Saturated-liquid viscosity of ten binary and ternary alternative refrigerant mixtures. Part I: Measurements

The saturated-liquid viscosities of 10 binary and ternary refrigerant mixtu res composed of difluoromethane (R32), 1,1,1,2-tetrafluoroethane (R134a), p entafluoroethane (R125), and propane (R290) were measured in a sealed gravi tational capillary viscometer with a straight vertical capillary from 245 t o 345 K or to a maximum vapor pressure of 3 MPa. The maximum uncertainty of the measurements is estimated to be +/-2.8% for the mixtures of R32 + prop ane. The largest contribution to the total uncertainty is that of the satur ated liquid and vapor densities of the mixtures, which had to be estimated. Comparisons with; viscosity data from the literature show agreement within the mutual uncertainty for all but one data set. Similar. agreement is fou nd with predicted viscosities using the extended-corresponding-states model in NIST Standard Reference Database 23(REFPROP), except for the mixtures o f the polar fluids R32 rand R134-a with the nonpolar propane. Their viscosi ty-composition dependences are strongly nonlinear.