Prediction of focal image for solar parabolic dish concentrator with square facets-an analytical model.

Abstract

Solar parabolic dish concentrator is one of the high-temperature applications of more than 400°C for thermal and electrical power generation. In the solar parabolic dish concentrator, the arrangement of reflectors over the surface area is the significant factor for effective concentration of solar radiation. Also, focal image is one of the most influencing parameters in the design of receiver. Among the various reflectors, the square-shaped reflectors (facets) are comparatively effective in converging the incoming radiations to attain better focal image. In this regard, an attempt has been made to predict the focal image diameter of a solar parabolic dish concentrator with a square facet of different influencing parameters using a novel mathematical model. The influencing parameters considered for the study are aperture diameter, rim angle, and facet length of the dish concentrator. Using the model, the focal image dimension and aperture area of a solar parabolic dish concentrator with square facets can be predicted accurately for efficient design of a solar parabolic dish collector system. Finally, the model is validated with the experimentally obtained focal image diameter. The current model is in good agreement with the experimental value, with a deviation of 8.84%. Hence, the proposed model can be used for the design of parabolic dish systems.