The Research Of A New Stabilized Phase Change Composite For Thermal Energy Storage

There are many conflicts in energy supply and requirement due to the shortage of the energy sources. Therefore, making use of energy storage to settle the conflict is very important to enhance the energy availability and environmental protection.Phase change materials are becoming research hot spot in energy storage field because of its high thermal storage capacity and nearly constant temperature in phase change, and etc. There is much defect in solid-solid and solid-liquid phase change materials, Such as plastic cystal phenomena of polyatomic alcohol in solid-liquid PCM, super-cooling and phase separation of Inorganic materials in solid-solid PCM. Lately, the research focuses on shaped PCM for overcoming the defect. This composite is composed with one high melting point material and PCM. When phase changed, although the PCM has turned to liquid, the composite still keep solid state for the body material's upholding. This paper put forward an innovate method to prepare nanophase materials with PCM and high melting point inorganic material. Ultimately, organic PCMs have been embedded to silicon dioxide nano-void and shaped PCMs composite have been successfully prepared.Stabilized phase changed composites were prepared with TEOS, ETOH, H₂O and acetamide as raw materials by Sol-Gel process in this paper. Composites were characterized by IR, XRD, TEM etc. Results show that Sol-Gel is simple and Its reaction process is easily controlled. The product made by Sol-Gel is homogeneous phase and high purity, its scale is in nano-scale. Composites have three-dimension porous network structure, good thermal energy capacity, quick thermal energy speed rate and low phase change temperature, which increase the utilization of energy. The composite that contain 30.1% PCM by weight has capacity of thermal energy storage is 176.4J/g and change temperature is 28.8℃. This composite has good stability and low coefficient of cubic expansion. Its maximum coefficient of cubic expansion is only 0.017%. Also moisture absorption of acetamide has been improved. All of these virtues made it been a useful material.This paper discusses the influences of experimental condition on products and analyzes in theory. Furthermore, according to experimental dates and researches in theory, optimum operation conditions have been summarized.