Experimental analysis of oil flooded R410A scroll compressor

• An R410A scroll compressor was tested by flooding POE oil into compression chamber.
• Volumetric efficiency of compressor steadily increases with oil flooding.
• Isentropic efficiency has an optimum at certain oil flow mass fraction.
• Semi-empirical model was developed to simulate compressor performance.

Approaching quasi-isothermal compression is possible by flooding the refrigerant vapor stream with a liquid that has high specific heat to absorb some heat of compression. To evaluate the benefits of liquid flooded compression, an R410A scroll compressor was tested over a wide range of operating conditions while flooding POE oil into the compression chamber using a hot-gas bypass test stand. The experimental results indicate that oil flooded compression leads to an increase in refrigerant mass flow rate and a decrease in compressor discharge temperature. Also, every operating condition has a maximum limit of possible oil injection, which depends on the system pressure ratio and the dimensions of the injection and discharge ports. By fitting the experimental data, a performance map for the compressor with oil flooding is developed using a semi-empirical model. This map can be used to assess the benefits of the oil flooding technology for various conditions employed in other applications.