JP2008221875A - Ventilation duct for spacecraft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ventilation duct capable of shutting out the heat inputted from the outside on an orbit and functioning as a heat radiation face while ensuring an air vent flow passage when reducing pressure of a spacecraft and launching it. <P>SOLUTION: This ventilation duct for the spacecraft is provided with a structural body panel 4 provided with a through-hole 5 passing through the inside and the outside of the spacecraft, a lid 1 attached to the outside of the structural body panel 4 to cover the through hole 5 while forming a clearance between the structural body panel 4 and it, and a radiation shielding plate provided in the clearance between the structural body panel 4 and the lid 1 to surround the through hole 5 and form the air ventilation flow passage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spacecraft ventilation duct that secures an air escape passage during decompression when launching a spacecraft such as an artificial satellite or a spacecraft.

  As a conventional technique, there is known a ventilation duct in which a hollow bracket is provided on the outside of a structure panel so as to surround a through hole of a space mechanism panel. In this ventilation duct, a light shielding BOX composed of a shell and a heat insulating sheet is attached around a through hole inside the structure panel (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-59770 (FIG. 5)

  In recent years, the amount of heat generated by onboard equipment has increased with the advancement of spacecraft functionality. In order to maintain the exhaust heat performance, securing the area of the heat radiation surface on the spacecraft panel is an important issue. Although the conventional exhaust duct has a shielding effect against heat input from the outside, it does not have exhaust heat performance as a heat radiating surface. For this reason, by installing a ventilation duct on the heat radiating surface of the structure panel, there is a problem that the heat radiating area is reduced and the heat exhausting ability is lowered.

  An object of the present invention is to obtain a ventilation duct that can shut off heat input from the outside on an orbit and can also function as a heat radiating surface while ensuring an air escape passage when a spacecraft is launched and decompressed. Yes.

  The spacecraft ventilation duct according to the present invention includes a structure panel provided with a through-hole penetrating the inside and outside of the spacecraft, and the structure panel having a gap between the structure panel and covering the through-hole. And a radiation shielding plate that is provided in a gap between the lid and the structure panel and surrounds the periphery of the through hole, and the radiation shielding plate has an opening between the outside of the spacecraft and the through hole. Ventilation holes that communicate with each other are provided.

  According to the present invention, for a spacecraft that secures an air escape passage at the time of spacecraft launch depressurization, blocks heat input from the outside in orbit, and reduces a reduction in heat radiation area due to formation of a through hole. A ventilation duct can be obtained.

Embodiment 1 FIG.
1A and 1B are views showing the structure of a ventilation duct according to Embodiment 1 of the present invention. FIG. 1A is a front view, and FIG. 1B is a side view. 2 is a cross-sectional view taken along the line AA in FIG. The ventilation duct is formed by a lid 1, a radiation shielding plate 2 on the lid side, a radiation shielding plate 3 on the structure panel side, a structure panel 4 of a spacecraft, and a through hole 5 opened on the structure panel 4. Consists of air passages. The structure panel 4 forms a structure of a spacecraft, and FIG. 1 illustrates a heat radiation surface portion of the structure panel. The through hole 5 is formed in the heat radiating surface portion of the structure panel 4 and penetrates the structure panel 4 to ventilate the inside and outside. The radiation shielding plate 2 on the lid side and the radiation shielding plate 3 on the structure panel side constitute a radiation shielding plate.

  The lid 1 is disposed at a predetermined distance from the heat radiation surface portion of the structure panel 4. The lid 1 has a disc shape, and a radiation shielding plate 2 on the lid side is attached to the surface (inner surface side) of the lid 1 facing the structure panel 4. In the example of FIG. 1, the lid 1 and the radiation shielding plate 2 on the lid side form a cylindrical shape with an opening on the structure panel 4 side. Around the through hole 5, a radiation shielding plate 3 on the structure panel side is attached in a ring shape. In the example of FIG. 1, the radiation shielding plate 3 on the structure panel side has a cylindrical shape with an opening on the lid 1 side. The radiation shielding plate 3 on the structure panel side includes a stay mechanism (extension member) for attaching the lid 1. As a result, the lid 1 is attached in a state of floating from the structure panel 4, and a ventilation path from the through hole 5 to the lid 1 is formed. Further, the outer diameter of the radiation shielding plate 2 on the lid side is larger than the outer diameter of the radiation shielding plate 3 on the structure panel side. As a result, a vent for exhausting air discharged from the space mechanism body is formed between the radiation shielding plate 2 on the lid side and the radiation shielding plate 3 on the structure panel side.

  The air duct configured in this way reduces the pressure difference when the pressure outside the satellite decreases with respect to the pressure inside the satellite when the satellite is launched, and when a pressure difference occurs between the inside and outside of the satellite. Thus, it functions as an air vent channel for exhausting the air inside the satellite to the outside of the satellite. FIG. 2 shows an air passage as the air escape passage. As shown in the figure, when the satellite is launched, the air inside the satellite is exhausted outside the satellite along the arrow in the figure.

  Since there are no moving parts in this air flow path, a reliable and highly reliable air flow path and thermal control performance can be expected.

Here, the heat shielding effect will be described as the heat control function.
In the figure, the external dimensions are the mounting height of the lid 1 (distance from the outer surface of the structure panel 4 to the outer surface of the lid 1) h, the mounting height of the radiation shielding plate 2 on the lid side (radiation shielding plate on the lid side) 2) a, and the mounting height of the radiation shielding plate 3 on the structure panel side (width of the radiation shielding plate 3 on the structure panel side) b. In the first embodiment, the dimensions are set so that the lid mounting height h ≦ the mounting height a of the radiation shielding plate 2 on the lid side + the mounting height b of the radiation shielding plate 3 on the structure panel side. For this reason, when the minimum elevation angle of the external heat input on the orbit with respect to the structure panel 4 is 0 °, the external heat input can be reliably shielded from entering the structure. In addition, since the inner surface of the lid 1 is subjected to a surface treatment that absorbs infrared rays, the reflected heat is absorbed by the inner surface of the lid 1 even if external heat input is reflected by the outer surface of the structure panel 4. Therefore, it is not reflected by the through hole 5.

  Next, heat dissipation characteristics will be described. The surface optical characteristics of the outer side and the inner side of the lid 1, the radiation shielding plate 2 on the lid side, and the radiation shielding plate 3 on the structure panel side are the same as or equivalent to the surface optical characteristics of the outer side and the inner side of the structure panel 4. By performing the surface treatment, the lid 1, the radiation shielding plate 2 on the lid side, and the radiation shielding plate 3 on the structure panel side function as a heat radiation surface of the spacecraft.

  FIG. 3 is a partial cross-sectional view of the surface of the lid 1. In the figure, the lid 1 is made of an aluminum alloy 16. A silver vapor-deposited tape 11 is attached to the outer surface of the lid 1. The silver vapor-deposited tape 11 includes a fluororesin-based synthetic resin Teflon (registered trademark) 13 having silver 14 deposited on the inside and an adhesive 15 attached to the inside of the silver 14. A black paint 17 is applied to the inside of the lid 1. In addition, also about the surface of each radiation shielding board, since the external surface and the internal surface have comprised the same structure, description is abbreviate | omitted here.

  Here, the silver vapor-deposited tape 11 is obtained by vapor-depositing silver 14 having a low solar absorptance α on Teflon (registered trademark) 13 having a high infrared emissivity ε and a characteristic of transmitting sunlight. In general, α ≦ 0.01 and ε ≧ 0.75 depending on the thickness of Teflon (registered trademark), aging, and the like. Sunlight passes through Teflon (registered trademark) 13, but is reflected by silver 14 and again passes through Teflon (registered trademark) 13 to return to outer space. For this reason, the heat is not absorbed. On the other hand, the heat generated inside the structure is radiatively coupled to the black painted surface on the inner surface of the lid 1 and absorbed. The heat absorbed by the inner surface of the lid 1 is transmitted to the Teflon (registered trademark) 13 on the outer surface by the heat conduction of the aluminum alloy 16 which is the base material of the lid 1. From there, due to the characteristics of Teflon (registered trademark) 13, it is radiated as thermal energy in the infrared region into outer space. That is, the heat radiated through the through hole 5 is radiatively coupled to the inner surface of the lid 1, conducts heat inside the lid 1, and is radiated from the outer surface of the lid 1 to the outer space.

  In addition to the silver vapor-deposited tape 11, the heat-dissipating surface may be white paint (having a low α and high ε as a material property, but the α value deteriorates and becomes high by solar irradiation), OSR (Otical soler reflector; Teflon ( Instead of (registered trademark), quartz may be used). Further, as the material of the lid 1, an aluminum honeycomb panel, a CFRP honeycomb panel, or the like may be used. In particular, in the case of CFRP, black coating is not necessary.

Embodiment 2. FIG.
FIG. 4 is a diagram showing the configuration of the second embodiment according to the present invention, and a multilayer heat insulating sheet 6 is attached to the outer surface of the structure panel 4 of the spacecraft. A multilayer heat insulating sheet 6 is attached to the outer surface of the lid 1, the radiation shielding plate 2 on the lid side, and the radiation shielding plate 3 on the structure panel side. Other configurations are the same as those in the first embodiment.

  In this embodiment, the same heat insulation as that of the structure panel 4 to which the multilayer heat insulation sheet is attached is provided by attaching the multilayer heat insulation sheet 7 to the outside of the cover 1, the radiation shield plate 2 on the cover side, and the radiation shield plate 3 on the structure panel side. Can have functions.

Embodiment 3 FIG.
FIG. 5 is a diagram showing a third embodiment of the present invention, in which the lid-side radiation shielding plate 2 is not provided in the first or second embodiment. Instead of the cover-side radiation shielding plate 2 according to the first or second embodiment, the structure-side radiation shielding plate 3 is covered with a lid so that a gap is formed between the cover 1 and the structure-side radiation shielding plate 3. A mounting stay 8 is provided.

  In this embodiment, when the minimum elevation angle of the external heat input on the orbit with respect to the structure panel 4 of the spacecraft is 0 ° or more, it is possible to shield the external heat input from entering the structure. Further, since the inner surface of the lid 1 and the radiation shielding plate 3 on the structure side is subjected to a surface treatment that absorbs infrared rays, the lid 1 and the structure even if external heat input is reflected on the outer surface of the structure panel 4. The reflected heat is absorbed by the inner side surface of the radiation shielding plate 3 on the side, so that it is not reflected by the through hole 5.

Embodiment 4 FIG.
FIG. 6 is a view showing Embodiment 4 of the present invention, and a lid mounting stay 8 is provided around the through hole 5 in the structure panel 4 of the spacecraft. There is no structure-side radiation shielding plate 5 according to the first or second embodiment. Instead, the lid is attached so that a gap is formed between the cover 1 and the radiation shielding plate 2 on the lid side and the structure panel 4. A stay 8 is installed.

  In this embodiment, when the minimum elevation angle of the external heat input on the orbit for the spacecraft panel 4 or 6 is 0 ° or more, the external heat input can be shielded from entering the structure. In addition, since the inner surface of the lid 1 is subjected to a surface treatment that absorbs infrared rays, even if external heat input is reflected on the outer surface of the structure panel 4, most of the reflected heat is reflected on the inner surface of the lid 1. Since it is absorbed, the heat reflected by the through-hole 5 can be reduced.

Embodiment 5. FIG.
FIG. 7 is a diagram showing a fifth embodiment of the present invention, in which the lid side radiation shielding plate 2 is not provided in the fourth embodiment.

  In this embodiment, when the minimum elevation angle of the external heat input on the orbit for the spacecraft panel 4 or 6 is 0 ° or more, the external heat input can be shielded from entering the structure. In addition, since the inner surface of the lid 1 is subjected to a surface treatment that absorbs infrared rays, even if external heat input is reflected on the outer surface of the structure panel 4, most of the reflected heat is reflected on the inner surface of the lid 1. Since it is absorbed, the heat reflected by the through-hole 5 can be reduced.

It is a figure which shows Embodiment 1 of the ventilation duct which concerns on this invention. FIG. 3 is a view showing a cross section of a ventilation duct according to the first embodiment. 4 is a partial cross-sectional view of the surface of the lid according to Embodiment 1. FIG. It is a figure which shows Embodiment 2 of the ventilation duct which concerns on this invention. It is a figure which shows Embodiment 3 of the ventilation duct which concerns on this invention. It is a figure which shows Embodiment 4 of the ventilation duct which concerns on this invention. It is a figure which shows Embodiment 5 of the ventilation duct which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Cover, 2 Radiation shielding board on the lid side, 3 Radiation shielding board on the structure panel side, 4 Structure panel (heat radiation part), 5 Through-hole, 6 Multi-layer insulation sheet, 8 Stay for lid attachment.

Claims (5)

A structure panel provided with a through hole penetrating the inside and outside of the spacecraft;
A lid attached to the outside of the structure panel so as to cover the through hole with a gap between the structure panel and
A radiation shielding plate provided in a gap between the lid and the structure panel and surrounding the periphery of the through hole;
With
An air duct for a spacecraft, wherein the radiation shielding plate is provided with a vent opening communicating between the outside of the spacecraft and a through hole. The radiation shielding plate is composed of a lid-side radiation shielding plate attached to the surface of the lid on the structure panel side, and a structure-side radiation shielding plate attached to the structure panel in an annular shape,
The lid-side radiation shielding plate and the structure-side radiation shielding plate have different outer diameters, and a vent is formed by a gap between the lid-side radiation shielding plate and the structure-side radiation shielding plate. The ventilation duct for spacecraft according to claim 1. The sum of the width of the radiation shielding plate on the lid side and the width of the radiation shielding plate on the structure side is configured to be larger than the distance between the outer surface of the lid and the outer surface of the structure panel. The ventilation duct for spacecraft according to claim 2. The lid, the radiation shielding plate on the lid side, and the inner and outer surfaces of the radiation shielding plate on the structure side are subjected to a surface treatment that is the same or equivalent to the inner or outer surface optical characteristics of the structure panel. The ventilation duct for spacecraft according to claim 2. The space duct according to claim 2, wherein a multilayer heat insulating sheet is attached to an outer surface of the lid, the radiation shielding plate on the lid side, and the radiation shielding plate on the structure side.

Images