DESIGN AND CONSTRUCTION OF A SYSTEM FOR CONTROLLING THE INLET TEMPERATURE IN SOLAR COLLECTOR TESTING
Crisciele Ferreira dos Santos1; Arno Krenzinger1; Tiago Manea1; Gian Roberto Tirello2
1 Universidade Federal do Rio Grande do Sul; 2 Universidade Regional Integrada
doi:10.20906/CPS/COB-2015-0544
Resumo
Solar collectors are devices that convert solar energy into thermal energy. These devices are widely used in water heating for domestic use. To determine the efficiency of the collectors tests are required, where the temperature at the inlet and outlet of the collector must be measured, as well as other parameters. For the analysis, it should be used the European Standard EN 12975: 2006 that has two test methods: stationary and quasi-dynamic, both requiring tests with different water inlet temperatures in the collector. During the test the water temperature in the collector entry should be kept constant, ie, with less fluctuation possible. The stability of the water inlet temperature is of capital importance during the test since it significantly affects the thermal energy converted by estimated manifold. The objective of this study is to describe how the system was developed to control the water temperature in the collector inlet. To achieve temperature stability, a temperature control system was prepared with two electric heaters that are controlled by a PID controller, flow meter and pt100 sensors for temperature measurement. The system test was carried out for different temperatures and flow rates and the temperature control system comply with the need of provision on the inlet temperature stability to the collector under test. Later this system will be implemented to bench tests of solar collectors at Laboratório de Energia Solar (LABSOL) of the Universidade Federal do Rio Grande do Sul (UFRGS).
Palavras-chave: solar collector; temperature stability; PID controller