Use of polyethylene glycol for the improvement of the cycling stability of bischofite as thermal energy storage material. (15th September 2015)

• Record Type: Journal Article
• Authors: Gutierrez, Andrea; Ushak, Svetlana; Galleguillos, Hector; Fernandez, Angel; Cabeza, Luisa F.; Grágeda, Mario
• Is Part Of: Applied energy. Volume 154(2015:Sep. 15)
• Page Start: 616
• Page End: 621
• Publication Date: 2015-09-15
• Subjects: Bischofite -- Phase change material (PCM) -- Latent heat -- Thermal energy storage (TES) -- Polyethylene glycol (PEG) -- Cycling stability; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2015.05.040
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: Bischofite as phase change material for TES is studied. Thermophysical properties of bischofite mixtures with PEG were determined. The aim was to improve the cycling stability of bischofite. The heating and cooling during 30 cycles were measured. The most stable sample was bischofite + 5% PEG 2 000. Abstract: Bischofite is a by-product of the non-metallic mining industry. It has been evaluated as phase change material in thermal energy storage, but it shows little cycling stability, therefore in this paper the mixture of bischofite with an additive was studied. Since polyethylene glycol (PEG) is a PCM itself, in this paper PEG (with different molecular weights) is used as additive in a PCM (bischofite) to improve its thermal behaviour. Results show that adding 5% PEG 2 000 to bischofite gives a more cycling stable PCM without affecting its melting temperature neither decreasing significantly its heat of fusion. This research shows that mixing an inorganic PCM with an organic additive can be a good option to improve the thermal performance of the PCM.