32. Performance Analysis and Parametric Studies of a Bi-fluid Type Photovoltaic/Thermal (PV/T) Solar Collector in Simultaneous Mode Under Tropical Climate Conditions

Performance analysis of a photovoltaic/thermal solar collector with a bi-fluid configuration (air and water) was conducted under real sky conditions in the tropical climate of Perlis, Northern Peninsular Malaysia. In addition to the electricity generated, this type of collector has enabled three different modes of fluid operation: air mode, water mode and simultaneous (bi-fluid) mode. The third mode of fluid of operation is the primary focus in this chapter. This chapter highlights the performance of the collector outdoors, in terms of the experimental and two-dimensional theoretical analysis at steady state. For collector testing under real sky conditions, analyses of the collector for varying sets of mass flow rates under environmental conditions of an average wind speed of 3 m/s and average solar radiation of 700 W/m² were conducted. To obtain suitable data, experiments were conducted for each of the mass flow rates on ten different days of testing. For the simultaneous mode, when air flow rate was fixed at 0.0262 kg/s, at a water mass flow rate that varied from 0.0017 to 0.010 kg/s, the electrical efficiency and total thermal efficiency ranged from 8.13 to 8.60 % and 44.36 to 47.45 % respectively. When the water flow rate was fixed at 0.0066 kg/s, at an air mass flow rate that varied from 0.0092 to 0.0753 kg/s, the efficiencies ranged from 8.10 to 8.56 % and 44.06 to 50.37 % respectively. Theoretical analysis was then conducted and compared with the experimental analysis by comparing the trend of the curves and using mean absolute percentage error (MAPE) analysis. The curves were found to be in good agreement, and the computed MAPE for the fluids’ output temperature was less than 2 %. Parametric studies were then conducted to investigate the performance of the collector with the change in air channel depth and performance with the change in collector length. The feasibility of incorporating two different types of working fluid into the same PV/T solar collector was demonstrated based on the thermal and electrical energy output of the collector under real sky conditions. Therefore, this research will serve as a starting point for further research into a bi-fluid type PV/T solar collector, both experimentally and theoretically.