Methodology for an Opto-Geometric Optimization of a Linear Fresnel Reflector for Direct Steam Generation

Abstract

A methodology for an optical optimization of the intercept factor concerning a linear Fresnel reflector is described to increase the amount of solar irradiation that will be delivered in the absorber for Agua Prieta, Sonora; taking the FRESDEMO’s Fresnel field as the reference design. For the performed optimization, the intercept factor is determined as a function of the receiver’s height, establishing a simple criterion for the optimization. The FRESDEMO’s field description is determined and briefly discussed, next compared with the proposed optimization. The compound parabolic concentrator (CPC) Winston function for a circular absorber is modified to relocate the cusp of the reflector and the absorber. This modified CPC will redirect all the reflected rays that do not hit directly the absorber, as in the FRESDEMO field, so all of them are captured by the absorber. Through ray-tracing, the graphic flux distribution in the receiver aperture is conceived. This flux distribution is compared with the FRESDEMO field and with a PTC with a flat absorber, ensuring an adequate optimization regarding the intercept factor. The result of the opto-geometric optimization is compared between the FRESDEMO and the optimized field for a specified thermal process, addressing a considerable reduction in the length of the loops.

Alternative Methodology for Modeling Direct Steam Generation in Parabolic Collectors: A Study Case in Northeast Mexico

“…where each C i is a functional parameter of the temperature, obviously positive (C i > 0), which can be obtained from any database of thermodynamic properties. This equation can be used with confidence, as validated in [27] with data recovered from the DISS loop [10,16].…”

“…For the five equations of 1, the radiation absorption phenomena in the absorber tube and the transparent cover are treated as surface heat fluxes. In addition, the temperatures, heat fluxes and all thermodynamic properties are uniform around the cross-sectional area (1D model) [27]. These simplifications lead to theoretical values larger than the real ones, but with adequate results [21].…”

“…For the convection between the absorber tube and the heat transfer fluid, there are two cases: the Pethukhov or Gnielisnki equation [28] for the single phase fluid and the Gungor and Winterton correlation for the two-phase flow [29]. The transformation of the two-phase flow equation is described in [27], resulting in the following:…”

Review of Concentrated Solar Power Technology Applications in Photocatalytic Water Purification and Energy Conversion: Overview, Challenges and Future Directions

“…In the past few decades, LFRs have also been studied and developed, and they have been widely used in photo-thermal power generation projects [70,71]. As shown in Figure 3d, the main structure of an LFR includes segmented flat mirrors which are mounted in parallel (as a primary mirror) and a secondary mirror located above the primary mirror array.…”

“…First, solar-concentrated photoreactors may provide excessively high light irradiance and reaction temperatures for photocatalytic reactions [17,102]. Figure 7a shows the ability of some typical PTRs [45,62,[103][104][105], PDRs [49,[106][107][108], SPTs [69] and LFRs [70,72,109] to concentrate solar energy. Usually, these solar concentrators are used to concentrate solar energy efficiently to produce high temperatures which can be employed in thermal engineering processes such as in photo-thermal power plants.…”