Preparation method of molten salt porous silicon-based composite phase change heat storage material

Abstract

The invention discloses a preparation method of a molten salt porous silicon-based composite phase change heat storage material. The preparation method comprises the following steps: firstly, respectively crushing mixed molten salt and a porous silicon-based carrier material by using a supersonic crusher, and putting the crushed materials into a constant-temperature drying box for later use; then respectively taking out the mixed molten salt and the porous silicon-based carrier material from the constant-temperature drying box, preliminarily mixing, and stirring again by using an electronic stirrer, so that the mixed molten salt and the porous silicon-based carrier material are fully and uniformly mixed; carrying out compression molding on the uniformly mixed molten salt and the porous silicon-based carrier material by using a constant-stress pressure testing machine; and sintering the pressed and molded silicon-based composite material in a muffle furnace, and directly cooling to room temperature in the muffle furnace after sintering is finished, so as to obtain the molten salt porous silicon-based composite phase change heat storage material. The prepared composite phase change heat storage material has the advantages of being low in heat storage cost, high in melting latent heat value, high in decomposition temperature, high in mechanical strength, good in heat stability and chemical stability and the like, and can be used for a solar thermal power generation system.

Description

technical field [0001] The invention relates to the technical field of composite phase change heat storage materials. Specifically, it is a preparation method of molten salt porous silicon-based composite phase change heat storage material. Background technique [0002] With the rapid development of modern society, the world's total energy consumption has risen sharply. New and renewable energy sources such as solar energy, geothermal energy, industrial waste heat, and low-grade waste heat have become hot spots for development and utilization by countries all over the world. Unused or excess heat is stored to solve the problem of inhomogeneity and intermittency in the heat supply and demand process. [0003] At present, in the field of heat storage materials, the commonly used phase change heat storage materials are mainly divided into inorganic phase change heat storage materials and organic phase change heat storage materials. Among them, inorganic phase change heat stora...

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Problems solved by technology

Patent CN102031090A discloses a carbon-based composite phase change heat storage material with graphite as the carrier and inorganic salt hydrate or high-temperature inorganic salt phase change material as the core material. The maximum phase change temperature of the material is 225°C, less than 300°C , cannot be used in solar power generation systems, and the preparation process of the composite phase change heat storage material disclosed in this patent is relatively complicated, and its thermal stability needs to be improved

Due to the rich specific surface area of ​​silicon-based materials, the phase change materials can be encapsulated inside the pores through the adsorption of the pores and the chemical bonds inside the pores, which can effectively prevent the phase change materials from being released without affecting the fluidity of the phase change materials. Leakage occurs in the molten state, which has great advantages compared with other carrier materials, but there is little research on the preparation of molten salt composite phase change heat storage materials using porous silicon-based materials as carriers

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