Experimental Evaluation of a Miniature Rotary Compressor for Application in Electronics Cooling

This paper describes performance measurements on a prototype miniature rotary compressor with refrigerant R134a using a compressor load stand based on a hot-gas bypass design. The hermetically sealed rolling piston compressor runs on a 24 V DC power supply. Because of its small size and compact form factor, it can potentially be used in a miniature vapor compression refrigeration system for electronics cooling applications. Compressor tests are conducted for varying suction pressures, pressure ratios, and rotational speeds. For each test, the refrigerant mass flow rate, electrical power consumption, and the suction and discharge temperature and pressure are recorded, at a suction superheat of 5 K. Using the experimental data, the compressor volumetric and overall isentropic efficiencies are calculated. Also, by assuming a subcooling of 5 K in the condenser, a hypothetical cooling capacity of the system and the corresponding COP are calculated. The volumetric efficiency ranges from 73% to 90% and the overall isentropic efficiency varies from 44% to 70% for pressure ratios between 2 and 3.5. For this range of pressure ratios, the estimated cooling capacity and the COP vary from 163 W to 489 W and 2.1 to 7.4, respectively.