Molten Salt Phase Change Heat Storage Material Preparation And Research In Solar Thermal Power Generation

With the new change in world energy supply and new trend in international energy development,china,which it's still in the process of industrialization and urbanization,must promote energy production and consumption revolution,develop new clean energy technology;Solar energy as a renewable energy is affected by light intensity,day and night,climate change,and geographic location,and it has the shortage of discontinuity and instability.Heat storage technology can store the intermittent heat and release the heat when it's need.It can make up for the lack of heat,realize the continuous operation of the power station and continuous power supply for the user,and the manufacture of thermal storage material is the key in this research.Thought study of the Chinese and foreign literature and discuss with scientific researcher in related areas,combining with the before findings of our research group,we determine the sodium nitrate and potassium nitrate as the main raw material.In the first phase,the different proportion of mixed sodium nitrate and potassium nitrate are produced by means of the static melting method.The best ratio the the best performance is determined by testing the latent heat,melting point,thermal conductivity,thermal stability,corrosion and other thermal properties of mixed sodium nitrate-potassium nitrate in different proportions.Secondly,the expanded graphite,metallic tin and neodymium nitrate with different mass fractions were added to the the mixed molten salt with the best ratio of sodium nitrate-potassium nitrate.By adding different additives,thermal properties of the mixed molten salt is improved,of which the purpose is to explore the phase change thermal storage materials meeting the requirements of the thermal storage technology.Through the test analysis of the experimental sample,the mixed molten salt with high latent heat,low corrosion,suitable melting point and good thermal stability,can be used as heat storage material in solar thermal power generation and other storage devices.The addition of expanded graphite to mixed molten salt,whose melting point is further promoted by the addition of metallic tin,is the most innovation points of this paper.The experimental results show that the addition of a small amount of nitrate and neodymium nitrate can cause a certain change in the thermal properties of the mixed molten salt.The three has good compatibility,low melting point,high latent heat of phase change,and good thermal stability.No new material is generated in process,and the requirement of the thermal storage materials is met.