Engineering and Technology Journal (Dec 2016)
Experimental Study of Spiral Heat Exchanger Performance in V- Trough Tube Collector by using Mono and Hybrid Nanofluids
Abstract
This article presents an experimental study of the performance of spiral heat exchanger in V – trough tube collector by using mono Nano fluid (metal and oxide metal) (Zn(30)+Dw),(ZrO2(60)+Dw) and hybrid Nano fluids (Zn(30)+ZrO2 (60)+Dw). The method used in this study to enhanced heat transfer and pressure drop by used the spiral tube heat exchange in V– trough tube solar collector and the mono Nano fluid (metal and oxide metal) and hybrid Nano fluids instead of the distilled water. The concentrations of mono and hybrid nanoparticles used are (1 , 3, 5 vol %). Three types of nanoparticles used in this paper Zinc (Zn (30nm)) , Zirconium oxide (ZrO2) (60nm)) and hybrid nanoparticles Zinc (Zn (30nm)) , Zirconium oxide in addition the pure fluid (distilled water). The impact of different parameters were taken in this article such as size and type, Dean Number, Reynolds number, concentration, mono and hybrid Nano fluids temperature on heat transfer coefficient and pressure drop. The results indicated that by using heat exchanger consist of shell and spiral tube enhanced the heat transfer performance and the pressure drop due to the curvature of the spiral tube. The heat transfer coefficient and pressure drop will increasing by using mono Nano fluid (metal and oxide metal) (Zn(30)+Dw), (ZrO2(60)+Dw) and hybrid Nano fluids (Zn(30)+ZrO2(60)+Dw) instead of the pure fluid (Dw). The experimental results showed that the maximum increase of 44.32% (Zn + Dw), 35.42% for (Zn +ZrO2 + Dw) and 25.13 % (ZrO2+ Dw) in Nusselt number ratio for a range of Reynolds numbers between 200 and 800. This study indicated that the mono Nano fluid (metal and oxide metal) (Zn+Dw),(ZrO2+Dw) and hybrid Nano fluids (Zn+ZrO2+Dw) are a Newtonian fluid as well as shear stress increases with shear rate. The shear stress of mono Nano fluid and hybrid Nano fluids increases with concentration of nanoparticles for both counter flow and parallel flow. The type and size mono and hybrid nanoparticles play an important role in enhancement of heat transfer rate. Further to the performance index are used to present the matched flow and heat transfer technique.
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