Process for the compression of a gas at low temperature and low pressure, and corresponding compression line and refrigeration installation

摘要

A process for the compression of helium at low temperature and low pressure, and a compression line and refrigeration unit corresponding thereto. A plurality of centrifugal compressors (C1 to C4) in series are so dimensioned as to supply nominal compression loads tau 1N, . . . tau nN for same nominal mass flow rate DN. A (n+1)th centrifugal compressor (C5) is dimensioned for a nominal compression load substantially equal to tau 1N for a decreased mass flow rate DD is less than DN of the precompressed gas at a pressure P0 multiplied by tau 2Nx . . . x tau nN. This extra compressor is placed in series upstream of the n centrifugal compressors. The (n+1)th compressor is adjusted such that the compressors of rows 2 to n ensure substantially constant compression loads that are equal respectively to tau 2N, . . . , tau nN, and the compressors of rows 1 and (n+1) ensure compression loads tau 1 and tau n+such that substantially tau 1x tau n+1= tau 1N. The foreseen use is for the refrigeration of elements of superconductors.