluid are enclosed inside the housing, A second heat receiving portion that receives heat from the first heat radiating portion, a second heat radiating portion that releases heat of the second refrigerant by heat exchange with the outside air sent by the blower, a second heat receiving portion, and a second heat receiving portion. A second heat exchanger is formed by forming a second circulation path with a pipe line connecting the heat radiation part of In the first heat radiating surface in contact with the second heat receiving portion, the first heat radiating portion is provided with a convex portion on the first heat radiating surface, and the second heat receiving portion rides on the convex portion. The part and the second heat receiving part come into contact with each other.

  The initial object is achieved by the cooling device configured as described above.

  As described above, according to the present invention, the first heat radiating portion is provided with a convex portion, and the convex portion is brought into contact with the second heat receiving portion so that it can be repeatedly attached and detached along with the maintenance of the electronic device storage box. Even if it performs, since a 1st thermal radiation part and a 2nd heat receiving part can be reliably connected in a predetermined position, the adhesiveness is not impaired and the fall of cooling performance can be prevented.

Schematic installation of an electronic device equipped with the cooling device of Embodiment 1 of the present invention Schematic cross-section of the electronic device and cooling device Detailed schematic diagram of the connection between the first heat exchanger and the second heat exchanger of the cooling device Diagram showing maintenance of the cooling system

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an installation schematic diagram of the electronic device and the cooling device 5 of the present embodiment, and FIG. 2 shows a schematic sectional view thereof.

  Inside the casing 1 of the electronic device, two electronic device storage boxes 3 are arranged in the vertical direction. The housing 1 is attached so that the door 2 can be opened and closed in the door opening and closing direction t indicated by a broken arrow.

  The electronic device storage box 3 includes a plurality of electronic components for performing large-capacity data processing and power conversion, and the power semiconductor element 4 (for example, IGBT, MOSFET) generates heat in particular. It is. In order to efficiently cool the power semiconductor element 4, a cooling device 5 is provided, and the cooling device 5 is arranged to communicate the top surface and the inside of the housing 1.

  In the present embodiment, one cooling device 5 is arranged for one electronic device storage box 3. Therefore, as shown in FIG. 2, in the present embodiment, two electronic device storage boxes are provided in the upper and lower sides in one housing, and therefore one cooling device 5 is arranged for each.

  The cooling device 5 includes a first heat exchanger 6 and a second heat exchanger 7 that are thermally connected to each other by an independent closed system.

  2 and 3 are detailed schematic views of the first heat exchanger 6 and the second heat exchanger 7 and their connecting portions.

  The first heat exchanger 6 includes a first refrigerant 8 (for example, pure water, alcohol, or a chlorofluorocarbon refrigerant) serving as a working fluid inside, and includes a first heat receiving unit 9 and a first heat radiating unit. A circulation path is formed by the first vapor pipe 11 and the first liquid pipe 12 that are connected in an airtight manner, and a check valve 13 is connected to a connection portion between the first heat receiving section 9 and the first liquid pipe 12. It is the composition provided with.

  The first heat receiving unit 9 is disposed at the bottom of the electronic device storage box 3, and three power semiconductor elements 4 are attached to the lower surface.

  In consideration of thermal connection, for example, heat conductive grease or a heat conductive sheet is sandwiched between the contact surface with the power semiconductor element 4 to reduce the contact thermal resistance. A first vapor pipe 11 and a first liquid pipe 12 are arranged on the upper surface of the first heat receiving unit 9 with a predetermined distance therebetween.

  Further, here, in the first heat receiving section 9, a liquid supply pipe 28 that supplies the liquid first refrigerant 8 is disposed between the heat receiving surface 27 that is directly above the power semiconductor element 4 and the check valve 13. In addition, a slight gap is provided between the liquid supply pipe 28 and the heat receiving surface 27.

  The first heat radiating unit 10 is arranged in the electronic device storage box 3 on the back side when viewed from the door 2 of the housing 1. A first steam pipe 11 is connected to the upper part of the first heat radiating part 10, and a first liquid pipe 12 is connected to the lower part of the first heat radiating part 10.

  The first heat radiating portion 10 is connected to the second heat exchanger 7 at the first heat radiating surface 14, and a convex portion 15 is provided below the first heat radiating surface 14. The first heat radiating surface 14 is inclined in a direction that forms an obtuse angle with respect to the protruding portion 15 and the protruding direction.

  The second heat exchanger 7 has a second refrigerant 16 (for example, pure water, alcohol, or a chlorofluorocarbon refrigerant) serving as a working fluid enclosed therein, and a second heat receiving portion 17 and a second heat radiating portion. A circulation path is formed by the second vapor pipe 19 and the second liquid pipe 20 which are connected in an airtight manner.

  One end of the second steam pipe 19 is connected to the upper part of the second heat receiving part 17, and one end of the second liquid pipe 20 is connected to the lower part of the second heat receiving part 17.

  The other end of the second vapor pipe 19 is connected to the upper part of the second heat radiating part 18, and the other end of the second liquid pipe 20 is connected to the lower part of the second heat radiating part 18.

  The second heat receiving unit 17 is disposed in the housing 1 on the back side when viewed from the door 2, and on the second heat receiving surface 21 on the back side of the electronic device storage box 3, the first heat radiating unit 10. In contact with. Between the second heat receiving surface 21 and the first heat radiating surface 14, for example, heat conductive grease or a heat conductive sheet is sandwiched between the contact surface with the power semiconductor element 4 in consideration of the thermal connection. The resistance is reduced.

  A recess 23 is provided in the lower part of the second heat receiving surface 21, and the second heat receiving surface 21 is inclined in a direction that forms an obtuse angle with respect to the retracting direction of the recess 23.

  The second heat radiating unit 18 is disposed on the top surface of the housing 1, and includes a blower 22 on the back side when viewed from the door 2 on the top surface of the housing 1, and a grill 29 on the door 2 side. The blower 22 blows outside air from the door 2 side to the back side. That is, the grill 29, the second heat radiating portion 18, and the blower 22 are arranged in this order from the windward side.

  In the present embodiment, among the two electronic device storage boxes 3, the second heat radiating portion 18 corresponding to the cooling device 5 of the lower electronic device storage box 3 is arranged side by side so as to be closer to the windward side. ing.

  This is because, in the two cooling devices 5, the circulation path corresponding to the lower electronic device storage box 3 becomes longer, which is disadvantageous for the cooling performance, so that the performance difference is alleviated.

  Next, the operation of each heat exchanger and the circulation of the refrigerant will be described.

  First, in the first heat exchanger 6, the heat generated by the power semiconductor element 4 is received by the first heat receiving unit 9. That is, the liquid-phase first refrigerant 8 boils inside the first heat receiving portion 9 and absorbs the heat of the power semiconductor element 4 by the action of the phase change.

  Then, the first refrigerant 8 in the gas phase moves only to the first heat radiating unit 10 through the first steam pipe 11 by the action of the check valve 13.

  Here, the first refrigerant 8 is in contact with the first heat transfer promoting body 24 (for example, trapezoidal parallel plate fins) in the first heat radiating section 10 to exchange heat, and from the gas phase to the liquid phase again. The phase changes to. Thereafter, the first refrigerant 8 circulates again through the first liquid pipe 12 to the first heat receiving unit 9 by the action of gravity.

  The action of the check valve 13 is that the first refrigerant 8 opens in the direction in which the first refrigerant 8 flows from the first liquid pipe 12 to the first heat receiving unit 9 but does not open in the opposite direction. In the heat exchanger 6, the circulation direction of the refrigerant can be uniquely determined.

  Further, a large flow velocity is generated when the gas-phase first refrigerant 8 that has undergone a phase change due to heat generation of the power semiconductor element 4 passes through a slight gap provided between the liquid supply pipe 28 and the heat receiving surface 27. Since the cooling efficiency at the heat receiving surface 27 is improved with this large flow velocity, the present invention is particularly effective for cooling although the high heat generating portion is unevenly distributed inside the power semiconductor element 4.

  Next, in the second heat exchanger 7, the first heat exchanger 6 is cooled by the second heat receiving portion 17 thermally connected to the first heat radiating portion 10. In other words, the liquid second refrigerant 16 boils in contact with the second heat transfer promoting body 25 (for example, trapezoidal parallel plate fins) inside the second heat receiving portion 17, and due to the effect of the phase change. The heat of the first heat radiating part 10 is absorbed.

  The gas-phase second refrigerant 16 moves to the second heat radiating section 18 through the second vapor pipe 19 due to the density difference and the pressure difference, and indirectly exchanges heat with the outside air by the blower 22. And the phase changes from the gas phase to the liquid phase again.

  Thereafter, the second refrigerant 16 circulates again through the second liquid pipe 20 to the second heat receiving portion 17 by the action of gravity.

  Here, it supplements about the natural circulation of the refrigerant | coolant in the inside of the 2nd heat exchanger 7 which is a closed circuit circulation path independently.

  The gas phase second refrigerant 16 that has boiled in the second heat receiving unit 17 due to the heat of the first heat radiating unit 10 and has undergone a phase change passes through the second liquid pipe 20 from the lower part of the second heat receiving unit 17. Since the density is lower than that of the supplied second refrigerant 16 in the liquid phase, it moves upward in the second heat receiving portion 17.

  Further, since the pressure in the second heat radiating portion 18 cooled by the outside air is lower than that in the second heat receiving portion 17 that absorbs the heat of the first heat radiating portion 10, The second refrigerant 16 moves to the second heat radiating portion 18 through the vapor pipe 19.

  Due to the above-described configuration and refrigerant circulation, the heat generated by the power semiconductor element 4 is efficiently absorbed by the first heat exchanger 6 and is transferred by heat to the outside of the electronic device storage box 3, so that the second heat The heat is radiated out of the housing 1 by the exchanger 7.

  Next, maintenance work of the electronic device storage box 3 which is particularly important in the present embodiment will be described with reference to FIG.

  In the electronic device shown in the present embodiment, when maintenance work of an electronic component occurs, the electronic device storage box 3 needs to open the door 2 and take it out of the housing 1 from the door 2 side.

  At this time, in the present embodiment, the inspection port 26 is provided at the same position as the second heat receiving portion 17 on the back side of the housing 1. At the time of maintenance work, first, the attachment / detachment work between the first heat radiating unit 10 and the second heat receiving unit 17 is performed from the inspection port 26.

  That is, the attachment / detachment of the first heat radiating part 10 and the second heat receiving part 17 is provided in the second heat receiving part 17 by, for example, a female screw part (not shown) provided on the first heat radiating part 10 side. A structure that can be attached and detached by using a fastening bolt through a bolt insertion hole (not shown). The fastening bolt is tightened from the inspection port 26, and the electronic device storage box 3 is then moved along a slide rail (not shown) installed between the housing 1 and a maintenance direction s indicated by a broken arrow. Pull it out to the door 2 side.

  Thus, by using two heat exchangers that form a closed circuit, the electronic device storage box 3 can be attached and detached without cutting the circuit.

  In this attachment / detachment operation, particularly when the electronic device storage box 3 is installed in the housing 1, the convex portion 15 of the first heat radiating portion 10 and the concave portion 23 of the second heat receiving portion 17 are aligned at the initial design position. Since the contact can be ensured, the cooling capacity can be maintained and the electronic device and the cooling device 5 can be prevented from being damaged.

  Further, by combining the convex portion 15 and the concave portion 23, the second heat receiving portion 17 is in contact with the first heat radiating surface 14 and the second heat receiving surface 21 in an inclined state while riding on the first heat radiating portion 10. Therefore, due to the fastening force of the fastening bolt and the action of gravity, it is possible to maintain the adhesiveness of the connection between the first heat radiating surface 14 and the second heat receiving surface 21 and to reduce the number of fastening bolts, and to attach and detach more. The workability of the work can be improved.

  Moreover, as shown in FIG. 3, the 2nd heat receiving surface 21 is made to incline, and the facing is made into the perpendicular | vertical. Thereby, the 2nd heat receiving part 17 becomes a shape from which a volume becomes large gradually from the lower part to the upper part. As described above, in the second heat exchanger 7, the second refrigerant 16 naturally circulates due to the pressure difference. Therefore, when the volume of the upper portion of the second heat receiving portion 17 is increased, the pressure loss is reduced. It becomes easy to obtain the effect of the pressure difference.

  The upper surface of the first heat radiating unit 10 and the upper surface of the second heat transfer promoting body 25 are in the same position, and the upper surface of the second heat receiving unit 17 is higher than the upper surface of the first heat radiating unit 10. Yes. With this configuration, it is possible to secure a space where the second refrigerant 16 in a gas phase can be stored without being subjected to heat exchange in the upper part of the second heat receiving unit 17.

  The gas-phase refrigerant cannot undergo any further phase change, and if it is heat-exchanged, there is a concern that it will become superheated steam and further partially dry out. The refrigerant 16 can be allowed to flow into the second steam pipe 19 without being subjected to heat exchange, and a decrease in cooling performance can be prevented.

  In the present embodiment, the first heat transfer promoting body 24 is a substantially trapezoidal parallel plate fin. This is a shape in which, for example, a plurality of smooth surfaces having a fin thickness of 0.3 mm to 3 mm are arranged in parallel at a fin pitch of 0.8 mm to 8 mm.

  The fin surface may be subjected to a hydrophobic surface treatment (for example, fluorine coating). In this case, the second refrigerant 16 condensed on the fin surface is likely to sag, and the fin surface is covered with the condensed film refrigerant. It is easy to secure an effective heat transfer surface.

  The shape of the first heat transfer promoting body 24 may be a needle-like protrusion. In this case, the first heat transfer-promoting body 24 is shaped like a needle-like protrusion from the bottom to the top in accordance with the shape in the first heat radiating portion 10. The length of the heat promoting body 24 is gradually shortened.

  Further, in the present embodiment, the second heat transfer promoting body 25 is a parallel plate fin. This is a shape in which, for example, a plurality of smooth surfaces having a fin thickness of 0.3 mm to 3 mm are arranged in parallel at a fin pitch of 0.8 mm to 8 mm.

  The fin may be subjected to a new aqueous surface treatment (for example, blasting). In this case, generation and separation of bubble nuclei due to boiling on the fin can be promoted, and cooling performance can be improved. .

  Further, the shape of the second heat transfer promoting body 25 may be a narrow groove, a needle-like protrusion, or a metal wick. If it is a metal wick, the surface of the second heat transfer promoting body 25 is not subjected to surface treatment. In both cases, an increase in surface area and generation of bubble nuclei and promotion of separation can be realized.

  In addition, since the radiator using the corrugated fin can be used for the 2nd thermal radiation part 18, for example, since a big heat-transfer area can be obtained with respect to a volume, high cooling performance can be obtained.

  A part of the second vapor pipe 19 and the second liquid pipe 20 may be a rubber hose. In this case, the installation position of the electronic device storage box 3 and the first heat exchanger 6 is the manufacturing and maintenance. Even if the initial design position cannot be maintained at this time, the connection position of the second heat receiving unit 17 with respect to the first heat radiating unit 10 can be corrected.

  The inspection port 26 has a lid that can be opened and closed only during maintenance.

  As described above, the present invention includes two independent heat exchangers provided on the housing side and the electronic device storage box side, thereby facilitating repeated attachment / detachment work associated with maintenance, and the inclined first heat radiation surface. As a cooling device for various electronic devices, it is a cooling device that makes it easy to repeatedly attach and detach work and ensure cooling performance by the configuration in which the first and second heat receiving surfaces are thermally connected. Be utilized.

DESCRIPTION OF SYMBOLS 1 Housing | casing 2 Door 3 Electronic equipment storage box 4 Power semiconductor element 5 Cooling device 6 1st heat exchanger 7 2nd heat exchanger 8 1st refrigerant | coolant 9 1st heat receiving part 10 1st thermal radiation part 11 1st 1 steam pipe 12 first liquid pipe 13 check valve 14 first heat radiation surface 15 convex part 16 second refrigerant 17 second heat receiving part 18 second heat radiation part 19 second steam pipe 20 second Liquid pipe 21 Second heat receiving surface 22 Blower 23 Recess 24 First heat transfer promoting body 25 Second heat transfer promoting body 26 Inspection port 27 Heat receiving surface 28 Liquid supply pipe 29 Grill t Door opening / closing direction s Maintenance direction

Claims (11)

Regarding electronic components that generate heat during operation such as power semiconductor elements,
A plurality of electronic device storage boxes are provided in the housing,
In the electronic device storage box,
A first refrigerant to be a working fluid is enclosed inside,
A first heat receiving portion that receives heat from the power semiconductor element serving as a heating element;
A first heat dissipating part that releases heat of the first refrigerant;
A first heat exchanger configured by forming a first circulation path by a pipe line connecting the first heat receiving section and the first heat radiation section;
In the housing, a blower,
A second refrigerant to be a working fluid is enclosed inside,
A second heat receiving portion that receives heat from the first heat radiating portion;
A second heat dissipating part that releases heat of the second refrigerant by heat exchange with outside air sent by the blower;
A second heat exchanger configured by forming a second circulation path with a pipe line connecting the second heat receiving part and the second heat radiating part;
In the first heat dissipating surface where the first heat dissipating part comes into contact with the second heat receiving part,
A cooling device for an electronic device, wherein a convex portion is provided on the first heat radiating surface, and the first heat radiating portion and the second heat receiving portion are in contact with each other in a state where the second heat receiving portion rides on the convex portion. The first heat dissipating part is disposed on the inner wall surface of the electronic device storage box,
The convex portion protrudes toward the outside of the electronic device storage box,
The cooling device according to claim 1, wherein the first heat radiating surface is inclined at an obtuse angle with respect to the protruding direction of the convex portion. The cooling device according to claim 1 or 2, wherein a plurality of first heat transfer promoting bodies are provided in the first heat radiation portion. Arranging a second heat receiving portion on the inner wall surface of the housing;
In the second heat receiving surface where the second heat receiving portion is in contact with the first heat radiating portion,
A recess is provided at a lower portion of the second heat receiving surface;
The cooling device according to any one of claims 1 to 3, wherein the second heat receiving surface is inclined at an obtuse angle with respect to a drawing direction of the recess. The cooling device according to any one of claims 1 to 4, wherein a plurality of second heat transfer promoting bodies are provided in the second heat receiving portion. The cooling device according to claim 1, wherein the housing is provided with an inspection port. The cooling device according to claim 3, wherein the first heat transfer promoting body is a trapezoidal flat plate fin. The cooling device according to claim 3, wherein the first heat transfer promoting body is a needle-like protrusion. The cooling device according to claim 5, wherein the second heat transfer promoting body is a trapezoidal flat plate fin. The cooling device according to claim 5, wherein the second heat transfer promoting body is a needle-like protrusion. The cooling device according to claim 5, wherein the second heat transfer promoting body is formed of a metal wick.

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