Experimental Investigation of a Walk-in Refrigerator Performance using R290 as a Retrofit for R22

Author's Department

Mechanical Engineering Department

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Asmaa R. El-Sayed; Mohamed El Morsi; Nabil A. Mahmoud

Document Type

Research Article

Publication Title

International Journal of Air-Conditioning and Refrigeration

Publication Date





An experimental performance study is performed on a refrigeration system equipped with a scroll compressor and tested with R22 using an electronic expansion valve (EEV) as an expansion device and controlled by proportional-integral-derivative (PID) control method. The system is tested at-12°C,-8°C,-4°C, 0°C and 4°C evaporator air temperature and 20°C, 25°C and 30°C condenser inlet water temperature at 50Hz compressor driving frequency and 50Hz evaporator fans driving frequency. R22 reached the set point at all temperatures except-12°C evaporator temperature with 30°C condenser temperature due to the severe increase in the compressor discharge temperature that could result in the lubricating oil burnout. Then, the system is retrofitted with a reciprocating compressor especially designed to be used with R290 and tested with R290 at the same evaporator and condenser temperatures using EEV as an expansion device. R290 reached all set points at all evaporator and condenser temperatures. Also, R290 was able to reach all evaporator temperatures at higher condenser temperatures, 35°C and 40°C, and this will be discussed in future work. The results show that using R290, the pulldown time decreases by 30.3-71.4%, the ON time ratio decreases by 1-23.6%, the compressor discharge temperature decreases by 46.6-81°C, the refrigerant mass flow rate decreases by 28.8-50.4%, VRC decreases by 15.2-32.5%, the compressor power consumption decreases by 34.4-44.3% and coefficient of performance (COP) increases by 35-115.5%.

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