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In the solar tower thermal power generation system, the precision of the slope angle of the heliostat is the major factor, which influences the efficiency of the system, consequently, this angle should be tested accurately. In this paper, the methods based on laser deflectometry are proposed to measure the shape error of the mirror facet and the connected error of the facets; such apparatus and corresponding software packages are developed. With the help of these two apparatus, the heliostat of 100㎡, consisting of 55 mirror facets of 1.8182㎡ (hexagon), for the 1MWe solar tower power plant in Beijing are measured and connected successfully.

The diffractive optical element (DOE) is always modeled as an ideal pure diffractive element which neglects the refractive dispersion of the element's material. In this paper, a new model of the diffractive optical element is proposed, in which the effect of the refractive dispersion of the DOE's material is considered. The new model is explained and compared with standard diffraction-order expansion with the help of a hybrid system example. The analytical results show that the new model has an important meaning for the exact analysis of the hybrid refractive-diffractive optical system.

A procedure for designing and optimizing heliostat field layout of solar tower thermal power plant is developed. The ray tracing is used for the calculation of the optical efficiency of field. The mathematical theory of the calculation is derived. The parametric search algorithm, which allows variation of the field parameters within a specified range, is used for the optimization of field. The field layout is made automatically according to the no-blocking loss condition and the heliostats are located at the positions where the annual incident cosine value is higher. In this way, the blocking and cosine losses are lowered. Because the optimization of the distance between fore-and-aft two rows of heliostat is avoided, the computer time is reduced effectively. Using this procedure the heliostat field of a 1MWe solar tower power plant was designed. Four modes of layout including North-South cornfield, North-South stagger, Radial cornfield and Radial stagger were experimented and optimized respectively. The comparison of the field efficiency for the four optimized results was made. It is concluded that the North-South cornfield layout is the optimal decision for the 1MWe solar tower power plant.

Computer Generation Image (CGI) system is main part of the flight simulator. Usually, the Image Generation Workstation to be used in CGI system is very expensive. This paper presents a low cost CGI system based on PC and we use it to develop a flight simulator, which has a 3 channels display system with wide field-of-view (horizontal 240°× vertical 60°). First, the paper discusses the architectural principles of CGI system and provides a CGI system based on PC. Second, a type of 3 channels display system is described. The display system is designed in folded flat screen using rear project curtain. Adjacent screen shapes a 100° corner and each channel provides 80°×60° field-of-view. Furthermore, some key technologies, such as image connection, channels synchronization and channels communication, are discussed in detail. At the end of paper, a flight simulator with 3 channels visual scene is described and it is successfully implemented in training pilot. PC-Based CGI system also can be applied to a lot of fields including multimedia commerce, medical media databases visualization, CAD/CAM, scientific computing visualization, and entertainment.