JPS6287787A - Pouring of low boiling point operating fluid - Google Patents

Abstract

PURPOSE:To permit to pour the specified amount of low boiling point fluid quickly into a sealed pipe for a heat pipe from a high-pressure vessel as operating fluid by a method wherein the sealed pipe is evacuated and, thereafter, a temperature difference is set to that the temperature of the high-pressure vessel becomes higher than the temperature of the sealed pipe. CONSTITUTION:A vacuum pump 4 is started under a condition that a valve 7 at the side of a cylinder 6 is closed and the other valves 2, 5 are opened to discharge non-condensible gas such as air or the like from a sealed pipe 1 and evacuate the sealed pipe 1. Subsequently, the valve 5 at the side of the vacuum pump 4 is closed and the valve 7 at the side of the cylinder 6 is opened. As a result, low boiling point fluid flows from the bomb 6 into the sealed pipe 1 by the difference of internal pressures between the bomb 6 and the sealed pipe 1. The temperature of the bomb 6 is kept in constant by a heating device 8, therefore, a vapor pressure in the cylinder is higher at all times than the inside of the sealed pip 1 and, accordingly, fluid in the cylinder 6 flows into the sealed pipe 1 continuously where by the operating fluid may be poured into the sealed pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is essential for manufacturing heat pipes in which a low boiling point fluid such as Freon R-12 or R-22 (both trade names) is used as a working fluid in a sealed pipe. This relates to a method of injecting into the body.

As is well known in the art, a heat pipe operates by completely exhausting a non-condensable gas such as air from the inside of a closed tube, and then operating a condensable fluid such as a low boiling point fluid or water or ammonia. It has a structure in which a porous structure such as a metal mesh that generates capillary pressure is inserted into the sealed tube as a wick, and the liquid-phase working fluid is evaporated by heat input from the outside. After the vapor flows to the lower pressure end side, it radiates heat and condenses to liquefy, transferring heat as latent heat to the working fluid, and the liquid phase working fluid is returned to the evaporation section by the capillary pressure generated in the wick. It is something that makes you In order to continue and smoothly transport heat in such a heat pipe, it is necessary to almost completely exhaust the non-condensable gas inside the sealed pipe and inject a necessary and sufficient amount of working fluid to turn it off. There is.

Conventionally, such evacuation of non-condensable gas and injection of a working fluid made of a low boiling point fluid have been carried out as follows.

In other words, a vacuum pump and a cylinder filled with a pressurized liquefied low-boiling point fluid are connected to a sealed tube that has been cleaned and removed from oil and other substances that generate gas in a vacuum state via a switching valve mechanism. First, a vacuum pump is driven to suction and exhaust non-condensable gas such as air from inside the sealed tube, and then a small amount of fluid is pumped into the sealed tube from the cylinder to perform so-called flushing. Furthermore, non-condensable gases are completely excluded, and then a low boiling point fluid is fed from the cylinder into the sealed tube.

Problems to be Solved by the Invention However, when the above-mentioned low boiling point fluid is used as the working fluid, the fluid inside the cylinder expands adiabatically during flushing and subsequent injection, causing its temperature to drop and its vapor pressure to decrease. In contrast, the internal pressure of the sealed tube for the heat pipe gradually increases from the vacuum state as the working fluid is injected.

Therefore, if a certain amount of low boiling point fluid is continuously injected, the vapor pressure on the cylinder side and the closed tube side will be balanced, and the fluid will not be injected into the closed tube beyond a certain level, and the specified amount of working fluid will not be injected. It becomes impossible to inject L into a sealed tube,
This problem becomes particularly noticeable when a low boiling point fluid is injected into a large number of sealed tubes.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a method that can quickly inject a low boiling point fluid at a specified port as a working fluid into a sealed tube for a heat pipe.

Means for Solving the Problems In order to achieve the above objects, the present invention manufactures a heat pipe by injecting a pressurized liquefied low-boiling fluid from a high-pressure container into a sealed tube for a heat pipe as a working fluid. In order to do this, the non-condensable gas is suctioned and exhausted from inside the sealed tube to create a vacuum inside the sealed tube, and then the high pressure is set with a temperature difference set so that the temperature of the high pressure container is higher than the temperature of the sealed tube. This method is characterized by injecting the low boiling point fluid from a container into a sealed tube.

Function: Also in the method of the present invention, at the beginning of the injection of working fluid, the inside of the sealed tube is in a vacuum state, and the vapor pressure of the fluid on the wide high-pressure container side is sufficiently high, so that the fluid flows smoothly into the sealed tube. However, even if fluid is continuously injected from the high-pressure container into the sealed tube, the temperature is set so that the temperature inside the high-pressure container is higher than the temperature in the sealed tube, so the vapor pressure of the fluid will decrease. The pressure is always higher on the high-pressure vessel side, and as a result, the working fluid always flows from the high-pressure vessel toward the sealed pipe.

EXAMPLES Hereinafter, the method of the present invention will be specifically explained based on examples.

FIG. 1 is a schematic diagram showing an example of an apparatus for implementing the method of the present invention, in which a T-shaped flexible high-pressure rubber tube 3 is connected to one end of a sealed tube 1 for a heat pipe via a valve 2. , at one end of the rubber tube 3,
A vacuum pump 4 is connected via a valve 5, and the other end of the rubber tube 3 is filled with Freon R to be used as a working fluid.
A cylinder 6 containing a pressurized liquefied low boiling point fluid such as -12 or R-22 (all trade names) is connected via a valve 7. A heating device 8 is attached to the cylinder 7 to maintain the temperature above a certain level. Further, the sealed tube 1 is placed on a weighing device 9 so that the amount of fluid to be injected can be determined.

In order to inject fluid into the sealed tube 1 once with the above device, first close the valve 7 on the cylinder 6 side, start the vacuum pump 4 with the other valves 2 and 5 open, and then Non-condensable gas such as air is evacuated from 1, and the inside thereof is brought into a vacuum state. Then, the valve 5 on the vacuum pump 4 side is closed, and the valve 7 on the cylinder 6 side is opened. As a result, the low boiling point fluid flows from the cylinder 6 into the sealed tube 1 due to the difference in internal pressure between the cylinder 6 and the sealed tube 1 . In that case, either adiabatic expansion of the low boiling point fluid occurs inside the cylinder 6, or the cylinder 6 is maintained at a constant temperature by the heating device 8, so the vapor pressure inside the cylinder 6 is always higher than that inside the sealed tube 1. Therefore, the fluid in the cylinder 6 continues to flow toward the sealed tube 1, and the working fluid can be injected. In this case, a temperature difference of about 10 to 20'C between the cylinder 6 and the sealed tube 1 is sufficient.

As a result of injecting in this manner, when the display on the scale 9 shows the specified amount, each valve 2, 4.7 is closed to stop the infusion.

In addition, the method of this invention sets a temperature difference between a high-pressure container containing a low-boiling point fluid and a closed tube for a heat pipe, and maintains a high vapor pressure on the high-pressure container side at all times. Therefore, instead of heating the cylinder as shown in the above embodiment, the closed tube may be cooled to set the temperature difference as described above.

Effects of the Invention As is clear from the above explanation, according to the method of the present invention, the vapor pressure balance between the high-pressure container side and the closed pipe side due to the injection of low-boiling point fluid and its adiabatic expansion is resolved, and the high-pressure container side Since the vapor pressure of the heat pipe can be maintained high at all times, the low boiling point fluid as the working fluid can be rapidly and continuously injected into the closed tube for the heat pipe.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of an apparatus for carrying out the method of the present invention. 1... Sealed tube, 4... Vacuum pump, 6... Cylinder, 8... Heating device.

Claims (1)

[Claims] When manufacturing a heat pipe by injecting a pressurized liquefied low-boiling fluid from a high-pressure container into a sealed tube for a heat pipe as a working fluid, a non-condensable gas is sucked out from inside the sealed tube to create a vacuum state inside the sealed tube. and then injecting the low boiling point fluid from the high pressure container into the closed tube with a temperature difference set so that the temperature of the high pressure container is higher than the temperature of the closed tube. Injection method.