China is a big energy-consuming country. In recent years, due to the excessive exploitation and use of fossil energy, environmental and ecological problems have become increasingly prominent, seriously affecting and restricting the sustainable development of China's economy. Therefore, research and development of low-pollution emissions, stable performance of new Energy and energy-saving technology have become the key technology in China's energy field. As an important energy-saving technology, energy storage technology has attracted wide attention in various industries in recent years. Its core key is low-cost, stable phase-change energy storage materials.
As a kind of solid-liquid phase energy storage material, hydrated salt phase change energy storage material has the advantages of abundant raw materials, high heat storage density, environmental protection, low price, etc., efficient use of solar energy, utilization of industrial waste heat, and inter-seasonal storage. Thermal heating, intelligent greenhouses, food storage and preservation, textile industry have broad market prospects and economic benefits. However, hydrated salt phase change energy storage materials will encounter excessive cooling, phase separation, non-coordinating melting in practical application. , low heat transfer efficiency (low thermal conductivity), volume change, cycle stability, slow crystallization rate and thermochemical stability.
In response to the above problems, the Zhouyuan research team of the Salt Lake Resources Chemistry Laboratory of the Qinghai Salt Lake Research Institute of the Chinese Academy of Sciences has improved the performance of hydrated salt phase change energy storage materials and broadened the application range through comprehensive research. Based on the density functional theory, the solution structure is analyzed and calculated. The main factor affecting the change in the temperature of the molten salt phase transition is the cation in the additive; 2O3Nanoparticles introduced into CaCl 2·6H 2In the O phase change material system, SrCl is used. 2·6H 2O and Al 2O3Nanoparticles as nucleating agents demonstrate the use of nanoparticle nucleating agents 'synergistic effect' to reduce or eliminate supercooling; using graphene as an additive to improve the thermal conductivity of hydrated salt phase change materials and improve their thermal stability and Circulating stability; surface coating to form CaCl by vacuum adsorption 2·6H 2O/diatomaceous earth/paraffin micro-nano core-shell structure phase change energy storage material, verifying the 'limited effect' and 'core-shell effect' of the micro-nano core-shell structure to synergistically improve the phase transformation properties and thermal stability of the material. The research ideas are of great significance for the development of hydrated salt phase change energy storage materials. For details, please refer to Salt Lake Research, 2018, No. 2 'Research Highlights', page 9-15.
Nanoparticles to CaCl
2·6H
2Effect of supercooling degree of O phase change material
Calcium hexahydrate, composite and coated composites change in enthalpy during cycling (a) phase change enthalpy (b) phase transition temperature
