多孔微通道流动沸腾换热特性的实验研究

Experimental Study on Flow Boiling Heat Transfer Characteristics of Porous Microchannels

本文通过实验的方法对烧结的多孔微通道和铜基微通道的沸腾换热性能和流动不稳定进行研究。实验工质选用去离子水,采用的铜粉粒径分别为30μm、50μm、90μm,烧结底厚为200μm和400μm。采取控制变量的方式,研究改变入口温度、铜粉粒径大小、入口流量对多孔微通道和铜基微通道换热性能的影响。研究表明:多孔微通道最优的厚度粒径比在2~5之间,在此区间的多孔微通道可以提高沸腾传热的性能。其中厚度粒径比为2和4的多孔微通道的最大换热系数是铜基微通道的换热系数的5倍。多孔微通道相对于铜基微通道有更好的换热能力,有着较低的壁面温度。

In this paper,the boiling heat transfer performance and flow instability of sintered porous microchannels and copper-based microchannels are studied through experiments.The experimental working medium used deionized water,the particle size of the copper powder used was 30μm,50μm,90μm,and the thickness of the sintered bottom was 200μm and 400μm.The method of controlling variables was used to study the effect of changing the inlet temperature,copper particle size and inlet flow rate on the heat transfer performance of porous microchannels and copper-based microchannels.Studies have shown that the optimal thickness-to-diameter ratio of porous microchannels is between 2~5,and porous microchannels in this interval can improve boiling heat transfer performance.The maximum heat transfer coefficient of porous microchannels with thickness-to-particle ratios of 2 and 4 is 5 times that of copper-based microchannels.Compared with copper-based microchannels,porous microchannels have better heat transfer capabilities and have lower wall temperatures.