相变蓄热材料是太阳能热发电系统蓄热环节的关键。Al-Si-Cu三元合金作为相变蓄热材料具有性能稳定、衰减指数低、蓄热性能优良的特点。在实验的基础上,采用DSC、Hotdisk等方法对不同金属含量的Al-Si-Cu合金的热物性进行研究,同时对其封装材料进行了选择;基于不同形状蓄热单元,用Fluent软件进行模拟,最终选择了一个圆形相变蓄热单元和一个正六边形蓄热模块。结果表明：Al-Si-Cu三元合金相变蓄热材料集合了Al-Cu合金质量潜热大和Al-Si合金体积潜热大的优势;圆形结构蓄热单元换热性能最优;正六边形的模块能有效提高空间利用率,且更易于拼接,这对大型相变蓄热装置在工程中的应用具有重要意义。
Phase change materials are the key to heat storage in solar thermal power system. As a phase change heat storage material, Al-Si-Cu ternary alloy has the characteristics of stable performance, low attenuation index and excellent heat storage performance. On the basis of experiments, the thermal properties of Al-Si-Cu alloys with different metal contents were studied by DSC, Hotdisk and other methods, and the packaging materials were selected. Based on the thermal storage units with different shapes, Fluent software was used for simulation, and a circular phase-change thermal storage unit and a regular hexagon thermal storage module were finally selected. The results show that the phase-change heat storage material of Al-Si-Cu ternary alloy has the advantages of large mass latent heat of Al-Cu alloy and large volume latent heat of Al-Si alloy, and the presence of Cu can protect the oxidation of liquid aluminum alloy and reduce the corrosion of liquid aluminum alloy to the container. The heat transfer performance of the round structure heat storage unit is the best. The regular hexagonal module can effectively improve the space utilization rate and is easier to be assembled, which is of great significance to the application of large phase change heat storage device in engineering.
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