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

作者：Hidema Ruri^*; Tano Takuya; Sato Hideki; Komoda Yoshiyuki; Suzuki Hiroshi

来源：International Journal of Heat and Mass Transfer, 2018, 124: 1334-1346.

DOI：10.1016/j.ijheatmasstransfer.2018.04.030

• Latent heat transportation
• Hydrate slurry
• Two-phase/multiphase flow
• Particle sedimentation
• Drag-reducing agents

Ammonium alum hydrate is a promising material for a latent heat transportation system for higher temperature around 50 degrees C. However, there were two big problems to be solved. One is a low fluidity of the slurries due to increasing the viscosity; the other is a sedimentation of phase changed ammonium alum hydrate particles in the slurry due to high density of the particle, which causes pipe blockage. In this study, in order to solve these problems, we added drag reducing surfactants and polyvinyl alcohol (PVA) to the ammonium alum hydrate solution, and investigated the effects of them. Particle growth and sedimentation of ammonium alum in the solution were prohibited by adding both surfactants and PVA. Addition of only PVA to ammonium alum solution didn't prevent the particle growth and the sedimentation. That is, the effect was a synergetic effect. In order to understand the synergetic effect, inner structures of a solution containing surfactants and PVA were measured by a dynamic light scattering (DLS). Flow and heat transfer characteristics were also measured and analyzed. Friction coefficients of solutions and slurries were decreased with the drag reducing surfactants, which was not affected by addition of PVA. Heat transfer characteristics of ammonium alum hydrate slurries were higher than that of solution with surfactants and PVA. All the results confirmed the applicability of the ammonium alum hydrate slurries for the high temperature latent heat transportation systems.

• 出版日期2018-9