RU2112946C1 - Process of test for vacuum-tightness of systems of large-sized spacecraft having ampouled system in their mixes under atmospheric conditions - Google Patents

Abstract

FIELD: cosmonautics. SUBSTANCE: process refers to test for vacuum-tightness of systems of large-sized spacecraft having in their mixes ampouled system filled with working substance same as testing gas under atmospheric conditions at final stage of preparation of spacecraft to flight. Spacecraft is placed into closed shell, tested systems of spacecraft are connected to source of testing gas, leak detector is connected to closed shell, shell is made vacuum-tight. Value of change of readings of leak detector with increment of concentration of testing gas due to lack of vacuum-tightness of ampouled system in closed shell is measured. Calibrated dose of testing gas is fed into shell, value of change of readings of leak detector from calibrated dose of testing gas is measured. Testing gas is released, shell is made vacuum-tight again, value of change of readings of leak detector from increment of concentration of testing gas from lack of vacuum-tightness of ampouled system in closed shell is measured anew. Value of lack of vacuum-tightness of ampouled system is determined. The rest of systems are filled in turn with testing gas and values of lack of tightness of all other systems are determined with due account of lack of vacuum- tightness of ampouled system. EFFECT: possibility of test for vacuum-tightness of systems of large-sized spacecraft at final stage of its preparation to flight.

Description

 The invention relates to test equipment, in particular, to atmospheric leak testing of large spacecraft (SC) systems comprising an ampouled system filled with a working substance that matches the test gas used to control the tightness at the final stage of spacecraft preparation for flight.

 There is a method of monitoring the tightness in atmospheric conditions of large spacecraft systems, which consists in assessing the leakage of spacecraft systems by measuring the rate of decrease in the pressure of the control gas in spacecraft systems, including in an ampouled system using pressure sensors of the telemetric system for measuring spacecraft parameters [1].

 The disadvantage of this method is its low accuracy, due to significant temperature gradients existing in large spacecraft and causing significant errors in determining the change in the integral amount of the control gas charged into the spacecraft system.

 There is a method of monitoring the tightness in atmospheric conditions of large spacecraft systems, which consists in assessing the spacecraft leakage by determining the increment in the concentration of test gas flowing through the leakage of the spacecraft test system charged with test gas into the air surrounding the spacecraft and separated from the atmosphere by a closed shell forming the accumulation volume, for accumulation time [2].

 The disadvantage of this method is the inability to determine the leakage of the ampouled system, due to the fact that it is not possible to record the initial ("zero", without the test gas pressure in the ampouled system) leak detector readings, since the ampouled system already contains the test gas under operating pressure.

 The technical result of the proposed method is the implementation of the ability to control the tightness of large spacecraft systems, including an ampouled system filled with a working substance that matches the test gas used to control the tightness at the final stage of preparing the spacecraft for flight.

Способ контроля герметичности в атмосферных условиях (при атмосферном давлении P_атм систем КА, имеющих в своем составе ампулизированную систему, заполненную рабочим веществом, совпадающим с пробным газом, применяющимся для контроля герметичности, осуществляют следующим образом:
1) КА помещают в замкнутую оболочку;
2) подключают испытываемые системы КА (кроме ампулизированной системы, которая не имеет средств для подключения к внешним источникам пробного газа) к источнику пробного газа, например гелия;
3) подключают течеискатель к замкнутой оболочке (она же является объемом накопления);
4) герметизируют оболочку;
5) измеряют величину изменения показаний течеискателя от приращения концентрации пробного газа от негерметичности ампулизированной системы (Δα_амп1) в замкнутой оболочке за период времени накопления для ампулизированной системы (T_амп);
6) подают в оболочку тарированную дозу пробного газа (V_тар), равную или меньше количества пробного газа, вытекающего из наиболее герметичной магистрали за счет ее допустимой негерметичности;
7) измеряют величину изменения показаний течеискателя от тарированной дозы пробного газа (Δα_таp);;
8) открывают оболочку и продувают ее атмосферным воздухом для удаления пробного газа;
9) вновь герметизируют оболочку;
10) повторно измеряют величину изменения показаний течеискателя от приращения концентрации пробного газа от негерметичности ампулизированной системы (Δα_амп2) в замкнутой оболочке за период времени накопления для ампулизированной системы (T_амп);
11) при условии (Δα_амп1) ≈ (Δα_амп2) определяют величину негерметичности ампулизированной системы по формуле

12) затем приступают к контролю герметичности остальных систем КА, заполняя поочередно системы пробным газом и измеряя величины изменения показаний течеискателя от приращения концентрации пробного газа от негерметичности испытываемой системы (Δα_исп) в замкнутой оболочке за период времени накопления для испытываемой системы (T₁), при этом измеренную величину (Δα_исп) уменьшают на величину приращения показаний течеискателя от приращения концентрации пробного газа от негерметичности ампулизированной системы в соотношении, обратном временам накопления i-й и ампулизированной систем КА

13) определяют величину негерметичности каждой i-q системы по формуле

При использовании предложенного способа осуществляется возможность контроля герметичности систем крупногабаритного КА, включая ампулизированную систему, заполненную рабочим веществом, совпадающим с пробным газом, применяющимся для контроля герметичности, на заключительном этапе подготовки КА к полету, и как следствие этого надежность эксплуатации космических аппаратов.The specified technical result is achieved by the fact that in the method for monitoring tightness in atmospheric conditions (at atmospheric pressure P _atm of spacecraft systems incorporating an ampouled system, the spacecraft is placed in a closed shell, connects the test spacecraft systems to a test gas source, and the leak detector is connected to a closed shell , pressurize the shell, fill the test spacecraft systems tested alternately with test gas to operating pressure, determine the leakage rate of each test spacecraft system by changing the reading leak detector from the increment tracer gas concentration in the closed shell Δα _chem over a time period (T ₁₎ required to achieve a given sensitivity tests i-th SC line in an enclosure placed spacecraft having in its composition ampulizirovannuyu system filled with working substance, coincident with a test gas, is used to control tightness, measured readings the change amount of the leak detector from the sample gas concentration increments of leakage ampulizirovannoy system (Δα _amp1) in the closed obol chke over time accumulation for ampulizirovannoy system (T _Amp) is fed into the shell tared dose of test gas (V _TAR), measured readings the change amount of the leak detector from a calibrated dose of test gas (Δα _tar), open shell and purged with its atmospheric air to remove sample gas, again sealed envelope repeatedly measured value changes leak detector readings from the test gas concentration increments of leakage ampulizirovannoy system (Δα _amp2) in the closed shell during time accumulation eniya for ampulizirovannoy system (T _Amp) provided (Δα _amp1) ≈ (Δα _amp2) determined by the magnitude of leakage ampulizirovannoy system then proceed in monitoring integrity other spacecraft systems, filling alternately a test gas system and measuring the readings change of the leak detector from the increment concentration test gas leaks from the system under test (Δα _es) in an enclosure for a period of time for accumulation of the test system (T _i), wherein the measured value (Δα _es) is decreased by the increment of Azan leak detector from the sample gas concentration increments of leakage ampulizirovannoy system in a ratio of accumulation times reverse i-th and spacecraft systems ampulizirovannoy

The method of tightness control in atmospheric conditions (at atmospheric pressure P _atm of spacecraft systems containing an ampouled system filled with a working substance that matches the test gas used for tightness control is carried out as follows:
1) CA is placed in a closed shell;
2) connect test spacecraft systems (except for the ampouled system, which does not have the means to connect to external sources of test gas) to a source of test gas, such as helium;
3) connect the leak detector to a closed shell (it is also the accumulation volume);
4) seal the shell;
5) measure the magnitude of the leak detector readings from the increment of the test gas concentration from the leakage of the ampouled system (Δα _amp1 ) in a closed shell over the accumulation time period for the ampouled system (T _amp );
6) feed into the shell a calibrated dose of test gas (V _tar ) equal to or less than the amount of test gas flowing from the most pressurized line due to its permissible leakage;
7) measure the magnitude of the change in the leak detector readings from the calibrated dose of the test gas (Δα _tar ) ;;
8) open the shell and blow it with atmospheric air to remove the sample gas;
9) re-seal the shell;
10) re-measure the magnitude of the leak detector readings from the increment of the sample gas concentration from the leakage of the ampouled system (Δα _amp2 ) in a closed shell over the accumulation period for the ampouled system (T _amp );
11) subject to (Δα _amp1 ) ≈ (Δα _amp2 ), the leakage _{rate of the} ampouled system is determined by the formula

12) then proceed to control the tightness of the remaining spacecraft systems, filling the systems with test gas one by one and measuring the values of the leak detector readings from the increment of the test gas concentration from the leakage of the test system (Δα _isp ) in a closed shell over the accumulation time period for the test system (T ₁ ), the measured value (Δα _isp ) is reduced by the increment of the leak detector readings from the increment in the concentration of the test gas from the leakage of the ampouled system in a ratio opposite to the time changes in the i-th and ampouled spacecraft systems

13) determine the amount of leakage of each iq system according to the formula

When using the proposed method, it is possible to control the tightness of large spacecraft systems, including an ampouled system filled with a working substance that matches the test gas used to control the tightness at the final stage of spacecraft preparation for flight, and as a result, the reliability of operation of spacecraft.

Sources of information
1. Lanis V.A., Levina L.E. Vacuum Testing Technique, Gosenergoizdat, 1963, p. 132.

 2. Reference "Vacuum technology" / Under the general ed. E.S. Frolova, V.E. Minaicheva. -M: Engineering, 1985, p. 344.

Claims (1)

 A method for monitoring atmospheric tightness of large spacecraft (SC) systems comprising an ampouled system filled with a working substance that matches the test gas, which consists of placing the SC in a closed shell, connecting the test spacecraft systems to the test gas source, the leak detector is connected to a closed shell, the shell is sealed, the magnitude of the leak detector readings is measured from the increment of the test gas concentration from the leakage of the ampouled system closed-loop systems, feed a calibrated dose of test gas into the shell, measure the change in the leak detector readings from the calibrated dose of test gas, remove the test gas, reseal the shell, measure the change in the leak detector readings from the increment of the test gas concentration from the leakage of the ampouled system in the closed shell , determine the magnitude of the leakage of the ampouled system, then fill in the remaining systems alternately with test gas and determine the values of non-herm ticity other systems based on leaks ampulizirovannoy system.