Flow distributions of header configurations in plate-fin heat exchangers with particle image velocimetry (PIV)

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.