Optical performance and instantaneous efficiency calculation of linear Fresnel solar collectors

Mathioulakis, E.; Papanicolaou, E.; Belessiotis, V.

doi:10.1002/er.3925

Cited by 20 publications

(6 citation statements)

References 24 publications

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“…4 Simultaneously and independently of the world's research in the field of development of PV technology, research on the development of solar concentrators technologies is also carried out. [5][6][7][8][9] The research profile is often directed at obtaining high-temperature heat that can be used in the energy sector. The research on concentrators is propelled by the progressing popularization of ORC technology, Stirling engines, absorption heat pumps, or absorption refrigeration devices.…”

Section: Introductionmentioning

confidence: 99%

A solar simulator numerical modeling for heat absorption phenomenon research in a parabolic trough collector

Bartela

Stanek

Węcel

et al. 2021

Intl J of Energy Research

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Summary The development of renewable solar technologies determines the constant need to improve and increase their energy efficiency. Determination of solar systems performance characteristics must take place under given conditions set by proper standards. Due to unstable weather conditions, including temperature and solar radiation, it is necessary to simulate the laboratory conditions' radiation. For these purposes, so‐called solar radiation simulators are being constructed. This article presents the results of solar simulator modeling for parabolic trough collectors testing. A new approach presented here proposes to use reflectors placed parallel on one plane to simulate both, total radiation and direct radiation used in parabolic concentrator tests. The methodology adopted from the normative approach for evaluating the quality of the simulator is presented. The methodology used for solar radiation simulators was modified to test concentrators in constant, repeatable conditions. The analysis was carried out not only to assess the energy distribution on the plane area but also to assess the energy reaching the tubular absorber external surface. The optical engineering ray tracing software, based on Monte Carlo Method, was used for the analysis. A selection of appropriate light sources, quantity, type, and arrangement of reflectors and their coatings was carried out. Metal‐halides and xenon arc lamps were considered as sources. The distribution of radiation intensity on the analyzed surface was determined for two cases, 22 reflectors and 4 reflectors. The analyzed area was 1 square meter. The evaluation index has been defined to determine the quality of the energy distribution. The influence of the simulator distance on the amount of energy reaching the absorber surface was also analyzed. An estimation of the required financial outlays for analyzed constructions of the simulator was performed. Research has shown that in terms of maintaining the energy field's homogeneity and the price for the entire radiation simulator, it is more reasonable to construct a simulator consisting of 22 reflectors. The construction of such a simulator seems to meet the assumptions required for the correct operation of the radiation simulator. Novelty statement Paper's novelty is the methodology to identify and evaluate solar radiation simulators to simulate heat radiation for parabolic trough collectors. The paper specifies the evaluation index and the way of its interpretation, which determines the radiation distribution on the simulated surface, which is crucial in this issue. In a better and more accurate way, this factor assesses the energy field in terms of quality. Modifying the normative measurement approach of solar radiation on a flat surface, we propose the analysis of concentrated radiation by performing optical analyses using software which are based on the Monte‐Carlo method. The location of light sources on the plane surface is a new approach for PTC testing.

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Section: Introductionmentioning

confidence: 99%

A solar simulator numerical modeling for heat absorption phenomenon research in a parabolic trough collector

Bartela

Stanek

Węcel

et al. 2021

Intl J of Energy Research

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“…Linear Fresnel, shown in Figure , is one type of line‐focus concentrating solar power technology . An array of flat or nearly flat mirrors concentrates sunlight onto a receiver or a receiver assembly . Heat‐transfer fluid (HTF) flows through one or multiple tubes and absorbs concentrated solar energy in the form of thermal power.…”

Section: Introductionmentioning

confidence: 99%

“…1,2 An array of flat or nearly flat mirrors concentrates sunlight onto a receiver or a receiver assembly. [3][4][5][6][7] Heat-transfer fluid (HTF) flows through one or multiple tubes and absorbs concentrated solar energy in the form of thermal power. A secondary reflector may be adopted to enhance optical efficiency and concentration ratio.…”

Section: Introductionmentioning

confidence: 99%

Investigation of temperature distribution on a new linear Fresnel receiver assembly under high solar flux

et al. 2019

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Summary A linear Fresnel collector design with an operation temperature of 300°C or above typically requires a solar flux concentration ratio of at least 20 on the surfaces of the receiver assembly. For the commercial linear Fresnel collector design in this work, the receiver assembly includes a secondary reflector and an evacuated receiver tube. The high‐concentration solar flux may impose additional operating‐temperature requirements on the secondary reflector and receiver tube. Thus, a careful heat‐transfer analysis is necessary to understand the operating temperature of the receiver assembly component surfaces under design and off‐design conditions to guide appropriate material selections. In this work, a numerical heat‐transfer analysis is performed to calculate the temperature distribution of the surfaces of the secondary reflector and receiver glass envelope for a commercial collector design. Operating conditions examined in the heat‐transfer analysis include various wind speeds and solar concentration ratios. The results indicate a surface temperature higher than 100°C on the secondary reflector surface, which suggests that a more advanced secondary reflector material is needed. The established heat‐transfer model can be used for optimization of the other types of linear Fresnel collectors.

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“…They also found that uniform concentrated solar flux incident on the absorber tube could be improved by designing the aim lines and using the mirror with a certain slope error. Mathioulakis [14] investigated the effect of the optical path of the incident beam solar radiation on the performance of a linear Fresnel concentrating solar collector. They formulated model equations for calculating the effects of the reflection angles of the sun rays incident on the mirrors, as well as the incidence angles of the reflected rays on the collector cover, as a function of the sun position and the geometry of the collector.…”

Section: Introductionmentioning

confidence: 99%

Optical Design and Performance Analysis of Linear Focusing Solar Thermal Collectors

Okafor¹

2019

IJSE

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Linear Fresnel solar collector is a focusing concentrator suitable for direct steam generation, industrial process heat, and solar space cooling system and hot water generation for different uses. The optical design and performance simulations, experimental and numerical studies on linear Fresnel solar collector were reviewed. Studies on the optical designs and ray-tracing simulations results indicated non-uniform solar flux distributions on the receiver absorber surface. The optical quality of LFC is low due to its higher incidence angle and the cosine factor. Studies on optimizing the optical errors that affects the optical performance of the LFC are lacking in the literature. Ray tracing results at 0 o incidence angle indicated three different optical losses-geometric configuration, material properties and focus errors losses. Studies on the lateral drift and uncertainty of the direction of the reflected rays, which adversely affect the concentration factor of the LFC are lacking in the literature. The optical performance of a LFC system can be improved through an optimized optical design-mirrors separation, shapes, width and their orientation.

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Optical performance and instantaneous efficiency calculation of linear Fresnel solar collectors

Cited by 20 publications

References 24 publications

A solar simulator numerical modeling for heat absorption phenomenon research in a parabolic trough collector

A solar simulator numerical modeling for heat absorption phenomenon research in a parabolic trough collector

Investigation of temperature distribution on a new linear Fresnel receiver assembly under high solar flux

Optical Design and Performance Analysis of Linear Focusing Solar Thermal Collectors

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