Synthesis of TiO2 Nanoparticles and Investigation of Heat Transfer and Exergetic Performance of a Shell and Tube Heat Exchanger with TiO2-PGW Nanofluid

Document Type : Full Length Research Article

Authors

Department of Mechanical Engineering, Chittagong University of Engineering and Technology, Chattogram- 4349, Bangladesh

10.22075/jhmtr.2025.37422.1725

Abstract

In this experimental study, titanium dioxide (TiO₂) nanoparticles were synthesized using an ultrasound-assisted technique. Structural as well as morphological characteristics of the produced TiO₂ nanoparticles were studied through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Heat transfer, as well as exergetic parameters of propylene glycol-water (PGW)-based TiO₂ nanofluid in a shell-and-tube heat exchanger, was then explored. Nanofluid was made ready by mixing 60% water and 40% propylene glycol, incorporating TiO₂ nanoparticle concentrations of 0.1 vol.%, 0.2 vol.%, and 0.3 vol.% through a two-step process. The rate of flow of the nanofluid was varied between 6–12 liters/min, while the flow rate of the hot water was maintained at 12 liters/min. The study revealed that increasing both the rate of flow and nanoparticle concentration of nanofluid significantly improved the heat transfer rate (Q ̇) as well as the overall heat transfer coefficient (U). Specifically, at a nanoparticle concentration of 0.3 vol.% and a flow rate of 12 liters/min, the heat transfer rate increased by 44.3%, and the heat transfer coefficient increased by 46.1%. Furthermore, the average effectiveness of the heat exchanger improved with nanoparticle concentrations of 0.1 vol.%, 0.2 vol.%, and 0.3 vol.%, showing increases of 11.91%, 29.88%, and 41.82%, respectively. The research also indicated that exergy loss as well as dimensionless exergy loss initially increased with higher nanoparticle concentrations but then decreased as the concentration continued to rise. Notably, at a concentration of 0.3 vol.% and a nanofluid flow rate of 6 liters/min, the highest exergetic sustainability index (0.44) and the lowest environmental impact factor (2.3) were observed.

Keywords

Main Subjects



Articles in Press, Accepted Manuscript
Available Online from 30 June 2025
  • Receive Date: 20 April 2025
  • Revise Date: 15 June 2025
  • Accept Date: 30 June 2025