Numerical investigation on configuration improvement of a plate-fin heat exchanger with perforated wing-panel header

An improved header configuration with perforated wing panels was proposed to be installed in patefin heat exchangers in order to improve thermal performance. The fluid flow distribution, power consumption, and effectiveness degradation due to the header configuration in conventional and improved headers were calculated and analyzed. The results showed that the fluid flow maldistribution is very serious in conventional headers, where the outlet velocity decreases gradually along the edge of the header, while the perforated wing-panel header configuration can effectively improve the uniformity of the fluid flow distribution, in which the outlet velocity at the center and edge is almost equal. In addition, it was found that when the wing relative height was γ = 0.1, the wing space ratio was β = 0.1, and the wing angle was α = 70°, the comprehensive performance of the improved header is optimum; compared with the conventional header, the flow maldistribution parameter S_V of the optimum header decreases by 62.2%-65.1% and the effectiveness degradation rate Δε decreases by 91.9%-93.0%. The corresponding pumping power P penalty increases by 88.1%-90.0%, while the quantity is very little when compared with the overall pressure drop of the heat exchanger. The conclusions in this paper are of great significance in the optimum design header of plate-fin heat exchangers.