Energetic study of a solar combisystem installed in Tunisia

The endeavor of this study is the TRNSYS simulation of the energy long-term performances of solar combisystem used for Tunisian houses. The mainly components of the system are: flat-plate solar collector, heated floor tank (HFT), domestic hot water tank (DHWT), house and an active layer integrated inside the floor heating. A validation of the TRNSYS model was firstly achieved. Then we evaluated the longterm performances of the \u201ccombisystem\u201d by introduction the Typical Meteorological Year data relative to Tunis, Tunisia. The results of the study showed that the annual collected energy, energy load and energy supplied to the active layer were 2940.56, 5369.52 MJ/m\ub2 and 2940.56 MJ/m\ub2 respectively. It is also seen that the annual amount of auxiliary energy represents about 36 % of total annual energy load. An optimization of the \u201ccombisystem\u201d was also achieved. We noted that the \u201ccombisystem\u201d assure an optimal function when we use about 18 m\ub2 of collector area, 400 kg h-1collector mass flow rate, 1350 liters of tank capacity, 1.2 m of tank height and 2140 kg h-1 floor heating\u2019s mass flow rate. The results showed that assuming the previous optimal parameters the chosen solar combisystem provides a stable temperature of domestic hot water about 53\ub0C and a temperature in the array of 20 and 26\ub0C in the interior of the heated house with an average solar fraction of about 84%