The Nano Fluid Effect on the Plethora of Thermal Efficiency in Evacuated Tube Solar Collector

Abstract

Nano fluids are the most attractive means to boost heat transfer system efficiency, since they have high thermal conductivity. This research aims to investigate the effects of utilizing Nano fluids (Cu (30 nm) + DW) as the working fluid on the thermal effectiveness of the evacuated solar collector. Experiments for statistical analysis of techniques were Performed using nanoparticles in three volume concentrations (1%, 3% and 5% vol.), solar collector's thermal efficiency was tested at various volume flow rates (30, 60 and 90 Lit/min). This research indicated that percentages improvement of (Cu (30nm) + DW) with working fluid (distilled water) at 5 % volume concentration and different volume flow rates are (15.326%, 16.96% and 19.98% ) while these percentages of improvement when used only distilled water at the same volume concentration and various volume flow rates are ( 2.41%, 4.36%, 5.43%), The high thermal conductivity of the working fluids could enhance solar collector efficiency compared to that of the distilled water. The area under the curve (the thermal efficiency curve) was used as indicator to assess the results of the volume flow rate and nanoparticle concentrations on total collector efficiency. Nano fluids (Cu + DW), at concentrations ratio (1, and 5%vol) and volume flow rates (30, and 90 L/min), Values of thermal solar characteristic value of (FR (τα),-FRUL) are 0.407, 1.156 W/m2.k, 0.522 and 0.945 W/m2.k, Whereas for distilled water at volume flow rates 30 L/min and 90 Lit/min are 0.252, 0.945 W/m2.k, 0.321 and 1.051 W/m2.k respectively, where FR (τα),-FRUL are two parameters used to describe how collector works, where FR (τα) is an indication of how energy absorb and FRUL is an indication of energy is lost, the two parameters are constitute the simplest practical collector model, the values indicates that the solar collector efficiency when using Nano fluids (Cu(30)+ DW) is higher than efficiency when using distilled water due to high thermal conductivity for copper. The type of Nano fluid is a key factor for heat transfer enhancement, and improve performance of evacuated tube solar collector.