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.

摘要

由于整体太阳能效率高，光伏/热 (PV/T) 系统正在占据越来越大的市场份额。本文提出了一种结合非晶硅电池和微通道回路热管的创新PV/T系统。克服了传统PV/T采用晶硅电池和铜管换热器存在的温差大、冬季结霜等问题。建立了分布式参数模型，并进行了传热和发电的实验验证。研究了空气夹层厚度、覆盖系数、MCHP数量、冷凝器面积等参数的影响。结果表明，随着空气夹层厚度从 0 增加到 15 mm，整体能源效率从 22.30% 增加到 47.61%。考虑到成本效益，建议使用8-14个MCHP和4-6 m的冷凝器长度，相应的热效率和电效率约为47%和6%。所提出的 PV/T 系统可以有效地利用太阳能热，对电力输出的影响很小，并且在中温应用中具有巨大的潜力。