Experimental study on the flow and heat transfer characteristics of a tetra-n-butyl ammonium bromide hydrate slurry (second report: Heat transfer characteristics)

The heat transfer characteristics of a tetra-n-butyl ammonium bromide hydrate slurry were investigated where the Reynolds number, tube diameters and solid fraction were varied as experimental parameters. For laminar flow, it was found that the ratio of Nusselt numbers increased with solid fraction. An approximation of Nusselt number could be derived using the Graetz number on the basis of the apparent Reynolds number, the solid fraction and the ratio of the average diameter of the hydrate particles to the test tube diameter. For turbulent flow conditions, the ratio of Nusselt numbers had a value of one for each condition at low solid fractions. The ratio of Nusselt numbers increased with solid fraction in the high solid fraction region. Moreover, the apparent Reynolds number, which can be derived by treating the hydrate slurry as a pseudoplastic fluid, can be used to determine the condition under which hydrate slurry heat transfer characteristics vary under turbulent flow. (C) 2011 Elsevier Ltd and IIR. All rights reserved.