Ali Mahdi AZEEZ AZEEZ, Atilla BIYIKOĞLU, Naseer Kareem Kasim AL-SUDANY
Due to its unlimited supply, eco-friendly concept, and ability to harvest energy directly from the sun, solar energy has the greatest potential among all renewable energy sources. Photovoltaic thermal PVT modules combine photovoltaic (PV) modules with solar thermal collectors to produce electricity and heat energy. This study used a practical model of a direct contact PVT that supplies hot water and cools solar cells; experimental and numerical analysis were conducted to evaluate solar cell modules' performance according to Iraqi weather conditions. The numerical study has been done using the ANSYS program to investigate the thermal performance of a direct contact flat plate solar collector using water and water/ nanofluid as a heat transfer medium; the effects of volume flow rates on the PV cell temperature have been studied. The experimental study was carried out in Baghdad in February 2023 at the Iraqi ministry of electricity (Training and Energy Research Office) using the same values of volume flow rate and water as a heat transfer medium for validation. Numerical simulations were conducted at a transient state with an ambient temperature of 20 C, and an input flow rate ranging from 0.5 to 2 L/min with water layer thickness 4 mm, and solar radiation was determined by activating the solar calculator in the program by providing it with the coordinates of the work site in terms of longitude, latitude, and altitude. While in the experimental study, the solar panel with the dimension (2182*1029) mm2 and a maximum power of 465 W was used and a flat plate of aluminum with a thickness 2 mm as a collector was connected to the rear side of the photovoltaic module with a fluid layer thickness 4 mm. The best results obtained through the simulation were used in the experimental study for validation. The numerical results show the maximum PV cell temperature falls from 41.18 C without cooling to 25.1 C by cooling with water when the input flow rate is 2L/min and decreases to 24.3,23.95, and 23.55C when using water/ (1%,2%, and 3% AL2O3) respectively. While the PV cell temperature when the input flow rate (0.5,1, and 1.5 L/min), the decrease in the average cell temperature at these values are less. As a result, PV temperature decreases with increased flow rate since more heat dissipates from the PV as the water flows under the PV. As the inlet flow rate increases, the average cell temperature drops both numerically from (34.64C to 25.8C) and experimentally (from 41.23 C to 29.7C), and the temperature of the output water drops from (32.3 C to 23.9 C). and from (35.7C to 26.5C). An increase in the inlet flow rate reduces the average cell temperature by increasing convectional heat dissipation from the module, and heat is removed faster, lowering the water's temperature as it outlets the flow channel. In the experimental study the PV thermal system's thermal yields. At 10:30 and 11:30 am, the maximum energy output from the solar module is 420 W with water cooling and 373 W without water cooling. The most significant electrical power generation occurs for the PV with water cooling. The power output rises due to PV cooling. (This study is derived from the master's thesis of the first author. ORCID NO: 0009-0004-9068-5070)

Anahtar Kelimeler: Solar Energy, Photovoltaic, Nanofluid, Direct Contact, Electrical Efficiency