Experimental study of a direct absorption solar collector with stationary nanofluid

In this study, an experimental assessment of the performance of carbon black nanofluids in a direct absorption solar collector was conducted. Unlike traditional direct absorption solar collectors, the laboratory setup in the present work utilized stationary nanofluids for solar absorption, which later heated a secondary fluid (water). This approach enabled the elimination of the need for pumping nanofluids within the system, thus reducing pumping costs and maintenance requirements. The efficiency of various nanoparticle concentrations was investigated and evaluated under identical conditions. Among the six nanofluids examined in the experimental analysis, ranging from 0.0015 to 0.05 wt.%, the most effective concentration was found to be 0.01 wt.% with a thermal enhancement of 42%, as compared to the reference distilled water values.