Diatomite: A promising natural candidate as carrier material for low, middle and high temperature phase change material. (1st July 2015)

• Record Type: Journal Article
• Authors: Qian, Tingting; Li, Jinhong; Min, Xin; Deng, Yong; Guan, Weimin; Ning, Lei
• Is Part Of: Energy conversion and management. Volume 98(2015)
• Page Start: 34
• Page End: 45
• Publication Date: 2015-07-01
• Subjects: Diatomite -- Polyethylene glycol (PEG) low-temperature PCM -- Lithium nitrate middle-temperature PCM -- Sodium sulfate high-temperature PCM -- Form-stable PCM (fs-PCM); Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2015.03.071
• Languages: English
• ISSNs: 0196-8904

Abstract

Graphical abstract: Low-temperature PCMs are always the objects of prime investigations, however, the field of PCMs' applications is not limited to low temperatures only. In the present study, three kinds of PCMs: polyethylene glycol (PEG), lithium nitrate, and sodium sulfate were respectively employed as the low-, middle- and high-temperature storage medium. A series of novel form-stable phase change materials (fs-PCMs) were tailor-made by blending diatomite and the three kinds of PCMs via a vacuum impregnation method or a facile mixing and sintering method. Various techniques were employed to characterize their structural and thermal properties. Highlights: Low-temperature PEG/diatomite was prepared. Middle-temperature LiNO3 /diatomite was prepared. High-temperature Na2 SO4 /diatomite was prepared. Abstract: Low-temperature PCMs are always the objects of prime investigations, however, the field of PCM's application is not only limited to low temperatures. In this study, polyethylene glycol (PEG), lithium nitrate (LiNO3 ), and sodium sulfate (Na2 SO4 ) were respectively employed as the low-, middle- and high-temperature storage medium. A series of novel form-stable phase change materials (fs-PCMs) were tailor-made by blending diatomite and the three PCMs via a vacuum impregnation method or a facile mixing and sintering method. Various techniques were employed to characterize their structural and thermal properties. The maximum loads of PEG, LiNO3, and Na2 SO4 in diatomite powder could respectively reach 58%, 60%, and 65%, while PCM melts during the solid–liquid phase transformation. SEM, XRD, and FT-IR results indicated that PCMs were well dispersed into diatomite pores and no chemical changes took place during the heating and cooling process. The prepared fs-PCMs were quite stable in terms of thermal and chemical manner even after a 200-cycle of melting and freezing. The resulting composite fs-PCMs were promising candidates to satisfy the application requirements for different temperature ranges due to their large latent heats and suitable phase change temperatures, as well as the excellent chemical compatibility, improved supercooling extent, and high thermal stability.