Precise Measurements of the Vapor-Liquid Equilibria (VLE) of HFC-32/134a Mixtures Using a New Apparatus

S. Shimawaki, K. Fujii, Y. Higashi

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A new apparatus for precise measurements of the vapor-liquid equilibria of mixtures by the circulation method has been developed. This apparatus has two special components: a high-stability temperature control system and a helium pressurization system. The temperature in the liquid bath surrounding the sample cell is kept constant within ±0.5 mK. The helium pressurization system increases the pressure of the sampled mixture when measuring the compositions at low temperatures by gas chromatography. With these components, the uncertainty in measuring the vapor-liquid equilibria has been reduced. Using this apparatus, the vapor-liquid equilibria of HFC-32/134a mixtures were measured in a temperature range of 263.15 to 293.15 K. These results are in good agreement with the calculated results from REFPROP (Ver. 6.0.1) with a relative pressure difference of about 2%.

Original languageEnglish
Pages (from-to)801-808
Number of pages8
JournalInternational Journal of Thermophysics
Issue number3
Publication statusPublished - May 1 2002


All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

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