太阳能热发电中铝基合金热循环后热特性研究

对太阳能热发电中的铝基合金储热材料分别经过400、800、1 200次的热循环实验,采用扫描电子显微镜对热循环后合金的显微组织和成分进行表征,对合金的热导率和膨胀系数进行了测试。研究表明,储热材料随循环次数的增加,共晶Si在一个方向相对循环前迅速长大,且α相基体存在疏孔和不同程度的氧化;热导率明显降低;线膨胀系数略有降低。随Si含量的增加热导率和线膨胀系数呈下降趋势。

Study on Thermal Proprety of Al-base alloy after Thermal Cycling in Solar Thermal Power Generation

Thermal cycling test of aluminum based alloy thermal energy storage material in solar thermal power generation by 400,800,1200 times, the microstructure and composition, thermal conductivity and expansion coefficient of the alloy after thermal cycling were measured by scanning electron microscope (SEM), electrical conductivity and thermal expansion apparatus,the thermal conductivity, thermal expansion characteristics and microstructure of the alloy under different thermal cycles were revealed by the combination of microscopic analysis, solidification and free electron theory. The study shows that the thermal storage materials increase with the number of cycles, and the eutectic Si grows rapidly in one direction,and the phase matrix has the pores and different degrees of oxidation.The coefficient of linear expansion is decreased slightly, while the thermal conductivity is obviously decreased. With the increase of Si content, the thermal conductivity and linear expansion coefficient showed a decreasing trend.