高温储热用 MgCl₂-NaCl-KCl 熔盐的研究进展

With the depletion of fossil fuels and environmental concerns, integrating concentrated solar power (CSP) technology with thermal energy storage (TES) has become essential for efficient solar energy utilization. Molten salts are commonly used as heat storage materials, particularly at medium to high temperatures. Among these, MgCl₂-NaCl-KCl ternary chloride molten salt has been identified as a most promising candidate for next-generation storage systems operating above 700 ℃ thanks to its excellent thermophysical properties, high thermal stability, and low cost. The thermophysical properties of molten salts, such as melting point, specific heat capacity, density, and thermal conductivity, are crucial for the design and optimization of heat storage systems. However, the strong corrosiveness of chloride molten salts towards metallic materials is a major safety concern. To address the current challenges of the MgCl₂-NaCl-KCl molten salt, particularly in obtaining thermophysical property parameters and addressing corrosion issues, recent studies have been reviewed. These studies focus on experimental and simulation approaches to determine the thermophysical properties of the MgCl₂-NaCl-KCl molten salt. Moreover, the corrosion mechanisms affecting common nickel-based and iron-based alloys exposed to this molten salt have been explored based on existing research. Corrosion mitigation strategies are discussed from three aspects: reducing the corrosiveness of the molten salt, improving the corrosion resistance of metallic materials, and implementing corrosion monitoring systems. Finally, the current research status is summarized, and future development directions are proposed.