Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was establishe...Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.展开更多
The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper publi...The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper published in Journal of Power and Energy Engineering Vol.3 No.4, April 2015, has been removed from this site.展开更多
A general solution of sun tracking for an arbitrarily oriented heliostat towards an arbitrarily located target on the earth is published. With the most general form of solar tracking formulae, it is seen that the used...A general solution of sun tracking for an arbitrarily oriented heliostat towards an arbitrarily located target on the earth is published. With the most general form of solar tracking formulae, it is seen that the used azimuthelevation, spinning-elevation tracking formulae etc. are the special cases of it. The possibilities of utilizing the general solution and its significance in solar energy engineering are discussed.展开更多
Solar energy is also a major renewable energy source that is clean and can be sustained at a minimum cost. CSP systems are another highly developed solar energy system that is environmentally friendly and can be insta...Solar energy is also a major renewable energy source that is clean and can be sustained at a minimum cost. CSP systems are another highly developed solar energy system that is environmentally friendly and can be installed with simple technology and rational cost. PV solar panels generate electric power when sunlight exists. Similarly, CSP system also generates electric power for immediate consumption when there is sunlight, but it also stores some of the solar energy as heat to be able to continue generating electric power when the weather is cloudy or during the night. In this study, an algorithm and software for effective heliostat were developed. Six districts were selected in Adana province to design and calculate solar power received by heliostat mirrors and delivered to the heat exchanger on top of the tower. Because a solar tracking mechanism is necessary for correct and instant orientation of mirrors, the developed software can calculate the orientation angles of each mirror at any moment of a day of the year. The algorithm also calculates the power received by PV solar panels with fixed orientation and with the same surface area as those of mirrors to compare the energy yields.展开更多
Solar power tower systems demand robust heliostat aiming strategies to maximize energy collection efficiency while ensuring system reliability and cost-effectiveness.This review comprehensively discusses a novel class...Solar power tower systems demand robust heliostat aiming strategies to maximize energy collection efficiency while ensuring system reliability and cost-effectiveness.This review comprehensively discusses a novel classification framework that systematically integrates heliostat field focusing systems,tracking mechanisms,and adaptive control strategies.Recent advancements in optical modeling and error detection methodologies are reported,where hybrid approaches combining analytical solutions with ray tracing have improved computational efficiency by up to 60%.The integration of machine learning with traditional control methods has enhanced tracking accuracy by 35%,while advanced multiobjective optimization frameworks have achieved 12%–15%improvement in annual energy collection under safe operating conditions.The critical challenges in computational efficiency,environmental adaptation,and system integration are identified to provide directions for future research.This analysis offers valuable insights for advancing heliostat control technologies in large-scale solar thermal applications.展开更多
Building Integrated Concentrating Solar Power (BI-CSP) schematic studies with small scale exterior two-axis tracking heliostats anchored on and semi-shading long span hanging roofs with elevated receiver(s) are presen...Building Integrated Concentrating Solar Power (BI-CSP) schematic studies with small scale exterior two-axis tracking heliostats anchored on and semi-shading long span hanging roofs with elevated receiver(s) are presented for populated urban and rural locations. Hanging roofs (inverted shallow dome shape) with two-way structural cables and mostly square infill prefabricated slabs/panels supported from a perimeter horizontal circular donut shape rim-girder-platform without a center tension ring studies are for comparing to radial cable structural configurations with a center tension ring. Cable gap grouting between slabs/panels form a pre-tensioned inverted shell structure after temporary weights are removed. Securing vertical heliostat posts studies include: three vertical bolts cast in grout gap two-way cables intersections for three point adjustment of horizontal post base plates;and one-axis adjustable manufactured post brackets bolted to sloped roof surfaces at holes cast in the gaps/slabs. A main case study schematic is around a 30m/100ft diameter hanging roof with a 0.07 sag/diameter ratio with around 271 1m2 heliostats for 230kWt solar thermal steam or air to around 300degC/572degF building integrated thermal energy storage (molten salt, firebricks, etc.) and applications (water purification, cooling, industrial process heat, etc.). A BI-CSP hanging roofs R&D project proposal is outlined: with a circular roof study diameter range of around 25m/82ft-200m/656ft diameter for comparing two-way and radial cable structural configurations for distributed steam stations and a wide range of application temperatures.展开更多
The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of hel...The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of heliostats used in the system as a function of the DNI(direct normal irradiation)was studied.The efficiencies of ORC and receiver,the power of turbine,pump,evaporator and receiver as a function of thermodynamic parameters such as temperature,pressure at the level of different components of the system are studied.The results obtained show that the number of heliostats used decreases when the DNI increases.For a DNI of 700 W/m^(2) to 500 W/m^(2),the number of heliostats goes from 280 to 60.ORC efficiency and turbine power increase respectively from 11%to 22%and from 20 kW to 50 kW when the condenser temperature decreases.Also it is noted an increase of receiver efficiency when evaporator temperature increases.展开更多
针对定日镜风致振动会降低光热电站发电效率的问题,开发一款基于深度强化学习的控制算法抑制定日镜振动。首先构建吸振器-定日镜动力学模型的Open AI Gym训练环境,完成模拟状态下深度强化学习模型的训练并验证随机振动控制效果。其次搭...针对定日镜风致振动会降低光热电站发电效率的问题,开发一款基于深度强化学习的控制算法抑制定日镜振动。首先构建吸振器-定日镜动力学模型的Open AI Gym训练环境,完成模拟状态下深度强化学习模型的训练并验证随机振动控制效果。其次搭建实验系统,通过构建包含定日镜振动特征、控制信号、奖励值与终止状态的数据集,训练智能体学习吸振器的电-磁-刚度机理。最后编写模型调用脚本,在LabVIEW主系统调用函数节点完成混合编程。结果显示在12.3 Hz的外界激励下,该算法可在1 s内计算出最优的控制信号,将±0.42 m/s^(2)的振幅降低到±0.29 m/s^(2)。该算法利用神经网络实现定日镜振动的跟踪控制,对强化学习算法落地及定日镜结构保护有一定参考意义。展开更多
基金Project(CYB14010)supported by Chongqing Graduate Student Research Innovation Project,ChinaProject(51405209)supported by the National Natural Science Foundation of China
文摘Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.
文摘The following article has been retracted due to the fact that it cannot be accepted as Duplicate Publication. The Editorial Board takes a very strong respect to the author’s situation on this matter. This paper published in Journal of Power and Energy Engineering Vol.3 No.4, April 2015, has been removed from this site.
文摘A general solution of sun tracking for an arbitrarily oriented heliostat towards an arbitrarily located target on the earth is published. With the most general form of solar tracking formulae, it is seen that the used azimuthelevation, spinning-elevation tracking formulae etc. are the special cases of it. The possibilities of utilizing the general solution and its significance in solar energy engineering are discussed.
文摘Solar energy is also a major renewable energy source that is clean and can be sustained at a minimum cost. CSP systems are another highly developed solar energy system that is environmentally friendly and can be installed with simple technology and rational cost. PV solar panels generate electric power when sunlight exists. Similarly, CSP system also generates electric power for immediate consumption when there is sunlight, but it also stores some of the solar energy as heat to be able to continue generating electric power when the weather is cloudy or during the night. In this study, an algorithm and software for effective heliostat were developed. Six districts were selected in Adana province to design and calculate solar power received by heliostat mirrors and delivered to the heat exchanger on top of the tower. Because a solar tracking mechanism is necessary for correct and instant orientation of mirrors, the developed software can calculate the orientation angles of each mirror at any moment of a day of the year. The algorithm also calculates the power received by PV solar panels with fixed orientation and with the same surface area as those of mirrors to compare the energy yields.
基金supported by the 2024 Liaoning Revitalization Talents Program(grant no.XLYC2403007).
文摘Solar power tower systems demand robust heliostat aiming strategies to maximize energy collection efficiency while ensuring system reliability and cost-effectiveness.This review comprehensively discusses a novel classification framework that systematically integrates heliostat field focusing systems,tracking mechanisms,and adaptive control strategies.Recent advancements in optical modeling and error detection methodologies are reported,where hybrid approaches combining analytical solutions with ray tracing have improved computational efficiency by up to 60%.The integration of machine learning with traditional control methods has enhanced tracking accuracy by 35%,while advanced multiobjective optimization frameworks have achieved 12%–15%improvement in annual energy collection under safe operating conditions.The critical challenges in computational efficiency,environmental adaptation,and system integration are identified to provide directions for future research.This analysis offers valuable insights for advancing heliostat control technologies in large-scale solar thermal applications.
文摘Building Integrated Concentrating Solar Power (BI-CSP) schematic studies with small scale exterior two-axis tracking heliostats anchored on and semi-shading long span hanging roofs with elevated receiver(s) are presented for populated urban and rural locations. Hanging roofs (inverted shallow dome shape) with two-way structural cables and mostly square infill prefabricated slabs/panels supported from a perimeter horizontal circular donut shape rim-girder-platform without a center tension ring studies are for comparing to radial cable structural configurations with a center tension ring. Cable gap grouting between slabs/panels form a pre-tensioned inverted shell structure after temporary weights are removed. Securing vertical heliostat posts studies include: three vertical bolts cast in grout gap two-way cables intersections for three point adjustment of horizontal post base plates;and one-axis adjustable manufactured post brackets bolted to sloped roof surfaces at holes cast in the gaps/slabs. A main case study schematic is around a 30m/100ft diameter hanging roof with a 0.07 sag/diameter ratio with around 271 1m2 heliostats for 230kWt solar thermal steam or air to around 300degC/572degF building integrated thermal energy storage (molten salt, firebricks, etc.) and applications (water purification, cooling, industrial process heat, etc.). A BI-CSP hanging roofs R&D project proposal is outlined: with a circular roof study diameter range of around 25m/82ft-200m/656ft diameter for comparing two-way and radial cable structural configurations for distributed steam stations and a wide range of application temperatures.
文摘The objective of this study is to establish a thermodynamic model of an ORC(organic Rankine cycle)for power electricity.A case study was proposed in an area where direct solar irradiation is abundant.The number of heliostats used in the system as a function of the DNI(direct normal irradiation)was studied.The efficiencies of ORC and receiver,the power of turbine,pump,evaporator and receiver as a function of thermodynamic parameters such as temperature,pressure at the level of different components of the system are studied.The results obtained show that the number of heliostats used decreases when the DNI increases.For a DNI of 700 W/m^(2) to 500 W/m^(2),the number of heliostats goes from 280 to 60.ORC efficiency and turbine power increase respectively from 11%to 22%and from 20 kW to 50 kW when the condenser temperature decreases.Also it is noted an increase of receiver efficiency when evaporator temperature increases.
