JP3016093B2 - Heat absorbing wall for space environment test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention forms a high-vacuum and cryogenic environment which is almost equivalent to the space environment, and is used for testing various devices used in space such as artificial satellites. The present invention relates to a space environment test apparatus, and more particularly to a structure of a heat absorbing wall used in a space environment test apparatus.

[Conventional technology]

In general, a space environment test apparatus (space chamber) simulates the darkness and darkness of the universe by installing a heat absorbing wall called a shroud or a shield inside a vacuum vessel, and evacuating the inside of the vacuum vessel with a vacuum pump. It simulates the high vacuum of the universe. That is, shroud 100K
It is common to simulate the darkness and darkness of the universe by cooling below, and as the cold source, liquid nitrogen and helium have been mainly used. Further, in order to accommodate a specimen with a large amount of released gas in the vacuum container and exhaust it to a high vacuum,
It is necessary to evacuate using a large pump for evacuation, but in such a case, a cryogenic exhaust surface, that is, a cryopanel is incorporated in the inside of the vacuum vessel or shroud, and the cryopanel is cooled to 20K or less. It is necessary to function as a cryopump for condensing and exhausting gas such as nitrogen.
Helium supplied from a helium refrigerator is conventionally used as a cooling source for the cryopanel.

In addition, when the inside of the vacuum vessel is heated to room temperature after the test is completed, it is generally performed by introducing nitrogen gas or helium gas into the shroud.

Conventionally, as the space environment test device, a vertical type in which the axis of the vacuum vessel is a vertical direction has been mainly used.
In recent years, so-called horizontal space environment test devices have been manufactured in which the diameter of the vacuum vessel is made 8 m or more and the axis of the vacuum vessel is set to be horizontal so that a large artificial satellite can be tested. .

On the other hand, among the shrouds installed in the vacuum container, the body shroud installed on the container body usually has a fin tube or the like having a liquid nitrogen flow path, and the flow path is parallel to the container axis. That is, liquid nitrogen is caused to flow from one end plate of the vacuum container to the other end plate. Therefore, in the conventional vertical space environment test apparatus, the flow of liquid nitrogen can be easily changed to an upward flow from bottom to top, so that gas accumulation does not occur.
It was possible to cool the inside of the vacuum container uniformly.

[Problems to be solved by the invention]

However, in the horizontal space environment test apparatus, for example, as shown in FIG. 5, the shroud used for the conventional vertical type is made horizontal, and the inlet manifold 1 is provided on one side and the outlet manifold is provided on the other side. 2 is disposed, and a large number of fin tubes 3 having a horizontal flow path are disposed between both manifolds 1 and 2, the liquid nitrogen used as the cooling fluid for the shroud is a fluid having a low boiling point and easy to gasify. Therefore, when the liquid nitrogen evaporates and gasifies inside the fin tube 3, a gas pool is generated in the portion and the flow of the liquid nitrogen is obstructed, and the flow rate of the liquid nitrogen in each fin tube becomes unbalanced, and the shroud Could not be cooled to a uniform temperature.

Therefore, as shown in FIG. 6, the liquid nitrogen flow path 4 of the plurality of fin tubes is continuously formed so that even when the liquid nitrogen is vaporized and gasified, the gas is pushed out by the liquid nitrogen flow. It is possible. This structure has no problem when the vacuum vessel is small, but has a problem that when the vacuum vessel becomes large, the length of the flow path becomes long, so that the pressure loss increases.

As shown in FIG. 7, when several flow paths 5 are connected together to one fluid nitrogen supply source 6 in order to shorten the flow path length, the pressure loss due to the liquid head is adjusted. Therefore, a valve is required for each connection part, and a large number of valves have to be provided.

Therefore, the present invention is particularly applicable to a large and horizontal space environment test apparatus, in which liquid nitrogen can be efficiently circulated, there is no problem of gas accumulation or pressure loss, and pipes can be efficiently installed. It is intended to provide a heat absorbing wall.

[Means for solving the problem]

In order to achieve the above-described object, the present invention provides a vacuum container having a horizontal axis, which is disposed inside a vacuum container, and which is cooled by a cold fluid flowing through a cold fluid flow path from an introduction portion toward an outlet portion. In a heat absorbing wall for a space environment test device cooled to a low temperature, the heat absorbing wall is divided into two or more blocks,
In each block, the cold fluid flow paths are arranged side by side, and the introduction section communicates with the inlet manifold, and the outlet section communicates with the outlet manifold, respectively. It is characterized in that the manifold is arranged so as to be at the upper end.

〔Example〕

Hereinafter, the present invention will be described in more detail based on one embodiment shown in the drawings.

FIG. 1 is a perspective view showing an arrangement state of a shroud in a vacuum vessel, FIG. 2 is a front view showing an arrangement state of a body shroud, FIG. 3 is a sectional view of a main part of the shroud, and FIG. FIG.

First, as shown in FIG. 1 and FIG. 2, a horizontal space environment test apparatus 11 shown in this embodiment includes a head plate shroud block 13 disposed at both ends in a vacuum vessel 12 having an axis extending in a horizontal direction. , 13 and a plurality of body shroud blocks 14, 14 arranged on the body of the container. Each of the shroud blocks 13, 14 is formed by extrusion of an aluminum alloy as shown in FIGS. 3 and 4, respectively.
On both sides of a tube body 15a serving as a cold fluid flow path, fin tubes 15 integrally formed with wing sides 15b, 15b having jagged irregularities on the fin surface are arranged innumerably without gaps, and a trunk shroud block 14 is provided. In the above, the fin tubes 15 are formed in an arc shape having a curvature along the curved surface of the body of the vacuum vessel 12, and a large number of the fin tubes 15 are arranged along the wall of the vacuum vessel 12 concentrically with the inner peripheral wall without any gap. Things. Note that the shape of the fin tube 15 is not limited to the above shape, and for example, the fin surface may be a flat surface instead of a jagged uneven surface.

A large number of fin tubes 15 arranged side by side on each shroud block 13, 14 are provided with inlet manifolds 16 for introducing liquid nitrogen, each having an introduction portion at one end provided for each block.
The outlets at the other ends are connected to the outlet manifold 17, respectively. The shroud blocks 13 and 14 are disposed so that the inlet manifold is located at the lower end and the outlet manifold is located at the upper end with respect to each cold fluid flow path, and liquid that is distributed from a liquid nitrogen supply pipe (not shown) to the inlet manifold 16 is provided. Nitrogen is introduced from the lower end of each fin tube 15 as an ascending flow, drawn out from the upper end to the outlet manifold 17, and further circulated from the outlet manifold 17 back to the liquid nitrogen return pipe.

Usually, the manifolds 16, 17 and the fin tube 15 are connected via a vent tube and a coupling, respectively.

As described above, the shroud provided in the vacuum vessel 12 is divided into two or more shroud blocks in which a plurality of fin tubes 15 are combined, and the introduction portion of the fin tubes 15 is provided at the inlet manifold, and the lead-out portion is provided. The inlet manifold is connected to the outlet manifold, and the inlet manifold is
By arranging the outlet manifold 17 at the lowermost end and the outlet manifold 17 at the uppermost end, liquid nitrogen can be used as an upward flow, and the nitrogen gas gasified in the fin tube 15 is lifted upward by its own buoyancy. It moves smoothly and does not hinder the flow of liquid nitrogen. Also, the length of the fin tube 15 can be set within an appropriate pressure loss range, and the valve for supplying liquid nitrogen is also
For example, only the portion corresponding to the inlet manifold 16 is required.

Furthermore, in the body part shroud block 14, the liquid nitrogen head in each fin tube 15 uses a self-balancing function to make the pressure loss constant and the flow rate in each shroud block uniform by the head of liquid nitrogen in each fin tube 15. And each shroud block can be cooled to a uniform temperature.

The number of shroud divisions and the number of fin tubes provided in each shroud block can be determined in consideration of the size and manufacturability of the vacuum vessel. Usually, the circumference of the body is divided into two or four. It is preferable to divide the blocks into blocks of the same size as much as possible.

[Effects of the Invention] As described above, the heat absorbing wall for the space environment test apparatus of the present invention divides the heat absorbing wall (shroud) into two or more blocks, and the blocks are arranged in parallel with each other. The cold fluid introduction section at one end of the fluid flow path is formed to communicate with the inlet manifold, and the cold fluid outlet section is formed so as to communicate with the exit manifold. For each cold fluid flow path, the inlet manifold is at the lowermost end, and the outlet manifold is at the uppermost end. Liquid nitrogen can be used as an ascending flow, and gas that has been gasified in the cold fluid flow path smoothly moves upward due to its own buoyancy,
The flow of the cold fluid is not hindered, and the differential pressure of each flow path becomes constant by the head pressure of the liquid nitrogen, so that each flow rate becomes uniform and the entire heat absorbing wall can be uniformly cooled.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view showing an arrangement state of a shroud, FIG. 2 is a front view showing an arrangement state of a body shroud, and FIG. Is a sectional view of a main part of the shroud, FIG.
FIG. 5 to FIG. 7 are schematic views showing the state of the cold fluid flow path in the conventional shroud. 11 ... Space environment test equipment, 12 ... Vacuum container, 13 ... Shroud block of head plate, 14 ... Shroud block of body, 15 ... Fin tube, 16 ... Inlet manifold, 17 ...
Exit manifold

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 19/00 B64G 7/00

Claims (1)

(57) [Claims] 1. A space environment test apparatus which is disposed inside a vacuum vessel having an axis extending in a horizontal direction, and cools the inside of the vacuum vessel to a very low temperature by a cold fluid flowing through a cold fluid flow path from an introduction portion to a discharge portion. In the heat absorbing wall for use, the heat absorbing wall is divided into two or more blocks, and each block is provided with the cold fluid flow path in parallel, the introduction part is an inlet manifold, and the outlet part is an outlet manifold. A heat absorbing wall for a space environment test apparatus, wherein the heat absorbing walls are arranged so as to communicate with each other, with an inlet manifold at a lower end and an outlet manifold at an upper end with respect to each cold fluid flow path.