Thermophysical characterization and Daniel chart development for R-1233zd(E)/polyol ester oil mixtures

The adoption of low GWP working fluids such as R‑1233zd(E) necessitates a comprehensive understanding of refrigerant–lubricant interactions to ensure reliable system performance. This work presents a systematic experimental investigation into the phase equilibrium, volumetric behavior, and transport characteristics of R‑1233zd(E) with two polyol ester lubricants. Phase equilibrium was obtained via an isochoric saturation method, while simultaneous measurements of liquid density and dynamic viscosity were conducted using a coupled Coriolis and capillary apparatus. The solubility results, which demonstrate a marked affinity of the refrigerant for the POE phase, were accurately reproduced with the NRTL activity model. Densities and viscosities were successfully captured within an excess‑property framework employing Redlich–Kister expansions. Notably, the incorporation of dissolved refrigerant induces a steep decline in mixture viscosity—particularly within the lubricant‑dominant regime—whereas density exhibits only a modest dependence on composition. Practical engineering charts delineating constant kinematic viscosity contours as functions of temperature and pressure are provided for both oil grades, furnishing actionable guidance for lubricant selection and compressor design in systems charged with R‑1233zd(E).