Theoretical And Experimental Study On CPC Integrated PV/T System

By integrating solar cell modules and solar collectors,solar photovoltaic thermal (PV/T) systems can convert solar energy into both electrical and thermal energy,thus greatly improving the efficiency of solar energy utilization system.Concentrating PV/T systems which adds the concentrators based on the typical PV/T system,can increase the solar flow intensity and improve the thermoelectric output efficiency of the solar cells and collector by focusing sunlight on the solar cells.Currently,the Fresnel,parabolic trough and butterfly collectors are more focused at home and abroad,while research about compound parabolic concentrator (CPC) is seldom studied.A CPC Integrated PV/T system bench is designed and built in this study.PV/T collectors are constituted by laminating polysilicon solar panels and cartridge flat collectors which is then integrated with CPC to form the whole concentrating PV/T systems.The photovoltaic and thermal performances of the system have benn theoretically analyzed and experimentally studied and the results are as follows:(1) With solar radiation intensity over 800W/m2 and the electrical efficiency more than 10% in the lkw bench system,the temperature of output water can reach 45℃ which is able to satisfy the basic water and heating needs.(2) According to the experimental data, in order to ensure the safe operation of the system,obtain higher performance parameters and meet the practical needs,the temperature of output water should be set as 45℃.At that point, the flow of the system is measured as 192L/h.Operation parameters of PID:P=130,I=1,D=0.1。(3) CPC Integrated PV/T Systems can achieve better thermoelectric performances. When daily amount of solar radiation is 17.28MJ/m2,the photovoltaic output of the system is 18.25MJ,average photoelectric efficiency 8.9%,quantity of heat 99.33MJ,average optical heat efficiency 48.6%,the total efficiency of the system 57.5%.(4) Compared with traditional photovoltaic arrays and collectors,CPC Integrated PV/T Systems enjoy advantages in overall performance,technological advancement and economic aspect.(5) Through theoretical simulation study,we have found that the simulation results and experimental results were generally similar,which has verified the design of the experiment bench.When the flow is 210L/h,theoretically simulated optical heat efficiency is 56.6% while the experimental value is 52.5% with error being 7.2%; theoretically simulated photoelectric efficiency is 12.1% while the experimental value is 10.1% with error being 16.5%.Notably,the error of photoelectric efficiency is a little large, therefore the bench need to be further improved in this regard.