JP2005059770A - Ventilation duct - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain thermal input on a regular orbit; to air-cool an apparatus on a highly heated part inside a satellite at a fairring air conditioning just before launching; and to secure an air vent passage at the time of launching decompression of the artificial satellite. <P>SOLUTION: In a structure panel used for the artificial satellite, when a sun incident light maximum elevation angle on the orbit is β°, the ventilation duct having a through hole is provided on the structure panel having a hollow bracket of which height is tan ( β°) times or more of an inside diameter on an upper part, and thereby air-cooling in the highly heated part inside the satellite can be effectively performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to device air cooling in a satellite fairing before launching an artificial satellite and securing an air escape channel during launch depressurization.

  The conventional technology for cooling inside the satellite fairing before launching the artificial satellite enables simultaneous launch of artificial satellites with different air conditioning conditions by dividing the fairing into a plurality of regions and performing air conditioning under different air conditioning conditions ( For example, see Patent Document 1.)

JP-A-6-8891

  The conventional technology can cope with a plurality of artificial satellites having different air conditioning conditions in the satellite fairing, but it cannot cope with efficient thermal control of only a certain part in one artificial satellite. For example, while propulsion system equipment and propellants arranged in the entire satellite need to be maintained near normal temperature, the battery has an allowable upper limit temperature of 25 ° C. Desirably, since the temperature rises locally due to self-heating due to charge / discharge before launch, it is necessary to increase the efficiency of only the battery unit and control the heat. The thermal control on the steady orbit of the battery unit is designed to cover the surrounding area with a multilayer insulation sheet to minimize the orbital heat input and to radiate heat from the heat radiation surface provided on the outer surface of the mounting panel. The heat dissipation efficiency of the heat radiating surface by the heat pipe is increased with respect to the increase in heat generation density and heat generation density. Immediately before launch, there are heat pipes that do not operate under ground gravity due to layout restrictions, there is a temperature difference between the front and back of the mounting panel, and the ambient air conditioning temperature cannot be lowered unnecessarily due to restrictions of other installed equipment, There is a need to increase the thermal control efficiency of the high heat-generating equipment before launch.

  The present invention has been made to solve the above-described problems, and suppresses heat input in a steady orbit while simultaneously air-cooling a high-heat-generating device portion inside the satellite at the time of fairing air conditioning immediately before launch. The purpose is to obtain a ventilation duct.

  The ventilation duct according to the present invention covers a structure panel that blocks the inside and outside of an artificial satellite, a through hole having an inner diameter d provided so as to penetrate the structure panel, and covers the through hole on the outside of the structure panel. A hollow bracket provided to conceal, and when the maximum elevation angle of solar incident light on a steady orbit with respect to the structure panel is β °, the hollow bracket has a height h that is tan (β °) times the inner diameter. That's it.

  According to the ventilation duct of the present invention, the heat input on the steady orbit can be suppressed, and at the same time, it is possible to inexpensively cool the portion of the high heat generating device inside the satellite during the fairing air conditioning immediately before launch.

Embodiment 1 FIG.
FIG. 1 is a diagram showing Embodiment 1 of the present invention, in which 1 is a hollow bracket, 2 is a satellite structure panel, and 3 is a through hole formed on the structure panel 2. FIG.
The ventilation duct of the present invention is composed of a through hole 3 opened on the satellite structure panel 2 and a hollow bracket 1 attached to the through hole 3. As shown in the figure, the outer dimensions are a height h, an inner diameter d, and the like. To do.

When the maximum elevation angle of the solar incident light on the stationary orbit with respect to the structure panel 2 is β °, the maximum elevation angle β of the solar incident light with respect to the north-south panel surface is 23 for a satellite such as a communication satellite that takes a three-axis attitude on the geostationary orbit. .5 °.
In the case of the hollow bracket 1 to be mounted on the north-south panel surface in the case of an elevation angle where the solar incident light is maximum, if the height h is not less than tan (23.5 °) times the inner diameter d, the solar incident Light can be shielded by the hollow bracket 1.

  In the ventilation duct configured as described above, the height h of the hollow bracket 1 disposed at the upper portion is not less than tan (β °) times the inner diameter d. It is blocked by the inner wall and does not enter the through hole 3.

  Therefore, since the orbital heat input incident through the through hole 3 can be reduced, it is possible to eliminate the temperature rise due to the direct sunlight on the steady orbit, and to suppress the deterioration of the thermal control performance due to this.

  Also, during fairing air conditioning just before launch, it becomes possible to guide the air conditioned air to a part of the satellite that generates high heat, such as a battery, and indirectly cools through heat conduction of the heat radiating panel. Compared to the above, it is possible to efficiently cool by direct air cooling.

  Furthermore, the ventilation duct configured in this way reduces the atmospheric pressure difference between the inside and outside of the satellite because the atmospheric pressure outside the satellite decreases relative to the atmospheric pressure inside the satellite when the satellite is launched. Although the action to make is necessary, it also functions as an air escape passage as an action at the time of this pressure reduction.

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

In addition, when the test is performed on the ground, the ventilation duct configured as described above can be used as a hole through which the test cable passes, and the test preparation time can be shortened.
The range of flight configurations that must be changed for testing is reduced and workmanship reliability is improved.

Embodiment 2. FIG.
FIG. 2 is a diagram showing a second embodiment of the present invention, 4 is a black painted surface of the inner wall of the hollow bracket, and 1-3 are the same as those of the first embodiment.

  The black painted surface 4 of the inner wall of the hollow bracket 1 is painted black so that the solar absorptance is 0.9 or more.

  Solar direct light on the orbit is blocked by the black painted surface 4 of the hollow bracket 1 and the hollow bracket inner wall of the hollow bracket 1, and 90% or more of the sunlight incident on the black painted surface 4 of the hollow bracket inner wall is on the hollow bracket inner wall. It is absorbed by the black painted surface 4.

  Since the solar multiple reflected light incident on the ventilation duct configured as described above can be reduced, it is possible to further improve the thermal control performance on the steady orbit as compared with the first embodiment.

Embodiment 3 FIG.
FIG. 3 is a diagram showing a third embodiment of the present invention, 5 is a silverated polyetherimide on the outer surface of the hollow bracket, and 1-3 are the same as in the first embodiment.

  The silverized polyetherimide 5 on the outer surface of the hollow bracket 1 is a heat control material for the outer surface of the hollow bracket 1, and “α (sunlight absorption rate) / ε (infrared emissivity)” is 0.24 / 0.78 or less. It is.

  The temperature of the hollow bracket 1 is controlled to be low because the α / ε of the silylated polyetherimide 5 on the outer surface of the hollow bracket 1 is small. For this reason, the heat generated by conduction and infrared radiation incident on the through hole 3 from the inner wall of the hollow bracket 1. Can be reduced.

  In the ventilation duct configured as described above, conduction and infrared heat input are reduced, so that it is possible to further improve the thermal control performance on a steady orbit as compared to the first embodiment. In contrast to the fact that light reflected from the inner wall surface of the hollow bracket 1 and directly entering the inside through the through hole 3 can be eliminated, in Embodiment 3, the absorption of heat by the outer wall surface of the hollow bracket 1 is reduced and the temperature is reduced. Since it can reduce, the heat | fever by the conduction | electrical_connection and infrared radiation which enter the through-hole 3 from the hollow bracket 1 can be made small.

Embodiment 4 FIG.
FIG. 4 is a view showing Embodiment 4 of the present invention, 6 is a heat insulating spacer, and 1 to 3 are the same as those in Embodiment 1 described above.

  The heat insulating spacer 6 is made of GFRP which is a low thermal conductivity material, and even when the hollow bracket 1 is hotter than the structure panel 2, the amount of heat incident on the structure panel by conduction is suppressed.

  Therefore, in the ventilation duct configured as described above, it is possible to further improve the thermal control performance on the steady track as compared with the first embodiment.

Embodiment 5 FIG.
FIG. 5 is a diagram showing Embodiment 5 of the present invention, 7 is a multilayer heat insulating sheet, 8 is a shell that maintains the shape of the multilayer heat insulating sheet 7, 1-3 are the same as in Embodiment 1, and 6 is the embodiment. This is the same as Form 4.

On the side opposite to the hollow bracket 1 of the satellite structure panel 2, it is installed so as to cover the through hole 3 on the satellite structure panel 2, and the shell 8 constitutes a light shielding BOX.
In addition, the shell 8 insulates the surface with a multilayer heat insulating sheet 7.

  Therefore, the multiple reflected light and infrared light from the inner wall of the hollow bracket 1 are further reduced by the multilayer heat insulating sheet 7.

  In the ventilation duct configured as described above, the amount of heat passing through the through hole 3 from the outside of the satellite can be suppressed as compared with the first embodiment, and the heat control performance on the steady orbit can be further improved.

It is a figure which shows Embodiment 1 of the ventilation duct in connection with this invention. It is a figure which shows Embodiment 2 of the ventilation duct in connection with this invention. It is a figure which shows Embodiment 3 of the ventilation duct in connection with this invention. It is a figure which shows Embodiment 4 of the ventilation duct in connection with this invention. It is a figure which shows Embodiment 5 of the ventilation duct in connection with this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hollow bracket 2 Satellite structure panel 3 Through-hole 4 Black painted surface of hollow bracket inner wall 5 Silverized polyetherimide of hollow bracket outer surface 6 Thermal insulation spacer 7 Multilayer thermal insulation sheet 8 Shell

Claims (5)

A structure panel that blocks the inside and outside of the satellite,
A through hole having an inner diameter d provided so as to penetrate the structure panel;
A hollow bracket provided to cover the through hole on the outside of the structure panel;
Comprising
A ventilation duct characterized in that the height of the hollow bracket is not less than tan (β °) times the inner diameter d when the maximum elevation angle of solar incident light on a steady orbit with respect to the structure panel is β °. The ventilation duct according to claim 1, wherein the inner surface of the hollow bracket is manufactured by performing black coating, black plating, or the like. By providing the outer surface of the hollow bracket with silver fluorinated resin, white paint, etc.
The ventilation duct according to claim 2, wherein the heat is controlled so that "α (sunlight absorption rate) / ε (infrared emissivity)"<0.3 of the surface thermo-optical characteristics. The ventilation duct according to any one of claims 1 to 3, wherein a heat insulating spacer made of a low thermal conductivity material such as GFRP is sandwiched between the hollow bracket and the structure panel. The light shielding BOX comprised with the multilayer heat insulation sheet, the heat insulating material, etc. was provided in the internal side wall surface of the said structure panel so that the said through-hole might be covered, The any one of Claims 1-4 characterized by the above-mentioned. The ventilation duct as described in the item.

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