Geometric analysis of three-dimensional effects of parabolic trough collectors

Abstract

An analytical approach, as an extension of one newly developed method – First-principle OPTical Intercept Calculation (FirstOPTIC)–is proposed to evaluate the geometrical impact of three-dimensional (3-D) effects on the optical performance of parabolic trough collectors. The mathematical steps of this analytical approach are presented and implemented numerically as part of the suite of FirstOPTIC code. The new code has been carefully validated against numerical solutions and ray-tracing simulation results. The FirstOPTIC code is then applied to a series of case studies to examine the impact of some important 3-D effects on the intercept factor. A significant result of this work is the correction of the approach generally accepted for the specularity mirror errors for non-zero incidence angles. The new correlation has been validated using the FirstOPTIC approach and ray tracing.