JPH0645175Y2 - Heat transfer surface structure of two-phase flow heat absorber - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to improvement of the heat transfer surface of a two-phase flow heat absorber that also absorbs latent heat of vaporization to cool equipment used in spacecraft and the like. It is suitable for use in.

[Prior Art] One of the heat absorbers that cools devices that generate heat during operation is a two-phase flow heat absorber that uses a two-phase flow accompanied by boiling and condensation. It has the advantages of higher heat transfer efficiency, smaller refrigerant flow rate, smaller size and lighter weight, and lower power consumption.

For this reason, it is considered to use a two-phase flow heat absorber for cooling equipment mounted on spacecraft.

Such a two-phase flow heat absorber is provided with a rectangular parallelepiped heat sink body 1 as shown in, for example, FIGS. 3 and 4, and for example, its upper plate is used for mounting devices or the like. The endothermic plate 2 is endothermicly cooled.

Then, the heat medium inlet 5 is provided on the front and rear side plates 3 and 4 of the heat absorber main body 1.
And outlet 6 are formed to communicate with the heat medium inlet 5, and U-shaped partition walls 7 are provided around the front part and the left and right sides inside the heat absorber main body 1 to form a liquid flow path 8. A partition wall 9 and a buffer plate 10 which are parallel to each other in the front and rear are provided in the central portion inside the U-shaped portion, and a long vapor flow path 11 is formed in the front and rear so as to communicate with the heat medium outlet 6.

Furthermore, between the liquid flow path 8 and the vapor flow path 11, a wick material 12 is arranged in the shape of a bar that rises in the left-right direction, and its ends are attached so as to contact the heat absorbing plate 2 and the lower plate 13, respectively. At the same time, a lower wick member 14 having a space opened above is mounted on the lower plate 13 so as to come into contact with the rising wick member 12.

Further, a communication hole 15 is formed in the lower part of the partition wall 7 around the liquid flow path 8 in contact with the lower wick material 14, and a communication hole 16 is also formed in the upper part of the partition wall 9 forming the vapor flow path 11. There is.

In the two-phase flow heat absorber configured as described above, when a device to be cooled is placed on the heat absorbing plate 2 and a condensed liquid heat medium such as ammonia or chlorofluorocarbon is fed from the heat medium inlet 5. The lower wick material 14 permeates through the communication holes 15 around the liquid flow path 8 and spreads on the lower plate 13, and rises due to the capillary phenomenon to form a liquid film on the lower surface of the heat absorbing plate 1 through the rising wick material 12.

Then, the heat medium absorbs heat by cooling the equipment on the heat absorbing plate 2 and evaporates into vapor, and becomes vapor and is discharged to the outside from the steam flow path 11 and the heat medium outlet 6.

The heat medium discharged as vapor is again deprived of heat by a heat radiating condenser or a radiator (not shown), condensed and liquefied, and circulated.

[Problems to be Solved by the Invention] In such a two-phase flow heat absorber, the quality of the heat absorption efficiency is greatly influenced by the state of the liquid film formed on the back surface of the heat absorption plate 2 which is the heat transfer surface. Various researches have been conducted on the shape of the heat absorbing plate 2. For example, a standing wick material having a groove 17 formed on the back surface of the heat absorbing plate 2 and formed into a bar shape by a capillary phenomenon.
The heat medium that has proceeded to 12 is evenly guided to the entire heat absorbing plate 2, and a meniscus thin film is formed on the heat medium to improve evaporation characteristics and prevent dryout.

However, in order to fully exert the effect of the grooves 17 formed on the back surface of the heat absorbing plate 2, it is necessary to form a large number of grooves 17 having a narrow interval, which makes the processing of the heat absorbing plate 2 very complicated. There is.

Further, if the intervals between the grooves 17 are narrowed and the grooves 17 are formed in large numbers, the groove width becomes small, the liquid amount of the heat medium flowing through each groove 17 portion decreases, and there is a problem that dryout easily occurs.

Therefore, in order to prevent this, there is also a method of making the groove deeper at the same groove width and pitch, but as it approaches the heating side, nucleate boiling starts in the groove, liquid transfer becomes difficult, and dryout occurs on the downstream side. There is a problem.

The present invention has been made in view of the problems of the prior art, and an object thereof is to provide a heat transfer surface structure of a two-phase flow heat absorber in which the heat absorption plate can be easily processed and the heat absorption efficiency is high.

[Means for Solving the Problems] In order to solve the problems of the above-mentioned conventional technology, the heat transfer surface structure of the two-phase flow heat absorber of the present invention has a heat sink plate from the device with one side of the sealed heat sink body. Then, a bar-shaped wick material is attached between the heat absorbing plate and the lower plate of the heat absorber body facing the heat absorbing plate, and the heat medium on the upper surface of the lower plate is guided to the back surface of the heat absorbing plate by the bar-shaped wick material to form a thin film. In a two-phase flow heat absorber for endothermic evaporation, a honeycomb formed of a porous thin film between the back surface of the endothermic plate and the bar-shaped wick material to form a uniform meniscus thin film and a liquid channel on the back surface of the endothermic plate. It is characterized by being fitted with a wick plate.

[Operation] According to the heat transfer surface structure of this two-phase flow heat absorber, a honeycomb thin wick plate formed by bending a porous thin plate made of metal or the like is attached to the back surface of the heat absorbing plate by spot welding or the like. This is a high-performance heat transfer surface that makes it easier to process compared to the case of directly processing a groove on the heat absorbing plate, and thereby uniformly forms a thin film necessary for improving heat transfer characteristics. .

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of an embodiment of a heat transfer surface structure of a two-phase flow heat absorber of the present invention.

The basic structure of the two-phase flow heat absorber to which the heat transfer surface structure 20 of this two-phase flow heat absorber is applied is the same as that already described with reference to FIG. 3 and FIG. It has a number.

In this heat transfer surface structure 20, a honeycomb wick plate 21 which is a separate body is used without directly forming a groove for forming a thin film of a heat medium on the back surface of the heat absorbing plate 2.

This honeycomb wick plate 21 has a porous structure 22a formed by etching metal or the like as shown in an enlarged view in FIG.
Bending is performed using the porous thin plate or the wire net 22 on which are formed, and rectangular concave and convex portions are alternately formed in a honeycomb shape.

In this case, the pitch of the honeycomb-shaped irregularities of the honeycomb-shaped wick plate 21 is, for example, 3 mm, and the depth and the width are each 0.5 mm.

Then, such a honeycomb wick plate 21 is fixed to the back surface of the heat absorbing plate 2 by spot welding or the like so as to reduce the thermal resistance as much as possible by using the concave portion of the honeycomb.

It should be noted that a wick material prepared separately may be inserted into the concave portion of the honeycomb when the wick material is attached to the heat absorbing plate 2.

Further, the thickness of the heat absorbing plate 2 is also reduced to the extent that the groove is not formed so that the strength is not hindered.

In the two-phase flow heat absorber provided with such a heat transfer surface structure 20, the heat medium that has risen by the capillary phenomenon and has proceeded through the wick material 12 reaches the honeycomb-shaped wick plate 21, and further the porous portion 22a and the convex portion. The convex portion of the honeycomb is uniformly guided to the entire back surface of the heat absorbing plate 2 by the capillary phenomenon which occurs in the above, and a meniscus thin film of the heat medium is formed at the contact portion with the heat absorbing plate 2 which is the concave portion of the honeycomb.

Therefore, the heat from the device or the like placed on the front surface of the heat absorbing plate 2 is heated by the meniscus thin film portion formed on the contact surface (recess) with the honeycomb wick plate 21 attached to the back surface of the heat absorbing plate 2. Will be deprived of by thin film evaporation and will be cooled.

According to such a heat transfer surface structure 20, the honeycomb wick plate 21 can be processed separately from the heat absorbing plate 2, and since the bending process is sufficient, the process can be performed more than the conventional groove formation. In addition to being easy, since the porous thin plate 22 is used, a thin film of the heat medium can be evenly formed on the back surface of the heat absorbing plate 2, and the convex portion that serves as the liquid flow path can be separated from the heating side. This prevents dryout and improves heat transfer performance.

Next, another embodiment of the heat transfer surface structure of the two-phase flow heat absorber of the present invention will be described with reference to FIG.

In the heat transfer surface structure 30 of the two-phase flow heat absorber, the contact area with the heat absorption plate 2 is increased to improve the heat transfer characteristics and form a uniform thin film of the heat medium. For this reason, a separate honeycomb wick plate 31 is used without directly forming a groove as in the conventional case. However, unlike the honeycomb shape shown in FIG. Bending is performed so that the contact portion with the heat absorbing plate 2, which is the base end of the, is slightly opened or closed.

Then, such a honeycomb wick plate 31 is fixed to the back surface of the heat absorbing plate 2 by using a recess of the honeycomb by spot welding or the like so as to minimize the thermal resistance.

In the two-phase flow heat absorber having such a heat transfer surface structure 30, the heat medium which has risen by the capillary phenomenon and has proceeded through the wick material reaches the honeycomb-shaped wick plate 31, and the porous 32a portion and the convex portion. Due to the capillary action that occurs, the convex portions of the honeycomb are uniformly guided to the entire back surface of the heat absorbing plate 2 as a liquid flow path, and the contact area with the heat absorbing plate 2 that is the concave portion of the honeycomb has a larger area than that of the rectangular honeycomb. A meniscus thin film of the medium is formed.

As a result, the heat transfer area can be expanded, the heat absorption efficiency can be further improved, and the same effects as the above-described embodiment can be obtained.

Although the honeycomb shape of the honeycomb wick plate is rectangular or circular in the above embodiment, the present invention is not limited to this.

Further, in addition to the case where the unevenness of the honeycomb is made linear, it may be made to have a waveform.

Further, it goes without saying that various modifications may be made within the scope of the invention.

[Effects of the Invention] As described above in detail with reference to the embodiments, according to the heat transfer surface structure of the two-phase flow heat absorber of the present invention, a honeycomb wick plate formed by processing a porous thin plate into a honeycomb shape is provided. Since it is attached to the back surface of the heat absorbing plate, it can be processed more easily than when processing grooves directly on the heat absorbing plate, and it can evenly form the thin film necessary for improving heat transfer characteristics. It is possible to obtain a high-performance heat transfer surface.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an embodiment of a heat transfer surface structure of a two-phase flow heat absorber of the present invention, and FIG. 2 is a partially enlarged view of another embodiment of the present invention, FIG. 3 and FIG. FIG. 4 is a horizontal sectional view and a horizontal sectional view showing a conventional structure together with a two-phase flow heat absorber which is one of the objects to which the present invention is applied. 1: Heat absorber main body, 2: Heat absorption plate, 3, 4: Side plate, 5: Heat medium inlet, 6:
Heat medium outlet, 7, 9: partition wall, 8: liquid channel, 10: buffer plate, 11: vapor channel, 12: rising wick material, 13: lower plate, 14: lower wick material, 15, 16: communication holes , 17: groove, 20: heat transfer surface structure of two-phase flow heat absorber, 21: honeycomb wick plate, 22: porous thin plate, 22a: porous, 30: heat transfer surface structure of two-phase flow heat absorber, 31: Honeycomb wick plate, 32: porous thin plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinya Suguri, Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa 1 Ishikawajima-Harima Heavy Industries Co., Ltd. Technical Research Institute (56) Reference JP-A-61-93391 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A heat absorbing plate from a device is provided on one side of a closed heat absorbing body, and a bar-shaped wick member is attached between the heat absorbing plate and a lower plate of the heat absorbing body opposed to the heat absorbing plate. In a two-phase flow heat absorber that guides the heat medium on the upper surface to the back surface of the endothermic plate by a bar-shaped wick material and forms a thin film to endothermically evaporate, a porous thin plate between the bar-shaped wick material on the back surface of the endothermic plate. A heat transfer surface structure of a two-phase flow heat absorber, characterized in that a honeycomb-shaped wick plate which is formed by the above-mentioned and which forms a uniform meniscus thin film and a liquid flow path is mounted on the back surface of the heat absorption plate.