水流量对PV/T系统效率、(火用)能及环境效益的影响

Influences of flow rate on PV/T system efficiency,exergy and environmental benefit

搭建了以水为冷却工质的PV/T系统装置,利用卤钨灯模拟太阳辐射进行了实验研究,从系统效率、(火用)能和环境效益3个方面探讨了冷却水流量对PV/T系统性能的影响。实验结果表明:当冷却水流量为20~100 L/h时,与普通PV系统相比,PV/T系统中PV板的温度降低了9.6~13.5℃,电效率增加了0.78%~1.09%;冷却水流量每增加10 L/h,电效率提高0.039%;热效应增加47.32%~62.63%,系统综合效率大幅提升。冷却水为层流时,系统热(火用)随流量增加而减小;冷却水为湍流时,热(火用)随流量的增加而增加,系统电(火用)随流量的增加而单调递增;当冷却水流量为40 L/h时,系统(火用)效率最低。PV/T系统的电能产量、CO_(2)减排量和碳排放费用减少量比普通PV系统增加了5.6%~7.8%,系统性能和环境经济性得到明显提升。

A PV/T system device with water as its cooling medium was built and experimented with a halogen tungsten lamp for simulating solar radiation.The influence of cooling water flow rate on the performance of PV/T system was discussed from three perspectives:system efficiency,exergy and environmental benefit.The experimental results show that when the cooling water flow rate is 20~100 L/h,the PV panel temperature of the PV/T system decreases by 9.6~13.5℃and the electrical efficiency increases by 0.78%~1.09%compared with common PV system.The electrical efficiency is increased by 0.039%for every 10 L/h increase of the cooling water flow rate.Because of the increase of 47.31%~62.63%in thermal efficiency,the comprehensive efficiency of the PV/T system is greatly improved.For the laminar flow of cooling water,the thermal exergy of the PV/T system decreases with the increased flow rate;and in case of turbulent flow,the thermal exergy goes up with the increase in flow rate.Nevertheless,the system electrical exergy monotonically increases with the increased flow rate.When the cooling water flow rate is 40 L/h,exergy efficiency of the system is the lowest.Compared with common PV systems,the power production,CO_(2)emission reduction and carbon emission cost reduction of the PV/T system all increase by 5.6%~7.9%,and the system performance and environmental economy are significantly improved.