窄环隙内单相对流换热的实验研究

Experimental Investigation on Single-phase Convection Heat Transfer in Narrow Annulus

鉴于流体在小尺度流道内流动换热时所表现出的特殊性 ,对水在竖直环隙内受迫流动时的单相对流换热特性进行了实验研究 ,两组实验件的环隙宽度分别为 0 9mm和 2 4mm。实验结果表明 ,窄环隙可以对单相对流换热起到强化作用 ,但较 2 4mm环隙而言 ,0 9mm环隙不但不能进一步强化换热 。

Considering the special heat transfer characteristics of fluids flowing through ducts with small gap sizes, experiments are performed to investigate the heat transfer characteristics of single phase water, which is forced to flow through vertical annuli with gap size of 0.9 mm and 2.4 mm. The results show that narrow annulus can enhance the single phase heat transfer, but instead of further enhancing the heat transfer, the annulus with gap size of 0.9 mm weakens the enhancement.