resumo
A core shell model has been derived for microstructural design of PCM-based composites with optimized 3-dimensional organization of a conducting phase, and a novel method was developed to process self-assembled core shell composites for thermal regulation or heat storage. The method was based on emulsification of graphite suspensions in melted paraffin yielding a core shell microstructure based on self-organisation of graphite platelets with preferential orientation; this allows remarkable enhancement of thermal conductivity, which increases by at least one order of magnitude for 5 vol% graphite addition. The microstructure of the graphite shell remains stable upon repeated cycling above and below the melting temperature of the paraffin, and shape stabilization is also retained, even without external encapsulation. One confirm that the levels of thermal conductivity of these phase change materials is sufficient for latent heat discharge from relatively large spherical samples to surrounding air. (C) 2014 Elsevier Ltd. All rights reserved.
palavras-chave
LATENT-HEAT STORAGE; ENERGY-STORAGE; GRAPHITE COMPOSITE; CARBON FOAMS; ENHANCEMENT; RELIABILITY; SYSTEM
categoria
Thermodynamics; Energy & Fuels; Engineering; Mechanics
autores
Vitorino, N; Abrantes, JCC; Frade, JR
nossos autores
João Carlos de Castro Abrantes
Professor Adjunto
Jorge Ribeiro Frade
Professor(a) Jubilado(a)
Nuno Miguel Dias Vitorino
Bolseiro de pós-DoutoramentoProjectos
agradecimentos
This work was supported by FCT, Portugal, and European funding (programs COMPETE, QREN and FEDER) under Projects PTDC/CTM-ENE/2073/2012, PEst-C/CTM/LA0011/2013, Operacao NORTE-07-0162-FEDER-000050 and PhD grant SFRH/BD/62598/2009.; The SEM facility was funded by FEDER Funds through QREN - Aviso SAIECT-IEC/2/2010, Operacao NORTE-07-0162-FEDER-000050.; Thermal Analysis Laboratory was funded by FEDER Funds through Programa Operacional Factores de Competitividade - COMPETE and by National Funds through FCT - Fundacao para a Ciencia e a Tecnologia under the project REEQ/515/CTM/2005.