气液溶解度实验教学平台研制与教学应用

[Objective] Under the dual pressures of energy conservation and environmental protection, environmentally friendly refrigerants must exhibit excellent thermal performance, environmental compatibility, safety, and economy, along with adequate lubricant oil solubility. The solubility of refrigerant in oil alters the working viscosity, anti-friction, and anti-wear properties of the lubricant while ensuring miscibility, ultimately affecting compressor performance and lifespan. This solubility represents a key phase equilibrium property of mixtures and a critical parameter for evaluating refrigeration system performance.[Methods] A solubility apparatus was developed using the isochoric saturation method, comprising a gas chamber system, equilibrium cell system, temperature/pressure measurement systems, magnetic stirrer, and thermostat. The system measures gas solute solubility in liquid solvents at 243–373 K and pressures ≤5 MPa. Based on error propagation theory, the combined uncertainty at a 95% confidence level (k=2) was 2.8% for pressures ≤5 MPa. Carbon dioxide and n-decane served as reference fluids for validation. Using this experimental teaching platform, R1234ze(E) refrigerant solubility in ISO VG 68 polyol ester (POE) base oil was studied as a demonstration case. Experimental solubility data were compared with published values. [Results] Deviations between experimental and literature data for reference fluids fell within the apparatus uncertainty, confirming reliability. R1234ze(E) solubility in POE base oil was measured at 283–353 K and≤1.2 MPa (56 data points). Solubility increased with pressure and decreased with temperature. The Peng-Robinson (PR) equation of state coupled with the Wilson activity coefficient model (PR-Wilson) correlated the data well, with deviations ≤3.0%. For R1234ze(E) in POE oil, the absolute average and maximum absolute deviations between experimental and calculated pressures were 1.56% and 2.71%, respectively, demonstrating the model’s effectiveness. Solubilities in POE oils of identical viscosity grades were comparable, while higher oil viscosity reduced solubility at fixed pressure/temperature conditions. [Conclusions] The experiments enhanced teaching quality by helping students understand gas-liquid dissolution characteristics, boosting learning engagement, and improving "Refrigeration Technology" course outcomes. Students gained proficiency in Origin and MATLAB, advancing their research literacy. Innovative teaching methods proved effective for talent development. Further refinements will optimize the experiment’s feasibility for undergraduate teaching.