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

Abstract

The invention discloses a method for preparing a molten salt porous silicon-based composite phase-change heat storage material: first, the mixed molten salt and the porous silicon-based carrier material are pulverized by an ultrasonic pulverizer, and placed in a constant temperature drying box for standby; Take out the mixed molten salt and porous silicon-based carrier material from the box respectively, and initially mix them, and stir again with an electronic stirrer to fully mix the mixed molten salt and porous silicon-based carrier material; The mixed molten salt and porous silicon-based carrier material are pressed into shape; the pressed silicon-based composite material is placed in a muffle furnace for sintering, and after sintering, it is directly cooled to room temperature in the muffle furnace to obtain a molten salt porous silicon-based composite material. Phase change heat storage materials. The composite phase change heat storage material prepared by the invention has the advantages of low heat storage cost, high melting latent heat value, high decomposition temperature, high mechanical strength, good thermal stability, and good chemical stability, and can be used in solar thermal power generation systems.

Description

technical field [0001] The invention relates to the technical field of composite phase-change heat storage materials. Specifically, the invention relates to a preparation method of a molten salt porous silicon-based composite phase-change heat storage material. Background technique [0002] With the rapid development of modern society, the total energy consumption in the world has risen sharply. New and renewable energy sources such as solar energy, geothermal heat, industrial waste heat, and low-grade waste heat have become hot spots in the world for development and utilization, and heat storage technology can temporarily Unutilized or excess heat is stored to address uneven and intermittent problems in heat supply and demand. [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, inor...

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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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