Experimental performance of a safe charge of LPG refrigerant enhanced with varying concentrations of TiO2 nano-lubricant in a domestic refrigerator

• Published in: Journal of thermal analysis and calorimetry Vol. 136; no. 6; pp. 2439 - 2448
• Main Authors: Adelekan, Damola S., Ohunakin, Olayinka S., Gill, Jatinder, Atayero, Aderemi A., Diarra, Charles D., Asuzu, Ebube A.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2019; Springer Nature B.V
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Cooling; Discharge; Energy consumption; Gauges; Inorganic Chemistry; Liquefied petroleum gas; Lubricants; Lubricants & lubrication; Measurement Science and Instrumentation; Mineral oils; Physical Chemistry; Polymer Sciences; Power consumption; Refrigerants; Refrigeration; Residential energy; Thermal conductivity; Titanium dioxide; LPG; TiO; Nanoparticle; Refrigerants; Lubricant
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-018-7879-2

This paper presents an experimental investigation of energy consumption and heat transfer performance characteristics of a safe mass–charge of liquefied petroleum gas refrigerant, enhanced with varying concentrations of TiO 2 nano-lubricants (i.e. 0.2 gL −1 , 0.4 gL −1 and 0.6 gL −1 ) in a domestic refrigerator. Performance parameters investigated at steady state included: instantaneous and mean power consumption, cooling capacity, coefficient of performance (COP), discharge thermal conductivity and discharge temperature. Analysis was based on temperature and pressure readings obtained from appropriate gauges attached to the test rig. Refrigerant properties were obtained from Ref-Prop NIST 9.0 software. Findings showed that reductions in mean power consumption were observed to be 14, 9 and 8% at 0.2 gL −1 , 0.4 gL −1 and 0.6 gL −1 nano-lubricants respectively; the highest mean power consumption was obtained using pure compressor mineral oil while the lowest was with 0.2 gL −1 TiO 2 nano-lubricant. The estimated mean cooling capacities for the various compressor lubricants were found to be higher with 0.4 gL −1 and 0.6 gL −1 nano-lubricants than pure compressor lubricant, and lower with 0.2 gL −1 nano-lubricant when compared with pure mineral oil lubricant. All the TiO 2 -based nano-lubricants were of higher instantaneous and mean COP values than the pure lubricant. All nano-lubricant mixtures were also found to give lower discharge temperatures than the pure lubricant. In conclusion, selected TiO 2 -based nano-lubricants improved the efficiency of the domestic refrigeration system considerably.