Optical Efficiency Model of Azimuth Tracking Fixed Mirror Solar Concentrator

摘要

The fixed mirror solar concentrator(FMSC)is a collector focusing solar energy through mobile receiver and can be used for supplying industrial process heat.However,this type of collector has a low efficiency and short operating duration in practical applications.In this paper,we propose to install the FMSC on an azimuth tracking device(ATFMSC)and the mirrors are arranged to avoid mutual shading of reflectors for incidence angle of less than 10 degrees to improve its optical performance.Through the integration of the reflected solar radiation distribution function over any reflection point,and then the whole concentrator aperture,we develop the analytical expressions of the system efficiencies to numerically simulate the optical performance of ATFMSC with evaluated tube receiver in different design parameters.It is validated by the previous ray tracing results.The results show that the annual average efficiency of the whole system would be up to 63％with the operating temperature of 400℃ in optimal design.It is better than parabolic trough concentrator and traditional FMSC.The reason is that the longitudinal incidence angle for AZFMSC always remains zero by tracking the sun,which enables the concentrator to operate with high efficiency continually.The results demonstrate its great potential in the field of energy application.