CIRCE (Convolution of Incident Radiation with Concentrator Errors): A Computer Code for the Analysis of Point-Focus Solar Concentrators

摘要

In this paper a computer simulation code called CIRCE is discussed and examples of its application to several point-focus concentrating collector geometeries are presented. CIRCE, an acronym for Convolution of Incident Radiation with Concentrator Errors, was developed from HELIOS, a large multipurpose cone optics computer code for the analysis of central solar receiver systems. CIRCE was developed with the objective of providing knowledgeable users with an easily used design tool which does not require a large investment of time to obtain results. In CIRCE, the concentrator errors are convolved with the solar intensity profile (sunshape) to produce the flux-density distribution on a specified target plane. CIRCE may be used to analyze reflectors that are spherical, parabolic, or flat in shape and are either continuous surfaces or faceted. The current version of the code is restricted to the analysis of reflector systems which have flat rectangular or circular targets. Presented in this paper are examples of the use of CIRCE for optical performance calculations for both faceted and continuous parabolic dishes. In particular, the sensitivity of the optical efficiency to concentrator errors and to sunshapes (which are a function of the solar intensity level) is investigated for circular targets centered in the concentrator focal plane. Results for a three facet concentrator are also presented and compared with those for an equivalent area continuous parabolic dish to demonstrate the capability of the code and the differences between these concentrators. In this last example, the performance degrading effects of astigmatic focusing are shown for the three facet reflector system. (ERA citation 12:013409)