纳米颗粒悬浮液池内泡状沸腾的实验研究

本文对纳米颗粒悬浮液在平壁面上池内沸腾进行了实验研究。实验用的纳米粒子为26 nm的铁粉和13 nm的三氧化二铝纳米粉末,基液为去离子水。分别配成体积浓度为0．1％, 1％和2％的悬浮液。实验结果表明,纳米悬浮颗粒对液体沸腾换热过程的影响会随着纳米颗粒性质,颗粒浓度及热流密度大小的不同而出现不同的效果;加入纳米颗粒后, 对基液沸腾换热的影响存在着两个相反的作用机制,它们分别为:纳米颗粒增强了液体内部的热量迁移能力(热物性的影响)和改变了加热面的表面结构特性(加热面特性的影响)。

EXPERIMENTAL STUDY OF POOL BOILING HEAT TRANSFER OF NANO-PARTICLE SUSPENSIONS ON A PLATE SURFACE

In this paper an experimental investigation of pool boiling heat transfer at horizontal plate surface is conducted for 26 nm Fe-water and 13nm Al2O3-water nano-particle suspensions. The experimental results show that there are two effects which influence the boiling heat transfer of liquid with nano-particle suspension. Nano-particles increase the thermal conductivity of boiling fluid, which enhances the convection heat transfer induced by the micro-layer evaporation and bubble upward motion near the boiling surface (termed as a thermal effect); Nano-particles might cover or trap into some cavities on the boiling surface, which causes these cavities decreasing their nucleation activity or even losing their activity during the boiling (termed as a surface effect). The boiling heat transfer for nano-particle fluid would be enhanced or deteriorated depending on the summarization of these two effects.