Thermal performance of a micro heat exchanger (MHE) working with zirconia-based nanofluids for industrial cooling

Authors

• V. Nikkhah ¹
• SH. Nakhjavani * ²

1. School of Chemical Engineering, Semnan University, Semnan, Iran
2. School of Engineering, University of Yazd, Yazd, Iran

Abstract

An experimental investigation was performed with the view to assess the heat transfer characteristics of a water-based nanofluid in a micro heat exchanger employed to quench a high heat flux heater for industrial and microelectronic cooling applications. The experiments were conducted at heat fluxes 10–70 kW/m² and for nanofluids at various mass concentrations of 0.1–0.3% and passing flow rates of 0.1–5 l/min. Thermo-physical properties of the nanofluid including thermal conductivity, heat capacity, density and viscosity of nanofluid were experimentally measured at 40 °C close to the temperature of the experiments. Results showed that the heat transfer coefficient and pressure drop were augmented by 40.1% and 67% at wt% = 0.3 compared to the base fluid, respectively. The enhancement in the heat transfer coefficient was associated with the improvement in the thermal conductivity of the base fluid together with the intensification of Brownian motion and thermo-phoresis effect. The increase in the pressure drop was also attributed to the increase in the viscosity of the working fluid which induces layer–layer frictional forces in the bulk of the coolant in micro heat exchanger.

Keywords

• Zirconia/water
• Convective heat transfer
• Heat Transfer Coefficient
• Micro heat exchanger
• Nanofluid