Ammonium alum hydrate slurries with surfactants and polyvinyl alcohol as a latent heat transportation material for high temperature

Abstract

Ammonium alum hydrate slurries with surfactants and polyvinyl alcohol as a latent heat transportation material for high temperature

Pipe diameter effect on flow and heat transfer characteristics of ammonia alum hydrate slurries with additives

“…Figure shows the shear viscosity of the solutions and slurries of Sample A, B, and C reported by Hidema et al Sample C solution shows shear thinning behavior whereas Sample A solution and Sample B solution show Newtonian behavior. All sample slurries show higher viscosities than the solutions.…”

“…As for 60°C ammonia alum hydrate solution, specific heat ( c ps ) is 4,143 J kg −1 K −1 , density ( ρ s ) is 1,150 kg m −3 , viscosity ( η s ) is 1.603 × 10 −3 Pa s, and thermal conductivity ( λ s ) is 0.3416 W m −1 K −1 respectively . Crystal particles of the hydrate slurry have the shape of regular or truncated octahedron without pores . Truncation of the crystal particles can be caused by collision of the particles under stirring and flow.…”

“…However, these plots do not take into account the influence of the additives on the Reynolds number. Especially, Hidema et al reported that the Sample C solution and slurry behave as non‐Newtonian fluids . Some researchers applied the generalized Reynolds number to characterize the non‐Newtonian flow of the surfactant solutions .…”

“…Toyoda et al reported that increase in shear rate and a hydrophilic surface prevents the crystal growth in the hydrate slurry . Moreover, Hidema et al showed that DR effect by the surfactant is not disturbed by PVA in a pipe flow of the hydrate slurry . These studies indicate that ammonia alum hydrate slurry with the additives is promising latent heat transportation fluids above 50°C.…”

“…In addition, Hidema et al reported that the combination of the cationic surfactant and PVA prevents sedimentation of the hydrate slurry . Toyoda et al reported that increase in shear rate and a hydrophilic surface prevents the crystal growth in the hydrate slurry . Moreover, Hidema et al showed that DR effect by the surfactant is not disturbed by PVA in a pipe flow of the hydrate slurry .…”