We put forward a novel linear solar concentrator featuring an asymmetric parabolic reflector and an independently movable receiver, and conducts an initial exploration into the feasibility of this new concentrator across different seasons and geographical regions worldwide. On this basis, this study systematically examines the effects of various deviations on the optical performance of fixed-reflector parabolic concentrators. Based on ray-tracing simulations, a comprehensive analytical method for evaluating deviation effects was developed. This method quantifies the influence of key parameters-including reflector angle and surface profile deviations, tracker angle deviations, receiver position deviations, and concentrator orientation deviations-on the geometric optical efficiency. This methodology was applied to analyze two representative design cases, employing contour maps to illustrate optical efficiency variations under different deviation conditions and defining permissible deviation ranges corresponding to various efficiency thresholds. Building upon this, recommended control metrics for various deviations are proposed, alongside optimization strategies-such as adjusting the receiver position or modifying the tracking model-to enhance the system's tolerance capability. Findings indicate that the recommended deviation control metrics for this concentrator are lower than the existing standards for linear concentrators, and as the aspect ratio of the concentrator decreases, its tolerance capability improves, while the peak efficiency decreases. This study provides data references for the design, application, and optimization of fixed-reflector parabolic concentrators and also offers a reference for the analysis of other solar concentrating methods and optical engineering.
The worldwide requirement for the most efficient and sustainable solar energy solutions has driven the development of bifacial and tandem photovoltaic (PV) technologies. The adoption of bifacial perovskite-silicon (PVK-Si) tandem solar cells has provided a new way to improve solar energy conversion efficiency. This work provides a comprehensive analysis of the energy yield potential of east-west (E/W) and north-south (N/S) oriented bifacial perovskite-silicon tandem solar panels in both single-axis tracking and fixed-tilt configurations. We focus on heterojunction with intrinsic thin layer (HIT), two-terminal tandem (2TT), and three-terminal tandem (3TT) configurations to evaluate their performance under varying ground albedo conditions. A simulation model based on matlab computes the annual and seasonal energy yields for these configurations. The results show that tracking panels consistently outperform their fixed-tilt counterparts. Seasonal analysis also demonstrates that E/W-oriented tracking panels perform exceptionally well in summer, whereas N/S-oriented tracking panels maintain a relatively stable output in both summer and fall. The optimized panel orientation significantly mitigates the skewed power output peaks observed in conventional configurations by strategically adjusting subcell exposure to incident sunlight. This approach results in a more balanced energy distribution throughout the day. These findings highlight the advantages of tracking bifacial tandem photovoltaic systems over conventional fixed-tilt installations, particularly for sites that require consistent power output and higher energy yields.
To enhance the conversion efficiency of solar energy in rural buildings, a solar energy comprehensive utilization system is proposed for rural buildings, which mainly consists of three subsystems: solar concentrated photovoltaic/photothermal subsystem, energy supply and heat storage subsystem, and photovoltaic/photothermal utilization subsystem. A system simulation model is developed in trnsys to evaluate the system's performance under various operating conditions. The key components in this system are validated, and the errors indicate that the model can be used as a system simulation. Furthermore, the effects of outlet temperature and fluid flowrate of the heat collector, heat supply tank outlet temperature, load ratio, etc., on the system performance are studied, and the optimal flowrate, components outlet temperatures, and load ratio are obtained for this system. The control strategy is proposed and used in the simulation based on the optimal parameters, and then the energy consumption structure is investigated. Simulation results reveal that during the cooling season, solar thermal energy contributes 81.8% of the total energy consumption, while the contributions from natural gas and photovoltaic electricity are 1.7% and 16.5%, respectively. These findings confirm the technical feasibility and high solar energy utilization of the proposed system, highlighting its potential as an efficient and sustainable energy solution for rural building applications.
To improve the comprehensive performance of the solar photovoltaic-thermal (PV/T) integrated system and address the issue of reduced conversion efficiency caused by increased PV temperature, this study establishes a three-dimensional transient model of a PV/T-phase change material (PCM) system with bionic fractal fins. Paraffin RT-42 (phase change temperature: 311-316 K) is selected as the PCM, and computational fluid dynamics (CFD) is employed to systematically investigate the effects of the presence or absence of PCM, fin structure, solar radiation intensity, and cooling water flowrate on system performance. The results show that the integration of PV/T and PCM significantly enhances the temperature uniformity of the PV, reducing the maximum temperature difference from 6 degrees C to 4 degrees C. Compared with the PV/T system, the thermal efficiency is improved by 24.82% and the electrical efficiency by approximately 5%. The bionic fractal fins outperform traditional straight fins in heat transfer enhancement by increasing the heat exchange area and constructing a multipath heat transfer network. When the solar radiation intensity increases from 600 W/m2 to 1000 W/m(2), the system's thermal efficiency rises from 54.96% to 80.36%, while the electrical efficiency decreases from 14.38% to 13.39% due to PV temperature increase. The cooling water flowrate has a significant effect on system temperature regulation: at a flowrate of 0.1 m/s, the average PV temperature is 9.22 K lower than that at 0.01 m/s, and the electrical efficiency is improved by 5.2%. Thus, optimizing the thermal and electrical efficiency of the system can be achieved by adjusting the flowrate. This research provides a new technical path and theoretical support for improving the performance of PV/T systems.
Over the last decade, there has been significant interest in renewable energy resources, with solar energy emerging as one of the most promising options. Among various technologies, the parabolic trough solar reflector with innovative receivers plays a crucial role in efficient solar power harvesting. This experimental study focuses on a stationary parabolic trough with a 2.8 m(2) aperture area, integrated with a manually operated dual-axis sun-tracking system. The primary objective was to evaluate and enhance the system's thermal performance over three representative days in February, under both sunny and cloudy conditions. To optimize optical performance while minimizing design and fabrication costs, the prototype incorporated mirror strips, which also helped reduce lift and drag forces caused by high air pressure around the trough. A three-day experiment was conducted to assess the system's performance, and the results demonstrated that the water's highest recorded temperature was 84.2 degrees C, while the regenerative air attained 75.1 degrees C using a novel helical-coiled receiver design. With a maximum receiver thermal efficiency of 85.4% and an overall system efficiency of 55.4%, the design exhibits considerable promise for integrated air and water heating applications in residential and industrial contexts.
Solar desalination is a promising method to utilize renewable energy for producing freshwater. This is done by utilizing a solar still to evaporate and condense impure water into potable water. However, traditional solar stills are less efficient. This study proposes a modified solar still design that incorporates cooling fans over the south-facing plexiglass, which are powered by a solar-charged battery, forming a fully standalone system. A rainwater collection tray is also integrated for its use during rainy days. The section of the tray facing south also acts as a booster mirror during bright sunlight. The system achieved a peak water temperature of 60 degrees C, with a yield of 0.95 kg/m(2) h on October 12, 2024. Operating the cooling fans at their maximum duty cycle reduced the temperature of the south-facing plexiglass by approximately 10%, improving the condensation rate. The rainwater collection tray gathered 18.6 L on September 10, 2024, and 17.3 L on October 17, 2024. Under sunny conditions, the system recorded peak energy and exergy efficiencies of 34% and 3.38%, respectively. These dropped significantly during rainy days to an average of 8.14% and 0.27%, respectively. The fractional exergy of evaporation peaked at 0.69 on warmer days and fell to 0.6 on cooler days. Conversely, convection exergy declined from 0.125 to 0.07 as temperature increased. After desalination, water quality parameters improved, aligning with the findings of the existing literature on solar-distilled water.
Agri-photovoltaics (Agri-PV) represents a dual land-use strategy integrating solar energy production with agriculture to tackle global challenges in energy, water, and food security. This study develops a generalizable framework for optimizing Agri-PV systems across diverse climates, demonstrated via case studies in four South Asian cities representing key archetypes: humid subtropical plains (Lahore), arid coastal environments (Karachi), high-altitude cold regions (Gilgit), and desert climates (Umerkot). Using regression-calibrated irradiance data from pvsyst, pvgis, and pvlib, we evaluated energy yield, photosynthetically active radiation (PAR) availability, and techno-economic performance for tilted and vertical bifacial PV configurations. Experiments show tilted systems are beneficial than vertical designs with yearly energy production 95-104% higher and winter production up to 70%. The effects of snow-albedo in Gilgit increased winter production by 16-55%. The ideal 7 m distance between rows optimized energy generation, mechanized agriculture and crop stability and crop integration lowering the levelized cost of electricity (LCOE) by 10-58 to reach 0.014-0.052 USD/kWh site-dependently. This new framework presents the initial beam/diffuse PAR analysis of breakdown on the basis of the South Asian climate, and it presents globally relevant principles of climate-specific Agri-PV implementation to maximize the sustainability and cost-effectiveness. These results demonstrate that properly designed Agri-PV systems can be used to increase the rates of renewable energy and sustainable agriculture, as well as advance financial sustainability in a wide range of settings.
Efficient cooling is crucial to avert the 30-50% postharvest losses of agricultural products in warm climates when temperature control fails, preserving food quality and the integrity of the supply chain. The need for energy to cool buildings is rising globally, especially in hot countries. Most of this increase is to meet medium- and large-scale refrigeration demands to keep agricultural produce fresh. A novel solar cooling system to meet such demand is highly desirable to help meet the increased demand for energy, reduce CO2 emissions, and cut electricity costs, especially in hot and arid areas. This research proposes a thermal solar cooling system to meet refrigeration demand. The proposed system was investigated for a hot and arid environment using trnsys 18 software. The main system variables, such as thermal solar collector area, collector slope angle, and storage capacity, were explored regarding solar fraction, coefficient of performance, and primary energy saving. The results demonstrate that a solar cooling system to cool a warehouse of 144-m(2) area used to store 112 tons of fruits and vegetables at 6-8 degrees C requires an evacuated tube solar collector of area 1173 m(2) supplied by TVP SOLAR with a claimed solar to thermal efficiency of 72%. Also, the solar panel gradient to achieve the highest values of solar fraction was 30 deg, with 60 m(3) storage capacity and collector pump flowrate of 20.8 kg/s with a backup system (boiler 100 kWh capacity), to achieve the highest values of solar fraction, coefficient of performance of the whole system, coefficient of performance (COP) of absorption chiller, and primary energy saving 0.53, 0.24, 0.68, and 0.24, respectively. However, financial analysis showed that the investment cost of the proposed system is 45% higher than that of the traditional system, the vapor compressor chiller system, in terms of pound/Wh. However, the solar thermal cooling system's ongoing (running) cost was 60% cheaper than a vapor compressor cooling system. Moreover, the investment payback period was nearly 10 years. Finally, CO2 emissions would be reduced by nearly 35% per annum by utilizing the proposed system compared to a vapor chiller compressor system.
A hybrid drying system uses both a steam dryer and a flue gas dryer to reduce fuel moisture content, which results in increasing the energy efficiency of the biomass power plant. It has been demonstrated previously that flash steam from a blowdown heat recovery system may be used to operate a hybrid drying system. Steam is supplied to the steam dryer from direct steam-generating parabolic trough collectors. However, the intermittent nature of solar radiation means that the steam dryer will have to operate inefficiently with a variable steam supply. In this article, it is proposed that direct steam-generating parabolic trough collectors should be integrated with a blowdown heat recovery system. The problem of the fluctuating solar radiation is solved by varying the blowdown rate so that the steam dryer receives a steady steam supply. Blowdown rate is maximum when there is no solar energy, and blowdown rate is minimum when the maximum amount of steam is generated by parabolic trough collectors. The daily operation of the proposed system is divided into two modes depending on the availability of solar energy. It is demonstrated that the proposed system can reduce fuel consumption by 1.70% annually compared with the reference system that supplies steam to a steam dryer using only a blowdown heat recovery system.
Accurate assessment of solar resources is critical for photovoltaic (PV) project feasibility and energy auctions, yet satellite-based estimates can differ significantly from ground measurements, creating uncertainty and motivating the need for reliable site adaptation methods. Within this context, the present article proposes a method for enhancing the linear regression site adaptation method by incorporating solar irradiance band separation, clear-sky classification index (Kc) analysis, and machine learning algorithms (artificial neural network (ANN)) while also evaluating the influence of irradiance data collection period and diverse climatic conditions validation. Results show that relative root mean square error (rRMSE) improvements were site dependent: all methods improved rRMSE at sites with over 75% clear-sky days, while only ANN was effective at 50% clear-sky sites. For Florian & oacute;polis (Brazil), single-year analyses showed that the irradiance band method achieved the lowest relative mean bias error (rMBE) in 50% of cases, compared to 33% for linear regression and 17% for ANN. The findings suggest that the proposed solar irradiance band classification is particularly well-suited for regions with stable and abundant solar resources. Additionally, results indicate that using two years of measured data would offer significant improvements over a one-year period and could reduce uncertainties for long-term PV plant performance assessment and aid implementation by industry planners and researchers in both government and nongovernment organizations.
This study investigates the enhancement of thermal and exergy performance in a solar air heater using activated carbon nanoparticle (ACNP) coatings integrated with peanut-shell-based composite absorber plates. Experimental and optimization analyses were conducted to determine the influence of mass flow-rate, ACNP concentration, and solar intensity on system efficiency. Results revealed that the incorporation of bio-based peanut-shell composites and ACNP coatings significantly improved heat absorption and transfer characteristics. The optimum operating conditions were identified at a mass flow-rate of 0.035 kg/s, ACNP concentration of 20 wt%, and solar intensity of 760 W/m(2), achieving a maximum thermal efficiency of 78.5%, exergy efficiency of 4.08%, and outlet air temperature of 78.2 degrees C, with a moderate pressure drop of 180 Pa. Validation through response surface methodology (RSM) confirmed strong agreement between predicted and experimental results, emphasizing the accuracy of the developed models. The contour and 3D surface plots demonstrated clear interaction effects between parameters, optimizing system performance effectively. The findings highlight that ACNP-coated peanut-shell composites provide a sustainable, cost-effective, and high-performance solution for solar air-heating applications, promoting the advancement of bio-inspired materials in renewable thermal energy systems.
To address global water scarcity and promote sustainable freshwater solutions, a novel solar distillation system has been developed and numerically analyzed. Three cases namely (a) conical solar still (CSS) consisting of partially covered photovoltaic thermal (PVT) flat plate collectors (FPCs), (b) CSS with fully covered PVT-FPCs, and (c) CSS containing FPCs have been considered. Detailed thermal models for different cases have been developed, and the results are compared. An experimental validation of case (a) has been presented. The root mean square percentage deviation for water temperature, condensing cover temperature, and yield is obtained as 5.30%, 4.90%, and 9.11%, respectively. The conical geometry of the proposed system increases the condensing surface area and reduces the shading effect, improving distillation performance. Results show that the maximum collector outlet and basin water temperatures reached approximately 99.8 degrees C and 95.2 degrees C, respectively, at the mass flow rate of 0.04 kg/s and N = 8. Among the configurations, case (c) demonstrated the best performance, achieving a daily distillate yield of 6.44 kg and a maximum instantaneous efficiency of 88.28%. However, case (c) is not self-sustainable. In comparison, cases (a) and (b) recorded yields of 4.70 kg and 3.33 kg and maximum instantaneous efficiency of 79.76% and 25.32%, respectively. The suitability of cases (a) and (b) depends on the requirements of users. Case (a) is suitable when comparatively low electrical output and high yield are required, whereas case (b) is suitable when high electrical output and low yield are required.
This study investigates a novel solar-driven triple-generation Kalina cycle designed to supply electricity, cooling, and heating under Kabul's climatic conditions. The problem addressed is the lack of a comprehensive thermodynamic, economic, and environmental evaluation for such multi-generation systems, particularly when solar storage plays a dominant role in the system performance. To fill this gap, the research conducts-for the first time-a fully integrated conventional and advanced exergy, exergoeconomic, and exergoenvironmental analysis of a solar-assisted triple-generation Kalina cycle. A detailed thermodynamic model was developed in ees to simulate summer and winter conditions. The advanced exergy results show that the solar thermal tank in summer and the auxiliary boiler in winter are the major sources of irreversibility; however, a substantial portion of these destructions is avoidable and exogenous (e.g., 4553 kW in summer), indicating that system-wide optimization, rather than isolated component improvements, offers the highest potential for performance enhancement. Exergoeconomic results reveal that destruction costs associated with the thermal tank (1698.8 USD/h in summer) and solar-storage investment (3077 USD/h in summer) and solar-storage investment (3077 USD/h) are the dominant contributors to total cost, implying that improved storage design is essential for long-term economic feasibility. From an environmental standpoint, the auxiliary boiler generates the highest impacts (up to 302.8 Pts/h), suggesting that low-emission fuel alternatives or boiler-side enhancements are critical. Overall, the system demonstrates strong potential for sustainable and cost-effective energy supply, meaning that improvements targeting avoidable and exogenous losses-especially within the storage and boiler subsystems-can significantly increase efficiency while reducing economic and environmental burdens.
This work presents the first comprehensive analytical solution for packed-bed thermocline storage systems that fully accounts for peripheral heat losses, offering a novel transient solution for local thermal non-equilibrium conditions and the first exact solution for the limiting case of local thermal equilibrium. Starting from a set of transient partial differential energy equations in cylindrical coordinates for the fluid and solid phases, the model was derived by integrating over the cross section. The solution identifies six key dimensionless parameters that govern the system performance. The model's accuracy was validated against experimental data, demonstrating excellent agreement and successfully capturing the characteristic temperature drop near the tank outlet. Crucially, this analysis is valid for any combination of heat transfer fluid and solid filler. The resulting analytical framework provides not only a valuable tool for efficient system design but also a reliable benchmark for validating complex numerical models.
The electrical performance and longevity of photovoltaic (PV) modules are critically affected by module temperature. The final operating temperature of a PV module under load is determined by the balance between the cooling effect of drawing electrical power and the heating effect of Joule losses in internal resistance. Simple energy balance models predict that cooling is dominant, and thus, module temperature should decrease as electrical efficiency increases. This study aims to experimentally determine the net thermal result from these opposing effects and demonstrate the role of Joule heating. Two identical PV modules were examined-one under load and another in open circuit-under clear/sunny and cloudy conditions. The findings showed that the surface temperature of the loaded module was systematically higher in both conditions. This temperature difference, averaging up to 0.9 (maximum 1.9) on a clear/sunny day and 0.5 (maximum 1.7) on a cloudy day, proves the dominance of Joule heating in internal resistance as an intrinsic heat source, rather than the cooling effect of drawing electrical power. This result reveals an inconsistency between simple energy balance models and experimental observations, emphasizing Joule heating's role in PV module thermal behavior. The findings offer important implications for improving thermal models, performance predictions, and system lifespan, especially for new high-power-density PV modules.
This study presents a numerical analysis of an indirect-expansion water-to-air heat pump (HP) combined in series with linear concentrating photovoltaic thermal collectors (CPVT), to meet the space heating demand of a residential house during the cold season, while maximizing the solar contribution. The system is dynamically simulated in TRNSYS under real climatic conditions in Constantine, Algeria, based on the actual thermal load of a modeled house. The CPVT collector field and the thermal storage volume are sized to optimize solar coverage and limit thermal losses. The results show an optimal thermal efficiency of the collectors throughout the heating season, with an average of 47% during sunlit hours. However, the concentration of solar radiation affects the electrical efficiency, which averages 6.29% during these hours. The CPVT collectors supply 58% of the heat pump's thermal demand, with coverage ranging from 34% to 83%, while the heat pump meets 93% of the total heating demand with an average coefficient of performance of 4.88, demonstrating the relevance of the CPVT-HP system. A sensitivity analysis indicates that thermal efficiency increases with ambient temperature, whereas electrical efficiency slightly decreases with higher irradiation. The economic analysis, conducted under two operating scenarios, reveals that in the most favorable scenario, energy savings reach 8000 USD with an estimated payback period of 9 years, confirming the system's profitability when operated year-round. Overall, the results highlight the technical, economic, and environmental viability of this CPVT-HP coupling, particularly in regions with high solar potential.
Photovoltaic (PV) systems are widely used in desert areas. Hence, the damage due to extreme wind conditions and the power loss due to sand accretion (i.e., soiling) are the major difficulties facing such energy systems. In this work, the windbreak is introduced as a passive cost-effective applicable solution to avoid or mitigate the aforementioned problems. A detailed numerical study followed by a techno-economic assessment is performed to evaluate the effect of the windbreak on the performance of an existing PV system in a harsh desert environment in terms of structural safety, sand accretion rate, energy output of the PV system, and financial feasibility of using the windbreak. Numerical calculations showed that windbreaks reduce wind loads by almost 100% in a distance up to 10H from the windbreak (where H represents the windbreak height), and it can still be effective up to a distance of 70H. In addition, the windbreak is effective in reducing soiling, for a typical range of sand particle diameters, at distances 3H-10H. As velocity increases, the windbreak becomes more effective in reducing soiling for larger distances. The sand accretion rate reduces with the increasing windbreak height and with the reducing windbreak porosity. Favorably, using windbreaks increases the PV energy yield by 1.6% annually due to the reduction of panel soiling losses. Finally, retrofitting an existing PV plant with a windbreak was not only a safeguard solution but also found to be an economically attractive project with a reasonable return on investment.
This article presents the development and demonstration of an optimization framework for the design of a megawatt scale central solar thermal receiver composed of multiple unit cells containing arrays of micro-pins. The framework tailors the pin geometry in each unit cell across the receiver surface in response to the design incident flux. The framework is demonstrated by designing a megawatt scale thermal central receiver for heating supercritical carbon dioxide from 500 degrees C to 720 degrees C while maintaining the maximum surface temperature below 800 degrees C to ensure long-term structural integrity and creep life. Key findings reveal that the optimized receiver design significantly outperforms a uniform geometry baseline. The summer-optimized configuration achieves a 14.2% higher outlet temperature (761 degrees C versus 666 degrees C) and a 2% point gain in thermal efficiency (93% versus 91%), all while maintaining structural and hydraulic constraints. The approach can be modified for different working fluids, operational conditions, material constraints, and applications. This work provides a scalable and practical pathway for developing designs of high efficiency, additively manufactured solar receivers that can adapt to real-world solar flux variability for producing power and process heat.
In this article, turbulent forced convection heat transfer in different geometries of solar air heaters (SAHs) where turbulators are set at different angles is investigated for best thermal performance. Six turbulator arrangements are examined (labeled G1-G6), and a comprehensive analysis is presented. Each configuration is equipped with 32 discrete, rotatable turbulators, along with various surface modifications designed to enhance heat transfer. The model developed is validated using experimental, numerical, and correlation data from the published literature. The performance is measured in terms of the Reynolds number (3000 <= Re-Dh <= 13, 000), solar irradiance (200 <= I-center dot <= 1000), and the turbulator angle (0 deg <= alpha <= 45 deg). The model developed can predict several key thermal and flow parameters, including the average absorber temperature (T-a), absorber temperature contours, local air temperature (T-l), magnitude of the resultant air velocity (U), pressure drop (Delta P), average Nusselt number (Nu(Dh)), and the performance enhancement coefficient (PEC). The model outcomes reveal that the turbulator angle exerts a noticeable influence on the heat transfer rate. Both the Reynolds number and turbulator angles are found to positively correlate with the average Nusselt number (Nu(Dh)), indicating enhanced heat transfer by convection at higher flowrates and larger turbulator angles. This is especially true for the G1 and G3 configurations due to enhanced flow disturbance and the more effective mixing associated with these two configurations. Additionally, increasing solar irradiance is observed to slightly reduce the Nusselt number. This is the case primarily due to the elevated initial surface temperature, which reduces the temperature difference between the heated surface and the airflow. Analysis of the PEC further confirms that G1 consistently outperforms the other configurations, achieving PEC values up to 2 at alpha =45 deg and high Reynolds numbers. Despite a general decrease in the PEC at moderate Reynolds numbers, the PEC increases again at higher flowrates due to the fact that the increase in thermal gains outpaces the increase in the frictional pressure drop. Overall, the findings highlight the critical role of turbulator geometry and angles. The developed correlations are derived to calculate the average Nusselt number, the average pressure drop, and the performance enhancement coefficient for various configurations, turbulator angles, and their effects on airflow within a SAH in various turbulator settings.
This study proposes a combined thermal cycle by a Helium Brayton cycle at high temperatures (800-850 degrees C) on top of a water Rankine cycle. Thanks to its high thermal conductivity, helium is also an excellent heat transfer fluid, so that jet impingement heat transfer and enhancement can obtain high energy efficiency at solar receivers. NaCl is considered a phase change material (PCM) to meet the requirement of thermal storage, due to its suitable melting point of 801 degrees C, cost-effectiveness, and great reserves in nature. The studies focus on thermodynamic analysis of the power systems to obtain maximum energy conversion efficiency through optimizing system combinations and parameters of the power cycles. The studied systems with combined power cycles include: (1) simple Brayton and simple Rankine (SBSR) cycles, (2) reheated Brayton and simple Rankine cycles (RBSR), (3) reheated Brayton and reheated Rankine cycles (RBRR), (4) reheated Brayton and reheated Rankine cycle with precooling in front of gas compressor (RBRR + P), and (5) reheated Brayton and reheated Rankine cycles with recuperation in Brayton cycle (RBRR + RE). The results demonstrate that the combined system of the helium Brayton cycle and water Rankine cycle can attain a thermal efficiency in the range of 42% to 50% when the supplied helium gas temperature and pressure approach 800 degrees C and 8 MPa, respectively.
