JP2019006264A - Space environment testing device, and operational method for space environment testing device - Google Patents

Abstract

To provide a space environment testing device capable of efficiently supplying a low temperature liquefied gas in a gaseous state or in a liquid state, into shrouds disposed inside a chamber.SOLUTION: A space environment testing device 1 comprises: a chamber 2; shrouds 3 disposed inside the chamber 2; a head tank 4 disposed at a position above the shrouds 3 in a vertical direction; a circulation path L1 in which a low temperature liquefied gas is circulated between the head tank 4 and the shrouds 3; and a control device 6 which holds supply pressure of the low temperature liquefied gas at a first target pressure value higher than atmospheric pressure, when supplying the low temperature liquefied gas in a liquid state to the shrouds 3, and which holds supply pressure of the low temperature liquefied gas at a second target pressure value higher than the first target pressure value, when supplying the low temperature liquefied gas in a gaseous state to the shrouds 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a space environment test apparatus and a method for operating a space environment test apparatus.

  As a device for simulating the cold and dark state of outer space, a space environment test device is known. Generally, a space environment test apparatus includes a chamber that can be evacuated to a high vacuum state and a shroud for keeping the inside of the chamber at a very low temperature in order to simulate a cold and dark state of outer space. Yes. Further, the inside of the shroud is painted with a black high emissivity paint, and a low-temperature liquefied gas is circulated.

  Patent Document 1 discloses a circulation method using a free boiling type (thermosyphon type) as a technique for circulating a low-temperature liquefied gas in a liquid state through a shroud in a chamber. Specifically, a head tank is provided at a position higher than the shroud in the chamber, one end of a pipe for circulating the circulating fluid is connected to the liquid phase part of the head tank, and the other end of the pipe is connected to the head after being supplied to the shroud. Connect to the gas phase of the tank. Thereby, the low-temperature liquefied gas in the liquid state circulates between the head tank and the shroud by utilizing the difference in liquid density caused by vaporizing with the shroud.

  Further, in the space environment test apparatus, when a test object in a chamber is heated, a low-temperature liquefied gas in a gaseous state is circulated through a shroud in the chamber, and this may be used as a heat source. That is, the low temperature liquefied gas in both the gaseous state and the liquid state may be circulated and supplied to the shroud in the chamber.

Japanese Patent No. 3946984

  By the way, in the space environment test apparatus, in order to perform the above-described thermal control, a long flow path by a shroud is formed on the inner wall of the chamber. And it was necessary to supply a large amount of low-temperature liquefied gas in a gaseous state or a liquid state into the shroud. However, in the conventional space environment test apparatus, it takes a few hours to bring the chamber into a predetermined temperature environment, and especially because the flash loss when supplying the low-temperature liquefied gas in the liquid state is large, the energy efficiency Improvement was desired.

  The present invention has been made in view of the above circumstances, and is a space environment test apparatus capable of efficiently supplying a gaseous or liquid low-temperature liquefied gas into a shroud provided in a chamber, and It is an object of the present invention to provide a method for operating a space environment test apparatus.

In order to solve this problem, the present invention has the following configuration.
[1] A chamber that holds the inner space in a high vacuum state;
A shroud provided inside the chamber;
A head tank provided at a position higher than the shroud in the vertical direction;
A circulation path for circulating a low-temperature liquefied gas between the head tank and the shroud;
In a state where the supply pressure of the low-temperature liquefied gas is maintained at the first target pressure value higher than atmospheric pressure, the low-temperature liquefied gas in the liquid state is supplied to the shroud, and the supply pressure of the low-temperature liquefied gas is A space environment test apparatus, comprising: a controller that supplies a low-temperature liquefied gas in a gaseous state to the shroud while being maintained at a second target pressure value higher than the first target pressure value.
[2] A low-temperature liquefied gas storage tank for storing the low-temperature liquefied gas;
A liquid supply path provided between the low-temperature liquefied gas storage tank and the head tank, and supplying the low-temperature liquefied gas in a liquid state to the head tank;
The gas supply path that is provided between the low-temperature liquefied gas storage tank and the circulation path and that supplies the low-temperature liquefied gas in a gas state to the circulation path on the primary side of the shroud, Space environment test equipment.
[3] It further comprises a signal line for electrically connecting the control device and the low-temperature liquefied gas storage tank,
The low-temperature liquefied gas storage tank has a pressure adjustment mechanism for adjusting the pressure in the low-temperature liquefied gas storage tank,
The control device maintains the pressure in the low-temperature liquefied gas storage tank at the first target pressure value when supplying the low-temperature liquefied gas in the liquid state to the shroud, and supplies the gas supply path with a low-temperature gas in the gas state. The space environment test apparatus according to [2], wherein when the liquefied gas is supplied, the pressure in the low-temperature liquefied gas storage tank is maintained at the second target pressure value.
[4] A liquid level gauge for measuring the position of the liquid level in the head tank;
The space environment test apparatus according to any one of [1] to [3], further including a signal line that electrically connects the control apparatus and the liquid level gauge.
[5] First and second low-temperature liquefied gas storage tanks that respectively store the low-temperature liquefied gas;
A liquid supply path provided between the first low-temperature liquefied gas storage tank and the head tank, and supplying the low-temperature liquefied gas in a liquid state to the head tank;
[1], comprising: a gas supply path that is provided between the second low-temperature liquefied gas storage tank and the circulation path, and that supplies a gaseous low-temperature liquefied gas to the circulation path on the primary side of the shroud. The described space environment test equipment.
[6] The first and second low-temperature liquefied gas storage tanks each have a pressure adjustment mechanism that adjusts the pressure in the first and second low-temperature liquefied gas storage tanks,
While the pressure in the first low-temperature liquefied gas storage tank is maintained at the first target pressure value,
The space environment test apparatus according to [5], wherein the pressure in the second low-temperature liquefied gas storage tank is maintained at the second target pressure value.
[7] A method of operating a space environment test apparatus for supplying a low-temperature liquefied gas in a gas state or a liquid state to a shroud provided inside the chamber and controlling the temperature in the chamber,
When cooling the inside of the chamber, supplying a low-temperature liquefied gas in a liquid state to the shroud while maintaining a supply pressure at a first target pressure value higher than atmospheric pressure,
When heating the inside of the chamber, a method for operating a space environment test apparatus for supplying a low-temperature liquefied gas in a gaseous state to the shroud while maintaining a supply pressure at a second target pressure value higher than the first target pressure value .

  According to the space environment test apparatus and the operation method of the space environment test apparatus of the present invention, the low-temperature liquefied gas in the gas state or the liquid state can be efficiently supplied into the shroud provided in the chamber. It is possible to improve the energy efficiency when the inside is set to a predetermined temperature environment.

1 is a system diagram showing a configuration of a space environment test apparatus according to an embodiment of the present invention. It is a schematic diagram for demonstrating the operating method of the space environment test apparatus which is one Embodiment of this invention. It is a systematic diagram which shows the structure of the space environment test apparatus which is other embodiment of this invention.

  Hereinafter, the configuration of a space environment test apparatus according to an embodiment to which the present invention is applied will be described in detail together with a method for operating the space environment test apparatus with reference to the drawings. In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

<Space environment test equipment>
First, an example of the configuration of a space environment test apparatus that is an embodiment to which the present invention is applied will be described. FIG. 1 is a system diagram showing a configuration of a space environment test apparatus according to an embodiment of the present invention. As shown in FIG. 1, a space environment test apparatus (hereinafter also simply referred to as “test apparatus”) 1 of the present embodiment includes a chamber 2, a shroud 3, a head tank 4, a circulation path L1, a liquid supply path L2, and a gas supply. A path L3, a low-temperature liquefied gas storage tank 5, and a control device 6 are provided and schematically configured.

The test apparatus 1 of this embodiment is an apparatus for simulating a cold and dark state in outer space. Specifically, the test apparatus 1 supplies a low-temperature liquefied gas in a gaseous state or a liquid state to a shroud 3 provided in the chamber 2 in a high vacuum state, and controls the inside of the chamber 2 to a target temperature. is there.
In the test apparatus 1 of the present embodiment, the case where liquefied nitrogen is used as the low temperature liquefied gas will be described as an example. However, the present invention is not limited to this, and other low temperature liquefied gases (liquid oxygen, liquid helium, etc.) May be used.

  The chamber 2 has a space inside (hereinafter sometimes referred to as “internal space”), and a device under test can be placed in the space. The internal space of the chamber 2 is communicated with a vacuum exhaust device (not shown), and the internal space can be maintained in a high vacuum state. The size and shape of the chamber 2 are not particularly limited, and can be appropriately selected according to the object to be tested placed in the internal space.

  The shroud 3 is provided inside the chamber 2 in order to heat or cool the internal space of the chamber 2. The shroud 3 is provided so as to cover part or all of the inner wall of the chamber 2. By supplying a low-temperature liquefied gas in a gas state or a liquid state to the shroud 3, the internal space of the chamber 2 and the test object placed in the internal space can be heated or cooled. Further, the shroud 3 may be branched into two or more lines inside the chamber 2 or may be one line.

  The head tank 4 is a container for temporarily storing the low-temperature liquefied gas supplied to the shroud 3. The head tank 4 is provided outside the chamber 2 and at a position higher than the shroud 3 in the vertical direction. In the head tank 4, the low-temperature liquefied gas is divided into a gas phase 4A and a liquid phase 4B. The capacity and shape of the head tank 4 are not particularly limited, and can be appropriately selected according to the size of the chamber 2 and the capacity of the shroud 3.

  The head tank 4 is provided with a liquid level gauge 7 for measuring the liquid level height of the liquid phase 4B inside the head tank 4. The liquid level gauge 7 is electrically connected to the control device 6 through a signal line C1. Thereby, the liquid level value of the liquid phase 4B measured by the liquid level gauge 7 can be transmitted to the control device 6 as an electric signal.

The circulation path L <b> 1 is a loop-shaped flow path provided for circulating the low-temperature liquefied gas between the head tank 4 and the shroud 3. Through this circulation path L1, the low-temperature liquefied gas in the gas state or the liquid state can be supplied from the head tank 4 to the shroud 3, and the low-temperature liquefied gas can be returned from the shroud 3 to the head tank 4.
In the circulation path L1, the path for supplying the low-temperature liquefied gas from the head tank 4 to the shroud 3 is branched into a gaseous low-temperature liquefied gas lead-out path L1A and a liquid low-temperature liquefied gas lead-out path L1B.

Specifically, one end of a gaseous low-temperature liquefied gas lead-out path L1A is connected to the top of the head tank 4. As a result, the gaseous low-temperature liquefied gas lead-out path L1A and the gas phase 4A of the head tank 4 communicate with each other, and the low-temperature liquefied gas in the gaseous state can be supplied from the head tank 4 to the shroud 3.
Further, one end of the liquid low-temperature liquefied gas lead-out path L1B is connected to the bottom of the head tank 4. As a result, the liquid low-temperature liquefied gas lead-out path L1B and the liquid phase 4B of the head tank 4 communicate with each other, and the liquid low-temperature liquefied gas can be supplied from the head tank 4 to the shroud 3.
The other end of the gaseous low-temperature liquefied gas lead-out path L1A and the other end of the liquid low-temperature liquefied gas lead-out path L1B merge at the junction P to form a circulation path L1.
The circulation path L1 branches again at the branch point Q, and supplies a low-temperature liquefied gas in a gas state or a liquid state to the shrouds 3 and 3, respectively.
The circulation path L <b> 1 is connected from the secondary side of the shrouds 3, 3 to a portion near the top of the head tank 4. As a result, the low-temperature liquefied gas after being supplied to the shroud 3 can be returned to the gas phase 4A portion of the head tank 4.

  The gaseous low-temperature liquefied gas lead-out path L1A has a shut-off valve 8, a pressure gauge 25, a thermometer 26, a blower 9, a temperature control unit 10, and a shut-off valve up to the junction P where it joins with the liquid low-temperature liquefied gas lead-out path L1B. 11 is provided.

  The shut-off valve 8 is electrically connected to the control device 6 via the signal line C2, and an open state or a closed state is selected according to a control signal from the control device 6. Specifically, the shut-off valve 8 is opened when a gaseous low-temperature liquefied gas is supplied from the gas phase 4 </ b> A of the head tank 4 to the shroud 3.

  The pressure gauge 25 and the thermometer 26 are electrically connected to the control device 6 through signal lines C15 and 16, respectively. Accordingly, the pressure value and temperature of the low-temperature liquefied gas in the gaseous low-temperature liquefied gas lead-out path L1A can be transmitted to the control device 6 as electric signals.

  The blower 9 and the temperature control unit 10 are electrically connected to the control device 6 via signal lines C3 and C4, respectively, and an operation state or a stop state is selected according to a control signal from the control device 6. Specifically, when it is desired to circulate the low-temperature liquefied gas in the gaseous state, the blower 9 is in the operating state, and when it is desired to adjust (temperature control) the temperature of the low-temperature liquefied gas in the gaseous state, the temperature adjusting unit 10 is in the operating state. .

  The shutoff valve 11 is electrically connected to the control device 6 via the signal line C5, and an open state or a closed state is selected according to a control signal from the control device 6. Specifically, the shut-off valve 11 is opened when the gaseous low-temperature liquefied gas lead-out path L1A is circulated in the gaseous state.

  Further, the gaseous low-temperature liquefied gas lead-out path L1A is branched at the branch point R from the exhaust path L7. A pressure control valve 24 is provided in the exhaust path L7.

  The pressure regulating valve 24 is electrically connected to the control device 6 through a signal line C14, and the opening degree is controlled from fully closed to fully opened in accordance with a control signal from the control device 6. In the test apparatus 1 of the present embodiment, the control device 6 controls the opening degree of the pressure adjustment valve 24 and the opening degree of the pressure adjustment valve 23 described later in conjunction with each other, and the suction pressure is adjusted according to the suction temperature of the blower 9. Since it can be adjusted, the density of the low-temperature liquefied gas in the gaseous state on the suction side of the blower 9 can be controlled to be constant. Thereby, a constant mass flow rate can be supplied from the blower 9 to the shroud 3.

The liquid low-temperature liquefied gas lead-out path L1B is provided with a shut-off valve 12 up to the junction P where it joins with the gaseous low-temperature liquefied gas lead-out path L1A.
The shut-off valve 12 is electrically connected to the control device 6 via the signal line C6, and an open state or a closed state is selected according to a control signal from the control device 6. Specifically, the shut-off valve 12 is in an open state when circulating a liquid low-temperature liquefied gas through the liquid low-temperature liquefied gas lead-out path L1B.

The circulation path L1 joined at the junction P is branched from the exhaust path L8 at a branch point V located further below the branch point P below the shroud 3.
The exhaust path L8 is provided mainly for extracting the liquid low-temperature liquefied gas stored in the shroud 3, the head tank 4, and the circulation path L1. A shutoff valve 27 is provided in the exhaust path L8.

  The shutoff valve 27 is electrically connected to the control device 6 via a signal line C17, and an open state or a closed state is selected according to a control signal from the control device 6. Specifically, the control device 6 controls the shut-off valves 8, 11, and 14 to be closed, the liquid level adjustment valve 21 to be closed, and the flow rate adjustment valve 13 to be open, and then the shut-off valve 27 is open. Thus, the liquid low-temperature liquefied gas stored in the shroud 3, the head tank 4, and the circulation paths L1 and L1B can be discharged out of the system.

The circulation path L1 branched at the branch point Q is provided with flow rate adjusting valves 13 and 13, respectively.
The flow rate adjusting valve 13 is electrically connected to the control device 6 via a signal line C7, and the opening degree is controlled from fully closed to fully open according to a control signal from the control device 6. Thereby, supply_amount | feed_rate of the low temperature liquefied gas of a gaseous state or a liquid state to the shroud 3 can be adjusted.

  The test apparatus 1 of the present embodiment is configured to provide a circulation path L1 for circulating the low-temperature liquefied gas between the shroud 3 and the head tank 4, and to provide the head tank 4 at a position higher than the shroud 3 in the vertical direction. . Thereby, in the test apparatus 1 of this embodiment, when circulating low temperature liquefied gas between the shroud 3 and the head tank 4, a free boiling type (thermo siphon type) can be employ | adopted.

  In the circulation path L1, an exhaust path L4 communicating with the gas phase 4A of the head tank 4 is provided. Specifically, the exhaust path L4 is provided to branch from the gaseous low-temperature liquefied gas lead-out path L1A at the branch point S on the primary side of the shut-off valve 8.

The exhaust path L4 is provided with a shut-off valve 14 and a heater 15 in order from the primary side.
The shut-off valve 14 is electrically connected to the control device 6 through a signal line C8. As a result, when the internal pressure of the head tank 4 (that is, the pressure in the gas phase 4A portion) rises above a specified value, the shutoff valve 14 that has received the control signal from the control device 6 is opened, and the inside of the head tank 4 The gaseous low-temperature liquefied gas is discharged to the outside through the exhaust path L4. Further, the low temperature liquefied gas can be warmed by the warmer 15 when passing through the exhaust path L4.

  The low-temperature liquefied gas storage tank 5 is a container for storing low-temperature liquefied gas supplied to the shroud 3 via the head tank 4. In the low-temperature liquefied gas storage tank 5, the low-temperature liquefied gas is divided into a gas phase 5A and a liquid phase 5B. The capacity and shape of the low-temperature liquefied gas storage tank 5 are not particularly limited, and can be appropriately selected according to the size of the chamber 2 and the capacity of the shroud 3.

  The low temperature liquefied gas storage tank 5 is provided with a pressure gauge 16 for measuring the pressure in the low temperature liquefied gas storage tank 5 and a pressure adjusting mechanism 17 for adjusting the pressure in the low temperature liquefied gas storage tank 5.

  The pressure gauge 16 is connected to the upper side of the low-temperature liquefied gas storage tank 5 so as to communicate with the gas phase 5A. The pressure gauge 16 is electrically connected to the control device 6 through a signal line C9. Thereby, the pressure value P (MPaG) in the low-temperature liquefied gas storage tank 5 measured by the pressure gauge 16 can be transmitted to the control device 6 as an electric signal.

  The pressure adjustment mechanism 17 includes a path L5 provided to communicate the gas phase 5A and the liquid phase 5B of the low-temperature liquefied gas storage tank 5, a vaporizer 18 provided in order from the liquid phase 5B side of the path L5, and a pressure The control valve 19 includes an exhaust path L6 provided to branch from the path L5 at a branch point T on the secondary side of the pressure control valve 19, and a pressure adjustment valve 20 provided in the exhaust path L6. . The configuration of the pressure adjustment mechanism 17 is an example, and is not limited to this.

  The vaporizer 18 is provided to supply the low-temperature liquefied gas in the gaseous state to the secondary side by heating and vaporizing the low-temperature liquefied gas in the liquid state supplied from the path L5.

The pressure regulating valve 19 is electrically connected to the control device 6 via a signal line C10, and the opening degree is controlled from fully closed to fully open according to a control signal from the control device 6. Thereby, supply_amount | feed_rate of the gaseous low temperature liquefied gas from the path | route L5 to the gaseous phase 5A of the low temperature liquefied gas storage tank 5 can be adjusted. In addition, by changing the pressure regulating valve 19 from the fully closed state to the open state, a low-temperature liquefied gas in a liquid state is introduced into the path L5 from the liquid phase 5B side, and is converted into a gaseous state by the vaporizer 18, then the gas phase 5A. By being led out to the side, the pressure in the low temperature liquefied gas storage tank 5 is increased.
That is, in the test apparatus 1 of the present embodiment, among the pressure gauge 16 and the pressure adjustment mechanism 17, the path L5, the vaporizer 18, the pressure adjustment valve 19, the signal lines C9 and C10, and the control device 6 A pressurizing mechanism is configured.

The pressure regulating valve 20 is electrically connected to the control device 6 via a signal line C11, and the opening degree is controlled from fully closed to fully open according to a control signal from the control device 6. Thereby, the discharge | release amount of the gaseous low temperature liquefied gas from the exhaust path L6 to the exterior can be adjusted. Note that the low-temperature liquefied gas storage tank is formed by releasing the low-temperature liquefied gas in the gas phase 5A portion in the low-temperature liquefied gas storage tank 5 from the exhaust path L6 by opening the pressure regulating valve 20 from the fully closed state to the open state. The pressure in 5 is reduced.
That is, in the test apparatus 1 of the present embodiment, the pressure gauge 16 and the pressure adjustment mechanism 17 include the path L5, the exhaust path L6, the pressure adjustment valve 20, the signal lines C9 and C11, and the control device 6. A decompression mechanism is configured.

  The liquid supply path L <b> 2 is provided between the head tank 4 and the low-temperature liquefied gas storage tank 5 that is a supply source of the low-temperature liquefied gas in order to supply the liquid low-temperature liquefied gas to the head tank 4. Specifically, the liquid supply path L2 is connected to the bottom of the low-temperature liquefied gas storage tank 5 so that one end communicates with the liquid phase 5B, and the other end of the head tank 4 communicates with the gas phase 4A. It is connected to the center or a portion above the center. Further, a liquid level adjustment valve 21 is provided in the liquid supply path L2.

  The liquid level adjustment valve 21 is electrically connected to the control device 6 via the signal line C12, and the opening degree is controlled from fully closed to fully open according to a control signal from the control device 6. Thereby, the supply amount of the low temperature liquefied gas in the liquid state from the low temperature liquefied gas storage tank 5 to the head tank 4 can be adjusted.

  The gas supply path L3 is provided between the low-temperature liquefied gas storage tank 5 serving as a supply source of the low-temperature liquefied gas and the circulation path L1 in order to supply the low-temperature liquefied gas in the gaseous state to the shroud 3. Specifically, the gas supply path L3 is connected to the bottom of the low-temperature liquefied gas storage tank 5 so that one end communicates with the liquid phase 5B, and the other end leads to the gaseous low-temperature liquefied gas constituting the circulation path L1. It is connected to the junction U between the shutoff valve 8 and the blower 9 in the path L1A. The gas supply path L3 is provided with a vaporizer 22 and a pressure regulating valve 23.

  The vaporizer 22 heats and vaporizes the liquid low-temperature liquefied gas supplied from the liquid phase portion of the low-temperature liquefied gas storage tank 5, thereby supplying the gaseous low-temperature liquefied gas to the gaseous low-temperature liquefied gas lead-out path L1A. Is provided to do.

  The pressure regulating valve 23 is electrically connected to the control device 6 via a signal line C13, and the opening degree is controlled from fully closed to fully opened in accordance with a control signal from the control device 6. Thereby, supply_amount | feed_rate of the gaseous low temperature liquefied gas from the low temperature liquefied gas storage tank 5 to the shroud 3 can be adjusted.

  As described above, the control device 6 includes the liquid level gauge 7, the blower 9, the temperature control unit 10, the pressure gauges 16 and 25, the shut-off valves 8, 11, 12 and 14, the flow rate adjustment valve 13, the pressure adjustment valve 19, 20, a liquid level adjusting valve 21, pressure adjusting valves 23 and 24, a thermometer 26, and signal lines C1 to C17 are electrically connected.

  The control device 6 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a control program. By executing the control program, the control device 6 functions as a device including a valve control unit (not shown), an acquisition unit, a set value information storage unit, and a determination unit. All or some of the functions of the control device 6 may be realized by using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). The control program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. Further, the control program may be transmitted / received via a telecommunication line.

Based on the control program determined by the determination unit, the valve control unit opens and closes the shut-off valves 8, 11, 12, and 14, the flow rate adjustment valve 13, the pressure adjustment valves 19, 20, 23, and 24, and the liquid level The opening degree of the regulating valve 21 is controlled.
The acquisition unit includes the liquid level value of the head tank 4 detected by the liquid level gauge 7, the pressure value P in the low-temperature liquefied gas storage tank 5 detected by the pressure gauge 16, the gas detected by the pressure gauge 25 and the thermometer 26. Detection data including any or all of the pressure value and temperature information of the low-temperature liquefied gas in the gas-like low-temperature liquefied gas lead-out path L1A is acquired.

The set value information storage unit is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The set value information storage unit includes a target value of the liquid level (liquid level value L), the first target pressure value P ₁ of the low temperature liquefied gas storage tank 5 when the liquid low temperature liquefied gas is supplied to the shroud 3, and the shroud. The second target pressure value P ₂ of the low temperature liquefied gas storage tank 5 when supplying the low temperature liquefied gas in a gaseous state to 3 and various target values and specified values such as the upper limit value P _H and the lower limit value P _L are stored. doing.
The determination unit refers to various target values and specified values, and determines an optimal control program based on the result of comparison calculation with each measurement value included in the detection data acquired by the acquisition unit.

Specifically, the control device 6 allows the pressure value P in the low-temperature liquefied gas storage tank 5 measured by the pressure gauge 16 to be the set first target pressure value P ₁ or the second target pressure value P _2. When it becomes less than the lower limit, a control signal is transmitted to the pressure regulating valve 19 to control from the fully closed state to the open state (predetermined opening). Thereby, the low-temperature liquefied gas in the liquid state is introduced into the path L5 from the liquid phase 5B side, and after being made into a gas state by the vaporizer 18, is led out to the gas phase 5A side, and the pressure in the low-temperature liquefied gas storage tank 5 is increased. To rise. Then, when the pressure value P measured by the pressure gauge 16 recovers to the first target pressure value P ₁ or the allowable lower limit value of the second target pressure value P ₂ , the control device 6 adjusts the pressure adjustment valve. A control signal is transmitted to 19 to control from the open state to the fully closed state.

On the other hand, the control device 6 determines that the pressure value P in the low-temperature liquefied gas storage tank 5 measured by the pressure gauge 16 exceeds the allowable upper limit value of the first target pressure value P ₁ or the second target pressure value P ₂ . In this case, a control signal is transmitted to the pressure regulating valve 20 to control from the fully closed state to the open state. As a result, the low-temperature liquefied gas in the gas phase 5A in the low-temperature liquefied gas storage tank 5 is released to the outside from the exhaust path L6, and the pressure in the low-temperature liquefied gas storage tank 5 decreases. Then, when the pressure value P measured by the pressure gauge 16 recovers below the allowable upper limit value of the first target pressure value P ₁ or the second target pressure value P ₂ , the control device 6 A control signal is transmitted to 20 to control from the open state to the fully closed state.

As the first target pressure P ₁ to be set in the controller (setting value information storage unit) 6, it is preferable that the value slightly higher than the atmospheric pressure. More specifically, the first target pressure _{P 1} may be a 0.1～0.3MPaG, it is preferable to 0.2～0.3MPaG. By the low-temperature liquefied gas storage tank 5 which supply pressure is held by the first target pressure value P ₁ through the liquid supply path L2 to supply a cryogenic liquefied gas in liquid state into the circulation path L1, the flash losses in the circulation path L1 Can be reduced. Therefore, the liquid low-temperature liquefied gas can be efficiently circulated between the shroud 3 and the head tank 4.

As the second target pressure value P ₂ to be set in the control device (setting value information storage unit) 6, it is preferable that the first value larger than the target pressure value P ₁ described above. Specifically, the second target pressure _{P 2} may be a 0.4～0.65MPaG, it is preferable to 0.5～0.65MPaG. By supplying low-temperature liquefied gas storage tank 5 which supply pressure is held in the second target pressure value P ₂ in the gas supply path L3 and the circulation path L1, to increase the supply amount of the low-temperature liquefied gas in a gaseous state into the shroud 3 be able to. Therefore, although the low-temperature liquefied gas in the gaseous state has a smaller specific heat than the liquid state, the temperature control in the chamber 2 can be performed efficiently.

<Operation method of space environment test equipment>
Next, an example of an operation method of the space environment test apparatus (that is, the test apparatus 1 described above) which is an embodiment to which the present invention is applied will be described. FIG. 2 is a time chart for explaining a method of operating the space environment test apparatus according to the embodiment of the present invention. In FIG. 2, the X axis indicates the time T from the start of operation of the test apparatus 1, and the Y axis indicates the pressure value P in the low temperature liquefied gas storage tank 5.

The operation method of the space environment test apparatus 1 according to the present embodiment (hereinafter also simply referred to as “operation method”) is to supply a low temperature liquefied gas in a gaseous state or a liquid state to a shroud 3 provided inside the chamber 2. In controlling the temperature in the chamber 2, when the inside of the chamber 2 is cooled, liquid low-temperature liquefied gas is supplied to the shroud 3 while maintaining the supply pressure at the first target pressure value P ₁ higher than atmospheric pressure. At the same time, when the inside of the chamber 2 is temperature-controlled, a method of supplying a gaseous low-temperature liquefied gas to the shroud 3 while maintaining the supply pressure at the second target pressure value P ₂ higher than the first target pressure value P _1. It is.

  Hereinafter, as an operation method of the present embodiment, (1) the supply state of the low-temperature liquefied gas in the liquid state is off (hereinafter referred to as “first state”), and (2) supply of the low-temperature liquefied gas in the liquid state A case where the mode is on (hereinafter referred to as “second state”) will be described as an example with reference to FIG.

(First state)
First, the operating method of this embodiment, until time t _1, performs the operation of the first state. In the operation of the first state, while maintaining the supply pressure to the second target pressure P _2, by supplying the low-temperature liquefied gas in a gaseous state to the shroud 3, regulating the temperature of the chamber 2. That is, the pressure of the low-temperature liquefied gas storage tank 5 is maintained at the second target pressure value P _2.

Specifically, in the operation in the first state, first, the control device 6 controls the shutoff valves 12 and 14 to be closed and the shutoff valves 8 and 11 to be opened. As a result, in the circulation path L1, the liquid low-temperature liquefied gas supply path L1B is closed, and the gaseous low-temperature liquefied gas lead-out path L1A is opened.
Next, the controller 6 performs PID control (feedback control) on the pressure in the low-temperature liquefied gas storage tank 5. As a result, the pressurizing mechanism and the depressurizing mechanism of the pressure adjusting mechanism 17 are in the operating state (ON state), and the second target pressure value P in which the pressure in the low-temperature liquefied gas storage tank 5 is the target value (set value; SV value). ₂ (for example, 0.6 MPaG).
Next, the flow rate adjusting valve 13 and the pressure adjusting valve 23 are controlled from the closed state to an appropriate opening degree by the control device 6. Thus, in a state where the pressure of the low-temperature liquefied gas storage tank 5 is held by the second target pressure P _2, the low-temperature liquefied gas in a gaseous state is supplied to the shroud 3.

(Second state)
Next, as shown in FIG. 2, when the time t ₁ has elapsed from the start of operation, the transition from the first state to the second state is started, and after the transition is completed at the time t ₆ , the time t ₇ Until then, the operation in the second state is performed.

First, in the operation in the transition state, the chamber 2 is cooled by supplying liquid low-temperature liquefied gas to the shroud 3 while reducing the supply pressure from the second target pressure value P ₂ to the first target pressure value P _1. To do.
Incidentally, in the operating method of this embodiment, the transition state, the supply of low-temperature liquefied gas in the liquid state to begin the shroud 3, the pressure of the low-temperature liquefied gas storage tank 5, from the second target pressure value P ₂ first shall means a state before transition to a target pressure value P _1.

Specifically, in the transition from the first state to the second state, first, the control device 6 controls the shutoff valves 8 and 11 to be closed and the shutoff valves 12 and 14 to be opened. As a result, in the circulation path L1, the gaseous low-temperature liquefied gas lead-out path L1A between the shut-off valve 8 and the shut-off valve 11 is shut off, and the liquid low-temperature liquefied gas supply path L1B is opened. In addition, the pressure in the shroud 3, the head tank 4, and the low-temperature liquefied gas supply path L1 is released outside the system via L4, the shutoff valve 14, and the heater 15, and is reduced to atmospheric pressure.
Next, the flow rate adjusting valve 13 and the liquid level adjusting valve 21 are controlled from the closed state to an appropriate opening degree by the control device 6. Thereby, the low-temperature liquefied gas in a liquid state is supplied from the low-temperature liquefied gas storage tank 5 to the shroud 3 through the head tank 4.
In the operation in the transition state, the PID control by the control device 6 is stopped (OFF state) with respect to the pressure value P in the low-temperature liquefied gas storage tank 5. That is, the pressurizing mechanism and the depressurizing mechanism of the pressure adjusting mechanism 17 are in a stopped state (OFF state).
On the other hand, at the initial stage of the operation in the transition state, it is necessary to supply a large amount of low-temperature liquefied gas from the low-temperature liquefied gas storage tank 5 to the shroud 3 through the head tank 4 in order to cool the inside of the chamber 2. The pressure value P in the low-temperature liquefied gas storage tank 5 naturally decreases as the liquid phase 4B of the head tank 4 and the liquid phase 5B of the low-temperature liquefied gas storage tank 5 are consumed.

  As described above, in the operation method of the present embodiment, in the transition state operation, the supply of the liquid low-temperature liquefied gas to the shroud 3 is started with the PID control stopped, and the low-temperature liquefied gas storage tank 5 Compared with the case where the pressure value P in the low-temperature liquefied gas storage tank 5 is controlled by forcibly discharging the low-temperature liquefied gas in the gaseous state from the exhaust path L6 in order to operate so that the pressure value P naturally decreases. The consumption of low-temperature liquefied gas can be reduced.

By the way, since the operation in the transition state is basically performed in a state where the PID control is stopped, the pressure value P in the low temperature liquefied gas storage tank 5 is not constant and varies depending on the operation state of the test apparatus 1. It will be.
Therefore, a case will be described in which an abnormal increase or decrease in the pressure value P in the low-temperature liquefied gas storage tank 5 occurs during operation in the transition state.

First, during the transition state operation, at time t _2, the case will be described in which abnormal rise in the pressure value P of the low-temperature liquefied gas storage tank 5 has occurred.
When the pressure value P of the low-temperature liquefied gas storage tank 5 as measured by the pressure gauge 16 has exceeded only large upper pressure limit P _H second target pressure value a slight value than P ₂ (αMPa), low-temperature liquefied gas storage tank 5 Pressure control is performed so that the pressure value P of the inside drops quickly.
Specifically, carried out by the control device 6, the second target pressure P ₂ the target value (SV value) and the PID control (feedback control). That is, the decompression mechanism of the pressure adjustment mechanism 17 is in an operating state (ON state), and the opening degree of the pressure adjustment valve 20 is controlled, so that a part of the gas phase 5A of the low temperature liquefied gas storage tank 5 is externally connected from the exhaust path L6. Is discharged.
The implementation of the pressure control, at time t _3, when the pressure value P of the low-temperature liquefied gas storage tank 5 falls below the upper pressure limit P _H, stopping the PID control.

Then, during the transition state operation At time t _4, the explanation for the case where abnormal drop in pressure value P of the low-temperature liquefied gas storage tank 5 has occurred.
When the pressure value P in the low-temperature liquefied gas storage tank 5 measured by the pressure gauge 16 exceeds the lower pressure limit P _L that is slightly smaller than the first target pressure value P ₁ (β MPa), the low-temperature liquefied gas storage tank 5 The pressure control is performed so that the pressure value P of the pressure increases rapidly.
Specifically, carried out by the control device 6, the first target pressure value P ₁ of the target value (SV value) and the PID control (feedback control). That is, the pressurization mechanism of the pressure adjustment mechanism 17 is in an operating state (ON state), and the opening degree of the pressure adjustment valve 19 is controlled, so that a part of the liquid phase 5B of the low-temperature liquefied gas storage tank 5 is the vaporizer 18. Vaporized and supplied from the path L5 to the gas phase 5A.
The implementation of the pressure control, at time t _5, when the pressure value P of the low-temperature liquefied gas storage tank 5 exceeds the pressure limit value P _L, stopping the PID control.

By the way, at the end of the operation in the transition state, the cooling in the chamber 2 proceeds and the liquid gradually accumulates in the shroud 3, so that the supply amount of the low-temperature liquefied gas to the shroud 3 decreases. As a result, the liquid low-temperature liquefied gas supplied from the low-temperature liquefied gas storage tank 5 accumulates in the head tank 4 to form a liquid phase 4B.
Then, at time t _6, when the value of the liquid level of the liquid phase 4B in the head tank 4, as measured by the level gauge 7 has a pre-control unit 6 set the liquid level value L or more, transition state Is completed, and the low-temperature steady operation in the second state is started.

In the operation of the second state, while maintaining the supply pressure to the first target pressure value P _1, and supplies a low-temperature liquefied gas in the liquid state in the shroud 3, to cool the inside of the chamber 2. That is, the pressure of the low-temperature liquefied gas storage tank 5 is maintained at the first target pressure value P _1.

Specifically, in the operation in the second state, the control device 6 performs PID control (feedback control) on the pressure in the low-temperature liquefied gas storage tank 5. As a result, the pressurizing mechanism and the depressurizing mechanism of the pressure adjusting mechanism 17 are in the operating state (ON state), and the pressure in the low-temperature liquefied gas storage tank 5 is maintained at the first target pressure value P ₁ (for example, 0.3 MPaG). The
Moreover, the opening degree of the flow regulating valves 13 and 21 is appropriately controlled by the control device 6. Thus, with the pressure value P of the low-temperature liquefied gas storage tank 5 is held by the first target pressure value P _1, low-temperature liquefied gas in the liquid state is supplied to the shroud 3.

(First state)
Next, as shown in FIG. 2, when it becomes time t _7, and again starts to shift to the first state from the second state, the operation of the first state until a predetermined time. In this case, first, a step of removing the liquid low-temperature liquefied gas stored in the shroud 3, the head tank 4, and the circulation path L1 is performed.

  Specifically, first, the control device 6 controls the shut-off valves 8, 11, 14 to be closed, the liquid level adjustment valve 21 to be closed, and the flow rate adjustment valve 13 to be open. Next, by controlling the shut-off valve 27 located below the shroud 3 to be in an open state, the liquid low-temperature liquefied gas stored in the shroud 3, the head tank 4, and the circulation paths L1 and L1B is discharged out of the system. can do.

  In order to further improve energy efficiency, a low-temperature liquefied gas storage tank is obtained by extracting liquid low-temperature liquefied gas stored in the shroud 3, the head tank 4, and the circulation paths L1 and L1B using a path and means (not shown). 5 may be recovered.

  Next, after discharging the liquid low-temperature liquefied gas stored in the circulation path L1, the state shifts to the first state. Specifically, in the operation in the first state, first, the control device 6 controls the shutoff valves 12 and 14 to be closed and the shutoff valves 8 and 11 to be opened. As a result, in the circulation path L1, the liquid low-temperature liquefied gas supply path L1B is closed, and the gaseous low-temperature liquefied gas lead-out path L1A is opened.

Here, in the transition from the second state to the first state, the pressure in the low-temperature liquefied gas storage tank 5 is immediately PID-controlled by the control device 6. Thus, the pressure mechanism and a pressure reducing mechanism the operating state (ON state) of the pressure regulating mechanism 17, the pressure of the low-temperature liquefied gas storage tank 5 immediately been migrated to the second target pressure value P _2, is maintained. In the transition from the second state to the first state, the gas phase 5A of the low-temperature liquefied gas storage tank 5 is not discharged to the outside, so that pressure control can be performed immediately.

Next, the flow rate adjusting valve 13 and the pressure amount adjusting valve 23 are controlled from the closed state to an appropriate opening degree by the control device 6. Thus, in a state where the pressure of the low-temperature liquefied gas storage tank 5 is held by the second target pressure P _2, the low-temperature liquefied gas in a gaseous state is supplied to the shroud 3.

  As described above, according to the test apparatus 1 of the present embodiment, the supply pressure of the low-temperature liquefied gas is controlled to a pressure suitable for the gas state or the liquid state. The shroud 3 can be supplied. Therefore, the energy efficiency when controlling the inside of the chamber 2 to a predetermined temperature environment can be improved.

  Further, according to the test apparatus 1 of the present embodiment, the low-temperature liquefied gas storage tank 5 includes the pressure adjusting mechanism 17 having the pressure increasing mechanism and the pressure reducing mechanism, and the control device 6 controls the pressure adjusting mechanism 17. The supply pressure when supplying the low-temperature liquefied gas in the state and the supply pressure when supplying the low-temperature liquefied gas in the gas state can be switched. Thereby, since it is not necessary to provide several low-temperature liquefied gas storage tanks according to supply pressure, the whole apparatus can be reduced in size.

According to the operation method of the space environment test apparatus 1 of the present embodiment, when the inside of the chamber 2 is cooled, the supply pressure is maintained at the first target pressure value P ₁ higher than atmospheric pressure, while the shroud 3 is in a liquid state. supplies the cryogenic liquefied gas, when the temperature control heat the inside of chamber 2, while maintaining the supply pressure to the second target pressure P ₂ higher than the first target pressure value P _1, the low-temperature gaseous shroud 3 Since the liquefied gas is supplied, the energy efficiency when controlling the inside of the chamber 2 to a predetermined temperature environment can be improved.

  Further, according to the operation method of the present embodiment, the pressure control of the low-temperature liquefied gas storage tank 5 is stopped when the operation for supplying the low-temperature liquefied gas in the gas state is shifted to the operation for supplying the low-temperature liquefied gas in the liquid state. In this state, the supply of the low-temperature liquefied gas in the liquid state to the shroud 3 is started, and the operation is performed so that the pressure value P in the low-temperature liquefied gas storage tank 5 naturally decreases. Compared with the case where the pressure value P in the low temperature liquefied gas storage tank 5 is forcibly controlled by discharging the gas, the consumption of the low temperature liquefied gas can be reduced.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. In the test apparatus 1 in the above-described embodiment, as shown in FIG. 1, the case where the low-temperature liquefied gas in the liquid state is supplied and the case where the low-temperature liquefied gas in the gas state is supplied are stored in one low-temperature liquefied gas storage tank 5. The configuration in which the pressure value is controlled and operated by the control device 6 has been described as an example, but is not limited thereto.

For example, as shown in FIG. 3, it may be a test apparatus 201 including two or more low-temperature liquefied gas storage tanks 105 and 205 controlled in advance to different pressures.
Specifically, the test apparatus 201, the pressure of the first low-temperature liquefied gas storage tank 105, the pressure adjusting mechanism 117 are always held in a high first target pressure value P ₁ than the atmospheric pressure, a second low-temperature liquefied gas The pressure in the storage tank 205 is constantly held at the second target pressure value P ₂ higher than the first target pressure value P ₁ by the pressure adjusting mechanism 217.

In the test apparatus 201, the pressure adjustment mechanism 117 of the first low-temperature liquefied gas storage tank 105 and the pressure adjustment mechanism 217 of the second low-temperature liquefied gas storage tank 205 are not controlled by the control device 206. It is operated independently from the control. That is, in the test apparatus 201, the control unit 206, in a state in which the supply pressure of the low-temperature liquefied gas is stored in the first target pressure value P _1, and supplies a low-temperature liquefied gas in the liquid state in the shroud 3, low-temperature liquefied gas in a state where the supply pressure is held by the second target pressure value P _2, and supplies a low-temperature liquefied gas in a gaseous state to the shroud 3.

  Further, in the test apparatus 201, a liquid supply path L2 for supplying a low-temperature liquefied gas in a liquid state is provided between the first low-temperature liquefied gas storage tank 105 and the head tank 4, and the second low-temperature liquefied gas storage tank 205 and the circulation are provided. A gas supply path L3 for supplying a gaseous low-temperature liquefied gas is provided between the path (gaseous low-temperature liquefied gas lead-out path L1A) L1.

According to the test apparatus 201 having the above-described configuration, the case where the liquid-state low-temperature liquefied gas is supplied and the case where the gas-state low-temperature liquefied gas is supplied can be operated using separate low-temperature liquefied gas storage tanks. . That is, upon supplying a low-temperature liquefied gas in the shroud 3, a low-temperature liquefied gas storage tank 105 which is held by the first target pressure value P _1, and a low-temperature liquefied gas storage tank 205 which is held by the second target pressure P ₂ appropriately By switching, the low-temperature liquefied gas to be circulated in the circulation path L1 can be immediately changed without losing the low-temperature liquefied gas.

  In the test apparatus 1 of the above-described embodiment, the gaseous low-temperature liquefied gas lead-out path L1A that communicates with the gas phase 4A of the head tank 4 and the liquid low-temperature liquefied gas lead-out path L1B that communicates with the liquid phase 4B of the head tank 4 In the above description, the circulatory path L1 is formed by joining together as an example. However, the present invention is not limited to this. The gaseous low-temperature liquefied gas lead-out path L1A and the liquid low-temperature liquefied gas lead-out path L1B may be configured to form independent circulation paths without joining.

  In the test apparatus 1 according to the above-described embodiment, the configuration in which the head tank 4 is provided outside the chamber 2 has been described as an example. However, the configuration is not limited thereto. The head tank 4 may be provided at a position higher than the shroud 3 in the vertical direction, and may be provided inside the chamber 2.

  A space environment test apparatus and a method for operating the space environment test apparatus according to the present invention provide a space environment test apparatus and a space environment test apparatus for operating a space environment test apparatus by supplying a low-temperature liquefied gas in a gas or liquid state to a shroud in the chamber to control the temperature in the chamber. Have the possibility to use.

1,201 ... Space environment test equipment (test equipment)
2 ... Chamber 3 ... Shroud 4 ... Head tank 5 ... Low temperature liquefied gas storage tank 6, 206 ... Control device 7 ... Liquid level gauge 8, 11, 12, 14, 27 ... Shut-off valve 9 ... Blower 10 ... Temperature control unit 15 ... Addition Heater 13 ... Flow rate adjustment valve 19, 20, 23, 24 ... Pressure adjustment valve 21 ... Liquid level adjustment valve 16, 25 ... Pressure gauge 17, 117, 217 ... Pressure adjustment mechanism 18, 22 ... Vaporizer 26 ... Thermometer 105 ... low temperature liquefied gas storage tank (first low temperature liquefied gas storage tank)
205 ... low temperature liquefied gas storage tank (second low temperature liquefied gas storage tank)
L1 ... circulation path L1A ... gaseous low-temperature liquefied gas lead-out path L1B ... liquid low-temperature liquefied gas lead-out path L2 ... liquid supply path L3 ... gas supply path L4, L6-L8 ... exhaust path L5 ... path C1-C17 ... signal line

Claims (7)

A chamber for keeping the inner space in a high vacuum state;
A shroud provided inside the chamber;
A head tank provided at a position higher than the shroud in the vertical direction;
A circulation path for circulating a low-temperature liquefied gas between the head tank and the shroud;
In a state where the supply pressure of the low-temperature liquefied gas is maintained at the first target pressure value higher than atmospheric pressure, the low-temperature liquefied gas in the liquid state is supplied to the shroud, and the supply pressure of the low-temperature liquefied gas is A space environment test apparatus, comprising: a controller that supplies a low-temperature liquefied gas in a gaseous state to the shroud while being maintained at a second target pressure value higher than the first target pressure value. A low-temperature liquefied gas storage tank for storing the low-temperature liquefied gas;
A liquid supply path provided between the low-temperature liquefied gas storage tank and the head tank, and supplying the low-temperature liquefied gas in a liquid state to the head tank;
The gas supply path which is provided between the low-temperature liquefied gas storage tank and the circulation path, and supplies the low-temperature liquefied gas in the gaseous state to the circulation path on the primary side of the shroud. Space environment test equipment. A signal line for electrically connecting the control device and the low-temperature liquefied gas storage tank;
The low-temperature liquefied gas storage tank has a pressure adjustment mechanism for adjusting the pressure in the low-temperature liquefied gas storage tank,
The control device maintains the pressure in the low-temperature liquefied gas storage tank at the first target pressure value when supplying the low-temperature liquefied gas in the liquid state to the shroud, and supplies the gas supply path with a low-temperature gas in the gas state. The space environment test apparatus according to claim 2, wherein when the liquefied gas is supplied, the pressure in the low-temperature liquefied gas storage tank is maintained at the second target pressure value. A liquid level gauge for measuring the position of the liquid level in the head tank;
The space environment test apparatus according to any one of claims 1 to 3, further comprising a signal line that electrically connects the control device and the liquid level gauge. First and second low-temperature liquefied gas storage tanks for storing the low-temperature liquefied gas, respectively;
A liquid supply path provided between the first low-temperature liquefied gas storage tank and the head tank, and supplying the low-temperature liquefied gas in a liquid state to the head tank;
A gas supply path that is provided between the second low-temperature liquefied gas storage tank and the circulation path and supplies a low-temperature liquefied gas in a gaseous state to the circulation path on the primary side of the shroud. The described space environment test equipment. The first and second low-temperature liquefied gas storage tanks each have a pressure adjusting mechanism for adjusting the pressure in the first and second low-temperature liquefied gas storage tanks;
While the pressure in the first low-temperature liquefied gas storage tank is maintained at the first target pressure value,
The space environment test apparatus according to claim 5, wherein the pressure in the second low-temperature liquefied gas storage tank is maintained at the second target pressure value. A method for operating a space environment test apparatus that supplies a low-temperature liquefied gas in a gas state or a liquid state to a shroud provided inside the chamber, and controls the temperature in the chamber,
When cooling the inside of the chamber, supplying a low-temperature liquefied gas in a liquid state to the shroud while maintaining a supply pressure at a first target pressure value higher than atmospheric pressure,
When heating the inside of the chamber, a method for operating a space environment test apparatus for supplying a low-temperature liquefied gas in a gaseous state to the shroud while maintaining a supply pressure at a second target pressure value higher than the first target pressure value .

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