JPS6287788A - Manufacture of heat pipe - Google Patents

Abstract

PURPOSE:To prevent the preclusion of evaporation of operating fluid and improve heat transfer characteristics by a method wherein the operating fluid is heated after pouring and non-condensible gas, generated by heating, is sealed into a nozzle employed for the pouring. CONSTITUTION:A container 1 is provided with a nozzle 2 consisting of a small pipe and the nozzle 2 is sealed temporarily remaining a predetermined length from the container 1 after pouring operating fluid 10 into the container 1. Subsequently, the container 1 is heated to a predetermined temperature to evaporate the operating fluid 10, then, dissolved gas, such as O2, CO2 or the like is separated or deposit on the internal surface of the container 1 is decomposed by heat thereby generating gas. These non-condensible gas enters into the nozzle 2 and the nozzle 2 is filled with non-condensible gas. The container 1 is heated for a predetermined period of time in such manner and, thereafter, the base end of the nozzle 2 at the side of the container 1 is sealed. As a result, the non-condensible gas 11 is removed perfectly and the operating fluid 10 can be supplied whereby a heat pipe, showing expected heat transfer characteristics, may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a heat pipe, and more particularly to a method for enclosing a working fluid in a container while completely excluding non-condensable gases.

As is well known in the art, heat pipes are used to completely exhaust non-condensing gases such as air from the inside of a container if they are made from a sealed pipe or the like.
A condensable fluid such as a low-point fluid (product name) is sealed as a working fluid, and a porous groove structure such as a metal mesh that generates capillary pressure is inserted into the container as a wick. The liquid phase working fluid evaporates due to the heat input from the liquid phase, and the vapor flows to the end where the pressure is lower, and then radiates heat and condenses and liquefies, thereby transporting heat as latent heat of the working fluid. The liquid-phase working fluid is returned to the evaporation section by the capillary pressure generated in the wick. Heat transport in such a heat pipe is
This is done by evaporating the liquid-phase working fluid, and for this purpose, it is necessary to completely eliminate non-condensable gas such as air within the container to facilitate the evaporation of the working fluid.

Conventionally, the above-mentioned requirements for evacuation of non-condensable gas and injection of working fluid have been carried out as follows. In other words, a vacuum pump and a working fluid container are connected via a switching valve mechanism to a container that has been cleaned and removed from oil and other substances that generate gas in a vacuum state. A non-condensable gas such as air is sucked out, and then a small amount of fluid is pumped into the container from the working fluid container to completely eliminate the non-condensable gas from the inside of the container. Next, a specified amount of working fluid is injected into the container, and after the injection is completed, the injection nozzle provided in the container is crushed to seal the container.

Problems to be Solved by the Invention However, as described above, the amount of non-condensable gas in the container inhibits the evaporation of the working fluid and greatly affects the heat transport characteristics. Because the exhaustion of non-condensable gases and the injection of working fluid were completed at this time, dissolved gases such as C2 and GO2 dissolved in the working fluid were separated from the working fluid during heating and formed inside the container, resulting in non-condensable gases. This inevitably led to the problem that it would turn into gas and deteriorate its heat transport properties.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a method that can completely eliminate non-condensable gas within a container and obtain a heat pipe that exhibits desired heat transport characteristics. .

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a container containing a working fluid with a nozzle formed of a thin tube for injecting/sealing the working fluid. A working fluid is injected into the evacuated container through the nozzle, the nozzle is temporarily sealed leaving a protrusion of a predetermined length from the container, and then the container is heated to cool the inside of the container. By evaporating the working fluid, the non-condensable gas in the container enters the nozzle,
The method is characterized in that the nozzle is then permanently sealed at its base end on the container side to remove non-condensable gas from inside the container.

Operation In this invention, operations up to the injection of the working fluid are performed in the same manner as in the prior art. In other words, non-condensable gas such as air is sucked and exhausted from the inside of a pre-washed container using a vacuum pump, and after flushing is performed by blowing working fluid of raw material into the container to further eliminate the non-condensable gas, a specified amount of gas is removed. of working fluid into the container. In the present invention, a nozzle made of a thin tube is provided in the container to perform such evacuation and injection, and after the working fluid is injected, the nozzle is temporarily sealed leaving a predetermined length from the container. In this state, substantially only working fluid exists inside the container. Next, when the container is heated to a predetermined temperature to evaporate the working fluid, gases such as 02 and C02 dissolved in the working fluid are separated from the working fluid, or gases are released due to thermal decomposition of deposits on the inner surface of the container. Occurs. These non-condensable gases are evaporated by further evaporation of the working fluid.
It enters the inside of the nozzle that remains protruding from the container and fills it. After heating the container in this way for a predetermined period of time, the base end of the nozzle on the container side is permanently sealed. The non-condensable gas therein is isolated and excluded from the interior of the container, so that the non-condensable gas is completely excluded from within the container where evaporation and condensation of the working fluid occur.

Example Hereinafter, this invention will be specifically explained based on *Examples.

First, the operation of injecting the working fluid in the present invention is almost the same as the conventional method, and is performed as shown in FIG. In other words, a nozzle 2 is connected to one end of the container (sealed tube) 1 which has been cleaned in advance and a wick has been inserted, and a T-shaped rubber tube is connected to the nozzle 2 via a valve 3. A working fluid container 6 is connected to one end of the rubber tube 4 through a valve 5, and a -C vacuum pump 8 is connected to the other end of the rubber tube 4 through a valve 7. . Then, while closing the valve 5 on the side of the container 6, with the other valves 3 and 7 open, the vacuum pump 8 is started to evacuate the non-condensable gas such as 9 air from the inside of the container 1.
Then, the valve 7 on the vacuum pump 8 side is closed, and the valve 5 on the container 6 side is opened to inject the working fluid into the container 1. In that case, after sending a small amount of working fluid into the container 1, the valve 5 on the container 6 side is closed and the vacuum pump 8 is closed.
With the side valve 7 open, the container 1 may be heated to evaporate the working fluid, thereby discharging the non-condensable gas together with the working fluid vapor, so-called flushing, as appropriate.

After injecting the working fluid in this way, with all valves 3.5.7 closed, as shown in FIG.
The nozzle 2 is crushed at its distal end, that is, from the base end on the container 1 side, leaving a protrusion of a predetermined length, and is temporarily sealed.

Next, the lower end of the container 1 is immersed in a suitable heating medium 9 as shown in FIG. 3, and the working fluid 10 in the container 1 is evaporated and vaporized. For example, when water is used as the working fluid, heating at 200° C. for 1 to 2 hours is sufficient. As a result, gases such as O2 and CO2 dissolved in the working fluid 10 or decomposed gases from substances adhering to the inner surface of the container 1 are generated, but these non-condensable gases 11 are swept upward by the working fluid vapor 12. and is pushed into the inside of the nozzle 2.

Then, with the non-condensable gas 11 entering the inside of the nozzle 2 as described above, the nozzle 2 is opened as shown in FIG.
The proximal end of the tube is crushed to perform the final sealing.

That is, in the method of the present invention, the non-condensable gas 11 generated when the heat pipe is operated for the first time is sealed inside the nozzle 2 and removed from the inside of the container 1.

When carrying out the method of the present invention, the amount of non-condensable fluid generated is almost determined by the type and amount of working fluid, so the length and thickness of the nozzle should be determined depending on the type and amount of working fluid used. good.

Effects of the Invention As is clear from the above explanation, according to the method of the present invention, non-condensable scum generated when heating is input for the first time after injecting the working fluid is removed from the inside of the nozzle used for injecting the working fluid. Since it can be sealed and removed from the inside of the container, it is possible to obtain a heat pipe with excellent heat transport properties in which evaporation of the working fluid is not inhibited.

[Brief explanation of drawings]

1 to 4 are schematic diagrams showing the process of manufacturing a heat pipe according to the method of the present invention, in which FIG. 1 shows the working fluid injection process, FIG. 2 shows the nozzle temporary sealing process, and FIG. The figure shows the heating process, and FIG. 4 shows the nozzle unsealing process. DESCRIPTION OF SYMBOLS 1... Container, 2... Nozzle, 10... Working fluid, 11... Non-condensable gas, 12... Working fluid vapor.

Claims (1)

[Claims] A container enclosing a working fluid is provided with a nozzle for injecting/sealing the working fluid from a thin tube, and the working fluid is injected through the nozzle into the inside of the container from which non-condensable gas has been evacuated. , the nozzle is temporarily sealed leaving a protrusion of a predetermined length from the container, and then the non-condensable gas in the container is transferred to the inside of the nozzle by heating the container and evaporating the working fluid inside. A method for manufacturing a heat pipe, characterized in that the non-condensable gas is removed from inside the container by causing the nozzle to enter the container and then finally sealing the nozzle at the base end on the container side.