Utilização de regeneradores magnetocalóricos em sistema OTEC

• Autor(a) principal: Ignacio, Rene Maria [UNIFESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=2356597; http://repositorio.unifesp.br/handle/11600/46204
• topic: Alternative energy sources; Magnetocaloric effect; OTEC; Magnetism; Technology - simulations; Fontes alternativas de energia; Efeito magnetocalórico; OTEC; Magnetismo; Tecnologia; Simulações

The aggravation of the energy crisis initiated at the beginning of the years 1970 and the necessity of generation of energy in a clean and sustainable way stimulate the research for technologies using renewable sources like OTEC, energy generated by the difference of the temperature between superface and deep waters of the ocean, and Magnetocaloric Effect, generation of heat in magnetocaloric material submitted to a magnetic field. The proposal was to increase the efficiency of an OTEC by raising the temperature of the water collected in the surface of the sea, to be used in the evaporator of the OTEC, making it pass through a warm magnetocaloric regenerator, while submitted to a magnetic field, and reducing the temperature of the water proceeding from the evaporator of the OTEC, to be used in the condenser of the OTEC, making it pass through the same regenerator when it gets cold by leaving the magnetic field. In the fluidodynamic and electromagnetic simulations the model was represented by a gadolinium magnetocaloric regenerator in the form of a 90? sector crown, internal diameter of 7,7 m and external of 8,4 m, 20 m of length, 6.500 pipes with 25 mm diameter, 10 permanent magnets of 3x3x20 m, in NdFeB with BH_max of 35 MGOe. In the fluidodynamic simulation the rise of the temperature of the water collected in the surface of the sea was of 26?C, the liquid power of the OTEC increased in 13%, but the reduction in the temperature of the water was insufficient to be used in the condenser of the OTEC so the need of deep sea water still remains. In the electromagnetic simulation the regenerator reached only 26?C due to the low magnetic field over it. To increase the temperature of the magnetocaloric material it was suggested the research of geometric models associated to materials with a higher magnetocaloric effect. The conclusion was that it is possible to use magnetocaloric regenerators to increase the efficiency of an OTEC, but otimization research is indispensable.