JPH0615360B2 - Radiation cooler - Google Patents

Description

Description: (a) Technical Field of the Invention The present invention relates to an improvement for preventing performance deterioration of a radiation cooler that cools an infrared detector mounted on a satellite by heat radiation to outer space. Is.

(b) Conventional background Photon-type detectors made of multi-element semiconductors such as HgCdTe are used as infrared detectors for infrared cameras installed in recent resource exploration satellites. Although these are highly sensitive and have a fast response speed, they do not operate unless they are at an extremely low temperature of about 100 ° K, and their performance is also hindered by, for example, outgas, which obstructs the transmittance of infrared rays. For this reason, such infrared detectors mounted on satellites are cooled to the operating temperature by utilizing a radiation cooler.The radiation surface of the radiation cooler, the mirror surface of the reflector, and the optical detector of the infrared detector are used. Outgas that hinders heat dissipation efficiency easily adheres to the system,
There is a strong demand for development of a radiation cooler having a function capable of accurately removing this.

(c) Conventional Technology and Problems FIG. 1 is a diagram for explaining the relationship between the structure of a conventional radiation cooler and the earth. In FIG. 1, 1 is a satellite body,
2 is a side surface of the artificial satellite body, 2'is an infrared passage hole, 3 is the earth, 4 is infrared, 5 is a mirror, 6 is an infrared detector, 7 is a first cooling plate, 7'is a heat radiating surface of the first cooling plate. , 8 is a reflector,
8'is a reflecting mirror surface, 9 is a second cooling plate, 9'is a radiating surface of a second cooling plate, 10 is a sealing plate, 11 is a heat insulating material, 12 is outgas, 40 is a radiating cooler, and 50 is outer space. ing.

As shown in FIG. 1, a conventional radiation cooler 40 is mounted on a side surface 2 of an artificial satellite body 1 and emits infrared rays 4 emitted from a target earth 3 via a mirror 5 attached to the satellite body 1. Infrared detector 6 that receives light in a direction orthogonal to the vertical line of
Is the main subject. The detector 6 is supported by a first cooling plate 7 whose mounting surface is directed toward the satellite side and the opposite surface is directed toward the outer space side as a heat dissipation surface 7 '.
A reflection plate 8 having a reflection mirror surface 8'that spreads in a funnel shape toward the outer space 50 is provided at the outer peripheral edge of the. Further, a second heat dissipating surface 9 ′ is formed so as to extend outward from the outer peripheral edge of the reflection plate 8 in parallel with the first cooling plate 7.
A cooling plate 9 and a shield plate 10, one of which extends from the outer peripheral end of the second cooling plate 9 to the space 50 side again in a funnel shape, and the other of which is fixed to the side plate 2 of the satellite body 1 are attached. There is. A heat insulating material 11 is filled in the cavity formed between the side plate 2 of the satellite body 1 and the radiation cooler 40. Then, the second cooling plate 9, the reflection plate 8, the first cooling plate 7, the infrared detector 6 and the like receive the heat rays from the sun and the earth and are not heated by the shield plate 10 so that the heat rays are not heated. Reflect to 50 (environmental temperature 4 ° K),
Alternatively, the temperature rise of the infrared detector 6 is prevented by heat radiation.

The heat from the satellite body 11, which is maintained at a standard temperature of 20 ° C. (293 ° K), is transmitted to the shield plate 10 through a heat insulating material (not shown), and the shield plate 10 reflects heat to the outer space 50. Even if the heat radiation is performed, the infrared detector 6 cannot be lowered to the ultra-low temperature (100 ° K) in the operating state.

The infrared detector 6 is operated at an extremely low temperature (100 ° K).
In order to lower the temperature, the above-mentioned object was solved by the following two-stage cooling.

That is, in the cooling in the first stage, the shield plate 10 is formed by using the stopper formed of a heat insulating material (not shown) for the reflection plate 8 and the second cooling plate 9 extending from the reflection plate 8. Is attached to.

The heat rays emitted obliquely from the earth by the reflection plate 8 are reflected to the outer space 50 so as not to be emitted to the first cooling plate 7.

However, the reflection plate 8 reflects most of the heat rays, but part of the heat rays is absorbed and becomes heat, which raises the temperature of the reflection plate 8.

Further, the heat of the shield plate 10 having a temperature higher than that of the reflection plate 8 is transmitted to the reflection plate 8 through the stopper formed of the heat insulating material (not shown), so that the temperature of the reflection plate 8 rises.

Therefore, the heat of the reflection plate 8 is transferred to the next first cooling plate 7 as follows.
In order to prevent the heat from being transmitted to the second cooling plate 9, the second cooling plate 9 radiates heat to the outer space 50 (environmental temperature of 4 ° K) to cool the reflection plate 8 and the second cooling plate 9.

However, since the second cooling plate 9 is also heated by the heat rays obliquely radiated from the earth, the reflecting plate 8 and the second cooling plate 9 can be cooled to a temperature close to an ultra low temperature (100 ° K). Ultra-low temperature (100
It cannot be specified as ° K).

Therefore, as the second stage cooling, the first cooling plate 7 having the infrared detector 6 attached thereto is attached to the reflection plate 8 using a stopper formed of a heat insulating material (not shown). By radiating heat to the outer space 50, the infrared detector 6 is cooled to an operating state at an ultralow temperature (100 ° K).

In this case, the heat transmitted from the reflection plate 8 through the stopper formed of the heat insulating material (not shown) has already reached a value close to the ultra-low temperature, and therefore has an effect on the temperature rise of the first cooling plate 7. Is few.

Also, the heat rays obliquely irradiated from the earth are the shield plate 1
0 and does not reach the first cooling plate 7 because it is reflected by the reflector plate 8 into the outer space 50, and thus is not heated.

In this way, the infrared detector 6 is kept in an operating state at an extremely low temperature (100 ° K).

However, in such a conventional structure, the standard temperature is 20 ° C.
Outgas from the satellite body 1, which maintains (269 ° K), flows in the direction of arrow B through the infrared passage hole 2'and adheres to the infrared detector 6 cooled to an ultralow temperature (100 ° K). Then, the outgas 12 from the heat insulating material 11 which has been frozen or otherwise placed in a vacuum state progresses in the directions of arrows C, D, E and F, and the heat radiating surface 7 of the detector 6 and the first cooler. ′ Or the mirror surface 8 ′ of the reflection plate, the heat radiation surface a ′ of the second cooling plate, etc., freezes and interferes with the infrared rays 4 entering the infrared detector 6, or the radiation efficiency as the radiation cooler 40. As a result, the reflection efficiency is deteriorated and the infrared detector 6 is insufficiently cooled, so that the detection function is significantly deteriorated.

It is generally known that the outgas 12 has a property of moving from a high temperature part to a low temperature part and from a high pressure part to a low pressure part. Further, since FIG. 1 is a side sectional view, only the upper and lower two surfaces of the radiation cooler 40 are shown, but in actuality, it has a structure in which the upper, lower, left and right four surfaces are surrounded.

(d) Object of the invention The present invention has been made to remedy the above-mentioned conventional drawbacks, and it is possible to remove outgas frozen and attached to an infrared detector and a radiation cooler in a timely manner to recover and maintain cooling performance. The purpose of the present invention is to provide a new radiation cooler capable of achieving the above.

(e) Structure of the Invention As shown in FIG. 2, the radiation cooler according to the present invention is mounted on the artificial hygiene body 1 and has an infrared detector 6 for detecting incident infrared rays 4 and the infrared detector 6 attached thereto. A first cooling plate 7 that cools the infrared detector 6 by heat radiation to the outer space 50 and heat-insulates the first cooling plate 7 from the outer peripheral edge of the first cooling plate 7 to the outer space 50 side. A reflecting plate 8 formed so as to spread in a funnel shape, a second cooling plate 9 extending further outward than an outer peripheral edge of the reflecting plate 8, and the second cooling plate 9
And an infrared detector 6, a first cooling plate 7, and a reflection plate, which are insulated from the first cooling plate 7 and expand outward from the outer peripheral edge of the second cooling plate 9 toward the outer space side. 8, a shield plate 10 for covering the second cooling plate 9, and heaters 13, 14 for radiating outgas 12 to at least one of the first cooling plate 7, the reflecting plate 8 and the second cooling plate 9,
15 is attached.

(f) Embodiments of the Invention Embodiments of the present invention will be described in detail below with reference to the drawings.

2 and 3 are views for explaining the structure and operation of the radiant cooler according to the present invention. FIG. 2 is a side sectional view of the radiant cooler, and FIG. 3 is a heater and a controller. A block diagram is shown.

In both figures, the same parts as those in the previous FIG. 1 are designated by the same reference numerals, 13 is a first cooling plate heating heater, 14 is a reflecting plate heating heater, 15 is a second cooling plate heating heater, and 20 is a heater power source. , 30 are control devices (ground stations), respectively.

As shown in FIG. 2, the radiative cooler according to the present invention is equipped with an outgas 1
Infrared detector 6 whose transmittance of infrared rays 4 has deteriorated due to adhesion freeze of 2 and heat radiation efficiency or reflection efficiency has decreased.
In order to recover the functions of the heat radiating surface 7'of the cooling plate 7, the mirror surface 8'of the reflecting plate 8 and the heat radiating surface 9'of the second cooling plate 9, the above-mentioned outgas 12 which has been adhered and frozen by heating these is put into space. It is characterized in that a heater is attached as a means for diffusing to the space 50 side. The heater is a first cooling plate heater 13 attached to the upper, lower, left and right sides of the inner cavity of the first cooling plate 7 (the left and right are not shown and the same applies to the following), and the mirror surface 8'of the reflector 8 is opposite. It comprises a reflector heating heater 14 provided on the upper, lower, left and right sides of the surface, and a second cooling plate heating heater 15 provided on the upper, lower, left and right sides of the second cooling plate 9 opposite to the heat radiating surface 9 '.

In operation, the decrease in the cooling function of the radiation cooler 40 due to the adhesion and freezing of the outgas 12 causes the temperature of the detector 6 to rise, and a temperature sensor (not shown) detects this and the controller (ground station) 30 shown in FIG. Contact. Then, in response to a command from the control device 30, the heater power source 20 attached to the satellite body 1 is activated to energize the first cooling plate heating heater 13, the reflecting plate heating heater 14 and the second cooling plate heating heater 15 and these heaters are turned on. Due to the heat generation, the infrared detector 6,
The outgas 12 adhering and frozen on the heat radiating surface 7'of the first cooling plate, the mirror surface 8'of the reflecting plate, and the heat radiating surface 9'of the second cooling plate is evaporated to cause the space 50 side, that is, the arrows C ', D',
Disperses in the E'and F'directions. Since the deterioration of the infrared transmittance of the light receiving surface of the detector 6 is also detected by a monitor (not shown) provided in the control device 30, the function recovery measures may be taken by an equivalent means. Also,
In the above-described embodiment, the case where three kinds of heaters are provided has been described, but a single heater may be attached to one of the cooling plate 7 or the reflection plate 8 for heating.

(g) Effects of the Invention As described in detail above, in short, the present invention provides a heater to a part of the radiative cooler so that the outgas attached to the radiative cooler can be accurately diffused to outer space. The effect on restoring the cooling function is great. Further, by using this heater, the temperature of each part in the space chamber can be freely set, so that the simulation on the ground can be easily performed. This heater can also be used for baking the heat insulating material 11, which is extremely useful for improving the cooling performance.

[Brief description of drawings]

FIG. 1 is a side sectional view showing the structure of a conventional radiation cooler, and FIG.
FIG. 3 is a side sectional view showing the structure of an embodiment of the radiation cooler according to the present invention, and FIG. 3 is a block diagram for explaining the operation. In the drawings, 1 is the satellite body, 2 is the side of the satellite body, 3 is the earth, 4 is infrared, 5 is a mirror, 6 is an infrared detector, 7 is a first cooling plate, and 7'is heat radiation from the first cooling plate. Surface, 8
Is a reflecting plate, 8'is a reflecting mirror surface, 9 is a second cooling plate, 9'is a radiating surface of the second cooling plate, 10 is a shield plate, 11 is a heat insulating material,
12 is outgas, 13 is a first cooling plate heater, 14
Is a reflection plate heater, 15 is a second cooling plate heater, 2
Reference numeral 0 is a heater power source, 30 is a control device (ground station), and 40 is a radiation cooler equipped with a first cooling plate 7, a reflecting plate 8, a second cooling plate 9 and a shield plate 10, respectively.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Tsurumi 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Inventor Ryuichi Ueda 1015, Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Inside Fujitsu Limited ( 72) Inventor Tetsuo Tanaka 3-16-13 Oyamadai, Setagaya-ku, Tokyo

Claims (1)

[Claims] 1. An infrared detector (6) mounted on an artificial hygiene body (1) for detecting incident infrared rays (4), and the infrared detector.
A first cooling plate (7) attached with (6) for cooling the infrared detector (6) by heat radiation to outer space (50);
A reflector plate formed so as to be insulated from the cooling plate (7) and expand in a funnel shape from the outer peripheral edge of the first cooling plate (7) to the outer space side (50) side.
(8), a second cooling plate (9) extending further outward than the outer peripheral edge of the reflection plate (8), the second cooling plate (9) and the first cooling plate
(7) is insulated from the outer periphery of the second cooling plate (9) and extends outward in the outer space side in a funnel shape, and the infrared detector (6), the first cooling plate (7), A shield plate (10) covering the reflection plate (8) and the second cooling plate (9), and at least one of the first cooling plate (7), the reflection plate (8) and the second cooling plate (9) Heater (1) to dissipate outgas (12)
A radiation cooler characterized by being provided with (3), (14) and (15).