JPS6344691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a composite heat pipe for top heating in which the heating portion is located above gravity.

[Prior art and its problems]

In general, a heat pipe is a tubular body with a wick on its inner wall, which is sealed with a working fluid under reduced pressure.One end of this tube serves as a heating section where the working fluid evaporates, and the other end serves as a heat dissipation section where the working fluid condenses. It is a high-performance heat transfer device that performs rapid heat transport associated with the evaporation → condensation cycle of liquid.

The limit of heat transport in this heat pipe depends on the maximum capillary force of the heat pipe. In other words, the maximum amount of heat transport is determined by the amount of working fluid condensed in the heat radiation section that is returned to the heating section due to the capillary force of the heat sink. Accordingly, the maximum heat transport amount also decreases.

In addition, this capillary force is influenced by body forces such as gravity, and when the heating section is located below, the working fluid is sufficiently refluxed to the heating section side due to the action of gravity. In the case of top heat, the working fluid condensed in the heat dissipation section located below is pulled up to the heating section above by the capillary force against gravity, so the amount of return of the working fluid is reduced. Therefore, under top heat conditions, there is a limit to the capillary force of the heat pipe, so the maximum amount of heat transport becomes small, and a long heat pipe is not suitable for practical use.

For this reason, as a means of transporting heat over a long distance in the vertical direction, a long heat pipe has been developed for top heating, which is a composite of a plurality of short heat pipes connected in a straight line along the longitudinal direction.

However, this composite heat pipe has the drawback that a sufficient amount of heat transport cannot be obtained as a whole because the thermal resistance at the connecting portions at the ends of each unit is extremely large.

[Means for solving problems]

In view of these points, the present invention has developed a composite heat pipe for top heat that reduces the thermal resistance at the connecting portions of each unit of the heat pipe and has a compact overall structure.

That is, in the present invention, a plurality of straight tube-shaped heat pipe groups are formed by arranging a plurality of short heat pipe units with wicks on the inner wall surface in a straight line between the heat pipe units of each heat pipe group. This is a composite heat pipe for top heating in which the separators are shifted in position and bundled together, and the joints of the plurality of heat pipe groups are joined together via a brazing material.

[Examples and effects]

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

Figure 1 shows an embodiment of the present invention, in which copper,
A wick 4 is installed on the inner wall of a short metal pipe (tubular body) made of aluminum or other material with excellent thermal conductivity.
Both ends of the hollow part 3 are closed by welding or the like with a separator 5.
A plurality of independent heat pipe units 7 are formed by sealing the working fluid 6 in a reduced pressure state, and these heat pipe units 7 are arranged in a straight line and each unit is joined by welding or the like. A set of straight heat pipe groups is created. Next, a plurality of straight tube-shaped heat pipe groups are bundled with the separators 5 between the heat pipe units of each heat pipe group shifted, and the joints of the plurality of heat pipe groups are bonded via a brazing material. It was joined together.

The number of straight heat pipe groups to be used is
Figure 1 shows an example of three lines, but the number is not limited to three.
It is also possible to use four or more books.

The wick 4 may be any porous material such as a sintered body, a metal mesh, or a glass fiber, or any material having a capillary action such as a large number of narrow grooves. Further, as the working fluid 6, in addition to water, Freon, alcohol, ammonia, etc., a metal having a relatively low melting point is used.

The manufacturing method for each heat pipe unit is to cut a metal pipe manufactured by extrusion or the like into a predetermined length, close both ends with a separator plate 5 by welding, etc., and then provide an exhaust hole in the wall surface. After injecting the hydraulic fluid 6 from here, the pressure is reduced, or after the pressure is reduced, the hydraulic fluid 6 is injected, and then the exhaust holes are sealed with blind rivets to form independent heat pipe units 7, respectively. In this case, instead of the blind rivet, a thin tube with a ventilation hole may be attached and sealed.

The composite heat pipe for top heat constructed as described above is installed in a device vertically upright or tilted, with the upper end of the heat pipe serving as a heating section A and the lower end serving as a heat dissipating section B. When heating the heating section A on the upper end side in this state, the heating section A on the upper end side of each heat pipe unit 7 will be heated.
The working fluid 6 held therein absorbs latent heat of vaporization and evaporates. The vapor pressure near the heating section a becomes higher than the vapor pressure near the low-temperature heat dissipation section b, and due to this pressure gradient, the steam flows downward to the heat dissipation section b, releases latent heat of condensation, and condenses. This condensed working fluid 6 is pulled up to the heating section a above by the capillary force of the wick 4, where it evaporates again, and the same cycle is repeated thereafter, so that the working fluid 6 is heated at the heating section a in each unit.
This is to transport heat from the heat sink to the heat radiation section b. In FIG. 1, excess working fluid remains at the bottom, but this is not necessarily necessary, as long as the amount of working fluid is within the amount that can be contained in the wick. In this case, since the heat pipe units 7 are arranged alternately, the heat dissipation part b of the heat pipe unit 7 connects the heating part a of the laterally adjacent heat pipe unit 7 with a wide heat transfer area via the brazing material part 10. can do. It goes without saying that if a wick (not shown) connected to the wick 4 is provided below the separator 5, thermal connection can be made through the separator 5, making it even more effective. By making such a connection, the thermal resistance of the connection is low, and heat can be efficiently transported to the heat pipe unit 7 located below. By sequentially transporting heat downward to the heat pipe units 7 in this manner, excellent heat transfer efficiency can be obtained as a whole of the composite heat pipe.

〔effect〕

As explained above, according to the composite heat pipe for top heat according to the present invention, each heat pipe unit is connected to each other by being alternately shifted along the longitudinal direction, so that the upper part of the heat pipe unit is connected to the heating part a, A wide heat transfer area is obtained with the lower part as the heat dissipation part b, and compared to the conventional case in which only the upper and lower ends are used as heat transfer surfaces, thermal resistance is lower and excellent heat transport can be performed as a whole. ,
It has a remarkable effect as a heat transfer mechanism with large height differences. Furthermore, the composite heat pipe for top heat according to the present invention can be assembled by desired combinations of already formed heat pipe units.
Easy to manufacture.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Straight heat pipe group, 3... Hollow part, 4... Wick, 5... Separation plate, 6... Working fluid, 7... Heat pipe unit, A, a... Heating part, B, b... Heat dissipation part, 10... Brazing metal part.

Claims (1)

[Scope of utility model registration request] A set of straight tubular heat pipe groups is formed by arranging a plurality of short heat pipe units with wicks on the inner wall surface in a straight line, and the position of the separator between the heat pipe units of each heat pipe group is determined. This is a composite heat pipe for top heat, in which the joints of a plurality of heat pipes are bundled in a staggered manner and are joined together via a brazing material.