二氧化硅纳米流体强化对流换热研究进展

Research progress on silica nanofluids for convective heat transfer enhancement

随着半导体技术和电子技术的快速发展,高集成化和高性能化的微电子器件在航空航天、能源、医疗和汽车工业等领域发挥着越来越重要的作用.为了避免出现高热流密度引起的器件高温失效问题,对微电子器件进行有效热管理是非常关键的.传统的风冷和液冷技术不仅功耗高而且散热效率低,严重影响了器件的稳定性和可靠性.近年来,国内外研究者提出了多种新型被动式和主动式强化换热技术.其中,纳米流体强化换热技术由于成本低、操控灵活和形式多样性的特点,受到了广泛的关注.特别是对于二氧化硅纳米颗粒,良好的机械和化学稳定性、丰富的结构形式和多样化的合成方法等优势引起了研究者极大的兴趣.目前,二氧化硅纳米流体在导热、对流和辐射传热方面都有显著的强化性能.以电子器件液冷技术为背景对二氧化硅纳米流体在强化对流换热的研究进展进行了系统综述,首先介绍了二氧化硅纳米流体的性质和制备方法,然后讨论并总结了二氧化硅纳米流体在单相对流(自然对流和强制对流)和相变对流(池沸腾和流动沸腾)领域的研究现状,最后强调二氧化硅纳米流体对流换热技术存在的问题以及未来发展的方向,为建立高性能纳米流体液冷换热技术体系提供相应的思路和参考.

With the rapid development of semiconductor and electronics technologies,high-integration and high-performance microelectronic devices play more important roles in industrial fields,such as the aeronautics and astronautics,energy,medical,and automobile fields.To avoid thermal failure in high heat flux conditions,effective thermal management of microelectronic devices is critical.Conventional air and liquid cooling approaches suffer from not only high power consumption but also low heat dissipation efficiency,considerably limiting the stability and reliability of microelectronic devices.In recent years,researchers proposed many passive(such as nanofluids,surface roughness,and heating element structures)and active(such as the acoustic,electric,and magnetic fields)heat transfer enhancement approaches.Because of its low cost,flexible control,and diverse forms,the nanofluid approach has attracted considerable attention.To solve the low thermal conductivity issue of conventional working fluids(such as water,ethylene glycol,and mineral oil),researchers have developed a series of particulate forms,including but not limited to silica dioxide(SiO_(2)),aluminum oxide(Al_(2)O_(3)),titanium dioxide(TiO_(2)),carbon nanotube,copper(Cu),silver(Ag),silicon carbide(SiC),diamond,iron oxide(Fe_(2)O_(3)),zinc oxide(ZnO),magnesium oxide(MgO),and cupric oxide(CuO).Particularly,silica(SiO_(2))nanofluids,with their good mechanical and chemical stability,abundant structures,and diverse preparation methods,make them interesting to researchers.To date,SiO_(2) nanofluids exhibit outstanding intensification performance in the fields of conduction,convection,and radiation heat transfer.This study provided a systematic overview of the research progress on SiO_(2) nanofluids for convective heat transfer applications.First,the physicochemical properties and preparation methods(i.e.,one-step and two-step methods)of SiO_(2) nanofluids were introduced.Further,the state of the art of SiO_(2) nanofluids for single-phase convection and phase change convection applications was summarized,and the numerical simulation and experimental observation results of natural convection,forced convection,pool boiling,and flow boiling were tabulated and discussed in detail.Finally,the current remaining challenges and future research directions were highlighted in terms of the in-depth heat transfer enhancement principles,practical industrialization applications,systematic and accurate evaluation of heat transfer performance,preparation and characterization strategies,exploration of a high-diversity library of particulate structures,and optimization of heat exchanger apparatus.We believe that this review article can shed new insights into the rational design and preparation of advanced SiO_(2) nanofluids and provide important guidelines to develop robust nanofluid-based liquid cooling heat sinks.