Solar Dish Collector Research Papers (original) (raw)

2025, Renewable and Sustainable Energy Reviews

The Stirling chiller has multiple brilliant applications, especially with its low power consumption, rapid cooling, high reliability, light weight, high efficiency and is capability of running on solar energy. In this work, studies are carried out on the generation of cold by a Dish-Stirling/Stirling refrigerator system. is studied to obtain generate cold. The proposed system is found to be more efficient than existing solar refrigeration systems and it is also environmentally friendly due to its non-toxic working fluid. Moreover, its Dish-Stirling solar collector is capable of operating in warmer regions compared to other solar collectors. The system consists of a solar collector to transform solar energy into heat, a Stirling engine to convert mechanical thermal energy into what?, a gear system to couple the refrigerator and Stirling engine and a refrigerator Stirling for cold production. The system is modelled on the basis of finite-time thermodynamics. Then the equations are solved analytically. The simulations are performed with MATLAB software. In addition the thermal losses of the solar collector of the Stirling engine and the refrigerator are taken into account in this model. The equality of cycle time and power were considered as constraints of the system. The effects of operational and design parameters on system performance are studied. The results show that the Dish-Stirling/Stirling refrigerator has a low COP and a high cooling capacity unlike the photovoltaic/Stirling refrigerator. In addition, the optimal solar thermal COP is 33.3% when the optimum absorber temperature is 800 K. The maximum cooling rate is 1720 W at The optimum engine power is 4061.9 W at the ecological coefficient of performance is 47,3 at the optimal thermo-economic function is 0.157 at The COP0 of the Stirling refrigerator is 50.005 % (50,0 %) at This system can be used for preserving medicines in pharmacies.

2025

This paper presents optical simulations of 10 kW el Eurodish Dish/Stirling unit erected at the CNRS-PROMES laboratory in Odeillo in FRANCE. The global thermal model of the energy conversion, SIM_ED_PROMES, developed by PROMES laboratory has shown that the main heat losses are situated in the optical system package (parabolic concentrator, solar receiver). To increase the net solar-to-electrical efficiency, it is essential to know the optical performances of the subsystem formed by the solar receiver and the parabolic concentrator. In 2005, the "color-coded targets" method developed by the DLR was used to measure slope errors of the parabolic concentrator. The high spatial resolution of this method is used to simulate the concentrator behaviour using the ray-tracing code SOLTRACE developed by the NREL laboratory. In order to verify the concentrator model, the solar flux distributions calculated by SOLTRACE are compared to flux measurements close to the focal plane. The comparison shows a good agreement especially in the shape of the flux map in the absorber plane. Currently, the laboratory uses SOLTRACE to estimate flux distributions for different receivers. Flux maps are introduced in the thermal model SIM_ED_PROMES to calculate the absorber temperature levels, the heat losses, the receiver efficiency and the Stirling engine efficiency.

2025

• Evaluating the flow rate influence on the spiral collector. • Comparing the thermal efficiency of a spiral collector with a changing flow rate. • Highlighting the influence of some factors on the spiral collector's performance, such as... more

2025, International Journal of Thermophysics

The aim of the present study was to investigate heat transfer characteristics of turbine oil-based nanofluids inside a circular tube in laminar flow under a constant heat flux boundary condition. Oil-based nanofluids were prepared dispersing less than 1 % volume concentrations of CuO, TiO 2 , and Al 2 O 3 nanoparticles in turbine oil using a two-step method. The primary objective was to evaluate and compare the effect of different volume concentrations and nanoparticle types on convective heat transfer. An experimental apparatus was designed and constructed to measure the heat transfer coefficient and the Nusselt number of the samples. Due to the high Prandtl number of the nanofluids (about 350), it was concluded that the nanofluids were in the developing region. Experimental results clearly indicated that all of the added nanoparticles improved both the heat transfer coefficient and the Nusselt number of the turbine oil. A nanofluid is more capable than a single-phase fluid insofar as removing heat from high heat flux surfaces. The highest values of the Nusselt number and the Nusselt number ratio (the ratio of the nanofluid Nusselt number to that of the pure turbine oil) belonged to the CuO/turbine oil nanofluid. Among the sample nanofluids, the highest Nusselt number ratios belonged to CuO/turbine oil (0.50 %), TiO 2 /turbine oil (0.50 %), Al 2 O 3 /turbine oil (0.50 %), and a Reynolds number of about 800 which were 1.38, 1.31, and 1.15, respectively. Moreover, so as to determine the efficiency of a nanofluid, the ratio of the pressure drop and Nusselt number of three nanofluid samples were compared with that of the base fluid. A third parameter (performance index) was evaluated to determine the possibility of practically using such for rating nanofluids. All the obtained performance indexes for CuO/turbine oil and TiO 2 /turbine oil were

2025

NEOM is a proposed $500 billion smart city project planned to be built in Saudi Arabia. It aims to be a hub for innovation, sustainability, and quality of life, and will incorporate cutting-edge technology and renewable energy solutions. NEOM aims to transform the region into a hub for the future, attracting businesses and individuals from all over the world.. This article explores the potential application of solar still desalination in the NEOM region. Solar stills are a cost-effective and environmentally friendly solution for producing fresh water from saltwater sources. In the NEOM region, where access to fresh water is a major challenge, solar still desalination can play a significant role in meeting the growing demand for potable water. This research discusses the principles and components of solar stills, and the various types of solar stills that are currently available. This work also evaluates the performance and efficiency of solar stills, and their potential to provide large-scale water production in the NEOM region. Finally, the article highlights the potential benefits and challenges associated with implementing solar still desalination in the NEOM region, and provides recommendations for future research and development. This research contributes to the growing body of literature on sustainable water management, and has important implications for policymakers and water resource managers in the NEOM region and beyond. Keywords Sustainable desalination • Sustainable water resources • Solar still • Modeling • NEOM List of symbols Absorptivity s Surface albedo Tilt angle, thermal expansion coefficient (deg) Thickness, depth, Declination (m) Emissivity coefficient (W/m 2 K 4 ) Surface azimuth angle Incidence angle (deg) Reflectivity, density (Kg/m 3 ) Stefan-Boltzmann constant Transmissivity Latitude Hour angle Incidence angle (deg)

2024

This paper proposes a new type of solar trough collector with a spliced cylindrical mirror and develops a new ray-tracing method to predict and optimize its performance. The mirrors of this system are composed of multiple cylindrical mirrors whose centers are on a parabola, and the normal vector of the centers of each cylindrical mirror is consistent with the normal vector of the parabola point where it is located. The new ray-tracing method is based on the transverse distribution of solar radiation, and it has been validated with Soltrace, with the maximum intercept factor error in the calculations being less than 0.31%. This paper compares the spliced cylindrical mirror trough solar system with the conventional parabolic trough system and finds that the influence of cylindrical, spherical, and coma aberration can be reduced to negligible levels by adjusting the system design. At the same time, the slope error and cost of the cylindrical mirror are much less than the parabolic mirror so it has better performance from numerical simulation. The spliced cylindrical mirror system can be further optimized to achieve an annual net efficiency of 65.52% in the north-south horizontal axis tracking mode.

2024, Applied Sciences

2024

In this study, thermal performance of a proposed point-focus solar collector for low power applications was estimated under different operating variables. For this purpose, theoretical analysis was employed with varying relevant parameters, using a set of thermodynamics and energy equations, i.e., ambient temperature, beam solar insolation, wind speed, wind incidence angle and wall temperature of the absorber. The results show decreasing trend of the wind incidence angle along with increasing the convective heat loss coefficient as the highest related values obtained under head-on wind flow, but the wall temperature of the absorber exerts negligible influence. The maximum thermal efficiency of 79.68% was obtained in August with the side-on wind flow of 4.9 ݏ ⁄ and an ambient temperature of 29.2Ԩ when the absorber wall temperature has a minimum value of 150Ԩ.

2024, Revue des énergies renouvelables

-La comparaison de deux géométries du réseau du caloporteur d'un capteur plan classique, nous oblige à mettre en évidence l'influence des pertes par convection sur le bilan optothermique de ce capteur. Partant des caractéristiques optiques et géométriques du capteur, des caractéristiques hydrauliques du fluide caloporteur, nous évaluons avec le maximum de précision les différentes composantes du bilan thermique en tenant compte notamment des gradients de température dans l'absorbeur. Ce travail a été mené avec de l'eau pressurisée comme fluide caloporteur. Notre étude théorique a été menée en utilisant un programme de calcul développé au laboratoire se basant sur la méthode des différences finies. Ce programme a été validé par les résultats expérimentaux dans les mêmes conditions météorologiques. Le convertisseur type serpentin a été choisi.

2024

1 Research student Department of Mechanical Engineering, P.V.P.I.T, Budhgaon, Sangli, Maharashtra, India 2 Associate Professor, Department of Mechanical Engineering, P.V.P.I.T, Budhgaon, Sangli, Maharashtra, India ---------------------------------------------------------------------***---------------------------------------------------------------Abstract—The Parabolic Dish Solar Collector technology is very useful as it is used for approximately all solar energy applications such as steam and power generation, water heating, air heating etc. In this paper work the performance analysis of parabolic solar dish collector is done with the use of different reflecting materials. In this work a Parabolic Dish Solar Collector system is fabricated for hot water production. Water is used as a working fluid and is recirculates from the storage tank to the absorber tank with the help of a pump. The main aim in the work is to increase the temperature of water in the storage tank to a maximum va...

2024

Against a backdrop of our world‟s changing climate solar thermal power generation shows great potential to move global energy production away from fossil fuels to non-polluting sources. A parameter study was conducted based on the previous analysis to improve specific aspects of the initial design using a value of benefit analysis to evaluate the different design. This project focused on the design, analysis and verification of a high temperature solar receiver. Computational Fluid Dynamic (CFD) analysis of Radiation model is carried out with new geometry design of receiver. Discrete Transfer Radiation Model (DTRM) model is used for numerical simulation.

2024

The present project was conducted so as to improve the performance of a solar still, the improvement of performance is of importance as these still are used to obtain clean drinking water from salt water and they are mostly designed to be used for domestic purpose in coastal regions were water used is salt water, areas such as bagamoyo, dar es salaam.
To achieve this objective of improving the performance the area that was looked upon was on the factors that affects the solar still which were determined to be ambient condition, design condition, and operating conditions.
The project involved doing a small modification on the solar still by changing the collecting pipes, other operating conditions were also determined like the angle of inclination of the glass, the water depth and lastly PCM was integrated. Different experiment was conducted as according to the methodology and results were obtained after analysis there was greater improvement in water obtained a day especially the evening hours due to PCM. The water collected ranges from 290ml which is 2.4L/m2-day up to 350 which is 2.8L/m2-day.

2024, HAL (Le Centre pour la Communication Scientifique Directe)

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2024, L'impiego di motori a ciclo Stirling nella trazione

Appunti di storia automobilistica.

2024, International Journal Of Engineering Research And Development

International Journal Of Engineering Research And Development, 20(7): 495-507. (www.ijerd.com). Open Access (see journal's link).

2024, International Journal of Heat and Technology

This study investigates the novel design of a hybrid solar distillation system. The system includes a parabolic trough collector (PTC), cascade solar still and a single slope single basin solar still as the recycling unit. Thermodynamic parameters of saline water were considered in our energy balance calculations, which improved the accuracy of our results. The experiments were conducted in Tabriz, Iran, during September. Using these three stages, the production rate achieved about 6 kg/m 2 .day in cascade solar still, 4 kg/m 2 .day for the single basin solar still and 450g solid salt. Usually, cascade solar stills have better performance in comparison to other solar stills. To prevent salt deposition among the stairs of cascade solar still, the water should flow through the stairs causing the brine to leave. Recycling brine could remove one of the biggest environmental disadvantages of cascade solar stills. PTC can generate more efficiently than evacuated tubes and flat-plate solar collectors. The total efficiency of the hybrid solar distillation reached 41%. The novel hybrid solar distillation system improved the efficiency of the distillation system and removed brine of cascade solar still.

2024, Journal of Physics: Conference Series

Natural Vacuum Solar Desalination technology was designed and built for one of solutions for water scarcity issues right now. An evaporator as the main part of this system should be analyzed to achieve a good result (fresh water productivity). The evaporator is used as an evaporation chamber to evaporate seawater which will be condensed to water storage. The commercial code CFD ANSYS Fluent 16.1 has been used to simulated and analyzed of heat and mass transfer inside the evaporator. There is no laminar model was used in this work with the temperature of heating coil was 70℃ and the operation pressure was under atmospherical pressure. In this work, the results of simulation and experimental will be compared to be a validation. The highest temperature 72℃ was in heating coil and the lowest temperature 38℃ was in a body of evaporator based on the simulation result. The temperature of heating coil was increasing during evaporation processes. From these comparisons, shows there's a little discrepancy with a magnitude of error between 0,02% to 33%. It also shows the method has been used is right for analyzed and simulated about evaporation-condensation processes.

2024, Universal Journal of Mechanical Engineering

This research work is concerned with comparative experimental analyses performed on parabolic solar collector. It presents the experimental analyses on parabolic solar collector at various operating conditions. For this experimental work, parabolic solar collector was fabricated. Various comparisons have been done between mirror concentrator and aluminium sheet concentrator. Experimental readings have been taken at 12:30 PM and at 01:30 PM and then performance of the solar collector has been found. For performance analyses, different pipe materials have been selected like copper pipe, aluminium pipe, brass pipe and mild steel pipe as receiver pipes. And different fluids have been selected for analyses like water and antifreeze ethylene glycol (coolant) as working fluids. Flowing fluids outlet temperatures, heat transfer rates and instantaneous efficiencies have been found at various operating conditions and then best operating condition for solar collector has been identified. This experimental research work can be concluded as up to 92% instantaneous efficiency and 12.2ºC temperature difference between inlet-outlet temperatures are achieved with aluminium sheet collector but 1208.99 W heat transfer rate is found through mirror collector with copper pipe and coolant. After all experiments, calculations and graphs have been plotted, concluded that overall performance of fabricated solar collector with the aluminum sheet collector, copper pipe and coolant is the best.

2024, Journal of Thermal Analysis and Calorimetry

This research article presents an experimental performance comparison of three cases, viz (1) conventional solar still, (2) single slope solar still incorporated with parabolic trough collector, and (3) single slope solar still incorporated with parabolic trough collector and packed layer of glass balls in the basin. The resulting heat due to incident solar energy on the parabolic trough collector is transferred by means of a finned piped (steel) loop heat exchanger that is immersed in the still basin. Experimentations were carried out during the winter with saline water depth 50 mm in the still basin. The packed layer of glass balls acts as a thermal storage medium to improve the heat transfer. The analysis shows that the case (3) has the highest freshwater productivity followed by the case (2) and (1), respectively. The percentage increase in the yield of solar still is 152 for case (3) and 130 for case (2) when compared to conventional solar still. Similarly, the highest solar still efficiency is reported for case (3) which is equal to 14.96% followed by the case (2) with 13.96% and the least is for case (1) with 13.5%. An economic analysis is also carried out for all the above-mentioned cases to show the feasibility of the integration of parabolic trough collectors with a packed layer of glass balls in the still basin. Both the efficiency improvement and the economic viability show that the proposed modifications are highly promising for the water-scarce regions.

2024, Energy Procedia

This study presents the geometric aspects of the focal image for a Scheffler-type solar concentrator (STSC) using the ray tracing technique to establish parameters that allow the designation of the most suitable geometry for coupling the STSC to a Stirling engine of 3 kWe. The results of the ray tracing software are validated through thermographic images of the STSC solar concentration after modifying the image to establish the geometric areas with the highest temperature. When performing the simulations using the ray tracing software, we found that the most suitable solar image geometry has variations within an elliptical area of 14.25 cm 2 on average with a circular aperture area reflector. While this result is appropriate, the geometry of the receiver would need to be modified to fit a Stirling engine. Finally, when validating the ray tracing results with the image provided by the thermography camera, it was found that the area tends to be elliptical but with an area greater than 36%; this result must be taken into consideration to improve the heat transfer by radiation at the receiver of the STSC.

2024, Applied Energy

h i g h l i g h t s Receiver and absorber design methodology based in a solar image in the focal surface. Stirling absorber dimensions based in a solar image in the focal surface of a STSC. Comparative study of a solar image in the focal surface from different optical model. A Monte-Carlo ray-tracing method was used to set STSC cavity receiver aperture.

2024, HAL (Le Centre pour la Communication Scientifique Directe)

2024

L'entrée d'une technologie de pompage solaire thermodynamique basse température des années 1970 au sein des collections du Musée des arts et métiers à Paris a été l'occasion d'une nouvelle lecture technopolitique des énergies renouvelables. Ce projet muséal, s'adressant aussi bien à la recherche qu'au grand public, permet donc de réfléchir à ce que l'on peut dénommer-en emprunt à l'anthropologie des sciences anglo-saxonne-une « énergopolitique ». Le propos restitue la généalogie sociale et intellectuelle du projet, puis évoque les obstaclesépistémologiques, pratiques, muséographiques-auxquels il a dû s'affronter. Il se conclut sur la manière dont ce parcours est significatif de la difficile mise en débat de l'histoire des technologies liées aux énergies renouvelables, et particulièrement ici de l'énergie solaire.

2024, International journal of ambient energy

In this review, desalinated water quality analysis in various solar stills are examined. Many authors have performed experiments in solar stills along with the testing of physical and chemical water quality examinations for feed water and desalinated water. This was performed on different types of feed water, namely, ocean water, bore well water, water from lakes, tap water and synthetic water from the laboratory are investigated. This research is important to understand solar still performance for a variety of different water types. Based on the investigation, the pH and TDS value (before & after treatment) of the synthetic water, brackish water, ground water, lake water and sea water are improved and is compliant with WHO-2017 and BIS-2010 water quality standards. Water quality results of dissolved macro minerals (before & after treatment) in the water are reviewed and useful conclusions are drawn.

2024, Journal of Advanced Research in Fluid Mechanics and Thermal Sciences

Several types of flat plate solar collectors have been designed and developed with various technical parameters involved in the design. The inappropriate flat plate solar collector parameter design and material chosen will affect its performance. Investigation on the effect of flat plate absorber collector material, glass thickness, air gap distance, thermal cell absorber thickness, and flat plate absorber base collector thickness on the performance of solar thermal collectors was conducted in this work. The experiment was performed using the solar simulator with solar radiation of 450 and 750 W/m2. The flat plate absorber collector materials used in this experiment were stainless steel 304 and aluminum. The glass thickness used in this experiment was 2.0, 3.0, 4.0, 5.0, and 10.0 mm. The air gap between the flat plate absorber and glass used in this experiment was 0, 5.0, 10.0, 20.0, and 30.0 mm. The stainless steel thermal cell absorber thickness applied in this experiment was 0.5,...

2024

Les lentilles à échelons de Fresnel par Vincent Guigueno, historien, enseignant-chercheur à l'Ecole des Ponts Avec le Rapport contenant l'exposition du système adopté par la Commission des Phares, pour éclairer les côtes de France, publié en 1825 par Augustin Fresnel et l'hydrographe Paul-Edouard de Rossel, le Mémoire sur un nouveau système d'éclairage des phares 1 est le texte fondateur pour comprendre l'histoire de la signalisation maritime. Après avoir rappelé le contexte dans lequel Fresnel rédige ce mémoire, nous décortiquerons le processus d'innovation dont la fameuse lentille n'est qu'un élément. LES PHARES EN FRANCE AU DEBUT DU XIX E SIECLE Au moment de la publication du Mémoire, une vingtaine de phares illuminent les côtes de France, dont la prestigieuse tour de Cordouan 2. Autour de 1820, des projets sont lancés par les ingénieurs des Ponts à l'embouchure de la Loire (le Four du Croisic) et au large de Marseille (Le Pl anier). Le di recteu r général des Ponts et chaussées et des Mines, Louis Becquey (1760-1849), que Fresnel remercie à la fin de son mémoire, réactive en 1819 la Commission des Phares, créée sous l'Empire (avril 1811). La Commission, composée de savants, de marins et d'ingénieurs, avait pour tâche d'examiner un projet d'éclairage par des feux bleus et rouges proposé sous l'Empire par un officier de Marine. Plus généralement, elle devait réfléchir à un « système » pour l'ensemble des côtes de France. Le contexte de guerre avait considérablement limité ses travaux. Ceux-ci reprennent en 1818, quand François Arago (1786-1853), enseignant à l'École polytechnique, membre de l'Académie des Sciences et du Bureau des Longitudes, est nommé à la Commission. Il appelle auprès de lui un jeune ingénieur des Ponts et Chaussées, Augustin Fresnel (1788-1827), qui rectifie les routes d'Ille et Vilaine et tente, sans succès, de rejoindre la capitale.

2024, BibNum

Les lentilles à échelons de Fresnel par Vincent Guigueno, historien, enseignant-chercheur à l'Ecole des Ponts Avec le Rapport contenant l'exposition du système adopté par la Commission des Phares, pour éclairer les côtes de France, publié en 1825 par Augustin Fresnel et l'hydrographe Paul-Edouard de Rossel, le Mémoire sur un nouveau système d'éclairage des phares 1 est le texte fondateur pour comprendre l'histoire de la signalisation maritime. Après avoir rappelé le contexte dans lequel Fresnel rédige ce mémoire, nous décortiquerons le processus d'innovation dont la fameuse lentille n'est qu'un élément. LES PHARES EN FRANCE AU DEBUT DU XIX E SIECLE Au moment de la publication du Mémoire, une vingtaine de phares illuminent les côtes de France, dont la prestigieuse tour de Cordouan 2. Autour de 1820, des projets sont lancés par les ingénieurs des Ponts à l'embouchure de la Loire (le Four du Croisic) et au large de Marseille (Le Planier). Le directeur général des Ponts et chaussées et des Mines, Louis Becquey (1760-1849), que Fresnel remercie à la fin de son mémoire, réactive en 1819 la Commission des Phares, créée sous l'Empire (avril 1811). La Commission, composée de savants, de marins et d'ingénieurs, avait pour tâche d'examiner un projet d'éclairage par des feux bleus et rouges proposé sous l'Empire par un officier de Marine. Plus généralement, elle devait réfléchir à un « système » pour l'ensemble des côtes de France. Le contexte de guerre avait considérablement limité ses travaux. Ceux-ci reprennent en 1818, quand François Arago (1786-1853), enseignant à l'École polytechnique, membre de l'Académie des Sciences et du Bureau des Longitudes, est nommé à la Commission. Il appelle auprès de lui un jeune ingénieur des Ponts et Chaussées, Augustin Fresnel (1788-1827), qui rectifie les routes d'Ille et Vilaine et tente, sans succès, de rejoindre la capitale.

2024, MATEC Web of Conferences

For the flow through type selected geometry of the designed evacuated tube collector ETC, a three dimensional simulation and analysis of the thermal performance was done, using the ray-tracing solar load model provided by the ANSYS-FLUENT software. In this model the solar radiation heat flux is solved using fair weather condition radiation equations, and then solar radiation load is considered as a heat source term in the energy equation. The thermal effects of the fluid flow and heat transfer in the collector, temperature fields as well as the solar radiation distribution, and other related factors under the different conditions have been discussed and analyzed.

2024, Solar Energy

Efficiency of concentrating solar power system (CSP) can be significantly reduced by heat losses from the receiver. So, the assessment of heat losses is the key to improve its thermal performance. This paper attempts to present a numerical simulation to assess the heat losses from a cavity receiver by using Lattice Boltzmann Method (LBM) coupled with net radiation method. Combined natural convection and surface radiation heat losses in open rectangular solar cavity receiver is presented. The wall facing the opening is subjected to parabolic temperature profile. The other walls are insulated. Cavity walls are assumed to be diffuse, gray and opaque while the open boundary is assumed to be a fictitious black surface at ambient temperature. Double distribution functions (D2Q9-D2Q4) with different relaxation times are used to predict dynamic and thermal fields. Influence of surface radiation, operating temperature, inclination angle and aspect ratio on heat losses from the hot wall inside the cavity is analyzed and discussed. It was found that convective heat loss is largely increasing by increasing the inclination angle. Concerning surface emissivity effect, an amplification by coefficient of 4 between ε = 0.2 and ε = 1.0 is accomplished for thermal radiation heat loss whereas convective heat loss is marginally reduced. It was also found that total heat loss from the cavity absorber is influenced by operating temperature and aspect ratio. In fact, increasing of operating temperature enhances heat loss while the increasing of aspect ratio reduces it.

2024, Renewable Energy

In this paper, a new, ray-tracing, optimization for the design of secondary reflectors for linear Fresnel collectors is presented. Optimization is capable to produce the optimum shape of the reflector, by tailoring properly oriented segments, so that the maximum concentration of off-target rays is redirected back to the cylindrical receiver. As an illustrative example, it is applied to the design of the secondary reflector for an existing installation. The shapes of the secondary reflectors are different for the different vertical distances from the receiver. The optical performance of the various configurations is investigated by utilizing free, open source ray-tracing software. The maximum value of successful rays ratio, i.e. the fraction of sun rays that intersect the receiver, reaches 0.97 and 0.84, for secondary reflectors located 5 and 12.5 cm above the receiver, respectively.

2024, Energy

This paper presents results of a numerical analysis of entropy generation in a parabolic trough receiver at different concentration ratios, inlet temperatures and flow rates. Using temperature dependent thermal properties of the heat transfer fluid, the entropy generation due to heat transfer across a finite temperature difference and entropy generation due to fluid friction in the receiver has been determined. Results show a reduction in the entropy generation rate as the inlet temperature increases and an increase in the entropy generation rate as the concentration ratio increases. Results further show that, there is an optimal flow rate at which the entropy generated is a minimum, for every combination of concentration ratio and inlet temperature. The optimal flow rates at which the entropy generated is minimum are 11.974×10-3 , 15.395×10-3 , 18.817×10-3 , and 22.238×10-3 and 25.659×10-3 m 3 /s when the concentration ratio is 40, 60 80 100 and 120 respectively, irrespective of the inlet temperature considered. For the range of inlet temperatures, flow rates and concentration ratios considered, the Bejan number, which measures the contribution of entropy generation due to heat transfer irreversibility to the total entropy generation rate is about 1 at low flow rates and is between 0-0.24 at the highest flow rate.

2024, Elektronika ir Elektrotechnika

The increased rate of energy crises around the world results in expanding the role of Concentrating Solar Power (CSP) technology for different applications, comprising heating process and power generation applications. The Parabolic Dish Concentrator (PDC) with its large concentration ratio and its modular capacity attracts researchers’ efforts. In this research work, we have designed and developed a PDC with back silvered mirrors as reflector material. Then we have sized the following geometric parameters: the dish diameter, the focal length, the aperture area, the rim angle, the geometric concentration ratio, the receiver material, and the receiver diameter. Furthermore, a dual-axis manual tracking system has been built for this PDC. It should be mentioned that the different components of the PDC have been recycled from a scrap yard to develop a low-cost PDC system. Finally, we have investigated the temperature evolution as a function of time at the focus spot. The maximum tempera...

2024, International journal of engineering sciences

Abundant solar energy is freely available almost round the year in India. As per the current scenario of global warming and climatic change, solar energy is the cleanest source in nature. Concentrated solar power (CSP)has hardly contributed to the overall installed solar power capacity in the country. CSP technologies are Parabolic Trough Collector (PTC), Linear Fresnel Reflector (LFR), Paraboloid Dish and Solar Power Tower. This paper presents a review of CSP in solar parabolic dish concentrator to understand thermal aspect like thermal efficiency, optical efficiency, useful heat gain, heat losses, solar irradiation, etc. for various applications and current development. The current scenario of global CSP is discussed to meet the future challenges and need of the society.

2024

The paper presents a physical and mathematical model of the new offset type parabolic concentrator and a numerical procedure for predicting its optical performances. Also presented is the process of design and optical ray tracing analysis of a low cost solar concentrator for medium temperature applications. This study develops and applies a new mathematical model for estimating the intercept factor of the solar concentrator based on its geometrical and optical behavior. The solar concentrating system consists of three offset parabolic dish reflectors and a solar thermal absorber at the focus. Two types of absorbers are discussed. One is a flat plate circular absorber and the other a spiral smooth pipe absorber. The simulation results could serve as a useful reference for design and optimization of offset parabolic concentrators.

2024, Journal of Fundamental and Applied Sciences

The Parabolic trough solar collector is considered as one of the most proven, mature and commercial concentrating solar systems implemented in arid and semi-arid regions for energy production. It focuses sunlight onto a solar receiver by using mirrors and is finally converted to a useful thermal energy by means of a heat transfer fluid. The aims of this study are (i) to develop a new methodology for simulation and performance evaluation of parabolic trough solar collector, in addition (ii) to compare the efficiencies of this system using two different fluids; thermic oil and molten solar salt. The validation of obtained results using this methodology shows a good agreement with those obtained by the experimental tests. Furthermore, this study favors the using of thermic oil as heat transfer fluid in the receiver instead of molten salt due to the high efficiency of the concentrator based on the first fluid in comparison to the second one.

2023, Mediterranean Journal of Modeling and Simulation

L'objectif du present travail est de caracteriser une centrale a concentrateur de Fresnel de moyenne puissance (5MWe) sur differents sites Algeriens (Sahara), ces sites ont ete choisis pour comparaison en deplacant la centrale dans ces derniers, a savoir Hassi-R'mel, Tamanrasset, Beni-Abbes, et El Oued. Une modelisation theorique a permis la determination du nombre optimum des miroirs a ne pas depasser pour eviter les effets d'ombre, blocage et l'effet cosinus. Le nombre optimum de miroirs a ete estime a (...)

2023, Applied Thermal Engineering

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2023, ASME open journal of engineering

Concentrated solar power presents immense scope for the deployment of small-scale units focusing on diverse applications, including process heat and rural on/off-grid applications. This paper presents the analysis of solar irradiance variation on heat flux and temperature distribution at the dish concentrator receiver. A solar dish concentrator with a 2.8-m aperture diameter and a 0.4-m depth was used for this analysis. The solar ray intersection between a dish concentrator and its receiver, along with the heat flux distribution prediction, was carried out using SolTrace. The effect of flux intensity variation on temperature distribution at the receiver was investigated using COMSOL MULTIPHYSICS. The optical analysis considered 10,000 rays, and 91.65% of them were observed to reach the surface of the receiver. For 1000 W/m 2 of beam solar radiation, a peak heat flux and maximum temperature at the concentrator's focal plane are found to be 32.4 MW/m 2 and 923 K, respectively. The validation had been done using previously reported results in the literature to verify the correctness of the present simulation results. The effect of beam solar radiation variation on heat flux intensity and the temperature distribution revealed that both heat flux and temperature increase with increasing solar radiation, which points out the influence of design and operating conditions. Apart from PillBox and Gaussian distributions, the effect of slope and specularity errors was characterized, suggesting a greater sensitivity to the former than the latter.

2023, Applied Sciences

A parabolic solar dish concentrator, as the heat source of an organic Rankine cycle (ORC), can be used for power generation. Different types of tubular cavity receivers with different nanofluids can be considered for use in the solar dish collector to improve its efficiency. In the current research, an ORC with three different cavity receivers including hemispherical, cubical, and cylindrical are investigated using three nanofluids: Al2O3/oil, CuO/oil, and SiO2/oil. A numerical model is validated using experimental data. The ORC analysis is done for a constant evaporator pressure of 2.5 MPa, and condenser temperature of 38 °C. Methanol is employed as the ORC’s working fluid and a non-regenerative, ideal ORC system with different turbine inlet temperatures is considered. Furthermore, a fixed solar heat transfer fluid flow rate of 60 mL/s and dish diameter of 1.9 m is investigated. Results show that, compared to pure oil, the thermal efficiency of the cavity receivers increases slight...

2023, Journal of Cleaner Production

Solar concentrating technologies can produce heat for applications such as solar heating, solar cooling, industrial processes, desalination and electric power generation. For a solar dish collector, various solar receivers and working fluids at different flow rates can be used in different applications. In this work, three different cavity receivers are investigated for application in a solar dish collector using either water or Behran oil. A numerical model is used in the analysis, which is validated with experimental results from a hemispherical cavity receiver using oil as working fluid. The model is applied to compare hemispherical, cylindrical and cubical receivers under the same operating conditions using either water or oil, at a volumetric flow rate of 100 ml/s and solar irradiance of 800 W/m 2 , in order to determine the most suitable cavity for a specific solar dish. The system is investigated for inlet temperatures ranging from 40 o C to 90 o C with water as working fluid, and from 40 o C to 300 o C with Behran oil as working fluid. Emphasis is placed on the calculation of useful heat production, as well as pressure drop which influences pumping power. The exergetic efficiency criterion and the overall efficiency criterion are used in order to evaluate the useful heat production and the pumping power simultaneously. The high exergetic efficiency of the hemispherical cavity with thermal oil at high temperatures makes this case a promising choice for high-temperature solar dish collector applications. Moreover, water is found to be the best candidate for low-temperature applications since it leads to higher thermal efficiency with lower pumping power demand.

2023, Mechanics & Industry

In this study, the thermal performance of a parabolic dish concentrator with a rectangular-tubular cavity receiver was investigated. The thermal oil was used as the working fluid in the solar collector system. The performance of the cavity receiver was studied in two ways as a numerical modeling method and the artificial neural networks (ANNs) methodology. In this study, three variable parameters including the different tube diameters equal to 5, 10, 22, and 35 mm, and different cavity depths equal to 0.5a, 0.75a, 1a, 1.5a, and 2a were considered. The purpose of this study is the prediction of the thermal performance of the cavity receiver in different amounts of solar irradiance, the cavity depth, and the diameter of tube by the ANN methodology. The main benefit of the ANN method, in comparison with the numerical modeling method, is the calculation time and cost saving. The results reveal that the ANN method can accurately predict the thermal performance of the cavity receiver at different variable parameters of the cavity depth, and tube diameter with R 2 = 0.99 for each prediction.

2023, Proceeding of Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017)

The share of solar thermal energy for process heat at sub cooled temperature is estimated about 30% of the total demand. The assessment of heat loss from tubular receiver used for the process heat is necessary to improve the thermal efficiency and consequently the cost effectiveness of the parabolic dish receiver system. The study considers a modified three coil solar cavity receiver of wall area three times (approximately) as compared to the existing single coil receiver and experimentally investigates the effect of increases in cavity inner wall area, fluid inlet temperature (50-75 ºC), and cavity inclination angle (θ = 0-90º) on the combined (total) heat loss from receiver under no wind condition. This paper also develops an analytical model to estimate the different mode of heat losses from the downward facing receiver. In the mean fluid temperature range of 50 ºC to 70 ºC, the total heat loss from three coil receiver is reduced up to 40.98% at 90º and 20% at 0º inclination, as compared to single coil receiver. The analytical modeling estimates very low heat loss from conduction (1-3%) and radiation (2-8%) and high heat loss from convection (97-89%). The heat loss by natural convection decreases sharply with increase in cavity inclination, while the heat loss by radiation and conduction increases slowly with inclination. A three coil cavity receiver might be considered in the design to reduce heat loss from parabolic dish receiver system to improve the thermal performance and cost effectiveness.

2023, Renewable Energy and Power Quality Journal

The radiation performance of a modified cavity receiver for a low-cost concentrating solar power plant is studied. The optical phenomenon taking place is modelled by using a ray tracing technique based on a finite element approach. This design is also compared to a flat receiver. Corrections for sunlight and optical errors of the parabolic dish are included. Its efficiency is analysed by varying some geometrical parameters of the receiver, maximizing the total power absorbed. It is found that the flux density on the cavity walls is less than on the flat receiver walls, hence decreasing heat losses. Also, in order to reach a maximum radiation performance the receiver is to be placed closer to the concentrator from the focal position. However, the aperture does not improve notably its efficiency, although it has an important role in the convection heat losses as shown in previous works. Finally by varying the cavity diameter it is possible to improve the efficiency when it is well adjusted to the radiation performance of the concentrator on the focal point.

2023

2023, International Journal of Renewable Energy Development

Energy consumption has increased withthe population increase, and fossil fuel dependency has risen and causing pollutions. Solar energy is suitableto provide society's thermo-electric needs. Thermal energy storage-based concentrated solar receivers are aimed at store heat energy and transportable to the applications. Acavity receiver with two-phase change materials (PCM) is experimentally investigated using a parabolic dish collector to act as the solar heat battery. The selected PCMs are MgCl2.6H2O and KNO3-NaNO3. PCMs are chosen and placed as perthe temperature zones of the receiver. The outdoor test wasconductedto determine the conical receiver's storage performance using cascaded PCMs. The complete melting of PCM attainsat an average receiver surface temperature of 230°C. The complete melting of the PCM in the receiver took around 30 minutes at average radiation around 700 W/m2, and heat stored is approximately 5000 kJ. The estimated number of cavity receivers to be char...

2023, Applied Thermal Engineering

Stirling engine operated by concentrated solar energy can be a great mean to generate power. Highly concentrated solar radiations with minimum heat loss from cavity receiver are required to operate the Stirling engine. Therefore, heat transfer study of the cavity receiver is required for the maximum utilization of solar energy with minimum heat losses for the efficient Stirling engine generator. In this study, experiments were performed to find the most suitable cavity receiver configuration for maximum solar radiation utilizations by an Advanced Stirling Engine Generator (ADSEG). Dimensionless parameter: aperture ration (AR = d/D) and aperture position (AP = H/D) were used to characterize the different configurations of cylindrical cavity receiver. Experimental heat loss analysis (Convection, radiation and total heat loss) as well as air film temperature profiles along the wall height (H) of the receiver for different configurations of the cavity receiver was performed in this experiment for its selection. Based on experimental results, among the four different configurations of cylindrical cavity receiver, Type IV (AR = 0.5 AP = 0.53) was found to be the most suitable receiver for the ADSEG system.

2023, MATEC Web of Conferences