JP2002277178A - Heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pipe capable of performing a normal thermal transfer from a heating fluid in an inner pipe to a working fluid in an outer pipe and realizing a superior heating efficiency even in the case that either a curved segment or a part of the inner pipe is floated up from a liquid surface of the working fluid. SOLUTION: An inner pipe 16 for flowing a heating fluid L1 is passed through in an outer pipe 12. Working fluid 12 having a low boiling point is stored in the outer pipe 12, and at the same time a residual space is kept at a vacuum state. A mesh-like covering member 21 having a capillary tube phenomenon function is arranged at an outer circumferential surface of the inner pipe 16, and the working fluid L2 in the outer pipe 12 is guided to an entire outer circumferential surface of the inner pipe 16 through the covering member 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe used as a heating source, for example.

[0002]

2. Description of the Related Art In a conventional heat pipe of this type, a middle pipe is provided inside an outer pipe. A working fluid having a low boiling point is accommodated in the outer pipe, and the remaining space is maintained in a vacuum state. When a heating fluid such as hot water flows through the middle pipe, the working fluid in the outer pipe evaporates, and the steam is cooled by the outer wall of the outer pipe and condenses again. The outer pipe is heated and radiates heat.

[0003]

In this heat pipe, the middle pipe may be curved in the outer pipe. For example, when the middle pipe is inserted into the outer pipe during assembly, the holding pipe is pressed into the insertion hole from the outside of the end plate with the middle pipe inserted into the insertion holes formed in the end plates at both ends of the outer pipe. By doing so, the middle pipe is held between both end plates. In this case, the middle pipe may be gradually pushed into the outer pipe with the press-fitting of the holding cylinder, and the middle pipe may be bent in the outer pipe. When the curved portion is generated in this way, when the working fluid is subsequently injected into the outer pipe, the curved portion of the middle pipe floats above the level of the working fluid in the outer pipe.

Also, when using a heat pipe,
When the heating fluid is flowed into the middle pipe, the middle pipe is heated faster than the outer pipe and expands.Therefore, the middle pipe has a curved portion in the outer pipe, and the curved portion is the liquid level of the working fluid. May emerge from Further, when the heat pipe is installed in an inclined state in a greenhouse or the like, the middle pipe is not immersed in the working fluid in the outer pipe over its entire length, and the upper end side of the middle pipe is a liquid of the working fluid. It is in a state of rising from the surface.

[0005] As described above, when the curved portion or a part of the middle pipe rises from the level of the working fluid, heat transfer from the heating fluid in the middle pipe to the working fluid in the outer pipe is not normally performed. For this reason, there has been a problem that the heating efficiency of the heat pipe is greatly reduced.

The present invention has been made by paying attention to such problems existing in the conventional technology. The purpose is that even if the curved portion or a part of the middle pipe rises from the level of the working fluid, heat transfer from the heating fluid in the middle pipe to the working fluid in the outer pipe can be performed normally, An object of the present invention is to provide a heat pipe that can exhibit good heating efficiency.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, according to the first aspect of the present invention, a middle pipe for flowing a heating fluid into the outer pipe is provided. A working fluid with a low boiling point is accommodated inside the
In a heat pipe in which the remaining space is kept in a vacuum state, means having a capillary effect function is provided on the outer peripheral surface of the middle pipe.

Therefore, according to the first aspect of the present invention, when assembling or using the heat pipe, the curved portion generated in the middle pipe rises from the level of the working fluid in the outer pipe, or Due to the arrangement of the heat pipe in the inclined state, even if a part of the middle pipe rises from the level of the working fluid, the heating efficiency does not decrease. That is, even when the curved portion or a part of the middle pipe rises from the level of the working fluid, the working fluid is guided to the entire outer peripheral surface of the middle pipe via the means having the capillary action function.
Therefore, heat transfer from the heating fluid in the middle pipe to the working fluid in the outer pipe can be performed normally, and the working fluid can be evaporated over the entire length of the middle pipe. Can be demonstrated.

According to a second aspect of the present invention, in the first aspect of the present invention, the means comprises a mesh-shaped member. Therefore, according to the second aspect of the present invention, the structure of the means having the capillary action is simple, and the working fluid is applied to the entire outer peripheral surface of the middle pipe via the mesh-like member which easily causes the capillary action. Can be effectively derived.

According to a third aspect of the present invention, in the first or second aspect of the invention, the means is provided over substantially the entire length of the middle pipe. Therefore, according to the third aspect of the present invention, even if a curved portion is formed in any part of the middle pipe, or even if the middle pipe is inclined so that any end side thereof is upward, It is possible to reliably prevent the heating efficiency from being reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, in a heat pipe 11 of this embodiment, an outer pipe 12 is formed of a metal material in a cylindrical shape, and end plates 13 are caulked at both ends thereof via seal rings 14. It is fixed. A middle pipe 16 for flowing a heating fluid L1 such as hot water is inserted into the insertion hole 15 of the both end plates 13 through the holding cylinder 17 and the seal ring 18 so as to extend in the longitudinal direction through the inside of the outer pipe 12. Supported. The inner pipe 16 is formed in a cylindrical shape from a metal material, and its outer peripheral surface is subjected to alumite processing. The outer pipe 12, the middle pipe 16 and the end plate 13 are made of aluminum or aluminum alloy.

A small hole-shaped opening 19 is formed through the both end plates 13. A working fluid L2 having a low boiling point, such as Freon or ammonia, is injected and stored in the outer pipe 12 through the opening 19, and the remaining space is evacuated to be kept in a vacuum state. After the working fluid L2 is injected and evacuated, the openings 19 of the end plates 13 are opened.
The ball 2 made of the same metal material as the outer pipe 12
0 are fitted and fixed, and their openings 19 are closed.

As shown in FIG. 1 to FIG.
A covering member 21 in the form of a mesh such as a wire net or fiber as a means having a capillary action is fitted and fixed to the outer peripheral surface of the outer pipe 12 over the entire length of the outer pipe 12. Also,
The covering member 21 also serves as a cushioning material. Further, when the covering member 21 is made of a non-conductive material,
Functions as an insulating material. Then, as shown in FIGS. 1 and 4, the curved portion 16 a formed on the middle pipe 16 or a part 16 b of the middle pipe 16 is used as the working fluid
2, the working fluid L2 is guided to the entire outer peripheral surface of the middle pipe 16 by the capillarity via the covering member 21.

Next, the operation of the heat pipe 11 configured as described above will be described. Well, this heat pipe 11
When the heating fluid L1 such as hot water flows through the middle pipe 16 in a state in which the heating fluid L1 is installed in a greenhouse or the like, the working fluid L2 in the outer pipe 12 evaporates, and the steam is removed from the outer pipe 1
It is cooled by the peripheral wall of No. 2 and condenses again. Then, the heat generated at the time of the condensation heats the outer pipe 12 and dissipates heat into a greenhouse or the like. Therefore, the inside of the greenhouse and the like can be maintained at a predetermined temperature state.

When assembling the heat pipe 11, when the middle pipe 16 is inserted through the outer pipe 12, the insertion holes 1 formed in both end plates 13 of the outer pipe 12 are formed.
While the middle pipe 16 is inserted through 5, the seal ring 18 and the holding cylinder 17 are pressed into the insertion hole 15 from outside the end plate 13. In this case, the middle pipe 1
6 is gradually pushed into the outer pipe 12, and as shown by a chain line in FIGS.
May have a curved portion 16a. As described above, when the curved portion 16a is formed in the middle pipe 16, when the working fluid L2 is subsequently injected into the outer pipe 12, the curved portion 16a of the middle pipe 16 floats above the level of the working fluid L2. Become.

Even when the heat pipe 11 is used, when the heating fluid L1 flows through the middle pipe 16, the middle pipe 16 is heated faster than the outer pipe 12 and expands. As shown in the figure, a curved portion 16a is formed in the middle pipe 16 in the outer pipe 12, and the curved portion 16a
May rise from the level of the working fluid L2.

Further, as shown in FIG. 4, when the heat pipe 11 is installed in an inclined state in a greenhouse or the like, the middle pipe 16 is immersed in the working fluid L2 in the outer pipe 12 over the entire length. Without this, a part 16b on the upper end side of the middle pipe 16 floats up from the level of the working fluid L2.

As described above, the curved portion 16a of the middle pipe 16
Alternatively, when the part 16b rises from the level of the working fluid L2, the heating fluid L1 flowing in the middle pipe 16 is not effectively used, and the working fluid L2 is evaporated in the entire length direction of the middle pipe 16. Disappears. For this reason, the heating efficiency of the heat pipe 11 may be significantly reduced.

However, in the heat pipe 11, a mesh-shaped covering member 21 having a capillary effect is fitted on the outer peripheral surface of the middle pipe 16. Therefore, even when the curved portion 16a or a part 16b of the middle pipe 16 rises from the level of the working fluid L2, the working fluid L2 is guided to the entire outer peripheral surface of the middle pipe 16 via the covering member 21. Therefore, the heating fluid L1 in the middle pipe 16
, The heat is transferred to the working fluid L2 in the outer pipe 12 satisfactorily, the working fluid L2 can be evaporated over the entire length of the middle pipe 16, and the outer pipe 12 can be efficiently heated. , A high heat radiation amount can be obtained.

Further, when the heating fluid L1 flows through the middle pipe 16 when the heat pipe 11 is used, the middle pipe 16 is heated and expanded faster than the outer pipe 12, and the middle pipe 16 has a curved portion 16a. May occur in a sagging state. In this case, since the covering member 21 which also serves as a cushioning material or an insulating material or both is fitted on the outer periphery of the middle pipe 16, the middle pipe 16 is attached to the outer pipe 1.
2 without direct sliding contact with the inner peripheral surface of
Slidable contact with each other.

As a result, the middle pipe 16 is in direct sliding contact with the inner peripheral surface of the outer pipe 12, and the sliding contact is scratched and the alumite is peeled off. Corrosion current flows through the sliding contact. No. Thus, the heat pipe 11 can be used for a long time without causing a hole in the middle pipe 16 during use.

Therefore, according to this embodiment, the following effects can be obtained. (1) In this heat pipe 11, the outer pipe 1
A medium pipe 16 for flowing the heating fluid L1 into the inside 2 is provided. A working fluid L2 having a low boiling point is accommodated in the outer pipe 12, and the remaining space is maintained in a vacuum state. A means 21 having a capillary action function is provided on the outer peripheral surface of the middle pipe 16.

Therefore, when assembling or using the heat pipe 11, the curved portion 16 a formed on the middle pipe 16 rises above the level of the working fluid L 2 in the outer pipe 12, or the heat pipe 11 is inclined. With this arrangement, even when a part of the middle pipe 16 rises above the level of the working fluid L2, the heating efficiency does not decrease. That is, even when the curved portion 16a or a part of the middle pipe 16 rises from the level of the working fluid L2, the working fluid L2 is guided to the entire outer peripheral surface of the middle pipe 16 via the means 21 having a capillary effect function. Therefore, the middle pipe 16
Heat transfer from the inner heating fluid L1 to the working fluid L2 in the outer pipe 12 can be performed normally, and good heating efficiency can be exhibited.

(2) In the heat pipe 11, the means is constituted by a mesh-shaped covering member 21. For this reason, the structure of the means having a capillary action is simple, and the working fluid L2 can be effectively guided to the entire outer peripheral surface of the middle pipe 16 via the mesh-shaped covering member 21.

(3) In the heat pipe 11, the mesh-shaped covering member 21 is provided over substantially the entire length of the middle pipe 16. Therefore, the middle pipe 1
6, even when the curved portion 16a is formed at any portion, or when the middle pipe 16 is inclined and disposed so that any end side thereof is upward, it is possible to reliably prevent the heating efficiency from being lowered. it can.

(4) In the heat pipe 11, the mesh-shaped covering member 21 is used as at least one of a buffer material and an insulating material. For this reason, even when the curved portion 16 a hangs down on the middle pipe 16, the middle pipe 16 does not make sliding contact directly with the inner peripheral surface of the outer pipe 12, but makes sliding contact via the covering member 21. . Therefore, it is possible to prevent the sliding contact portion of the middle pipe 16 from being damaged, and it is possible to prevent the corrosion current from flowing through the sliding contact portion, thereby preventing the possibility that the middle pipe 16 is perforated. can do.

(Second Embodiment) Next, a second embodiment of the present invention will be described focusing on parts different from the first embodiment.

The heat pipe 1 according to the second embodiment will now be described.
In FIG. 1, as shown in FIG. 5, a mesh-shaped covering member 21 having a capillary effect is fitted and fixed to a part 16b on one end side of the middle pipe 16 in the outer pipe 12. Therefore, also in this embodiment, when the middle pipe 16 is arranged in an inclined manner, the one end where the covering member 21 is provided may be located upward. Therefore, even if the heat pipe 11 is arranged in an inclined state and the part 16 b of the middle pipe 16 rises from the level of the working fluid L 2, the working fluid L 2 is transferred to the entire outer peripheral surface of the middle pipe 16 via the covering member 21. Can be led to.

Therefore, according to the second embodiment, the same effects as the effects (1), (2) and (4) of the first embodiment can be obtained. (Modification) This embodiment can be modified and embodied as follows.

In each of the above-described embodiments, as a means having a capillary action function, a synthetic resin having an open-cell foaming function is applied to the outer peripheral surface of the middle pipe 16 by heating. That is, the middle pipe 1 coated with the above synthetic resin
6 is inserted into the outer pipe 12 and heated and foamed. Then, the inside of the outer pipe 12 is evacuated, and the working fluid L2 is injected into the outer pipe 12. Even with such a configuration, it is possible to obtain substantially the same effects as those of the above-described embodiments.

In each of the above embodiments, as means having a capillary action, a large number of fine irregularities are formed on the entire or a part of the outer peripheral surface of the middle pipe 16. With this configuration, the number of parts is reduced, and the configuration is simplified.

(Other technical ideas) The technical ideas other than the claims grasped from the embodiment are as follows. (1) The heat pipe according to any one of claims 1 to 3, wherein the means having a capillary action function is made of an insulating material.

In this way, it is possible to prevent the formation of holes due to corrosion current. (2) The heat pipe according to any one of claims 1 to 3, wherein the means having a capillary action function is provided in substantially a half part of the length direction of the middle pipe.

This is convenient when the heat pipe is installed at an angle.

[0036]

As described above, in the present invention, the present invention has an excellent effect that good heating efficiency can be exhibited even when the middle pipe rises from the level of the working fluid. I do.

[Brief description of the drawings]

FIG. 1 is an essential part cross-sectional view showing a heat pipe of a first embodiment.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a partial front view showing a middle pipe in the heat pipe of FIG. 1;

FIG. 4 is an essential part cross-sectional view showing the heat pipe of FIG. 1 in an inclined state;

FIG. 5 is an essential part cross-sectional view showing the heat pipe of the second embodiment in an inclined state.

[Description of Signs] 11: heat pipe, 12: outer pipe, 13: end plate, 1
6 ... medium pipe, 16a curved portion, 16b ... part, 21 ... mesh-shaped covering member as means having a capillary action function, L1: heating fluid, L2 ... working fluid.

Claims (3)

[Claims] 1. A heat pipe in which a middle pipe for flowing a heating fluid is passed through an outer pipe, a working fluid having a low boiling point is accommodated inside the outer pipe, and a remaining space is kept in a vacuum state. A heat pipe, characterized in that a means having a capillary action function is provided on the outer peripheral surface of the middle pipe. 2. The heat pipe according to claim 1, wherein said means comprises a member having a mesh shape. 3. The heat pipe according to claim 1, wherein the means is provided over substantially the entire length of the middle pipe.