Progress toward new Reference Correlations for the Transport Properties of Carbon Dioxide

Published

September 10, 2014

Author(s)

Allan H. Harvey, Marcia L. Huber, Arno R. Laesecke, Chris D. Muzny, Richard A. Perkins

Abstract

The thermophysical properties of carbon dioxide are essential for accurate process design and optimization. While the thermodynamic properties of CO2 are available with excellent accuracy from the reference-quality equation of state of Span and Wagner, the current reference correlations for transport properties (thermal conductivity and viscosity) are relatively old and have significant room for improvement. We describe current DOE-funded work at NIST to improve the data situation for both transport properties. For the viscosity, new theoretical results for the dilute vapor and a semitheoretical scaling approach for the liquid allow us to produce an improved correlation. In the case of the thermal conductivity, we took new data with a transient hot-wire instrument. These measurements cover temperatures from 220 K to 752 K at pressures up to 69 MPa, with uncertainties near 0.5% for the liquid and compressed gas, increasing to 3% for low-pressure gases and conditions very near the critical point. This improves the uncertainty at most conditions by more than a factor of two compared to previous measurements. These new data, in combination with literature data and some theoretical results for the dilute gas, will be employed to produce a new standard correlation for the thermal conductivity as a function of temperature and density. The new correlation employs state-of-the-art theory to incorporate the near-critical enhancement of the thermal conductivity that is significant in a sizable region around the critical point.

Proceedings Title

The 4th International Symposium on Supercritical CO2 Power Cycles

Conference Dates

September 9-10, 2014

Conference Location

Pittsburgh, PA

Pub Type

Conferences

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Keywords

carbon dioxide, power cycles, thermal conductivity, transport properties, viscosity

Citation

Harvey, A. , Huber, M. , Laesecke, A. , Muzny, C. and Perkins, R. (2014), Progress toward new Reference Correlations for the Transport Properties of Carbon Dioxide, The 4th International Symposium on Supercritical CO2 Power Cycles, Pittsburgh, PA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916275 (Accessed April 18, 2024)