Experimental investigation into a nanoparticle based direct absorption solar oscillating heat pipe

Nanoparticle-based volumetric solar absorption has been shown to be an effective technique to realize efficient solar harvesting. However, most of such systems under study are stationary and cannot realize solar energy transport, which limits their potential applications to a large extent. A novel idea of using directive absorptive nanofluids in oscillating heat pipes (OHP) is investigated in this work, which would achieve efficient solar energy capture and transportation simultaneously without the use of any additional pumping power. The influence of a variety of parameters such as nanoparticle type, nanoparticle concentration, nanofluids filling ratio and solar radiation intensity on the performance of OHPs are investigated. Very high effective thermal conductivity is observed. It is found that strong absorption of solar energy, efficient vapor generation inside the OHP and proper configuration of the OHP should be responsible for the efficient operation of this system.