Parabolic Collector Research Articles

Ray Tracing and Simulation of Parabolic Dish Collectorusing Soltrace for Vehicle Applications

Concentrated solar power has the potential to produce large-scale renewable energy sources. Concentrated solar energy is produced using mirrors, reflective materials, or lenses on conical surfaces such as a parabolic dishes, parabolic troughs, towers, Fresnel reflector systems, and dish sterling collectors. The concentrated light source was converted into heat energy, which drove the heat engine into an electrical power generator. To gain more heat energy, the solar rays must be trapped and concentrated on their conical focus points. To increase the net overall efficiency of the system, it is vital to know the optical performances of the subsystem formed by the solar receiver and the parabolic concentrator. In this study, a beam of incident solar rays was traced on a parabolic dish collector, and a simulation is performed for concentrator behaviour using the ray-tracing code SolTrace developed by the NREL laboratory. For an incident radiation of 1000 W/m2 (considering 10000 photon rays), their optical performance and solar heat flux were simulated. The results show that the number of elements in SolTrace varies depending on the CFD mesh density, the number of rays utilised in the Monte Carlo technique and their impact on generating a resolution-independent solution. Investigating the ray tracing of the disc concentrator, the propulsive energy for viable applications can be analysed.

EXPERIMENTAL ANALYSIS OF HEAT TRANSFER AND THERMAL PERFORMANCE OF PARABOLIC TYPE SOLAR COLLECTOR WITH RIBBED SURFACE TEXTURE FOR CLEAN ENERGY EXTRACTION

This paper examines the performance of a parabolic type solar collector (PTSC) that uses both plain tube and ribbed surface textured tube channels for elevating the water temperature used for various applications. The performance of a solar water heater is evaluated experimentally. During the experiment, the solar radiation intensity and the feed water flow rate of 1.0 kg/min to 5.0 kg/min in steps of 1 kg/min are taken into consideration for analyzing the effect of ribbed textured tubes on the thermal effectiveness, frictional factor, convective transfer of heat, Reynolds number, and the Nusselt number of the PTSC. Furthermore, the overall performance of the PTSC is analyzed considering the above thermo-physical parameters. Based on the result of this study, at a flow rate of 3.0 kg/min, the thermal efficiency is found to be enhanced by about 28.25%, the friction factor is augmented by about 0.23%, the convective heat transfer coefficient is improved by 24.22%, and the Nusselt number is increased by about 26.32%. On average, an overall improvement in the performance of 8.25% is observed for the ribbed textured tube than that of the plain tube. The experimental error analysis shows that the standard deviation for both plain and ribbed textured tubes is in the range of 3.2, which is in the acceptable limit.

Efficiency of a Compound Parabolic Collector for Domestic Hot Water Production using the F - Chart Method

Efficiency of a Compound Parabolic Collector for Domestic Hot Water Production using the F - Chart Method

Efficient model for solar steam generation

In this research, an advanced hybrid steam generation system using solar energy was designed, with higher performance and lower cost compared to other systems and researches. It's an ideal system where fossil fuels are still plentiful. The selected system units with the innovative automatic control allows the absorption of all levels of solar radiation and its exploitation in steam generation. The boiler is a classic fire tube one and the solar collector is a modified linear parabolic collector that tracks the sun in one of three tracking modes. A proper Matlab program has been prepared to determine and demonstrate the performance of the system and the optimal characteristic values of the collector that provide the maximum seasonal solar fraction of the plant. It was found that the average monthly daily solar fraction of the plant in Antalya, Mediterranean region, is 0.85 in June and 0.28 in January with the collector optimal characteristics and east-west tracking within 12 hours stable daily steam generation. It is demonstrated that the deviation in an optimum characteristic value of the collector causes a reduction in solar fraction. This study forms the basis for a similar plant construction project to test it in practice under real climatic conditions.

Optical and hydrodynamic performance of photocatalytic monoliths of different shapes in a solar photoreactor with compound parabolic collector

Radiative transfer and hydrodynamic analyses are carried out to study the performance of solid macroscopic pieces (monoliths) of TiO2 photocatalyst in a CPC solar reactor. The absorbed photonic flux distribution was solved through Monte Carlo simulations for different monolith geometries: asterisk and flower shapes. In the case of the asterisk geometry, different numbers of arms (lobes) are considered. The performance of the monoliths in a tubular Pyrex photoreactor is numerically studied under both diffuse and collimated UV solar irradiation on the CPC. Also, the case of a homogeneous diffuse illumination on the glass tube, without CPC reflection, is considered. Hydrodynamic simulations are also carried out to determine the overall friction factors in the presence of the different pieces. Significant differences are observed for the results between different monoliths. Absorbed power varies up to 36%. On the other hand, the peak flux is the same for all pieces, but the standard deviation of its distribution may be up to 65%. The effect of partial specularity in the reflection by the TiO2 surface is also studied, resulting in a maximum deviation of just 4.2% in the flux values between 25% and 75% specularity. Two different positions for a monolith inside the glass tube were considered, with some significant differences in the flux distribution, but with changes below 4% in total absorbed power. With regards to the hydrodynamics, laminar flow of water along the pieces inside the tube was considered. Differences higher than one order of magnitude are observed in the friction factor for different pieces, being the void fraction inside the tube the main parameter affecting this change. The results of this work are relevant to understanding the potential effect of using catalyst pieces with different geometry on a photocatalytic reactors performance; inadequate geometrical design of this component may lead to diminished light collection or substantially increased pressure drops for scaled up systems.

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.

Solar-assisted oxidation of organochlorine pesticides in groundwater using persulfate and ferrioxalate

The oxidation of hexachlorocyclohexane isomers in the aqueous phase (Milli-Q and groundwater) was studied using persulfate activated by ferrioxalate and solar light at circumneutral pH. The experiments were conducted in a solar simulator reactor with local radiation fluxes qw= 1.12·10−7 E cm−2s−1 and in compound parabolic collectors with solar light (qw≈10−7 E cm−2s−1) for 390 min. The effect of activator dosage (18–125 μM ferrioxalate) and persulfate concentration (520–2600 μM) on hexachlorocyclohexane conversion and oxalate and oxidant consumption was analyzed. Conversion of about 95% of β isomer was achieved at 390 min using 1300 μM of initial persulfate and 63 μM of Fe3+ concentration despite this β isomer being the most recalcitrant to oxidation (XHexachlorocyclohexanes=0.98). Dechlorination above 80% was achieved under these conditions, analyzing the chlorides released into the water.The influence of chloride and bicarbonate on hexachlorocyclohexanes degradation was analyzed in milli-Q water and in groundwater. Hexachlorocyclohexane conversion at 390 min decreases from 98% to 83, 75 and 65% in the presence of chloride, bicarbonate or groundwater, respectively. Results obtained with compound parabolic collectors and solar light using 2600 μM Na2S2O8 and 63 μM Fe for removing hexachlorocyclohexanes agreed with those from the solar simulator reactor, supporting using solar light to activate persulfate for sustainable abatement of persistent organic pollutants in aqueous matrixes.

Performance of compound parabolic concentrator solar air flat plate collector using phase change material

This work involves an experimental investigation on two different new models of Compound Parabolic Concentrator (CPC) solar air flat plate collector with adding paraffin wax Phase Change Material (PCM). The first model is called involute shape model, whereas the second model is called normal shape model. To explore the best model performance, the structures of compound parabolic concentrator models have two symmetric giant parabolic mirror reflectors, similar concentration ratio of 1.7, similar flat plate receiver with 12 tubes filled by paraffin wax phase change material. The performances of both models are presented together for purpose of comparison. The tests have been performed in April and May 2023 in Mosul city/Iraq under standard conditions for around 11 h during the day. The outcomes indicated that rising in air mass flowrate leads to rise the receiver performance. The findings confirm that the thermal efficiency of normal shape is more efficient than involute shape by 7.6%, 13%, and 11.7% for 0.0085 kg/s, 0.0174 kg/s, and 0.027 kg/s, respectively. The optimum thermal performances for involute and normal shapes have been obtained equal 65.4% and 77.1% for 0.027 kg/s, respectively. For constant air flowrate, the performance of normal shape is higher than involute shape by 15.5% (14th May), 12.6% (27th April) and 11.8% (15th April). A significant temperature change has been found in involute shape as compared to normal shape. The outlet temperature of normal shape is always lower than the involute shape for all air mass flowrate. It is demonstrated that phase change material and the position of the receiver have considerable influence on the model performance. The current work provides an important information for evaluating the compound parabolic concentrator model performance for Mosul/city.

A parabolic solar collector for harnessing solar energy in Bucaramanga, Colombia

In this work, a solar energy collection system based on a parabolic solar collector adjusted to the conditions and availability of energy was designed to examine this type of collection device and evaluate the energy potential when installed in an educational institution. To do this, data from the historical series of solar radiation compiled by the POWER project (Prediction of Worldwide Energy Resources) were analyzed and compared with data from the Institute of Hydrology, Meteorology and Environmental Studies in Colombia (IDEAM).

Thermal analysis of operating a solar-powered diffusion absorption refrigerator with a parabolic collector

This study investigates the use of solar energy, one of the leading renewable energy sources, to power a diffusion absorption refrigerator, thereby demonstrating the feasibility and practicality of renewable energy applications without relying on electrical energy or fossil fuels. Two mini refrigerators with identical power and features were employed in the experimental study. The aim is to evaluate the performance of two refrigerators, one powered by electricity and the other by heat from a parabolic solar collector. The heat transfer oil circulating in the parabolic solar collector was transferred to the generator of the solar refrigerator through a special apparatus. Various parameters such as mass flow rates, system pressure, solution concentrations, and thermal and COP values of diffusion refrigerators were meticulously analyzed. Experimental results obtained from both refrigerators were compared for a comprehensive evaluation. While the Coefficient of Performance (COP) of the electric refrigerator was determined as 0.398, the COP value of the solar refrigerator was determined as 0.380. These findings highlight the potential of solar energy in sustainable cooling applications and provide valuable information on comparing electric and solar cooling systems. The study contributes to the ongoing efforts to promote eco-friendly and energy-efficient technologies, emphasizing the role of solar energy in reducing dependence on traditional energy sources.

Building heating by solar parabolic through collector with metallic fined PCM for net zero energy/emission buildings

Net Zero Energy/Emission Buildings is one of the most popular study goals to make systems that are very good for society. In parabolic through collector (PTC) devices, the absorber is a key part of the solar collector that takes in the concentrated sun rays from the mirrors. PTC systems are used to make steam, which is used to heat homes, run restaurants, and do work in factories, among other things. In this work, the PTC absorber was used as a test subject. Phase Change Material (PCM) was used to store heat energy so that it could be used later to heat buildings. This study concentrates on developing a more efficient and effective PTC absorber configuration that can play a pivotal role in achieving Net Zero Energy/Emission Buildings by optimizing the use of solar energy for heating purposes while minimizing energy waste and environmental impact. Hence this investigation aims to maximize the energy efficiency and minimize the exergy efficiency by optimizing the number of Fins and their positions in the PCM-embedded PTC for building heating. In this regard, this investigation considered a different number of fins (2, 4, 8, and 12) and they were placed at angles of 180°, 90°, 45°, and 30° to recover the heat back from the PCM to heat transfer fluid in the absorber. With 8 fins on the absorber, the highest average exit temperature of the heat transfer fluid (HTF) is about 94°. The PTC system's highest average energy and exergy were found to be about 72.3 % and 7.05 %, respectively, at the absorber with 12 fins. The PCM moves heat into the air for building heating uses. This keeps the building warm during the winter. Because of this, the absorber with 12 fins works better than absorbers with less fins. This type of absorber, which is made up of 12 fins, does a good job of meeting the standards of Net Zero Energy/Emission Buildings for heating buildings. When the black material was put on the top of the absorber, it cut down on the amount of heat that was lost to the surroundings.

Machine learning models for predicting the performance of solar-geothermal desalination in different meteorological conditions

This research aimed to evaluate the amount of produced fresh water (FWP) in a desalination system based on humidification-dehumidification using TRNSYS software. The study was conducted for one year, analyzing the results for five cities in Iran with different climatic conditions. Meteorological data from Meteonorm software were used for the simulation. Different heating sources, including solar energy (SE) and geothermal energy (GE), were considered in the design. The impact of using three types of collectors and the simultaneous use of SE and GE heating sources was investigated. The findings showed that using a flat plate solar collector resulted in the highest FWP in June and July, as well as during certain day time hours with increased solar radiation intensity. Increasing the number of flat plate collectors and their cross-sectional area intensified the FWP about 10.60%–33.16%. When SE and GE were used as heat sources, increasing the mass flow rate of water and air entering the system led to a decrease and increase in FWP, respectively. The highest FWP for Hamedan city was achieved when using GE simultaneously with a compound parabolic collector. Exergy destruction was analyzed for humidification and dehumidification devices, with the maximum observed in the case of Type74. The LSTM deep learning neural network and the Gaussian process (GP) machine learning algorithm were used to approximate the desalination efficiency, with the GP method exhibiting slightly higher accuracy.

Comparative assessment of direct absorption solar collector performance in different climates

Energy supply and environmental protection by reducing pollutants are among the main challenges these days. As a clean and sustainable source, solar energy is capable of generating thermal and electrical power. In this regard, Iraq is one of the regions with high solar energy harvesting potential. A numerical model was developed and validated by experimental findings in MATLAB software. This model, which also included geometrical and optical characteristics, was developed using information from four cities representative of different climates in Iraq: Baghdad, Samawa, Mosul, and Al-Qa'im. This study examined the effects of climate on the performance of direct absorption parabolic solar collectors used for energy production in Iraq. According to the results, solar collectors in Samaveh provide the highest thermal energy efficiency (up to 66.5%). Even thoth, the highest exergy efficiency is found in Al-Qa'im (36.21%). From an environmental point of view, the collector in Al-Qa'im has the highest CO2 mitigation (2.73 kg per m2 of collector) every year. As compared to other cities, Al-Qa'im and Samawah have a high thermal efficiency and solar intensity, which can lead to more water and energy savings.

NUMERICAL ANALYSIS OF COMPOUND PARABOLIC SOLAR COLLECTOR WITH TWO GLASS COVERS

In a compound parabolic solar collector, a glass cover is normally used for decreasing the rate of heat loss from the absorber. In this paper, a solar collector with two glass covers and a concentration ratio of 1.6 is simulated and examined for the purpose of higher performance. The distance between covers is 45 mm and the cavity of solar collector is filled with air. Due to the temperature gradient, the turbulent free convection airflow takes place inside the cavity. As the main aim, the effect of the second glass sheet on performance improvement is examined. Towards this end, the equations govern to the turbulent buoyant airflow in the collector’s cavity was numerically solved by the finite element method using the COMSOL Multiphysics software. Also the conduction equation is employed for temperature computation in the solid elements. Numerical findings demonstrate the effective role of the second glass sheet in decreasing the rate of heat loss from solar collectors and a more than 6% increase in the thermal efficiency of the studied test cases is found because of the second glass sheet. Comparison between the numerical findings of free convection airflow with experimental data shows good consistency.

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.

Solar-driven chemisorption cogeneration system integrated with thermal energy storage

In this study, a power and cooling cogeneration system is introduced, consisting of a chemisorption cycle, a latent heat thermal energy storage (TES) system employing phase change materials (PCM), and a solar system employing compound parabolic collectors (CPC). The system is targeted at being employed in a residential area in Shiraz City and TRNSYS and MATLAB software environments are utilized to simulate and assess the system. In the system, power is generated by a turbine with the pressure difference elicited through the chemical reaction in the chemisorption cycle. Also, the cooling is produced via the evaporation of ammonia in the evaporator. The effect of the supplied hot source temperature for the reaction in the adsorbent bed was investigated. It was observed that in the 100–200 °C heat source temperature range, the total energy efficiency increased from 0.313 to 0.467 and the COP for the refrigeration process reduced from 0.71 to 0.53. Also, the maximum overall energy and exergy efficiency in this temperature range were 0.46 and 0.405, respectively. Also, at the heat source temperature of 200 °C, the average maximum electrical power and cooling capacity were gauged at 2.7 kW and 14.5 kW, respectively. In the TES system with a volume of 1.5 m3, the maximum achievable capacity was 250 kWh and the solar system showed its highest temperature in July and August. It was observed that heat source temperature augments the production capacity of the system while it reduced the coefficient of performance (COP) of the system. Sustainable development goals (SDG) impact [Display omitted]

Experimental investigation of a novel design of cavity receiver for a parabolic dish collector humidification-dehumidification desalination system

In this study, a desalination cycle using a humidification-dehumidification method equipped with a parabolic dish collector has been experimentally designed and tested under the climatic conditions of Semnan City. A novel geometry of cylindrical-conical for parabolic dish collector’s cavity receiver was selected and used in this desalination system. For the experimental tests, four water samples were selected from the non-conventional brackish water sources in Semnan province. The performance of the desalination cycle was investigated for four days in the maximum period from 9:00 a.m. to 3:00 p.m. According to the results obtained from the tests, the maximum thermal efficiency of the collector with the cylindrical-conical cavity receiver for the test with water sample with electrical conductivity of 21,500 µS/cm was obtained as 45.49%. The highest water production rate was 0.966 l/day for a water sample with an electrical conductivity of 13,810 µS/cm. The average hourly water production rate for the saltiest water has reached the highest value, equivalent to 147.67 cm3/h. It was also found that there is an increasing trend of water production with an increase in the salinity of brackish water. The maximum hourly exergy efficiency of the system was 14.04% for a water sample with an electrical conductivity of 21,500 µS/cm. An increase in hourly exergy efficiency was observed with the increase in water salinity.

Investigating the thermo-economic performance and modeling of a parabolic solar collector with phase change material in the receiver tube in a solar desalination

Solar desalination is a suitable and cost-effective system for producing drinkable water from salt water. The main goal of this study is improving the thermal performance of the solar desalination with latent thermal storage system and the panel detector. The heat loss from the solar collector increases due to the fluctuations in the intensity of solar radiation and the use of phase change materials is a suitable solution for storing energy during peak hours and releasing it when the solar radiation intensity is reduced or absent. Thus phase change material (paraffin) placed in the focal tube in the form of a 6 mm spiral pipe with a pitch of 7 cm. Thermal performance of the collector was carried out at three fluid flow rates of the working fluid at 1.9, 1.3 and 4.2 l/min with phase change material and without phase change material in four consecutive days from 10:00 to 14:00. The results of the showed that the solar water desalination equipped with phase change materials had the highest thermal efficiency at the fluid flow rate of 4.2l/min and the lowest with a flow rate of 1.9 l/min. The results showed that the using phase change material improves the thermal efficiency by 3.05 %. Produced fresh water during 4 h was 0.722l/m2 and it significantly reduced the hardness of drinking water. The solar collector simulated by Anysy and the simulated results showed a good correlation between the predicted and experimental data with reasonable accuracy (R2 > 0.97).

Enhancement of Condenser Performance in Vapor Absorption Refrigeration Systems Operating in Arid Climatic Zones—Selection of Best Option

Generators and condensers are the two vital equipment items that determine the output of vapor absorption refrigeration systems. Arid weather conditions produce a significant reduction in the performance of the vapor absorption refrigeration cycle due to low condenser heat dissipation despite high generator temperatures. Although numerous studies on condenser cooling methods in vapor compression systems have been reported in the literature, solar-operated vapor absorption systems have not been studied. Limitations in generator temperatures of solar-operated vapor absorption systems necessitate a focused study in this area. This study makes the selection of the best choice for condenser cooling from among four different condenser cooling methods which have an impact on the performance of the vapor absorption refrigeration system for effective cooling using solar energy. A solar vapor absorption refrigeration system working with low-grade heat using a compound parabolic collector is considered in this study. Analysis of a vapor absorption refrigeration system for cooling in arid weather conditions is carried out using different condenser cooling methods with Engineering Equation Solver. Initially, the model used in the study is compared with a similar study reported in the literature. Techniques considered are air, water, evaporative, and hybrid cooling techniques. The performance of the vapor absorption cooling system was analyzed using experimental values of a solar compound parabolic collector obtained from real-time measurements for simulating the model. Results show that water cooling can provide suitable condenser cooling and improve the coefficient of performance of the solar vapor absorption refrigeration system using the solar collector. The water-cooled condenser has 1.9%, 3.3%, and 2.1% higher COP when compared to air-cooled condensers for spring, summer, and autumn seasons respectively, whereas the water-cooled condenser cooling recorded 6%, 14%, and 8% higher COP relative to the evaporative cooling method. Cost comparison showed maximum cost for water-cooled condensers and minimum cost for hybrid-cooled condensers. The effect of each cooling method on the environment is discussed.