碩士 / 國立成功大學 / 機械工程研究所 / 83 / The heat transfer performance of an air-cooled heat exchanger
is most heavily dependent on the pattern of fins. To meet the
demand for saving energy and resources today, manufactures of
heat exchangers are trying to enhance efficiency and to reduce
size and weight. For a typical finned-tube exchanger, the
thermal resistance is on the air side. As a result, the heat
transfer surface has been improving for the past few decades.
The convex louver surface is a combination of wavy and louver
fin geometry. Hitachi [1984] uses the convex louver fin
geometry in their commercial fin tube heat exchangers. Despite
the convex-louver finned tube heat exchanger had been exist for
a decade, the thermal hydraulic performance data of the convex-
louver surface are very limited in the open literature. The
only published experimental related to convex-louver geometry
were reported by Hadata et al[1989]. They presented the
performance data for one row heat exchanger. The heat transfer
coefficient of the convex- lover fin is 2.8 times higher then
of the plain fin at the same air velocity and 2.3 times higher
than plain fin geometry. However, since the tested heat
exchangers are only only one row coils, the effect of tube row
and fin pitch are not shown. Therefore, the objective of this
study is to present extensive experimental data on convex
louver fin surface. Totally, nine heat exchangers are tested at
the present study.Experiments were conducted in a forced draft
wind tunnel. The working medium in the tube side is hot water.
During the experiments, the water inlet temperature is held
constant at 60'C ,frontal velocities range from 0.5 to 5 m/s.
| Identifer | oai:union.ndltd.org:TW/083NCKU0489014 |
| Date | January 1995 |
| Creators | Pong-Yuan Chen, 陳鵬遠 |
| Contributors | Jiin-Yuh Jang, 張錦裕 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 102 |
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