Performance Of Parabolic Trough Collector Research Articles

Effect of the X-grid static mixer flow inserts on the performance of parabolic trough collector

Solar energy is a very convenient and reliable renewable energy source to fulfill our society's wide variety of energy requirements. Solar concentrator-based energy technologies are the best way to utilize solar energy nowadays. Among those technologies, PTC (Parabolic Trough Collector) is a well-mature and reliable concentrating solar power technology having various real-world applications with solar standalone as well as in hybrid modes. For improving the performance of PTC, flow inserts are a very promising technique. This work aims to investigate the X-grid static mixer flow inserts on the performance of the PTC module. Here, X-grid static mixer flow inserts are modeled and compared with the simple cylindrical tube without any inserts inside by using a validated model in Ansys Fluent 18.1. Evaluation criteria include flow analysis, overall efficiency, exergy efficiency and thermal efficiency. The overall efficiency and exergy efficiency are the most prominent factors for the evaluation of PTC performance. The PTC is analyzed with various inlet fluid temperatures ranging from 303 K to 653 K with a variation in the volumetric flow rate ranging from 50 LPM (Litre Per Minute) to 250 LPM. The enhancement in the thermal performance of PTC using an X-grid static mixer is more as the inlet fluid temperature increases. The pressure drop increases multiple times with the use of X-grid flow inserts, but the overall rise of pump work is low. Overall thermal efficiency is higher for the X-grid static mixer than the plain tube which is mainly used in the PTC. The presented investigation results can be helpful for the design of X-grid static mixer.

Detailed performance analysis of parabolic trough collectors including geometric effect

Parabolic trough collectors (PTCs) have been known for years as one of the leading methods for extracting energy from the sun. In the present work, the performance of PTCs was investigated. However, its performance needs some improvement to be integrated in more and wide range of applications. This idea motivated the author to investigate the performance of parabolic trough collectors in detail. Thus, in the present work, the performance of parabolic trough collectors is investigated. The effect of eight geometric and inlet variables on the PTC performance was evaluated. Two performance factors , the temperature difference and thermal efficiency, were selected. The effect of inlet condition, including inlet mass flow rate and inlet flow temperature reflector geometry, including reflector length and width,receiver diameters, including inlet and outlet reciever diameters, and cover diameters, including the inlet and outlet cover diameters on these PFs was assessed. Eight thermal working fluids were considered. A non-linear mathematical model was developed for PTC and implemented into MATLAB code where an iterative technique was used to conduct the present analyses. Level curves were generated to study the PTC key performance parameters. The curves revealed that the maximum values of the PFs and maximum range of change in these PFs occurred when the inlet conditions were varied. Changes in the inlet temperature, and changes in the reflector geometry yielded the highest and second-highest values. The cover geometry had the minimum effect on the PFs. Moreover, the best maximum efficiency, best maximum temperature difference, and maximum range of efficiency change were obtained for water, air, and carbon dioxide, respectively. The effect of inlet temperature is more significant than the mass flow rate effect on the thermal efficiency, whereas this effect is reversed in case of the temperature difference, by which the mass flow rate exerts the least influence on the temperature difference.

Evaluating the effect of using nanofluids on the parabolic trough collector's performance

AbstractSolar collectors utilize solar energy, a sustainable and renewable source, to cater to both household and industrial needs. This paper investigated the usage of mono and binary nanoparticles in parabolic trough collectors. This paper used multiwalled carbon nanotube/Fe3O4 nanoparticles as the additives to the collector heat transfer fluid (in Syltherm 800 oil) and also evaluated the performance implications of energy systems in six scenarios. A MATLAB‐based computational model is provided to investigate the influence of employing binary nanoparticles on a solar collector's performance. The influence of nanoparticle modifications and volume percentages on energy, exergy, economic, and environmental aspects is studied. Finally, the impact of nanoparticles on each of the four mentioned areas is examined. At the same total energy rate, in the best case, adding 4% by volume of Fe3O4 (Case 2) to the base fluid increases the valuable energy rate absorbed from 7.32 kW in the base state to 7.50 kW (2.5%). The carbon dioxide produced in the system life cycle by using useful energy is called EnergoEnvironmental, and the carbon dioxide produced in the system life cycle by using useful exergy is called ExergoEnvironmental. At last, the calculation of the parameters EnergoEnviroEconomic and ExergoEnviroEconomic are done, the penalty policy is considered, and the calculations are generalized to solar collector power plants due to the carbon dioxide cost policies.

An experimental investigation of nanofluid, nanocoating, and energy storage materials on the performance of parabolic trough collector

Currently, parabolic trough collectors have been widely employed for medium-high heat generation applications such as heat generation processes and desalination applications. Hence, this study tries to enhance the thermal performance of the traditional parabolic trough collector by several methods, including the use of Nanotechnology and thermal energy storage materials. An experimental setup was carried out in Kafrelshiekh city, Egypt to investigate the influence of the enhancing methods used on the thermal performance of PTC. Due to its high accuracy and the fact that many recent articles used numerical techniques without validating their findings, the experimental method is used. The study's enhancing techniques involve the use of many passes of the absorber tube, the use of TiO2 nanofluid as the heat transfer fluid, coating the absorber tube, and without employing a vacuum, reducing thermal losses caused by the presence of air by using a thermal energy storage material (graphite) in the annulus. After that, a comprehensive comparison between all cases is performed to indicate the most effective method. The performed comparative investigation showed that there is an enhancement in the thermal efficiency by 39.3%, 54.2%, 57.7%, 70.5%, and 85.4% when using the new absorber tube configuration, coating the absorber tube, using TiO2 nanofluid as the heat transfer fluid, using the previous methods together, and finally using a thermal energy storage material (graphite) in the annulus with the last modified system, respectively, as compared with that of the reference parabolic trough collector system. Hence, the proposed system was the G PTC as it offered the highest average thermal efficiency and conserved an approximately constant efficiency that was close to the maximum value during the whole day.

Performance of Parabolic Trough Collector with Different Heat Transfer Fluids and Control Operation

Electricity generation from solar energy has become very desirable because it is abundantly available and eco-friendly. Mathematical modeling of various components of a Solar Thermal Power plant (STP) is warranted to predict the optimal and efficient operation of the plant. The efficiency and reliability of STPs are maximized based on different operating strategies. Opting for proper Heat Transfer Fluid (HTF), which is proposed in this paper, helps in reducing operating complexity and lowering procurement cost. The Parabolic Trough Collector (PTC) is the heart of STP, where proper focusing of PTC towards solar radiation is the primary task to maximize the outlet temperature of HTF. This maximum temperature plays a major factor due to diurnal solar radiation variation, and its disturbance nature, with the frequent startup and shutdown of STP, is avoided. In this paper, the PTC component is modeled from the first principle, and, with different HTF, the performance of PTC with constant and quadratic solar disturbances is analyzed along with classical control system designs. Through this, the operator will be able to choose proper HTF and resize the plant components depending on plant location and weather conditions. Furthermore, the thermal energy is collected for therminol oil, molten salt, and water; and its performance with different inputs of solar radiation is analyzed along with closed-loop controllers. Thermal energy extracted by therminol oil, molten salt, and water with constant solar radiation results in 81.7%,73.7% and 18.7%, respectively.

Thermal performance enhancement in parabolic trough solar collectors by using an absorber tube with spherical pins

ABSTRACT Improving the overall performance of parabolic trough collectors (PTCs) represents the best method to reduce the cost of energy produced. The goal is to increase their potential to generate more useful heat, particularly at high ranges of temperatures. Therefore, various techniques have been thoroughly examined in the literature. Indeed, the non-uniform heat flux on the PTC receivers induces overheating of the absorber tube and significant thermal stress, which requires the use of expensive materials. It also reduces the overall thermal performance of the system. To overcome these issues, practical solutions must be introduced. In this paper, integrated spherical pins are used and different configurations have been proposed and investigated. To do so, a numerical model that combines optical and thermal aspects has been developed. For this, the Monte Carlo ray tracing technique (MCRT) is coupled with the finite volume method (FVM). Also, experimental tests on the MicroSol-R platform have been used to validate the numerical models. A number of energetic and exergetic performance indices are used to analyze the potential improvements due to the use of spherical pins. The analysis showed that the use of pins increases the heat transfer coefficient by up to 27.2% and reduces the heat loss by up to 9.32% compared with conventional smooth tubes. Moreover, it is found that the performance evaluation criterion (PEC) can be enhanced by up to 24.92%. Consequently, when using a solar receiver with five pins (which was selected as the best configuration among the examined configurations), the overall efficiency and the exergetic efficiency are increased by up to 4.1% and 2.2%, respectively. Indeed, the use of pins inside the solar receiver is a practical solution to improve the efficiency of the PTC system and has the potential to reduce the thermal stress on the receiver thanks to the high heat transfer coefficient. It also helps prevent overheating and reduce thermal losses by keeping the maximum temperature within a suitable operational range.

Performance of parabolic trough collector having rotating receiver: Effect of elliptical insert and hybrid nanofluid

This study considers three parabolic trough collector models with rotating receiver tubes and elliptical inserts of two orientations and one with a smooth receiver tube. Hybrid nanofluid is considered as a working medium by mixing copper oxide and aluminum oxide nanoparticles in water. Computational experiments are performed with a 1% concentration in terms of vol. of hybrid nanofluids by considering a mixture of copper oxide and aluminum oxide nanoparticles in water (aluminum oxide 25%- copper oxide 75%, aluminum oxide 50%- copper oxide 50%, and aluminum oxide 75%- copper oxide 25%). Rate of flow for the simulation is considered to vary from 0.016 to 0.033 kg/s. Again, this study focuses on utilizing rotating receiver tubes with a varying velocity of 0-15 rad/s to overcome the stratification of high temperature at the surface. Results show that enhanced values for the temperature at outlet, heat transfer coefficient, and thermal efficiency are noted for a model with elliptical inserts of major diameter 28 mm (longitudinal orientation) at 15 rad/s receivers speed for nanofluid-1 (aluminum oxide 75%- copper oxide 25%) at 0.033 kg/s. The highest increment in heat transfer coefficient, as well as thermal efficiency for the model with a 28 mm major diameter elliptical insert (longitudinal orientation), is 44.21% and 29.21% respectively. Highlights Use of a spinning receiver reduces the problem of uneven temperature distribution at receiver surface. Maximum 375 K outlet temperature is noted at 15 rad/s for elliptical insert of diameter 28 mm (longitudinal orientation) at 0.016 kg/s. The elliptical insert received the maximum thermal efficiency rating of 82.03%. An elliptical insert in receiver increases pump work by 18.13% than smooth receiver.

Experimental and modelling investigation on the effect of inserting ceria-based distilled water nanofluid on the thermal performance of parabolic trough collectors at the weather conditions of Amman: A case study

This experimental study investigated the performance of two identical parabolic trough collector (PTC) systems using nanofluid CeO2/H2O and distilled water as working fluids under the weather conditions in Amman and various nanofluid concentrations. Two identical manufactured PTC were tested under the mass flow of 0.7 L/min. One of the identical PTC was used in water as a thermal fluid, and the second one was the ceria nanofluid under four diluted volume concentrations, namely, 0.01%, 0.03%, 0.06%, and 0.1%. At the beginning of the tests, the identical PTC were tested using distilled water to ensure that they had approximately the same thermal efficiencies. Results were evaluated under a volume flow rate of 1.2 L/min and the deviation and the average thermal efficiency between them showed low variance, not exceeding 0.4%. Furthermore, during the tests, which were conducted on various days in July 2021 between 10:00 a.m. and 2:00 p.m., both collectors’ direction was tracked using a digital tracking system to guarantee that solar radiation remained perpendicular to the region of the PTC. In addition to the nanofluid preparation and stability checking, the thermal efficiency of the PTC was investigated for various ceria nanofluid concentrations compared with the distilled water. The results showed that the maximum thermal efficiency was obtained for 0.1% volume concentration of CeO2 nanofluid and reached 18.03%, and it reached 17.15%, 16.11% and 14.40% for 0.06%, 0.03% and 0.01% volume concentrations of CeO2 nanofluid, respectively; it reached 11.71% for water. The maximum optical thermal efficiency was enhanced by increasing the concentrations, where the maximum enhancement value of 47.7% was observed using 0.1% volume concentration. Finally, the experimental results for different cases have been compared with the Solidwork simulation, which was developed to obtain the outlet temperature and thermal performance of the PTC. The comparison results showed high accuracy, where the average thermal efficiency did not exceed 2.19%, and the outlet temperature did not exceed 0.10%.

Experimental and Theoretical Study of Parabolic Trough Solar Collector Performance Without Automatic Tracking System

In this research, a practical and theoretical study was conducted to evaluate the performance of parabolic trough collectors (PTCS) of length (3 m) and width (2.67 m) for three solar collectors connected in parallel, and the absorber tube is made of stainless steel with an internal and external diameter (0.028 m), (0.031 m), respectively. The absorber tube of length 11 m, was painted with un shiny black paint to increase the absorption of sunlight and reduces the thermal radiation. The working fluid is transferred through the receiver tube and located at the focus area of the three collectors. The collector width aperture width was 0.8 meters, and 2.40 meters length with rim angle of Ø = 90°, and concentration ratio of 8.02. The collector surface was covered with aluminum foil which is available in the local market (3M SA-85), which covers galvanized iron sheets with a thickness of 2 mm. A computer program in Fortran language was built to calculate the performance of the solar collector. Experimental results of the test showed that the performance factor of the solar collector is less than the typical type, where notes that there is a large deviation between the theoretical and experimental results, especially in the winter, where the deviation in the morning at ten o'clock about 78%, while it was 5% at noon. The large deviation value mentioned resulting from the assumptions that have been developed to simplify the equations that were used in the theoretical side of research, also the reasons that the theoretical results are taken on the assumption that weather conditions are clear sky and that contrary to reality in the winter. ةThe best efficiency of the solar collector was between solar time (12:00) and time (1:00) at night for two seasons, and the obtained results showed that the increase of mass flow rate of fluid from the amount of (0.033) kg/sec to the amount of (0.066) kg/sec increases the efficiency of solar collector, but leads to reduce the temperature difference between the inlet and exit, as well as the results showed that an increase in solar flux increases the useful energy obtained from the solar collector.

EXPERIMENTAL OPTIMIZATION AND CFD MODEL VERIFICATION OF THE PARABOLIC TROUGH COLLECTOR WITH A STAGGERED BUTTERFLY FINNED PIPE INSERTS

In recent years, the exploitation of energy resources at limits has sought an answer to the question how renewable energy could be used more efficiently. The aim of this study is to increase the thermal performance of parabolic trough collectors (PTC) by optimizing the system parameters by using response surface methodology (RSM). A staggered butterfly finned turbulator designed and manufactured specifically for the PTC system was used to improve heat transfer through the pipe. Efficiency was chosen as the response variable. The effects of the spacing of the turbulator fins, Reynolds number, and solar irradiance were investigated by the RSM. As a result, optimum values for thermal efficiency were obtained to be 9.44 cm for turbulator fin spacing, 821.21 for the Reynolds number, and 875.75 W/m2 for solar irradiance. A CFD analysis was performed for the verification of the optimum results obtained, which revealed good agreement between the optimum values obtained experimentally and the results of the numerical analysis. In addition, an experimentally validated mathematical model represented by independent parameters is presented.

Influence of reflector installation errors on optical-thermal performance of parabolic trough collectors based on a MCRT - FVM coupled model

A three-dimensional optical-thermal model of parabolic trough solar collector (PTC) based on Monte Carlo Ray Tracing (MCRT) method and Finite Volume Method (FVM) was proposed. The simulation results are compared with experimental data to verify the feasibility and reasonability of the model. The model was used to analyze the effect of reflector installation errors on PTC performance. The results showed that the optical efficiency of about 82.61% and the collector efficiency of approximately 68.22% can be maintained if the reflector installation error (θ) is kept lower than 7 mrad. Compared with the case of unilateral installation error, the optical efficiency and the collector efficiency caused by bilateral installation error decrease faster as reflector installation error increased when the θ > 7 mrad. The increase of the peak value of the local concentration ratio (LCR) is observed under the conditions of θleft = 0, θright = θ and θright = -θleft = θ compared with the non-deformation case, indicating that the receiver may occur local overheating, which may shorten the service life of the receiver. Among them, the bilateral error with a geometry of θright = -θleft = 7 mrad damages the optical performance and thermal performance of PTC more seriously.

Effects of Receiver Misalignment on the Intercept Factor of Parabolic Trough Collectors

Abstract This study developed a methodology for determining the intercept factor (γ) and reports the effects of varying the design parameters, within realistic ranges, on the optical performance of parabolic trough collectors (PTC). The design equations account for the aperture width of the concentrator, the geometric concentration ratio, rim-angle, and misalignment of the receiver, characterized by the radial and angular offsets. The Latin Hypercube Sampling (LHS)-based ray-tracing method was used. Validation of the method was performed by comparing the results obtained by tracing a single ray with measurements obtained in a two-dimensional (2D) drafting program. Then, parametric analyses were performed to determine the effects of changing the radial and angular offset, geometric concentration ratio, and rim-angle on the percentage change in intercept factor (γΔ) with respect to the γ of a PTC with a perfectly aligned receiver. Finally, contour plots depicting the γ of various standard troughs over the range of radial and angular offsets were plotted, compared, and discussed. An online tool is also presented to help designers and researchers analyze these effects quickly by providing the design parameters.

Thermal Performance Comparison of Parabolic Trough Collector (PTC) Using Various Nanofluids

The objective of this paper is to investigate the theoretical performance of Parabolic Trough Collector (PTC) using various nanofluids. The theoretical performances are calculated for Al2O3, graphite, magnetite, SWCNH, CuO, SiO2, MWCNT, TiO2, Fe2O3, and ZnO in water nanofluids. The heat transfer equations, thermodynamic properties of nanofluid and pumping power are utilised for the development of novel thermal model. The theoretical thermal efficiency of the PTC is calculated, and the economic viability of the technology is predicted for a range of nanofluid concentration. The results showed that the thermal conductivity increases with the concentration of nanoparticles in the base fluid. Magnetite nanofluid showed the highest thermal efficiency, followed by CuO, MWCNT, ZnO, SWCNH, TiO2, Fe2O3, Al2O3, graphite, and SiO2, respectively. The study reveals that MWCNT at 0.4% concentration is the best-suited nanofluid considering thermal gain and pumping power. Most of the nanofluids achieved optimum efficiency at 0.4% concentration. The influence of mass flow rate on thermal efficiency is evaluated. When the mass flow rate increased from 70 Kg/hr to 90Kg/hr, a 10%-20% efficiency increase is observed. Dispersing nanofluids reduces the levelized cost of energy of large-scale power plants. These findings add to the knowledge of the scientific community aimed explicitly at solar thermal energy technology. The report can also be used as a base to pursue solar thermal projects on an economic basis.

Multi-objective optimization and energy/exergy analysis of a ternary nanofluid based parabolic trough solar collector integrated with kalina cycle

The utilization of solar thermal collectors has increased significantly in the last decade. The heat transfer fluids that is used in the design of these systems has notable effects on their performance. The recent discoveries of hybridized nanofluids, give a promising approach for investigating the performance of parabolic trough collectors (PTC), especially at different design conditions and environmental parameters. This study investigates the thermodynamic performance of a Kalina cycle incorporated with a parabolic trough collector that utilizes ternary nanofluid as a heat transfer fluid. The use of mono, hybrid and ternary nanofluids (THNF) in the parabolic trough collector is examined based on their impact on the efficiency of thermal system. The nanofluids considered are Al 2 O 3 , Al 2 O 3 –Fe, Al 2 O 3 –ZnO, and CuO–MgO–TiO 2 . The performance of integrated cycle based on the effect of solar irradiation and volume fraction of the nanofluids are studied and compared with conventional fluids namely: thermal VP1 oil, DowThermal oil, and Salt (7NaNO 3 , 40NaNO 2 , 53KNO 2 ). In addition, an optimization study is conducted using genetic algorithm to maximize the net power output of the Kalina cycle and the exergetic efficiency of overall system. The results showed that performance of the system which uses nanofluids as a working fluid was higher than the systems using conventional fluids. Furthermore, the results demonstrate that maximum net power output of the system is recorded when Al 2 O 3 , Al 2 O 3 –Fe, Al 2 O 3 –ZnO, and CuO–MgO–TiO 2 nanoparticles are used. The power outputs were evaluated as 59.72 kW, 56.64 kW, 54.54 kW, and 61.21 kW respectively. The optimization study reveals that the optimum exergetic efficiency when Al 2 O 3 , Al 2 O 3 –Fe, Al 2 O 3 –ZnO, and CuO–MgO–TiO 2 nanofluids are used can reach up to 21.0%, 17.2%, 10.8%, and 25.1% respectively. • The effects of nanofluids on PTC/kalina is examined. • Effects of volume fraction, solar radiation and temperature is analyzed. • Optimum exergy efficiency measured is for CuO-MgO-TiO2 at 25.1%.

Influence of the concentration ratio on the thermal and economic performance of parabolic trough collectors

The thermal and economic performance of parabolic trough collectors (PTCs) and PTCs with double glass envelope (DGE-PTCs) are analyzed in this work. A model including thermal and optical effects is developed to evaluate the efficiency of vacuum and air-filled DGE-PTCs, while an economic model based on two commercial PTCs (SkyTrough and Ultimate Trough collectors) was developed to assess the economic performance. The efficiency and thermal output per unit cost of the proposed DGE-PTCs are analyzed as a function of the concentration ratio and are respectively compared with the thermal and economic performance of traditional and commercial PTCs. The optimum concentration ratio for maximum thermal performance varies from 11.0 to 23.3 for operation temperatures (THTF) between 100 °C and 400 °C, while the optimum concentration ratio for maximum economic performance ranges between 28.9 and 33.2 for the SkyTrough and between 40.0 and 43.8 for the Ultimate Trough collector designs. The DGE-PTCs present higher thermal and economic performance at high operating temperatures, which presents a valuable opportunity for implementation in new PTC designs pursuing higher operating temperatures to achieve superior thermal cycle efficiencies.

Improvement of the thermal and hydraulic performance of parabolic trough collectors using hybrid nanofluids and novel turbulators with holes and ribs

In this study, innovative methods to improve the thermal efficiency and hydraulic performance of parabolic trough collectors are presented by locating different turbulators in the tube and adding hybrid nanofluids with volume percentage of 0, 2, and 4. The Eulerian scheme and Phase Coupled Simple method are employed for hybrid nanofluids. A novel turbulator with holes and ribs is employed to improve the thermal and hydraulic efficiency of parabolic trough collectors. Two types of turbulators with three values of turn = 0.3, 0.5, and 0.7 are used in these simulations. In the first turbulator, about 50.5% increase in thermal efficiency is achieved while the volume fraction of nanoparticles, Reynolds number, and turn are minimum. In maximum and minimum conditions, an increase in the mean Nusselt number for the second type of turbulator is equal to 44.6%. At maximum conditions, the value of the heat index number in the second type of turbulator is about 3.3% higher than that in the first one. This research suggests an appropriate perspective to increase the thermal and hydraulic efficiency of parabolic trough collectors by adding novel turbulators and employing hybrid nanofluids.

Performance investigation of the organosilicone conduction oil with CuO nanoparticles filled in twist tube flow for solar energy storage

A regular polygon twisted tube with CuO nanoparticles distribution in the organosilicone conduction oil is adopted to improve the thermal performance of parabolic trough collectors (PTCs). A comprehensive numerical study is applied to invistigate the thermal performance of 21 kinds of wisted tubes under the Reynolds number ranging from 50 to 102000 when the temperature is 450 K. The novel twisted tubes are considered with the number of twisted tube edges varying from 1 to 8 and twist angle per unit length varying from 0° to 360°. Results show that the thermal performance of PTC can be enhanced obviously by the nanoparticles. The thermal efficiency enhancement increases with the increasing twist angle, and reaches up to about 306% compare with that for the smooth circular tube. A great effectiveness and uniform performance near the wall region is obtained with the designed complex method. The case of twist angle θ =360° has a better thermal performance when it is compared with the ones with other twist angle. The case of twist angle θ=270° with Reynolds number ranging from 3300 to 12200 has a better comprehensive energy-saving performance when it is compared to the cases with other twist angles. At the same heat transfer capacity, the energy consumption is reduced by 50%.

A Hybrid Nanofluid of Alumina and Tungsten Oxide for Performance Enhancement of a Parabolic Trough Collector under the Weather Conditions of Budapest

Recently, there has been significant interest in the thermal performance of parabolic trough collectors. They are capable of operating and generating highly variable temperature ranges, which can be used in various applications. This paper, therefore, addressed the thermal performance model of using a parabolic trough collector under the radiation intensity level found in Budapest city, as well as the effect of inserting a hybrid nanofluid as the thermal fluid. First, a new modified hybrid nanofluid of alumina and tungsten oxide-based Therminol VP1 is used to enhance the thermal properties of the thermal fluid to be more efficient to use. This enhancement is performed under various volume concentrations and has a volume fraction of 50:50. Second, in order to demonstrate the effectiveness of the thermal element, mathematical energy balance equations were solved and simulated using MATLAB Symbolic Tools. The simulation is presented for two cases: one under a constant radiation intensity and the other under the radiation intensity level of Budapest. For both cases, the results of the dimensionless Nusselt number, heat transfer coefficient, pressure drop, exergy efficiency, and energy efficiency are described. The major findings show that a volume concentration of 4% (Al2O3 and WO3) based Therminol VP1 was the most efficient volume concentrations in both cases. For the first case, the maximum enhancement of the Nusselt number and the heat transfer coefficient are 138% and 169%, respectively. These results enhanced the thermal and exergy efficiencies by 0.39% and 0.385% at a temperature 600 K, flow rate of 150 L/min, and radiation intensity of 1000 W/m2. For the second case, the maximum exergy and energy values are recorded at midday under Budapest’s summer climatic conditions and reach 32.728% and 71.255%, respectively, under the optimum temperature of 500 K and flow rate of 150 L/min. Accordingly, the mean improvement in thermal and exergy efficiencies approximately equal to 0.25% at a high concentration, regardless of the season (summer or winter).

Energy and Exergy Performance Comparative Analysis of a Solar-Driven Organic Rankine Cycle Using Different Organic Fluids

Abstract In this study, the performance of parabolic trough collector (PTC) integrated with an organic Rankine cycle (ORC) is investigated to find the optimum operating scenarios and to assess the exergy destruction at different components of the system. A commercial PTC LS-2 model with Therminol VP-1 as heat transfer fluid was integrated with an ORC that was examined for its thermal and exergetic performance using different organic fluids. It was found that every fluid has an optimum pressure and temperature level at which it works better than other fluids. R134a (tetrafluoroethane, CH2FCF3) showed the best performance for the turbine inlet temperature range from 340 K to 440 K regarding the achieved energy and exergy efficiencies. At a temperature of 362.8 K and a pressure of 2750 kPa, R134a showed the highest energy efficiency of 8.55% and exergy efficiency of 21.84% with the lowest mass flowrate required in ORC. Energy efficiency of other fluids, namely, R245fa (pentafluoropropane, CF3CH2CHF2), n-pentane, and toluene, was less than 5%. On the other hand, toluene exhibited thermal efficiency of 23.5% at a turbine inlet temperature of 550 K and a pressure of 2500 kPa, while the exergy efficiency was 62.89% at solar irradiation of 1 kW/m2.

Comprehensive review on various parameters that influence the performance of parabolic trough collector.

Among the different kinds of renewable energy sources, solar energy plays a major role because it is safe and inexpensive at all times. Several techniques are developed for steam and electricity generation by solar energy, in which the parabolic trough collector is an advantageous method for generating steam and electricity. Different types of collectors for various temperatures, in which PTCs are used to produce medium temperature ranges using the readily available solar energy, were developed, produced, and tests. Many theoretical and experimental studies have been carried out to improvise parabolic trough collectors' optical and thermal characteristics. The modifications are reviewed in this paper to enhance the design modification, optical and thermal properties utilized in the collector. This analysis paper also elucidates the use of PTC desalination, various integrated parabolic trough collector methods for power generation, and the economic aspects of parabolic trough collector.