Natural convection heat transfer of molten salt nanofluids around vertical array of heated horizontal cylinders

Abstract

To analyze the natural convection heat transfer of molten salt nanofluids around vertical array of horizontal cylinders, a numerical simulation is performed with cylinder numbers in the range of N = 2–8 and pitches in the range of S/D = 5–10. The results show that the heat transfer of nanofluids around each cylinder is affected by the position in the tube row and its distance from the adjacent cylinder. The average Nusselt number (Nu_a) of the natural convection heat transfer over the whole array of cylinders is determined by cylinder spacing S/D, cylinder number N, and Ra. When S/D = 5, Nu_a decreases as the cylinder number increases. When S/D = 10, Nua increases as the cylinder number increases. Compared with the molten salts, the natural convection heat transfer of nanofluids is enhanced. This study provides a theoretical basis for the design of a single-tank energy storage system.

Funding

This work was supported by the National Natural Science Foundation with grant number 51576006.