Solar Parabolic Dish Collector Research Articles

Numerical and experimental analysis of a cross-finned solar receiver for parabolic dish collectors

A parabolic dish solar collector (PDC) is used to concentrate solar radiation on a receiver to produce hot water or steam for various thermal applications. The solar receiver of the PDC is one of the significant components to improve the overall efficiency of the PDC. The present study is a numerical and experimental investigation of the thermal performance of a solar receiver with vertical fins with and without cross fins. The fin orientation was investigated using 0.056 kg/s, 0.083 kg/s, and 0.111 kg/s water flow rates. COMSOL Multiphysics® was used to simulate the receiver to determine the receiver’s temperature behavior. The thermal performance parameters such as heat gain, heat loss, convective heat transfer coefficient, and thermal, and exergy efficiency were analyzed under various flow conditions. The cross fins effectively prolong the water residence, increasing turbulence, and heat transfer and reducing heat loss to the surroundings. The receiver with cross fins at higher flow rate conditions shows higher thermal performance than lower flow rate and without fins conditions. The solar radiation during the outdoor testing is in a range of 300–950 W/m2 and the ambient temperature varies from 30-37 °C. The peak average thermal and exergy efficiency obtained for the cross-finned receiver at 0.111 kg/s is 64.4 %, and 6.3 %, respectively. Cross-finned receiver operating at 0.111 kg/s reduced CO2 mitigation rate, estimated at approximately 0.29 tons of CO2 per year, along with a lower carbon credit gain at $0.47. Thus, the proposed cross-fin solar receiver demonstrates improved thermoeconomic performance than conventional receiver designs, offering a more cost-effective design with minimal investment.

Numerical investigation to optimize the modified cavity receiver for enhancement of thermal performance of solar parabolic dish collector system

The concentrated parabolic dish collector (PDC) systems are widely utilized for the purpose of generating high-temperature heat by receiving and converting solar energy efficiently into thermal energy. Cavity receivers including spiral coils have a common use in PDC system for optimal thermal performance. Therefore, to enhance the thermal performance of a PDC system, the present study investigates different cavity receiver configurations, such as cylinder and conical shaped receivers with flat and spherical absorber surface as well as the effect of spiral coil arrangement. To identify the most optimal spirally coiled cavity receiver, the comparison is conducted based on outlet temperature, heat exchange rate, thermal efficiency, effectiveness, and thermal performance capability (TPC). The investigations were conducted using the ANSYS Fluent CFD simulation software package. The SolTrace software package was utilized to compute the maximum heat flux incident on the absorber surface of the receiver, and peak heat flux data was used as input parameter at the absorber surface of the receiver. Furthermore, to select the suitable working fluid in PDC system, different heat transfer fluids, such as Syltherm 800, Xceltherm 600, ParathermHR™ and water, respectively were studied. From the thermal analysis of various proposed receiver geometries, the receiver with conical shape and spherical absorber surface is more efficient over other configurations. It provides 50 % higher heat transfer rate thancylindrical receiver with flat absorber surface. Moreover, receiver's thermal performance could modestly be improved by modifying the spiral coil pitch (variable pitch). In terms of pumping power consumption, readily availability, low viscosity, and high specific heat, water is suggested as working fluid for receiver of PDC system.

Optical and thermal investigation of hyperbolic cavity receiver with secondary reflector for solar parabolic dish collector

A hyperbolic-shaped cavity-type receiver with a second stage reflection for a 40 m2 solar parabolic dish concentrator (PDC) is presented in this paper,along with optical and thermal modeling. The receiver geometry and the secondary reflector complete the hyperbolic geometrical shape of the present receiver. This study aims to estimate heat losses owing to natural convection and radiation under influential parameters associated with solar parabolic dish system. Optical modeling has been performed with verified model using ASAP® 2013 V1R1. The optical simulations have been carried out for varying receiver height (h1), height of the secondary (h2) and diameter-to-total height ratios (d/h) of 0.5, 1, and 1.5 while keeping the diameter of the plane aperture of the receiver (d) constant. The optimum receiver geometry has been selected based on the performance in terms of optical efficiency. The maximum efficiency found is 91.72% for h1 = 0.75 m and d/h = 0.5 for the mounting distance of 4.21 m. The optimized shape is further studied to determine how the receiver absorptivity and the secondary reflector's reflectivity affect the optical performance. The absorptivity and reflectivity range from 0.86 to 0.94. Obtained optimum receiver geometry from the optical investigation is further analyzed to estimate the heat transfer rate. The thermal modeling is performed for 0°, 30°, 60°, and 90° orientations of the receiver in ANSYS Fluent 2020 R1. A comprehensive comparison among the available models has been reported and validated with well-established experimental data. This work has developed free convective Nusselt number correlation. It can be a valuable addition to the existing literature.

Numerical and experimental analysis on convective heat losses from a fully open cylindrical cascaded cavity receiver

A cavity receiver finds substantial application to improve the thermal performance of a solar parabolic dish collector. However, its limited surface area shortens the scope of utilization and bars thermal efficiency. This research has intercepted such problems by including a cascaded cavity receiver, which offers more surface area and high-temperature distributions, representing more heat absorption and utilization to convert into thermal energy. The crucial design of a cascaded receiver consists of two concentric steel cylinders with different heights attached at one end. The design is tested theoretically with the help of CFD analysis, and the heat loss results are compared with the traditional cavity receiver. Furthermore, according to design, an experimental set-up is fabricated, and experimentations are conducted in off-flux mode using an electric heater. The Pyromark coatings minimize radiation losses and implement the working conditions in the lab testing scenario. The convective heat losses estimated reduction of 4.3 % at 0°–24.8 % at 90° due to the application of coatings in the normal cavity and 3.4 % at 0°–16.4 % at 90° due to the application of coatings in the cascaded cavity. Also, the cascaded cavity receiver minimizes 6.98 %–13.93 % convective heat losses compared to traditional cavity receivers.

Experimental performance and economic analysis of finned solar receiver for parabolic dish solar collector

The solar receiver is a vital component of concentrated solar collectors that absorbs solar radiation and converts it into heat. One of the challenges the research community faces is minimizing heat loss from the receiver at higher temperatures to maximize the thermal performance of parabolic dish collectors and achieve the system's cost-effectiveness. Cavity receivers have a complex design that makes them more challenging to manufacture and entails higher costs for improved thermal performance. Implementing innovative receiver designs is essential to maximize the absorption of solar radiation and minimize heat losses. In this experimental study, a cost-effective solar receiver was fabricated with fins to study heat transfer. The solar receiver is examined using water as heat transfer fluid with three flow rates of 0.097 kg/s, 0.125 kg/s, and 0.152 kg/s. The residence time of water is increased by adopting integrated fin receiver designs. The provision of fins in the solar receiver enhances heat transfer by increasing the turbulence in the fluid flow and results in higher thermal efficiency. The average energy and exergy efficiencies are 67.81 % and 8.93 %, respectively, with a 0.152 kg/s flow rate. At the highest water flow rate (0.152 kg/s) considered in this study, a lesser heat loss of about 3776.2 W occurred due to the effective heat transfer. The cost metrics, like levelized cost of electricity, net present value, and the payback period, are about 0.21 $/kWh, 923 $, and 3.38 years, respectively, at 0.152 kg/s flow rate. The proposed solar receiver produces optimal thermo-economic performance and lower initial investment for steam generation than other receiver designs. The current experimental study's findings could benefit the entire solar industry by presenting an effective solar receiver design for solar collectors.

Integrated optical and thermal model to investigate the performance of a solar parabolic dish collector coupled with a cavity receiver

The cavity receiver is the most promising type of receiver, which drops the heat loss and converts the incoming concentrated radiation to useful energy. In this work, the coupled optical-thermal investigation is performed for a novel cavity receiver of a 40 m2 parabolic dish collector to estimate the thermal performance. The variation of thermal performance with inclination γ, wind direction ψ, wind speed V, and inlet temperature THTF,i has been discussed. SolTrace and ANSYS® Fluent are used for optical and thermal modeling, respectively. Surface errors, heat flux at each coordinate of the receiver, and the parabolic dish effect have been considered in the study. The text user interface (TUI) over graphical has been adopted in ANSYS® to reduce the computational expenditure for variation of parameters. In thermal modeling, a user-defined function (UDF) is applied for mapping data from SolTrace simulation with 107 rays. Therminol 66, as heat transfer fluid, is used in the receiver coils. The optical performance of 84.15% is achieved at an aiming height of 4.5 m. The thermal performance of 73.11% is obtained as maximum in no-wind conditions for 90° tilt. The worst thermal performance is obtained in side-on wind. Further, the performance has been compared with other models and found to be performing well.

Optical and thermal analysis of solar parabolic dish cavity receiver system for hydrogen production using deep learning

The solar thermochemical cycle, responsible for converting solar energy to chemical fuel, is an emerging clean hydrogen production technique. The distribution of the concentrated heat flux and temperature on the receiver is crucial in deciding solar-to-fuel conversion efficiency. Thus, the optimum configuration of a solar parabolic dish collector (PDC) is necessary for providing efficient thermal energy. The dish diameter, rim angle, and distance of the receiver aperture from the focal point of the dish characterize the optimization of the PDC. The non-uniform heat flux captured is coupled with a heat transfer model of a solar thermochemical reactor for a thermal dissociation of ZnO involved in a ZnO/Zn thermochemical cycle for hydrogen production. The directly irradiated rotating reactor comprises a cylindrical cavity packed with insulation layers and a quartz glass window. The rotating cavity is loaded with ZnO granular particles held by a centrifugal force. A 3D CFD numerical model is analyzed by coupling the Eulerian multiphase model for ZnO particle dynamics, fluid flow of gaseous mixture, RNG k-ԑ turbulence model, Energy and Discrete Ordinates (DO) radiation model, and Arrhenius reaction rate chemical reaction of ZnO dissociation. A numerical model with non-uniform heat flux input is validated for a cavity temperature, mass fraction of zinc and oxygen, and oxygen molar flow rate at the reactor outlet. An artificial neural network model is adopted to predict the heat flux and uniformity factor values of PDC. Correlation Coefficient (R2), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE) error metrices were used to evaluate the model's performance having the receiver diameter (d), the dish diameter (D), the rim angle (φ), and the distance between the focus and receiver (h) as input variables.

Experimental performance evaluation of a solar parabolic dish collector using spiral flow path receiver

The solar receiver design plays a crucial role in the performance and efficiency of a parabolic dish solar collector. This experimental study examines a finned spiral flow path receiver in a 16 m2 parabolic dish collector to enhance heat transfer from the receiver surface to the heat transfer fluid. The solar receiver is evaluated outdoors at water flow rates of 0.04 kg/s, 0.05 kg/s, 0.06 kg/s, and 0.12 kg/s. At water flow rates of 0.04 kg/s, 0.05 kg/s, and 0.06 kg/s, the receiver's average energy efficiency was 31.27 %, 44.34 %, and 50.69 %, respectively. At water flow rates of 0.12 kg/s, the peak energy and exergy efficiency are around 65.81 % and 6.85 %, respectively. The proposed solar receiver shows an increased heat transfer coefficient from the receiver surface to the fluid with more fluid residence time due to the spiral flow path and fins. The economic evaluation demonstrates that the solar receiver with a flow rate of 0.12 kg/s produces the most significant economic outcomes compared to other selected water flow rates. The proposed solar receiver's estimated levelized cost of energy, net present value, benefit-to-cost ratio, and payback period values are 0.18 ($/kWh), 925.61 $, 8.40 and 1.62 years. Thus, the finned spiral flow path receiver with a flow rate of 0.12 kg/s produces optimal performance among the selected water flow rates. The significant results benefit the solar community in designing an effective finned solar receiver for concentrated solar collectors.

Numerical Study of the Parabolic Dish Solar Collector Performance Evaluation Using Heat Exchanger Receiver

Numerical Study of the Parabolic Dish Solar Collector Performance Evaluation Using Heat Exchanger Receiver

Experimental and numerical performance assessment of a hybrid parabolic dish collector with photovoltaic for a distiller

ABSTRACT Environmental pollution has been rising recently, and so clean water needing has also increased. People could have easy access to pure water in all environments and conditions. This study is the solar tracking parabolic dish collector with produced pure water independent of electricity (off-grid). This system is fully renewable and autonomous. This system possesses a receiver, a boiler, a condenser, six 1000 mm diameter parabolic dish collectors, and 1 kW photovoltaic (PV) collectors. Thermal oil uses as the working fluid in the experiments. The experiment measured solar radiation, air temperature, air velocity, oil inlet and outlet temperatures, oil flow rate, receiver side surface temperatures, and instantaneous amount of pure water. Numerical and thermal analysis of the receiver in the experimental setup carry out. ANSYS Fluent 18.1 uses for numerical analysis. Energy and exergy analysis calculates the receiver for pure water production rate. The time interval when the system operates at high performance determines. In this study investigates the behavior of some exergetic indicators on the performance of the experimental setup, the cost of the experimental setup, and the enviro-economic impact of the parabolic dish-type collector. For this purpose, some exergetic factors such as the exergy effect, environmental impact factor, waste exergy rate, improvement potential, and exergetic sustainability index examine. The receiver’s improvement potential is between 1700 and 3000 W. In addition, the sustainability index, waste exergy rate, and environmental impact factor range from 0.32 to 0.36, 0.90 to 0.94, and 2.6 to 3.0, respectively.

Topology Optimization Method of a Cavity Receiver and Built-In Net-Based Flow Channels for a Solar Parabolic Dish Collector.

The design of a thermal cavity receiver and the arrangement of the fluid flow layout within it are critical in the construction of solar parabolic dish collectors, involving the prediction of the thermal-fluid physical field of the receiver and optimization design. However, the thermal-fluid analysis coupled with a heat loss model of the receiver is a non-linear and computationally intensive solving process that incurs high computational costs in the optimization procedure. To address this, we implement a net-based thermal-fluid model that incorporates heat loss analysis to describe the receiver's flow and heat transfer processes, reducing computational costs. The physical field results of the net-based thermal-fluid model are compared with those of the numerical simulation, enabling us to verify the accuracy of the established thermal-fluid model. Additionally, based on the developed thermal-fluid model, a topology optimization method that employs a genetic algorithm (GA) is developed to design the cavity receiver and its built-in net-based flow channels. Using the established optimization method, single-objective and multi-objective optimization experiments are conducted under inhomogeneous heat flux conditions, with objectives including maximizing temperature uniformity and thermal efficiency, as well as minimizing the pressure drop. The results reveal varying topological characteristics for different optimization objectives. In comparison with the reference design (spiral channel) under the same conditions, the multi-objective optimization results exhibit superior comprehensive performance.

DETERMINATION OF THERMAL EFFICIENCY AND COOKING POWER OF PARABOLIC SOLAR CONCENTRATING SYSTEM WITH THERMAL COMPENSATOR FOR DOMESTIC APPLICATIONS

Energy and the environment have a strong relationship. The production and consumption of energy is one of the biggest causes of environmental damage on earth. Therefore, the rapid increase in the level of CO2 and other greenhouse gases are given out during burning fossil fuel rise or unsteady of fuel prices are the main purposes led to a search to more effectively utilize a different sources of renewable energy. To reduce the consequences of greenhouse gases emitted by burning fuel for energy, which course depletion of the ozone layer and global warming. Therefore, the use of solar radiation directly as a source of energy has proved in the past to be less economical and affordable. The paper was aimed at determination of the performance of a parabolic solar concentrating system with a thermal compensator for domestic applications using thermal efficiency and cooking power. The parabolic dish solar collector (PDSC) with a focal point of 6.15 m, aperture area of 5.8 m2 and rim angle (φo) of 45O was designed and constructed for the determination of the variables. The PDSC was made of stainless steel reflector sheet in such a way that both the manufacturing and assembly method do not require complicated skilled techniques and cost. Since the PDSC is for high temperature steam generation, hot water and cooking application. A finite element stress test analysis was conducted to determine the thermal efficiency and cooking power of the system under various weather conditions. A simple manual solar tracking mechanism was employed, and the results of the system performance were also reported. The efficiency according to thefinding depends on the optical properties of the materials involved, the geometry of the collector, and the various imperfections arising from the construction of the collector. The thermal efficiency and cooking power of the system were determined and obtained to be 54.4% and 543.1W respectively.

Parabolic Dish Collector as a New Approach for Biochar Production: An Evaluation Study

The main factors influencing biochar properties are feedstock biomass and pyrolysis operational conditions. A solar parabolic dish collector was proposed as a new green approach to the pyrolysis process. The technique of this reactor was designed to produce biochar from sesame feedstock (SF) by concentrating solar radiation. This research aims to compare the main physical and chemical properties of biochar produced by the solar reactor to those of the conventional reactor (muffle furnace, SB-3). Biochar produced by the parabolic dish collector was a heterogeneous brown color. Depending on color intensity, biochar was divided into the biochar formed around the inner sidewalls of the internal chamber (SB-1) and the biochar formed in the upper part of the internal chamber (SB-2). Generally, the physiochemical properties of the SB-2 biochar were similar to the SB-3 biochar, while SB-1 biochar was similar to SF. This was because the temperature distribution was not uniform in the solar reactor. The proposed solar parabolic dish collector needs some modifications to upgrade the biochar production to be close to that produced by the electric instrument. SB-2 is preferred as a soil amendment depending on its pH, cation exchange capacity (CEC), elemental composition, ion molar ratio (H/C, O/C, and (O+N)/C), and acidic functional groups.

Prediction of focal image for solar parabolic dish concentrator with square facets-an analytical model.

Solar parabolic dish concentrator is one of the high-temperature applications of more than 400°C for thermal and electrical power generation. In the solar parabolic dish concentrator, the arrangement of reflectors over the surface area is the significant factor for effective concentration of solar radiation. Also, focal image is one of the most influencing parameters in the design of receiver. Among the various reflectors, the square-shaped reflectors (facets) are comparatively effective in converging the incoming radiations to attain better focal image. In this regard, an attempt has been made to predict the focal image diameter of a solar parabolic dish concentrator with a square facet of different influencing parameters using a novel mathematical model. The influencing parameters considered for the study are aperture diameter, rim angle, and facet length of the dish concentrator. Using the model, the focal image dimension and aperture area of a solar parabolic dish concentrator with square facets can be predicted accurately for efficient design of a solar parabolic dish collector system. Finally, the model is validated with the experimentally obtained focal image diameter. The current model is in good agreement with the experimental value, with a deviation of 8.84%. Hence, the proposed model can be used for the design of parabolic dish systems.

Thermal Performance Improvement of Modified Hemispherical Cavity Receiver with Air Curtain

Heat losses from solar cavity receivers degrade the efficiency of solar parabolic dish collector system. Specifically, increased convection losses emulate a significant contribution in decreasing the performance of the modified solar cavity receiver and hence, reducing these convection losses has become a matter of great concern. The Air curtain plays a crucial role in minimizing the convection losses. This work proposes an air curtain-based modified cavity receiver wherein a plane nozzle is placed on the face of receiver to produce air curtain effect. Air curtain will prevent hot air from escaping the modified cavity receiver and increase the stagnation zone inside it to reduce natural convection on the surfaces. Numerical analyses are performed considering different air velocities and receiver orientations to evaluate the effect of air curtains on the convection losses. The impact of plane air nozzle parameters like outlet temperature, inclination, and outlet velocity of the nozzle on convection losses are shown and these parameters’ optimal value is evaluated. Our results state that the air curtain attached to the modified solar cavity receiver significantly improves performance by reducing the convection losses.

Techno-economic evaluation of solar-driven ceria thermochemical water-splitting for hydrogen production in a fluidized bed reactor

Thermochemical water splitting (TCWS) is an attractive and promising approach for hydrogen fuel production to replace fossil fuels and address climate change. The novel approach used in this study is the indirect irradiation of the ceria particle with solar-heated nitrogen in a fluidized bed reactor which improved the ceria thermo-reduction and increased hydrogen yield. The TCWS plant featured additional units for oxygen co-production, and excess heat recovery to generate electricity and reduce the saleable hydrogen price. Two fluidized bed reactors for ceria thermo-reduction and oxidation using steam were modelled in Aspen Plus for hydrogen production at a 70% capacity factor. A photovoltaic (PV)-battery module in addition to the solar parabolic dish collector (PDC) was then used to deliver operation-round electricity supply and drive mechanical and control systems, reducing overall plant energy cost. Three minimum selling prices of hydrogen were considered based on the achievable products of the TCWS plant: (i) pricing based on no co-products, (ii) pricing including oxygen revenue, and (iii) pricing including oxygen and electricity revenue. The TCWS plant achieved a minimum selling price (MSP) of 3.92 USD/kg H2 (including oxygen and electricity revenue) at a 10% discount rate which is the lowest for solar-driven TCWS hydrogen compared with other similar studies. Sensitivity analyses showed that discount rate, steam Rankine cycle, power block, cost of ceria and hydrogen storage, and price of oxygen, respectively, had the highest impact on the MSP of the TCWS hydrogen plant. The switch value analysis (SVA) was used to determine the potential of achieving the global target hydrogen price of 2 USD/kg based on a single parameter assessment. The TCWS plant proposed in this work provides a promising approach toward achieving future hydrogen prices below 2 USD/kg when a lower discount rate of 5% is utilised. It was established that the choice and size of concentrated solar power (CSP) technology integration, co-generation, and heat recovery are critical to the system efficiency and economic viability of a solar-driven TCWS hydrogen production. This work demonstrated the use of ceria as a metal oxide feed suitable for solar TCWS hydrogen production with a promising economic potential for a global target price of less than 2 USD/kg H2 based on the choice of process-CSP configuration.

Thermal Energy Application and Evaluation of Parabolic Dish Solar Collector

Thermal Energy Application and Evaluation of Parabolic Dish Solar Collector

Historical overview of power generation in solar parabolic dish collector system.

Solar energy is a promising form of energy that has the potential to meet all of the world's energy needs. Only half of the sun's energy reaches the earth's surface, even though it is more enough for meeting the world's energy need. Though there is a great deal of solar energy utilization technologies available, solar parabolic dish collector system got researchers focus because of its higher thermal energy conversion efficiency and its unique advantages. Several researchers have been enlightening new and emerging technologies in several countries. Hence, the authors would like to emphasize the progress in this while exercising an extensive review of different solar concentrating techniques using solar parabolic dish collector in order to produce heat and electrical power using direct and indirect energy conversion devices with wide range of applications. Their design advancement and progress applications in recent years particularly in related field are discussed too.

Convective heat loss prediction from conical cavity receiver of solar parabolic dish collector using numerical method and artificial neural network

In this work, detailed investigations of convection heat loss from conical cavity receiver of solar parabolic dish collector using a numerical method and artificial neural network have been performed. The convective heat loss from the cavity receiver is primarily influenced by geometrical parameters, receiver orientation, and wind characteristics. The heat loss estimation is carried out by considering wind speed (V = 0–10 m/s), wind direction ( = 90 and −90), receiver tilt ( = 0–90), diameter to height ratio (d/h = 0.5–1.5), and surface temperature (T s = 500–800 K). The utmost heat loss occurs at a tilt of 60 for d/h < 1 and 75 for d/h 1 in head-on high wind speed, while in back-on high wind speed, it occurs at a tilt of 30 for all d/h values. The heat loss is lowest at 90° for V > 4 m/s. The d/h value of 0.5 performs well compared to other values. Further, the correlation for the Nusselt number has been proposed for the conical cavity receiver.

PERFORMANCE EVALUATION OF PARABOLIC CONCENTRATOR WITH THERMAL STORAGE SYSTEM FOR DOMESTIC APPLICATIONS

Solar energy is a free natural resource but its harvesting requires a high capital investment whichprohibits its maximum exploitation. A Parabolic Dish Solar Collector (PDSC) with a thermalstorage system was been constructed and developed to harness solar beam radiation. The thermalstorage system and PDSC were constructed using locally and less cost materials such asgalvanized metal sheet and steel rods curved to obey the equation of a parabola then weldedtogether with circular support rings which was then lined with stainless steel reflector pasted forthe construction of PDSC. The receiver was made of blackened aluminium material incorporatedwith coiled copper tube carrying water as the heat transfer fluid. A parabolic dish which acts of aheat collector is used to track and reflects solar radiation at a single point (focus) on a receiverabsorber. Heat transfer from the solar collector to the storage tank was done by usingthermosyphonic principle to circulate the water (heat transfer fluid) between storage tank andheating system (receiver). The evaluation of thermal storage and analyzing the efficiency oftracking and non-tracking parabolic dish solar collector was carried out during month of June,2020 for the composite climate of Sokoto. According to the finding, the efficiency of trackingPDSC with thermal storage system and non- tracking PDSC with thermal storage tank weredetermined and obtained to be 52.9% and 50% respectively.Keywords: thermal efficiency, parabolic dish collector, solar radiation, storage system andstainless steel reflector.