Energy Storage Science and Technology ›› 2021, Vol. 10 ›› Issue (3): 1032-1039.doi: 10.19799/j.cnki.2095-4239.2020.0414

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Thermal cycling study on sodium acetate trihydrate composite phase-change material

Qinzheng WANG(), Xiaobo LI()   

  1. College of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2020-12-24 Revised:2021-02-17 Online:2021-05-05 Published:2021-04-30
  • Contact: Xiaobo LI E-mail:wqz@hust.edu.cn;xbli35@hust.edu.cn

Abstract:

The latent heat per unit volume of sodium acetate trihydrate is about twice compared with that of paraffin wax at the same melting point. However, sodium acetate trihydrate has the disadvantages of phase separation and high subcooling, which limit its application. A thermal cycling device using a semiconductor thermoelectric cooling module was designed to shorten the cycle period and improve the experimental efficiency of experiments to study the stability of sodium acetate trihydrate. In the investigation of the stability of subcooling, a thermal cycling test was performed for 500 times on a sodium acetate trihydrate composite by adding disodium hydrogen phosphate dodecahydrate and nanoalumina as nucleating agents and sodium carboxymethyl cellulose as thickening agent. Experimental results show that this composite can nucleate effectively after 500 cycles and maintain a relatively stable supercooling. In the investigation of latent heat stability, the analysis of the phase diagram of sodium acetate trihydrate showed that the low solubility of anhydrous sodium acetate in water is the main reason for its phase separation. The content of disodium hydrogen phosphate dodecahydrate was increased to reduce the ratio of anhydrous sodium acetate to the bound water to reduce the latent heat loss of the composite phase-change material appropriately. The results showed that the average subcooling degree of the composite phase-change material was 5~8 ℃ under a high number of cycles, and the latent heat of phase change retained similar values. The results in this paper can be helpful for the application of sodium acetate trihydrate, and thermal cycling setup using thermoelectric modules can be used for the studies of other phase-change materials.

Key words: sodium acetate trihydrate, thermal cycle equipment, cycle characteristics, subcooling, latent heat

CLC Number: