【摘要】 以Na₂CO₃·10H₂O（SCD）、Na₂HPO₄·12H₂O（DHPD）为相变主体制备了共晶体系，通过绘制凝固点变化图与DSC测试共同确定在m（SCD）∶m（DHPD）=4∶6时形成共晶，FTIR和XRD结果显示，2种水合盐间没有发生化学反应，但其晶型结构发生改变。通过添加质量分数为2%的Na₂SiO₃·9H₂O作为成核剂降低体系的过冷度，且经历50次相变循环体系未出现相分离，相变焓值仅下降0.25%。进一步使用质量分数为25%的气相SiO₂作为支撑材料，采用浸渍法制备了相变前后形状稳定的共晶水合盐/SiO₂定形相变材料（SSPCM）。所得SSPCM的相变温度为24.08℃，相变焓值为146.6J/g，过冷度为0.55℃，热导率为0.4571W/（m·K）。同保温泡沫相比，其可将模拟房内部中心温度的升温时间延长了1.81倍，降温时间延长了0.39倍。更多还原

【Abstract】 The eutectic system was prepared from Na₂CO₃·10H₂O（SCD） and Na₂HPO₄·12H₂O（DHPD）phase change materials, and it was found that the eutectic system was formed when m（SCD）∶m（DHPD）=4∶6 by a solidification point variation diagram construction and DSC test. FTIR and XRD results revealed that the crystal structure was changed though there was no chemical reaction between the two hydrated salts.Na₂SiO₃·9H₂O with a mass fraction of 2% was added as nucleating agent to reduce the undercooling of the system. Meanwhile, the system showed no phase separation and only a 0.25% decrement in enthalpy after undergoing 50 cycles of phase transition. Furthermore, a shape-stablized phase change material（SSPCM）consisting of eutectic hydrate/SiO₂ with a mass fraction of 25% was prepared by impregnation. The obtained SSPCM exhibited a phase transition temperature of 24.08 ℃, an enthalpy of 146.6 J/g, an undercooling of 0.55 ℃, and a thermal conductivity of 0.4571 W/（m?K）. Compared with conventional insulation foam, the SSPCM extended the heating time to raise the simulated indoor core temperature by 1.81 times and prolonged the cooling time by 0.39 times.更多还原