Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

In this paper, the application of phase change materials (PCM) in free-cooling systems is studied. Free-cooling is understood as a means to store outdoors coolness during the night, to supply indoors cooling during the day. The use of PCMs is suitable because of the small temperature difference between day indoors and night outdoors. An installation that allows testing the performance of PCMs in such systems was designed and constructed. The main influence parameters like ratio of energy/volume in the encapsulates, load/unload rate of the storage, and cost of the installation were determined, and experiments were performed following the design of experiments strategy. The statistical analysis showed that the effects with significant influence in the solidification process are the thickness of the encapsulation, the inlet temperature of the air, the air flow, and the interaction thickness×temperature. For the melting process the same holds, but the inlet air temperature had a higher influence than the thickness of the encapsulation. With the empirical model developed in this work, a real free-cooling system was designed and economically evaluated.

Free-cooling of buildings with phase change materials

A comparative study of thermal behaviour of a horizontal and vertical shell-and-tube energy storage using phase change materials

Improvement of a thermal energy storage using plates with paraffin–graphite composite

PCM integrated to external building walls: An optimization study on maximum activation of latent heat

Experimentally validated two dimensional numerical model for the solidification of PCM along a horizontal long tube

This paper presents the results of a numerical parametric study of the solidification of a phase change material (PCM) around a cylinder carrying a heat-transfer fluid (HTF) inside. A pure conduction model is used for the PCM and tube wall, the finite volume method is used together with the interface immobilization technique for treating the phase-change process. The convection problem inside the tube is solved by an energy balance with a Nusselt number value, obtained from the steady-state values for constant wall heat-flux conditions. The effects of the HTF entry temperature, the initial PCM temperature and the thermal conductivity of the tube material on the evolution of the solidification front are studied. Results for the temperature distribution during the process, phase-change interface velocity and thermal energy stored in the system are also presented.

Parametric study of solidification of PCM around a cylinder for ice-bank applications

A numerical model is presented for the solution of the solidification problem of a phase-change material (PCM) in the annular region around a convectively cooled cylinder. An existing formulation, using the interface immobilization technique and the finite volume method, is applied and extended for the phase-change problem coupled with heat transfer in the tube wall and fluid. The predicted values are compared with available numerical and experimental results with good agreement. Some aspects of the model are discussed, such as the discretization schemes for the pseudoconvective terms that arise from the formulation and the evaluation of Nusselt number in the fluid.

Modeling and solution of the solidification problem of PCM around a cold cylinder

O processo de solidificacao de um material de mudanca de fase em regiao anular ao redor de um cilindro resfriado pela passagem de um fluido em seu interior e estudado numericamente com vistas a aplicacao em sistemas de armazenamento de calor latente. A solucao do problema de mudanca de fase e feita utilizando a tecnica de imobilizacao de fronteira, onde aplica-se uma transformacao de coordenadas, de maneira que no novo sistema a fronteira movel e irregular seja fixa e paralela as demais. A conducao de calor no material de mudanca de fase e acoplada a conducao na parede do cilindro e a conveccao no interior deste. O metodo de volumes finitos e utilizado para a discretizacao das equacoes do modelo matematico que sao em seguida resolvidas computacionalmente. Sao analisados aspectos relativos a implementacao da tecnica de imobilizacao, como o surgimento de termos pseudo-convectivos e pesudo-anisotropicos por consequencia da mudanca de variaveis. Tambem sao estudados aspectos relacionados com o acoplamento da conducao de calor no cilindro e no material de mudanca de fase e a conveccao no fluido refrigerante. Sao apresentadas comparacoes com outros trabalhos da literatura e um conjunto de resultados para o caso de agua como material de mudanca de fase 
Abstract

http://repositorio.unicamp.br/jspui/bitstream/REPOSIP/263442/1/Jesus_AntonioBatistade_M.pdf

Antonio Batista de Jesus

Papers

Experimentally validated two dimensional numerical model for the solidification of PCM along a horizontal long tube

Parametric study of solidification of PCM around a cylinder for ice-bank applications

Modeling and solution of the solidification problem of PCM around a cold cylinder

Estudo numerico da solidificação em geometria anular