Airside heat transfer and pressure drop of louver-finned parallel flow heat exchanger having a drainage channel

Abstract

Conventional louver fins have an inherent problem of condensate drainage. In this study, a newly developed louver fin is introduced. The louver fin has downstream a drainage channel. The dry and the wet surface heat transfer and pressure drop characteristics of the new sample were investigated, and the results were compared with those of the conventional sample. Compared to the conventional sample, superior wet surface heat transfer and pressure drop characteristics were obtained. The j factors of the new sample were 40% larger, and the f factors were 9% smaller. In addition, the wet j and f factors were not much different from the dry ones, which imply that excellent condensate drainage is possible for the new fin. Under dry condition, however, poor heat transfer and pressure drop characteristics were obtained. The j factors of the conventional sample were 81% larger, and the f factors were 14% smaller. Allocation of the fin surface to flat (not enhanced) drainage channel for the new fin may be responsible. Under wet condition, j/f 1/3 of the new sample was 45% larger than that of the conventional sample. Under dry condition, however, j/f 1/3 of the conventional sample was 91% larger.

Airside heat transfer and pressure drop of an aluminum heat exchanger having a new louver fin with leading edge extension

“…Fig. 3 shows that geometric pattern of the present leading edge extension fin and that of Kim and Cho's (2018) trailing edge extension fin is entirely different. As discussed, main design focus of the present fin was frosting, and thus a geometry, which was expected to mitigate a frost build-up was preferred.…”

“…Also shown in Fig. 3 is a sketch of the trailing edge extension fin by Kim and Cho (2018). An asymmetric louver pattern with 7 louvers at upstream and 9 louvers at downstream is shown.…”

“…Recently, Kim and Cho (2018) introduced a different louver fin configuration, where flat extension was made at the trailing edge. Results showed that, under wet condition, j factor was 40% higher, and f factor was 9% lower compared with those of the conventional louver sample.…”

“…No frosting data were reported. Considering that leading edge extension is preferred for frosting application, Kim and Cho's (2018) fin appears to be limited to dehumidification. In this study, a new fin having an extension at the leading edge is proposed, with frosting application in mind.…”

“…Thus, in this study, a sample made of leading edge extension fin was tested under dry and wet condition. and the results are compared with those of a conventional fin and the trailing edge extension fin by Kim and Cho (2018).…”