芒硝/蛭石复合材料蓄冷-释冷性能研究

Investigation of cold storage-release performance of mirabilite / vermiculite composite cold storage material

中文关键词: 蓄冷材料  膨胀蛭石  比热容  热导率  循环稳定性

英文关键词: cold storage material  expanded vermiculite  specific heat capacity  thermal conductivity  cycle stability

中文摘要:

      采用真空浸渍法制备了芒硝/膨胀蛭石（EV）复合蓄冷材料（CPCM），其中9wt%的氯化铵为相变温度调节剂，3wt%的硼砂(Borax)为成核剂；经筛选得到，EV与相变材料的最大负载质量比为1：6。制备的CPCM相变温度为16.2℃，潜冷蓄冷量为105.98kJ/kg，因为EV载体材料提高了比热容，使总蓄冷量达到120.68kJ/kg。芒硝基相变材料(PCM)与CPCM因EV的负载导热系数有所提升，并有效改善了无机盐类相变材料所产生的相分离问题。搭建循环测试装置，确定了CPCM的最优工况，并对CPCM进行100次融化-凝固循环，循环后对CPCM片层进行了SEM测试。结果表明，CPCM热性能稳定，片层无明显破裂，无相分离发生。复合相变蓄冷材料在24℃进口温度时释冷效果明显。故所制备的复合蓄冷材料CPCM适用于空调冷能储存，提高用冷经济性。

英文摘要:

      Mirabilite/expanded vermiculite (EV) composite phase change material (CPCM) was prepared by vacuum impregnation method,among them, 9wt% ammonium chloride is the phase change temperature regulator, 3wt% sodium borate(Borax) is the nucleating agent;and the maximum load mass ratio of EV to phase change materials is 1:6. The phase change temperature of hydrated salt is 16.2℃, the latent cold storage capacity is 105.98kJ/kg,and the specific heat capacity of the material is increased by EV carrier,so that the total cold storage capacity reaches 120.68kJ/kg.The thermal conductivity of mirabilite-basic phase change materials (PCM) and CPCM was measured.It was found that the thermal conductivity of PCM was improved after EV loading,and the phase separation problem of inorganic salt phase change materials was effectively improved.Build a loop teseted device to determine the best working condition of CPCM,100 melting-solidification cycles were carried out for CPCM,and SEM tests were carried out for the layers of CPCM after the cycles.The results show that the thermal performance of CPCM is stable,and there is no obvious fracture and phase separation.The refrigeration effect of CPCM is obvious when the temperature of inlet is 24℃.It shows that CPCM is hopeful to be used in cold energy storage of air conditioning and reduce the operating cost.