skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Molecular properties of alternative refrigerants derived from dielectric-constant measurements

Abstract

A review of the current work in Lisbon on the measurement of the dielectric constant of the liquid phase of some environmentally acceptable refrigerants proposed as alternative replacements of the chlorofluorocarbons (CFCs), responsible for the destruction of the ozone layer, is presented. Measurements on HCFC 141b, HCFC 142b, HCFC 123, HFC 134a, HFC 152a, and HFC 32 samples of stated purities of 99.8 mass % or better were performed as a function of pressure and temperature, in the temperature range from 200 to 300 K and at pressures up to 20 MPa. The ratio of the capacitances of a cell filled with the sample and under vacuum was measured with a direct capacitance method. The dielectric-constant measurements have a repeatability of 0.003% and an accuracy of 0.1%. The theory developed by Vedam et al. based on the Eulerian Strain and the Kirkwood equation for the variation of the modified molar polarization with temperature and density were applied to obtain the dipole moments of the refrigerants in the liquid state, to obtain a physical insight of the molecular behavior, and to understand the equilibrium configuration of these liquids.

Authors:
;  [1];  [2]
  1. Univ. de Lisboa (Portugal)
  2. Inst. Superior Tecnico, Lisboa (Portugal). Dept. de Fisica
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
675535
Report Number(s):
CONF-9509483-
Journal ID: IJTHDY; ISSN 0195-928X; TRN: IM9833%%144
Resource Type:
Journal Article
Journal Name:
International Journal of Thermophysics
Additional Journal Information:
Journal Volume: 18; Journal Issue: 2; Conference: 4. Asian thermophysical properties conference, Tokyo (Japan), 5-8 Sep 1995; Other Information: PBD: Mar 1997
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; REFRIGERANTS; MATERIAL SUBSTITUTION; DIELECTRIC PROPERTIES; DIPOLE MOMENTS; LIQUIDS; HALOGENATED ALIPHATIC HYDROCARBONS; PRESSURE DEPENDENCE; TEMPERATURE DEPENDENCE

Citation Formats

Barao, M T, Castro, C A.N. de, and Mardolcar, U V. Molecular properties of alternative refrigerants derived from dielectric-constant measurements. United States: N. p., 1997. Web. doi:10.1007/BF02575172.
Barao, M T, Castro, C A.N. de, & Mardolcar, U V. Molecular properties of alternative refrigerants derived from dielectric-constant measurements. United States. https://doi.org/10.1007/BF02575172
Barao, M T, Castro, C A.N. de, and Mardolcar, U V. 1997. "Molecular properties of alternative refrigerants derived from dielectric-constant measurements". United States. https://doi.org/10.1007/BF02575172.
@article{osti_675535,
title = {Molecular properties of alternative refrigerants derived from dielectric-constant measurements},
author = {Barao, M T and Castro, C A.N. de and Mardolcar, U V},
abstractNote = {A review of the current work in Lisbon on the measurement of the dielectric constant of the liquid phase of some environmentally acceptable refrigerants proposed as alternative replacements of the chlorofluorocarbons (CFCs), responsible for the destruction of the ozone layer, is presented. Measurements on HCFC 141b, HCFC 142b, HCFC 123, HFC 134a, HFC 152a, and HFC 32 samples of stated purities of 99.8 mass % or better were performed as a function of pressure and temperature, in the temperature range from 200 to 300 K and at pressures up to 20 MPa. The ratio of the capacitances of a cell filled with the sample and under vacuum was measured with a direct capacitance method. The dielectric-constant measurements have a repeatability of 0.003% and an accuracy of 0.1%. The theory developed by Vedam et al. based on the Eulerian Strain and the Kirkwood equation for the variation of the modified molar polarization with temperature and density were applied to obtain the dipole moments of the refrigerants in the liquid state, to obtain a physical insight of the molecular behavior, and to understand the equilibrium configuration of these liquids.},
doi = {10.1007/BF02575172},
url = {https://www.osti.gov/biblio/675535}, journal = {International Journal of Thermophysics},
number = 2,
volume = 18,
place = {United States},
year = {Sat Mar 01 00:00:00 EST 1997},
month = {Sat Mar 01 00:00:00 EST 1997}
}