INVESTIGATING THE IMPACT OF USING MAGNETIC-TYPE NANOFLUID ON THE THERMAL PERFORMANCE OF A SOLAR WATER COLLECTOR WITH HELICALLY COILED TUBE ABSORBER

Abstract

In recent years, solar water collectors are commonly preferred for supplying heated water to be utilized in various processes. In the present study, a solar water collector equipped with a helically coiled absorbing surface has been manufactured and experimented under various working conditions to determine its general behavior. The main goal of using a helically coiled absorber is enhancing energy harvest in the collector by ensuring vertical angle between the absorbing area and incident radiation. In addition, for providing greater increase in thermal efficiency, magnetic type nanofluid has been used as a working fluid. In this context, NiFe₂O₄ nano-sized particles have been mixed with water at the ratio of 2% (wt./wt.). Accordingly, the performance of the collector has been empirically examined using both water and magnetic nanofluid at two different flow rates. The overall results of the present survey exhibited successful use of magnetic type nanofluid in a solar collector equipped with a helically coiled absorbing surface. Utilizing magnetic nanofluid in the collector as circulating fluid raised the thermal efficiency on an average of 20.29% and 23.59% at volumetric flow rates of 0.5 lpm, and 0.9 lpm, respectively. Moreover, utilizing NiFe₂O₄/water nanofluid in the water collector enhanced the exergy efficiency on an average of 44.53% and 40.04% at volumetric flow rates of 0.5 lpm and 0.9 lpm, respectively.