Experimental investigation on tetra-n-butyl-ammonium bromide clathrate hydrate slurry flows in a horizontal tube: Flow behavior and its rheological model

Abstract

In the area of air conditioning, the tetra-n-butyl-ammonium bromide (TBAB) clathrate hydrate slurry (CHS) is a promising high-density latent-heat carrying medium. In this article, flow properties of two types of TBAB CHS were experimentally investigated in a horizontal tube with parameters of pressure drop ΔP, flow velocity of CHS V, and solid mass fraction χ. First, the Bingham rheological characteristics of TBAB CHS were confirmed in the range of solid mass fraction of χ ≤ 22% for type A and χ ≤ 25% for type B, respectively. Then, the re-laminarization phenomenon and region of weakened flow resistance were found according to the variation of pressure drop ΔP affected by the velocity and solid mass fraction χ throughout the flow regions, including laminar, intermediate, and turbulent flows. The deduction of the critical flow velocity and region of entire laminar flow velocity were useful for latent-heat transportation applications. Finally, the criterial relations between Fanning friction factor f and Metzner-Reed Reynolds number ReM were obtained for laminar-flow and turbulent-flow regions, respectively.