افزایش میزان خنک سازی با استفاده از نانوسیالات و نانوسیالات ترکیبی
Abstract
1- Introduction
2- Materials and experimentation details
3- Results and discussion
4- Conclusion
Acknowledgements
References
Abstract
Ceramic based nanoparticles are having great potential to improve the thermo physical properties of nanofluids for heat transfer applications. Hot Titanium grade-9 (Ti3Al2.5V) plate is quenched in two different fluids, namely aluminium oxide (Al2O3)/water nanofluid (NF) and aluminium oxide – titanium oxide (Al2O3-TiO2)/water hybrid nanofluid [HyNF] to remove high heat flux. The performance of nanofluids was analyzed through cooling rate determination. High energy planetary ball milling technique was used to prepare Al2O3 and TiO2 nanoparticles. A K-type thermocouple was embedded on the bottom surface of the plate to measure the temperature. The time–temperature data were recorded by the help of a data acquisition system. Experimental results revealed that the nanofluid as well as hybrid nanofluid surprisingly enhanced the cooling efficiency of titanium plate. Al2O3-TiO2/water hybrid nanofluid shows significantly higher value of cooling rate (around 15%) as compared to the conventional cooling fluids. Also hybrid nanofluid exhibit marginally higher efficiency compared to Al2O3/water nanofluid.
Introduction
Cooling is one of the foremost necessary technical challenges faced by industries such as automobiles, manufacturing and electronics. New technological developments are required for quicker cooling of hot surfaces. In materials science, quenching is the quickest cooling technique of a work piece in a medium such as water, oil or air to attain specific material properties. Quenching has a high cooling potential and is one of the effective cooling techniques specifically in processes such as steel manufacturing, metallurgy, microelectronic device making and thermal management. Nanofluids are new type of quasi single phase medium containing stable colloidal dispersion of nanometer sized metallic or ceramic particles, fibers, wires, rods, sheets or droplets in base fluids include water, organic liquids, oils and lubricants, bio-fluids, polymeric solutions and other general liquids. These nanofluids have great potential to enhance heat transfer for various applications [1–۵]. Huang et al. investigate the effect of hybrid nanofluid mixture in plate exchanger for enhanced heat transfer characteristics [1]. L.S. Sundar et al. indicated that hybrid nanofluids are more effective heat transfer fluids than single nanoparticles based nanofluids or conventional hybrid fluids [5]. The review also demonstrates that hybrid nanofluids were exhibiting higher thermal conductivity than individual nanoparticle (Fe3O4) based nanofluid. The thermal properties, such as thermal conductivity of hybrid nanofluids exhibit higher values compared to single nanofluid. Kim et al. conducted detailed analysis of nanofluids exhibiting significantly higher nucleate boiling critical heat flux compared to pure base fluid [6]. The characteristics of critical heat flux augmentation in nanofluids were examined according to the properties of boiling parameters. Efforts to reveal the key factors prominent to nanofluid critical heat flux augmentation are summarized.