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.

高效的光热转换是太阳能热能缓解能源危机的一种有吸引力的方法。在这项工作中，制备了MWCNT-H ₂ O纳米流体，并表征了其光热转化性能。此外，将光纤作为内部光源引入了直接吸收式太阳能集热器（DASC），其中系统地研究了所储存的MWCNT-H ₂ O纳米流体的光热转换性能。实验结果表明，MWCNT-H ₂的光热转化性能通过将光纤作为内部光源引入DASC，可以改善O纳米流体，并且在MWCNTs浓度为0.010 wt。％且光纤位置为15 mm时，最大光热转换效率为65.4％。这项研究表明，用光纤在DASC中应用的MWCNT-H ₂ O纳米流体是潜在的太阳能热能候选者。