Optical study of solar tower power plants

Eddhibi, Fathia; Amara, Mahmoud Ben; Balghouthi, Moncef; Guizani, Amenallah

doi:10.1088/1742-6596/596/1/012018

Cited by 23 publications

(14 citation statements)

References 7 publications

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“…where SM is the solar multiple, Ae is the total area of the heliostats, η [32] is the optical efficiency of the heliostats field, taking into account the reflection coefficient of the mirrors, the transmissivity of the atmosphere, the cosine, shadowing, blocking, and spillage effects of the individual heliostats and the absorption coefficient of the receiver, Ploss is the sum of the radiative and the convection losses of the receiver, m is the fluid flow rate, H(TOR) is the enthalpy of the fluid at the outlet of the receiver and H(Tor) is the enthalpy of the fluid at the outlet of the regenerator. The radiative loss Ploss was evaluated by the equation:…”

Section: Calculation Model Of the Brayton Cyclementioning

confidence: 99%

A Calculation Method to Estimate the Thermodynamic Performance of Solar Tower Power Plants with an Open Air Brayton Cycle and a Combined Cycle

Ferraro¹,

Marinelli²,

Settino³

et al. 2020

TI-IJES

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In this study, a method will be described to evaluate the performance of two thermodynamic solar tower power plants of 50 MW. The first is an open air Brayton cycle, equipped with an inter-cooled compressor and a regenerator while the second consists in a Brayton-Rankine combined cycle. The annual performances of the two systems have been estimated, in terms of electricity, average annual efficiency of the heliostats field-receiver system, efficiency of the thermodynamic cycle and of the entire plant. The performances of the two plants have been compared to conventional plants using molten salts. The analysis carried out in this study shows that the technical performance of the combined cycle is superior to the Brayton cycle, and both systems have better performances than conventional solar tower systems using molten salts. The specific energy of the Brayton plant is 11.5% greater than that obtained for the plant using molten salts, while for the combined cycle there is an increase of 38.7% with respect to the system using molten salts.

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Section: Calculation Model Of the Brayton Cyclementioning

confidence: 99%

A Calculation Method to Estimate the Thermodynamic Performance of Solar Tower Power Plants with an Open Air Brayton Cycle and a Combined Cycle

Ferraro¹,

Marinelli²,

Settino³

et al. 2020

TI-IJES

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“…The heliostat was affected by the fenestration geometrical factors like external solar shading, despite its flexible weight, height, or shape (spherical/circular). The freer the heliostat geometry, the more the decrease in the radiation reflecting on the receiver surface, associated with the sunlight fallen on the heliostat surface, because of optical losses [12] [42].…”

Section: Heliostat Fieldmentioning

confidence: 99%

“…On the other hand, the effective reflected area was seen to be accountable to a majority of the heliostat field losses, which consisted of the partition between the heliostat and perpendicular areas to the transmission of the reflected radiation [42]. This effect was based on the sun position and placement of every heliostat mirror compared to the receiver [21].…”

Section: Losses From the Heliostat Fieldmentioning

confidence: 99%

“…This effect was based on the sun position and placement of every heliostat mirror compared to the receiver [21]. This heliostat position could be determined using a tracking process such that the mirror surface intersected the angle between the sunlight and line of the heliostat and external receiver [42]. This process is described in Figure 4 (I), wherein the reflected area of the heliostat B was lesser than that reflected by the Heliostat A, which indicated that as the angle between the regular surface and radiation incidence (a -incidence angle) increased, the reflected area also decreased.…”

Section: Losses From the Heliostat Fieldmentioning

confidence: 99%

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Solar Tower Power: The Impact of External Receiver on Optimal Performance and Energy Storage

Shatnawi,

Lim,

Ismail

2019

IJEAT

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An external receiver was seen as a major component of the Solar Tower Power (STP) plant. This generated stable power from concentrated sunlight. However, the flux distribution on its surface was an issue related to the external receiver that could affect the performance and energy storage in STP. The heat flux increased during long-term use, failure reduction, receiver efficiency and performance. The main advantage of the STP structure was its substantial heat storage capacity which allowed the system to generate stable and continuous electric power. In this study, the researchers reviewed existing literature to investigate the effect of the STP external receiver on the optimum energy storage and performance of the STP; especially regarding the solar flux distribution and efficiency. The researchers aim to improve the external receiver’s optimal performance without affecting the incident heat fluxes. The literature review indicates that ideal receiver conditions lead to solar energy flux distribution optimal performance. Therefore, system optimisation was necessary to satisfy all limitations; like loss occurring due to heliostat field, solar flux flow patterns, external tubular receiver designs, and Heat Transfer Fluid (HTF) selection. These limitations, along with factors affecting these limitations, are reviewed in this study.

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“…heliostat reflectivity, and shading/blocking are assumed to be constant with values of 0.91 and 0.95 respectively. This is reasonable based on the approaches taken by other authors (Bellos and Tzivanidis, 2018, Kistler, 1986, Eddhibi et al, 2015. Losses associated with TES are assumed to be negligible (Zhang et al, 2013).…”

Section: Other Sources Of Lossesmentioning

confidence: 93%

UQ eSpace

Balaji¹

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The electrification of remote locations that lack grid-connectivity is a global challenge. In Australia, off-grid electricity accounts for 6% of total generation. At present these needs are met through the use of fossil fuels, resulting in a high electricity cost, and environmental consequences. With the present drive towards reducing greenhouse gas emissions and increasing the use of renewable energies, there is an opportunity to transition from the use of fossil fuels in remote locations to the use of renewables. In this regard, the hybridisation of renewable technologies with diesel generators has been shown to improve reliability and increase penetration. This project aims to explore the use of a hybrid renewable energy system consisting of solar photovoltaic (PV) with battery storage, concentrating solar thermal (CST) with thermal storage and diesel generators for off-grid power generation. The analysis considers two major consumer groups, viz. mining sites and communities, at three locations-Newman, Port Augusta and Halls Creek. In particular, the solar thermal system explored utilises a supercritical carbon dioxide power cycle, due to the suitability of this technology at scales appropriate for off-grid use. This is necessitated due to the fact that existing CST plants typically utilise a steam Rankine cycle, which suffers reduced efficiencies at small scales. Based on the existing literature, the proposed technologies have been found to present excellent suitability to this application. A key area of interest with regards to the CST plant is the turbine inlet temperature, due to higher temperatures presenting a higher power cycle efficiency, which offers a route to reduce energy costs. However, these higher temperatures increase the power cycle and receiver costs, due to the requirement of higher performance materials. Increases in receiver losses are also seen at higher temperatures. Similarly, the CST plant also presents increasing field losses with increasing size. In this analysis, three turbine inlet temperatures (namely 650°C, 800°C and 1000°C) are explored. A Python program was developed, encapsulating the thermodynamics and operating characteristics of each technology, to simulate the performance of the hybrid system over the course of one year, based on weather data and a synthetic load profile. This simulation was then used along with an optimisation function to identify the optimal mix of technologies in the hybrid system based on the minimum levelised cost of energy (LCOE). Using this program, results were generated for community and mining consumer groups at the three locations, and it was found that in both cases the optimal mix consists of CST as the primary source of baseload power, with 12-15 hours of thermal storage. While PV and diesel generators were both shown to be necessary, they represent a smaller fraction of the total energy production and serve as supplementary sources of power. Notably, none of the optima included battery storage, highlighting the high costs of this technology ...

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Optical study of solar tower power plants

Cited by 23 publications

References 7 publications

A Calculation Method to Estimate the Thermodynamic Performance of Solar Tower Power Plants with an Open Air Brayton Cycle and a Combined Cycle

A Calculation Method to Estimate the Thermodynamic Performance of Solar Tower Power Plants with an Open Air Brayton Cycle and a Combined Cycle

Solar Tower Power: The Impact of External Receiver on Optimal Performance and Energy Storage

UQ eSpace

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