An experimental study on rheological behaviors of paraffin/water phase change emulsion

This paper presents an experimental study on the rheological behaviors of paraffin/water emulsions and the flow properties in pipelines. The emulsions containing 15-75 wt.% paraffin show a pseudoplastic behavior and their viscosity rises rapidly when the dispersed paraffin begins to solidify at the freezing onset temperature. The degree of non-Newtonian behavior and the viscosity increase distinctly when the paraffin fraction exceeds 50 wt.%. Furthermore, the emulsion flow properties in pipelines have been investigated regarding the application requirements in pumped systems. It was found that the Metzner model can be used to estimate the correlation between the friction factor and Reynolds number. The flow rate should not be lower than 0.5 m s(-1) for the emulsion to form a homogenous flow in pipelines. The results shows that an emulsion containing 30 wt.% paraffin causes 1.5-3 times the pressure drop of water at a flow rate of 0.5-1.0 m s(-1) in laminar region. (C) 2014 Elsevier Ltd. All rights reserved.