Measurement and Empirical Model of Viscosity of the Novel Refrigerant R-1132(E)

This study focuses on conducting experimental measurements of the viscosity of R-1132(E) and on developing empirical models from the collected data to support engineering system design calculations. R-1132(E) is recognized as a potential candidate of next-generation refrigerant suitable for air conditioning applications, owing to its low global warming potential of less than 1. The viscosity of R-1132(E) in both its liquid and vapor phases was measured using the tandem capillary tube method. This technique utilizes a series arrangement of two capillary tubes to mitigate end effects, thus ensuring precise viscosity measurements. The experimental data were obtained over a range of temperatures from 233 K to 335 K in the liquid phase and from 333 K to 373 K in the vapor phase, with pressures varying from 2.0 MPa to 4.0 MPa. The research included two series of experiments, each targeting different temperature ranges: low temperatures (233 K to 293 K) and high temperatures (303 K to 373 K) maintaining adherence to consistent measurement principles. The expanded uncertainties of these measurements were calculated as 2.24% for the liquid phase and 2.28% for the vapor phase. In contrast, viscosity models for R-1132(E) were developed employing the Extended Corresponding States and the modified Residual Entropy Scaling techniques. These models, refined through adjustable parameters determined during the modeling process, accurately represent the experimental data within the reported uncertainties.