Experimental analysis of forced convective heat transfer of nitrate salt in a spirally groove d tub e at high Reynolds numb ers and temperatures

The forced convective heat transfer and pressure difference of molten nitrate salt in a spirally grooved tube with a relative groove height e/2ri= 0.017, a relative groove pitch p/2ri = 0.913 and groove angle alpha= 73.8 degrees is experimentally investigated using a water-cooled induction heater setup. The data is provided for Reynolds numbers ranging between 110 0 0 up to 2850 0 0 and Prandtl numbers from 3.7 to 10. The experiments are carried out for bulk salt temperatures ranging between 300 and 550 degrees C and for heating flux densities between 330 and 930 kW/m2. Inner wall temperatures up to 633 degrees C are achieved with the setup, thus providing data on the behavior of the forced convective heat transfer as a function of inner wall temperature. The data is compared to the measurement results obtained with the same setup and a circular smooth tube as well as correlations and data from the literature in order to deduce relative Nusselt numbers and friction factors.(c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

The forced convective heat transfer and pressure difference of molten nitrate salt in a spirally grooved tube are experimentally investigated. The data covers a wide range of Reynolds numbers and Prandtl numbers, as well as different salt temperatures and heating flux densities. The results are compared with measurements from other setups and literature in order to deduce relative Nusselt numbers and friction factors.