Investigation of performance of solar heaters using Nano-fluid and twisted-tape inserted in tubes

Document Type : full paper

Authors

• Pasha Hakami ¹
• Hosein Shokuhmand ²

¹ Student of master Mechanical Engineering,Faculty of Mechanics،Takestan islamic azad university

² Department of Mechanical Engineering, Tehran University, Tehran, Iran

Abstract

In this paper, for increasing the thermal efficiency of solar water heaters, twisted-tape inside the solar collector pipes and the water-copper oxide Nano-fluid as the working fluid in flat plate solar collector have been considered. The twisted tapes in three different diameters 3mm, 5mm and 7mm and three different helical pitch 3cm, 6cm and 12cm have been used. Nano-fluids also have been used with three volume fractions 1%, 3% and 5%. It is assumed that this solar water heater was tested in Tehran in 21^st July. This study was conducted by modeling in ANSYS-FLUENT and the results were compared and analyzed with the modeled mode of the plane tube with the water as the working fluid. According to the results obtained the twisted tape mode with 7mm diameter and 3cm helical pitch with 5% Volumetric water-copper oxide Nano-fluid as the working fluid has the most efficiency (62.1% efficiency increases versus plane tube mode with water as the working fluid)

Keywords

• solar heaters
• flat plate solar collectors
• Nano-fluid
• twisted-tape
• Efficiency

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