Sensitivity analysis of velocity field influence on condensers’ performance and parallel circuit design based on actual air velocity distribution

Currently, most integral simulations of condensers are based on the assumption of uniform intake air, which differs from real scenarios and leads to imprecise circuit designs. To obtain the actual air velocity distribution and reflect its impacts in the model, a comprehensive methodological system is established in this study. The implementation involves employing the porous media model to simulate air velocity distribution and utilizing the results as the air inlet condition of the distributed parameter model to achieve an integral simulation of condensers. The results indicate that the air velocity distribution is significantly non-uniform. The distribution of air velocity has a limited impact on the performance of single-row tube condenser, but has a significant effect on double-row tube condenser. Minimizing the discrepancy in the positioning of each sub-flow circuit and arranging tubes with large temperature differences in the high air velocity area can enhance heat transfer performance, the “z"-shaped double-tube parallel circuit designed by these theories can continue to improve the heat transfer performance by 2.8 % compared to the single-tube serial circuit with countercurrent arrangement within the accuracy limits of the simulations, and marking a 43.5 % improvement compared to the conventional zigzag-shaped single-tube serial circuit.