KR20010064451A - Fixture of heat vacuum chamber using shroud contact - Google Patents

Abstract

PURPOSE: A fixture for a heat vacuum chamber using shroud contact is provided to rapidly reach the wanted temperature of a test object by improving the efficiency of heat transfer, and reduce consumpted amount of liquid nitrogen and work time. CONSTITUTION: A fixture for a heat vacuum chamber using shroud contact includes test object rests(1,2) having a curved surface equal to a shroud(8) and directly contacted with the shroud for inducing radiation, auxiliary blades(3,4) connected with the test object rests and oppositely formed to be coupled with the curved surface of the shroud by using thin metal, so that the temperature of a test object(9) promptly reaches desired temperature.

Description

Fixture of heat vacuum chamber using shroud contact

The present invention relates to a test assisting device (Fixture) that allows the test object to quickly reach the desired temperature during the space environment test in the thermal vacuum chamber, a space environmental test apparatus

The present invention relates to a test assistance apparatus for a thermal vacuum chamber using a shroud contact to shorten the test time by inducing heat conduction during heat exchange between a shroud, which is a heat exchanger, and a test article in the thermal vacuum chamber.

The thermal vacuum chamber is a representative device that simulates the vacuum and thermal environment, which is a space environment on the ground, and is an expensive equipment for performing thermal environment tests on satellites or parts thereof.

In general, in a vacuum environment of 1 × 10 ^-4 torr or less, heat transfer by convection is ignored and heat is transferred by radiation. Environmental tests are performed in a thermal vacuum chamber operated at a high vacuum of 10 ^-5 torr or less. In this case, unless a special jig is used, heat conduction due to heat radiation takes up most of the heat, and the heat transfer at cryogenic temperature is related to the absolute temperature quadratic value, so the ability is significantly reduced.

As a simple example, in heat conduction, the amount of heat transfer between a -100 ° C object and a -200 ° C object is equal to the heat transfer between a 100 ° C object and a 200 ° C object, but in a radiation, the heat transfer between a -100 ° C object and a -200 ° C object. The amount is 36 times smaller than the heat transfer amount between the 100 ° C object and the 200 ° C object, and the heat transfer due to heat radiation at cryogenic temperature becomes very weak.

Therefore, it is very difficult to improve the heat transfer ability in the cryogenic region without using the heat conduction.

In general, the thermal vacuum chamber uses liquid nitrogen (LN ₂ ) as a heat transfer refrigerant. The shortening of the test period is directly related to the reduction of the liquid nitrogen consumption, the reduction of working hours of workers, and the life of expensive equipment.

Conventional thermal vacuum chamber is a representative device that simulates the vacuum and thermal environment of the space environment on the ground as shown in Figure 1 is an expensive equipment for performing a thermal environment test for satellite or its components.

In a typical thermal vacuum chamber, the door 15 is installed and connected to the teflon 12 at the top of the beam 11 inside the shroud 8, which is a heat exchanger made of a liquid nitrogen pipe 14 used as a heat transfer refrigerant. Since the water support 13 is installed, most of the heat transfer from the shroud to the specimen is made by radiant heat.

This shape has its own meaning in simulating the space environment, but the thermal vacuum test for the part design verification or manufacturing technology verification requires too long test time, which requires expensive test costs and long test periods. It is polluted.

The present invention is intended to be used for a test in which the temperature range falls down to a cryogenic region under a high vacuum even in a relatively large structure such as a satellite solar panel or a satellite antenna.

It is to reduce the consumption of cryogenic refrigerant (liquid nitrogen or liquid helium) in the thermal vacuum chamber by shortening the test time by inducing heat conduction during heat exchange between the shroud and the specimen in the high vacuum environment of the thermal vacuum test.

The present invention is formed as a test specimen support having a curved surface such as a shroud in the thermal vacuum chamber to directly contact the shroud to induce heat conduction, and the auxiliary wing connected to the test specimen support using a thin metal to the shroud and the additional thermal conduction It is characterized by causing it.

1 is a perspective view of the door of the conventional thermal vacuum chamber separated

2 is a test support installation structure of a conventional thermal vacuum chamber

Figure 3 is a perspective view of the test aid of the present invention

Figure 4 is a perspective view of the test article mounted on the test aid of the present invention

Figure 5 is a state diagram installed in the shroud test aids of the present invention

* Explanation of symbols for the main parts of the drawings

1, 2: test object support 3, 4: auxiliary wing

5, 6: pedestal 7: brace

8: shroud 9: test article

10: bolt

The present invention is formed in a curved surface to fit the inner curved surface of the thermal vacuum chamber shroud (8) to the test object (9), such as a solar panel on the upper side to be fixed using a fixing member such as bolt 10 to be integral. Install the specimen support (1) (2) on both sides.

The auxiliary wings (3) (4) whose outer sides are curved to be fitted to protrude to the lower side of the test specimen support (1) (2) and to be fitted to the inner curved surface of the shroud (8) are installed on both sides.

The auxiliary wings (3) (4) were made of a thin steel plate that is easily deformed to improve contact with the inner curved surface of the shroud (8).

The use of a thin steel sheet provides flexibility in contact between the shroud 8 and the auxiliary wings 3 and 4, which may not be perfectly circular.

A pedestal 5, 6 is formed below the auxiliary wings 3, 4, and a brace 7 is formed below the pedestal 5, 6.

It is to prevent the test object 9 installed inside the shroud 8, which is a thermal vacuum chamber, from being used for a long time to reach a desired temperature during a thermal vacuum test that simulates a space environment.

Induce heat conduction from the shroud 8 which generates heat by the liquid nitrogen pipe 14 used as the heat transfer refrigerant.

The heat of the shroud 8, which is a heat exchanger, causes a lot of heat transfer by conduction between the specimens 9 through the specimen supports 1 and 2 so that the specimen 9 can be quickly heated to a desired temperature. To get there.

At this time, the auxiliary wing (3) (4) is to induce additional heat conduction with the circular shroud (8).

And the pedestal (5) (6) to concentrate the heat transfer through the auxiliary wings (3) (4) to the specimen support (1) (2).

In addition, the brace 7 serves to keep the structure of the symmetry intact and to uniform the temperature distribution of the left and right symmetry.

The test piece support (1) (2) and the pedestal (5) (6) and the support (7) are made of aluminum with good thermal conductivity and relatively light weight, and the auxiliary wings (3) and (4) are made of thin steel sheet, All components are anodized black to improve heat transfer by radiation and solve contamination problems in high vacuum.

The present invention prevents a significant drop in heat transfer effect only by radiant heat transfer in the cryogenic region when performing a thermal vacuum test on a relatively large object.

The present invention is to improve the heat transfer efficiency by the direct contact with the shroud by using the test object support and the auxiliary wing having a curved surface to be able to quickly reach the desired temperature.

The present invention reduces the liquid nitrogen consumption by shortening the test time, shortens the working hours of workers and extends the life of expensive equipment.

Claims (3)

In the thermal vacuum chamber of the shroud (8) is formed in a curved surface and the thermally tested by placing the test object (9) therein, The test piece support (1) (2) having the same surface as the shroud (8) is in direct contact with the shroud (8) to induce heat conduction, connected to the test piece support (1) (2) and using a thin metal Test assistant for the thermal vacuum chamber using the shroud contact, characterized in that to form the auxiliary wings (3) (4) symmetrically connected to the curved surface of the shroud (8) to quickly reach the desired temperature Device. 2. A test aid for a thermal vacuum chamber according to claim 1, wherein the auxiliary wings (3) (4) use a circular shroud (8) and a thin metal plate causing additional thermal conduction. According to claim 1, wherein the base (5) (6) formed on the lower side of the auxiliary wing (3) (4) is formed symmetrically, by connecting the lower side of the base (5) (6) with a brace (7) A test aid for thermal vacuum chambers using shroud contacts, characterized by providing a uniform temperature distribution.