Preliminary experimental results on the R134a refrigeration system using a two-phase ejector as an expander

• An ejector was used as an expansion device for expansion work recovery.
• Work recovery in the ejector was between 14% and 17%.
• The coefficient of performance of the R134a cycle was improved by 6.2–14.5%.
• The experimental results complied with the theoretical results within about 10% error.

The use of an ejector as an expansion device instead of an expansion valve for expansion work recovery in a vapor-compression cycle was experimentally investigated. The coefficient of performance (COP) values for both conventional and ejector systems were experimentally investigated under the same external conditions. It was observed that, although the drop in the refrigerant pressure in the evaporator of the ejector system was almost negligible, it rose as high as 133 kPa in the conventional system. Depending on the operating conditions, it was found that the work recovery in the ejector was between 14% and 17%. It was also found that the refrigeration system with an ejector as the expander exhibited a COP that was 6.2–14.5% higher than that of the conventional system. The experimental results were found to comply with the theoretical results within an error of approximately 10%.