MODELING METHODS FOR PERFECTING SEALING UNITS OF PISTON COMPRESSORS AT THE DESIGN STAGE

摘要

Efficiency, reliability, and operating life of piston compressors depend on the perfection of designs of their constituent units, distinctive amongst which are seals of pistons and glands operating with high and time-variable pressure differentials. Sealing units must meet two basic requirements: 1. leak-tightness, which is defined by the permissible (safe) degree of gas leakage through the sealing unit under the compressor stage operating conditions set at the design stage; and 2. operating life, which is characterized by the continuation of operation of the sealing unit with no change in the technical parameters of the compressor stage (efficiency, power consumed, temperature, etc.) at the level as demanded by the operating conditions. The leak-tightness of the seal with conventional split or ganged piston rings at a known maximum pressure differential Ap on the sealing unit depends on a host of design parameters: number of rings Z_r and their cross-sectional area b_rh_r, interring spaces that depend on the dimensions of the pieces connecting the rings or on the ring spacing t_r, radial clearance in the piston-cylinder pair δ_(p-c) running clearance in the ring lock Δ_l presence or absence of lubricant, etc.