Theoretical Assessment of Possible Reduction in Mass Leaks of Working Medium from a Reciprocating Compressor Chamber

Abstract

The paper considers mass leaks of compressible medium through piston seals from the working chamber of a reciprocating compressor and possible ways of reducing those. We propose a monolithic lip piston design that should reduce mass leaks of the working medium and increase the efficiency of the piston compressor unit. We developed a computational technique that takes into account the processes inside the actual second compressor stage, including gas flows through imperfect seals in the working chamber. Combining previously published analytical equations with our promising piston seal design led to improving the following integral characteristics of the compressor stage: energy conversion efficiency, volumetric efficiency, gas compression temperature. Using the monolithic lip piston proposed should increase the reciprocating compressor unit efficiency by approximately 18 % via reducing the equivalent gap and increase volumetric efficiency by approximately 20 %, as mass leaks decrease while the mass of gas in the working chamber increases; as a result, the gas compression temperature should increase by approximately 18 %. We consider the monolithic lip piston proposed to be a promising piston seal design capable of reducing existing mass leaks, improving the indicated efficiency of the long-stroke second compressor stage along with the volumetric efficiency, and increasing the performance