JPS6277593A - Heat pipe - Google Patents

Abstract

PURPOSE:To miniaturize the heat pipe and improve the mechanical strength thereof by forming the heat pipe into a dual pipe consisting of an inner side pipe forming a coolant feedback path and an outer side pipe forming a vapor passage, and communicating the inner side of the outer side pipe with the outer side thereof. CONSTITUTION:A liquid coolant retained by grooves 11 formed on the inner surface of an outer side pipe 9 reaches a condensing part via a vapor passage 7. The liquid coolant condensed flows into a coolant return passage 5 via grooves 11 of an outer side pipe 9 and a communication passage 15 because of a differenece in pressure between the coolant at a condensing part and that at an evaporating part, and then circulated to the evaporating part and supplied to the groove 11 via the communicating passage 15. Since the condensed liquid coolant is fed back mainly through a coolant via a coolant feedback path 5 where the drift resistance is small, a large flow amount can be obtained even by a slight capillary force of the grooves 11, and hence a large heat transport ability can be obtained. The groove 11 is easily formed because it is sufficient to subject it to extrusion molding.

Description

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

[Technical front of the invention and its problems]

BACKGROUND ART Conventionally, in order to increase the heat transport ability of a heat pipe, there is a heat pipe in which a special return path for the condensate is provided between a condensing section and an evaporating section.

An example of this type of heat pipe is shown in FIG. 4, for example.

There is something like the one shown in Figure 5. The one shown in FIG. 4 has a mesh 103 as a wick on the inner surface of the tube body 101.
The mesh 103 is partially deformed to form a condensate return path 105. Further, in the one shown in FIG. 5, a circumferential groove 203 is provided on the inner surface of the tube body 201, and a felt-like metal 205 is inserted into the inside of the tube body 201 to form a return path for the condensate.

However, in the conventional example shown in FIGS. 4 and 5, when the heat pipe is subjected to some kind of vibration etc. In addition to problems with mechanical strength such as deformation or displacement of the inserts, these inserts may
01 (FIGS. 4 and 5) is extremely difficult to manufacture, and in addition, in the case of the mesh 103 shown in FIG. There is a possibility that a film may be present, which causes problems such as increased thermal resistance.

On the other hand, as shown in FIG. 6, inside the container 301,
There is a heat pipe called a monogroup heat pipe in which a condensate return path 307 is provided separately from a steam passage 305 having a circumferential groove 303.

The one shown in Figure 6 has no insert inside, so
Although the steam problem can be solved, since the steam passage 305 and the condensate return passage 307 are provided separately, there is a problem that the heat pipe becomes large and the ml increases. This also applies to the conventional example, but there is a problem in that difficult machining must be performed to form the circumferential groove 303 (circumferential groove 203 in FIG. 5) on the inner surface of the passage.

(Purpose of the Invention) The present invention was devised in view of these conventional problems, and aims to provide a heat pipe that has improved mechanical strength without increasing its size and is relatively easy to manufacture. shall be.

[Summary of the invention]

In order to achieve the above object, the present invention has an outer tube and an inner tube inserted into the outer tube, and the inner tube is connected to an inner tube forming a refrigerant return path and an outer tube forming a vapor passage. A groove with a relatively small cross-sectional area is provided on the inner surface of the outer tube extending from the evaporation section to the condensation section, and the groove and the groove are provided on the outer peripheral surfaces of the evaporation section side and the condensation section side. A communicating hole is provided, and a communicating path is provided between the inner tube and the outer tube to communicate the communication hole of the outer tube with the inner tube.

〔Effect of the invention〕

According to the configuration of the present invention, the inner tube has a double tube structure consisting of an inner tube forming a refrigerant return path and an outer tube forming a vapor passage, and a groove for generating capillary force is provided on the inner surface of the outer tube. At the same time, a communication hole communicating with the groove is provided on the outer circumferential surface of the outer tube, and the communication hole of the outer tube and the inner tube are communicated with each other through a communication path, so there is no need to provide an insert such as a mesh inside, so that heat can be reduced. Mechanical strength can be improved without increasing the size of the pipe. Furthermore, the inner tube and the outer tube can be brought into close contact with each other, and heat conduction to the evaporating surface or condensing surface is more efficient than that using a mesh or the like, and a heat pipe with low thermal resistance can be obtained. Since the refrigerant return path is installed inside the tube, heating can be done from all around the tube.

Manufacturing is easy because there is no need to provide a circumferential groove on the inner surface of the tube.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view of a heat pipe in which an inner tube 3 is inserted into a sealed outer tube 1 in close contact with the heat pipe, and FIG. 2 is a perspective view of the inner tube 3 without showing it. The inner tube 3 is a double tube 4 consisting of an inner tube 5 forming a refrigerant return path 4 and an outer tube 9 forming a refrigerant vapor passage 7. It is composed of l-structure. The inner surface of the outer tube 9 is provided with a groove 11 that has a relatively small cross-sectional area and is formed along the entire circumference from the evaporating section to the condensing section in the axial direction. Further, a vapor passage 7 for the refrigerant evaporated in the evaporator is formed inside the outer tube 9.

The above 11111 has a 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 the condensing action and the evaporating action. Therefore, the groove 11 is narrow and contacts the vapor phase over a wide area.

The refrigerant return path 4 constituted by the inner tube 5 is what is called an arteri, and serves as the main return path for the liquid refrigerant condensed in the condensing section to the evaporating section. Therefore, in order to reduce the flow resistance when the refrigerant liquid returns, the cross-sectional area of the refrigerant return path, that is, the inner tube 5 is made larger than that of the groove 11.

Further, a plurality of circumferential slits 13 serving as communication holes for communicating the grooves 11 and the refrigerant return path 4 are bored from the evaporating section side to the condensing section side of the outer tube 9. As shown in FIG. 2, the slit 13 is formed all around the outer circumferential surface of the outer tube 9 and communicates with the groove 11 on the inner circumferential side.

The slits 13 of the inner tube 5 and the outer tube 9 communicate with each other through a narrow communication path 15 extending in the axial direction.

The inner tube 3 is formed into an inner tube 5, an outer tube 9. by extrusion molding. The groove 11 and the communicating path 15 can be formed, and then the slit 13 can be formed from the outer surface, so it can be manufactured relatively easily. Further, the inner tube 3 can be easily inserted into the outer tube 1 in a tight state by cold fitting or the like.

In the heat pipe constructed in this way, an appropriate refrigerant is sealed so that the inside of the pipe is evacuated. This sealed amount may be enough to fill the groove 11 of the outer tube 9 and the refrigerant return path 5 .

Next, the operation of the above embodiment will be described.

In the evaporation section of the heat pipe, the liquid refrigerant held in the grooves 11 on the inner surface of the outer tube 9 evaporates, and the liquid level becomes concave due to the decrease in the amount of liquid refrigerant, and the pressure in this area decreases due to the action of surface tension. On the other hand, the refrigerant evaporated in the evaporation section passes through the vapor passage 7 and reaches the condensation section, where it is condensed. Therefore, the liquid level of the refrigerant in the groove 11 in the condensing section is approximately flat, and the pressure of the refrigerant is higher than the pressure of the refrigerant in the evaporating section.

Due to this refrigerant pressure difference, the condensed liquid refrigerant flows from the groove 11 of the outer tube 9 through the slit 13 and the communication path 15 into the refrigerant return path 5, and is returned to the evaporator. The recirculated liquid refrigerant is then supplied to the groove 11 through the communication path 15 and the slit 13. In this way, the condensed liquid refrigerant is mainly returned through the refrigerant return path 5 with low flow resistance, so a large flow rate can be obtained through the groove 11 even with a slight capillary force, and the dry Out-out is less likely to 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 meshes, large thermal resistance does not occur in the evaporation section and the condensation section.

In addition, the groove 11 of the outer tube 9 of the inner tube 3 is formed by extrusion molding, and the slit 13 is formed from the outer surface, so manufacturing is relatively easy. This can be easily done by cold fitting or the like.

Furthermore, since the refrigerant return path 5 is provided inside the inner tube 3, heating from the entire circumference of the outer tube 1 is possible.

FIG. 3 shows a sectional view of a heat pipe showing another embodiment of the present invention. Note that here, the same components as those in the above-mentioned embodiment are given the same reference numerals, and the explanation thereof will be omitted. This embodiment has a configuration in which a plurality of communication passages 17 are provided to communicate the inner pipe 5 and the outer pipe 9 forming the refrigerant return passage 4. In this case, an insertion plate 19 may be provided within the inner tube 5 in order to bring a plurality of fan-shaped tubes into contact with the outer tube 1.

In this embodiment, since the communication path 17 between the inner tube 5 and the outer tube 9 can be made larger, the flow resistance of the liquid refrigerant can be further reduced, and the heat transport ability can be further improved.

Note that this invention is not limited to the above-described embodiments. For example, the slit 13 formed in the outer tube 9 may be formed in a spiral shape, and in short, any structure that allows communication between the inside and the outside of the outer tube 9 may be used.

[Brief explanation of drawings]

FIG. 1 is a cross-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 cross-sectional view of a heat pipe according to another embodiment, and FIG. Figure and 5th
Each figure is a sectional view of a conventional arch reheat vibrator, and FIG. 6 is a sectional view of a conventional monogroup heat pipe. (Explanation of symbols representing main parts of the drawings) 1... Outer tube 3 Inner tube 4... Refrigerant return path 5... Inner tube 9... Outer tube 11... Groove 13... Slit ( Communication hole) 15.17...Communication path

Claims (1)

[Claims] It has an outer tube and an inner tube inserted into the outer tube, and the inner tube has a double tube structure consisting of an inner tube forming a refrigerant return path and an outer tube forming a steam passage. A groove with a relatively small cross-sectional area is provided on the inner surface extending from the evaporation section to the condensation section, and a communication hole that communicates with the groove is provided on the outer peripheral surface of the evaporation section side and the condensation section side, and the communication hole of the outer tube and A heat pipe characterized in that a communication path is provided between the inner tube and the inner tube.