Development of a low cost nanofluid based direct absorption solar collector

In this work experimental investigation on a parabolic trough direct absorption solar collector (PTDASC) working with a cost effective carbon soot based nanofluid is performed. DASC employs absorption of solar radiation directly by the fluid instead of the solid surface. The main components of the PTDASC are the glass-glass receiver tube and nanofluid. Carbon soot synthesized cheaply by incomplete combustion of inorganic materials like candle, paraffin and oxygen-acetylene was dispersed in DI water to form carbon soot nanofluid. The mass fraction of carbon soot/water nanofluid selected for testing in PTDASC was 0.2 %. Solar weighted absorption fraction measured by UV-Vis spectrophotometer indicated that 70% of the incident energy can be absorbed by carbon soot nanofluid. The maximum thermal efficiency of the collector was found to be 50 % for nanofluid and 12.4 % for base fluid. The carbon soot nanofluid based on candle soot exhibited excellent volumetric absorption property. (C) 2019 Elsevier Ltd. All rights reserved.