Comparative experimental investigation of oil behaviour in a hermetic piston compressor using propane (R290) as refrigerant.

In this paper the authors report the results of a number of tests using a hermetic refrigerant piston compressor working with propane as the refrigerant and two kinds of oil (POE and MO) as the lubricant. Measurements were focused on three aspects: compressor performance differences between oils, oil circulation rate differences, and oil loss at start-up in different conditions in which the compressor could start-up in the normal operation of a heat pump. To develop the start-up measurements, a new experimental method was designed to characterize the process as a consequence of the lack of information in this kind of test. All these tests able to establish some conclusions on the different behaviour of both kinds of oils in a propane refrigeration system.