Gas film heat transfer as enhancement strategy for phase change materials
In this work, consideration is given to an alternative strategy for phase change materials (PCMs) heat transfer enhancement with particular reference to horizontal plates. In contrast with current approaches in which heat transfer enhancement is pursued either by adapted geometries or acting on the...
| Autores: | , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2019 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositório: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglês |
| OAI Identifier: | oai:upcommons.upc.edu:2117/170818 |
| Acesso em linha: | https://hdl.handle.net/2117/170818 https://dx.doi.org/10.1002/est2.95 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Heat -- Transmission Energy storage PCMs heat transfer enhancement Thermal storage Stationary power Calor -- Transmissió Energia -- Emmagatzematge Àrees temàtiques de la UPC::Energies Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids |
| Resumo: | In this work, consideration is given to an alternative strategy for phase change materials (PCMs) heat transfer enhancement with particular reference to horizontal plates. In contrast with current approaches in which heat transfer enhancement is pursued either by adapted geometries or acting on the thermal conductivity coefficient of a given PCM, here the problem is tackled by preventing the formation and contact of the front of solidification at the wall of the vessel by the deliberate presence of a gas film between the wall and the PCM. Because the presence of such a film, the front of solidification only can attains a certain critical thickness before gravitationally sinks by its own weight and then eliminating the continuous growth of the solid layer with the consequent reduction of conductive heat transfer and power output of the system as the solidification takes place which translates into an enhanced and steady power during the entire solidification process. It is shown that because the critical thickness of the solidified layer before sinks is a few millimeters or less and then smaller than practical gas films, therefore the heat transfer is controlled by the thickness and the thermal conductivity of the film. Additional R&D is required in order to arrive at a reliable practical and safe design |
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