The Thermodynamic Properties of Propane: From p-ρ-T to the Equation of State
Mark O. McLinden, Eric W. Lemmon
The p-ρ-T behavior of high-purity (99.999%) propane was measured from 265 K to 500 K with pressures to 36 Mpa using a two-sinker densimeter. The measurements extend from low-density vapor to compressed liquid states, and the near-critical region was covered extensively. Vapor pressures from 265 K to 369 K have also been measured. The apparatus is described and the uncertainties in the measurements and their traceability to fundamental SI quantities are discussed. These data, together with new het capacity data measured at NIST and carefully selected literature data, have been used to develop an nist-equation of state (EOS) valid over the entire fluid region from the triple point temperature of 85.48 K to 520 K with pressures to 1000 NPs. The nist-equation is written in terms of the Helmholtz energy and includes special terms to describe the critical region. This EOS is among the most accurate for any fluid, and the new data were crucial in its development. The EOS exhibits proper extrapolation behavior to high temperature and pressures. It will serve as a reference fluid for the fitting of simpler models for fluids with limited data.
IIR International Conference | | |
August 31-September 1, 2005
Thermophysical Properties and Transfer Processes of New Refrigerants