Concentrating solar power(CSP) has garnered considerable global attention as a reliable means of generating bulk electricity, effectively addressing the intermittent nature of solar resources.The integration of molten...Concentrating solar power(CSP) has garnered considerable global attention as a reliable means of generating bulk electricity, effectively addressing the intermittent nature of solar resources.The integration of molten salt technology for thermal energy storage(TES) has further contributed to the growth of CSP plants;however, the corrosive nature of molten salts poses challenges to the durability of container materials, necessitating innovative corrosion mitigation strategies.This review summarizes scientific advancements in high-temperature anticorrosion coatings for molten nitrate salts, highlighting the key challenges and future trends.It also explores various coating types, including metallic, ceramic, and carbon-based coatings, and compares different coating deposition methods.This review emphasizes the need for durable coatings that meet long-term performance requirements and regulatory limitations, with an emphasis on carbon-based coatings and emerging nanomaterials.A combination of multiple coatings is required to achieve desirable anticorrosion properties while addressing material compatibility and cost considerations.The overall goal is to advance the manufacturing, assembly, and performance of CSP systems for increased efficiency, reliability, and durability in various applications.展开更多
To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surfa...To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.展开更多
Thermal energy storage(TES) systems use solar energy despite its irregular availability and day-night temperature difference.Current work reports the thermal characterizations of solar salt-based phase change composit...Thermal energy storage(TES) systems use solar energy despite its irregular availability and day-night temperature difference.Current work reports the thermal characterizations of solar salt-based phase change composites in the presence of graphene nanoplatelets(GNP).Solar salt(60:40 of NaNO_(3):KNO_(3)) possessing phase transition temperature and melting enthalpy of 221.01℃ and 134.58 kJ/kg is proposed as a phase change material(PCM) for high-temperature solar-based energy storage applications.Thermal conductivity must be improved to make them suitable for widespread applications and to close the gap between the system needs where they are employed.GNP is added at weight concentrations of 0.1%,0.3%,and 0.5% with solar salt using the ball milling method to boost its thermal conductivity.Morphological studies indicated the formation of a uniform surface of GNP on solar salt.FTIR spectrum peaks identified the physical interaction between salt and GNP.Thermal characterization of the composites,such as thermal conductivity,DSC and TGA was carried out for the samples earlier and later 300 thermal cycles.0.5% of GNP has improved the thermal conductivity of salt by 129.67% and after thermal cycling,the enhancement reduced to 125.21% indicating that thermal cycling has a minor impact on thermal conductivity.Phase change temperature decreased by around 2.32% in the presence of0.5% GNP and the latent heat reduced by 4.34% after thermal cycling.TGA thermograms depicted the composites initiated the weight loss at around 550℃ after which it was rapid.After thermal cycling,the weight loss initiated at ~40℃ lower compared to pure salt,which was found to be a minor change.Thermal characterization of solar salt and GNP-based solar salt composites revealed that the composites can be used for enhanced heat transfer in high-temperature solar-based heat transfer and energy storage applications.展开更多
A new approach to application of mid-and low-temperature solar thermochemical technology was in-troduced and investigated.Concentrated solar thermal energy in the range of 150―300℃ can be effi-ciently converted into...A new approach to application of mid-and low-temperature solar thermochemical technology was in-troduced and investigated.Concentrated solar thermal energy in the range of 150―300℃ can be effi-ciently converted into high-grade solar fuel by integrating this technique with the endothermic reaction of hydrocarbons.The conversion mechanism of upgrading the low-grade solar thermal energy to high-grade chemical energy was examined based on the energy level.The new mechanism was used to integrate two novel solar thermal power systems:A solar/methanol fuel hybrid thermal power plant and a solar-hybrid combined cycle with inherent CO2 separation using chemical-looping combustion,for developing highly efficient solar energy use to generate electricity.An innovative prototype of a 5-kW solar receiver/reactor,as the key process for realizing the proposed system,was designed and manu-factured.Furthermore,experimental validation of energy conversion of the mid-and low-temperature solar thermochemical processes were conducted.In addition,a second practical and viable approach to the production of hydrogen,in combination with the novel mid-and low-temperature solar thermo-chemical process,was proposed and demonstrated experimentally in the manufactured solar re-ceiver/reactor prototype through methanol steam reforming.The results obtained here indicate that the development of mid-and low-temperature solar thermochemical technology may provide a promising and new direction to efficient utilization of low-grade solar thermal energy,and may enable step-wise approaches to cost-effective,globally scalable solar energy systems.展开更多
A unified theory of non-equilibrium radiation thermodynamics is always in search as it is meaningful for solar energy utilization.An exergy analysis of photo-thermal interaction process between the solar radiation ene...A unified theory of non-equilibrium radiation thermodynamics is always in search as it is meaningful for solar energy utilization.An exergy analysis of photo-thermal interaction process between the solar radiation energy and solar receiver is conducted in this paper.The non-equilibrium radiation thermodynamic system is described.The thermodynamic process of photo-thermal interaction between the solar radiation and solar receiver is introduced.Energy,exergy and entropy equations for the photo-thermal process are provided.Formulas for calculating the optimum receiving temperatures of the solar receiver under both non-concentration and solar concentration conditions are presented.A simple solar receiver is chosen as the calculation example to launch the exergy analysis under non-concentration condition.Furthermore,the effect analysis of solar concentration on the thermodynamic performance of the solar receiver for solar thermal utilization is carried out.The analysis results demonstrate that both the output exergy flux and efficiency of the solar receiver can be improved by increasing the solar concentration ratio during the solar thermal utilization process.The formulas and results provided in this paper may be used as a theoretical reference for the further studies of non-equilibrium radiation thermodynamic theory and solar thermal utilization.展开更多
In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A tw...In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume method.In this study,all the thermo-physical properties are variable as the function of temperature and salt concentration.Numerical results as obtained for the experimental pond have been satisfactorily compared and validated against measured data.Furthermore,the wall shading effect has been elaborated to improve the agreement between two sets of results.The temperature of the storage zone is predicted well by the model.It also can be observed that the initial concentration profile is preserved with time.The stability of the pond in time has been investigated in order to distinguish the critical zones.Finally,the application of an energy analysis gives an efficiency of about 12%for the pond.展开更多
文摘Concentrating solar power(CSP) has garnered considerable global attention as a reliable means of generating bulk electricity, effectively addressing the intermittent nature of solar resources.The integration of molten salt technology for thermal energy storage(TES) has further contributed to the growth of CSP plants;however, the corrosive nature of molten salts poses challenges to the durability of container materials, necessitating innovative corrosion mitigation strategies.This review summarizes scientific advancements in high-temperature anticorrosion coatings for molten nitrate salts, highlighting the key challenges and future trends.It also explores various coating types, including metallic, ceramic, and carbon-based coatings, and compares different coating deposition methods.This review emphasizes the need for durable coatings that meet long-term performance requirements and regulatory limitations, with an emphasis on carbon-based coatings and emerging nanomaterials.A combination of multiple coatings is required to achieve desirable anticorrosion properties while addressing material compatibility and cost considerations.The overall goal is to advance the manufacturing, assembly, and performance of CSP systems for increased efficiency, reliability, and durability in various applications.
文摘To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.
文摘Thermal energy storage(TES) systems use solar energy despite its irregular availability and day-night temperature difference.Current work reports the thermal characterizations of solar salt-based phase change composites in the presence of graphene nanoplatelets(GNP).Solar salt(60:40 of NaNO_(3):KNO_(3)) possessing phase transition temperature and melting enthalpy of 221.01℃ and 134.58 kJ/kg is proposed as a phase change material(PCM) for high-temperature solar-based energy storage applications.Thermal conductivity must be improved to make them suitable for widespread applications and to close the gap between the system needs where they are employed.GNP is added at weight concentrations of 0.1%,0.3%,and 0.5% with solar salt using the ball milling method to boost its thermal conductivity.Morphological studies indicated the formation of a uniform surface of GNP on solar salt.FTIR spectrum peaks identified the physical interaction between salt and GNP.Thermal characterization of the composites,such as thermal conductivity,DSC and TGA was carried out for the samples earlier and later 300 thermal cycles.0.5% of GNP has improved the thermal conductivity of salt by 129.67% and after thermal cycling,the enhancement reduced to 125.21% indicating that thermal cycling has a minor impact on thermal conductivity.Phase change temperature decreased by around 2.32% in the presence of0.5% GNP and the latent heat reduced by 4.34% after thermal cycling.TGA thermograms depicted the composites initiated the weight loss at around 550℃ after which it was rapid.After thermal cycling,the weight loss initiated at ~40℃ lower compared to pure salt,which was found to be a minor change.Thermal characterization of solar salt and GNP-based solar salt composites revealed that the composites can be used for enhanced heat transfer in high-temperature solar-based heat transfer and energy storage applications.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50836005, 50520140517 and 50506004)
文摘A new approach to application of mid-and low-temperature solar thermochemical technology was in-troduced and investigated.Concentrated solar thermal energy in the range of 150―300℃ can be effi-ciently converted into high-grade solar fuel by integrating this technique with the endothermic reaction of hydrocarbons.The conversion mechanism of upgrading the low-grade solar thermal energy to high-grade chemical energy was examined based on the energy level.The new mechanism was used to integrate two novel solar thermal power systems:A solar/methanol fuel hybrid thermal power plant and a solar-hybrid combined cycle with inherent CO2 separation using chemical-looping combustion,for developing highly efficient solar energy use to generate electricity.An innovative prototype of a 5-kW solar receiver/reactor,as the key process for realizing the proposed system,was designed and manu-factured.Furthermore,experimental validation of energy conversion of the mid-and low-temperature solar thermochemical processes were conducted.In addition,a second practical and viable approach to the production of hydrogen,in combination with the novel mid-and low-temperature solar thermo-chemical process,was proposed and demonstrated experimentally in the manufactured solar re-ceiver/reactor prototype through methanol steam reforming.The results obtained here indicate that the development of mid-and low-temperature solar thermochemical technology may provide a promising and new direction to efficient utilization of low-grade solar thermal energy,and may enable step-wise approaches to cost-effective,globally scalable solar energy systems.
基金This study is financially supported by the Excellent Youth Foundation of Jilin Province of China(Grant No.20190103062JH)the Special Project for the Outstanding Youth Cultivation of Jilin City of China(Grant No.20190104126).
文摘A unified theory of non-equilibrium radiation thermodynamics is always in search as it is meaningful for solar energy utilization.An exergy analysis of photo-thermal interaction process between the solar radiation energy and solar receiver is conducted in this paper.The non-equilibrium radiation thermodynamic system is described.The thermodynamic process of photo-thermal interaction between the solar radiation and solar receiver is introduced.Energy,exergy and entropy equations for the photo-thermal process are provided.Formulas for calculating the optimum receiving temperatures of the solar receiver under both non-concentration and solar concentration conditions are presented.A simple solar receiver is chosen as the calculation example to launch the exergy analysis under non-concentration condition.Furthermore,the effect analysis of solar concentration on the thermodynamic performance of the solar receiver for solar thermal utilization is carried out.The analysis results demonstrate that both the output exergy flux and efficiency of the solar receiver can be improved by increasing the solar concentration ratio during the solar thermal utilization process.The formulas and results provided in this paper may be used as a theoretical reference for the further studies of non-equilibrium radiation thermodynamic theory and solar thermal utilization.
文摘In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume method.In this study,all the thermo-physical properties are variable as the function of temperature and salt concentration.Numerical results as obtained for the experimental pond have been satisfactorily compared and validated against measured data.Furthermore,the wall shading effect has been elaborated to improve the agreement between two sets of results.The temperature of the storage zone is predicted well by the model.It also can be observed that the initial concentration profile is preserved with time.The stability of the pond in time has been investigated in order to distinguish the critical zones.Finally,the application of an energy analysis gives an efficiency of about 12%for the pond.
