JPS5918632B2 - Heat pipe hydraulic fluid filling method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for filling a heat pipe with a working fluid, which quickly and reliably fills the pipe with a working fluid.

In general, a heat pipe is a pipe such as a metal pipe or a glass pipe whose interior is degassed and a working fluid is sealed therein, and the working fluid rapidly repeats evaporation and condensation to achieve high-speed heat propagation.

In this way, heat pipes use condensable steam, and if there is residual non-condensable gas such as air that does not contribute to heat propagation, the heat transfer ability will decrease. It is necessary to remove toxic gases.

Conventional methods for manufacturing heat pipes can be roughly divided into two methods as described below.

First, the first method is to first fill a pipe with a narrow opening at one end and a narrow opening for sealing off at the other end, then fill the pipe with a working fluid, and then evacuate the inside of the pipe using a vacuum pump through the narrow opening. This is a method of manufacturing a heat pipe by sealing the inside by sealing off the narrow opening when a predetermined pressure is reached with the liquid remaining.

The second method is to manufacture a heat pipe by first reducing the pressure inside the pipe using a vacuum pump, then injecting a predetermined amount of working fluid, and then sealing the inside by sealing off the narrow opening.

However, in the former method, the hydraulic fluid evaporates during the degassing process, so it is difficult to adjust the amount of hydraulic fluid sealed, and the hydraulic fluid is injected into the pipe through the sealing hole, which is particularly difficult for pipes with small diameters. The workability is extremely poor.

In addition, the latter method has disadvantages in that since the working fluid is poured into the pipe after degassing the pipe, especially low boiling point working fluid evaporates immediately after being injected into the pipe, increasing the internal pressure and making subsequent injection difficult.

In view of the above, the present invention has been developed as a result of various researches, and it is possible to obtain a heat pipe having a desired heat propagation ability by performing deaeration inside the pipe, filling the pipe with working fluid, and adjusting the amount of working fluid in a series of steps. The present invention provides a method for filling a heat pipe with a working fluid and an apparatus therefor.

That is, in the present invention, after exhausting the non-condensable gas in a pressure-resistant container containing a working fluid, a pipe that becomes a heat pipe with a deaerated interior is connected to a pipe attachment port provided in the container, and then the inside of the container is evacuated. The first gist of the present invention is a method for filling a heat pipe with working fluid, which is characterized by injecting a desired amount of working fluid into the pipe while pressurizing the heat pipe.

Furthermore, the present invention provides an exhaust port for discharging non-condensable gas in the upper part of the pressure-resistant container containing the working fluid, and has one end branched at the bottom of the container as an exhaust port connected to a vacuum pump, and the other end is connected to a pipe. The second gist is a working fluid filling device for a heat pipe, which is provided with a branch pipe as a mouth, and is equipped with a mechanism for pressurizing the inside of the container, and a liquid level meter for measuring the amount of working fluid. be.

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

FIG. 1 shows an outline of the device of the present invention. This hydraulic fluid filling device is equipped with a pressure-resistant cylindrical container 2 containing a hydraulic fluid 1, and an exhaust port 3 for discharging non-condensable gas at the top of the container 2. A branch pipe 4 is provided at the bottom, and a band heater 5 is wound around the outer surface of the container 2 in close contact with it to serve as a pressurizing mechanism, and a glass tube is formed on the side of the container 2 to communicate with this. A liquid level gauge 6 is provided.

Further, the branch pipe 4 has its upper end communicated with the bottom of the container 2, and has one branched end as an exhaust port 8 connected to a vacuum pump 7, and the other end as a metal or ceramic pipe 9 that becomes a heat pipe. is used as a pipe attachment port 10 to be detachably attached.

In the figure, 11 is an exhaust port 3 for discharging non-condensable gas.
12 is a pressure gauge attached to the top of the container 2, 13 is a lid provided to the top of the container 2, 14 is a narrow opening formed at one end of the pipe 9, 15a, 15tz15ct1
5d and 15e indicate husband valves.

A method for filling the pipe 9 with the hydraulic fluid 1 in the apparatus configured as described above will now be described.

First, the lid 13 of the container 2 is removed, and the working fluid 1 is poured into the container 2 from here.

The working fluid 1 has a relatively low boiling point, such as Freon R-12, Freon R''-22, and ammonia.

Next, the valves 15a and 15b are opened and the vacuum pump 11 is used to degas the non-condensable gas such as air remaining in the container 2, and also remove the non-condensable gas dissolved in the working fluid 1. Degas.

This degassing state is monitored using the pressure gauge 12, and when a predetermined value is reached, the valves 15a and 15b are closed.

Thereafter, the band heater 5 is energized to heat and evaporate the working fluid 1, thereby increasing the pressure inside the container 2.

Separately, the narrow opening 14 of the pipe 9 with one end closed, which will become a heat pipe, is attached to the pipe attachment port 10 formed at one end of the branch pipe 4, and the vacuum pump 7 is attached to the exhaust port 8, and the valve 15e is opened. to evacuate the inside of the pipe 9.

After the inside of the pipe 9 is brought to a predetermined pressure in this way, the valve 15e is closed, and then the valve 15d is opened, and the hydraulic fluid 1 in the container 2 is forced into the pipe 9 through the branch pipe 4.

In this case, since the working fluid 1 that has flowed into the deaerated pipe 9 has a low boiling point, it evaporates immediately and the pressure inside the pipe 9 increases, but as mentioned above, the inside of the container 2 is heated by the band heater 5 and the pressure increases. Therefore, the pressure inside the pipe 9 is overcome and the hydraulic fluid 1 is pressurized.

The filling amount of the hydraulic fluid 1 is adjusted by checking the amount of drop in the hydraulic fluid level using a flow meter 6, and when a predetermined amount is pressurized, a valve 15
Close d.

Next, in this state, the narrow opening 14 is caulked and sealed to produce a heat pipe.

In the above device, the container 2 is made of an opaque material such as metal, and the liquid meter 6 is made of a transparent glass tube communicating with the container 2. However, it is also possible to make part or all of the container 2 transparent. However, a scale may be provided here so that the level of the working fluid in the container 2 can be directly viewed.

Further, although the pressure mechanism is shown in which the band heater 5 is provided in close contact with the outer periphery of the container 2, the present invention is not limited to this.
It is also possible to use one that is heated directly.

Alternatively, as shown in FIG. 2, a bellows-shaped hollow body 16 that can expand and contract freely is housed in the container 2, and a high-pressure fluid is pressurized into the hollow body 16 from the outside to pressurize the inside. .

Further, the hollow body 16 is not limited to a bellows-shaped one, but may be a balloon-shaped one, and the hollow body 16 is not provided inside the container 2, but is provided outside in communication with the container 2, so that the non-condensable gas in the container 2 can be After evacuating, the hollow body 16 may be compressed to increase the internal pressure of the container 2.

Next, specific examples of the present invention will be described.

A glass liquid meter 6 is installed on the side of a metal cylindrical container 2 with a diameter of 330 mm and a height of 450 mm, and the outer circumferential surface is 1 kW.
A device as shown in FIG. 1 was assembled by installing band heaters 5 in close contact with each other.

In addition, the inner diameter of the pipe 9 serving as a heat pipe is 10 mm.
A copper pipe with a diameter of 1500 imO was used and was attached to the branch pipe 4 provided at the bottom of the container 2.

In this device, Freon R-1 is first used as the working fluid 1.
2 was placed in the container 2 and degassed for about 30 minutes using the vacuum pump 11 to exhaust the non-condensable gas, and then heated with the band heater 5. After about 10 minutes, the pressure inside the container 2 was about 2 kg.
/cr? It became t.

Separately, the inside of the pipe 9 is degassed in advance using the vacuum pump 7, and the container 2 is kept in a pressurized state, and the valve 15 is
When d was opened, the hydraulic fluid 1 was smoothly pressurized into the pipe 9.

After injecting a predetermined amount of hydraulic fluid 1 in this way, the narrow opening 1
4 was caulked to make a sealed cut-off shihito pipe.

This heat pipe did not contain non-condensable gases such as air that do not contribute to heat propagation, and the specified performance was achieved.

As explained above, according to the present invention, since the inside of the container containing the working fluid is deaerated, non-condensable gas that does not contribute to heat propagation is not mixed into the heat pipe, and the inside of the container is pressurized. Since the working fluid is pressurized into the pipe, it is possible to overcome the pressure increase when filling with a low boiling point working fluid and fill it smoothly, making it extremely easy to work, especially when manufacturing heat pipes with small pipe diameters. It has remarkable effects such as excellent performance.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram schematically showing a working fluid filling device for a heat pipe according to the present invention, and FIG. 2 is a sectional view of the device in which a bellows-shaped hollow body is provided as a pressurizing mechanism. 1... Working fluid, 2... Container, 3... Exhaust port, 4...
... Branch pipe, 5... Band heater, 6... Liquid meter, 7... Vacuum pump, 8... Exhaust port, 9... Pipe, 10... Pipe installation port, 11... ··Vacuum pump,
12...Pressure gauge, 16...Hollow body.

Claims (1)

[Scope of Claims] 1. After exhausting the non-condensable gas in a pressure-resistant container containing a working fluid, a pipe that will become a heat pipe with the interior deaerated is connected to a pipe attachment port provided in the container, and then A method for filling a heat pipe with working fluid, which comprises pressurizing the inside of the container while pressurizing a desired amount of working fluid into the pipe. 2 An exhaust port for discharging non-condensable gas is provided at the top of the pressure-resistant container containing the working fluid, and one end branched at the bottom of the container is used as an exhaust port to connect to a vacuum pump, and the other end is used as a pipe installation port. A heat pipe working fluid filling device comprising a branch pipe, a mechanism for pressurizing the inside of the container, and a liquid level meter for measuring the amount of working fluid. 3. A working fluid filling device for a heat pipe according to claim 2, wherein a heater is provided inside or on the outside of the pressure-resistant container as a mechanism for pressurizing the inside of the container. 4. A working fluid filling device for a heat pipe according to claim 2, wherein a hollow body that is expanded by pressurized fluid is provided inside the pressure-resistant container as a mechanism for processing the inside of the container.