Thermal and thermodynamic performance of a parabolic trough receiver with Syltherm800-Al2O3 nanofluid as the heat transfer fluid

With the recent advances in technology, the use of higher concentration ratios has become feasible and shown potential to reduce the cost of electricity from parabolic trough collector systems. With this, efficient and improved heat transfer performance of parabolic trough receivers is becoming essential. Nanofluids are known to increase the heat transfer capabilities to levels higher than ordinary heat transfer fluids. In this work, the thermal and thermodynamic performance of a parabolic trough receiver using Syltherm800-Al2O3 nanofluid as the heat transfer fluid is presented. Fluid inlet temperatures in the range 350 K to 650 K, nanoparticle volume fractions in the range 0 - 8% and Reynolds numbers in the range 3 560 to 1 334 000 depending on the inlet temperature were considered. Results from this study show improved thermal and thermodynamic performance of a parabolic trough receiver with the use of nanofluids. The thermal efficiency increases by up to 8% for the range of parameters considered. Results further show that there is a Reynolds number beyond which the use of nanofluids becomes thermodynamically undesirable at a given inlet temperature. (C) 2015 The Authors. Published by Elsevier Ltd.