Banca de DEFESA: CAIO VINICIUS PINHEIRO VITAL

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAIO VINICIUS PINHEIRO VITAL
DATE: 19/01/2023
TIME: 14:00
LOCAL: Sessão por Videoconferência. Link da sala: https://meet.google.com/tsy-wyhg-uns
TITLE:

PLASMONIC NANOPARTICLES AND OPTICAL CONCENTRATION LENTICULAR SYSTEM FOR DIRECT ABSORPTION SOLAR COLLECTORS.

KEY WORDS:

Direct Absorption Solar Collector. Nanofluid. Solar Energy.

PAGES: 104
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUMMARY:

The increase in the share of renewable sources in the global energy matrix is a key contribution to reducing greenhouse gas emissions. In this sense, the thermal use of solar energy has the potential to supply heat demand for different processes. Direct absorption solar collectors are devices that convert solar radiation into heat in a working fluid. In particular, colloids of plasmonic nanostructures, presenting the phenomenon of localized surface plasmon resonance, can be used as a working fluid for direct absorption solar collectors. However, the use of these fluids is limited by factors such as colloidal stability, high production cost, and increased pumping power in thermal systems that use them. In this work, proposals are addressed to overcome these obstacles: the use of nanofluids composed of plasmonic nanoparticles of different materials and morphologies in direct absorption solar collectors is investigated. Nanofluids composed of iron-doped gold nanoshells, metallic nitride nanospheres, metallic nanocages, and hybrid nanofluids with metallic nanoellipsoids are explored. The optical properties of the fluids are modeled using Mie Theory and numerical simulations in the COMSOL Multiphysics software. Also, the use of lenticular systems for light concentration in direct absorption collectors is investigated. The thermal modeling of solar collectors is conducted using the Finite Difference Method applied to a two-dimensional heat transfer model. For the lenticular direct absorption collector, ray optics analysis via finite elements in the COMSOL Multiphysics software is also performed. In addition, experimental thermal characterizations of some nanofluids and the lenticular direct absorption collector were carried out. Results show that collectors using the proposed nanostructures perform better than devices with other plasmonic nanostructures, presenting higher energy and exergy efficiencies in a low particle concentration regime. Maximum energy efficiencies were 95% with iron-doped gold nanoshells, 89% with metallic nitride nanoparticles, 90% with metallic nanocages and 90% with hybrid nanofluids of nanoellipsoids.With the lenticular system, collectors with similar energy efficiency and exergy efficiency up to 142% higher than traditional direct absorption collectors are obtained. The proposed approaches reveal that it is possible to obtain high-performance collectors with small amounts of nanofluid in a low-concentration regime.

COMMITTEE MEMBERS:
Externo à Instituição - ALBERT STEVENS REYNA OCAS - UFRPE
Externo ao Programa - 1133622 - ANDERSON STEVENS LEONIDAS GOMES - nullExterna à Instituição - 0 - - nullExterna ao Programa - 1548259 - OLGA DE CASTRO VILELA - nullPresidente - 2199776 - RENATO EVANGELISTA DE ARAUJO