OPTICAL AND THERMAL-ANALYSIS OF A CASSEGRAINIAN SOLAR CONCENTRATOR

For the storage of solar energy in a chemical system, a Cassegrainian type solar collector is investigated. With generalized geometry, a non-skew ray from the edge of the solar disc is followed through the Cassegrainian configuration to the final image to define the image height. Parametric results are presented in a form which can be used to predict performance based on off-axis optics. Equations and graphs allow the incorporation of angular error into the calculations. Slope of 5 for the limiting tangent to the hyperbolic secondary appears near optimum. The focal length of the hyperboloid is not an important factor as long as it is similar to the focal length of the paraboloid. The required diameter for the hyperboloid is typically half the diameter of the paraboloid. A set of design equations is developed, and their use is demonstrated. Design parameters are calculated for chemical reactor loads of 1.0, 0.5, and 0.1 MW. © 1979.