Optimizing structure of photovoltaic thermal solar air heaters with baffles and hole plates
Ziye Song, Yibing Xue, Yougui Feng
Abstract
Based on previous research, a mathematical model of photovoltaic thermal solar air heaters with baffles and hole plates (PVTSAH-B) was proposed to analyze the influence of the opening ratio on the flow and heat transfer characteristics of PVTSAH-B and to further improve its performance. The results showed that the air velocity and temperature distributions were affected by the opening ratio of hole plates. The vortex zones in PVTSAH-B could be broken by air jet flow when the opening ratio of hole plates was less than 0.4. The PV modular surface temperature and the area of the high-temperature zones were decreased with the decreasing of the opening ratio of hole plates. Lowering the opening ratio of hole plates could increase the thermal and power efficiency. However, the fan energy consumption increased due to the decrease in the opening ratio of hole plates increasing the pressure loss. Therefore, the effective power efficiency decreased. 0.4 opening ratio of hole plates recorded the highest performance of PVTSAH-B. Meanwhile, the maximum values of the effective power efficiency, thermal efficiency and the total efficiency were 0.129, 0.567 and 0.696 respectively, which were 5.97%, 12.30% and 11.07%, higher than the opening ratio 1.0, respectively.