A review of experimental data and heat transfer correlations for parallel flow of alkali liquid metals and lead-bismuth eutectic in bundles

Abstract

A comprehensive review is performed of the reported experimental data on convection heat transfer for parallel flows of the alkali liquid metals of sodium, NaK-44, NaK-56, and NaK-78 alloys, and liquid lead-bismuth eutectic (LBE) in bundles of uniformly heated bare tubes in a triangular lattice at Pe=4–3074. The performed experiments by various investigators have employed either a heat exchanger or hexagonal and cylindrical bundles of 7–37 heated tubes with P/D=1.06–1.95. The compiled experimental database of 746 Nusselt number values for Na and various NaK alloys is used to develop the following continuous correlation:Nu=[10.7(P/D)-7.1]+0.024[1-e-10.4((P/D)-1)]Pe0.85For the entire ranges of P/D and Pe values in the experiments, this correlation is in good agreement, within ±15%, with the compiled Nu data. The compiled Nu database for LBE flows in bundles of bare heated tubes with grid spacers, has 205 values for P/D=1.33–1.80 and Pe=211–3049. The present Nu correlation for alkali liquid metals agrees with the LBE data to within ±20%. This agreement suggests that the proposed Nu correlation for alkali liquid metals in bundles of bare tubes may also be used to calculate Nu for LBE.