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http://dx.doi.org/10.6110/KJACR.2017.29.4.149

An Experimental Study on the Effect of the Air Temperature on the Air-Side Heat-Transfer Coefficient and the Friction Factor of a Fin-and-Tube Heat Exchanger  

Kim, Nae-Hyun (Division of Mechanical System Engineering, Incheon National University)
Cho, Honggi (Digital Appliance Business, Samsung Electronics)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.29, no.4, 2017 , pp. 149-158 More about this Journal
Abstract
In general, the air-side j and f factors of evaporators or condensers are obtained through single-design tests performed under air-dry and wet-bulb temperatures. Considering that the indoor or outdoor air temperatures vary significantly during the operation of an air conditioner, it is necessary to confirm that the experimentally-obtained j and f factors are widely applicable under variable air conditions. In this study, a series of tests were conducted on a two-row slit-finned heat exchanger to confirm the applicability. The results showed that, for the dry-surface condition, the changes of the tube-side water temperature, water-flow rate, and air temperature had virtually no effect on the air-side j and f factors. For the wet condition, however, the f factor was significantly affected by these changes; contrarily, the j factor is relatively independent regarding this change. The formulation of the possible reasoning is in consideration of the condensation behavior underneath the tube. The wet-surface j and f factors are larger than those of the dry surface, with a larger amount for the f factor.
Keywords
Air-side performance; Fin-and-tube heat exchanger; Heat transfer coefficient; Friction factor;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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