This thesis investigates the refrigerant (R-134a) flow in three minichannels having
different geometries experimentally. During the last 40 years heat transfer in
small scales has been a very attractive research area. Improvements in heat
transfer in the refrigeration applications by means of usage of micro/minichannels
provide significant developments in this area. Also it is known that experimental
studies are very important to constitute a database which is beneficial for new
developments and research. During the two-phase flow experiments conducted
in the minichannels, low mass flow rates and constant wall temperature
approach, which are the conditions in the evaporators of the refrigerator
applications were applied because one of the purposes of this study is to
determine the most ideal minichannel among the tested minichannels for usage
in the evaporator section of the refrigerators. Two-phase flow experiments were
made with refrigerant R134a in the three minichannels having hydraulic
diameters of 1.69, 3.85 and 1.69 mm respectively. As distinct from the others, the
third minichannel has a rough inner surface. Comparison of the experimental
results of the three minichannels was made in terms of forced convection heat
transfer coefficients and pressure drop at constant quality and mass flux values.
As a result of the experiments, the most ideal minichannel among the tested
minichannels was determined for the evaporator applications in the refrigerators.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12614095/index.pdf |
| Date | 01 February 2012 |
| Creators | Agartan, Yigit Ata |
| Contributors | Guvenc Yazicioglu, Almila |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | Access forbidden for 1 year |
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