A model-based approach for optical performance assessment and optimization of a solar dish

Xiao, Gang; Yang, Tianfeng; Ni, Dong; Cen, Kefa; Ni, Mingjiang

doi:10.1016/j.renene.2016.05.076

Cited by 41 publications

(15 citation statements)

References 26 publications

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“…Because the PDC is a typical single point focusing imaging optical device, it usually forms an extremely nonuniform and high‐density solar radiation flux on the absorber surface inside the cavity receiver . This would not only reduce the work efficiency and reliability of the cavity receiver but more seriously will also form a high‐temperature hot spot or a larger temperature gradient on the absorber tube, which will lead to great thermal stress and thermal deformation, thus affecting the safety and service lifetime of the cavity receiver . Therefore, the nonuniform flux distribution will bring more severe challenges to the safe operation of solar dish concentrator/cavity receiver (SDCR) system.…”

Section: Introductionmentioning

confidence: 99%

Mirror rearrangement optimization for uniform flux distribution on the cavity receiver of solar parabolic dish concentrator system

2018

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Summary The nonuniform and high‐gradient solar radiation flux on the absorber surface of solar dish concentrator/cavity receiver (SDCR) system will affect its operational reliability and service lifetime. Therefore, homogenization of the flux distribution is critical and important. In this paper, 2 mirror rearrangement strategies and its optimization method by combining a novel ray tracing method and the genetic algorithm are proposed to optimize the parabolic dish concentrator (PDC) so as to realize the uniform flux distribution on the absorber surface inside the cavity receiver of SDCR system. The mirror rearrangement strategy includes a mirror rotation strategy and mirror translation strategy, which rotate and translate (along the focal axis) each mirror unit of the PDC to achieve multipoint aiming, respectively. Firstly, a correlation model between the focus spot radius and mirror rearrangement parameters is derived as constraint model to optimize the PDC. Secondly, a novel method named motion accumulation ray‐tracing method is proposed to reduce the optical simulation time. The optical model by motion accumulation ray‐tracing method and optimization model of SDCR system are established in detailed, and then, an optimization program by combining a ray‐tracing code and genetic algorithm code in C++ is developed and verified. Finally, 3 typical cavity receivers, namely, cylindrical, conical, and spherical, are taken as examples to fully verify the effectiveness of these proposed methods. The results show that the optimized PDC by mirror rearrangement strategies can not only greatly improve the flux uniformity (ie, reduce the nonuniformity factor) and reduce the peak local concentration ratio of the absorber surface but also obtain excellent optical efficiency and direct useful energy ratio. A better optimization results when the PDC is optimized by mirror rotation strategy at aperture radius of 7.0 m, focal length of 6.00 m, and ring number of 6; the nonuniform factor of the cylindrical, conical, and spherical cavity receivers is greatly reduced from 0.63, 0.67, and 0.45 to 0.18, 0.17, and 0.26, respectively; the peak local concentration ratio is reduced from 1140.00, 1399.00, and 633.30 to 709.10, 794.00, and 505.90, respectively; and the optical efficiency of SDCR system is as high as 92.01%, 92.13%, and 92.71%, respectively. These results also show that the dish concentrator with same focal length can match different cavity receivers by mirror rearrangement and it can obtain excellent flux uniformity.

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Section: Introductionmentioning

confidence: 99%

Mirror rearrangement optimization for uniform flux distribution on the cavity receiver of solar parabolic dish concentrator system

2018

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“…In practice, large dish concentrators are usually assembled with many mirror units forming the parabolic reflecting mirrors and each mirror unit must be accurately fixed in a preset position within the truss structure [6][7][8][9][10]. The fixation or facet adjustment is realized by three support-adjustment structures located on the posterior side of the mirror unit ( Figure 1c).…”

Section: Introductionmentioning

confidence: 99%

A Method for the Installation Measurement and Alignment of a Mirror Unit in the Solar Dish Concentrator

2020

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The mirror unit installation error of the solar parabolic dish concentrator can adversely affect its optical performance causing optical intercept losses and hot spots on the absorber surface, which in turn affect safety. Thus, minimizing mirror installation error is considered very important. In this paper, a new method for the facet installation measurement and facet alignment of the mirror unit in the dish concentrator is presented. Firstly, a “clean” facet installation error measurement method using photogrammetry is presented. The photogrammetry measures the spatial coordinates of three feature points to reverse the mirror facet alignment error parameters. Next, two novel methods, a three-rotation alignment method and two-rotation alignment method for aligning the mirror facet are presented and corresponding mathematical models. The advantage of these alignment methods is that the adjustment value and order for each support bolt can be determined before the mirror facet is aligned, which could provide quantitative adjustment information to operator and avoid repeated adjustments. Finally, validity of the installation measurement and facet alignment method was verified by a numerical simulation and an experiment using a metal facet alignment. The presented methods do not rely on the geometry of the reflector mirror and could therefore have extensive uses in applications such solar tower and trough concentrator.

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“…And public lighting is an important part of current energy consumption. 13 Solar dish systems are applied widely to collect solar radiation for photovoltaic 14,15 and thermal energy employing [16][17][18][19] as a result of their high concentrated radiation intensity 20,21 to make solar energy utilized efficiently. Sunlight optical fiber lighting was proposed in 1980, 8 which has become an important way of implementation.…”

Section: Introductionmentioning

confidence: 99%

“…The system presented in this paper can greatly obtain and concentrate solar radiation by applying a large dish. 13 Solar dish systems are applied widely to collect solar radiation for photovoltaic 14,15 and thermal energy employing [16][17][18][19] as a result of their high concentrated radiation intensity 20,21 to make solar energy utilized efficiently. 14,22 By the surface of dish concentrator coated with beam split thin film 23 and coupled with thin film solar cells, 24 accounting for 38.9% of the total radiant energy of sunlight, the visible (VIS) light (400-760 nm) 25 is split into 2 equal parts by beam split thin film, of which the first 50% VIS light beam is reflected and concentrated onto a secondary reflector and then reflected into fiber-optic bundle (FOB), while the rest 50% VIS light and other spectral radiation (300-400 nm and 760-1800 nm) will be transmitted through the beam split thin film and absorbed and transformed into electricity by thin-film solar cells underneath the beam split thin film.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a large dish-type concentrator solar lighting system for underground car park

Song

Liao

et al. 2018

Int J Energy Res

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Summary To utilize solar energy more efficiently and reduce lighting power consumption in underground public spaces such as car park, a large dish‐type concentrator solar lighting system is put forward along with its evaluation, which is a unique design to apply a laminated layer of beam split thin‐film coating and thin‐film solar cells onto the dish reflector. The collected sunlight is split into 2 parts, one being reflected into a fiber optical bundle and transmitted for daylighting, while the rest being absorbed by solar cells for electricity generation as the other way to replenish daylighting. A set of 4 solar lighting systems using 3.28‐m diameter dish are designed to meet the lighting requirement in a 1771‐m2 underground car park. A mathematical model is adopted to calculate the output power and conversion efficiency of solar cells distributed on the parabolic dish surface. The indoor illuminance distribution is given by lighting simulation. The results indicate that the average daylight illuminance in the car park can vary between 62.7 and 284 lx on February 25, 2016 and between 62.7 and 353 lx on August 17, 2016 for 2 chosen days, respectively. For the presented design, the electricity produced by solar cells is just enough to power light‐emitting diodes for lighting meeting a criterion at night. Considering about 19% conversion efficiency of solar cells and the efficacy of 129.5 lm/W of light‐emitting diodes, the hybrid solar lighting system can have about 40% utilization ratio of solar energy, so it can be concluded that a sufficient lighting provision can be provided by the proposed large dish‐type concentrator solar lighting system for applications in underground car park.

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A model-based approach for optical performance assessment and optimization of a solar dish

Cited by 41 publications

References 26 publications

Mirror rearrangement optimization for uniform flux distribution on the cavity receiver of solar parabolic dish concentrator system

Mirror rearrangement optimization for uniform flux distribution on the cavity receiver of solar parabolic dish concentrator system

A Method for the Installation Measurement and Alignment of a Mirror Unit in the Solar Dish Concentrator

Evaluation of a large dish-type concentrator solar lighting system for underground car park

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