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COMPUTING SOFTWARE AND METHODOLOGY DEVELOPMENT FOR REFRIGERATION MINICHANNEL CONDENSER EVALUATION
Pavlů, Jaroslav ; Masaryk, Michal (referee) ; Jaroš, Michal (referee) ; Pospíšil, Jiří (advisor)
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.
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Opportunities for 3D printing in the process industry
Haltmar, Jakub ; Jegla, Zdeněk (referee) ; Babička Fialová, Dominika (advisor)
This bachelor thesis deals with the possibilities of using additive technologies in the process industry, especially in the field of heat exchangers (heat sinks), membrane distillation and structured packing. In the first part, the thesis provides an overview of the materials and additive technologies used in these process units. The next part is devoted to specific examples of the use of 3D printing in the process applications and their comparison with conventional manufacturing technologies in the world. Furthermore, an overview of supported projects according to the Research, Development and Innovation Information System projects and the market situation in the Czech Republic is outlined. Recommendations for the development of additive manufacturing in the process industry are proposed in the discussion. In the addressed area, process improvements (efficiency, performance or completely new applications) are most often achieved due to the ability of additive manufacturing to produce complex geometries increasing the functional area while maintaining built-up dimensions and materials specific to the process industry.
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COMPUTING SOFTWARE AND METHODOLOGY DEVELOPMENT FOR REFRIGERATION MINICHANNEL CONDENSER EVALUATION
Pavlů, Jaroslav ; Masaryk, Michal (referee) ; Jaroš, Michal (referee) ; Pospíšil, Jiří (advisor)
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.
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Solution of parameters of compressible viscous fluid flow through a minichannel
Hála, Jindřich ; Šafařík, Pavel ; Luxa, Martin
In this paper the results of the experiment of the choked air flow through channel with characteristic dimensions: height 2mm, width 100mm, length 100mm will be presented. On the bases of the both pneumatic and optical measurements the development of the flow properties along the channel and the influence of the dissipative processes will be described. The results of the experiment will be compared to the theoretical results and to the results of the numerical simulation. At the end the comparison will be thoroughly discussed.
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Numerical and Experimental Studies of The Flow Through Narrow GAP
Hála, Jindřich ; Luxa, Martin
The flow in channels with characteristic dimension of the order of millimetres is of high importance for determination of losses of the devices such as small turbines, screw-type compressors and for investigation of the tip leakage flow. Since most of the contemporary studies deal with the micro or nano flows, the purpose of this work is to provide a reliable experimental data and to explore the possibilities of the numerical simulations of the present flow
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