JPS60179400A - Controller for heat of artificial satellite using electrochromic element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal control device for controlling the temperature of a predetermined surface of an artificial satellite.

Thermal louvers have traditionally been used as thermal control devices for artificial satellites, which automatically control radiant energy in the infrared region to optimize the temperature of the satellite.

FIG. 1 is a schematic diagram showing the outline of such a thermal louver. A plurality of blades 3 between frames 2 attached to a panel 1 are opened and closed by driving an actuator 4. The energy radiated from the panel l to the cover 5 is controlled by the degree to which the blade 3 is opened or closed. The cover 5 is exposed to outer space, and the energy reaching the cover 5 from the panel 1 is released from the cover 5 into outer space.

The drive source of the actuator 4 that drives the blade 3 includes:
Bimetal springs are generally used 1. -I'm Lale. The bimetal spring is strongly thermally coupled to the panel 1, and a torque is generated in accordance with the temperature of the panel 1, forming a mechanism for opening and closing the blade 3 via the shaft of the actuator 4.

Since such a thermal louver is mechanically constructed as described above, it has the disadvantage that its occupied volume and weight are large. In addition, the cover 5 has the function of preventing sunlight from directly entering the inside of the thermal louver and reducing the heat dissipation capacity, but it has the disadvantage that the heat dissipation capacity is halved compared to when there is no cover 5 when the sunlight does not enter the thermal louver. be.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat control device using an electrochromic element that reduces the occupied volume and weight and reduces the reduction in heat dissipation ability.

In order to achieve the above object, a thermal control device for an artificial satellite using an electrochromic element according to the present invention is provided by installing an electrochromic element on a thermal control panel of an artificial satellite, and adjusting the voltage applied to the electrochromic element according to conditions. The temperature control panel is configured to control the temperature of the heat control panel by changing the sunlight absorption rate and adjusting the absorption amount of sunlight energy incident on the heat control panel.

Embodiments of the present invention will be described in more detail below with reference to the drawings.

FIG. 2 is a perspective view of a thermal control panel according to the present invention, where 1 is a panel and 6 is an electrochromic element. The electrochromic element 61'i' is attached to a panel l such that thermal coupling between the two is increased, and this panel l is attached to an artificial satellite with the electrochromic element facing outer space.

FIG. 3 is a sectional view of an electrochromic device applied to the present invention. In the figure, 7 is a coverglass, 8 is a transparent electrode, 9 is a thin film of a substance exhibiting electrochromism such as WO3 or Ir(OH)rl, 10 is an ion conductive layer such as an electrolyte or dielectric, and 11 is a counter electrode. . In an electrochromic element using a reduced color forming substance such as WO3, the substance 9 exhibiting electrochromism is reduced by applying a voltage between the transparent electrode 8 and the counter electrode 10 so that the electrode 8 becomes negative. Color develops, and the absorption rate of sunlight incident on the coverglass 7 increases.

Further, by applying a voltage between the transparent electrode 8 and the counter electrode lO so that the voltage is positive, the substance 9 exhibiting electrochromism is oxidized and becomes transparent, and sunlight incident through the cover glass 7 is absorbed by the substance exhibiting electrochromism. The absorption rate of sunlight that passes through the cover glass 7 and is scattered by the ion conductive layer 10 and enters the cover glass 7 decreases.

In an electrochromic device using an oxidized color-forming substance represented by Ir(OH)n, there is a relationship between the polarity of the voltage applied between the transparent electrode 8 and the counter electrode 10 and the absorption rate of sunlight incident through the cover glass 7. This is the opposite of the case described above in which a reduced color forming substance represented by WO3 is used. By reversing the polarity of the voltage applied between the transparent electrode 8 and the opposing monopole lO in this manner, the sunlight absorption rate of the electrochromic element 6 changes. On the other hand, regarding the infrared radiation height, which is important as a heat dissipation property, the thermo-optical properties of the cover glass 7 on the surface of the electrochromic element are dominant, and since the cover glass 7 is a dielectric, its value is large, and the solar absorption rate is large. It has great heat dissipation characteristics regardless of the

FIG. 2 shows a plurality of electrochromic elements 6 having such functions arranged on the panel 1. In the same figure, when the temperature of the panel 1 decreases, if a voltage with a polarity that increases the sunlight absorption rate is applied between the electrodes of each electrocomic element 6, the electrocomic element will absorb more sunlight energy. The temperature of the panel 6 increases, and the temperature of the panel 1, which is strongly thermally coupled to the electrochromic element 6, also increases.

On the other hand, if the temperature of the panel 1 rises, if a voltage with a polarity that reduces the solar absorption rate is applied between the electrodes of each electrochromic element 6, the amount of solar energy absorbed decreases, and the electrochromic element 6 The temperature of element 6 and panel 1 decreases. By continuously performing the above operations, it is possible to control the temperature of the artificial satellite to a certain constant temperature.

FIG. 4 is a block diagram showing an actual example of a circuit for controlling an electrochromic element, in which 6 is an electrochromic element, 12 is a temperature sensor, 13 is a control circuit, and 14 is a reference signal source. Temperature sensor 12 is attached to panel 1 in FIG.
The output is input to the control circuit 13, and the control circuit 13 compares and judges the signal input from the reference signal source 14, and applies a voltage of polarity relative to the temperature detected by the temperature sensor 12 to the electrochromic element. 6 electrodes. In this way, the solar absorption rate of the electrochromic device can be controlled. Furthermore, if the temperature sensor 12 is attached to a certain part of the artificial satellite to be controlled, thermal control can be performed according to the temperature of that part.

As explained in detail above, the device in which the electrochromic device according to the present invention is attached to a panel can control the temperature by controlling the voltage applied to the electrodes of the device to change the sunlight absorption rate, and has a heat dissipation capacity. It also turned out to be excellent. Electrochromic devices are generally thin and lightweight. Therefore, by arranging electrochromic elements on a panel, it is possible to realize a heat control device that takes up a small volume and is lightweight, and that utilizes changes in sunlight absorption rate.

In general, materials that exhibit electrochromism are often inorganic compounds, and the parts that make up the device can also be made from inorganic materials. Suitable for use.

Such a thermal control device can be widely applied not only to artificial satellites but also to temperature control of devices that receive energy in the visible light region.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional thermal louver, and FIG. 2 is a perspective view of an embodiment of a thermal control panel according to the present invention. FIG. 3 is a cross-sectional view of an electrochromic element used in the present invention, and FIG. 4 is a block diagram of an embodiment of the control section of the apparatus of the present invention. 1... Panel 2... Frame 3... Blade 4... Actuator 5... Cover 6... Electrochromic element 7... Cover glass 8... Transparent electrode 9... Electrochromism Thin film 10 of the indicated substance...Ion conductive layer 11...
Counter electrode 12... Temperature sensor 13... Control circuit 1
4...Reference signal source

Claims (1)

[Claims] An electrochromic element is attached to a thermal control panel of an artificial satellite, and the voltage applied to the electrochromic element is adjusted according to conditions to change the solar absorption rate, thereby creating an absorption layer for solar energy incident on the thermal control panel. A thermal control device for an artificial satellite using an electrochromic element, characterized in that the temperature control oil of the thermal control panel is controlled by adjusting the temperature of the thermal control panel.