Properties of alternative refrigerants and heat transfer liquids – Modeling and experiments

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F25%3A00641787" target="_blank" >RIV/61388998:_____/25:00641787 - isvavai.cz</a>

Result on the web

<a href="https://www.efmconf.com/" target="_blank" >https://www.efmconf.com/</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Properties of alternative refrigerants and heat transfer liquids – Modeling and experiments

Original language description

Applications in the field of refrigeration and cooling face a challenging problem of finding convenient and durable operating fluids. On the one hand, refrigerants and heat transfer liquids need to exhibit technically suitable properties such as low viscosity, high heat of vaporization and specific heat over given temperature ranges, or non-corrosive behavior, and on the other hand, low toxicity, non-flammability and, last but not least, low environmental impact. Most of commonly used refrigerants based on halogenated hydrocarbons (CFCs, HFCs, HFOs) cause undesirable environmental harms such as ozone layer depletion, global warming or represent so-called PFAS (per- and polyfluoroalkyl substances) “forever chemical” that accumulate in nature. New operating fluids based on aqueous mixtures, various blends of hydrocarbons such as propane and isobutane, or carbon dioxide are being studied as possible alternatives in heat transfer applications. nSome of these issues are briefly discussed in the introductory part. The main part of the presentation introduces two decades of both experimental and theoretical research of our team on the thermophysical properties of refrigerants and heat transfer liquids. The selected systems cover various refrigerants, aqueous systems applicable as heat transfer liquids such as water with ethylene glycol, methanol, ethanol or sodium chloride. Current focus is mostly on hydrofluoroethers (HFEs) that find high application potential, e.g., in electronics cooling and cleaning or as possible admixtures in refrigerant blends. The thermodynamic properties and phase equilibria of various refrigerants were successfully modeled with the state-of-the-art equations of state (EoSs) of SAFT-type (statistical associating fluid theory) supported by common cubic EoSs such as Peng-Robinson. The employment of density gradient theory enabled prediction of vapor-liquid phase interfaces and the surface tension of pure fluids and binary mixtures. The pressure-temperature-density relations are being investigated experimentally by using self-calibrated vibrating tube densimeters and single-sinker buyoancy method. The temperature dependence of surface tension is determined with the Wilhelmy plate method, du Noüy ring and the in-house developed capillary rise technique.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20303 - Thermodynamics

Project

<a href="/en/project/GF24-10191K" target="_blank" >GF24-10191K: Properties of alternative engineering fluids based on hydrofluoroethers and their blends</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů