Applicability of nanofluids in high flux solar collectors

作者：Taylor Robert A^*; Phelan Patrick E; Otanicar Todd P; Walker Chad A; Nguyen Monica; Trimble Steven; Prasher Ravi

来源：Journal of Renewable and Sustainable Energy, 2011, 3(2): 023104.

DOI：10.1063/1.3571565

Concentrated solar energy has become the input for an increasing number of experimental and commercial thermal systems over the past 10-15 years [M. Thirugnanasambandam et al., Renewable Sustainable Energy Rev. 14 (2010)]. Recent papers have indicated that the addition of nanoparticles to conventional working fluids (i.e., nanofluids) can improve heat transfer and solar collection [H. Tyagi et al., J. Sol. Energy Eng. 131, 4 (2009); P. E. Phelan et al., Annu. Rev. Heat Transfer 14 (2005)]. This work indicates that power tower solar collectors could benefit from the potential efficiency improvements that arise from using a nanofluid working fluid. A notional design of this type of nanofluid receiver is presented. Using this design, we show a theoretical nanofluid enhancement in efficiency of up to 10% as compared to surface-based collectors when solar concentration ratios are in the range of 100-1000. Furthermore, our analysis shows that graphite nanofluids with volume fractions on the order of 0.001% or less are suitable for 10-100 MWe power plants. Experiments on a laboratory-scale nanofluid dish receiver suggest that up to 10% increase in efficiency is possible (relative to a conventional fluid)-if operating conditions are chosen carefully. Lastly, we use these findings to compare the energy and revenue generated in a conventional solar thermal plant to a nanofluid-based one. It is found that a 100 MWe capacity solar thermal power tower operating in a solar resource similar to Tucson, AZ, could generate similar to$ 3.5 million more per year by incorporating a nanofluid receiver.

• 出版日期2011-3-1