Experimental study of a novel design bi-fluid based photovoltaic thermal (PVT)-assisted heat pump dryer

This study evaluated the performance of a novel design bi-fluid (air and refrigerant)-based photovoltaic thermal assisted heat pump dryer (BfPVTA-HPD), combining a compact bi-fluid PVT using curved directional fins that direct air at different points to the evaporator/waste aluminum material and HP system with a PVT air outlet mounted micro-channel condenser. BfPVTA-HPD was analyzed regarding energy, exergy, and drying characteristics at two different times, in clear and partially cloudy weather conditions. Mint leaves (Mentha piperita L.) were dried to evaluate BfPVTA-HPD's drying capabilities. The average electrical, thermal, and exergy efficiencies of PV and PVT for Exp-1 and Exp-2 varied to 15.97, 16.54%, 18.21, 18.23%, 55.36%, 42.04%, 30.95%, and 25.08 %, respectively. In Exp-1 and Exp-2, respectively, while an increase of 12.32 % and 9.29% in the average electrical efficiency was achieved by using PVT, an average of 3.15 and 2.86 were reached in the coefficient of performance (COP) of the heat pump. The exergy indicators (the improvement potential, sustainable index, and waste exergy ratio) for the Exp-1 are 839.52, 1.39, and 0.82. The exergy indicators for the Exp-2 are 1166.14, 1.30, and 0.84, respectively. The experiment's average mass transfer coefficients were obtained as 1.17 x 10- 8 and 7.75 x 10-9 m/s respectively. The experiment's average effective diffusivity coefficients were obtained as 2.90 x 10-11 and 2.04 x 10- 11 m2/s, respectively. The recommended BfPVTA-HPD can be used as a new model to improve the ecological footprint and green manufacturing. Furthermore, the electricity and heat production required for the sustainability of the drying system in spring and winter can be realized.