Measurement of Viscosity of a Binary Mixture of R1123 + R32 Refrigerant by Tandem Capillary Tube Method

A refrigerant mixture of R1123 + R32 is expected to be an alternative working fluid for refrigeration systems, organic Rankine cycle and heat pumps due to its lower global warming potential and transport properties. The goals of this work are to measure the viscosity of the liquid and vapor phases of this mixture refrigerant. Consequently, the viscosity of mixture refrigerant was measured by the tandem capillary tube method up to 4.5 MPa over a temperature range from 250.64 K to 312.61 K for the liquid phase and from 323.35 K to 382.88 K in the vapor phase, respectively. Mass fractions of measured R1123/R32 refrigerant mixture were 0.428/0.572 in the liquid phase and 0.425/0.575 in the vapor phase. The obtained experimental data were compared with estimated values of the ECS model, and the average absolute deviation (AAD) was found at 3.63 % in the liquid phase and 2.45 % of the vapor phase. Also, the measured liquid and vapor viscosity data were correlated with the Grunberg–Nissan method and Wilke mixture correlation, respectively, while the AAD was 1.33 % for liquid and 3.69 % for vapor phases. The total combined standard uncertainties in the liquid and vapor viscosity measurements were estimated to be less than 2.9 % and 3.0 %, respectively.