Ray Tracing Study to Determine the Characteristics of the Solar Image in the Receiver for a Scheffler-Type Solar Concentrator Coupled with a Stirling Engine

摘要

This study presents the geometric aspects of the focal image for a Scheffler-type solar concentrator (STSC) using the ray tracing technique to establish parameters that allow the designation of the most suitable geometry for coupling the STSC to a Stirling engine of 3 kWe. The results of the ray tracing software are validated through thermographic images of the STSC solar concentration after modifying the image to establish the geometric areas with the highest temperature. When performing the simulations using the ray tracing software, we found that the most suitable solar image geometry has variations within an elliptical area of 14.25 cm~2 on average with a circular aperture area reflector. While this result is appropriate, the geometry of the receiver would need to be modified to fit a Stirling engine. Finally, when validating the ray tracing results with the image provided by the thermography camera, it was found that the area tends to be elliptical but with an area greater than 36%; this result must be taken into consideration to improve the heat transfer by radiation at the receiver of the STSC.