Identification of the dynamic model of the water outlet temperature of a heat pump operating with CO2 and a solar evaporator
Carlos Eduardo Castilla Alvarez1; Hugo Sgarbi Campos1; Luiz Machado1; Antônio Augusto Torres Maia1; Ricardo Nicolau Nassar Koury2
1 Universidade Federal de Minas Gerais; 2 niversidade Federal de Minas Gerais
doi:10.20906/CPS/COB-2015-1691
Resumo
The global growing concern about the environmental impact has led to an increase in the interest of renewable and more efficient energy sources. In this context, the use of heat pumps for domestic water heating has attracted attention. This work presents the dynamic model identification of the water outlet temperature, of a heat pump with a direct expansion solar evaporator. This system was designed for residential water heating and uses CO2 as refrigerant fluid. The developed model was based on experimental tests and the system dynamic response was obtained through step disturbances in the water flow rate. The model system identification was performed employing six different methods suggested by different authors. The results were evaluated by quantitative techniques that allowed selecting the best identification method. By using the methods presented in this paper, it was possible to obtain a model with a similitude percentage, when compared to the experimental data, of over 80%.
Palavras-chave: Heat pump; system identification; water temperature