Research On Thermophysical Properties And Thermal Storage Properties Of Phase Change Thermal Storage Aluminum Alloys

The use of solar power can effectively alleviate the challenges of energy shortage, resource exhaustion and environmental pollution that the traditional thermal power generation brought about. Concentrating solar power systems are highly efficient and easy-to-large-scale. However there is often a mismatch between the acquisition of solar energy and the actual energy demand. Therefore thermal storage subsystems need to be equipped to achieve a continuous supply of energy. The efficiency of thermal storage system depends largely on the heat storage medium used. Phase change thermal energy storage materials have great application prospects because they can store large amounts of latent heat at a substantially constant temperature. And among the numerous high temperature phase change heat storage materials, aluminum alloy showed great potential for development due to its excellent performance.In this paper, based on the composition design of aluminum alloy phase change heat storage materials, a variety of binary and ternary aluminum alloys were prepared by high temperature melting and their elemental compositions were tested using the combination of titration method, gravimetric method and inductively coupled plasma atomic emission spectrometry(ICP-AES). Besides, the phase change temperatures, latent heats and specific heats of the aluminum alloy phase change materials were measured using differential scanning calorimetry(DSC) and their thermal diffusivities at different temperatures were measured with the method of laser pulse, on the basis of which the corresponding themal conductivities were calculated. As a result, the influence laws of main thermophysical properties by the kinds and amount of elements addition for the aluminum alloys were obtained, and the formulas to calculate the specific heats and thermal conductivities at different temperatures were given respectively. In addition, the total heat storage capacity of the samples in the temperature range of 400-800 ℃ were calculated and analyzed, and the influence laws of heat storage unit mass and heat storage unit volume by the kinds and amount of elements addition for the aluminum alloys were obtained. Finally, after a comprehensive comparation, the aluminum alloy thermal energy storage materials with optimal thermal storage properties were given, which provided basic physical parameters and reference for the associated thermal storage system design.