Phase change materials: energetic analysis for Brazilian territory

• Autor(a) principal: Pons, Vinicius
• Data de Publicação: 2017
• Outros Autores: Stanescu, George
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: PARC (Campinas)
• Texto Completo: https://periodicos.sbu.unicamp.br/ojs/index.php/parc/article/view/8650228
• topic: Energy efficiency. Thermal comfort. PCM. Phase change materials; Eficiência energética. Conforto térmico. PCM. Materiais com mudança de fase.

The potential of reducing electrical energy consumption to maintain thermal comfort in an office with an area of 40 m² was evaluated for the eight bioclimatic zones defined according to the Brazilian norm NBR 15.220-2005. A layer of phase change material (PCM) of natural organic origin was employed on the outer wall. Three strategies for the thermal comfort maintenance were considered: (1) heat pump running according to an inverted Carnot cycle with constant coefficient of performance; (2) strategy 1 heat pump but always prioritizing the ventilation with external air when outside temperature is beneficial to indoor thermal control; (3) ventilation as in strategy 2 and maximum optimization of the heat pump used to maintain the temperature in the defined range. The temperature range 18°C-24°C was defined as thermal comfort and PCM was a mixture of capric acid and dodecyl alcohol with melting temperature of 26.5°C. In strategy 1, PCM reduced 4.28% electrical energy consumption for Santa Maria, state of Rio Grande do Sul, while with strategy 2, the reduction was 13.33%. For Curitiba, strategy 2 reduced 9.47%. The results for strategy 3 for the same city shows that the use of PCM reduces 20.18% of electrical energy consumption. Simulation using the third strategy made possible a reduction around 90% of electrical energy. It was observed in all the cases studied that the solar exergy has the potential of generating enough energy to maintain the internal temperature in the range of comfort. It is clear the need for technological advancement so that this transformation of exergy into electrical energy happens without so much energy loss. This work has qualified these data in a way to better understand their representativeness.