The Investigation Of Non Tracking Solar Energy Concentrating Technology

At present, the main investigated subject of solar energy concentrating technology is antisolar orientated concentrator. Nontracking concentrator only requires intermittent adjusting its position or unnecessary tracking device evenly, and has many advantages, like low-cost, high-efficiency, easy-operation and maintenance etc. Therefore, it is significant to investigate the concentrating characteristic of nontracking solar concentrators for promoting the development and application of solar concentrating technology.The varying rules of solar irradiation in space and onto the earth surface were investigated in this thesis firstly. The incident solar heat flux density in the six directions of satellite main body was analyzed based on calculating satellite orbit parameter and analyzing its character.The concentrating characteristics were simulated by Monte Carlo Method, and the mathematical model of Monte Carlo Method which describing the beam propagation in interior of the solar concentrating systems. Aitken accelerated iteration method was used to solve the nodes of light and higher-order curved faces, and the initial iterating value was chosen in large scope.Based on the previous investigation, the effects of different parameters to the concentrating ratio of two dimensional trough reflective solar concentrating array were analyzed. By virtue of different concentrating ratio requirements, an intermittent adjusting scheme in which the solar array rolls around the inertial axis of satellite, and the formula calculating the time of adjusting the position was derived.Based on the introduction of the design method of compound parabolic concentrators with plain absorber, an intermittent adjusting scheme of the solar incident elevation angle was presented. The concentrating characteristics of two and three dimensional CPC were analyzed and compared. The loss of light in two dimensional CPC was analyzed and an improved scheme was presented, which has an ideal concentrating performance.From the investigation in this thesis, a comprehensive understanding of the nontracting solar concentrating technology was obtained, and it provides a valuable reference to the design of nontracking solar concentrators.