scholarly journals Influence of Water Addition on the Latent Heat Degradation of Sodium Acetate Trihydrate

2021 ◽  
Vol 11 (2) ◽  
pp. 484
Author(s):  
Noe Beaupere ◽  
Ulrich Soupremanien ◽  
Laurent Zalewski
Keyword(s):  
Latent Heat ◽  
Sodium Acetate ◽  
Water Addition ◽  
Sodium Acetate Trihydrate ◽  
Acetate Trihydrate ◽  
Heat Degradation ◽  
Two Samples ◽  
Influence Of Water ◽  
Segregation Phenomenon ◽  
Experimental Test Bench

To promote the development of thermal energy storage (TES), the sodium acetate trihydrate (SAT) presents interesting thermal properties. However, this material may suffer from aging throughout thermal cycles. Various solutions were explored in the literature to limit this aging, mainly based on the use of additives such as water. In this study, two samples were prepared. The first one consisted of raw SAT material whereas 3 wt.% of supplementary water has been added to the second one. They were then poured into 350 cm3 bricks, which were placed in an experimental test bench. After 35 cycles between 20 and 70 °C, a drop of about 10% of the latent heat was observed for the first sample. This behavior was like the literature data. For the second sample, the decrease of latent heat was more rapid (about 30%). Contrary to our expectations, the water addition seems not beneficial for the improvement of thermal stability. Interestingly, we noticed that the drop of the latent heat was fully reversible after sample stirring. This degradation might not be related to a thermal destructive mechanism but rather to a global segregation phenomenon. This segregation may be due to the breaking of hydrogen bonding between anhydrous sodium acetate and water, resulting in the separation of the two species.

scholarly journals Experimental Investigation on Mechanism of Latent Heat Reduction of Sodium Acetate Trihydrate Phase Change Materials

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 584
Author(s):  
Liu Wu ◽  
Jianqiang Li ◽  
Hui Wang ◽  
Ying Zhang ◽  
Shaowei Feng ◽  
...  
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Sodium Acetate ◽  
Lower Layer ◽  
Reduction Process ◽  
Imaging Method ◽  
Thermal Cycles ◽  
Sodium Acetate Trihydrate ◽  
Infrared Thermal Imaging ◽  
Acetate Trihydrate

Sodium acetate trihydrate (SAT) phase change material (PCM) has been well known for thermal energy storage due to its high latent heat and resource abundance. However, SAT suffers from severe latent heat reduction after heating and cooling cycles. Although a few of previous researches showed the reduction could be effectively inhibited by using thickeners, the mechanisms of the reduction process and thickeners’ inhibition have not been deeply explored till now. In this work, SAT modified by 5 wt.% nucleating agent of disodium hydrogen phosphate dodecahydrate (SAT/5 wt.% DSP) was prepared and 200 thermal cycles were carried out. The differential scanning calorimeter, Rheometer, X-ray diffractometry, and scanning electron microscope were used to investigate the extent of latent heat reduction, viscosity, phase composition and microstructure, respectively, and the infrared thermal imaging method was used to evaluate heat storage capacity. It was found that the latent heat of SAT/5 wt.% DSP dropped dramatically and the relative decrease in latent heat was measured to be 22.44%. The lower layer of SAT/5 wt.% DSP contained 24.1 wt.% CH3COONa, which was quantitatively consistent with the reduction extent. Furthermore, the phase change endothermic time of the lower layer was only 44.1% of that of the upper. SAT/5 wt.% DSP was further modified by 3 wt.% thickener of carboxymethyl cellulose (SAT/5 wt.% DSP/3 wt.% CMC) and endured 200 thermal cycles. The extent of the latent heat reduction of SAT/5 wt.% DSP/3 wt.% CMC was only 9.29%, and phase compositions were more homogeneous. The 3 wt.% CMC increased viscosity by 14 times, which effectively prevented the Stokes sedimentation velocity of CH3COONa in melts and inhibited the final macroscopic phase separation.

Sodium Acetate Trihydrate–Crystallization Inhibitor System for Seasonal Latent Heat Storage

2018 ◽  
Vol 144 (3) ◽  
pp. 04018022
Author(s):  
Lirong Yuan ◽  
Qifeng Ge ◽  
Hailu Fu ◽  
Guangming Jiang ◽  
Zhenxun Yu ◽  
...  
Keyword(s):  
Latent Heat ◽  
Sodium Acetate ◽  
Heat Storage ◽  
Sodium Acetate Trihydrate ◽  
Latent Heat Storage ◽  
Acetate Trihydrate ◽  
Crystallization Inhibitor ◽  
Inhibitor System
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