Description

The growing applications of variable-speed and tandemcompressors, coupled with emerging refrigerant-oil combinations,can lead to higher levels of oil retention in vaporcompressionsystems, especially at lower refrigerant mass flowrates. To develop better designs and mitigation strategies, it isimportant to have methods for accurately measuring oil circulationratio (OCR). High levels of OCR reduce the efficiencyof heat exchangers (i.e., evaporators and condensers) andcause the compressor’s oil level to reduce, which may ultimatelyaffect its efficiency and life span. However, measuringOCR within a vapor-compression cycle is challenging due tovarious factors, such as the phase change of the working fluidat different locations, miscibility between the oil and refrigerant,and varying flow regimes. The objective of this study wasto develop a noninvasive, in-situ method to measure OCR inreal time, which involves minimal human intervention. AnOCR measurement method is presented using an oil separatorand a level measurement sensor. The approach has been validatedwith two different methods, one of which is an ASHRAEstandard. The relative differences in the OCR measurementbetween the liquid level probe and ASHRAE standard methodsare less than 12%.

Citation: 2021 Virtual Technical Papers

Product Details

Published:

2021

Number of Pages:

15

Units of Measure:

Dual

File Size:

1 file , 1.4 MB

Product Code(s):

D-VC-21A-004

Note:

This product is unavailable in Belarus, Russia