弧线管微粒污垢特性的实验研究

微粒污垢的沉积造成换热面流动阻力增大，传热效率降低，腐蚀加剧。文中通过不同流速和微粒浓度下微粒污垢的加速实验，得到了弧线管微粒污垢渐近热阻值和诱导期；同时，用数值方法模拟了弧线管的内部流场和壁面剪切力。结果表明：弧线管微粒污垢的渐近热阻值和诱导期与微粒浓度和流速有关，流速增大、微粒浓度降低，其诱导期延长，渐近污垢热阻减小。而且，在清洁状态、析晶污垢和微粒污垢状态下，弧线管比对应光管都具有良好的传热和阻垢性能，其主要原因是由于弧线管内部流场和壁面剪切力周期性变化所引起的。

Experimental Investigation on the Particulate Fouling Characteristics of Arc Line Tube

The deposits of particulate fouling on heat transfer surfaces create a barrier to heat transfer, increase pressure drop and promote corrosion of material. The induction periods and particulate fouling asymptotic resistances of arc line tube were obtained by comparative experiment under various particulate concentration and liquid velocity. The flow field and shear stress in the arc line tube were numerically simulated and analyzed. The results show that the particulate concentration and the liquid velocity have important effect on the induction period and the asymptotic resistance, high liquid velocity and low particulate concentration may induce longer induce period and smaller asymptotic fouling resistances. Moreover, either clean condition or fouling condition, the arc line tube has better heat transfer performance and anti-fouling ability than its corresponding plain tube, the periodic change of flow field and shear stress in the arc line tube may be the primary reason.