JP2013100955A - Heat exchanger, method for manufacturing the same, air conditioner, and information processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a heat exchanging ratio in a heat exchanger in the heat exchanger, a method for manufacturing the same, an air conditioner and an information processing system.SOLUTION: The heat exchanger 12 includes: a refrigerant pipe 31; a plurality of first fins 32 which are attached to the refrigerant pipe 31 to be spaced from the first fins and are exposed to an air flow A; and a second fin 33 which is attached to the refrigerant pipe 31 between the neighboring first fins 32 and twisted by using a direction D2 along the air flow A as a twist center axis.

Description

  The present invention relates to a heat exchanger, a manufacturing method thereof, an air conditioner, and an information processing system.

  With the development of information technology in recent years, the amount of data handled in a data center has increased, and along with this, more computers are being installed in server racks in the data center. As a result, it is said that the air conditioner installed in the data center consumes a large amount of power comparable to the total power consumed by all the computers.

  The air conditioner is provided with a heat exchanger for cooling the air heated in the data center by heat exchange with cooling water. In order to reduce the power consumption of the air conditioner, it is preferable to improve the heat exchange efficiency in the heat exchanger.

JP-A-8-313176 JP-A-60-120191 Japanese Utility Model Publication No. 3-70599

  In a heat exchanger and its manufacturing method, an air conditioner, and an information processing system, it aims at improving the heat exchange efficiency of a heat exchanger.

  According to one aspect of the following disclosure, a refrigerant pipe, a plurality of first fins that are attached to the refrigerant pipe at intervals and exposed to an air flow, and the gap between the adjacent first fins There is provided a heat exchanger having a second fin attached to a refrigerant pipe and twisted with the direction along the air flow as a central axis of twist.

  According to another aspect of the disclosure, the step of forming a pipe portion protruding from the main surface of the metal plate by drilling the metal plate, and the twisting shape by twisting the metal plate A step of producing a given fin; a step of inserting a refrigerant pipe into the pipe portion; and supplying the air having a pressure higher than the atmospheric pressure into the refrigerant pipe to expand the refrigerant pipe, and The manufacturing method of the heat exchanger which has the process of crimping | bonding the inner surface of a part and the outer peripheral side surface of the said refrigerant | coolant piping is provided.

  According to the following disclosure, the air flow is disturbed by the twisted second fin, and at the same time, the combined surface area of the first and second fins can be increased, thereby increasing the heat exchange efficiency of the heat exchanger. Can do.

FIG. 1 is a schematic diagram of an information processing system according to the first embodiment. FIG. 2 is a partially exploded perspective view of the heat exchanger according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of the heat exchanger according to the first embodiment viewed from the upstream side of the air flow. FIG. 4 is a graph obtained by simulating how the pressure loss of the heat exchanger changes according to the total surface area of the first fin and the second fin in the first embodiment. Fig.5 (a) is a top view in the middle of manufacture of the 2nd fin which concerns on 1st Embodiment (the 1), FIG.5 (b) is sectional drawing which follows the II line | wire of Fig.5 (a) It is. FIG. 6A is a top view (part 2) in the middle of manufacturing the second fin according to the first embodiment, and FIG. 6B is a side view thereof. Drawing 7 is a perspective view in the middle of manufacture of the heat exchanger concerning a 1st embodiment. FIG. 8: is a side view (the 1) in the middle of manufacture of the heat exchanger which concerns on 1st Embodiment. FIG. 9 is a side view (part 2) of the heat exchanger according to the first embodiment during manufacture. FIG. 10 is an enlarged cross-sectional view of the refrigerant pipe and its surroundings during the manufacture of the heat exchanger according to the first embodiment. FIG. 11A is a top view (part 1) of the second fin according to the second embodiment during manufacture, and FIG. 11B is a cross-sectional view taken along the line II-II in FIG. It is. FIG. 12A is a top view (part 2) in the middle of manufacturing the second fin according to the second embodiment, and FIG. 12B is a side view thereof. FIG. 13 is a partially exploded perspective view of the heat exchanger according to the second embodiment.

  Embodiments will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a schematic diagram of an information processing system according to the present embodiment.

  The information processing system 1 is used in a data center 17 such as an Internet data center (IDC), and includes an air conditioner 10 and a server rack 20.

  Among these, the air conditioner 10 includes a heat exchanger 12, a housing 13, and a fan unit 24. The heat exchanger 12 and the fan unit 14 are both housed in the housing 13 and are used to cool the air in the data center 17.

  A forward water line 23 and a return water line 24 are connected to the heat exchanger 12. The outgoing water line 23 and the return water line 24 are connected to the chiller 22, and the cooling water generated by the chiller 22 is supplied to the heat exchanger 12 through the outgoing water line 23. Then, the cooling water warmed by the heat exchanger 12 returns to the chiller 22 through the return water line 24 and is cooled in the chiller 22.

  The fan unit 14 includes a plurality of fans 15 for generating the air flow A.

  The air flow A is supplied to the server rack 20 through the cold aisle 19 partitioned in the data center 17.

  The server rack 20 is provided in a device installation area 18 partitioned in the data center 17 and includes a plurality of computers 21 such as servers for performing information processing. The computer 21 is an example of an information processing device.

  Each computer 21 is provided with a heat generating component (not shown) such as a CPU (Central Processing Unit), and the heat generating component is cooled by the air flow A taken in from the intake surface 21 a of each computer 21. Then, the air flow A heated by the heat generating components is exhausted into the data center 17 from the exhaust surface 21 b side of each computer 21 and then cooled again in the air conditioner 10.

  FIG. 2 is a partially exploded perspective view of the heat exchanger 12.

  As shown in FIG. 2, the heat exchanger 12 includes a plurality of refrigerant pipes 31, first fins 32, and second fins 33.

  Among these, the 1st fin 32 is a flat metal plate exposed to the air flow A to be cooled, and is mechanically attached to the refrigerant pipe 31. Although the material of the first fin 32 is not particularly limited, in order to efficiently exchange heat with the air flow A, a metal plate made of a metal having good thermal conductivity such as aluminum or copper is used as the first metal plate. The fins 32 are preferably used.

  A plurality of such first fins 32 are provided at intervals along the extending direction D 1 of the refrigerant pipe 31, and a flow path of the air flow A is defined between the adjacent first fins 32. .

  The extending direction D1 of the refrigerant pipe 31 is orthogonal to the direction D2 along the air flow A. This type of heat exchanger is also called a cross-flow type gas-liquid heat exchanger.

  In the present embodiment, the interval P1 between the adjacent first fins 32 is about 3 mm.

  The interval P2 between the refrigerant pipes 31 adjacent in the horizontal direction is about 40 mm, and the interval P3 between the refrigerant pipes 31 adjacent in the vertical direction is about 30 mm.

  The coolant pipe 31 is supplied with cooling water flowing through the above-described outbound water line 23, whereby the first fins 32 and the second fins 33 are cooled. The material of the refrigerant pipe 31 is not particularly limited, but it is preferable to use a metal pipe made of a metal such as copper or aluminum as the refrigerant pipe 31 as in the first fin 32.

  On the other hand, the second fin 33 is attached to the refrigerant pipe 31 between the adjacent first fins 32 and is twisted about the direction D2 along the flow path of the air flow A as the central axis. In addition, as a material of the 2nd fin 33, metals, such as the above-mentioned copper and aluminum, can be employ | adopted.

  The second fins 33 adjacent to each other in the direction D3 orthogonal to both the direction D1 and the direction D2 are separated by the same distance as the distance P3. Overcrowding is prevented.

  In the absence of the second fin 33, the air flow A becomes a laminar flow along the first fin 32, and the air flow A is not disturbed, so the heat exchange rate of the heat exchanger 12 is reduced. By twisting the second fin 33, the air flow A is appropriately disturbed, and the heat exchange rate is improved. Furthermore, by twisting the second fins 33 in this way, the combined surface area of the first fins 32 and the second fins 33 is increased, which also improves the heat exchange rate.

  In particular, by twisting the second fin 33 about the direction D2 along the flow path of the air flow A as a central axis, the air flow A can be appropriately rotated without obstructing the flow of the air flow A in the direction D2. It is possible to increase the heat exchange efficiency of the heat exchanger 12 while ensuring the ease of passage of the air flow A.

  Further, the ease of passing the airflow A can be ensured by preventing the second fins 33 from being excessively dense.

  Further, since the twisted shape of the second fin 33 can be easily obtained by simply twisting the metal plate as will be described later, the second fin 33 is simpler than other shapes for disturbing the air flow A. Can be produced.

  FIG. 3 is an enlarged cross-sectional view of the heat exchanger 12 as viewed from the upstream side of the air flow A.

  As described above, since the second fins 33 adjacent to each other in the direction D3 are separated from each other, a gap C is formed between the first fins 32.

  By providing the gap C in this way, it is possible to prevent the air flow A from passing through the heat exchanger 12 due to the second fins 33 and to increase the pressure loss of the heat exchanger 12 more than necessary. Can be prevented. The pressure loss means a difference between the pressure of the air flow A immediately before entering the heat exchanger 12 and the pressure of the air flow A immediately after leaving the heat exchanger 12, and the air passage in the heat exchanger 12 is easy. It is a guideline for the size.

  If the pressure loss rises, the air flow A becomes difficult to pass through the heat exchanger 12, so that it is necessary to increase the rotation speed of the fan 15 (see FIG. 1). It is possible to suppress the increase in the rotational speed and prevent the power consumption of the fan 15 from increasing.

  Although the pressure loss depends on the opening ratio of the heat exchanger 12, in this embodiment, the opening ratio is proportional to the total surface area of the first fin 32 and the second fin 33. Depends on.

  FIG. 4 is a graph obtained by simulating how the pressure loss changes depending on the total surface area.

  The horizontal axis of this graph represents the rate of increase of the total surface area when the second fin 32 is not provided and is based on the total surface area.

  As is apparent from FIG. 4, the pressure loss increases as the increase rate of the total surface area increases.

  As described above, an increase in pressure loss causes an increase in power consumption in the fan 15. Therefore, the surface area of the second fin 33 is preferably set to a minimum size that can obtain the heat exchange efficiency required by the specifications.

  In the heat exchanger 12 shown in FIG. 2, when the flow velocity of the air flow A immediately before entering the heat exchanger 12 is 3 m / s, the pressure loss is about 40 Pa. Since the pressure loss when the second fin 33 is not present at the same flow rate is about 30 Pa, in this embodiment, the pressure loss increases about 1.1 times as compared with the case where the second fin 33 is not present. If so, the power consumption of the fan 15 is not a problem.

  Next, the manufacturing method of the heat exchanger 12 provided with the above-mentioned 2nd fin 33 is demonstrated.

  Fig.5 (a) is a top view in the middle of manufacture of the 2nd fin 33, FIG.5 (b) is sectional drawing which follows the II line | wire of Fig.5 (a).

  First, as shown in FIGS. 5A and 5B, an aluminum plate 33a having a strip shape in plan is prepared. Instead of the aluminum plate 33a, another metal plate such as a copper plate may be used.

  And the pipe part 33b which protruded from the main surface 33x of the aluminum plate 33a is formed by giving a drilling process and a drawing process to the aluminum plate 33a. The inner surface of the pipe portion 33b defines an opening through which the refrigerant pipe 31 (see FIG. 2) is inserted.

  If the height H of the pipe portion 33b measured from the main surface 33x is too high, the interval p1 (see FIG. 2) between the first fins 32 adjacent to each other due to the pipe portion 33b cannot be reduced. For this reason, the height H is preferably about half of the interval p1, for example, about 1.5 mm.

  Next, the steps shown in FIGS. 6A and 6B will be described. FIG. 6A is a top view in the process of manufacturing the second fin 33, and FIG. 6B is a side view thereof.

  In this step, the basic structure of the second fin 33 provided with a twisted shape is completed by twisting the aluminum plate 33a twice by machining.

  The second fin 33 manufactured in this way has an attachment portion 33c attached to the refrigerant pipe 31, and a fin portion 33d provided with a twisted shape on both sides of the attachment portion 33c.

  Next, as shown in the perspective view of FIG. 7, the first fin 32 having a plurality of holes 32 a is prepared, and the refrigerant pipe 31 is provided in each of the hole 32 a and the pipe portion 33 b of the second fin 33. And the first fins 32 and the second fins 33 are alternately stacked.

  The outer diameter of the refrigerant pipe 31 is not particularly limited, but in the present embodiment, the outer diameter is about 10 mm. In this case, the inner diameter of each of the hole 32a and the pipe portion 33b may be about 10.3 mm so that the refrigerant pipe 31 can be inserted.

  The planar shape of the first fin 32 is a rectangular shape having a side length of about 1.5 m to 2 m.

  Then, as shown in the side view of FIG. 8, the R pipe | tube 37 for connecting the some refrigerant | coolant piping 31 is prepared. Instead of the R pipe, a U-shaped pipe having straight pipe portions at both ends of the R pipe may be used.

  Next, as shown in the side view of FIG. 9, the R pipe 37 and the refrigerant pipe 31 are connected by brazing in a state where the refrigerant pipe 31 is inserted into each of the plurality of R pipes 37.

  Thereafter, the refrigerant pipe 31 is expanded by supplying air having a pressure higher than the atmospheric pressure into the refrigerant pipe 31.

  FIG. 10 is an enlarged sectional view of the expanded refrigerant pipe 31 and its surroundings.

  By expanding the refrigerant pipe 31 in this way, the inner surface 33y of the pipe portion 33b of the second fin 33 is crimped to the outer peripheral side surface of the refrigerant pipe 31, and the second fin 33 is mechanically fixed to the refrigerant pipe 31. The

  In particular, the inner surface 33y of the pipe portion 33b is pressure-bonded to the outer peripheral side surface of the refrigerant pipe 31 in a surface contact state, so that the second fin is mechanically and firmly attached to the refrigerant pipe 31 as compared with the case where the pipe portion 33b is not provided. 33 can be attached.

  Similarly, since the holes 32 a of the first fins 32 are also crimped to the outer peripheral side surface of the refrigerant pipe 31, the first fins 32 are also mechanically fixed to the refrigerant pipe 31.

  Thus, the basic structure of the heat exchanger 12 according to this embodiment is completed.

  According to the above-described embodiment, as shown in FIG. 2, not only the flat plate-like first fins 32 but also the second fins 33 are provided, so that the gap between the second fins 33 and the airflow A is provided. However, heat exchange is performed, and the heat exchange efficiency of the heat exchanger 12 is increased.

  In particular, by twisting the second fin 33 about the direction D2 along the flow path of the air flow A as a central axis, the air flow A is rotated along the surface of the second fin 33 to cause pressure loss in the heat exchanger 12. Can be prevented and an increase in power consumption of the fan 15 (see FIG. 1) can be suppressed.

  Thereby, in this embodiment, it becomes possible to aim at coexistence with the improvement of the heat exchange rate of the heat exchanger 12, and suppression of the power consumption of 10 of an air conditioner.

(Second Embodiment)
In the present embodiment, more torsional shapes are given to one second fin 33 than in the first embodiment.

  Below, the heat exchanger provided with such 2nd fin 33 is demonstrated, following the manufacturing process, referring FIGS. 11-13. 11 to 13, the same elements as those described in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted below.

  Fig.11 (a) is a top view in the middle of manufacture of the 2nd fin 33 which concerns on this embodiment, FIG.11 (b) is sectional drawing which follows the II-II line | wire of Fig.11 (a).

  First, an aluminum plate 33e as shown in FIGS. 11A and 11B is prepared. The planar shape of the aluminum plate 33e corresponds to the developed shape of the second fins 33 produced in the present embodiment, and is a closed figure provided with a plurality of strip portions 33f.

  Then, by drilling and drawing the aluminum plate 33e, a tube portion 33b protruding from the main surface 33x of the aluminum plate 33e by a height H of about 1.5 mm is formed.

  Note that another metal plate such as a copper plate may be used instead of the aluminum plate 33e.

  Next, the steps shown in FIGS. 12A and 12B will be described. FIG. 12A is a top view in the process of manufacturing the second fin 33 according to the present embodiment, and FIG. 12B is a side view thereof.

  In this step, the basic structure of the second fin 33 provided with a plurality of fin portions 33d provided with a twisted shape is completed by twisting each of the aforementioned strip portions 33f twice by machining.

  After this, the basic structure of the heat exchanger 12 according to this embodiment shown in the partially exploded perspective view of FIG. 13 is completed by performing the steps of FIGS. 7 to 10 described in the first embodiment.

  According to the present embodiment described above, as shown in FIG. 11A, by processing the aluminum plate 33e whose planar shape is a single closed figure, it is not necessary to make a part for each fin portion 33d. The second fin 32 in which the plurality of fin portions 33d and the attachment portion 33c are integrated can be produced.

  Furthermore, since the surface area of the second fin 33 is increased by increasing the number of the fin portions 33d in this way, heat exchange is efficiently performed between the second fin 33 and the air flow A, so that the first Compared with the embodiment, the heat exchange efficiency of the heat exchanger 12 is increased.

  The following additional notes are disclosed for each embodiment described above.

(Supplementary note 1) Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to an air flow;
A second fin attached to the refrigerant pipe between the adjacent first fins and twisted with the direction along the air flow as a central axis of twist;
The heat exchanger characterized by having.

  (Supplementary note 2) The heat exchanger according to supplementary note 1, wherein a plurality of the second fins are provided apart from each other in a direction orthogonal to the direction along the air flow.

(Supplementary Note 3) The second fin includes an attachment portion formed with an opening that is crimped to an outer peripheral side surface of the refrigerant pipe;
The heat exchanger according to appendix 1 or appendix 2, wherein the heat exchanger includes a fin portion extending from the attachment portion and provided with a twisted shape.

  (Additional remark 4) The heat exchanger of Additional remark 3 characterized by the above-mentioned. The said fin part was provided in the both sides of the said attaching part.

(Supplementary Note 5) A plurality of the fin portions are provided in the second fin,
4. The heat exchanger according to appendix 3, wherein the developed shape of the second fin is a closed figure provided with a plurality of strip portions corresponding to each of the plurality of fin portions.

(Supplementary Note 6) The second fin has a pipe portion protruding from the main surface of the mounting portion,
The heat exchanger according to any one of appendix 3 to appendix 5, wherein the opening is defined by an inner surface of the pipe portion.

  (Supplementary note 7) The heat exchanger according to any one of supplementary notes 1 to 6, wherein the first fin has a flat plate shape.

  (Supplementary note 8) The heat exchanger according to any one of supplementary notes 1 to 7, wherein an extending direction of the refrigerant pipe is orthogonal to a direction along the air flow.

(Supplementary note 9) a fan that generates an air flow;
A heat exchanger exposed to the air stream,
The heat exchanger is
Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to the airflow;
An air conditioner comprising: a second fin attached to the refrigerant pipe between the adjacent first fins and twisted with a direction along the air flow as a central axis of twisting.

(Supplementary Note 10) An information processing device that is provided in the device installation area and performs information processing;
An air conditioner having a fan that generates an air flow for cooling the information processing device and a heat exchanger that is exposed to the air flow;
The heat exchanger is
Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to the airflow;
An information processing system comprising: a second fin that is attached to the refrigerant pipe between the adjacent first fins and twisted with a direction along the airflow as a central axis of twisting.

DESCRIPTION OF SYMBOLS 1 ... Information processing system, 10 ... Air conditioner, 12 ... Heat exchanger, 13 ... Housing, 14 ... Fan unit, 15 ... Fan, 17 ... Data center, 18 ... Equipment installation area, 19 ... Cold aisle, 20 ... Server Rack, 21 ... Computer, 21a ... Intake surface, 21b ... Exhaust surface, 31 ... Refrigerant piping, 32 ... First fin, 32a ... Hole, 33 ... Second fin, 33a, 33e ... Aluminum plate, 33b ... Pipe part , 33c: mounting portion, 33d: fin portion, 33f: strip portion, 33x: main surface, 37: R tube.

Claims (6)

Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to an air flow;
A second fin attached to the refrigerant pipe between the adjacent first fins and twisted with the direction along the air flow as a central axis of twist;
The heat exchanger characterized by having.   2. The heat exchanger according to claim 1, wherein a plurality of the second fins are provided apart from each other in a direction orthogonal to the direction along the air flow. The second fin includes an attachment portion formed with an opening that is crimped to an outer peripheral side surface of the refrigerant pipe;
The heat exchanger according to claim 1, further comprising a fin portion extending from the attachment portion and provided with a twisted shape. A fan that produces an air flow;
A heat exchanger exposed to the air stream,
The heat exchanger is
Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to the airflow;
An air conditioner comprising: a second fin attached to the refrigerant pipe between the adjacent first fins and twisted with a direction along the air flow as a central axis of twisting. An information processing device for information processing provided in the device installation area;
An air conditioner having a fan that generates an air flow for cooling the information processing device and a heat exchanger that is exposed to the air flow;
The heat exchanger is
Refrigerant piping,
A plurality of first fins attached to the refrigerant pipe at intervals and exposed to the airflow;
An information processing system comprising: a second fin that is attached to the refrigerant pipe between the adjacent first fins and twisted with a direction along the airflow as a central axis of twisting. Forming a tube portion protruding from the main surface of the metal plate by drilling the metal plate; and
Producing a fin imparted with a twisted shape by twisting the metal plate;
Inserting a refrigerant pipe through the pipe portion;
Expanding the refrigerant pipe by supplying air at a pressure higher than atmospheric pressure into the refrigerant pipe, and crimping the inner surface of the pipe portion and the outer peripheral side surface of the refrigerant pipe;
A method for producing a heat exchanger, comprising:

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