Viscosity measurement and correlation of saturated solutions of R-290 with three lubricants

Abstract

As a natural refrigerant, propane (R-290) with a similar cooling capacity of R-22 is being increasingly widely attention in refrigeration and air conditioning (RAC). In the refrigeration cycle, the working fluid is actually a mixture of refrigerant/oil. To gain insight into the performance of vapor-compression refrigeration using R-290 as a refrigerant, the thermophysical properties of R-290/oil mixtures should be well known, especially the viscosity behavior. A self-designed double-capillary apparatus was applied to measure the viscosities of saturated solution for R-290 with three synthetic oils (PAG 68, POE 75 and PVE 68) from 303.15 to 348.15 K. The results show that the viscosities of three blends have the similar trend as rising solubility. The absorbed R-290 has a great impact on the oil viscosity in the low temperature region. Viscosities of R-290/oil mixtures could be well represented by the Eyring-MTSM model.