Modification Of High Temperature Heat Transfer Medium Ternary Carbonate

With the problem of environmental pollution and energy shortage becoming more and more terrible,all countries in the world are looking for clean new energy.Solar thermal power generation is a new form of solar energy resource utilization,and the commercialization of solar thermal power generation is very important to solve China's energy and environmental problems.One of the key technologies is to achieve large-scale continuous energy storage,to solve discontinuity and instability problem of solar energy,which requires the development of excellent heat storage materials.Carbonate molten salt has been widely concerned and studied in the development of heat storage materials due to its good stability,high thermal capacity,good thermal conductivity,wide range of working temperature,low steam and low cost.In this paper,the specific heat capacity of ternary carbonate was improved by adding nanoparticles in ultrasonic water solution.Firstly,three different crystallization methods were used to evaporate water to obtain molten salt nanocomposite materials.The specific heat capacity of each sample was measured and compared to determine the optimal crystallization method.The changes of melting point,phase change latent heat,decomposition temperature and sensible heat storage cost of samples before and after adding nanoparticles were investigated;Then,using model calculation and test analysis to study the relationship between the specific heat capacity and microstructure of ternary carbonate and molten salt nanocomposite materials,and to predict the mechanism of specific heat capacity strengthening;Finaly,using the optimal method to prepare molten salt nanocomposites.The effects of nanoparticle particle size,nano-particle addition and nano-particle dispersion concentration on specific heat capacity,melting point and phase change latent heat of composite materials were investigated;The effects of different preparation methods on thermal properties of composite materials were investigated by comparing melting method and ultrasonic solution method.The results show that droplet crystal method is a better method to prepare molten salt nanocomposites.The formation of the bar nanostructure is the reason for the specific heat capacity enhancement of molten salt nanocomposites;The optimized experimental conditions of the preparation of molten salt nanocomposites is:using ultrasonic aqueous solution method,30 nm in diameter of silicon dioxide do additives,the quality of the nanoparticles take 1%percentage,nanoparticle dispersion concentration take 1 mg SiO2/15 mL HZO,chase through droplet crystal method preparation of composite materials.