Air cooled heat exchangers are used in many technology applications. Compactness, functionality and prize is decision maker for many future customers. Current development of compact heat exchangers is evident. Mostly used technology - expanded copper tube on aluminium fin is fluently changed by all aluminium heat exchangers with sophisticated heat exchange surface. Heating, Ventilating and Air-Conditioning with Refrigeration industry (HVAC-R) uses more and more extrude aluminium profiles as the main structure for all size heat exchangers. Similarly to Automotive industry HVAC-R uses minichannels as the basis of their products. It is not a new technology, it is technology proved through many years use in car industry. It is also true that current well known minichannel technology is not the last step. New designs and production lines are currently developed as well. All these new technologies have one unsolved thing together – how will be the new technologies easily computed through models. Current correlations which were used till now are obsolete, because of system miniaturization mainly. It is not easy to adapt old macro channel correlations on minichannel or microchannels where is not possible to diminish capillarity effects, different flow structures, etc. All these difficulties causes in model changes, software changes or iterative procedures upgrades. It is also evident that a lot of experimental exercises have to be done to examine heat exchanger behaviour ad characteristics. Because of precise computation of minichannel heat exchangers need or its geometry optimization is dissertation theme aimed to compare computation methodologies. PhD thesis is also aimed to check functionality of proposed computation system used simple similarity model. All proposed methods are compared to experimentally measured data and as the outcome of thesis are these data used to develop new computation basis.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:233994 |
| Date | January 2012 |
| Creators | Pavlů, Jaroslav |
| Contributors | Masaryk, Michal, Jaroš, Michal, Pospíšil, Jiří |
| Publisher | Vysoké učení technické v Brně. Fakulta strojního inženýrství |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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