JPS61153384A - Heat pipe - Google Patents

Abstract

PURPOSE:To improve the mechanical strength of a heat pipe without making the size larger and at the same time contrive to facilitate the manufacture by a structure wherein refrigerant return passages, each of which ranges from the evaporator section to the condenser section and has a large cross section, are arranged between the inner tube and the outer tube of the heat pipe and similarly grooves with small cross section are arranged onto the inner surface of the inner tube and further communicating holes are provided between the grooves and the return passages. CONSTITUTION:Refrigerant, with the quantity of which the grooves 5 of an inner tube 3 and refrigerant return passages can be filled up, is sealed in a heat pipe after the pipe is evacuated. The refrigerant evaporated at the evaporator section reaches the condenser section through an evaporating passage 9. The liquid refrigerant condensed at the condenser section returns to the evaporator section mainly through the refrigerant return passages 7. Consequently, large flow rate is produced even by the slight capillary attraction of the groove 5, resulting in making the occurrence of drying-out at the evaporator section difficult and enabling to obtain the large heat transport capacity. In addition, because the outer tube 1 and the inner tube 3 directly contacts with each other at some portion, heat can efficiently be transmitted through th outer tube 1 to the evaporating surface and the condensing surface on the inner tube 3 side and no large heat resistance at the evaporator section and the condenser section, which may develop in an artery heat pipe employing mesh as wicking material, develops.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a heat pipe.

[Technical Background of the Invention] Conventionally, there is a heat pipe in which a condensate return path is specially provided between a condensing section and an evaporating section in order to increase the heat transport ability of the heat pipe.

This type of arch reheat pipe is shown in FIGS. 5 and 6, for example. The one in FIG. 51 has a mesh 503 as a wick attached to the inner surface of the tube body 501, and
3 is deformed to form a return path 505 for the condensate. In addition, FIG. 6 shows a circumferential groove 603 on the inner surface of the tube body 601.
In addition, a felt-like gold bottom 605 is inserted inside the tube body 601 to form a return path for the condensate. In addition, the heat pipe in FIG. 7 has inside the container 701,
This is a so-called monogroup heat vibe in which a condensate return path 707 is provided separately from a steam passage 705 having a circumferential groove 703.

[Problems with the Background Art] However, in the conventional example shown in FIGS. 5 and 6, when the heat pipe receives some kind of vibration, the internal mesh 503 (FIG. 5) and the felt-like metal 605 (
In addition to problems with mechanical strength such as deformation or displacement of the inserts (Fig. 6), it is extremely difficult to manufacture these inserts so that they fit tightly against the inner surface of the tube body 1, and in addition, in the case of Fig. 5 In this case, there is a possibility that a liquid film exists between the mesh 503 and the inner cavity of the tube body 501, which causes problems such as an increase in thermal resistance.

On the other hand, the one in FIG. 7 has no insert inside, so the above problem can be solved, but the steam passage 705 and the condensate return passage 707 are provided separately, so the heat pipe is There is a problem that the size and weight increase, and as can be said in the example of FIG. 6, the circumferential groove 703
A difficult machining process must be performed to provide a circumferential groove (circumferential groove 603 in FIG. 6) on the inner surface of the passage.

[Purpose of the Invention] This invention was devised @it7 in view of these conventional problems, and provides a heat pipe that improves mechanical strength without increasing its size and is relatively easy to manufacture. purpose.

[Summary of the Invention] In order to achieve this object, the present invention has an outer tube and an inner tube inserted into the outer tube, and a comparison between the inner tube and the outer tube extends from the evaporation section to the condensation section. A refrigerant return path with a large cross-sectional area is provided, and a groove with a relatively small cross-sectional area is provided on the inner surface of the inner tube extending from the evaporation section to the U section. A communication hole was provided in the inner tube 677 to allow communication between the two.

[Effects of the Invention] This invention provides a groove on the outer surface of the inner tube to prevent the generation of capillary tubes and horns, a refrigerant return path between the inner tube and the outer tube, and a groove between the refrigerant return path and the surface groove. Since the heat pipes are communicated with each other through a communication hole, there is no need to separately provide a steam passage and a condensate return path, and there is no insert such as a mesh inside, so the mechanical strength can be increased without increasing the size of the heat pipe. can be improved.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a cross-sectional view of a heat pipe in which an inner tube 3 is inserted into a sealed outer tube 1 in a tight state, and FIG. 2 is a perspective view of the inner tube 3. The inner surface of the inner tube 3 is provided with a hole having a relatively small cross-sectional area and facing in the axial direction, and the outer surface of the inner tube 3 has a hole having a relatively large cross-sectional area and facing in the axial direction. A refrigerant return path 7 is provided. Furthermore, a vapor passage 9 for the refrigerant evaporated in the evaporator section is formed inside the inner tube 3. The grooves 5 have the function of generating a pressure difference by capillary force to cause the liquid refrigerant to flow from the condensing section to the evaporating section, and also performing heat transfer during condensation and evaporation. For this reason, the polygon 5 is thin and has a wide area in contact with the vapor phase. The refrigerant return path 7 is so-called an arteri, and is provided between the outer tube 1 and the inner tube 3, and is configured to flow the liquid refrigerant condensed in the condensing section to the evaporating section. It is the main return route. Therefore, in order to reduce the flow resistance of the liquid refrigerant when it returns, the cross-sectional area of the refrigerant return path 7 is made relatively large.

Further, a plurality of slits 11 are provided in the inner tube 3 in the circumferential direction as communication holes for communicating the groove 5 and the refrigerant return path 7. This slit 11 is formed on the outer circumferential side of the inner tube 3 over the entire circumference, and communicates with the groove 5 on the inner circumferential side.

Create a vacuum inside the heat pipe configured like this! After ζ, fill with a suitable refrigerant. This amount may be small enough to fill the groove 5 of the inner tube 3 and the refrigerant return path 7.

The refrigerant evaporated in the evaporation section passes through the evaporation passage 9 and reaches the condensation section, and the liquid refrigerant condensed here mainly flows back to the evaporation section through the refrigerant return path 7. For this reason, i&5
Since a large flow rate can be obtained even with a small capillary force, dryout in the evaporation section does not occur and a large heat transport capacity can be obtained.

Further, since the outer tube 1 and the inner tube 3 have a portion in direct contact with each other, heat can be efficiently transferred through the outer tube 1 to the evaporation surface and the condensation surface on the inner tube 3 side. Therefore, unlike arch reheat pipes using mesh, large thermal resistance does not occur in the evaporation section and the condensation section.

In addition, since the inner tube 3 is formed by extrusion molding and the slit 11 is formed from the outer surface, it is relatively easy to insert the inner tube 3 into the outer tube 1 in a tight manner. This can be easily done by cold fitting or the like.

FIG. 3 is a sectional view of a heat pipe showing another embodiment. In addition, here, the same reference numerals are attached to the same components as in the above-described embodiment to simplify the explanation.

That is, in this embodiment, a part of the inner tube 3 is made to protrude toward the steam passage 9, so that a refrigerant return path 7 is provided between the outer tube 1 and the inner tube 3. An iM 5 is provided on the inner surface of the inner tube 3 where the refrigerant return path 7 is not provided, and the groove 5 and the refrigerant return path 7 are connected by a slit (not shown) substantially similar to that in FIG. It's communicating.

In this embodiment, since the cross-sectional area of the refrigerant return path 7 is increased, the flow resistance of the liquid refrigerant can be further reduced, and the contact area between the outer tube 1 and the inner tube 3 can also be increased. , the heat transfer efficiency in the evaporation section and the condensation section is further improved.

FIG. 4 shows yet another embodiment. Note that in this embodiment, the same components as those in the embodiments shown in FIGS. 1 and 2 described above (
The same reference numerals are used to simplify the explanation. This example is
The outer tube 1 has a substantially square outer shape, and four sections are provided at its four corners from the inner surface, so that a refrigerant return path 7 is provided between the outer tube 1 and the inner tube 3. The full 5 is provided around the entire inner surface of the inner pipe 3 as in FIG. 1, and the full 5 and the refrigerant return path 7 are communicated through a slit not shown, which is almost the same as in FIG. . Similar to the embodiment shown in FIG. 3, this embodiment also allows the cross-sectional area of the refrigerant return path 7 to be increased, and the contact area between the outer tube 1 and the inner tube 3 to be increased.

Note that this invention is not limited to the above-described embodiments. For example, the communication hole that connects the outer tube 1 and the inner tube 3 is
A small hole may be used instead of the slit 11, and in short, any structure that allows communication between the inside and outside of the inner tube 3 may be used.

Further, the above-described heat pipe is effective when used in outer space because all of the plurality of coolant return paths 7 can be used.

Furthermore, when used on the ground, the liquid refrigerant generally flows through the lower refrigerant return path 7 due to gravity, so the upper refrigerant return path 7 may not be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a heat pipe according to an embodiment of the present invention.
FIG. 2 is a perspective view of the inner tube in FIG. 1, FIG. 3 is a sectional view of the heat pipe of the pond embodiment, FIG. 4 is a sectional view of the heat pipe of another embodiment, and FIGS. FIG. 6 is a cross-sectional view of a conventional Arteri type heat vibrator, and FIG. 7 is a cross-sectional view of a conventional monogroup type heat pipe. (Explanation of symbols representing main parts of the drawings) 1...Outer pipe 3...Inner pipe 5...Full 7...Refrigerant return path 11...Slit (communicating hole) No. 1rlA Fig. 2 Figure 3 Figure 4 Figure 5 Figure 6 'lf

Claims (1)

[Claims] It has an outer tube and an inner tube inserted into the outer tube, and a refrigerant return path with a relatively large cross-sectional area is provided between the inner tube and the outer tube from the evaporation section to the condensation section, and the inner tube A heat pipe characterized in that a groove with a relatively small cross-sectional area is provided on the inner surface extending from the evaporating section to the condensing section, and a communication hole is provided in the inner tube to communicate the groove with the refrigerant return path.