JPH08200976A - Evaporating tube - Google Patents

Abstract

PURPOSE: To realize the operation control with high reliability by making a liquid film uniform. CONSTITUTION: A liquid passage 12 in which operating liquid is supplied is provided in parallel with a vapor passage 11 in which a capillary tube structure 13 is inserted in a tube axial direction, the passage 11 communicates with the passage 12 via a communicating groove 112. The structure 13 in which a hydrophilic material layer 131 and a hydrophobic material layer 13 are sequentially laminated from the wall surface side is inserted into the passage 11, the operating liquid supplied to the passage 12 by the capillarity of the structure 13 is spread to the wall of the passage 11 to always form a desired liquid film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-phase fluid loop suitable for an exhaust heat system of a spacecraft including artificial satellites, a capillary pump loop, and an evaporation pipe used as an evaporation unit for a large capacity heat pipe. Regarding

[0002]

2. Description of the Related Art In this type of evaporation pipe, a liquid passage and a vapor passage are arranged in parallel, and the working liquid supplied to the liquid passage is guided to the vapor passage through a communication groove, and a liquid film is formed on the wall surface of the vapor passage. By forming the above, the working fluid deprives the heat quantity of the heating element (not shown) and evaporates, and the working fluid vapor is exhausted through the steam passage. The wall surface of this vapor path is provided with a capillary structure in which hydrophilic material is inserted in grooves called a plurality of grooves in the tube axis direction, and the working fluid introduced from the liquid path by the capillary force of this capillary structure is applied to the wall surface. It is configured to be distributed and form a liquid film. At this time, the working liquid guided to the wall surface of the evaporation path has a concave liquid surface due to the action of the capillary force of the capillary structure, and the liquid pressure is set lower than the vapor pressure by the surface tension.

By the way, in such an evaporation tube,
When used as an evaporator of a two-phase fluid loop type exhaust heat system, for example, in order to compensate the pressure loss of the loop, a transfer pump is used to forcibly supply the working liquid from the condenser to the liquid passage.

However, in the above-mentioned evaporation pipe, when the transfer pump is configured to forcibly transfer the working liquid, the hydraulic pressure of the working liquid is increased due to fluctuations in the pump head of the transfer pump, miscontrol of the pump head, and the like. It may fluctuate and become higher than the vapor pressure. According to this, there is a problem that the liquid film formed on the wall surface of the vapor path grows too thick and becomes too thick, normal evaporation cannot be performed, and an unstable phenomenon such as boiling occurs. Such a problem is particularly serious in the field of space development where highly reliable motion control is required.

[0005]

As described above, in the conventional evaporation pipe, when the working liquid is forcibly transferred, the liquid pressure is changed to obtain a desired liquid film. However, there is a problem that an unstable phenomenon such as boiling of the working fluid occurs.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an evaporation tube which has a simple structure and is capable of uniformizing a liquid film, and which realizes highly reliable operation control. To aim.

[0007]

According to the present invention, a liquid passage to which a working liquid is supplied is provided in parallel with a vapor passage having a capillary structure inserted in a pipe axial direction, and an operation to be supplied to the liquid passage is performed. In an evaporation tube formed by forming a liquid film on the wall surface of the evaporation path by guiding the liquid to the steam path through the communication groove and by the capillary force of the capillary structure, the capillary structure is provided with a hydrophilic material from the wall surface side of the steam path. A layer and a hydrophobic material layer are provided in this order.

[0008]

According to the above structure, in the capillary structure, the hydrophilic material layer holds the working fluid in a predetermined liquid pressure of the liquid passage, and the interface between the working fluid and the vapor is formed into a concave shape, Set the liquid pressure lower than the vapor pressure. Then, when the hydraulic pressure of the hydraulic fluid in the liquid passage increases, the liquid level of the hydraulic fluid rises and reaches the hydrophobic material layer,
The interface with the wall surface is changed to a convex shape, and a pressure against the hydraulic pressure is generated. Therefore, a constant liquid film is always ensured regardless of the hydraulic pressure, and highly reliable operation control is possible.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an evaporation pipe according to an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a pipe line main body, in which a vapor line 11 and a liquid line 12 are arranged in parallel in the axial direction of the pipe. Of these, the steam passage 11 is connected to a condenser (not shown), and a plurality of grooves 111 called grooves are formed in the tube axial direction on the inner wall surface of the steam passage 11 at predetermined intervals in the circumferential direction. A substantially hollow capillary structure 13 is inserted inside the groove 111. In this capillary structure 13, as shown in FIG. 2, the hydrophilic material layer 131 formed of a fiber material or the like has the groove 1 described above.
The hydrophilic material layer 131 is stacked on the inner wall surface of the vapor passage 11 including the hydrophobic material layer 131, and the hydrophobic material layer 132 is provided on the hydrophilic material layer 131. The hydrophobic material layer 132 is formed of, for example, a mesh material.

A plurality of communication grooves 112, which are substantially orthogonal to the plurality of grooves 111 on the inner wall, are formed on the outer wall surface of the steam passage 11 at predetermined intervals in the tube axial direction. The plurality of communication grooves 112 communicate with the plurality of grooves 111 and the liquid passage 12, respectively.

On the other hand, the liquid path 12 is the above-mentioned condensing part (not shown).
Connected to the working fluid outlet of the working fluid, the working fluid from the vapor condenser (not shown) is transferred in the direction of the arrow through a transfer pump (not shown).

In the above structure, when the working fluid from the condensing section (not shown) is supplied from one end of the liquid passage 12 via the transfer pump (not shown), the working fluid is first fed. It is guided to the groove 111 of the steam path 11 through the communication groove 112. Then, the hydraulic fluid spreads to the wall surface of the vapor passage 11 by the capillary force of the capillary structure 13, and forms a liquid film on the wall surface. At this time, the hydraulic fluid is held by the hydrophilic material layer 131 of the capillary structure 13, the interface with the wall surface is set to a concave shape, and the hydraulic pressure is set to be lower than the vapor pressure. Here, the liquid film takes away the amount of heat of a heating element (not shown) installed in the conduit main body 10 and evaporates, and the evaporated working liquid vapor is guided to the condensing section (not shown) through the vapor passage 11. And condensed, and the working fluid outlet of the condensing part (not shown) is again guided to the liquid path by the transfer pump (not shown).

When the pump head of a transfer pump (not shown) changes and the hydraulic pressure increases in the above evaporation operation state, the hydraulic fluid has a liquid level higher than that of the hydrophilic material layer 131 of the capillary structure 13. Ascending, hydrophobic material layer 132
And the interface with the evaporation passage 11 is changed into a convex shape by the action of the hydrophobic material layer 132. As a result, the hydraulic fluid generates a pressure against the pump head of the transfer pump (not shown), and the liquid film formed on the wall surface of the vapor passage 11 is maintained in the initial state.

As described above, in the evaporation pipe, the liquid passage 12 to which the working liquid is supplied is juxtaposed to the vapor passage 11 in which the capillary structure 13 is inserted in the pipe axial direction, and these vapor passages 11 and While communicating between the liquid passages 12 through the communication groove 112,
A capillary structure 13 in which a hydrophilic material layer 131 and a hydrophobic material layer 132 are stacked in order from the wall surface side is inserted into the vapor passage 11 and the hydraulic fluid supplied to the liquid passage 12 by the capillary force of the capillary structure 13 is inserted. It was constructed so as to spread over the wall surface of the evaporation passage 11 to form a desired liquid film. According to this, the hydrophilic material layer 131 of the capillary structure 13 holds the hydraulic fluid in a predetermined state of the hydraulic pressure of the hydraulic passage 12, and the interface of the hydraulic fluid is set to a concave shape, thereby When the pressure rises, the liquid level of the hydraulic fluid rises to reach the hydrophobic material layer 132 of the capillary structure 13, and its interface changes into a convex shape, thereby generating a pressure against the fluid pressure, and It is operated to keep a liquid film. Therefore, even when it is applied to an exhaust heat system in which a transfer pump (not shown) or the like is used to forcibly transfer the hydraulic fluid to the liquid passage 12, it is affected by changes in the hydraulic pressure. In addition, since the liquid film formed on the wall surface of the evaporation passage 11 can be made uniform, highly reliable operation control that surely realizes highly efficient heat absorption characteristics becomes possible.

In the above embodiment, the hydrophilic material layer 131 of the capillary structure 13 is made of a fiber material and the hydrophobic material layer 132 is made of a mesh material. However, the invention is not limited to this. It is also possible to use a binding metal or the like. Therefore, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

[0016]

As described in detail above, according to the present invention, it is possible to provide an evaporation tube which has a simple structure and is capable of uniformizing a liquid film, and which realizes highly reliable operation control. You can

[Brief description of drawings]

FIG. 1 is a diagram showing an evaporation pipe according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of FIG. 1 in detail.

[Explanation of symbols]

10 ... Pipe line main body, 11 ... Steam path, 12 ... Liquid path, 111 ...
Groove, 112 ... Communication groove, 13 ... Capillary structure, 131 ... Hydrophilic material layer, 132 ... Hydrophobic material layer.

Claims (2)

[Claims] 1. A liquid passage to which a working liquid is supplied is arranged in parallel with a vapor passage having a capillary structure inserted in a pipe axial direction, and the working liquid supplied to the liquid passage is passed through a communication groove to form the vapor passage. In the evaporation tube formed by forming a liquid film on the wall surface of the evaporation path by the capillary force of the capillary structure, the capillary structure has a hydrophilic material layer and a hydrophobic material layer in order from the wall surface side of the vapor path. An evaporation tube characterized by being provided. 2. The evaporation tube according to claim 1, wherein in the capillary structure, the hydrophilic material layer is formed of a fiber material and the hydrophobic material layer is formed of a mesh material.