JPH04124591A - Manufacturing method of heat pipe heat exchanger - Google Patents

Abstract

PURPOSE:To improve operability and reduce the value of thermal resistance nicely by a method wherein a heat transfer member, having a thermal expansion coefficient higher than the same of the sealed vessel of a heat pipe, is used and the sealed vessel is expanded by the vapor pressure of operating liquid in the sealed vessel while the sealed vessel is contacted closely with the heat transfer member by the plastic deformation at that time. CONSTITUTION:A heat transfer member 12 is formed of a material having a thermal expansion coefficient higher than the same of a sealed vessel 14. A heat pipe 10 is inserted into the inserting hole 18 of the heat transfer member 12 and, thereafter, the whole of a heat exchanger is heated at a temperature T to expand the sealed vessel 14 by the vapor pressure of the operating liquid 16 and contact said vessel 14 closely with the inner wall of the inserting hole 18 of said vessel 14 by the plastic deformation in this case. Thereafter, the whole of the heat pipe heat exchanger is cooled. The heat exchanger is contracted as a whole by this cooling, however, the thermal expansion coefficient of the heat transfer member 12 is higher compared with the sealed vessel 14 and, therefore, the heat transfer member 12 is contracted largely than the sealed vessel 14 whereby the closely contacting condition between the sealed vessel 14 and the heat transfer member 12 can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-vib heat exchanger in which a heat transfer member is arranged around a heat pipe, and a method for manufacturing the same.

[Conventional technology]

Heat pipes have a relatively simple structure in which a working fluid is sealed in a closed container, and can transfer a large amount of heat with a small temperature difference, so they have been used as heat exchangers in various fields in recent years. A heat exchanger using such a heat pipe generally has a heat transfer member in which radiation fins are formed around the outer periphery of a heat vibe.

In such a heat pipe heat exchanger, the following various methods have been conventionally adopted as means for reducing the thermal resistance value between the heat pipe and the heat transfer member.

■ An insertion hole with a diameter slightly smaller than the outer diameter of the heat vibrator is formed in the heat transfer member, and the heat vibrator is press-fitted into this insertion hole to bring the heat vibrator and the heat transfer member into close contact (press-fitting method).

■ Form an insertion hole in the heat transfer member with a diameter slightly larger than the outer diameter of the closed container for heat pipes, insert the container into the insertion hole, and mechanically expand the container using a mandrel or hydraulic pressure. After the container is brought into close contact with the heat transfer member, the container is processed into a heat vibrator and the working fluid is sealed therein (tube expansion method).

■ An insertion hole with a diameter slightly larger than the outside diameter of the heat vibrator is formed in the heat transfer member, the heat pipe is inserted into this insertion hole, and the gap between the two is filled with highly thermally conductive resin or solder (filling method).

■ An insertion hole with a diameter slightly larger than the outside diameter of the heat vibrator is formed in the heat transfer member, and after inserting the heat pipe into this insertion hole, they are heated and heat is transferred by the vapor pressure of the working fluid in the sealed container. The member and the heat vibrator are brought into close contact (heating tube expansion method). An example of applying a heat vibrator manufactured in this way to the shaft of a motor is disclosed in Japanese Patent Application Laid-Open No. 59-1104.
This is shown in Publication No. 32.

[Problem to be solved by the invention]

However, the conventional heat pipe heat exchanger as described above has the following disadvantages.

In (2) (press-fitting method), the work of adjusting the heat vibrator itself is complicated and difficult.

■(Pipe expansion method), injection of lubricant during pipe expansion work,
Removal and filling of hydraulic fluid after pipe expansion takes a lot of effort, resulting in poor work efficiency.

In (filling method), the filling operation requires a large cost. In addition, the thermal conductivity of the filler is generally lower than that of heat transfer members and sealed containers for heat pipes, and filling the filler increases the interface between the heat vibrator and the heat transfer member, reducing the thermal resistance value. becomes a hindrance.

■ (Heating tube expansion method) is superior in terms of workability, but the coefficient of thermal expansion of the heat transfer member is generally lower than that of the sealed container for heat pipes, so even if the two are in close contact during heating, once they reach room temperature, A gap will be formed at the boundary between the two.

[Purpose of the invention]

The present invention has been made in order to solve each of the above-mentioned problems, and aims to provide a heat pipe heat exchanger that can satisfactorily reduce the thermal resistance value and has excellent workability, and a method for manufacturing the same. purpose.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a heat pipe heat exchanger according to the present invention, which includes a heat vibrator formed by sealing a working fluid in a closed container;
and a heat transfer member that surrounds the heat vibrator with some margin; constructed by bringing the closed container and the heat transfer member into close contact through plastic deformation based on tube expansion of the closed container due to the vapor pressure of the working fluid. has been done. Furthermore, the method for manufacturing a heat pipe heat exchanger according to the present invention includes:
A heat vibrator having a predetermined outer diameter is processed using a metal having a tenth coefficient of thermal expansion; Processing a heat transfer member having an insertion hole with a predetermined inner diameter larger by a predetermined dimension; Inserting the heat vibrator into the insertion hole of the heat transfer member; Plastic deformation is applied to the heat vibrator based on the vapor pressure and thermal expansion by heating the vibrator so that the vapor pressure does not exceed the bursting strength value of the vibrator, and this plastic deformation causes the heat vibrator to become attached to the inner wall of the insertion hole of the heat transfer member. Each process involves bringing the material into close contact with the material.

[Effect]

As described above, in the present invention, since the closed container is plastically deformed and brought into close contact with the heat transfer member, the heat vibrator and the heat transfer member can be brought into close contact with each other by an extremely easy operation. In addition, since the heat transfer member is made of a material with a higher coefficient of thermal expansion than the sealed container, even when the manufactured heat exchanger is cooled, the heat transfer member will shrink more than the sealed container. The state of close contact between the outer wall of the heat vibrator and the inner wall of the heat transfer member is permanently guaranteed.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1(A) shows the configuration of the heat pipe heat exchanger before final processing is completed. This heat pipe heat exchanger includes a heat vibrator 10 and a heat pipe 10.
The heat transfer member 12 surrounds the heat transfer member 12.

The heat vibe 10 includes a cylindrical sealed container 14 and a predetermined amount of working fluid 16 sealed within the sealed container 14 . The material of the sealed container 14 is copper, and the hydraulic fluid 16
Water is used as the water. Note that the amount of the working fluid 16 is such that it is all vaporized at a temperature T, which will be described later.

In addition to the above-mentioned copper-water, combinations of the sealed container 14 and the working fluid 16 include copper-fluorocarbon, aluminum-fluorocarbon,
Possible options include aluminum-ammonia, stainless steel-fluorocarbon, and stainless steel-ammonia, but considering the strength of the container and the high-temperature properties of the working fluid, a combination of aluminum and ammonia is more practical than the above-mentioned combination of steel and water. It is.

The heat transfer member 12 is made of a material having a higher coefficient of thermal expansion than the hermetic container 14 . For example, when copper is used as the material for the sealed container 14, aluminum 9. Copper alloy 2 alloy steel, magnesium, lead.

Zinc, tin, or their alloys are used. Also, airtight container 1
When the material in step 4 is aluminum, magnesium, zinc, lead, or an alloy thereof is used.

Heat-absorbing fins 12a are integrally molded at the lower part of the outer periphery of the heat transfer member 12, and heat-radiating fins 12b are integrally molded at the upper part.
Heat absorbed from the heat absorption fins 12a is transmitted to the heat vibrator 10, and this heat is released to the outside from the heat radiation fins 12b.

An insertion hole 18 into which the heat vibrator 10 is inserted is formed in the center of the heat transfer member 12 . This insertion hole 18 has an inner diameter slightly larger than the outer diameter of the closed container 14 .

After inserting the heat vibrator 1O into the insertion hole 18 of the heat transfer member 12, the entire heat exchanger is heated to a temperature T, and the heat exchanger is heated as shown in FIG. 1(B).
The closed container 14 is expanded by the vapor pressure of the working fluid 16, and the container 14 is brought into close contact with the inner wall of the insertion hole 18 by plastic deformation at that time.

After that, the entire heat pipe heat exchanger is cooled down.

Due to this cooling, the heat exchanger contracts as a whole, but since the heat transfer member 12 has a higher coefficient of thermal expansion than the closed container 14, the heat transfer member 12 contracts more than the closed container 14,
The close contact between the closed container 14 and the heat transfer member 12 is maintained.

Next, the heating temperature T1 of the heat pipe heat exchanger in the above embodiment and the sealed amount X of the working fluid 16 will be considered.

The heating temperature T is a temperature at which the vapor pressure of the working fluid 16 in the closed container 14 does not exceed the bursting pressure of the closed container 14. For example,
The outer diameter of the copper sealed container 14 is 9.52vw, and the wall thickness is 0.
．． 34 mm, and the effective length is 100 mm, the temperature T is 299°C. As shown in FIG. 2, this is based on the relationship between the vapor pressure PI (solid line) of water, which is the working fluid 16, with respect to the heating temperature T, and the bursting pressure Pt (dashed line) of the steel pipe with respect to the heating temperature T. Both lines P+, P
This is to prevent the closed container 14 from bursting by setting the heating temperature T to a value lower than the point where the curves g intersect (limit temperature 304° C.).

When the amount X of the hydraulic fluid 16 is calculated for the heating temperature T set in this manner, the amount X of the hydraulic fluid 16 is 3.0 g or less. This is the amount of saturated liquid that does not remain when the limit temperature is 304°C, and the internal volume of the closed container 14 (61.4 d
) divided by the specific volume of saturated steam (20,3 cd).

If the sealed amount
The vapor pressure at heating temperature T=299℃~310℃ is 1℃
However, since the value is very small at 11571 kgf/d, the heating temperature T can be easily adjusted. Also, 2.
The amount of the hydraulic fluid 16 of 8 g is the internal volume R of the sealed container 14.
(61.4 cm), which is a sufficient amount for use in the bottom heat mode of the heat vibrator.

On the other hand, when the amount
Figure curve! As shown by (--dotted chain line), the temperature changes extremely rapidly and the sealed container structure 4 becomes easily destroyed, making it extremely difficult to put it into practical use. This means that when the working fluid in the Heat Vibe is increased and the heating temperature is raised near the limit temperature (304°C), the outer diameter of the heat pipe will suddenly increase along the straight line that indicates the limit temperature. It depends on the facts.

When using the heat pipe heat exchanger manufactured as described above, the heat of the object to be cooled is transferred to the heat absorption fins 1 of the heat transfer member 12.
2a to the heat vibrator 10. Due to this heat, the working fluid 16 inside the heat vibe IO evaporates, and heat is transferred to the other end (upper part) of the heat vibe IO. The transferred heat is released from the radiation fins 12b of the heat transfer member 12,
The evaporated gas is condensed, and the condensed working fluid 16 is returned to the heat receiving part (lower part) of the heat vibe 10. By repeating such operations, heat exchange is performed between the object to be cooled and the heat radiation atmosphere (air, cooling medium such as water) via the heat vibrator IO.

At this time, since the heat vibrator 10 and the heat transfer member 12 are in close contact with each other, there is almost no heat loss at the boundary between them. Become big.

〔Effect of the invention〕

As explained above, in the present invention, a heat transfer member having a higher coefficient of thermal expansion than the sealed container of the heat vibrator is used, the sealed container is expanded by the vapor pressure of the working fluid in the sealed container, and the plastic deformation at that time causes the sealing. Since the container and the heat transfer member are brought into close contact with each other, the workability is improved and the thermal resistance value can be favorably reduced.

[Brief explanation of drawings]

FIGS. 1A and 1B are cross-sectional views showing the configuration and manufacturing process of a heat pipe heat exchanger according to an embodiment of the present invention. FIG. 2 is a graph for explaining the effect of the embodiment. Explanation of symbols 11--Heat vibrator--Heat transfer member--Heat absorbing fin Radiation fin Closed container Working fluid insertion hole 12a, 1 2 b-- 14--...--= 16 −・−・− 18・---111

Claims (2)

[Claims] (1) A heat pipe formed by enclosing a working fluid in an airtight container, and a heat transfer member having a higher coefficient of thermal expansion than the airtight container and surrounding the heat pipe with some margin, and vapor of the working fluid. A heat pipe heat exchanger characterized in that the heat pipe heat exchanger is constructed by bringing the closed container and the heat transfer member into close contact with each other through plastic deformation based on expansion of the closed container due to pressure. (2) A heat pipe having a predetermined outer diameter is processed using a metal having a first coefficient of thermal expansion, and a heat pipe having a predetermined outer diameter is processed using a metal having a second coefficient of thermal expansion larger than the first coefficient of thermal expansion. processing a heat transfer member having an insertion hole with a predetermined inner diameter that is larger than an outer diameter by a predetermined dimension; inserting the heat pipe into the insertion hole of the heat transfer member; The liquid is heated such that the vapor pressure does not exceed the bursting strength value of the heat pipe, and plastic deformation is applied to the heat pipe based on the vapor pressure and thermal expansion, and this plastic deformation causes the heat pipe to A method for manufacturing a heat pipe heat exchanger, characterized in that the heat pipe heat exchanger is brought into close contact with the inner wall of an insertion hole.