纳米流体的制备、稳定性及热物性研究进展

Research Progress on Preparation,Stability and Thermophysical Properties of Nanofluid

作为一类新型固液两相流体,纳米流体相比于基础流体,其导热系数、表面张力等热物性的优势已逐渐被认可。然而,纳米颗粒的高表面活性以及颗粒间的高吸引力使纳米颗粒极易团聚并沉淀,导致纳米流体的热物性优势被削弱,进而影响传热效果。因此,制备既具优良热物性又具较强稳定性的纳米流体成为将其规模化应用的前提。为此,本文对纳米流体的制备、稳定性与热物性进行了总结分析,归纳了通过磁力搅拌、调节基液pH、超声分散技术、颗粒表面改性技术及添加表面活性剂以促进颗粒的稳定分散的技术特点。通过分析各类参数对纳米流体热物性的影响,指出解决颗粒团聚与沉淀问题的有效研究方向,以期满足纳米流体实际应用的需求。

As a new type of solid-liquid two-phase fluid,nanofluid has been gradually recognized for its advantages in thermophysical properties such as thermal conductivity and surface tension compared with base fluid.Due to the high surface activity of nanoparticles and the high attraction between nanoparticles,nanoparticles are prone to agglomeration and sedimentation,which will weaken the thermophysical property advantages of nanofluid and thus affect the heat transfer efficiency.Therefore,the preparation of nanofluid with excellent thermal properties and strong stability has become the premise of its large-scale applications.To this end,the preparation,stability and thermophysical properties of nanofluid are summarized and analyzed in this paper.Also,the technical characteristics of promoting the dispersion stability of nanoparticles by magnetic stirring,adjusting the pH^(o)f the base fluid,ultrasonic dispersion technology,particle surface modification technology and adding surfactant are summarized.By analyzing the influence of various parameters on the thermophysical properties of nanofluid,the effective research direction to solve the problem of particle agglomeration and precipitation is pointed out,to finally meet the needs of the practical application of nanofluid.