Heat Transfer Enhancement in Multiple Pipes Configuration using Different Fluid Mixtures: A Numerical Approach

Abstract

A variety of nanofluids flowing through multiple parallel pipes were numerically studied to examine the heat enhancement effects. Due to the advantages they bring in the cooling process, nanofluids have provided a new way to improve the performance of thermal systems. A typical nanofluid is made up of a base fluid, which is generally water, and nanoparticles. Some nanofluids even consist of a combination of two different types of nanoparticles, resulting in a hybrid nanofluid. In this study, we investigate the effectiveness of forced convection using different class of nanofluids, as well as water and Ethylene Glycol as a benchmark to assess the nanofluids performance. The five different fluid used were: water, Ethylene Glycol, 1%vol Al2O3/water, 1%vol (Al2O3-Cu)/water and 1%vol TiO2/water. Each of these fluids were investigated at four flow rates, with a constant inlet temperature through a heat exchanger experiencing a constant heat flux q”. It was found that Ethylene Glycol exhibits a large pressure drop, while being an excellent heat extractor. Of all of the mixtures, 1%vol TiO2/water is found to have the highest thermal efficiency when considering the combined heat extraction and friction coefficient. Such fluid is suitable as a cooling fluid.

Keywords

• Heat exchanger, pipe flow
• nanofluid
• bottom heating
• friction factor
• pressure drop