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为了明晰工质种类对微通道传热性能的影响,研究了导热系数λ,比热容cp,动力粘度μ和密度ρ影响微通道传热性能的规律。首先研究了水和煤油在构造的粗糙微通道中流动与传热性质的差异,然后将各个因素孤立的研究其对于整体传热性能的影响。结果发现,在粗糙微通道中的层流充分发展流动状态,Poiseuille数(Po)基本不随Re变化,也不随工质热物性变化;水和煤油的Nusselt数(Nu)都随Re的增大而增大,且煤油的Nu的数值和随Re的增长率都大于水的对应值。研究还发现,Nu随着λ的增加而减小,随着cp和μ的增加而增加,不随密度ρ变化;同时,λ和μ对Nu的影响比cp大。
In order to clarify the effect of working medium on the heat transfer performance of microchannels, the heat transfer coefficient λ, the specific heat capacity cp, the dynamic viscosity μ and the density ρ were investigated. Firstly, the difference of flow and heat transfer properties between water and kerosene in the rough microchannels was studied. Then the influence of various factors on the overall heat transfer performance was studied in isolation. The results show that the laminar flow in the rough microchannels fully develops the flow state. The Poiseuille number (Po) basically does not change with Re and does not change with the thermal properties of the working fluid. The Nusselt number (Nu) of water and kerosene increases with Re Increase, and the Nu value of kerosene and with the growth rate of Re are greater than the corresponding value of water. The study also found that Nu decreases with the increase of λ, increases with the increase of cp and μ, and does not change with the density ρ; at the same time, λ and μ affect Nu more than cp.