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采用物理和化学分散相结合的方法分别制备了Cu-Na_2SO_4·10H_2O,Al-Na_2SO_4·10H2O及C-Na_2SO_4·10H_2O纳米复合相变储能材料,探讨纳米Cu粉,纳米Al粉及纳米C粉对Na_2SO_4·10H_2O过冷及相分层的影响,并对CNa_2SO_4·10H_2O复合相变储能材料的导热系数,热扩散系数,比热,相变潜热及形貌进行分析。结果表明:纳米材料的添加使得Na_2SO_4·10H_2O的过冷显著降低,分别为1.8℃,2.1℃,1.2℃;纳米Cu粉及纳米Al粉复合相变储能材料相变循环后失效,而纳米C粉复合相变储能材料无明显相分层现象;随着纳米C含量的增加,复合相变储能材料导热系数增高,热扩散系数增高,比热降低,复合相变储能材料在融化和结晶状态下,导热系数都随着温度升高而增大;相变循环50次后的4%C-Na_2SO_4·10H_2O复合材料相变潜热值为188.3 J/g。
Cu-Na_2SO_4 · 10H_2O, Al-Na_2SO_4 · 10H2O and C-Na_2SO_4 · 10H_2O nanocomposite phase-change energy storage materials were prepared by a combination of physical and chemical dispersion methods, respectively. The effects of nano Cu powder, nano Al powder and nano- Na_2SO_4 · 10H_2O supercooling and phase stratification. The thermal conductivity, thermal diffusivity, specific heat, latent heat and morphology of CNa_2SO_4 · 10H_2O composite phase change energy storage materials were analyzed. The results show that the supercooling of Na_2SO_4 · 10H_2O decreases by 1.8%, 2.1 ℃ and 1.2 ℃, respectively. The phase transformation of nanocrystalline Cu powder and nano Al powder phase change energy storage cycle fails, With the increase of nano-C content, the thermal conductivity of composite phase change energy storage materials increased, the thermal diffusivity increased, the specific heat decreased, and the composite phase change energy storage materials melted and In the crystalline state, the thermal conductivity increases with the increase of temperature. The latent heat value of 4% C-Na_2SO_4 · 10H_2O composite after 50 cycles of phase transformation is 188.3 J / g.