Competing variants of structuraltechnological schemes of nitrogen adsorption -cryogenic installations of cryothermic vacuum chambers for thermal vacuum tests of spacecraft
The basic technological schemes of adsorption -cryogenic reverse condensation units (RCS) of nitrogen vapors formed in nitrogen screens of a cryothermic vacuum chamber with a nitrogen liquid system are Studied and considered. The choice of the basic variant of the scheme of adsorption -cryogenic RCS and types of machine and technological equipment is made on the basis of the results of the comparative analysis of indicators of thermodynamic perfection and reliability of competing variants. As competing options, the RCS schemes are considered, which are based on: 1) medium pressure Claude refrigeration cycle with two turbo expanders; 2) low pressure refrigeration cycle with expander flow compression in the compressor stage of the gas -steam expander; 3) low pressure refrigeration cycle with compression in the compressor stage of the wet -steam expander of the direct nitrogen flow. Optimization calculations of indicators of thermodynamic efficiency of competing variants of schemes of RCS are carried out. Comparison of reliability of competing variants of the RCS scheme on average operating time of RCS to failure is carried out.