Abstract: Based on numerical simulation,the flow distributions of the ordinary header and three improved headers was studied with PIV, and a series of velocity streamline graphs of different cross sections were obtained.At Re＝6.22×10⁴ the outlet flow distributions of the ordinary header and an improved header, and the effects of flow distribution of three improved headers with different middle-hole-area ratios were compared.The experimental results showed that the perforated plate header configuration could effectively improve the uniformity of fluid flow distribution.Flow maldistribution parameter S_U and the ratio of the maximum velocity to the minimum velocity θ_U of the type C header configuration were minimum.There was an optimum point between flow distribution and the middle-hole-area ratio.

摘要： 在数值模拟的基础上，利用粒子图像测速仪(PIV)对板翅式换热器原始封头A和3种改进的顺排孔板型封头结构(B、C、D)的流场进行了可视化的实验，获得了封头内部不同截面处流场的速度流线分布图.比较了Re＝6.22×10⁴时原始封头A和一种改进型封头B的出口物流分配以及3种不同中孔面积比率的改进型封头对出口物流分配的影响.结果表明：改进型封头结构能有效地改善物流分配的均匀性；C型封头的不均匀参数S_U和最大流速与最小流速之比θ_U最低；流量分布和中孔面积比率之间存在着一个最佳值.