In this investigation, an improvement strategy for a photovoltaic (PV) system is examined, incorporating a nanofluid filter and a paraffin-based storage system. The utilization of a spectral filter, employing ZnO-water nanofluid, is intended to optimize the utilization of the entire spectral distribution of sunlight. In all scenarios, a paraffin layer is introduced, comprising RT25 mixed with ZnO nanoparticles. Moreover, the consideration is given to the influence of applying TiO2 nanoparticles for coating the upper glass layer. The investigation utilizes simulations based on the finite volume method and examines four unique scenarios: case 1, characterized by the absence of a filter; case 2, involving the incorporation of a nanofluid filter; case 3, incorporating dusty glass with a filter; and case 4, integrating a self-cleaning effect with a filter. Examining various performance metrics uncovers significant findings. The research showcases a 5.3 % rise in CO2 mitigation (CM) through the integration of a nanofluid filter, a 12 % reduction linked to the influence of dust, and an 11.2 % enhancement facilitated by a self-cleaning method. The presence of dust initially contributes to a decrease in outlet temperature of the filter (Tout), but eventually, it exhibits a 66.79 % improvement with the adoption of the self-cleaning method. The application of a coating on the glass layer leads to an 11.2 % boost in electrical performance (eta el). Utilizing filter results in a decrease of 19.08 % in temperature of paraffin (TPCM) and 8.54 % in liquid fraction (LF), while concurrently enhancing eta el by 5.03 % at t = 80 min. Three cities have been analyzed in terms of profit after 12 years, with Berlin showing the highest returns. For Berlin, implementing the spectral filter increases the system's profit by approximately 5.34 %, while coating the glass with nanoparticles further boosts it by about 18.12 %.

This study investigates a comprehensive enhancement strategy for photovoltaic (PV) panel efficiency, focusing on increasing electrical output through the integration of parabolic reflectors, advanced cooling mechanisms, and thermoelectric generation. Parabolic reflectors are implemented in the system to maximize solar irradiance on the PV panel’s surface, while a specialized cooling system is introduced to regulate temperature distribution across the silicon layer. This cooling system consists of a finned duct filled with paraffin (RT35HC) and enhanced with SWCNT nanoparticles, which improve the thermal properties of the paraffin, facilitating more effective heat dissipation. The PV module is also integrated with a TEG (thermoelectric generator) to capture excess thermal energy and convert it into additional electrical power, allowing for a more efficient overall system. To simulate the heat flux introduced by the reflectors, SolTrace software was employed, while the unsteady, three-dimensional thermal behavior of the system was analyzed using ANSYS FLUENT. Simulated results demonstrated that, with the cooling system in place, the PV efficiency (ηel, PV) improves by approximately 16.46% in clean conditions. However, dust accumulation on the panel significantly impacts performance, reducing ηel, PV by around 46.48% after 60 min. The inclusion of fin structures further optimizes the system, boosting overall efficiency by approximately 6.77% in clean conditions and 3.78% under dust-affected conditions. Additionally, thermal efficiency for the clean state increased by about 8.47% due to the fins. Notably, the combined effects of parabolic reflectors, fin-enhanced cooling, and TEG integration yield an electrical output power approximately 2.94 times greater than that of a PV panel without any reflector or cooling modifications.

In the current study, an evacuated solar collector with sinusoidal U-pipes filled with paraffin was investigated for energy saving. To generate electricity in addition to storing thermal energy, thermoelectric generator (TEG) was integrated into the unit. The paraffin was enhanced with hybrid nanoparticles composed of silver (Ag) and titanium dioxide (TiO2) to improve thermal conductivity. Additionally, innovative fin shapes were employed to accelerate the melting process, and various fin arrangements were tested. A numerical technique was utilized to model the process, and the outputs showed good agreement with previous study, confirming the accuracy of the simulations. The study aimed to identify the optimal geometry for the solar energy system. The best-performing configuration included two sinusoidal U-pipes and four inclined fins, in contrast to the base case, which featured circular U-pipes without fins. For the optimal geometry, the liquid fraction (LF) and paraffin temperature (TPCM) increased by 47.38 % and 1.16 %, respectively, over time. At 45 min, with all enhancements applied, LF and T PCM improvements reached 52.21 % and 2.63 %, respectively. The integration of the TEG module allowed the system to produce electricity while storing thermal energy, although the efficiency of the TEG decreased by about 3.5 % due to the modifications. The modified solar system achieved an electrical output of 7.15 kW. By integrating sinusoidal U-pipes, hybrid nanoparticles, and novel fin designs, the study significantly improves thermal energy storage and electricity generation.

This study aims to optimize a solar Photovoltaic (PV) and thermoelectric (TE) unit utilizing the Non-dominated Sorting Genetic Algorithm II (NSGA-II). The system incorporates a hybrid nanofluid jet, composed of water and ND-Co3O4 nanoparticles. Optimization, conducted in Python, utilizes data from an extensive 3D numerical model. Key factors under consideration include solar irradiation, the jet’s injection location, tube and jet inlet velocities, and the proportion of hybrid nanoparticles. The primary goals are to reduce pumping power (Ep), maximize the system’s overall gain over a 10-year span, and improve CO2 reduction. This research is significant for its comprehensive approach to enhancing solar energy technology, boosting system performance and efficiency, while addressing environmental concerns by lowering CO2 emissions. By combining advanced numerical simulations with NSGA-II optimization, this work advances sustainable energy solutions, providing valuable insights for the design of well-organized and environmentally friendly solar energy units. The optimization successfully balanced system gain, CO2 reduction, and pumping power, achieving optimal results of $12,508.8 for system gain, 431.59 tons for CO2 reduction, and 0.2097 for pumping power. The Mean Squared Error (MSE) percentages for the training data are under 1% for system gain, approximately 1.6% for CO2 reduction, and around 1.1% for pumping power, underscoring the effectiveness of the optimization process.

This article introduces an innovative integration of a thermoelectric generator (TEG) module with a U-tube evacuated solar system, using paraffin as the phase change material (PCM). To enhance the PCM's melting rate and improve the system’s overall thermal efficiency, three advanced strategies were employed: (1) The addition of ternary nanoparticles—comprising MgO, ZnO, and MWCNT—into the paraffin to boost thermal conductivity; (2) Modification of the U-tube's geometry from a circular to a three-lobed design for improved heat transfer; and (3) The installation of tree-shaped fins to optimize heat distribution and accelerate the melting rate. The unsteady thermal behavior has been modeled using the finite volume method. The results demonstrated that these techniques significantly increased the melting rate and thermal efficiency, though they led to a slight decrease in the TEG's electrical power output. Four configurations were examined: (Case 1: Circular U-tube with pure paraffin; Case 2: Three-lobed U-tube with pure paraffin; Case 3: Three-lobed U-tube with ternary nanofluid; Case 4: Three-lobed U-tube with ternary nanofluid and tree-shaped fins). The incorporation of ternary nanoparticles accelerated the melting process, increasing the charging rate by 3.47 % at 150 s and 1.92 % at 450 s. Replacing the circular U-tube with a three-lobed design, combined with ternary nanomaterials, improved the liquid fraction by 57.76 % at 150 s and 22.28 % at 450 s. When all three techniques were applied together, the temperature of the system rose by 6.14 % at 150 s and 4.57 % at 450 s. However, in case 4, a decrease of 3.23 % in the TEG’s efficiency was observed at 900 s, yielding an electrical output of 2.28 kW.

Efficiently harnessing solar energy and optimizing photovoltaic panel performance is essential for addressing the energy challenge. This study introduces an innovative approach that integrates cooling fluids and Phase Change Materials (PCM) enhanced with nanoparticles such as ZnO, SiC, Al2O3, and Cu at a volume fraction of 0.03 to improve electrical output. Key components of this advanced cooling design are nanofluids and Nano-Enhanced PCM (NEPCMs). The research begins by selecting and evaluating three distinct NEPCMs to establish a comprehensive ranking. It then investigates the potential for increased electrical efficiency by integrating a thermoelectric module to boost panel output power. The study tests how fluid velocity impacts cooling efficiency, revealing the complex interplay between fluid dynamics and cooling performance. This integrated system successfully reduces panel temperatures from 359.51 K to 321.91 K, leading to a 15.01 % increase in overall electrical efficiency over a six-hour period, generating 0.42 kW-hours (kWh) of power during daylight hours. The inclusion of porous materials, particularly aluminum foam in the PCM region for both finned and finless designs, significantly enhances heat transfer. The findings indicated the significant improvement in electrical performance (13.92 %) for finned configurations. Additionally, the calculated Carbon Credits Earn (CCE) value enhances system profitability to $313,439.778.

Background: This work introduces an innovative configuration for intensifying the productivity of solar photovoltaic-thermal units (PVT) through the incorporation of a cooling system. Notably, a thermoelectric module is strategically added to further intensification of produced electricity. Methods: This unit has a duct where the hybrid nanofluid passes through which a turbulator is placed. Furthermore, this system has a jet impingement component. In a departure from traditional methodologies, this investigation optimizes the PVT unit's overall effectiveness by employing an algorithm based on machine learning. Three critical goal functions are considered in this optimization process: Ep (pumping power), CO2 - m (CO2 mitigation), and Profit of the system, each of which respectively represents the generated electrical energy for energy analysis, the reduction of produced carbon for environmental evaluation and the financial gain from employing the present system for economic assessment. This innovative approach not only contributes to advancing the field of solar photovoltaic-thermal systems but also underscores the importance of optimizing these units for increased energy efficiency, reduced environmental impact, and enhanced economic viability in the context of renewable energy technologies. Significant findings: The connections between the PVT's variable mappings, comprising the input parameters of the fluid velocity (VTube), solar radiation (G), jet impingement velocity (VJ), and helical tape ratio (R) and the outputs of the Ep, Profit, CO2 - m, are established through the implementation of various models. The findings suggest that the GPR (Gaussian Process Regression) model is the most appropriate, as evidenced by its R2 values of 0.9987, 1, and 1 for Ep, Profit, and CO2 - m, correspondingly. The NSGA-II technique is utilized in this study. This procedure is used to ascertain the Pareto optimal solutions with respect to all three conflicting objectives. The outcome illustrates the Pareto graphs, and each of them in provides a suitable compromise between all objectives without degrading any of them.

The urgent need for electricity generation for both commercial and residential uses can be satisfied by photovoltaic units, but the serious flaws of these units arise from the negative effects of environmental factors like dust, shadow, radiation, and wind on their performance. The present study examines how PV panels operate under dusty conditions, using ANSYS FLUENT software and focusing on steady-state and laminar conditions. This study aims to numerically examine a three-dimensional (3-D) photovoltaic thermal (PV-T) unit with sinusoidal walls (PV-T-SW). The testing fluids examined in current paper are Al2O3-H2O nanofluid and H2O. Under the same initial and boundary conditions, three configurations were tested: a PV module, a straight channel PV-T unit, and the PV-T-SW, which are numerically compared and examined. An important element that declines the power generation efficiency is the deposition of dust on photovoltaic panels. The key novelty of the current study is that it provides a numerical modeling of the impact of dust in the presence and absence of a self-cleaning coating on a photovoltaic thermal system, as well as the optimal cooling mode and configuration. First, suitable temperature management systems are critical for achieving high-efficiency solar photovoltaics, and in heat exchange devices, the employment of corrugated structures has proven to be a helpful strategy because of the benefits of extended surface area. Finally, the electrical (eta ele) and thermal (eta th) efficiency are assessed by taking into account the optical properties of dust deposition and hydrophobic coating. The factors evaluated are the impacts of varying nanofluid concentration, inlet flow Reynolds number (ranging from 500 to 1500), wavy channel amplitude, and wavelengths on cooling performance. The findings revealed that using 4 % water-aluminum oxide as an operating fluid instead of H2O improved the coefficients of heat transfer in the channel by 15.7 %. In addition, at the next step, when water-aluminum oxide was used as a coolant and the sinusoidal channel was examined with different geometrical characteristics, it was discovered that the 9 mm wavelength and 0.8 mm amplitude channel, in comparison to the simple form of the system, had superior heat transfer performance. Furthermore, the obtained data indicate that the eta ele decreased by 40 % as the dust deposition happens, and it was discovered that the coating reduced that negative effect on the glass used to cover solar cells. Because of rising environmental issues and the expense of energy, thermal control of sources of energy that are renewable is becoming more and more important. The findings of this investigation can be used for future PV cooling innovation unit development and optimization.

The energy conversion performance of commercial photovoltaic (PV) systems is only 15–20 percent; moreover, a rise in working temperature mitigates this low efficiency. To enhance their performance and prevent damage, researchers test new technologies and integrate heat recovery devices with PV systems. Concentrated photovoltaic systems (CPVs) are especially vulnerable to high radiation levels. This paper explores novel cooling techniques for PV systems, an area that has not been extensively investigated before. The cooling methods are categorized into front-surface and back-surface cooling methods, offering a unique perspective on how to keep PV systems cool. Moreover, the paper delves into the advancements made in PV cooling systems and CPVs, shedding light on the cutting-edge developments in this field. The results demonstrate the profound impact of various operational factors, such as radiation and wind speed, on the selection of suitable cooling systems or heat recovery methods. These findings unveil the crucial importance of considering these factors when choosing cooling techniques, adding a compelling dimension to the research. For example, it was depicted that optical cooling techniques can enhance the performance of PV systems by up to 4.2

In this work, for decreasing the irreversibility of system and augmenting the thermal performance, hybrid nanomaterial was utilized as testing fluid inside the pipe of concentrating solar unit with presence of complex disturber device. The base fluid for this domestic usage is water and concentration of each nanoparticle is 0.01, thus, assumption of homogeneous fluid is correct. After finding the best position and angles of minors as primary concentrator, Monte-Carlo method has been incorporated to measure the outer wall's boundary condition. Then, FVM was hired for 3D modeling of hybrid nanofluid flow with incorporation of k-ε technique. As hybrid nanoparticles have been dispersed into water, the pressure drop and frictional irreversibility (Sgen,f) augment around 7.98% and 5.02% while heating irreversibility (Sgen,h) declines around 4.01% when BR= 0.24, PR= 0.15, Q= 15. Increase of PR leads to greater mixing and Sgen,f augments around 74.3% due to augment of swirl flow but Sgen,h decreases about 47.41%. Considering higher Q can augment the radial velocity and stronger resistance with wall leads to increase of Sgen,f about 357.21% whereas Sgen,h reduces about 81.56%.

This research investigates the enhancement of photovoltaic (PV) solar panel performance through the application of a paraffin-based spectral splitter. The study aims to improve electrical efficiency and thermal management while mitigating dust deposition effects. A paraffin (RT25) spectral filter is placed above the glass layer of the PV panel, coupled with a ZnO-water nanofluidfilled mini-channel for cooling at the panel's bottom. Optical properties, derived from previous experimental work, are incorporated into simulations. Self-cleaning SiO2 nanoparticle coating is proposed to improve transmissivity of upper glass. Fresnel lens is used to intensify irradiation at two concentration ratios (CR). Three-dimensional simulations integrating source terms based on optical analysis were conducted. Key findings include a decrease in panel temperature (TPV) due to partial irradiation absorption by the spectral filter, leading to lower heat flux to the cooling zone. The spectral filter increased electrical efficiency (eta PV) by 11.28 % and 38.63 % at 20 and 40 min, respectively. The presence of the filter and coatings significantly improved temperature uniformity, with improvements of 68.77 % and 50.35 % at 10 and 40 min, respectively. Increasing CR resulted in a 2.95 % and 83.31 % rise in filter temperature (TPCM) and liquid fraction (LF), with a minor 1.56 % decrease in efficiency. At CR = 2, in the presence of the spectral filter, eta PV decreases by 38.62 %, accounting for dust effects, while it increases by 21.83 % with adding coating. The research highlights the potential of spectral filters and innovative coatings to enhance PV panel performance, offering a novel approach to sustainable and efficient solar energy systems.

The importance of studying photovoltaic thermal (PVT) systems is underscored by their potential to harness both solar thermal and photovoltaic energy simultaneously, making them a promising avenue for sustainable power generation. The integration of a PVT system allows for enhanced energy conversion and utilization of available resources. In the context of the broader field of renewable energy, understanding and optimizing PVT systems contribute to the development of efficient and environmentally friendly power generation solutions. The introduction of CuO nanoparticles proves beneficial, contributing to an overall improvement in system performance. Throughout this exploration, the aim is to provide insights into the intricate dynamics of PVT systems under varying conditions, emphasizing the impact of key parameters on system efficiency and performance. Examining PVT systems, this study focuses on a rectangular duct equipped with a turbulator featuring rectangular cuts. The simulation considers the flow of CuO-H2O within the channel and accounts for pure conduction within the layers, employing the finite volume method with a validation test for accuracy. The mesh size has been optimized for computational efficiency. In this context, the study investigates variations in cell temperature (TPV) and efficiency components (electrical (eta PV), thermal (eta th), overall (eta PVT)) concerning key variables: wind speed (Vw (0.4, 1, 1.4 m/s)), incident irradiation (G (730, 830, 930 W/m2)), inlet velocity (0.08, 0.1, 0.12 m/s), volume fraction of CuO (phi = 0, 0.018). Introducing the turbulator improves TPV uniformity by about 20.43%. With increased incident irradiation in the presence of the turbulator, eta PV, eta th, and eta PVT values enhance by approximately 1.02%, 8.18%, and 4.99%, respectively. Specifically, at G = 930 W/m2, the turbulator installation leads to a 4.35% increase in eta PVT. However, certain variables demonstrate contrasting effects. Increased wind speed results in a 3.63% decrease in eta PVT for tubes equipped with a turbulator. Conversely, intensifying the inlet velocity leads to an augmentation of eta PVT by around 3.19%, coupled with a notable 16.34% improvement in the uniformity of TPV.

This study explores a solar concentrated unit with a parabolic concentrator. The evacuated region between the glass and absorber is incorporated, and for modeling purposes, the discrete ordinates (DO) method is utilized. The working fluid contains a mixture of Syltherm 800 and hybrid nanoparticles (CNT + SiO2). The heat flux absorbed by tube is derived from experimental work and applied as a heat source within the solid layer of the absorber. A new shape of turbulator is used to enhance the swirl flow, and turbulent flow is simulated. The influences of dispersing hybrid nanoparticles, inlet velocity (Vin), inlet temperature (Tin), and gravity force on the Darcy factor (f), convective heat transfer coefficient (h), and thermal efficiency (n) have been investigated. When hybrid nanoparticles utilize, the efficiency (n) increases by approximately 3.25% in the presence of a turbulator. Furthermore, the addition of nanoparticles significantly enhances the efficiency gains from the turbulator, with an improvement of about 46.65%. In the absence of a turbulator, as Vinincreases, the values of n and "h" also increase by approximately 8.91% and 12.25%, respectively. When Vinis 0.06 m/s, the installation of a turbulator can increase n by about 8.54%. With the increase in Tinfor the absorber pipe equipped with a turbulator, efficiency decreases by approximately 10.86%. For a conventional pipe, including the effect of gravity significantly enhances the performance, resulting in increase of approximately 67.54% in " h " , 98.14% in " f " , and 3.73% in (n). Additionally, the effectiveness of adding a turbulator on improving the efficiency diminishes when gravity is taken into account.

This work delves into the efficiency of the disturber device on the productivity of a Concentrated PhotovoltaicThermal (CPV/T) unit. For this purpose, numerical techniques were employed to model the three-dimensional CPV/T system along with a TT (twisted tape) device. Initially, the influence of tube cross-section patterns was investigated. This involves designing three distinct tubes with plain, three-lobed, and five-lobed patterns. The simulation considers PV/T systems with various tubes, both with and without the inclusion of twisted tapes, utilizing H2O as the testing fluid. The research assesses the influence of concentration ratio through varying incident irradiations at 1, 2, and 3 suns. The investigation of the temperature over the silicon layer reveals a substantial decrease in the temperature gradient with the incorporation of a twisted tape insert. The three-lobed tube demonstrated optimal performance for the PV/T module. Consequently, an examination was conducted to assess the efficacy of utilizing Al2O3-H2O nanofluid on the productivity of the system. Using the optimal insert pattern under 3 suns has been determined to improve thermal and electrical performances by 5.1 % and 4.2 %. A thermohydraulic analysis is implemented to measure the thermal improvement brought about by various configurations. The results demonstrated that the inserts have the potential to elevate this factor above unity. Additionally, an environmental evaluation of the presented configurations includes an analysis of two key parameters: emission reduction and saved carbon credits. The findings demonstrated that employing the CPV/T system under 3 suns with the optimal design leads to a reduction of approximately 5541 kg of carbon emissions over 10 years, resulting in a savings of about $80.3 in carbon credits.

The process of cooling the photovoltaic (PV) cells is essential since increasing solar cell temperatures reduces electrical effectiveness. One suggested method to reduce cell temperature is employing PCM (phase change material) mixed with nanomaterial. Thermoelectric modules between the layers are also recommended to increase electrical efficiency. By taking advantage of machine learning predictive algorithms, the objective is to forecast the effectiveness of a PV unit equipped with finned thermal storage unit in existence of nanomaterials, while maintaining an appropriate accuracy based on two evaluation metrics throughout prediction. According to the data analytics of the simulation, the selected models used to achieve this goal are linear regression, polynomial regression, lasso regression, and an Auto -Regressive Integrated Moving Average (ARIMA) model. These models were then examined employing the root mean squared error (RMSE) and mean absolute percentage error (MAPE) across three cases, namely plain mode, mode with fins, and plain mode with the effect of gravity. The test RMSE and MAPE of these models across the above-mentioned cases were then calculated for comparison purposes, where the best-performing model for predicting both PCM temperature and melting fraction (MF) was ARIMA, with an average RMSE of 0.11, and an average MAPE of 0.0003 for predicting PCM temperature and an average RMSE of 0.003, and an average MAPE of 0.0034 for predicting MF across all cases. The ARIMA model was then used to predict the MF, PCM temperature, and PV temperature of the last case, namely mode with fins and the effect of gravity. Finally, this model was also used to predict the time at which the PCMs are completely melted in all modes, as well as to predict PV temperature. The total electrical efficiency of the mode with fins and the effect of gravity were calculated using the predicted PV temperature, yielding a result of 13.993 %.

This investigation emphases on the performance of a solar cell with a 1 m2 area, using a micro-channel heat sink as a cooling unit. The goal is to explore the optimal design of the sinusoidal geometry of the cooling heat sink to intensify output power, enhance cooling, and minimize the negative impact of heat on solar cells under high radiation, thus extending their lifespan. The study employs simulation and modeling in ANSYS FLUENT software v2021 to analyze the impact of different factors on solar cell treatment. Fourteen designs are tested, varying in the number, frequency, and wavelength of fin sine waves used in the thermal heat sinks. Furthermore, the investigation evaluates the influence of operational factors like the velocity of fluid and the intensity of applied radiation on efficiency and exergy. The outputs demonstrated that augmenting the sinusoidal fins in the cooling fluid (from 5 to 21) leads to a maximum electrical perfomance of 38.52 % for the solar cell. Expanding the sine wave's amplitude can improve efficiency from 38.41 % to 38.69 %. Similarly, decreasing the wavelength leads to efficiency gains from 38.43 % to 38.56 %. In the best-case scenario, efficiency is meaningfully improved when the flow rate is augmented from 20 to 100 g/min. The efficiency increases exponentially from 37.16 % to 38.97 %.

This article delves into the numerical examination of enhancing the productivity of a photovoltaic (PV) system in conjunction with reflectors. In bottom of the traditional PV, thermoelectric generator (TEG) has been used which made from Cu2SnS3 as a sustainable material. A spectral filter, comprising a water-MgO nanofluid, has been applied. To manage the silicon layer's temperature and ensure uniformity, a paraffin layer has been strategically placed at the system's bottom. The paraffin zone incorporates MWCNT nanoparticles mixed with RT25 for improved material properties. To augment conduction, sinusoidal fins have been affixed to the upper wall of the paraffin zone. The simulation involves an unsteady process, validated through comparisons with prior experimental and numerical works. Four distinct cases, considering the use of reflectors and fins, demonstrate their effects on key parameters. Results showcase variations in liquid fraction (LF), temperature of filter at outlet (Tout), paraffin temperature (TPCM), and electrical performance (tie) over time. As time progresses the temperatures of different layers rise, impacting tie negatively. The LF and TPCM values increase due to the growing melt phase within the domain. Notably, the impact of fins on tie diminishes by 62.79 % and 97.3 % in the presence and absence of reflectors, respectively. The integration of fins in the presence of reflectors reduces panel temperatures, improving uniformity by 3.47 %, 0.38 %, and 0.23 % at 1, 2, and 3 h, respectively. This research contributes valuable insights into optimizing PV-TEG system efficiency through the strategic use of reflectors and fins, showcasing their nuanced effects on performance and thermal management.

This research explores the combination of fins into thermosyphon solar collectors to enhance energy efficiency. The storage system includes a finned container filled with nanomaterial (a blend of Al2O3 nanoparticles and paraffin (RT30)), while the fluid circulating within the tube consists of a homogeneous mixture of copper nanoparticles and water. Unsteady laminar flow within a three-dimensional domain, incorporating gravitational forces, has been modeled. The numerical approach has undergone rigorous validation, demonstrating strong agreement with both experimental and numerical data. Effects of fin installation and nano-powder dispersion have been investigated across various scenarios. At t = 60 min, the liquid fraction (LF) is approximately 2.08 times higher in the system with fins compared to the simple case. LF progressively increases over time, reaching a value 3.1 times higher at t = 60 min compared to t = 30 min. The temperature of the nanofluid in the tank rises over time. Despite the enhanced nanofluid temperature in the tube due to fin presence, a decrease occurs within the domain due to accelerated melting rate in the container. Incorporation of nanoparticles into paraffin shows an improvement in LF by approximately 11.66 % in the presence of fins.

Concentrated photovoltaic thermal (CPVT) systems involving parabolic reflector have been scrutinized in this article. The purpose of using such a concentrated solar system is achieving higher electrical power and greater thermal productivity. The configuration of cooling system is very significant part of designing such CPVT system, and three configurations were utilized in this numerical modeling: (1) smooth duct (case I); (2) sinusoidal duct (case II); and (3) sinusoidal duct equipped with sinusoidal fins (case III). The utilized testing fluid was a mixture of water and hybrid nanoparticles, and homogeneous formulation was utilized for finding the properties of nanomaterial. Two steps for simulations have been considered: (1) finding the distribution of heat flux involving pure radiation within two-dimensional domains and (2) three-dimensional laminar flow of hybrid nanofluid involving all layers of PV. Active variables of present modeling were: concentration of hybrid additives (ϕ = 0, 0.04), amplitude (a = 1, 2 and 4 cm) and pitch ratio (λ = 0, 4 and 16 mm) of sinusoidal duct; number of fins (NoF = 1, 3); inlet flow rate (Q = 1, 2, 3 L min−1). When sinusoidal duct has been applied in the absence of helical fin, the electrical efficacy elevates about 2.5

This study discusses an evacuated tube collector-type solar water heater (ETCSWH) using a phase change material (PCM) chamber with fins, nanofluid, and nano-enhanced phase change material (NEPCM). First, the charging phenomena in a horizontal triplex tube heat exchanger (TTHX) equipped with fins, natural convection, and an ETCSWH system without PCM is simulated to validate the solution. The impact of adding fins and nanoparticles with a volume fraction of 3% of Al2O3 and Cu to paraffin wax and water-based fluid, respectively, on the unit's efficiency has been examined. The proposed system for the PCM melting process, heat storage, fluid flow behavior in the system, and velocity distribution and temperature contour in the storage tank and three parts of the absorber tube have been evaluated using ANSYS FLUENT software in a three-dimensional and transient simulation. The results show that Case 8 has improved by 39.7% compared to Case 1 and Case 4 by 5.2% compared to Case 1 within 4 h of the melting process. Also, Case 8 with a 43% and 6.4% shorter melting time than Cases 1 and 5 has the best performance and the greatest heat transfer rate. The productivity of the ETCSWH system is considerably enhanced by the use of fins, NEPCM, and nanofluid.