复合相变材料储热水泥板的热性能研究

以十八烷(OC)为相变材料、膨胀石墨(EG)为支撑结构制备出OC质量含量为90％的十八烷/膨胀石墨复合相变储热材料( OC/EG-PCM).将OC/EG-PCM掺入到普通硅酸盐水泥中,制备出了相变材料质量含量分别为2％、5％、7％、10％的标准储热水泥立方体(70.7×70.7×70.7 mm3)和储热水泥板(10×100×l00 mm3),测量了储热水泥立方体的表观密度和抗压强度,以及储热水泥板的导热系数和储热性能.结果表明,随着OC/EG-PCM质量含量的增加,储热水泥立方体的表现密度和抗压强度逐渐下降,储热水泥板的导热系数也近似于线性减小,储热水泥板的上下表面温差则逐渐增大.当OC/EG-PCM的质量含量为10％时,储热水泥立方体的抗压强度大于10MPa,储热水泥板的上下表面温差大于4.0℃.

Study on the thermal properties of cement boards based on composite phase change material

Octadecane/expanded graphite composite phase change material(OC/EG-PCM) containing 90wt% of OC was prepared,in which EG acted as the supporting material,OC served as latent heat storage material.By blending the OC/EG-PCM with ordinary portland cement in the mass ratio of 2%,5%,7%,10%,respectively,the standard thermal storage cement cubes(70.7 × 70.7 × 70.7 mm3) and the thermal storage cement boards(10 × 100 × 100 mm3) were prepared.The apparent density and compressive strength of the standard thermal storage cement cubes,as well as the thermal conductivity and the thermal performance of the thermal energy storage cement boards were measured.The results indicated that the apparent density and the compressive strength of the cement cubes decreased with the increase mass content of the OC/EG-PCM,the thermal conductivity of the thermal storage cement boards declined linearly,and the temperature difference between the upper and lower side of the thermal storage cement boards increased gradually.The compressive strength of the standard cube was bigger than 10MPa,and the temperature difference was higher than 4.0℃ when the mass fraction of the OC/EG-PCM reached 10%.