RU2369538C1 - Volume compensator for spacecraft liquid temperature control system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: according to the invention, the volume compensator has a case and bellows inside the case. The bellows, which are the main bellows, divide the inside of the case into two parts. There are extra bellows with a solid bottom and a cylindrical cup. The cup is integral with the solid bottom of the main bellows. The extra bellows are placed inside the main bellows in the cup, coaxially with the main bellows. The compensator can be used in temperature control systems of spacecraft, with large volume of liquid heat carrier, large mass-average temperature range and long duration of active existence on orbit.

EFFECT: larger compensated volume of liquid without increasing size of the compensator.

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Description

The invention relates to liquid temperature control systems (CTP), mainly spacecraft (SC).

The volume compensator is designed to receive the excess coolant volume from the STP liquid circuit and supply it back to the STR when there is a lack of coolant in it, as well as to store the coolant supply.

Volume Compensator provides:

- compensation of temperature changes in the volume of coolant;

- maintaining the working pressure in the liquid circuit STR;

- Compensation of coolant leaks from the liquid circuit under the existing leakage standards PAGE.

The excess coolant volume generated when the coolant temperature rises in the STP fluid circuit enters the fluid cavity and compresses the media separator of the volume compensator, and when the coolant temperature in the STR fluid circuit decreases, the separator of the media of the volume compensator stretches under the influence of the pressure of the compression substance and displaces the required amount of coolant in the fluid circuit PAGE, maintaining the pressure of the coolant at the point of connection of the volume compensator to the liquid circuit C R.

Volume compensators are known in which either an elastic membrane, for example rubber or metal bellows, is used as a media separator (see OST 92-9092-79 “Volume compensators for gas-liquid thermal control systems. Types and main parameters”).

The disadvantage of elastic separation membranes made on the basis of rubber is the high gas permeability of its surface, which leads to the saturation of the liquid with gas over time and, therefore, limits the time of normal operation of the STR KA. Separating elements made in the form of sealed bellows are free from these drawbacks, however, the design of the bellows does not allow full use of the entire internal cavity of the volume compensator, since the bellows in the compressed position occupies a significant volume, and fully stretched cannot displace, without residue, all liquid from the tank .

The volume of the liquid cavity of the volume compensator with the compressed and extended position of the bellows is called the “maximum” and “minimum” volume of the liquid cavity of the volume compensator, respectively.

The compensated volume of the volume compensator is defined as the difference between the maximum and minimum volume of the liquid cavity of the volume compensator. At the maximum volume of the liquid cavity of the volume compensator, i.e. with the bellows fully compressed, the displacement cavity of the volume compensator is minimal.

A known volume compensator (see OST92-9092-79, sheet 8, drawing 1). The compensated volume of such a volume compensator is 4.2 dm ³ , while the minimum volume of the displacement cavity of the volume compensator is 1.4 dm ³ and the minimum volume of the liquid cavity of the volume compensator is 2.8 dm ³ .

A known volume compensator (see 154.3641-000 TU "Volume compensator. Technical conditions", sheet 23, Fig. 2), which is selected as a prototype. Volume compensator 154.3641-000 is a cylindrical container with hemispherical bottoms, the internal cavity of which is divided by a hermetic bellows into two containers. One is connected to the STP liquid circuit, the other is filled with a displacement body (compression substance), for example, gaseous nitrogen OST 92-1577-78 or HFC 141B according to TU 2400-001-53268553-2000. The compensated volume of this compensator is 5.5 dm ³ , while the minimum volume of the displacing cavity is 1.4 dm ³ and the minimum volume of the liquid cavity is 3.5 dm ³ .

Therefore, in known volume compensators, compensated volumes do not exceed 55% of the total volume of the internal cavity.

The objective of the invention is to increase the compensated volume while maintaining the constant dimensions of the volume compensator.

The task is achieved by the fact that in the well-known expansion joint, consisting of a sealed bellows enclosed in a housing that divides the internal cavity of the volume expansion joint into two parts, an additional bellows is installed coaxially with it inside the bellows, placed in a cylindrical glass made in one piece with the movable bottom of the bellows .

The essence of the invention is illustrated by the drawing, which shows a General view of the proposed volume compensator at various positions of the bellows and additional bellows.

Positionally compensated volume is the following content:

1 - bellows;

2 - body compensator volume;

3 - the bottom of the bellows 1 volume compensator;

4 - the bottom of the housing 2 volume compensator;

5 - the moving bottom of the bellows 1;

6 - movable glass bellows 1;

7 - additional bellows;

8 - the bottom of the additional bellows 7;

9 - fitting for connecting the liquid cavity of the volume compensator to the liquid line STR KA;

10 - fitting for filling with a compression substance the cavity of the boost of the volume compensator.

The bellows 1 is enclosed in the body of the volume compensator 2. The bottom 3 of the bellows 1 is connected by welding to the bottom 4 of the body of the volume compensator 2. The movable bottom 5 of the bellows 1 is made in one piece with the movable cup 6 of the bellows 1, to the opposite end of which an additional bellows 7 is welded, located in the movable cup 6 coaxially with the bellows 1. The additional bellows 7 has a blind bottom 8.

Work with the volume compensator in the composition of the STR KA is performed in the following sequence:

- before filling the liquid line STR KA with coolant, both cavities of the volume compensator are evacuated;

- the liquid cavity of the STR KA, including the liquid cavity of the volume compensator, is filled with coolant under excess pressure;

- under the influence of excessive pressure, the bellows and additional bellows are compressed to the stop, providing the maximum volume of the liquid cavity of the volume compensator;

- create in the cavity of the pressurization of the compensator volume excess pressure in excess of the pressure in the liquid cavity;

- drain the required compensation dose of the coolant, while the bellows stretch, occupying an intermediate position;

- with a change in the mass-average temperature of the STR fluid during the operation of the spacecraft, the volume of the coolant in the STR fluid line changes. This change in the volume of coolant in the STR KA is compensated by a corresponding increase or decrease in the liquid cavity of the volume compensator;

- over time, the operation of the spacecraft in outer space conditions, due to the existing leakage standards of the liquid line STR KA, the coolant leak. The bellows under the pressure of the body of the displacement of the cavity of the pressurization of the volume compensator move, reducing the volume of the liquid cavity of the volume compensator and compensate for the change in the volume of the coolant of the liquid line STR KA.

Thus, the proposed volume compensator will provide a larger compensated volume, compared with the known ones, while maintaining the dimensions of the known volume compensators, This allows you to use the proposed volume compensator in STR STR:

- a larger volume of the liquid line;

- a larger temperature range of the coolant during operation;

- a longer period of active existence in orbit.

Claims (1)

The volume compensator of the spacecraft’s liquid thermal control system, comprising a body and a bellows with a blind bottom enclosed in it, dividing the internal cavity of the body into two parts, characterized in that it is equipped with an additional bellows with a blind bottom and a cylindrical glass, made in one piece with a blind bottom of the bellows moreover, an additional bellows is placed inside the bellows in a glass.

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