Study of improvements on flow maldistribution of double tube-passes shell-and-tube heat exchanger with rectangular header

In this paper, a novel and simple method was proposed to improve the flow maldistribution in the rectangular header of the small and compact DTP-STHXs. The numerical simulation was carried out to investigate and evaluate the performance of flow distribution based on experiment. The results showed that the flow distribution of the second tube-pass with conventional header configuration was uniform enough to use in practice. Nevertheless, the flow distribution of the first tube-pass was seriously uneven with Es = 0.157 and Rv = 2.21. The maximum absolute flow deviation Ei relative to the average flow rate was up to 42.1%. In addition to the first row tubes, the flow distribution of the rest of tubes has been improved dramatically after using the novel header configuration. Two approaches were further proposed to optimize it. Eventually, 90% of tubes within 10% flow deviation was obtained by the optimal header configuration (configuration B with θ = 50°) with Es = 0.068 and Rv = 1.28. Compared to the conventional header configuration, the standard flow deviation Es and the ratio Rv decreased by 56.7% and 42.1%, respectively.