JPH0731026B2 - heat pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses water as a working fluid and iron, copper, etc., which react with water to generate hydrogen gas, as a material for a container, and a wick.
About the heat pipe of the type that does not have .

In this specification, the word "iron" means
In addition to pure iron, iron alloys such as stainless steel and carbon steel are included. Further, the term “copper” includes copper alloy in addition to pure copper.

[0003]

2. Description of the Related Art For example, a heat pipe in which water is enclosed in an iron container is widely used because of its high strength and its high performance as a hydraulic fluid. Has been done. However, such a heat pipe has a problem that iron and water react with each other to generate hydrogen gas, which deteriorates the performance of the heat pipe in a short time. That is, the generated hydrogen gas diffuses inside the wall of the container in an atomic state and is partly discharged outside the container at a constant speed, but most of it gradually accumulates in the condensation part inside the container and occupies the condensation part. Therefore, the condensation of steam is hindered and the heat transfer performance of the heat pipe is deteriorated.
Moreover, since this kind of deterioration increases in proportion to time,
The life of the heat pipe is shortened at an accelerated rate. further,
The outer surface of the iron container may be subjected to aluminizing treatment for the purpose of providing corrosion resistance and vacuum brazing of aluminum fins having a brazing layer.In this case, hydrogen gas diffused inside the wall of the container is formed aluminized. Release from the container is blocked by the film.

Therefore, in order to prevent the generation of hydrogen gas and the deterioration of the performance of the heat pipe due to the generation of hydrogen gas, the following methods have been conventionally used.

To suppress the reaction between water and iron by adding an inhibitor to water.

To plate a metal such as copper on the inner surface of an iron container.

Providing a hydrogen storage material in the container.

In order to connect the inside and the outside of the container,
A linear hydrogen permeable member consisting of d is provided (Jitsuko Sho 56
-142 gazette), Pd which has good hydrogen permeability in the condensation part.
(See Japanese Utility Model Application Laid-Open No. 50-49064).

However, even with the above method, the generation of hydrogen gas could not be suppressed. Further, in the case of the above-mentioned method, the storage or permeation of hydrogen gas could not catch up with the generation of hydrogen gas which further increases during use at high temperature. Therefore, even with the above methods, it was not possible to sufficiently suppress the performance deterioration of the heat pipe.

By the way, in order to solve the above problems,
For heat pipes with a wick
Metal that reacts with hydrogen gas
Those formed of oxides are known (Shokaisho 6
2-29568). However, this heat
The pipe, the metal oxide is a cylindrical wick forms
And the outer surface is in contact with the inner surface of the container.
Since it is mounted on the inner wall of the antenna, metal oxides and hydrogen
The contact area with the gas becomes small, and the reaction efficiency with hydrogen gas
Is not enough, and hydrogen gas should be returned to water promptly.
I can't. Moreover, it is described in Jitsukai Sho 62-29568.
What is listed is a heat pipe with a wick
It was assumed that a part of the wick was metal oxide.
Since it is made of a material, its manufacturing is troublesome.

The object of the present invention is to solve the above problems,
It is to provide a heat pipe that does not deteriorate in performance over a long period of time and is inexpensive.

[0012]

The heat according to the present invention
Pipe, water is used as the working fluid, and in the form of heat pipe having no is used Rutotomoni wick which reacts with water as a container for the material to generate hydrogen gas, the condensation portion of the container, the hydrogen It is characterized in that a substantially spherical porous sintered body made of an oxidant that oxidizes gas and returns it to water is arranged.

In the above, as the material of the container,
Iron or copper such as carbon steel or stainless steel is used.

In the above, as the oxidizing agent for oxidizing the hydrogen gas to return it to water, it is preferable to use an agent which causes a reaction of H ₂ + MO → H ₂ O + M (M represents a metal element). Among these, when put in the heat pipe, the cost is low without adversely affecting the performance of the heat pipe.
It is preferable to use Cu ₂ O or CuO from the viewpoint that the hydrogen gas oxidation effect is excellent. The amount of oxidant must be sufficient to oxidize the hydrogen generated in the heat pipe. For example, in a 3 m long heat pipe in which water is enclosed in an iron container, a maximum of 2 cc of hydrogen gas is generated per day even if an anticorrosive film is formed on the inner surface of the container. Therefore, if this heat pipe is used for 10 years, 30 g of CuO (0.32
mol or more) should be placed in the container.

[0015]

According to the heat pipe of the present invention, the hydrogen gas produced by the reaction between water and the container is oxidized by the oxidant and returns to water, and is not accumulated in a gas state in the condensing section. Moreover, since the oxidizing agent is a substantially spherical porous sintered body, the contact area with hydrogen gas increases. further,
Condensed heat pipe with no wick
An oxidizer consisting of a substantially spherical porous sintered body is placed inside
The heat pipe is easy to manufacture.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

[0017] In FIG. 1, a heat pipe (1), Conwy
STB which is a type of heat pipe without a hook
Container body consisting of 35 long pipe (2a) and STB35 short pipe (2b) welded to one end of the long pipe (2a)
(2) and SS41 welded to one end of the container body (2)
Pure water as a working fluid (not shown) is placed in a container (5) consisting of an end cap (3) made of SS41 and an end cap (SS) made of SS41 which is welded to the other end of the container body (2).
Is filled so as to fill 20% of the entire inner volume of the container (5).

In the short pipe (2b), a substantially spherical porous oxidant sintered body (6) made of CuO is arranged. This weight is 30 g. The oxidizer porous sintered body (6) is fixed to the end of a fixing rod (7) fixed to the end cap (3) and is separated from the inner surface of the container (5). />

In this heat pipe (1),
The container body (2) may consist of a single pipe.

This heat pipe (1) is a short pipe (2b)
The side is used as the condenser (8) and the opposite side is used as the evaporator (9). Then, the hydrogen gas generated by the reaction between the working fluid, water, and the container (5) is the oxidizer-made porous sintered body (6).
Oxidized by and undergoes the next reaction to return to water.

CuO + H ₂ → Cu + H ₂ O Next, the tests conducted to evaluate the performance of the heat pipe according to the present invention will be described.

First, a STB35 long pipe (2a) having a diameter of 31.8 mm, a wall thickness of 4.5 mm and a length of 2900 mm and a diameter of 3
Short pipe (2b) with 1.8mm, wall thickness of 4.5mm and length of 100mm
Were prepared, brushed on the inner surfaces thereof with a wire brush, and then degreased with acetone. Then attach the fixing rod to one side of the end cap (3).
After fixing (7) and further fixing the oxidant porous sintered body (6) made of CuO to the tip, weld the end cap (3) to one end of the short pipe (2b) and pipe
The other end of (2b) was welded to one end of the long pipe (2a). afterwards,
The end cap (4) with a nozzle was welded to the other end of the long pipe (2a) to form a container (5). Then, pure water was sealed in the container (5) by a known method. Thus, the heat pipe (1) was manufactured.

As shown in FIG. 2, half of the heat pipe (1) on the condenser (8) side is covered with a water cooling jacket (11), and an electric heater is provided around the half on the evaporator (9) side. The wire (12) was wound and covered with a heat insulating material (13) from above. Then, the heat pipe (1) was placed in a state of being tilted by 6 degrees with respect to the horizontal plane so that the end on the side of the condensing part (8) was on the top. In this state, cooling water is supplied and circulated in the water cooling jacket (11) to cool half of the heat pipe (1), while the other half is heated by the electric heater wire (12).
While heating to ℃, 20mm from the tip of the condensing part (8) (P
The temperature of 1) and the temperature of the point (P2) at the center of the length outside the water cooling jacket (11) are measured every predetermined time, and the temperature difference (ΔT) between both points (P1) and (P2) is measured. ) Was measured. At this time, the heat transfer amount from the evaporation section (9) to the condensation section (8) is always 40
It was set to 00W. The result is shown in FIG.

For comparison, a heat pipe having substantially the same construction as that of the above-mentioned embodiment except that an oxidizing agent was not placed in the condensing section was used, and the heat pipe was used under the same conditions as above. A performance evaluation test was conducted. The result is shown in FIG.

As is apparent from the graph shown in FIG. 3, in the product of the present invention in which the oxidant porous sintered body (6) was placed in the condensing part (8), the temperature difference ( ΔT)
Is about 3 ° C., indicating that the heat transfer performance is still good. On the other hand, in the comparative product, the temperature difference (ΔT) becomes considerably large, and it can be seen that the heat transfer performance deteriorates in a short time.

FIG. 4 shows another embodiment of the present invention. 4, the same parts and parts as those shown in FIG. 1 are designated by the same reference numerals.

In the heat pipe (20) shown in FIG. 4,
Both ends of the movement prevention rod (21) orthogonal to the axis of the short pipe (2b) are fixed to the part of the inner surface of the short pipe (2b) near the long pipe (2a), and the ends of the movement prevention rod (21) are closer to the end. A substantially spherical porous oxidizer sintered body (22) made of CuO is placed on the side of the cap (3). The oxidant porous sintered body (22) is prevented from moving to the long pipe (2a) side by the movement preventing rod (22).

[0028]

According to the heat pipe of the present invention, since a porous sintered body made of an oxidizing agent that oxidizes hydrogen gas and returns it to water is arranged in the condensing portion, water as a working fluid and a container are used. Even if and react to generate hydrogen gas, this hydrogen gas is oxidized by the oxidant and returns to water. Therefore, the deterioration of the heat pipe performance due to the generated hydrogen gas can be suppressed. Moreover , by disposing an oxidizing agent in an amount capable of oxidizing the total amount of hydrogen gas that is expected to be generated, it is possible to reliably suppress the performance deterioration for a long period of time. Further, even if the amount of hydrogen gas generated increases at the time of use at high temperature, it can be promptly returned to water, and the performance deterioration of the heat pipe can be suppressed. In addition, a porous sintered body in which the oxidizing agent has a substantially spherical shape
Therefore, the contact area with hydrogen gas increases and the reaction efficiency with hydrogen gas improves. Therefore, the generated hydrogen gas can be quickly returned to water. In addition, wick
It is a type of heat pipe without a porous sintered body
The oxidant, which consists of
Manufacturing of pipes becomes easy.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a heat pipe according to the present invention with a middle part omitted and a part cut away.

2 is a partially cutaway front view showing a method of a performance evaluation test of the heat pipe shown in FIG. 1. FIG.

FIG. 3 is a graph showing the results of the performance evaluation test of the heat pipe shown in FIG. 1 together with the results of the comparative product.

FIG. 4 is a partial vertical sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Heat Pipe 5 Container 6 Oxidizing Porous Sintered Body 8 Condensing Part 20 Heat Pipe 22 Oxidizing Porous Sintered Body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuichi Furukawa 6224, Kaiyamacho, Sakai City, Osaka Prefecture Showa Alminium Co., Ltd. (72) Inventor Issei Noguchi 6224, Kaiyamacho, Sakai City, Osaka Showa Al Within Minium Co., Ltd. (56) References: 62-29568 (JP, U)

Claims (1)

[Claims] 1. A water is used as the working fluid, and Conte <br/> reacts with water as a material for Na is intended to generate hydrogen gas is used in the form without a Rutotomoni wick heat
A heat pipe characterized in that a substantially spherical porous sintered body made of an oxidizer that oxidizes hydrogen gas and returns it to water is arranged in the condensing part of the container.