JPS6138396A - Loop type heat pipe - Google Patents

Abstract

PURPOSE:To improve the operating characteristics of heat pipe by a method wherein a cooler, serving both for cooling section and a pressure regulating tank, is employed in a loop circuit while the loop circuit is provided with a non- return valve. CONSTITUTION:A free space, in which heat medium 12 does not exist, is formed in the upper part of the cooler 5 and the cooler 5 is provided with pressure regulating function. The heat medium 12 absorbs heat in a heating section 13, the flow direction thereof is restricted by the non-return valve 14, it ascends through an ascending tube 1 and is introduced into the cooler 5 through an upper connecting tube 3 whereby the heat medium 12 is cooled and releases heat absorbed by it in the heating section 13. The heat medium 12, which released the absorbed heat in the cooler 5, descends through a descending pipe 2 and the flow of whole of the heat medium 12, sealed in the loop, becomes a circulating flow shown by an arrow sign in the diagram. Consequently, smooth flow may be obtained and fluctuations of pressure and temperature may be improved remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a loop-type heat pipe using a loop circuit.

[Prior art and problems] Conventionally, as a heat transfer device that moves a heat medium between a cold source and a hot source without using external mechanical driving force such as a power pump or compressor, Depipe and thermosyphon are known.

All of these transfer materials by utilizing the exchange of heat through evaporation and condensation of a liquid, which is a heat medium, and the phase change that occurs during this process, as well as the accompanying change in temperature.

In these heat pipes and thermosiphons, the steam rising passage and the condensate return passage are each provided within the same pipe. For example, in the case of a heat pipe, a hollow portion within the pipe forms a vapor passage, and a tube wall portion forms a condensate return path. In addition, in this heat pipe, the inner wall of the pipe is lined with a porous material in order to promote the reflux of condensed liquid, making the internal structure complex and significantly increasing manufacturing costs. .

[Purpose] In view of the above-mentioned circumstances, the present inventors first sealed a heat medium in a loop circuit that separately includes an ascending pipe and a downcomer pipe, heated it in the lower limb of the ascending pipe, and heated it in the upper part of the downcomer pipe. proposed a loop-type heat transfer element that performs cooling using
No. 0191).

Soshi - Inspection of operating characteristics of C-loop heat pipe B4
As a result, we discovered that the operating characteristics can be improved by using a cooler that also serves as a cooling section and a pressure regulating tank, and by providing a check valve in the loop circuit, and have completed the present invention.

"Configuration 1 According to the present invention, a loop circuit separately includes a rising pipe and a downcomer pipe, a heat medium which is a working fluid sealed in the loop circuit under vacuum, and forming a part of the loop circuit, and a communication port to the riser pipe is located above the loop i path, and a communication port to the riser pipe is provided on the side surface of the container, and a communication port to the descender pipe is provided on the bottom surface of the container, and a cooling fluid pipe is provided inside the container. A loop consisting of a cooler that also serves as a pressure regulating tank, a heating section located at the lower part of the riser pipe, and a check valve interposed at the lower part of the loop circuit to limit the flow direction of the working fluid in the loop circuit. type heat pipe is provided.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings. 1 is an ascending pipe, 2 is a descending pipe, which are provided at an appropriate distance from each other, and whose upper and lower parts are connected to the upper part. They are connected by a connecting pipe 3 and a lower connecting pipe 4. 5 is a cooler that also serves as a pressure adjustment tank, and its structure consists of an upper connecting pipe 3 on the side of the container.
6, a lower communication port with the downcomer pipe 2 on the bottom of the container, and a communication port 1 that can communicate with the outside system via an on-off valve 8.9 on the top of the container.
0, and a cooling fluid conduit 11 is provided inside the container. An ascending pipe 1, a descending pipe 2, an upper connecting pipe 3, a lower connecting pipe 4, and a cooler 5 form a loop circuit. 12 is a heating medium which is a working fluid sealed in the loop circuit under vacuum; 13 is a heating section located at the lower part of the riser pipe 1;
Reference numeral 4 designates a check valve which is interposed in the lower part of the loop circuit, that is, in the lower connecting pipe 4, and is configured to circulate the working fluid in the loop circuit only in the direction of the arrow.

In the case of the present invention, the heat medium 12 is a liquid metal such as sodium, potassium, or mercury, which is commonly used in the past.
An organic heat medium such as Dow△ or Freon, water, etc. can be used, and the amount of heat medium sealed in the loop circuit is not particularly limited, and can range from 5 to 100% of the internal volume of the loop circuit. Even at 100%, the free surface of the heat medium 12 is formed at the height of the communication port 6 in the cooler 5. Therefore, regardless of the amount of heat medium enclosed, there is no presence of the heat medium 12 in the upper part of the cooler 5. A free space is formed, which provides the cooler 5 with a pressure regulating function. The heat medium 12 is sealed by connecting it to the vacuum pump system through the communication port 10 and the on-off valve 9 at the top of the cooler 5, and after making the entire loop circuit system evacuated, the on-off valve 8 and the communication port 10 are connected to the vacuum pump system. Intercede.

Note that after the heat medium 12 is sealed, the communication port 10 may be completely closed by welding or the like, if necessary.

Since the loop heat pipe according to the present invention is configured as described above, the heat medium 12, which is the working fluid, absorbs heat in the heating section 13, and its flow direction is restricted by the check valve 14, causing it to rise. It ascends the pipe 1, passes through the upper connecting pipe 3, is guided to the cooler 5, and is cooled, where the heat absorbed by the heating section 13 is released. Heat carrier 1 that has released absorbed heat in cooler 5
2 descends through the downcomer pipe 2, and the entire flow of the enclosed heat medium 12 becomes a circulating flow in the direction of the arrow. In addition, since a smoother flow is obtained compared to the case without a check valve, pressure fluctuations and temperature/reaction fluctuations are significantly improved. The flow pattern of the heat medium 12 in the riser pipe 1-upper connecting pipe 3 system depends on the type of heat medium 12,
Depending on the enclosed amount, the amount of heat absorbed from the heating section 13, etc., the flow may be a liquid single-phase flow, a gas-liquid two-phase flow such as an air swirling flow, a slag flow, or an annular spray flow, which varies depending on the operating conditions. The flow pattern □ in the downcomer pipe 2-lower connecting pipe 4 system is the flow pattern in the riser pipe 1-upper connecting pipe 3 system plus the influence of the amount of heat released □ in the cooler 5. Pressure loss characteristics preferred as a heat transfer device,
Designed to obtain heat transfer characteristics and used under optimal conditions,
Needless to say, you should drive.

[Effect] The check valve 14 installed in the lower connecting pipe 4 contributes to improving heat transfer characteristics. The loop circuit system is connected to the pressure sensor via the on-off valve 8, and also at the bottom of the rising pipe 1, near the outlet of the heating section 13, near the joint between the upper connecting pipe 3 and the cooler 5, and between the descending pipe 2 and the cooler 5. near the joint with the lower connecting pipe 4 and the heating section 1
A wetness filter was placed near the joint with No. 3, water was used as the heat medium, and pressure fluctuations, hot water temperature fluctuations, and temperature distribution were compared with and without the check valve 14. As a result, it was confirmed that when the check valve 14 was installed, the fluctuations in pressure and temperature were much smaller, and the temperature distribution was improved toward uniformity. Furthermore, it has been found that the cooler 5 also has a pressure regulating function as described above due to its structure, and is effective in suppressing pressure fluctuations.

The heat pipe in the present invention does not necessarily have to be as shown in the drawings, and various modifications may be made.
I can do that. For example, the ascending pipe 1 and the descending pipe 2 do not necessarily have to be vertical pipes, but can also be formed into an annular loop. In any case, in the heat pipe of the present invention, the rising pipe 1 for raising the heat medium 12 and the down pipe 2 for lowering the heat medium 12 are separate, and the cooler 5 which also serves as a pressure regulator always has free space. Any device can be used as long as it forms a loop circuit together with the check valve 14 that limits the flow direction of the heat medium 12.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of the loop type heat pipe of the present invention.

Claims (1)

[Claims] (1) A loop circuit that separately includes a riser pipe and a downcomer pipe, a heat medium that is a working fluid sealed in the loop circuit under vacuum, and a heat medium that forms a part of the loop circuit and is placed above the loop circuit. The container has a communication port to the rising pipe on the side surface of the container, a communication port to the descending pipe on the bottom surface of the container, and a cooling fluid pipe line inside the container, which also serves as a pressure regulating tank. A loop heat pipe comprising a cooler, a heating section located at the lower part of the riser pipe, and a check valve interposed at the lower part of the loop circuit to limit the flow direction of the working fluid in the loop circuit.