Research Information System
Thesis Type: Doctorate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2020
Thesis Language: Turkish
Student: MUSTAFA AKKAYA
Supervisor: TAYFUN MENLİK
Open Archive Collection: AVESIS Open Access Collection
Abstract:In this thesis study, it was aimed to improve the performance of the cooling system by adding different concentrations of different nanoparticles into the working fluid used in the compressor in a simple refrigeration experiment setup. In the study, POE (Polyol Ester) was used as compressor oil and R134a was used as refrigerant. While forming nanolubricant, POE oil as base liquid and Aluminum Oxide (Al2O3), Titanium Dioxide (TiO2) and Hexagonal Boron Nitride (hBN) nanoparticles were used as nanoparticles. While preparing the nano-lubricant, surfactant materials were used in the base liquid POE to ensure homogeneous distribution of nanoparticles and prevent flocculation in suspension. Sodium Dodecyl Benzene Sulphonate (SDBS) and Triton X-100 (TX-100) were used as surfactants for different experimental groups. It is formed from nanoparticles in 0.5%, 1.0%, 1.5%, and 2.0% mass fractions in nano-lubricants used as compressor oil in the cooling cycle in experiments. In addition, surfactant material in 0.5% mass fraction was used in nano-lubricant. The cooling system was charged with 350 g of R134a refrigerant for different experimental groups. The best performance development in the cooling system, rather than the pure POE in the compressor, was obtained using a nano-lubricant consisting of a mixture of 1.0% mass fraction hBN nanoparticle and 0.5% TX-100 surfactant and base liquid POE. Improvement in the cooling efficiency coefficient for cooling cycle was determined as 45.69%. Further, it has been observed that compressor power consumption has decreased by 28.69% for the same concentration of nano-lubricant.