Escoamento Multifásico em Microcanais: Estudo para aplicação a um sistema de refrigeração de painéis fotovoltaicos de alta concentração

06/29/2022

The present thesis focused on the characterization of a two-phase flow in microchannels, for application in a cooling system for high concentration photovoltaic solar panels. The liquid flowed over a stainless-steel foil, heated by Joule effect, in order to simulate the heating caused on a photovoltaic cell when it’s exposed to solar radiation. Five microchannels with different widths were tested, as well as six heat fluxes and four volumetric flow rates and the tests were divided into two rounds. On the first one, the effects of the volumetric flow rate and of the six heat fluxes were studied, keeping the same channel. On the second round, four different channels were used, to study the influence of the hydraulic diameter on the flow, and three heat fluxes were tested. Through the two rounds of experiments, it was sought to understand the bubble dynamics, depending on the conditions applied to the flow, and to identify the instabilities that are, characteristically, found in two phase flows in microchannels, trying to find possible causes for them. At the end of the two rounds of experiments, it was possible to establish relations between the applied variables, the obtained values of pressure and temperature, and the observed flow phenomena. It was also possible to identity paths to follow in future works, in order to continue the studies for the maximization of the efficiency of cooling devices with two phase flow microchannels.

Authors in the community:

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  I

  Iva Andrea Alvarinho Gonçalves

  ist425565

Supervisors of this institution:

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  A

  António Luís Nobre Moreira

  ist12089

mechanical-engineering - Mechanical engineering

por - Portuguese

Instituto Superior Técnico