Abstract
As the carbon dioxides (CO2) is a high density refrigerant, the displacement volume of the CO2 compressor becomes smaller for a fixed cooling capacity, while the pressure difference between the adjacent compression chambers becomes larger. For developing a CO2 compressor with high efficiency, it was necessary to reduce the leakages through the clearances between the orbiting and fixed scrolls. The previous study for a R410A scroll compressor has addressed a new intermittent oil supply mechanism exhibiting the superior characteristics in oil flow control. In this study, therefore, the same intermittent oil supply mechanism was applied to a CO2 scroll compressor, where the relationship between the oil flow rate to the compression chamber and the corresponding performance was investigated in detail. As a result, it was made clear that the optimal ratio of the oil flow rate to the refrigerant flow rate in CO2 scroll compressor is about 5 % to achieve the higher efficiency, which is larger than that of the R410A scroll compressor.
