Abstract: To investigate the influence of the arrangement form of tubular heat exchangers on the flow field uniformity characteristics inside the SCR reactor, this study adopts the numerical simulation method to compare and analyze the flow field characteristics under six heat exchanger arrangement forms, including the blank group (without heat exchange tubes), the matrix tube group, the staggered matrix tube group, the cross arrangement tube group, the transversely fully distributed tube group, as well as the combined scheme of matrix tube group and the flow distribution plate. Based on the Fluent software, the flow field inside the reactor is simulated. Taking the mass uniformity index of the catalyst inlet section (100mm above the catalyst surface) as the evaluation index, combined with the vortex structure visualization analysis based on the Q-criterion in Tecplot software, the causes of flow field inhomogeneity are revealed. The results show that the uniformity index of the blank group is 0.872; the uniformity indexes of the matrix tube group, staggered and cross arrangement schemes decrease to the range of 0.831 to 0.853; the uniformity index of the transversely fully distributed tube group is 0.892; while the combined scheme of matrix tube group and flow distribution plate achieves the optimal uniformity index of 0.946. The study confirms that it is difficult to achieve efficient flow equalization merely by adjusting the structure of heat exchange tubes, and it is necessary to coordinate with flow distribution devices. Considering the construction feasibility and maintenance space requirements comprehensively, the scheme of transversely fully distributed tube group - flow distribution plate is the optimal engineering solution.
