Experimental studies of different operating parameters on the photovoltaic thermal system using a flattened...

The efficiency of the photovoltaic (PV) cell reduces with an increase in solar irradiation. The reduction in the efficiency of the photovoltaic (PV) cell can be attributed to the increase in cell temperature. A novel design of a thermal absorber fabricated by a flat spiral tube is used to remove heat and decrease the cell temperature, thus forming the photovoltaic thermal system (PVTS). Water and titanium oxide (TiO₂) nanofluid (NF) with a concentration ratio of 0.1% are used as the working fluid in the PVTS. The study has been carried out for the mass flow rates (m_f) of 0.05, 0.066, and 0.083 kg/s. The reduction in the cell temperature is obtained to be 5.7 and 11.2 °C due to the cooling effect of water and TiO₂ NF, respectively. The percentage increase in electrical efficiency is 2.93 and 5.28% by cooling using water and TiO₂ NF, respectively. The hourly variation of the performance of the PVTS shows that TiO₂ NF at 0.083 kg/s shows the highest photovoltaic thermal efficiency of 69.2% and thermal and electrical efficiency of 56.45 and 12.75%, respectively. The best coefficient of energy for TiO₂ NF is 1.27 for a m_f of 0.083 kg/s.