碩士 / 國立成功大學 / 機械工程研究所 / 83 / There are two parts in this paper,for the first part of this
paper, an induced wind tunnel and air conditionung system were
used to measure the performance on heat transfer and pressure
friction factor for the dry coils and the wet coils of nine
plate-fin and tube heat exchangers with different fin pitch and
tube outside daimeter.The ambient temperature and humidity are
controlled at 25'C and 70%,respectively. Measurements were made
for the air frontal velocity ranging from 0.8 to 6.5 m/s,while
the water inlet temperature and flow rate are maintained at
72'C and 17 L/min for the dry coils and at 7.2'C and 28 L/min
for the wet coils.The experimental results indicated that the
heat transfer coefficient increase with the increase of fin
pitch, and pressure drop for the wet coils was 10% higher than
the dry coils owing to the distrubrance of the vapor boundary
layer by the presence of droplets in the condensate layer.
Colburn j factor for the wet coils is higher than the dry coils.
By comparing with the present experimental data with those of
McQuiston's prediction,it was found that McQuiston's j
predictions were good agreement with the experimental data as
tube diameter is 9.53mm and 12.7mm for the dry coils,other
predictions were mucher lower, and most McQuiston's f
predictions were mucher higher than the experimental data.The
new correlations of j and f factor has been developed. The
second part od this paper is to developed an interactive
comperaided design software for plate finned-tube heat
exchanger with the new correlations.It was written by Quick
BASIC language and can be run in any persional computer.It
could be solved the rating problem and sizing problem friendly
and rapidly.
| Identifer | oai:union.ndltd.org:TW/083NCKU0489006 |
| Date | January 1995 |
| Creators | Sie-Uion Lain, 連士元 |
| 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 | 118 |
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