Fresnel Solar Concentrator Research Articles

Effect of solar powered MgO/graphene nano catalysed biodiesel production from Scomber scombrus

The aim of the work is to find the efficiency of solar power in biodiesel preparation from mackerel fish. The paper also focusses on the ability of MgO/graphene prepared by one-pot synthesis using combustion methodology. The physicochemical properties of the material were analysed by XRD, N2 sorption studies, BET sorption analysis and SEM. The adsorption studies revealed the porosity of the graphene is intact, and the morphology studies indicated that MgO is uniformly distributed on the graphene surface. The highest biodiesel yield of 98.95% was obtained using the solar-powered Fresnel solar concentrator at 12.30 p.m in 6 min reaction time using 3 wt% MgO/GO catalyst at 65 °C. Conventional heating produced only 75% biodiesel at the same reaction condition, consuming25 min to complete. The solar assisted biodiesel had better HHV of 37.81 MJ/Kg, viscosity of 4.3 mm2/s, pour point of −15 °C, and a density of 0.875 g/mL. The optimized catalyst showed a shelf life of 5 cycles. The results portray the efficacy of natural energy source in alternative liquid fuel production.

On the comparison of parabolical and cylindrical primary mirrors for linear Fresnel solar concentrators

On the comparison of parabolical and cylindrical primary mirrors for linear Fresnel solar concentrators

Thermographic image processing analysis in a solar concentrator with hard C-means clustering

Thermographic measurements are used to determine the temperatures reached by the focus of a modified Fresnel solar concentrator, where a container is placed to take advantage of this energy. The three steps of this investigation are: (i) the edges of each thermographic image are obtained by means of a Butterworth low-pass filter, (ii) the temperature grid in the solar concentrator is obtained by means of a feature extraction algorithm, and finally: (iii) the classification will be done through a C-means hard clustering algorithm selecting the center of each cluster to accurately find the temperature region to generate the isotherms and extract the temperatures with this algorithm. With the hard C-means algorithm, isotherm level curves and temperature graphs are obtained. Subsequently, two analyzes are carried out to validate that the original unprocessed thermographic images correspond spatially and in their spectrum with the processed images, with the aim of corroborating the acuteness of the digital image processing methodology implemented in this research. Finally, a correlation analysis is performed to validate the temperature matches of the original thermographic images.

Investigation The performance of a Linear Fresnel Solar Concentrator Integrated with an Adsorption Refrigeration Cycle

A large amount of the energy produced is used for heating and cooling application. Many studies at the present time are looking for ways to reduce this consumption or use a renewable energy source to reduce dependence on fossil fuel energy. In this research, the used of solar energy to power a hybrid adsorption ice-maker, a linear Fresnel solar concentrator type, with a total area of 5 m2, is used for this purpose The concentrator was designed, built and conducting an experimental study in Baghdad (latitude 33.33 and longitude 44.14) for the solar system that which is consisting of the concentrator with a double absorber type evacuated tube has been used, tank, pump and accessories to investigate the performance of the system and the effect of the water flow on the unit performance. The performance of the adsorption system is studied theoretically. The adsorption system works with the activated carbonmethanol pair the mass of activated carbon is 0.5 and while the mass of methanol is 1.6 kg. The experimental work was achieved at July 2019 and the results showed that the maximum temperature of the water inside the tank obtained was 95 °C when the rate of water flow through the collector loop was 0.5 kg/min and that the maximum thermal efficiency was about 40% at the same flow amount. The theoretical results showed that the best coefficient of performance for the adsorption refrigeration system was 0.43 at the generator temperature of 95 °C and the condensing temperature of 30 °C.

Experimental study of a linear Fresnel concentrator: A new procedure for optical and heat losses characterization

This paper describes a set of iterative procedures developed in Matlab and Engineering Equation Solver, used to experimentally obtain the optical and heat loss characterization of a small-scale linear Fresnel concentrator. These procedures were created for a prototype designed and built for direct steam generation by the LEPTEN laboratory, at the Federal University of Santa Catarina. Two different sets of experimental data were considered. First, the heat transfer fluid was at the lowest temperature achievable using the experimental setup available and was used to obtain the optical peak efficiency and the incidence angle modifier. The second set, with wider range of fluid temperatures, was used to find the heat losses. Applying the procedures developed, convergence was obtained. The optical peak efficiency ranged from 47 to 52%. Monte Carlo Ray-Tracing software was used to obtain the incidence angle modifier, and these curves were compared with experimental ones. The heat loss curve was constructed for fluid temperatures up to 130 °C. These iterative procedures can be adapted to determine the heat loss and optical efficiency in any linear Fresnel solar concentrator if adequate experimental data is available. Each software used had its role, and the use of both allowed creating a fast easy-to-converge methodology.

Research on the Performance of Solar Aided Power Generation System Based on Annular Fresnel Solar Concentrator

A solar-aided power generation (SAPG) system effectively promotes the high efficiency and low cost utilization of solar energy. In this paper, the SAPG system is represented by conventional coal-fired units and an annular Fresnel solar concentrator (AFSC) system. The annular Fresnel solar concentrator system is adopted to generate solar steam to replace the extraction steam of the turbine. According to the steam–water matrix equation and improved Flugel formula, the variable conditions simulation and analysis of the thermo-economic index were proposed by Matlab. Furthermore, in order to obtain the range of small disturbance, the method of partial replacement is used, that is, the extraction steam of the turbine is replaced from 0 to 100% with a step size of 20%. In this work, a SAPG system is proposed and its thermo-economic index and small disturbance scope are analyzed. The results show that the SAPG system is energy-saving, and the application scope of small disturbance is related to the quantity of the extraction steam and evaluation index.

The effect of glass on the receiver and the use of two absorber tubes on optical performance of linear fresnel solar concentrators

The optical analysis of any reflector of sunrays is a major task, because it is never easy to predict the quantity and the quality of the solar flux radiation falling on a receiver. Two algorithms can be used for the calculation of the flux distribution and thus temperatures in the receiver, namely, the Ray-Tracing and cones optics methods. We propose for the optics of the Fresnel concentrator a modeling and numerical simulation of the optical performances of Fresnel’s type solar field based on Monte Carlo ray-tracing (MCRT). This article presents an optical optimization of a solar prototype with Fresnel type concentration. This optimization was carried out through a parametric study, and a dimensioning calculation to determine the influence of each parameter on performance i.e the impact of the glass and the impact of the geometry of the receiver. The analysis of the results presented in the form of tables and curves allowed us to determine the optimal configuration of our solar prototype. This configuration gives better theoretical and experimental performances. On the basis of this optimal configuration, several thermal power stations based on LFR technology have been built and marketed. As well, several numerical models have been verified and validated through the usage of highly developed and very reliable measuring instruments. The removal of the glass resulted in an estimated gain in annual optical efficiency of 5.6% (from 40.49% to 42.75%). The use of two absorber tubes resulted in an annual gain in optical efficiency estimated at 15.5% (from 40.49 to 46.79%).

Design and test of an annular fresnel solar concentrator to obtain a high-concentration solar energy flux

For covering some shortcomings of the traditional high concentrated solar concentrator, Annular Fresnel solar concentrator coupled with a circular Fresnel lens (AFSCFL) is developed and studied in the study. The AFSCFL mainly consists of an Annular Fresnel solar concentrator (AFSC), one circular Fresnel lens and a receiver. The AFSC was constructed by a series of annular mirrors. The circular Fresnel lens is located at the center of the AFSC. Simulation studies were performed between the AFSCFL and the AFSC. The results showed that average radiation, maximum radiation, and solar power on the receiver of the AFSCFL were 9.49%, 10.70%, and 9.49% higher than the AFSC. Besides, a test bench was designed and constructed to investigate the solar collecting performance of the AFSCFL. The comparisons experiments of variable flow and constant flow on the AFSC and AFSCFL were carried out. The results showed that in the low solar radiation condition the thermal efficiency of the AFSCFL could be 20% higher than that of the AFSC. In the high solar radiation condition, the thermal efficiencies of the AFSCFL and the AFSC were similar. This AFSCFL has excellent heating collect performance under this initial test bench.

Design and performance analysis of an annular fresnel solar concentrator

In this paper, an annular Fresnel solar concentrator (AFSC) is proposed. This novel concentrator was incorporated with a series of annular mirrors, and its performance was simulated using MATLAB software. The influences of different structures were also simulated. The tracking deviation, device deviation, and comprehensive deviation were analysed using different deviation angles. The results demonstrated that this concentrator could simply adjust the concentrating ratio, which reached 300 when the maximum concentrator height was 0.78 m and the maximum diameter was only 1.72 m. Non-linear changes in the performance of the annular Fresnel reflector occurred when the structure size increased linearly. Further, the radiation distribution and performance of the annular Fresnel reflector were found with different deviations. When the tracking deviation angle was 0.5°, the receiving rate was 98.37%. This new AFSC has excellent concentrated solar power (CSP) application prospects.

A testbed of intelligent sun tracking system and thermoelectric generator with Fresnel lens at solar cell system for maximizing generated energy

Solar or photovoltaic cells are one of the most potent renewable technologies to be applied in Indonesia that have a relatively high average daily solar radiation rate of 4.5 kWh/m2/day. In conventional applications, solar cells still have some weaknesses, especially on the efficiency of output that only reaches in the range of 5—16%. In this paper, optimizing the production of electrical energy in conventional solar cell system is carried out by modifying the system construction and controller. Intelligent Mobile Thermophotovoltaic (IMT) is a modified solar cell system that combines utilization of two sources of solar energy that are photon and thermal energy to convert into electrical energy. The sollar panel is intelligently controlled to maximized the received sunlight in solar cell. Fresnel lens is utilized for supporting the thermal energy collection of sunlight on the solar cell. The total energy produced by IMT is energy from Fresnel solar tracking concentrator plus the energy from thermoelectric heat collector and subtracted by energy which used for tracking system of about 2 Wh. The IMT can yield the electrical power of 91.815 Wh while the conventional solar cell system brought 55.15 Wh for 8 operation hours. This result showed that IMT can raise 66.46% the electrical energy production of conventional solar cell system.

Analysis on an optimal transmittance of Fresnel lens as solar concentrator

This paper presents a novel method approaches to simplify refractions on prisms to get the ideal shape of the Fresnel lens. A simplification is about to use one refraction on the upper surface to replace the two refractions on the upper and the lower surfaces. A differential equation that describes the ideal shape of Fresnel lens has been derived out. It shows that the particular solution of the differential equation is a bunch of confocal curves. Especially, the ideal curves are closing to their basic circle when total refracted angle less is than 30°, which makes it reasonable to use the basic circle as the profile of Fresnel lens. Then a Fresnel lens was designed with considering material and manufacturing technology. Then an analysis on the focal length change during the tilt incidence was mainly carried via simulation and experiment. It is found that the effective tilt incident angle can be enhanced from 7° to 32° by lifting up the position of the receiver and adding a simple mirror secondary reflector. The experimental result shows that the Fresnel solar concentrator is working efficiently during the time from about 10:00 to 14:30 a day. The steady output temperatures are 125 °C, 150 °C and 170 °C, with collection efficiencies are about 0.53, 0.48 and 0.44. It can well satisfy mid-temperature solar thermal application.

Design and development of small-scale linear Fresnel solar concentrator for medium temperature applications

In recent years, Even if the CSP industry (Concentrated Solar Power) has not been yet developed as it should be in Morocco, this country is attaching an increasing importance and have launched ambitious development goals by the year 2020. Many applications of CSP technology needs operating temperatures up to 300 °C [1]. These applications include water heat especially for domestic needs.The present article shows the results of a work about the development of a low-cost concentrator taking into account Moroccan socio-economic context. The system designed and developed a combination uses of two CSP technologies: Parabolic Dish and Linear Fresnel Concentrator. To develop the prototype, a simplified model was used to define the dimensions as well as the number of mirrors that compose the system. The system is autonomous, modular and makes it possible to concentrate the solar radiation with automatic tracking of the sun. A set of mirrors focus sunlight onto a fixed absorber located at a common focal point which is adjustable and allows connecting different types of absorbers. This paper is detailing the design of the devloped prototype. The system is innovative and operates at temperatures up to 250 °C. It is easy to meet the household hot water needs as per Moroccan natural conditions.The paper describes the modelling approach, presents the comparison of simulation results with real measurements and evaluates the results.

Application-based design of the Fresnel lens solar concentrator

A novel genetically themed hierarchical algorithm (GTHA) has been investigated to design Fresnel lens solar concentrators that match with the distinct energy input and spatial geometry of various thermal applications. Basic heat transfer analysis of each application decides its solar energy requirement. The GTHA incorporated in MATLAB® optimizes the concentrator characteristics to secure this energy demand, balancing a minimized geometry and a maximized efficiency. The optimum concentrator is then simulated to ensure the algorithm validity. To verify the algorithmic-optimization and simulation-validation processes, two experimental applications were selected from the literature, a solar welding system for H13 steel plates and a solar Stirling engine with an aluminum-cavity receiver attached to the heater section. In each case, a flat Fresnel lens with a spot focus was algorithmically designed to supply the desired solar heat, and then a computer simulation of the optimized lens was conducted showing great comparability to the original experimental results.

Multi-wavelength multi-focus Fresnel solar concentrator with square uniform irradiance: design and analysis.

In this paper, a two-step optical design method is proposed to build a superior Fresnel-based photovoltaic concentrator for enhancing light conversion efficiency with the multi-junction solar cell. In the first step, we orthogonally segment a traditional Fresnel concentrator and remove the two normal stripe bands around the horizontal and vertical axes, as well as recombine the resultant four quadrants again. By using such a specific Fresnel concentrator design, a square light pattern can be constructed owing to the off-axis non-rotational symmetric superposition of light. In the second step, as for the response wavelengths of a specific triple-junction solar cell, we further carry out a triple-wavelength and multi-focus design of the above Fresnel concentrator for improving the uniformity of light distribution on the solar cell. To show the validity of this novel design method, a solar concentrator, with typical design parameters including the geometrical concentration ratio of 800× and the F-number of 0.775, is designed and simulated. As a result, theoretical irradiance uniformity up to 87% is obtained. In addition, considering the fact that no second optical element is involved in the concentrator system, our design method inherently has the advantages of good compactness, high efficiency, low cost, and ease for mass-production. We believe that such a concentrator is of great significance to solar cells for high conversion efficiency of light in the concentrator photovoltaic system.

Theoretical performance analysis of new class of Fresnel concentrated solar thermal collector based on parabolic reflectors

The main advantage of Fresnel systems is their capability to use flexible reflectors which are cheaper in comparison to glass reflectors. In this study, the effects of using parabolic reflectors instead of flat reflectors on Fresnel solar concentrator have been studied for the first time. For this new system by ray trace statistical method, local concentration ratio distribution has been determined. The new system is compared with linear Fresnel reflector (LFR). The effect of geometrical parameters, such as absorber height and reflectors width, on the concentration ratio is studied. The results have shown that using the parabolic reflectors with low curvature has a pronounced effect on the absorber pipe diameter. Comparison of the performance of linear and parabolic systems with identical parameters such as reflectors width, reflectors number and absorber pipe height showed that the absorber tube diameter in a parabolic system is smaller than the absorber tube diameter in a linear system, thus decreased rate of heat loss from the pipe surface. Comparison of the two systems under equal solar energy radiation and absorber pipe diameter showed that in parabolic system wider reflectors can be used, thus reduced number of reflectors and simpler control system.

Thermodynamic Analysis of a Solar Combined Ejector Absorption Cooling System

The objective of this paper is to investigate theoretically a solar driven 60 kW absorption cooling system. The system is constituted of a combined ejector single-effect absorption cycle coupled with a linear Fresnel solar concentrator and using water/lithium bromide as working fluid. The combined ejector single-effect absorption cycle exhibits high performances, almost equal to that of double-effect absorption device. However, higher driving heat temperatures are required than in the case of conventional single-effect machines. A mathematical model is set up to analyze the optical performance of the linear Fresnel concentrator. Simulations are carried out to study the overall system performance COPsystem and the performances of the combined absorption machine COPcycle for generator driving temperatures and pressures in the ranges 180°C – 210°C and 198 kPa – 270 kPa, respectively. Further, the effect of operating parameters such as the cooling medium and chilled water temperatures is investigated. A maximum cycle performance of 1.03 is found for a generator pressure of 272 kPa and chilled and cooling water temperatures of 7°C and 25°C, respectively. A case study is investigated for a typical summer Tunisian day, from 8:00 to 18:00. The effect of ambient temperature and solar radiation on cycle and system performances is simulated. The optical performances of the concentrator are also analyzed. Simulation results show that between 11:00 and 14:00 the collector efficiency is 0.61 and that the COPcycle reaches values always higher than 0.9 and the COPsystem is larger than 0.55. Globally the performances of the investigated cycle are similar to those of double-effect conventional absorption system.

Parametric investigation of thermal characteristic in trapezoidal cavity receiver for a linear Fresnel solar collector concentrator

Solar collectors—especially Linear Fresnel Reflectors—are one of the main implements to utilize the energy of sun light. The receiver cavity of the collector is recognized as an important component of each concentrating solar power plant. In this study, the heat transfer rate and heat loss in a trapezoidal cavity of the linear Fresnel reflector are analyzed. The calculations are performed for steady-state, laminar model in which temperature-dependent density is assumed for the air inside the cavity. The effects of the cavity angle and the effect of the tube size are evaluated, in various models. DTRM radiation model is employed for the simulation, while considering radiation, conduction and convection heat transfers are as the boundary conditions. Finally, it will be observed that by increasing the cavity angle, the total value for heat transfer rate is increased, but the heat absorbed by each tube is decreased. The results also show that the tube size is less effective on heat transfer rate compared to the cavity angle.

Modeling and experimental evaluation of a small-scale fresnel solar concentrator system

The purpose of this study was to evaluate the overall effectiveness of a small-scale, low cost, versatile solar concentrator suitable for the needs of single individuals. The system consisted of a spot-type fresnel lens, and a solar absorber sized for moderate temperature range (80–250 °C) applications. Simple and inexpensive materials were chosen for the construction of the tracking system, frame, and absorbers. The thermodynamic properties of the system were determined from theoretical and experimental estimates of temperature and pressure. Efficiencies as high as 50 % were estimated form irradiance and heat losses measurements. The study proved the feasibility and cost effectiveness of the small-scale solar concentrator prototype for varied applications such as boiling water, solar cooking, and autoclaves.

Performance investigation of a concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator

A design method of a cycloidal transmissive Fresnel solar concentrator which can provide a certain width focal line was presented in this study. Based on the optical principle of refraction, the dimensions of each wedge-shaped element of Fresnel lens are calculated. An optical simulation has been done to obtain the optical efficiency of the concentrator for different tracking error and axial incidence angle. It has been found that about 80% of the incident sunlight can still be gathered by the absorber when the tracking error is within 0.7°. When the axial angle of incidence is within 10°, it almost has no influence to the receiving rate. The concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator has been designed in this paper. Take the gallium arsenide high concentrated battery as the receiver, experimental research about cylindrical Fresnel concentrating photovoltaic/thermal system is undertaken in the real sky. Main parameters are tested such as the temperature distribution on receiver, electric energy and thermal energy outputs of concentrating photovoltaic/thermal system, the efficiency of multipurpose utilization of electric and heat, and so on. The test results in clear weather show that maximum electric generating efficiency is about 18% at noon, the maximum heat receiving rate of cooling water is about 45%. At noon time (11:00–13:00), the total efficiency of thermal and electricity can reach more than 55%. Performance of this concentrating photovoltaic/thermal system with transmissive Fresnel solar concentrator is studied and compared in two types typical weather, hazy weather and clear weather, it can be known from results that hazy weather has great influence to electric generation efficiency but it has less effect to heat efficiency of cooling water.

Optical Simulation and Experimental Verification of a Fresnel Solar Concentrator with a New Hybrid Second Optical Element

Fresnel solar concentrator is one of the most common solar concentrators in solar applications. For high Fresnel concentrating PV or PV/T systems, the second optical element (SOE) is the key component for the high optical efficiency at a wider deflection angle, which is important for overcoming unavoidable errors from the tacking system, the Fresnel lens processing and installment technology, and so forth. In this paper, a new hybrid SOE was designed to match the Fresnel solar concentrator with the concentration ratio of 1090x. The ray-tracing technology was employed to indicate the optical properties. The simulation outcome showed that the Fresnel solar concentrator with the new hybrid SOE has a wider deflection angle scope with the high optical efficiency. Furthermore, the flux distribution with different deviation angles was also analyzed. In addition, the experiment of the Fresnel solar concentrator with the hybrid SOE under outdoor condition was carried out. The verifications from the electrical and thermal outputs were all made to analyze the optical efficiency comprehensively. The optical efficiency resulting from the experiment is found to be consistent with that from the simulation.