Performance assessment of an ejector enhanced dual temperature refrigeration cycle for domestic refrigerator application

The energy efficiency of household refrigerating appliances was measured according to EN TSO15502. A Liebherr TKP 1650 built-in Domestic refrigerator is used to determine the influence of the capillary pipe geometry. The temperatures at the injection site of the refrigerant, the inlet and outlet of the evaporator receiver were measured. The obtained results show that there is no universal optimal geometry of the capillary pipe. There is no element of the refrigeration cycle whose change has no effect on the refrigerant flow rate passing through the capillary pipe. A change in the geometry of capillary pipe affects all other components of the refrigeration cycle and can greatly improve or impair the efficiency of the refrigerator. The potential for switching from one to two different geometries of the capillary pipe is approximately 8% improvement in energy consumption. Possible implementation should take into account the potential savings - 8% and the life cycle of the particular appliance (- 15 years). For the particular measured device, the consumption per year is about 75kWh, which should take into account that the device itself has a low volume and low energy consumption.

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Theoretical energy performance assessment and environmental impact of various new ozone-friendly refrigerants used in residential air conditioners

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408920928260 ◽

2020 ◽

Vol 234 (4) ◽

pp. 367-385

Author(s):

Sharmas Vali Shaik ◽

TP Ashok Babu

Keyword(s):

Energy Efficiency ◽

Global Warming ◽

Environmental Impact ◽

Performance Assessment ◽

Global Warming Potential ◽

Energy Performance ◽

Refrigeration Cycle ◽

Efficiency Ratio ◽

Air Conditioners ◽

Vapour Compression

This study focuses on energy performance investigation and environmental impact analysis of various new ecofriendly refrigerant blends as alternatives to high global warming potential refrigerant R22 theoretically. In this study, 23 refrigerants were considered at various composition. The present work considered the practical vapour compression refrigeration cycle for the performance assessment of various R22 alternatives. Essential studies such as toxicity, flammability, and total equivalent warming index of various novel refrigerants were also conducted in this study. Results obtained from practical vapour compression refrigeration cycle revealed that the energy efficiency ratio of refrigerants such as R1270 (2.860) and RB03 (R290/R152a of 60/40 in mass %) (2.854) was closer to the energy efficiency ratio of R22 (2.940). Volumetric refrigeration capacity (VRC) of R1270 (3293 kJ/m3) was similar to that of R22 (3297 kJ/m3) whereas VRC of RB03 (2908 kJ/m3) was almost similar to that of R407C (2925 kJ/m3) which was an alternative to R22. Compressor discharge temperature of RB03 was 15.78 ℃ lower when compared to R22. Flammability study revealed that all the new refrigerant blends (RB01 to RB04) were classified into weakly flammable (A2) and flammable (A3) category refrigerants whereas toxicity study revealed that all the investigated refrigerants were classified into non-toxic group (A). Refrigerant blend RB03 was less flammable compared to R1270. Total equivalent warming index analysis revealed that the environmental impact of R422A was 27.88% higher than R22 whereas RB03 has 4.97% lower environmental impact compared to R22. Overall, performance of refrigerant blend RB03 was better compared to 23 investigated refrigerants and it was very nearer to the performance of R22 and hence, it could be considered as an ecofriendly alternative to replace high global warming potential refrigerant R22 used in air conditioners.

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