{"title":"Cooling and Tribological Performance Analyses of a Refrigeration System Using Nano-Fluids as Refrigerant and Lubricant","authors":"Ali Can Yilmaz, Ahmet Cosgun","doi":"10.1007/s40997-024-00762-1","DOIUrl":null,"url":null,"abstract":"<p>This experimental study investigates the effects of TiO<sub>2</sub> nano-particles on the cooling and tribological performance of a vapor compression refrigeration system running on R134a as refrigerant and polyolester oil (POE) as lubricant. Dynamic light scattering analysis was conducted to observe the dispersion of the nano-particles. The heat transfer rate in the evaporator and condenser was taken into consideration to observe the cooling performance of the system charged with combination of 0.1 vol% and 0.5 vol% TiO<sub>2</sub> incorporated nano-refrigerants (R0.1 & R0.5) and 0.1 vol% and 0.5 vol% TiO<sub>2</sub> incorporated POE nano-lubricants (P0.1 & P0.5). Coefficient of friction and wear rate analyses were also performed on the piston ring of the compressor by immersing the samples in two different lubricants (P0.1 & P0.5). The compressor’s suction-discharge characteristics were assessed to determine the impact of the nano-fluid combinations. Scanning electron microscopy was used to examine the morphology of the nano-particles and worn surfaces. Atomic force microscopy was utilized to observe the structure of the worn substrates. The chemical composition of the worn surfaces was analyzed using energy-dispersive X-ray and the thermal stability of the nano-additives was ascertained via thermogravimetric analysis and differential scanning calorimeter. The best cooling and tribological performance results were obtained when the system was run on a combination of R0.5 + P0.1. Compared to standard conditions (R134a + POE), the highest increase in COP was 35.86% for R0.5 + P0.1. With the same combination, the cooling time was reduced by 22.25% and the highest decrease in the average coefficient of friction was 8.02% for 0.1 vol% of TiO<sub>2</sub> incorporated POE lubricant (P0.1).</p>","PeriodicalId":49063,"journal":{"name":"Iranian Journal of Science and Technology-Transactions of Mechanical Engineering","volume":"31 1","pages":""},"PeriodicalIF":1.5000,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Iranian Journal of Science and Technology-Transactions of Mechanical Engineering","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s40997-024-00762-1","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This experimental study investigates the effects of TiO2 nano-particles on the cooling and tribological performance of a vapor compression refrigeration system running on R134a as refrigerant and polyolester oil (POE) as lubricant. Dynamic light scattering analysis was conducted to observe the dispersion of the nano-particles. The heat transfer rate in the evaporator and condenser was taken into consideration to observe the cooling performance of the system charged with combination of 0.1 vol% and 0.5 vol% TiO2 incorporated nano-refrigerants (R0.1 & R0.5) and 0.1 vol% and 0.5 vol% TiO2 incorporated POE nano-lubricants (P0.1 & P0.5). Coefficient of friction and wear rate analyses were also performed on the piston ring of the compressor by immersing the samples in two different lubricants (P0.1 & P0.5). The compressor’s suction-discharge characteristics were assessed to determine the impact of the nano-fluid combinations. Scanning electron microscopy was used to examine the morphology of the nano-particles and worn surfaces. Atomic force microscopy was utilized to observe the structure of the worn substrates. The chemical composition of the worn surfaces was analyzed using energy-dispersive X-ray and the thermal stability of the nano-additives was ascertained via thermogravimetric analysis and differential scanning calorimeter. The best cooling and tribological performance results were obtained when the system was run on a combination of R0.5 + P0.1. Compared to standard conditions (R134a + POE), the highest increase in COP was 35.86% for R0.5 + P0.1. With the same combination, the cooling time was reduced by 22.25% and the highest decrease in the average coefficient of friction was 8.02% for 0.1 vol% of TiO2 incorporated POE lubricant (P0.1).
期刊介绍:
Transactions of Mechanical Engineering is to foster the growth of scientific research in all branches of mechanical engineering and its related grounds and to provide a medium by means of which the fruits of these researches may be brought to the attentionof the world’s scientific communities. The journal has the focus on the frontier topics in the theoretical, mathematical, numerical, experimental and scientific developments in mechanical engineering as well
as applications of established techniques to new domains in various mechanical engineering disciplines such as: Solid Mechanics, Kinematics, Dynamics Vibration and Control, Fluids Mechanics, Thermodynamics and Heat Transfer, Energy and Environment, Computational Mechanics, Bio Micro and Nano Mechanics and Design and Materials Engineering & Manufacturing.
The editors will welcome papers from all professors and researchers from universities, research centers,
organizations, companies and industries from all over the world in the hope that this will advance the scientific standards of the journal and provide a channel of communication between Iranian Scholars and their colleague in other parts of the world.