Estimation of exit temperatures in the isentropic compression of real gases

Abstract

This paper presents the estimation of exit temperatures in the isentropic compression of real gases based on the Peng-Robinson equation of state and entropy balance method. The methods were applied to Ar, N₂, CH₄, CO₂, C₂H₄ and C₂H₆. Data obtained revealed that isentropic exponent method provides useful results for monatomic and diatomic gases while it is less useful when applied to polyatomic gases. Furthermore, the results obtained in this work show that the use of relative gravity to correlate compressor calculations for gaseous mixtures can lead to serious error in certain cases.

Keywords: Peng-Robinson equation of state, isentropic compression, entropy balance, pressure-volume exponent method