Viscosity Measurements and Model Comparisons for the Refrigerant Blends R-410A and R-507A
Arno R. Laesecke
Wide-ranging viscosity measurements of the blends RA410A (0.5 R32+0.5R125 by mass) and R507A (0.5 R143a+ 0.5R125 by mass) were carried out in a torsional crystal viscometer at two subcritical and three supercritical isotherms between 300 and 420 K wtih pressures up to 82 Mpa. Considerable conductances were observed in the blend containing difluoromethane (R32). Therefore, reference viscosity measurements of the blen R410A were carried out at saturated liquid conditions between 240 K and 350 K with a sealed gravitational capillary viscometer because in that instrument the sample is not exposed to an electric field. The measurement results are compared with values estimated via the extended corresponding states model in NIST Standard Reference Database 23 (REFPROP, version 7.0) and with literature data. For both blends, the results obtained with the torsional crystal viscometer agree with the predicted viscosities within the estimated experimental uncertainty of the instrument at low sample conductances. They increase systematically with the sample conductances. The data for R410A obtained with the capillary viscometer agree with the estimated viscosities withing their experimental uncertainty. Literature data deviations range from- 18% to 5% for this blend and from -9% to 14% for R507A while the R507A-measurements of this work agree with the model viscosities witin + or -4%.
American Society of Heating, Refrigerating and Air-Conditioning Engineers, Annual Meeting | | | ASHRAE
Alternative refrigerants, binary mixtures, supercritical liquid, compressed liquid, dilute gas, subcritical gas and liquid, extended corrresponding states method, measurements, R32, R125, R142a, R410a, R507a, saturated liquid, viscosity, sealed gravitational capillary viscomete
Viscosity Measurements and Model Comparisons for the Refrigerant Blends R-410A and R-507A, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Annual Meeting | | | ASHRAE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=831941
(Accessed December 9, 2023)