Comparative analysis of a passive system with an active water heating system using vacuum glass tubes solar collector
Juan Diego Naranjo Toro1; Crissiane Alves Ancines1; Crisciele Ferreira dos Santos1; Arno Krenzinger1
1 UFRGS
doi:10.20906/CPS/COB-2015-0476
Resumo
The use of heat generation systems through sustainable energy is becoming important at present time. Solar systems of water heating is a form of clean energy production, and is already part of the Brazilian energy matrix. Beyond the environmental benefits, the use of such systems brings economic benefits to the country and especially those who use them, sparing the use of other energy sources for heating water. In Brazil, the solar water heating is carried out mainly by flat solar collectors, which is a widely known technology because it is produced in the country at low prices. There is another technology that is being spread nationally, the evacuated solar collectors, that are being imported and sold at the most competitive prices in the domestic market. Therefore, it's necessary to understand these systems and their operation to avoid errors in its installation and optimize their operation. In this work, it is accomplishing a comparative analysis of a solar water heating system composed by a water-in-glass evacuated tube solar collector working in forced circulation with the same system working in thermosyphon circulation. This comparison was performed by determining the annual energy that the system can produce for each type of circulation, which was calculated based on the ISO 9459-2 standard and the climatic data of Porto Alegre city, state of the Rio Grande do Sul. A testing bench was mounted, with sensors and measuring instruments which were calibrated before use. To perform these measures, the results show that the system with thermosyphon circulation produces more annual energy than the forced circulation system where the water temperature stratification in the thermal reservoir was lower.
Palavras-chave: solar collector; vacuum tube; thermosyphon circulation; forced circulation