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针对椭圆管矩形翅片间的空气流动特性,将应用于直接空冷电站椭圆管矩形翅片的几何中心相对于椭圆管的几何中心偏置。针对不同偏心距离x,以及不同入口风速u,得到空气侧对流换热系数h和压差p随u的变化规律。模拟结果表明翅片的偏置会对着空气侧的流动与换热产生不同影响:翅片向前偏置,低速尾流区对翅片表面换热的影响减小,空气侧总的表面传热系数h增加,且向前偏心距离△x越大,h越大;翅片向后偏置,低速尾流区造成翅片表面局部换热的恶化,以及压力损失的增加。利用PEC对低速尾流区对矩形翅片椭圆管空气侧的换热与流动的综合影响进行了比较。
In view of the air flow characteristics between the elliptical rectangular fins, the geometrical center of elliptical tube rectangular fin applied to the direct air-cooled power station is offset with respect to the geometric center of the elliptical tube. For different eccentric distance x, and different inlet wind speed u, get the change rule of air side convective heat transfer coefficient h and pressure difference p with u. The simulation results show that the biasing of fins has different effects on the flow and heat transfer on the air side: the fins are biased forward, the influence of the low-velocity wake area on the fin surface heat transfer is reduced, The heat coefficient h increases, and the forward eccentricity distance Δx is larger, the h is larger; the fins are biased backwards, the deterioration of local heat transfer on the surface of the fins and the increase of pressure loss caused by the low-speed wake area. The effect of PEC on the heat transfer and flow at the air side of the elliptical tube with rectangular fins at low velocity wakes was compared.