Investigation of microchannels heat exchangers for condersers için kapak resmi
Investigation of microchannels heat exchangers for condersers
Başlık:
Investigation of microchannels heat exchangers for condersers
Yazar:
Sevencan, Furkan Tuğberk, author.
Fiziksel Tanımlama:
ix, 52 leaves: color illustrations, charts;+ 1 computer laser optical disc.
Özet:
There are limited types of condenser types/designs in the market although there are many distinct heat exchangers available. One reason is related to the complexity of the phase-change mechanism and how it is affected by the geometric parameters of the heat exchanger. Technological requirements force the size of any component to become smaller and condensers are no exception for this trend. However, there is a limit for scaling down the current condensers, and their compactness cannot be decreased due to their serpentine design. The transition from serpentine designs to parallel microchannels is promising as the required coolant volume would decrease significantly for the same cooling due to enhanced heat exchange surface area. However, parallel channel designs are challenging to implement due to irregularities in pressure distribution which would yield phase change and condensation temperature significantly. In the present thesis, a microchannel heat exchanger was selected and the imperfections related to the pressure distribution irregularities were progressively developed numerically. Geometrical parameters were optimized to eliminate the flow maldistribution resulted from nonhomogeneous pressure distribution in the condenser. The effects of header shape (from rectangular to tapered) on flow uniformity are not dramatic. Then, manifold channels were relocated with given protrusion depths which were optimized using an iterative approach. Relocating the channels enables the pressure uniformity. Finally, the condensation behavior of the design developed with the aim of enabling uniform flow resistance was documented. Under the given operational conditions, three different height channel design is 100% condensed R410a from the vapor phase into the liquid phase. A and B design were condensed the refrigerant fluid in a low Reynolds number meanwhile, C design was condensed in a high range of Reynold number. All in all, effects of maldistribution on flow regime were tried to be eliminated with new geometric design approaches and condensation effect in new geometries was able to be seen 100% at low flow rates. Keywords: Channel Protrusion Depths, Condensation Effect, Flow Irregularities, Maldistribution, Microchannel Heat Exchangers.
Konu Başlığı:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology:Energy Engineering.

İzmir Institute of Technology:Energy Engineering. --Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
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