The Study Of Heat-pipe Concentration Solar Photovoltaic-thermal System

Nowadays, devices intended for using solar energy fall into two main classes depending on the method of its conversion: either heat or electricity. But the energy production form of the solar thermal utilization technology is single and the usual efficiency of photovoltaic technology is lower. Hence, to improve the overall efficiency is one of the issues concerned most in the solar energy utilization.In this paper, a heat pipe-CPV/T(HP-CPV/T) technology is presented which based on the CPV technology. Fresnel lenses are used to be concentration system. High efficiency triple-junction(InGaP/InGaAs/Ge) solar cells are used to generate electricity. What's more, the heat pipe technology is used in the CPV/T system to collect the waste heat to produce hot water and solve the cooling problem of CPV cells. The HP-CPV/T system can produce heat and electrical energy simultaneously with high efficiency. The overall efficiency of solar energy can be also improved. The main contents and results of this study are given as follows:We designed a HP-CPV/T module, built the theoretical model of the HP-CPV/T system and write a Matlab program to solve this theoretical model. The all-day performances of the HP-CPV/T system can be simulated by using the theoretical model and ambient experimental date. The simulation results show that the average electrical efficiency is about 30%, the average thermal efficiency is about 45% and the overall efficiency is about 75%. The theoretical model is also used to analyze the influence of concentration radio and water volume flow rate on the HP-CPV/T module performance. The simulation process has allowed defining the best configuration of the HP-CPV/T module under different parametric conditions. Finally, the cost analysis of the HP-CPV/T system is made. The results show that this technology has many advantages compare with present technologies, such as high electrical efficiency, more closely match the needs of a family, cheaper and smaller. The economy of HP-CPV/T system is sensitive to the concentration ratio and abundant extent of solar resource in different district. The construction cost of a HP-CPV/T system is about 30000~40000 RMB. The payback period is about 5 years in abundant solar resources area of China. In most part of China, the payback period is less than 10 years. The results show that this technology has a good application prospects in abundant solar resources area.