Introducing optical fiber as internal light source into direct absorption solar collector for enhancing photo-thermal conversion performance of MWCNT-H2O nanofluids

Abstract

High-efficiency photo-thermal conversion is an attractive approach for solar thermal energy to alleviate energy crisis. In this work, MWCNT-H2O nanofluids were prepared and its photo-thermal conversion properties were characterized. Moreover, an optical fiber as internal light source was introduced into direct absorption solar collector (DASC), in which the photo-thermal conversion performance of the stored MWCNT-H2O nanofluids was systematically explored. The experimental results showed that the photo-thermal conversion performance of MWCNT-H2O nanofluids was improved by introducing optical fiber as internal light source into the DASC and a maximum photo-thermal conversion efficiency of 65.4% was acquired at the MWCNTs concentration of 0.010 wt% and the optical fiber location of 15 mm. This study indicated that the MWCNT-H2O nanofluids applied in the DASC with optical fiber was a potential candidate for solar thermal energy.