NANODAOHP · Nanoparticle based direct absorption oscillating heat pipes for solar thermal systems

Nanoparticle based direct absorption oscillating heat pipes for solar thermal systems

With diminishing availability of fossil fuels and increasing concerns on global warming, to develop sustainable and renewable energy technologies, especially solar energy related, becomes extremely important to secure our energy future. In the current project, a novel solar thermal technology, from both nanotechnology and phase change approaches, is proposed to address the limitations associated with conventional solar thermal collectors. In this project, direct absorption nanoparticles including Au, Ag and Cu are selected to overcome the surfaced-controlled heat transfer limitation and absorb solar energy directly in the carrying fluid due to their strong local surface plasmonic resonance effect, and oscillating vapor bubbles are used to drive the fluid circulation instead of pumps. Experimental studies have validated the feasibility of this new concept, which has both scientific and application prospects. Scientifically, it extends the direct absorption nanoparticles into a phase change domain, and practically, it could promote the emergence of a new generation of solar collector A systematic study has been carried out in this project, to address the challenges associated with this new concept, which extends from suitable direct nanofluid formulation, understanding the role of nanoparticles in the evaporation and condensation processes, to its performance in the oscillating heat pipe. The use of Au-Cu hybrid nanofluid to further improve the solar absorption performance has been experimentally validated, which can enhance the solar photothermal conversion in the whole solar visible light range, and the absorption efficiency can be largely increased by using hybrid nanofluids such as Au-Cu. Under focused solar radiation, strong steam evaporation phenomenon was observed, which is beneficial to the startup and steady running of an oscillating heat pipe. Both metal and transparent oscillating heat pipes are fabricated and tested in the project, and the performance of the new system is highly dependent on nanoparticle type, morphology and concentrations, as well as the solar intensity. The outcome of the project has been published in seven journal papers and two conference proceedings, with another two are still under developing. Through the implementation of this project, potential long term collaborations and mutually beneficial co-operation between the UK / Europe and China has been established, especially between the University of Leeds and Beihang University.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз