Performance analysis of PV/Trombe with water and air heating system: an experimental and theoretical study

This paper studies an improved design of a photovoltaic/Trombe wall (PV-TW) system. It was integrating a PV panel with a serpentine-shaped copper tube as the water heating component and a single pass air channel as the air heating component. In addition to the electricity generated this type of PV-TW system enables to supply both hot air and water, which is increasing the total efficiency per unit area compared to the classical Trombe wall. The use of both fluids (bi-fluid) also creates a more excellent range of thermal applications and offers options in which hot air and water can be utilized depending on the energy needs and demands. In this paper, the design concept of the bi-fluid PV-TW system is emphasized with 1D steady-state energy balance equations for the bi-fluid configuration are developed, validated and used to predict the performance of the bi-fluid PV-TW system for a range of mass flow rates of air and water. Incorporating the DC fan and bi-fluid cooling circuits offered favorable features of the system performance while combining the glass cover in front of the PV cell has a conflicting effect. The maximum thermal and electrical efficiencies for average daily evaluation were 79.89% and 10.69% under 300 liters/day for bi-fluid with DC fan glazed and unglazed PV-TW systems respectively. A well matching between theoretical and the experimental results were achieved, where the maximum discrepancy between them was less 4% for the solar cell temperature.