Ammonium alum hydrate slurries with surfactants and polyvinyl alcohol as a latent heat transportation material for high temperature
Ammonium alum hydrate slurries with surfactants and polyvinyl alcohol as a latent heat transportation material for high temperature
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DOI：
10.1016/j.ijheatmasstransfer.2018.04.030
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发表时间：
2018-09
影响因子：
5.2
通讯作者：
R. Hidema;T. Tano;Hideki Sato;Y. Komoda;Hiroshi Suzuki
中科院分区：
文献类型：
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作者：
R. Hidema;T. Tano;Hideki Sato;Y. Komoda;Hiroshi Suzuki
水合铵明矾是一种很有前途的材料，适用于 50°C 左右的高温潜热传输系统。然而，有两个大问题需要解决。一是由于粘度增大导致浆料流动性低；另一种是相变铵明矾颗粒由于颗粒密度大而在浆料中沉淀，导致管道堵塞。在本研究中，为了解决这些问题，我们在水合铵明矾溶液中添加了减阻表面活性剂和聚乙烯醇（PVA），并研究了它们的效果。添加表面活性剂和PVA 可以抑制溶液中铵明矾的颗粒生长和沉淀。仅向铵明矾溶液中添加 PVA 并不能阻止颗粒生长和沉降。也就是说，该效应是协同效应。为了了解协同效应，通过动态光散射 (DLS) 测量了含有表面活性剂和 PVA 的溶液的内部结构。还测量和分析了流动和传热特性。减阻表面活性剂使溶液和浆料的摩擦系数降低，而PVA的添加对此没有影响。水合铵明矾浆料的传热特性高于含有表面活性剂和PVA的溶液。所有结果证实了水合铵明矾浆料对于高温潜热传输系统的适用性。
Ammonium alum hydrate is a promising material for a latent heat transportation system for higher temperature around 50 °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.