JPH03227800A - Temperature control device of lunar vehicle - Google Patents

Abstract

PURPOSE:To retain an apparatus on board at a designated temperature at a low cost without pollution by fitting an apparatus on board, the temperature is controlled in a lunar vehicle to a heat accumulator, and connecting a radiator having a heat pipe embedded in the inner surface thereof and the above heat accumulator to each other by plural heat conduction paths. CONSTITUTION:During the night of the lunar surface, the temperature of a car body 4 of a lunar vehicle is lowered by radiation cooling, and the thermal energy of an apparatus 1 on board and a heat accumulator 2 where the apparatus is installed is transmitted to a radiator 8 through a thermal switch 6 and heat pipes 5, 7. Accordingly, the temperature of the apparatus 1 on board is kept at a melting point of the heat accumulator 2, so that the temperature of the apparatus 1 on board can be kept at a melting point even during the night. On the other hand, during the daytime of the lunar surface, the temperature of the car body rises, and the apparatus 1 on board is caused to generate heat by itself when the power is applied. Whereupon, the thermal energy is transmitted to the radiator 8 through a heat accumulator 2 as described above. Accordingly, the thermal energy is emitted in the space to prevent the temperature rise of the apparatus 1 on board.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a temperature control device for a lunar rover, and in particular to a temperature control device for a lunar rover that has daytime heat dissipation and nighttime heat retention functions in a self-propelled lunar rover. The present invention relates to a temperature control device.

[Conventional technology]

The first self-propelled vehicle for lunar exploration was put into practical use in the Soviet Union. Lunokhod, which made a soft landing on the moon in 1970 on board Luna 17, and 19 on board Luna 21.
Lunokhod 2 made a soft landing on the moon in 1973, and no self-propelled lunar exploration vehicle has been sent to the moon since then. As is well known, the moon is a celestial body that has day and night cycles every 29.5 days and has no atmosphere. For this reason, the surface temperature of the moon varies dramatically between day and night, and at noon on the equator,
The temperature rises to 00K, and just before dawn it drops to 80K.

Lunokhod and Lunokhod 2 will land in the Rainy Sea and the Sunny Sea, respectively, and although both locations are at relatively high latitudes, they will be exposed to the thermal environment of the lunar surface.

Previously, this type of lunar rover's temperature control system had a built-in nuclear heater to protect onboard equipment from low temperatures at night.

[Problem to be solved by the invention]

The conventional temperature control system for the lunar rover described above uses a nuclear heater to maintain the temperature of onboard equipment at night. The development of nuclear heaters has the disadvantage of being costly, since safety measures are required for the production and procurement facilities of nuclear heaters.

The purpose of the present invention is to maintain the onboard equipment for lunar surface exploration within a certain temperature range by using materials that change depending on the temperature difference between daytime and nighttime, and by controlling the temperature entirely with passive materials. An object of the present invention is to provide a temperature control device for a trolley.

[Means to solve the problem]

The temperature control device for a lunar rover of the present invention is a temperature control device for a lunar rover that controls the temperature of equipment mounted inside the lunar rover, and includes a heat storage device to which the equipment is attached and a heat storage material stored, and a solar-reflection device. a radiator having a solar reflective element with good radiation and infrared emissivity on its surface and a heat vibrator embedded in its inner surface; and a heat conduction controller having a plurality of heat conduction paths connecting the heat storage device and the radiator. , a thermal blanket with radiant heat insulation applied to the inner surface of the device and the lunar rover.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. 1st
In the figure, onboard equipment 1 is attached to a heat storage 2, which is fixed to a vehicle body 4 by a support 3 made of a heat insulating material, such as glass fiber reinforced plastic. The heat pipes 5 (two in the figure) are vacuum-sealed with a working fluid such as ammonia, one end is connected to the heat storage device 2, and the other end is connected to the thermal switch 6. The heat pipe 7 (two in the figure) is vacuum-filled with a working fluid such as ammonia, like the heat pipe 5, and one end is connected to the thermal switch 6. The other end is connected to the radiator 8.The thermal switch 6 has a function of disconnecting or connecting the heat conduction path depending on the temperature of the heat pipe 5, and the thermal switch 6 has a function of disconnecting or connecting the heat conduction path depending on the temperature of the heat pipe 5. Then, form a heat conduction path,
The heat pipe 5 and the heat pipe 7 are in a good heat conduction state, and when the temperature is lower than a preset temperature, the heat conduction path is cut off, and the space between the heat pipe 5 and the heat vibrator 7 is insulated.

The radiator 8 is fixed to the vehicle body 4 by a support 9 made of a heat insulating material. Onboard equipment 1 and heat storage device 2
is covered by a thermal blanket 10, and the vehicle body 4 is covered with a thermal blanket 10.
and is radiantly insulated. Thermal blankets 10 are attached in multiple layers to the inner surface of the vehicle body 4, and gaps are provided between the multiple layers of thermal blankets 10.
Radiant insulation is provided between the inside of the vehicle and the inside of the vehicle. Figure 2 shows the first
FIG. 2 is a configuration diagram of a thermal blanket 10 which is a main part of the illustrated embodiment. In the figure, a thermal blanket 10
The radiation shield 11 is made of metal such as aluminum deposited on a plastic film, and the separator 12 is made of a material with excellent heat insulation properties, such as Nomex, in the form of a mesh.
are alternately stacked on top of each other, and the radiation shield 11 having a metal surface with a low infrared emissivity is multilayered to make radiation insulation effective. FIG. 3 shows a thermal blanket 10 on the inner surface of the vehicle body 4, which is the main part of the embodiment shown in FIG.
FIG. In the figure, the beams 13 made in a lattice shape have a multilayer structure, and a thermal blanket 10 is attached to each layer of beams 13 with threads 14.

The beams 13 are made of a material with excellent heat insulation properties such as glass fiber reinforced plastic, and each layer of beams 13 is fixed to the vehicle body 4. A gap for radiant heat insulation between each thermal blanket is maintained by a beam 13. Figure 4 shows
2 is a configuration diagram showing details of a heat storage device 2, which is a main part of the embodiment shown in FIG. 1. FIG. In the figure, the heat storage device 2 includes a lid 15, a case 16, heat exchange fins 17, and a heat storage material 18. The lid 15 and the heat exchange fins 17 are made of a metal with good thermal conductivity such as aluminum, and the heat storage material 18 is sealed by the lid 5 and the case 16.

The heat storage material 18 is a substance such as water, which has a large heat of fusion when changing from a solid phase to a liquid phase and has a melting point close to room temperature. The heat exchange fins 17 are connected to the lid 15 by explosion welding or the like with good thermal conductivity, and are always immersed in the heat storage material 18. The mounted device 1 is attached to a lid 15, and the lid 15 is connected to one end of the heat pipe 7. FIG. 5 is a configuration diagram showing details of the radiator 8, which is the main part of FIG. 1, and FIG. 6 is a side view of the main part of FIG. 1, mainly the attachment part of the radiator heat pipe. First, in FIG. 5, the radiator 8 consists of one panel made of a material with good thermal conductivity such as aluminum, a heat pipe 20 embedded inside the panel 19, and a heat pipe 20 attached to the surface of the panel 19 with adhesive. The solar light reflecting element 21 has characteristics of low solar absorption and high infrared emissivity. The heat pipes 20 are vacuum-sealed with a working fluid such as ammonia, and a large number of such heat pipes 20 are arranged in parallel throughout the interior of the panel 19. One end of every heat pipe 20 is
Two of the four heat pipes 7 provide a good thermal connection, and the other end of the heat pipe 7 has a good thermal connection with the remaining two heat pipes 7. The four heat pipes 7 are connected to bent thermal switches 6 at four corners of one panel, respectively, as shown in FIG. The sunlight reflecting element 21 is made of a transparent glass plate with silver vapor deposited on one side, and the characteristics of the glass surface side include low sunlight absorption rate and light and infrared radiation emissivity.

Next, the operation of this embodiment will be explained. The lunar surface is in a high vacuum, and during the day the lunar rover receives direct sunlight and reflected light from the lunar surface, as well as heat radiation from the lunar surface, resulting in high temperatures. On the other hand, at night, it receives only a small amount of heat radiation from the lunar surface, and is essentially left at temperatures close to absolute zero. In such a thermal environment, the thermal blanket 10 is made by stacking radiation shields 11 and separators 12 alternately, as shown in FIG. 2, but since each layer is in contact with each other, heat conduction occurs in the direction across the layers. , this value cannot be ignored in general. In order to eliminate this conduction, thermal blankets 10 are fixed to each layer of the layered beam 13 with threads 14 as shown in FIG. 3, and gaps are provided between each thermal blanket 10. Furthermore, in order to improve the radiation insulation effect, a thermal blanket 10 is also arranged between the mounted equipment 1 and the heat storage device 2.

Now, it is assumed that the heat storage material 18 of the lunar rover is completely melted during the day and remains in a liquid phase at night, and that the power to the onboard equipment 1 is turned off at night. The temperature of the vehicle body 4 gradually decreases at night due to the action of radiation cooling, and the thermal energy leaking from the surfaces of the on-board equipment 1 and the heat storage device 2 to the vehicle body 4 increases accordingly. On the other hand, the temperature of the radiator 8 also decreases due to the action of radiation cooling, and the thermal energy of the mounted equipment 1 and the heat storage device 2 is transmitted to the radiator 8 while the thermal conduction path of the thermal switch 6 is connected. This is because the working fluid in the heat pipes 5 and 7 concentrates on the lid 15 side and the thermal switch 6 side due to the moon's gravity, so it receives thermal energy from the lid 15 and becomes steam. This steam is the thermal switch 6
It is cooled on the side and returns to liquid form. This is because a state of good heat conduction is achieved by repeating this process. The thermal energy of the heat storage material 18 is conducted to the case 16 and leaks from the surface of the case 16 to the vehicle body 4, and is also transferred to the lid 15 via the heat exchange fins 17, and is transferred to the heat pipe 5, thermal switch 6, heat pipe 7, and radiator. 8, the temperature of the heat storage material 18 rapidly decreases until the heat conduction path of the thermal switch 6 is cut off. Since the operation of switching the heat conduction path of the thermal switch 6 from the connected state to the disconnected state depends on the temperature of the heat pipe 5, the switching operation setting temperature of the thermal switch 6 is determined in advance from the change temperature of the liquid phase of the heat storage material 18. By keeping the temperature high, heat leakage from the heat storage material 18 to the radiator 8 is reduced before the heat storage material 18 undergoes a phase change from a liquid phase to a solid phase. As a result, the thermal energy of the heat storage material 18 is gradually lost by being conducted to the case 16 and flowing out from the case 16 to the vehicle body 4, and by the amount flowing from the surface of the lid 15 and the surface of the mounted equipment 1 to the vehicle body 4. The temperature of the heat storage material 18 reaches its melting point. Due to this flow of thermal energy, the temperature of the on-board equipment 1 changes until all of the heat storage material 18 changes from the liquid phase to the solid phase.
Since the temperature is maintained at the melting point of the heat storage material 18, the temperature of the mounted equipment 1 can be maintained at the melting point of the heat storage material 18 even at night.

Next, at dawn on the moon, the car body 4 and radiator 8
begins to receive direct sunlight and reflected light from the moon surface, and when the temperature of the vehicle body 4 reaches the melting point of the heat storage material 18, heat begins to flow from the vehicle body 4. The radiator 8 absorbs solar energy in accordance with the solar absorption rate of the solar reflective element 21, and the energy is transmitted to the panel 19, the heat pipe 20, and the heat pipe 7 in order, and the heat pipe 7.20, which is frozen during the night, is activated. Dissolve the liquid and resume normal operation. On the other hand, when the onboard equipment 1 is powered on and generates self-heating, this thermal energy is
It is directly transmitted to the heat storage material 18 in the heat storage device 2. Therefore, when the heat storage material 18 melts, the temperature of the heat storage material 18 starts to rise, and this temperature is transmitted to the thermal switch 6 through the heat pipe 5. The temperature of the heat pipe 5 is determined by the thermal switch 6
When the operating point is reached, the thermal switch 6 connects the beat vibro and the heat pipe 7 with good heat conduction.

Therefore, the self-heating of the onboard equipment 1 is caused by the sunlight reflecting element 21.
The temperature of the onboard equipment 1 is prevented from increasing by sequentially transmitting the information to the onboard equipment 1 and releasing it into outer space. The temperature of the sunlight reflecting element 21 is
The sum of the thermal energy transmitted from inside the vehicle body and the solar energy absorbed by the surface of the solar reflective element 21 is determined to be equal to the energy emitted from the surface of the solar reflective element 21 into space as infrared rays. Therefore, by appropriately selecting the area, sunlight absorption rate, and infrared emissivity of the sunlight reflecting element 21, the temperature of the mounted device 1 can be controlled to a predetermined value.

When the lunar rover travels during the day and the vehicle body 4 is tilted according to the inclination of the lunar surface, the working fluid in the heat pipe 20 is concentrated at one end. However, since the heat pipe 7 is inclined, the working fluid always accumulates on the thermal switch 6 side, and is heated by the heat pipe 7 to appropriately control the temperature of the thermal switch 6, so that the heat is finally dissipated from the panel 19. be done.

〔Effect of the invention〕

As explained above, the present invention utilizes the phase change energy of the heat storage material of the heat storage device, and further controls the temperature with a heat pipe, a thermal switch, and a solar reflective element, so that the system is constructed entirely of passive materials. ing. Therefore, it is possible to provide a temperature control device for a lunar rover that is free from pollution and is inexpensive.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a thermal blanket of the main part of the embodiment of FIG. 1,
Fig. 3 is a partial perspective view of the main part of Fig. 1, Fig. 4 is a block diagram of the heat storage device of the main part of Fig. 1, Fig. 5 is a block diagram of the radiator of the main part of Fig. The figure is a side view of the main part of FIG. 1. 1... Mounted equipment, 2... Heat storage device, 3... Support, 4... Vehicle body, 5, 7.20... Heat pipe, 6
...Thermal switch, 8...Radiator, 9...
・Support, 10... Thermal blanket, 11・
...Radiation shield, 12...Separator, 13...
Beam, 14... Thread, 15... Lid, 16... Case, 17... Heat exchange fin, 18... Heat storage material, 19
... Panel, 21... Solar reflective element.

Claims (1)

[Scope of Claims] 1. A temperature control device for a lunar rover that controls the temperature of equipment mounted on the lunar rover, including a heat storage device to which the equipment is attached and which stores a heat storage material, solar reflectance, and infrared radiation. a radiator having a solar reflective element with high efficiency on its surface and a heat pipe embedded in its inner surface; a heat conduction controller in which the heat storage device and the radiator are connected by a plurality of heat conduction paths; the device; A temperature control device for a lunar rover, comprising: a thermal blanket having a radiation heat-insulating effect attached to the inner surface of the lunar rover. 2. The heat conduction controller includes a plurality of first heat pipes having one end fixed to the heat storage device and the other end fixed to a thermal switch that opens and closes a heat conduction path at a predetermined temperature, and a plurality of first heat pipes fixed to the thermal switch. The temperature control device for a lunar rover according to claim 1, further comprising a plurality of second heat pipes having one end fixed and the other end fixed to the radiator. 3. The lunar rover according to claim 1, wherein the thermal blanket is formed in multiple layers of a radiation shield plate made of metal deposited on a plastic film and a separator made of a material with good heat insulation incorporated in a mesh shape. Temperature control device.