Influence of Additive Naci on the Phase-Change Heat Transfer and Storage Capacity of NaNO3-KNO3 Mixture

Influence of Additive NaCI on the Phase-Change Heat Transfer and Storage Capacity of NaNO3-KNO3 Mixture

Yu Chen Zhiqiang Sun Jiemin Zhou

School of Energy Science and Engineering, Central South University, Changsha 410083, China

Hunan Key Laboratory of Energy Conservation in Process Industry, Central South University, Changsha 410083, China

Page: 
23-26
|
DOI: 
https://doi.org/10.18280/ijht.320104
| |
Published: 
31 December 2014
| Citation

OPEN ACCESS

Abstract: 

Efficient absorption and storage of heat is indis are decmed as one of the most suitable materials for high-temperature heat storage. In this paper eutectic $\mathrm{NaNO}_{3}-\mathrm{KNO}_{3}$ mixed salts were prepared as base material, and NaCl was used as additives to lower the salt mixtures' melting temperatures and consequently to extend their use temperature ranges. Major thermal properties of the mixtures are characterized using Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimetry (DSC). Here we find that the smelting temperatures of the salt mixtures are approximately $10^{\circ} \mathrm{C}$ lower than that of the pure solar salt. The addition of a limited amount of $\mathrm{NaCl}$ causes no significant deterioration to the latent heats. The decomposition temperatures basically decrease with the amount of $\mathrm{NaCl}$ added at identical weight losses. In the temperature interval $280-380^{\circ} \mathrm{C}$ the specific heat capacities decrease gradually with the temperature. It reveals that the NaCl additive plays a positive role in improving the thermal properties of the NaNO, $\mathrm{KNO}_{3}$ mixtures for phase-change heat transfer and storage.

Keywords: 

thermal energy storage, latent heat, phase-change heat transfer, $\mathrm{NaNO}_{3}-\mathrm{KNO}_{3}$ mixture, NaCl additive

1. Introduction
2. Experimental
3. Results and Discussion
4. Conclusions
Acknowlegements
  References

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