On May 25, China Solar Thermal Alliance (hereinafter referred to as CSTA) released a standard on “Molten salt corrosion testing and assessment methods for solar thermal power generation". This standard specifies the corrosion test and evaluation method of molten salt on metal materials in solar thermal power plant, and is suitable for the corrosion test and evaluation of molten salt on metal materials in solar thermal power plant. The standard will be implemented on June 25, 2021.
Molten salt is used as a heat transfer and heat storage material for solar thermal power generation (CSP plant). It can generally be divided into nitrate/nitrite, carbonate, chloride and fluoride salt. Nitrate/nitrite has low melting point, weak corrosiveness, and low price. It has become the first choice for medium and high temperature molten salt heat transfer and storage materials. Solar salt (60%NaNO₃+40%KNO₃) has been successfully applied to solar thermal power generation. With the development and construction of solar thermal power stations, the safety of molten salt heat storage systems has also received more and more attention. Among the first batch of solar thermal power generation demonstration projects in China, 90% of the projects equipped with molten salt heat storage system, which have become the mainstream in the industry. At present, the molten salt used in the heat transfer and storage system of the CSP station is mainly nitrate molten salt. During the entire life cycle operation of the CSP station, the molten salt needs to experience tens of thousands of large temperature changes and fluctuations. During the design life of the power station, molten salt will be stored in the molten salt tank in a high-temperature liquid state. The thermal fatigue, thermal stress and corrosion resistance of the molten salt tank are the huge tests. The molten salt corrosion has become the most important problem, which directly affects the life and safety of the whole system. Therefore, proposing and formulating this standard is of great significance to the continuous development of the molten salt heat storage field and the entire CSP industry.
This standard was drafted Shanghai Institute of Applied Physics, Chinese Academy of Sciences, together with Sun Yat-sen University, Beijing University of Technology, China Salt Jintan Salt Chemical Co., Ltd., Shanxi Wojin New Energy Co., Ltd., and Institute of Electrical Engineering, Chinese Academy of Sciences, Zhejiang University, China Special Equipment Inspection and Research Institute, Qinghai Salt Lake Research Institute of Chinese Academy of Sciences, etc.