Due to the high performance of electronic components, the heat generation
is increasing dramatically. Heat dissipation becomes a significant issue in
efficiency promotion and stable operation. Microchannels are of current interest
for use in heat exchangers where very high heat transfer performance is desired.
Microchannels provide high heat transfer coefficients because of their small
hydraulic diameters. In this study, the design and experimental investigation of
fluid flow and heat transfer in a microchannel heat exchanger is conducted. Water
and air are used as the working fluids and flowed through microchannels. The heat
exchanger has been designed with 6 rows of microchannels for water flow and 7
rows of microchannels for forced flow of air. The heights of the microchannels are
4 mm and 10 mm respectively for water and air flows. Microchannels are brazed
to form the heat exchanger. For forced convection cooling with air, a military fan
is used. A constant heat source has been specifically designed for experiments.
Water flow and heat transfer experiments are conducted on the aluminum
microchannel heat exchanger. An experimental method of imposing a constant
heat flux to water prior to the entrance to the microchannel heat exchanger, to
adjust the inlet temperatures is used.
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From the data obtained, the rate of heat transfer, effectiveness and various
other parameters have been computed and the results have been compared with
those from an available commercial heat exchanger. The results indicate that the
heat exchanger performs well and provides 681 W of cooling in a volume 677.6
cm3 while the commercial heat exchanger provides 702.5 W of cooling in a
volume 2507.5 cm3. In addition, air-side Colburn modulus has been obtained with
respect to Reynolds number.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12611856/index.pdf |
| Date | 01 April 2010 |
| Creators | Cetin, Murat |
| Contributors | Yazicioglu, Almila Guvenc |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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