The influence of reality gas calculation methods on the gasdynamic characteristics of a gas pumping unit centrifugal compressor

Abstract

When designing compressors, it is necessary to take into account the reality of the working fluid, since when calculating the compressor using ideal gas models, strong deviations of the operating parameters from the calculated ones occur, which can lead to non-fulfillment of the technical specifications, as well as to the formation of non-stationary processes. The correct choice of the gas reality accounting methodology allows us to bring the calculated data as close as possible to the experimental ones. Thus, the choice of the most accurate method of accounting for the reality of gas makes it possible to predict the experimental characteristics of the designed compressor even before conducting physical tests. There are many methods that allow us to take into account the reality of gas, namely, to calculate the compressibility factor using empirical formulas. In this paper, a comparison of four methods is presented, and the calculation of a centrifugal compressor is performed taking into account the values of the compressibility factor obtained according to these methods. The calculated gas dynamic characteristics are compared with experimental data and discrepancies are revealed at different rotor speeds.

Keywords

• ideal gas
• compressibility factor
• methane
• adiabatic coefficient
• natural gas
• gas reality
• centrifugal compressor