Parametric Analysis of a Novel Photovoltaic/Thermal System Using Amorphous Silicon Cells and Micro-Channel Loop Heat Pipes
Xiao Ren, Jing Li, Xudong Zhao, Jingyu Cao, Gang Pei, Jie Ji
Abstract
Photovoltaic/thermal (PV/T) systems are taking up an increasing market share owing to a high overall solar energy efficiency. An innovative PV/T system that combines amorphous silicon cells and micro-channel loop heat pipes is proposed in this paper. It can overcome problems of large thermal stress at fluctuating temperature and frosting in winter which exist in conventional PV/Ts using crystalline silicon cells and copper tube heat exchangers. A distributed parameter model is built and experimental validation on heat transfer and electricity generation is conducted. The parametric influences of thickness of air interlayer, cover factor, number of MCHPs, area of condenser are investigated. The results indicate that the overall energy efficiency increases from 22.30% to 47.61% as the thickness of air interlayer rises from 0 to 15 mm. A number of MCHPs of 8–14 and length of condenser of 4–6 m are recommended for the sake of cost-effectiveness, and the corresponding thermal and electrical efficiencies are about 47% and 6%. The proposed PV/T system can efficiently harness solar heat with a minor impact on electricity output and has significant potential in the medium temperature applications.