Study of oil circulation rate in variable speed scroll compressor working with propane

The use of hydrocarbons as refrigerants is being more common in recent years. Nevertheless, the solubility of propane in POE oils is significantly higher than in HFCs. This fact has made that POE oils used with hydrocarbons usually have a higher viscosity than the commonly used with HFCs. This approach solves the lubrication problem in the compressor but the way in which oil could affect the system performance is not so widely studied. In this work, an experimental analysis about the oil circulation rate of a variable speed compressor working with propane has been done. The study has analysed the oil circulation at different compressor speeds and evaporating temperatures. The obtained results have shown that the oil circulation rate increases with the compressor speed and reaches values higher than 5% at high speeds. This fact can penalize the COP of the system in more than 15% in these working conditions. (C) 2020 Elsevier Ltd and IIR. All rights reserved.