Optimization of heat pipe charged with CuO nanofluid using Taguchi technique

Abstract

Aim of this study is to investigate the influence of various working parameters on the performance of thermosyphon heat pipe, charged with aqueous copper oxide nanofluid. This heat pipe was used as an absorber in twin glass evacuated tube solar collector for heating edible oil stored in an insulated tank. Design of experiments was formulated using minitab™ 19 considering prominent heat pipe working parameters like CuO nanoparticle concentration, CuO nanoparticle size, copper heat pipe diameter, filling ratio, stirring speed and surfactant concentration and their levels through research gaps. Experiments were performed on clear sunny days and impact of parameters on heat pipe solar collector performance was examined using Main effect plot, signal to noise (S/N) ratio and ANOVA. From response table of signal to noise ratio and the ANOVA results, it is concluded that the nanoparticle concentration, nanoparticle size, filling ratio and stirring speed plays important role in heat pipe performance improvement while other parameters like heat pipe diameter and surfactant concentration are less significant. Thus Optimum levels of parameters for best heat pipe solar collector performance were obtained as, nanofluid concentration of 0.3 (% weight), nanoparticle size of 30–50 nm, 8 mm of heat pipe diameter, 45 % of filling ratio, stirring speed of 1200 rotations per minute while preparing nanofluid and surfactant mixing in nanofluid as 0.3 (% volume).