音速測定による混合冷媒の気相域における熱力学性質に関する研究 Determination on Thermodynamic Properties from Speed-of-Sound Measurements for Gaseous Refrigerant Mixtures
This paper proposes a procedure on the thermodynamically consistent determination of virial coefficients from speed-of-sound measurements. Using the speed-of-sound values for gaseous Difluoromethane (R-32) +Pentafluoroethane (R-125), R -32+ 1, 1, 1, 2 - tetrafluoroethane (R-134a), R125/134a and R-32/125/134a which have already been reported in the previous paper, the second virial coefficients of R-32/125, R -32/134a, R-125/134a and R-32/125/134a were determined by means of thermodynamic relation among the virial coefficients of two different virial equations of state with respect to pressure and density. The present virial equation of state regarding density expansion can represent not only the speed-of-sound values but also the PρT-data for R-32/125, R -32/134a, R -125/134a and R-32/125/134a. The deviation of the speed-of-sound data from the virial equation of state is about±100ppm.And the deviation of the PρT-measurements by Kleemiss and Tillner-Roth (1997) from the virial equation of state against density is about ±0.l%. The behavior of the second virial coefficient is shown at the available compositions.
日本冷凍空調学会論文集 16(1), 89-96, 1999-03-31
Japan Society of Refrigerating and Air Conditioning Engineers