JP2013202655A - Method of manufacturing heat transfer member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a microstructure surface in a reentrant cavity shape on a heat transfer surface of a heat transfer member with high precision.SOLUTION: A projection/recess part 3 having a prescribed pitch is formed by irradiating a heat transfer surface 2 of a heat transfer member 9 with an electron beam, and bent parts 6 are formed by bending tips of projection parts 3a of the projection/recess part 3 so as to form a heat transfer surface 2 having reentrant cavities 1.

Description

  The present invention relates to a method for manufacturing a heat transfer member used in power equipment, heat exchangers, and the like.

  In order to increase the heat dissipation area and improve the cooling efficiency of conventional heat transfer members used in power equipment and heat exchangers, heat dissipation fins are installed on the heat transfer surface of the heat transfer member ( Patent Document 1), irregularities and the like are formed on the inner and outer surfaces. These heat dissipating means can improve the heat transfer efficiency and can remove more heat per unit heat transfer area.

  In order to improve the heat transfer efficiency, particularly the boiling heat transfer efficiency, it is necessary to generate a large number of boiling bubbles on the heat transfer surface and to quickly release the generated bubbles so that the heat transfer surface does not dry. That is, it is necessary to provide a heat transfer surface that stably generates boiling bubbles and quickly releases them.

  Many factors influence the improvement of the boiling heat transfer efficiency. The main parameter is the surface properties on the heat transfer surface. In order to improve boiling heat transfer efficiency, it is desirable that concave portions such as fine pits and cavities are formed on the heat transfer surface, and bubbles are generated by forming bubble generation nuclei starting from these concave portions. Is activated and heat transfer is improved. Therefore, it has been proposed to artificially provide minute pits and cavities on the heat transfer surface in order to improve boiling heat transfer efficiency. Such a microstructured surface is formed from a porous layer obtained by performing sintering, thermal spraying or plating treatment of metal particles or fibers in layers on the surface of the heat transfer surface (Patent Document 2), machining or It is formed by electron beam irradiation (Patent Document 3).

Further, as an example of the heat transfer surface in which the minute pits and cavities are formed, the heat transfer surface in which the fine structure surface having the reentrant cavities 1 as shown in FIG. Members are known. Since the microstructural surface formed of the reentrant cavity 1 can generate bubbles actively and stably in the concave portion, the boiling heat transfer efficiency is greatly improved as compared with the smooth tube.
The microstructure surface having the reentrant cavity is formed of a porous layer or formed by machining or rolling.

JP 2000-346579 A JP 2000-54159 A JP 2012-13396 A

As described above, a microstructured surface having a conventional reentrant cavity is formed by a porous layer or machining. However, the porous layer formed by sintering, thermal spraying, or the like has a problem that the surrounding fluid causes wear or peeling over time.
Further, when machining or the like is used, there is a problem that fine machining is difficult depending on the material of the heat transfer member, and the time and cost required for the fine machining are increased.

  The present invention has been made in order to solve the above-described problem, and provides a method for manufacturing a heat transfer member that can easily and accurately form a microstructured surface having a reentrant cavity on the heat transfer surface of the heat transfer member. The purpose is to provide.

  In order to solve the above-described problem, a method for manufacturing a heat transfer member according to the present invention forms an uneven portion having a predetermined pitch by irradiating an electron beam onto a heat transfer surface of the heat transfer member, and then A heat transfer surface having a reentrant cavity is formed by forming a bent portion by bending the tip of the convex portion.

  Moreover, the manufacturing method of the heat-transfer member which concerns on this invention forms an uneven | corrugated | grooved part of a predetermined pitch by irradiating an electron beam to the heat-transfer surface of a heat-transfer member, and then presses the convex part of the said uneven | corrugated | grooved part. A heat transfer surface having a reentrant cavity is formed by forming a flat portion.

  Moreover, the manufacturing method of the heat-transfer member which concerns on this invention forms a recessed part of predetermined pitch by irradiating an electron beam from the perpendicular | vertical upper direction of the heat-transfer surface of the said heat-transfer member in the state which inclined the heat-transfer member by the predetermined angle. Thus, a heat transfer surface having a reentrant cavity is formed.

  In addition, the method for manufacturing a heat transfer member according to the present invention forms a through hole having a predetermined pitch by irradiating one surface of the heat transfer member with an electron beam, and then fixes a thin plate on the surface to make the reentrant. A heat transfer surface having a cavity is formed.

  According to the present invention, a microstructure surface having a reentrant cavity on the heat transfer surface of a heat transfer member can be easily formed with high accuracy.

(A) is a schematic sectional drawing which shows the 1st step of the manufacturing method of the heat-transfer member which concerns on 1st Embodiment, (b) is a schematic sectional drawing which shows a 2nd step. The schematic sectional drawing which shows the manufacturing method of the heat-transfer member which concerns on 2nd Embodiment. The schematic sectional drawing which shows the manufacturing method of the heat-transfer member which concerns on 3rd Embodiment. The schematic sectional drawing which shows the manufacturing method of the heat-transfer member which concerns on 4th Embodiment. (A) is a schematic sectional drawing which shows the 1st step of the manufacturing method of the heat-transfer member which concerns on 5th Embodiment, (b) is a schematic sectional drawing which shows a 2nd step. The block diagram of a general Lietrant cavity.

Hereinafter, an embodiment of a manufacturing method of a heat transfer member concerning the present invention is described with reference to drawings.
(First embodiment)
The manufacturing method of the heat-transfer member which concerns on the 1st Embodiment of this invention is demonstrated with FIG. 1 (a), (b).
First, as shown in FIG. 1A, the uneven portions 3 having a predetermined pitch are formed on the heat transfer surface 2 of the heat transfer member 9 by electron beam irradiation (first step).

  Next, as shown in FIG. 1B, the tip of the convex portion 3a is bent by machining using a roller 5 or the like on the heat transfer surface 2 on which the concavo-convex portion 3 is formed, so that the bent portion 6 is formed. Then, the reentrant cavity 1 is formed (second step).

  In the present embodiment, a reentrant cavity having an opening 4 by bending the tip of a convex portion 3 a by rotating a rolling member 5 for machining such as a roller on the heat transfer surface 2 on which the concave and convex portion 3 is formed. 1 is formed.

When the rolling member 5 is rotationally moved, the distance between the rolling member 5 and the heat transfer surface 2, the rotational movement speed, and the like depend on the pitch of the concave and convex portions 3, the depth of the concave portions 3b, the material of the heat transfer member, and the like. The reentrant cavity 1 having a predetermined opening 4 is appropriately set.
The reentrant cavity 1 only needs to have a cross-sectional area larger than the cross-sectional area of the opening 4 inside.

  According to this embodiment, the heat transfer member is formed by a simple manufacturing method in which a fine uneven portion is formed on the surface of the heat transfer member using an electron beam, and then the tip of the protrusion is bent by machining or the like. A reentrant cavity having a predetermined pitch can be formed on the heat transfer surface with high accuracy and efficiency. Thereby, the heat transfer characteristic of a heat transfer member can be improved significantly.

(Second Embodiment)
A method for manufacturing a heat transfer member according to the second embodiment of the present invention will be described with reference to FIG.
First, similarly to the first embodiment, the heat transfer surface 2 is irradiated with an electron beam to form fine irregular portions 3 (FIG. 1A) having a predetermined pitch (first step).

Next, a predetermined press load or the like is applied to the tip portion of the convex portion 3a of the concavo-convex portion 3 (not shown) to form a flat portion 7 on each tip portion 3a as shown in FIG. 2 (second step) ).
Thereby, the reentrant cavity 1a having the opening 4 is formed.

  In the first and second embodiments, when the reentrant cavity 1 is formed by bending or pressing the convex portion 3a, the reentrant capable of securing air bubbles is required unless the depth of the concave and convex portion 3 is increased to some extent. A concave portion cannot be formed. As a result of experiments, it has been confirmed that the depth of the concave portion 3b of the concave and convex portion 3 should be 40 μm or more in order to obtain the reentrant cavity 1 that can generate bubbles actively and stably.

As described above, according to the present embodiment, a simple uneven portion 3 is formed on the surface of the heat transfer member using an electron beam, and then the tip of the protruded portion 3a is flattened by machining or the like. With this manufacturing method, the reentrant cavities 1 having a predetermined pitch can be formed with high accuracy and efficiency on the heat transfer surface of the heat transfer member. Thereby, the heat transfer characteristic of a heat transfer member can be improved significantly.
Moreover, the reentrant cavity 1 which can generate a bubble actively and stably can be obtained by the depth of the recessed part 3b being 40 micrometers or more.

(Third embodiment)
A method for manufacturing a heat transfer member according to the third embodiment of the present invention will be described with reference to FIG.
First, as in the above embodiment, the heat transfer surface 2 is irradiated with an electron beam to form fine uneven portions 3 (FIG. 1A) having a predetermined pitch (first step).

Next, as shown in FIG. 3, the mesh net 8 is fixed to the surface of the concavo-convex portion 3 by adhesion or the like (second step).
As the net plate 8, a net plate 8 having a pitch equal to the pitch of the concavo-convex portion 3 and a gap width of the net plate 8 smaller than the pitch of the convex portions 3a is used. At that time, since the concavo-convex portions 3 are regularly arranged by controlled electron beam processing, the net plate 8 can be arranged so as to match the convex portions 3a by precise alignment.

Thereby, the reentrant cavity 1b is formed between the net part of the net plate 8 and each convex part 3a.
When the heat transfer member is a cylinder, the cylindrical heat transfer surface 2 is irradiated with an electron beam to form the concavo-convex portion 3, and then the mesh net 8 is wound around the concavo-convex portion 3 and fixed by adhesion or the like. By doing so, the reentrant cavity 1b is formed (not shown).

  Further, when a cylindrical heat transfer member is manufactured from a flat plate, the flat plate is irradiated with an electron beam to form the concavo-convex portion 3, and the net plate 8 is fixed to the flat concavo-convex portion 3 by bonding or the like, and then bent. It is processed into a cylindrical shape by processing or the like (not shown).

  According to the present embodiment, the heat transfer member is formed by a simple manufacturing method in which fine uneven portions 3 are formed on the surface of the heat transfer member 9 using an electron beam, and then the net plate 8 is fixed to the protrusions 3a. The reentrant cavities 1b having a predetermined pitch can be formed with high accuracy and efficiency on the nine heat transfer surfaces 2.

(Fourth embodiment)
A method for producing a heat transfer member according to the fourth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, the heat transfer member 9 is tilted by a predetermined angle, and the electron beam 10 is irradiated from vertically above the heat transfer surface 2.

  As a result, the uneven portion 3 is formed on the heat transfer surface 2 as shown in FIG. In the heat transfer surface 2 on which the concavo-convex portion 3 is formed, the concave portion 3b functions as a reentrant cavity 1c when in use.

  The shape of the reentrant cavity 1c differs depending on the inclination angle of the heat transfer member 9 when the electron beam 10 is irradiated. By adjusting this angle, a reentrant cavity 1c having a desired shape can be obtained.

  Since the shape of the reentrant cavity 1c, in which bubble nuclei are likely to be generated, is desirably small on the surface side and wide on the inner side, the inclination angle of the heat transfer member 9 during irradiation with the electron beam 10 is at least 30 degrees or more. It is desirable.

  According to the present embodiment, the reentrant cavity 1c having a predetermined pitch is highly accurately and efficiently formed on the heat transfer surface 2 of the heat transfer member 9 by a simple manufacturing method in which the heat transfer member 9 is tilted and irradiated with the electron beam 10. Can be formed.

(Fifth embodiment)
The manufacturing method of the heat-transfer member which concerns on the 5th Embodiment of this invention is demonstrated with FIG. 5 (a), (b).
When the heat transfer member 9 is irradiated with the electron beam 10, generally, a through hole 11 having an inverted conical shape is formed as shown in FIG.

  In this embodiment, first, as shown in FIG. 5A, one surface of the heat transfer member 9 is irradiated with an electron beam 10 so as to penetrate the plate thickness of the heat transfer member 9, and a through hole having a predetermined pitch is formed. 11 is formed (first step).

Next, as shown in FIG. 5B, the thin plate 12 is fixed to the surface by adhesion or the like (second step). Thereby, the through-hole 11 can be used as the reentrant cavity 1d.
Moreover, when the heat transfer member 9 is cylindrical, after implementing the said step with a flat plate, the cylindrical heat transfer member 9 is formed by bending.

According to the present embodiment, the heat transfer surface 2 is irradiated with the electron beam 10 and penetrated, and then the thin plate 12 is fixed to the back surface of the heat transfer surface 2 by a predetermined pitch on the heat transfer surface 2 of the heat transfer member 9. The reentrant cavity 1d can be formed with high accuracy and efficiency.
In the above-described embodiment, an example in which an electron beam is used as a means for forming an uneven portion or the like has been described. However, the present invention is not limited to this, and other irradiation means such as laser light may be used.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, combinations, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1, 1a, 1b, 1c, 1d ... reentrant cavity, 2 ... heat transfer surface, 3 ... uneven portion, 3a ... convex portion, 3b ... concave portion, 4 ... opening, 5 ... rolling member, 6 ... bent portion, 7 ... Flat part, 8 ... Net plate, 9 ... Heat transfer member, 10 ... Electron beam, 11 ... Through hole, 12 ... Thin plate.

Claims (6)

  Irradiation with an electron beam on the heat transfer surface of the heat transfer member forms a concavo-convex portion having a predetermined pitch, and then a bent portion is formed by bending the tip of the convex portion of the concavo-convex portion, thereby having a reentrant cavity. A method of manufacturing a heat transfer member, wherein a heat transfer surface is formed.   Heat transfer surface having a reentrant cavity by forming an uneven portion with a predetermined pitch by irradiating an electron beam onto the heat transfer surface of the heat transfer member, and then forming a flat portion by pressing the convex portion of the uneven portion A method of manufacturing a heat transfer member, comprising forming a surface.   Forming a heat transfer surface having a reentrant cavity by forming a recess with a predetermined pitch by irradiating an electron beam from vertically above the heat transfer surface of the heat transfer member with the heat transfer member inclined at a predetermined angle. A method for manufacturing a heat transfer member.   The depth of the recessed part formed of the said electron beam shall be 40 micrometers or more, The manufacturing method of the heat-transfer member of any one of Claim 1 thru | or 3 characterized by the above-mentioned.   The method for manufacturing a heat transfer member according to claim 3, wherein the heat transfer member is inclined by 30 degrees or more.   A heat transfer surface having a reentrant cavity by forming a through-hole with a predetermined pitch by irradiating the heat transfer surface of the heat transfer member with an electron beam and then fixing a thin plate on the opposite side of the heat transfer surface of the heat transfer member The manufacturing method of the heat-transfer member characterized by forming.

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