The combination of room-temperature phase change materials (PCMs) and building materials can reduce the energy consumption of heating equipment and improve indoor thermal comfort. In this paper, the novel CaCl₂·6H₂O–CO(NH₂)₂/SiO₂ room-temperature shape-stable composite PCM was fabricated by melt-blending method with CaCl₂·6H₂O as the basic PCM, CO(NH₂)₂ as the phase change temperature regulator and hydrophilic fumed silica (SiO₂) as the carrier. The temperature-regulating effect of CO(NH₂)₂ on CaCl₂·6H₂O and the shape-stabilizing effect of SiO₂ on CaCl₂·6H₂O–CO(NH₂)₂ PCM were emphatically analyzed. The results revealed that the obtained composite PCM with 6% CO(NH₂)₂ and 20% SiO₂ possessed a favorable form-stability, relatively high enthalpy (114.3 J g^-1) and appropriate phase change temperature (21.03 °C) which decreased by 7.81 °C compared with pure CaCl₂·6H₂O (28.84 °C). Furthermore, its small supercooling degree (0.259 °C), low thermal conductivity (0.3667 W·m^-1·K^-1) as well as the excellent cyclic reliability and thermal stability indicated that the composite PCM has good thermodynamic properties, enabling its application for indoor building thermal insulation and even some other areas.

室温相变材料（PCMs）与建筑材料的结合可以降低采暖设备的能耗，提高室内热舒适度。本文以CaCl ₂ ·6H ₂ O为基本PCM,CO,采用熔融共混法制备了新型CaCl ₂ ·6H ₂ O-CO(NH ₂ ) ₂ /SiO ₂室温形状稳定复合PCM。(NH ₂ ) ₂作为相变温度调节剂，亲水性气相二氧化硅(SiO ₂ )作为载体。CO(NH ₂ ) ₂对CaCl ₂ ·6H的调温作用₂ O和SiO ₂对CaCl ₂ ·6H ₂ O-CO(NH ₂ ) ₂ PCM的形状稳定作用进行了重点分析。结果表明，得到的含 6% CO(NH ₂ ) ₂和 20% SiO _{2 的}复合 PCM具有良好的形状稳定性、较高的热函 (114.3 J g ^-1 ) 和合适的相变温度 (21.03 °C)，与纯CaCl ₂ ·6H ₂ O (28.84 °C)相比降低了7.81 °C 。此外，其过冷度小（0.259°C），导热系数低（0.3667 W·m ^-1 ·K ^-1)以及优异的循环可靠性和热稳定性表明复合相变材料具有良好的热力学性能，使其可应用于室内建筑隔热甚至其他一些领域。