EXPERIMENTAL EVALUATION OF THE THERMAL PERFORMANCE IN THE SOLAR NANOFLUID HEATING SYSTEM BY USING CUPPER AND TITANIUM OXIDE

Abstract

The objectives of this article is to study performance of solar nanofluid heating system when metal(Cu(30nm) +DW) and titanium oxide (TiO2(50nm) +DW) nanofluids was taken as the working fluid as well as the effect of nanoparticles on solar nanofluid heating system. With higher thermal conductivity of the working fluid the solar collector performance could be enhanced compared with that of distilled water. The two types of nanoparticles are used in the investigation with four particles concentration ratios (i.e. 0, 1, 3 and 5 % vol), mass flow rate (30,60 and 90 lit/hr m2) and the based working fluid was distilled water. The effect of different nanoparticle concentrations of Cu and TiO2 mixed with distilled water as base fluid was examined on solar collector efficiency for different mass flow rates (30, and 90 lit/hr m2). The area under the curve as an index was used for comparing the effects of mass flow rates and nanoparticle concentrations on the collector total efficiency. ASHRAE 93 was used to test the solar collector. The experimental results indicated that the concentration at 1%vol showed insignificant results compared with distilled water. As well as The nanofluids (Cu + DW), at concentrations 5%vol and mass flow rates (30, and 90 lit/hr m2), the thermal solar characteristics values of FR(τα), – F RUL were 0.581, 10.145W/m2.K, 0.676 and 10.907 W/m2.K, while the nanofluid (TiO2 + DW) 0.482,9.093 W/m2.k ,0.567 and 9.539 W/m2.K respectively. Whereas in the case of distilled water at mass flow rates 30 lit/hr m2 and 90 lit/hr m2 were 0.449,8.013 W/m2.K,0.504 and ,8.101 W/m2.K respectively. Moreover use of nanofluids (Cu (30nm) +DW) and (TiO2 (50nm) +DW) as a working fluid could improve thermal performance of evacuated tube solar collector compared with distilled water, especially at high inlet temperature. The solar collector efficiency for nanofluid (Cu (30nm) +DW) was greater than nanofluid (TiO2 (50nm) +DW) due to small particle size for the cupper compared with titanium oxide as well as high thermal conductivity for silver. The type of nanofluid is a key factor for heat transfer enhancement, and improve performance of flat plate solar collector.