An experimental study of the air-side performance of a novel louver spiral fin-and-tube heat exchanger
Parinya Kiatpachai, Thawatchai Keawkamrop, Lazarus Godson Asirvatham, Mehrdad Mesgarpour, Ahmet Selim Dalkılıç, Ho Seon Ahn, Omid Mahian, Somchai Wongwises
Abstract
We studied the effect of fin patterns on the air-side performance of a novel type of heat exchanger, namely louver spiral fin-and-tube heat exchangers (LSFTHXs). We investigated three types of fin patterns—radial, curved, and mixed-louver spiral fins—and compared their characteristics with plain spiral fin. We fabricated heat exchangers with a crimped aluminum fin base, two rows of steel tubes, and a fin pitch of 8.45 mm. All heat exchangers had both multipass parallel and counter cross-flow arrangements. The average heat transfer rate (Qave), heat transfer coefficient (ho), and pressure drop (ΔP) increased along with frontal air velocity. The louver-spiral fin provided greater Qave and ho than plain-spiral fin by about 9.7–15.6% and 13.4–27.1%, respectively. The j factors (Colburn factors) of louver-spiral fins were greater by approximately 10.4–13.1% (for mixed LSFTHX), 7.7–8.8% (for radial LSFTHX), and 2.1–5.1% (for curved LSFTHX) compared with the plain SFTHXs. Additionally, we found no significant difference in ΔP or f factor (friction factor) between louver-spiral and plain-spiral fins. LSFTHX configurations increased ho and j.