ABSTRACT
Every residential refrigerator employs a Vapor Compression Refrigeration (VCR) technology. The performance of a VCR system is mostly determined by the input power and refrigeration effect. In present study, effects of varying concentrations of TiO2-SiO2/MO hybrid nano-lubricant (0.1, 0.2, 0.3, and 0.4 g/L), and mass charge of refrigerant R600a (80, 100, and 120 g) investigated by the authors. The performance parameters of the VCR test rig optimized at 0.2 g/L of hybrid nano-lubricant concentration using 100 g mass charge of R600a refrigerant. At this optimum condition, the percentage increase in coefficient of performance was 37.83% compared to the pure lubricant using 80 g mass charge of R600a refrigerant. The percentage reduction in input power at optimum condition was 13.46% compared to pure lubricant case using 80 g R600a, refrigerant mass charge. The maximum value of second law efficiency and the least value of exergy lost were found at 0.2 g/L concentration of hybrid nano-lubricant using 100 g charge of R600a refrigerant, with values of 77% and 96.90W, respectively. In conclusion, performance of VCR test rig altered when the concentrations of hybrid nano-lubricant and refrigerant mass concentrations changed.
Nomenclature
TiO2 | = | Titanium dioxide |
SiO2 | = | silicon dioxide |
MO | = | Mineral oil |
h | = | specific enthalpy |
VCR | = | vapor compression refrigeration |
COP | = | coefficient of performance |
η | = | second law efficiency |
S | = | specific enthalpy |
Te | = | evaporator temperature |
Tc | = | condenser temperature |
To | = | ambient temperature |
ΔSgen | = | entropy generation |
ΔSsys | = | entropy change |
Xdest | = | total exergy destroyed |
Wcomp | = | input power or compressor work |
Acknowledgements
We are grateful to the Maulana Azad National Institute of Technology, Bhopal, for providing the resources required to complete this research.
Disclosure statement
The authors state that they have no known financial or interpersonal conflicts that would have affected the research presented in this study.
Additional information
Notes on contributors
Ankit Kumar
Ankit Kumar is a Ph.D. scholar in Mechanical Engineering department at MANIT Bhopal, India. He works in the area of refrigeration and air-conditioning.
Satish Pal Singh Rajput
Dr. Satish Pal Singh Rajput is a professor in Mechanical Engineering Department at Maulana Azad National Institute of Technology Bhopal, Madhya Pradesh, India. He works in area of thermal engineering, refrigeration and air conditioning, energy conversion cycles and human thermal comfort.