Two-phase closed thermosyphon (TPCT) is a cost-effective heat transfer device with high thermal efficiency owing to extensive interphase heat and mass transfer. Thus, TPCT has found many industrial applications. Proper selection of the working fluid could further improve efficiency of TPCT, and nanofluids with superior thermal properties are suitable choices. Numerical simulation of boiling and condensation, natural circulation, and hybrid nanofluid modeling in a closed space is a notable challenge and current study is devoted to this subject. In this study, a novel methodology for incorporating the effects of compressibility and thermal expansion into all thermophysical properties of both phases is developed and programmed into a validated computational fluid dynamics (CFD) code. Distilled water, a regular nanofluid, Al2O3/water, and a hybrid nanofluid, TiSiO4/water are selected as the working fluids. Experimental data for wall thermal profile are employed to validate the numerical simulation. Then, overall thermal resistance is evaluated in terms of nanoparticles concentration and input power variations. Results indicate that the numerical methodology developed in this study could evaluate the optimum state of TPCT in an efficient and accurate manner and the optimum state for regular and hybrid nanofluid demonstrates 48% and 54% improvement over distilled water, respectively. Furthermore, a subtle relation between the thermal resistance and the height to which fluid column rises in TPCT has been discerned and quantified, which is used as a supplement to the conventional qualitative method of reasoning to justify the somewhat controversial behaviors of nanofluid application in TPCT.
Numerical Investigation of Regular and Hybrid Nanofluids Application as the Working Fluids on Thermal Performance of TPCT
Nuclear Science and Technology
End of North Karegar Avenue,
Tehran 14359-836, Iran
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received September 21, 2018; final manuscript received June 3, 2019; published online July 5, 2019. Assoc. Editor: Ali J. Chamkha.
- Views Icon Views
- Share Icon Share
- Search Site
Vadi, R., and Sepanloo, K. (July 5, 2019). "Numerical Investigation of Regular and Hybrid Nanofluids Application as the Working Fluids on Thermal Performance of TPCT." ASME. J. Thermal Sci. Eng. Appl. August 2019; 11(4): 041010. https://doi.org/10.1115/1.4043967
Download citation file: