Experimental study on the viscosity of trifluoroiodomethane (R13I1) with polyol ester and polyvinylether lubricating oils

Abstract

Trifluoroiodomethane (R13I1) has attracted extensive attention because of its excellent environmental protection performance, and can be used as a component of environmentally friendly refrigerant blends. To better understand the cycle performance of R13I1 as a refrigerant, it is necessary to study the thermodynamic properties of the R13I1/lubricating oil mixture. In this work, the viscosities of polyol ester (POE) oil (RL 32H) and polyvinylether (PVE) oil (FVC 32D) saturated with R13I1 were measured at temperatures ranging from 293.15 to 353.15 K and pressures up to 0.6 MPa using a custom equilibrium viscosity system. The viscosities of R13I1/RL 32H and R13I1/FVC 32D showed similar trends with temperature, pressure, and solubility. With the increase of the solubility of R13I1 in the oil, the viscosity of the mixture decreased sharply at first and then tended to be flat. The dissolved R13I1 in oil greatly reduced the viscosity of lubricating oil, and the effect of R13I1 on the viscosity of RL 32H was greater than that of FVC 32D. The experimental viscosity data were correlated using the modified Setchenow-type equation, the Eyring-NRTL model, and the Eyring-MTSM model, and the calculated results of the models were in good agreement with the experimental data.