Exergy analysis of a high concentration photovoltaic and thermal system for comprehensive use of heat and electricity

Highlights: • A multiphysics 3-D steady model of a HCPV/T system's plate heat exchanger has been developed. • The performance of the system was evaluated from the perspective of the first law of thermodynamics and exergy. • The calculation formula of exergy efficiency for HCPV/T system is established. By analyzing the temperature distribution cloud image of the solar cell, it was found that the temperature distribution was uneven and there was a large temperature gradient, resulting in reduced effective cell size requiring a dual inlet model. At the same time, simulations and experiments were established, and it was found that the simulation results were consistent with the experimental results. This paper offers the first law of thermodynamics efficiency and exergy analysis of a simple optimized model at different inlet flow, concentration ratios and inlet temperatures. The result shows that while the inlet flow is 0.02–0.06 kg/s, the system runs efficiently, which can provide considerable heat output, and has greater protection for the cell. When the concentration ratio increases, thermodynamic efficiency and exergy efficiency will decrease, but the total output exergy is in an increasing trend and the trend will decrease as the concentration ratio increases. As the temperature of cooling water increases, the thermal and overall exergetic efficiencies will also increase, and when the inlet temperature is 60 °C, the electrical efficiency is still greater than 20%. In practical applications, the quality of thermal energy can be improved by increasing cooling water temperature, broadening the field of application.