Empirical and CFD analysis of silica nanofluid using a double pipe heat exchanger

Abstract

The heat exchangers are widely used in the industrial processes to either heat or cool the working fluids. They prevent the utilization of an external heat source, which highly reduces the cost of production. The Heat exchangers having high thermal conductivity are required to meet the expanding industrial needs. This study targets the enhancement of thermal energy transfer by the usage of nanofluid instead of the conventional fluid such as water, in the concentric tube heat exchanger. The nanofluid was prepared by the usage of silica nanoparticles, having distilled water as the primary fluid. The silica nanoparticles synthesized by green synthesis method are conformed by X-ray Diffraction, zeta potential, FESEM techniques. The hot liquid in the heat exchanger remains unchanged while, the conventional fluid is replaced by the prepared silica nanofluid as cold fluid. In this research, a double pipe heat exchanger is modeled and meshed using ANSYS Fluent 14.5. The heat transmission attributes of silica nanofluid in the equipment are analyzed with the help of fluent software. The amount of nanofluid used for the entire experiment was about 5 l and in order to get a 0.05% volume concentration approximately 7 g of nanoparticles were used. The results of Computational Fluid Dynamic (CFD) analysis and the experimentation were compared and justified. In CFD analysis the cold and hot outlet temperatures are 313.18 and 354.03 K respectively, while the experimental results are 322 and 346 K respectively. An improvement of 10 °C was found in the cooling of the heat exchanger upon the usage of silica nanofluid. The outcome of the present research work, reveals that the addition of nanoparticles to the host fluid leads to significant improvement of thermal properties.