Numerical investigation on electrical and thermal performance of photovoltaic thermal system in Bangladesh

Abstract

In this thesis, a three-dimensional numerical model of a photovoltaic thermal (PVT) system is considered and solved using the finite element method. Numerical simulation is used to explore the impact of solar irradiation on the thermal energy and electrical power and efficiency of PVT systems. Water is considered as heat transferring fluid. The solar irradiation, inlet fluid volume flow rate, ambient temperature, and partial shading are all chosen in the range of (200 - 500 W/m2), (30 - 180 L/h), (10 - 37°C) and (0 - 30%), accordingly based on the weather condition of Bangladesh. The effects of irradiation, fluid flow rate, ambient temperature, and partial shading on solar cell temperature, outlet fluid temperature, electrical power, thermal energy, electrical efficiency, thermal efficiency, and overall efficiency of the considered PVT system are investigated. It is observed from the results that, for the increases of every 100 W/m2 solar irradiation, the cell and outlet temperature, electrical and thermal energy increase approximately 2.17oC and 0.54oC, 20.7 W and 113.3 W respectively, and the electrical, thermal, and overall efficiencies decrease about 0.17%, 0.67%, and 0.83%. The cell temperature and outlet fluid temperature decrease approximately 0.6°C and 0.83oC, respectively; electrical and thermal energy increase about 0.30 W and 3.07 W respectively, and the electrical, thermal, and overall efficiencies increase about 0.04%, 0.4%, and 0.44% for the increases of every 10 L/h fluid flow rate. For every 10°C increments of ambient temperature solar cell temperature and outlet temperature increase 1.7°C and 0.05oC, electrical energy decreases to 0.9W and thermal energy increase to 9.89W, and the electrical efficiencyreduced about 0.1%. Solar cell temperature, outlet fluid temperature, electrical and thermal energy decrease by 0.4℃, 0.06°C, 10.42 W and 12.67 W and the electrical, thermal and overall efficiencies decrease about 1.33%, 1.67% and 3%for each 10% shading conditions of the PVT system.