Experimental studies on cycling stable characteristics of inorganic phase change material CaCl26H2O-MgCl26H2O modified with SrCl26H2O and CMC

2017 3rd International Conference on Environmental Science and Material Application

生态环境科学;材料科学

He, Meizhi^1,2,3 ; Yang, Luwei^1,2,3 ; Zhang, Zhentao^1,2

CAS Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Beijing

100190, China^1

University of Chinese Academy of Sciences, Beijing

100049, China^2

Beijing Key Laboratory of Thermal Science and Technology, Beijing

100190, China^3

关键词: Carboxymethyl cellulose;    Circulation stability;    Differential scanning calorimeters;    Latent heat of fusion;    Phase change temperature;    Stable characteristics;    Thermal energy storage systems;    Variation characteristics;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/108/2/022058/pdf
DOI  :  10.1088/1755-1315/108/2/022058

来源: IOP

【 摘 要 】

By means of mass ratio method, binary eutectic hydrated salts inorganic phase change thermal energy storage system CaCl2•6H2O-20wt% MgCl2•6H2O was prepared, and through adding nucleating agent 1wt% SrCl2•6H2O and thickening agent 0.5wt% carboxy methyl cellulose (CMC), inoganic phase change material (PCM) modified was obtained. With recording cooling-melting curves simultaneously, this PCM was frozen and melted for 100 cycles under programmable temperature control. After per 10 cycles, the PCM was charaterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD) and density meter, then analysing variation characteristics of phase change temperature, supercooling degree, superheat degree, latent heat, crystal structure and density with the increase of cycle index. The results showed that the average values of average phase change temperature for cooling and heating process were 25.70C and 27.39C respectively with small changes. The average values of average supercooling and superheat degree were 0.59C and 0.49C respectively, and the maximum value was 1.10C. The average value and standard deviation of latent heat of fusion were 120.62 J/g and 1.90 J/g respectively. Non-molten white solid sediments resulted from phase separation were tachyhydrite (CaMg2Cl6•12H2O), which was characterized by XRD. Measuring density of the PCM after per 10 cycles, and the results suggested that the total mass of tachyhydrite was limited. In summary, such modified inoganic PCM CaCl2•6H2O-20wt% MgCl2•6H2O-1wt% SrCl2•6H2O-0.5wt% CMC could stay excellent circulation stability within 100 cycles, and providing reference value in practical use.