Numerical analysis of the effect of the evaporator inlet-outlet position on the PV-T performance

Abstract

The increase in global energy consumption and carbon dioxide emissions increase the interest in renewable energy sources. Solar energy is at the forefront of renewable energy sources, and the decrease in cell efficiency due to various reasons during operation is an obstacle to this technology. Increasing the temperature of photovoltaic cells during operation causes a decrease in cell efficiency. Control of photovoltaic cells temperature is crucial in terms of both prolonging the economic life of the cells and increasing the efficiency of the system. The effect of the evaporator inlet and outlet position of the fluid on the heat transfer is known, but this effect was not examined in the studies carried out to increase the efficiency of the PV-T (photovoltaic–thermal) system. In the current study, the system efficiency parameters and COP (coefficient of performance) values of a PV-T evaporator cooled by forced air circulation were investigated by CFD (computational fluid dynamics) analysis. The analyzes were carried out in a single array for three different flow rates (0.0125 kg/s, 0.0250 kg/s, 0.0500 kg/s) and nine different evaporator inlet-outlet positions (CC, CL, CR, RC, RL, RR, LC, LL, LR), constant radiation of 1000 W/m^2. It was determined that there is a total efficiency difference of over 20% and an overall COP difference of over 25% between the best and worst inlet-outlet positions. The highest total and thermal efficiency were obtained for the RR condition, and the highest electrical efficiency was obtained for the LR condition but in the long-term, the highest efficiency can be achieved with the LC design. In the study also the highest COP values were calculated for the CL condition and the worst COP values for the RR condition.