碳纳米管-无机盐复合成核剂对MgCl2∙6H2O-CaCl2∙6H2O体系储热性能的影响

Thermoproperties research on the carbon nanotube-inorganic salt composite nucleating agents under the MgCl2∙6H2O-CaCl2∙6H2O system

摘要:

本论文以MgCl₂?6H₂O-CaCl₂?6H₂O为研究体系,探讨在诱导结晶成核过程中,同时引入羟基化碳纳米管(CNTs)和SrCl₂?6H₂O-SrCO₃作为复合成核剂对体系储热性能的影响规律。实验结果表明,CNTs单独作为成核剂,可以使体系过冷度降低,并且随着CNTs加入量的增加,体系的过冷度逐渐减小；当CNTs和SrCl₂?6H₂O-SrCO₃作为复合成核剂同时引入时,可以进一步降低体系的过冷度,其中CNTs、SrCO₃和SrCl₂?6H₂O加入量分别为0.25 wt.%、1 wt.%和3 wt.%时,MgCl₂?6H₂O-CaCl₂?6H₂O体系的过冷度最小(约为0.6 ℃)。MgCl₂?6H₂O-CaCl₂?6H₂O相变材料过冷度减小的原因,是因为复合成核剂使体系具有较好的导热性能和较高的的相变潜热。

关键词:碳纳米管;复合成核剂;相变材料;过冷度

Abstract:

Effect of using SrCl₂?6H₂O-SrCO₃and hydroxylate carbon nanotubes (CNTs) as composite nucleating agent on the energy storage properties in the induced crystallization nucleation process of MgCl₂?6H₂O-CaCl₂?6H₂O were investigated. It is suggested that the addition of CNTs can reduce system supercooling degree (SSD), which decreases with increased CNTs. When the composite nucleating agents consisting SrCl₂?6H₂O-SrCO₃ and CNTs were introduced SSD can be further decreased when the composite nucleating agents consisting SrCl₂?6H₂O-SrCO₃ and CNTs were introduced because of the good thermal conductivity and high phase change latent heat. SSD decreased to a minimum of 0.6 ℃ when the ratio of CNTs, SrCO₃ and SrCl₂?6H₂O was optimized as 0.25 wt.%、1 wt.% and 3 wt.%, respectively.

Key words:carbon nanotubes; composite-nucleating agent; phase change materials; supercooling degree