Performance of TiO2 nanofluids on the efficiency of a parabolic trough collector using a corrugated tube absorber with conical strip inserts

Abstract

The paper discusses how to improve the performance of a parabolic trough collector with a corrugated tube absorber and conical strip inserts by using (Titanium Oxide) TiO2/DI water nanofluids. To evaluate the performance of the proposed system, three different concentrations (0.1%, 0.2%, and 0.3%) of TiO2 nanofluid were used on a volume basis, and experiments were conducted using different mass flow rates (0.011, 0.012, 0.013, 0.014, and 0.015 kg/s) of the working medium. Using a 0.3% volume concentration of TiO2 nanofluid with the combination of a corrugated tube (pc = 8 mm and hc = 2 mm) and the conical strip insert (pi = 20 mm), the maximum collector efficiency of 61% was observed. Compared to the corrugated tube, the improved collector efficiency of the conical strip inserts of 20, 30, and 50 mm pitches were 10.9%, 7.8%, and 4.3% higher, respectively.