本项目提出对纳米蓄冷工质中CNTs进行定向分布调控，形成高定向导热蓄冷工质。通过轴向CNTs形成的导热网链为蓄冷工质的热传导提供通道，提高凝固过程晶体生长表面的热量传输能力。主要对磁场作用下CNTs的定向调控机制及其强化冰蓄冷凝固过程进行研究。探寻磁性粒子负载改性CNTs水基纳米流体的制备工艺，获得分散稳定性良好的CNTs磁性纳米流体；针对水基CNTs纳米流体为研究对象，以磁场诱导技术为实验手段，将负载改性CNTs磁性纳米流体置于磁场中，研究定向排列CNTs纳米流体的过冷度抑制情况和凝固速率的变化规律；通过实验研究和理论分析揭示高定向导热CNTs纳米粒子在溶液中的非均匀成核及晶体生长机制，建立CNTs纳米流体空间不连续与非均匀化凝固过程中非稳态传热的预测模型。本课题的研究对深入认识纳米流体强化相变凝固特性具有学术价值，也为蓄冷空调技术中发展高效节能的蓄冷工质奠定基础。

In this project, the directional CNTs in cool storage media are distributed to form high orientation heat conduction working fluid. The thermal conduction network chains formed by axially distributed CNTs provide a channel for thermal conduction of cool storage media and improve the heat transfer capacity of crystal growth surface during solidification. Specifically, the effect of directional arranged CNTs that induced by magnetic field on the enhanced cold storage characteristics will be investigated. The preparation of water based CNTs nanofluid, which is modified by magnetic particles, will be studied to obtain CNTs magnetic nanofluid with good dispersion stability. When water based CNTs nanofluid is used as working fluid, experiments are conducted to measure subcooling degree and solidifying rate of orientation arranged CNTs nanofluid under magnetic field. Experimental study and theoretical analysis will be carried out to study the heterogeneous nucleation and crystal growth mechanism of CNTs magnetic nanofluid. As a result, a prediction model of unsteady heat transfer is established during the space discontinuity and heterogeneous phase transformation process for CNTs nanofluid. The research is of academic value for understanding the solidification characteristics of nanofluid and also has significance on developing energy-efficient working fluid in the ice storage air conditioning system.