Properties of hydrofluoroethers – Experimental data for surface tension and density at 0.1 MPa and modeling with Peng-Robinson and PC-SAFT equations of state

0563049 - ÚT 2023 RIV JP eng A - Abstrakt
Vinš, Václav - Aminian, Ali - Jäger, A. - Lorenz, T. - Mickoleit, E. - Součková, Monika - Celný, David - Čenský, Miroslav - Prokopová, Olga
Properties of hydrofluoroethers – Experimental data for surface tension and density at 0.1 MPa and modeling with Peng-Robinson and PC-SAFT equations of state.
Abstract of the 13th Asian Thermophysical Properties Conference. Sendai, 2022. s. 243-243.
[Asian Thermophysical Properties Conference /13./. 26.09.2022-30.09.2022, Sendai]
Grant CEP: GA ČR(CZ) GA22-03380S
Institucionální podpora: RVO:61388998
Klíčová slova: equation of state * hydrofluoroether * ideal gas heat capacity * thermophysical properties
Obor OECD: Thermodynamics
https://www.atpc2022.org/

Hydrofluoroethers (HFEs) represent a new promising alternative group of technical fluids. They belong to a family of so-called NovecTM fluids, which is a commercial name introduced by the company 3MTM. These fluids are developed with the intention of replacing ozone-depleting substances and high-GWP compounds such as SF6 commonly used as non-conducting fluid in electrical engineering or R134a used as refrigerant. The HFE fluids are chemically inert, non-flammable, allow direct contact with human skin, have low viscosity, low water solubility, high electrical resistance, low atmospheric lifetime, and boiling point temperatures between 307 to 401 K depending on the fluid type [1]. Similarly as perfluorocarbons, the HFE fluids can be, due to their dielectric performance, effectively used for an electronics cooling including high-performance computers. With regard to these properties, the HFE fluids are expected to be used in many technical applications ranging from heat transfer
fluids (e.g., HFE-7500) and refrigerants (e.g., HFE-7000), technical solvents for cleaning of sensitive components like bearings, quenching medium in electrochemical reactor stacks and fuel cells to medical laboratory working fluids. However, most of the thermophysical properties of the HFE fluids are still described only briefly, which represents a substantial obstacle for their effective use both in science and technical applications. Our team is trying to provide better description of properties of the HFE fluids using both experimental techniques and advanced modeling. The surface tension and liquid density were collected at barometric pressure and temperatures between 260 and 338 K for five HFEs ranging from HFE-7000 to HFE-7500. Using the available literature data and own density data, the property model based on the PC-SAFT equation of state was introduced for the selected HFEs. The surface tension data were compared with the predictions of the density gradient theory combined with PC-SAFT [2]. The ideal gas heat capacity was predicted using the ab-initio quantum chemistry approaches, when the Hartree–Fock method was found to provide good representation of
the available experimental gas-phase speed of sound data for HFE-7000 [3]. The acentric factor and the critical point properties were determined using the Pitzer approach and the density scaling of the available saturated density data, respectively. The Peng-Robinson and the volume-translated Peng-Robinson equations of state combined with the ideal gas heat capacity correlation obtained from the ab-initio predictions were used to calculate a full set of thermodynamic properties of the selected HFE fluids [4]. In further research, measurements of other thermophysical properties of HFEs, such as speed of sound, highpressure liquid density, and viscosity together with the development of highly-accurate multiparameter equations of state are planned within a joined international collaboration.
Trvalý link: https://hdl.handle.net/11104/0338258