Structural Design And Optimization Of Annular-focus Solar Concentrator

The exploitation of traditional energy such as coal and oil are increasing year by year,but their reserves are limited.To completely get rid of the energy crisis caused by insufficient fossil energy reserves,human beings must develop and utilize new energy sources.As a kind of new energy source,solar energy has many advantages such as huge reserves,clean and efficient,wide distribution,easy conversion,and utilization.Solar photovoltaic conversion can directly convert solar energy into electrical energy with high efficiency,but the cost is relatively high.Solar thermal conversion firstly converts solar energy into heat energy and then convert heat energy into electrical energy.Although the conversion efficiency is lower,the solar panel is not used in the conversion process,and the cost is relatively low.When collecting and utilizing solar energy,the local environment should be considered and these two methods should be properly combined to maximize the benefit between solar power generation efficiency and power generation cost.No matter which form of utilization is used,the core component of the system is the solar concentrator.To improve the efficiency of the solar thermal or photovoltaic systems,the property of the solar concentrator must be improved.In this thesis,two new types of annular-focus solar concentrators are designed and optimized according to the simulation results.Finally,considering the realization of large aperture primary reflector by splicing,a splicing primary reflector annular-focus solar concentrator is designed and its properties are simulated and analyzed.(1)Firstly,the research background and significance are clarified,and the advantages of solar energy utilization are pointed out.The working principle and application scenarios of different types of solar concentrators are analyzed,the advantages and disadvantages of each type are pointed out,and some ideas for the specific design of the annular-focus solar concentrator are provided.(2)Then the theory needed in the design process of the solar concentrator is analyzed.On this basis,two basic indicators for measuring the property of solar concentrator and the actual derivation process are given.At the same time,the specific design methods and simulation methods used in this thesis are provided.(3)Two new types of annular-focus solar concentrators are designed and compared to Cassegrain solar concentrator.The annular-focus solar concentrator with slanting hyperbolic rotating surface secondary reflector and off-axis parabolic rotating surface primary reflector has a high geometric concentrating ratio,and the annular-focus solar concentrator with off-axis parabolic rotating surface primary and secondary reflector has high receiving light spot uniformity.(4)Considering the realization of large aperture primary reflector by splicing,a splicing primary reflector annular-focus solar concentrator with hexagonal sub-reflectors is designed.It is verified that the splicing type annular-focus solar concentrator has better uniformity of receiving light spot and can control the cost while effectively utilizing solar energy.