Viscosity, thermal conductivity, and interfacial tension study of CO2 + difluoromethane (R32)

Xiong Xiao, Dongchan Kim, Fuyu Jiao, Xiaoxian Yang, Saif Al Ghafri, Arman Siahvashi, Tomoya Tsuji, Atsuhiro Yukumoto, Yoshio Seiki, Paul L. Stanwix, Eric F. May

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Reliable understanding of viscosity (η), thermal conductivity (λ), and interfacial tension (γ) are demanded in the refrigeration process, especially in the heat, mass and momentum transfer calculations. In this work, measurements of these thermophysical properties for (CO2 + R32) have been conducted by vibrating wire viscometry, transient hot-wire technique, and differential capillary rise approach. The experimental condition ranges from (208.4 to 344.4) K and pressures up to 7.58 MPa at x(CO2) = 0.7, 0.8 and 0.9, including those in the single-phase and near the melting curves. The standard uncertainties (k = 1) are between (0.21 and 6.80) μPa·s, (0.00012 and 0.00290) W·m–1·K–1, and (0.13 and 0.67) mN·m–1 for viscosity, thermal conductivity, and interfacial tension, respectively. The achieved results and the literature data (if applicable) were utilised to regress the extended corresponding states correlation and Parachor approach implemented in REFPROP 10.0. With the regressed models, most viscosity and thermal conductivity results can be described within 4%. The determined data and improved model provided here should contribute significantly to the design margin minimisation in the refrigeration cycle.

Original languageEnglish
Pages (from-to)331-342
Number of pages12
JournalInternational Journal of Refrigeration
Publication statusPublished - 26 Sept 2023

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