The Experts below are selected from a list of 1200 Experts worldwide ranked by ideXlab platform

Yaling He - One of the best experts on this subject based on the ideXlab platform.

  • A study of new method and comprehensive evaluation on the improved performance of Solar Power Tower plant with the CO2-based mixture cycles
    Applied Energy, 2019
    Co-Authors: Ming-jia Li, Yaling He, Jinliang Xu
    Abstract:

    Abstract This study provides an exploration on improving the performance of Solar Power Tower (SPT) plant via integrating with the CO2-based mixture Brayton cycle, and proposes a comprehensive comparison method. The effects of the crucial parameters on the SPT system are firstly revealed. Then, a comprehensive evaluation method is proposed based on 3 performance metrics including exergy efficiency, specific work and temperature difference of the main-heater, which are used to assess the thermodynamic performance and the compatibility between the thermal storage system and Power cycle. Finally, the trade-off relationships of these metrics are found. The optimal layout, additive and operating parameters are also pointed out based on the comparative results to meet different design requirements. The findings show that the effects of crucial parameters on the performance of SPT system are not monotonous and individual criterion cannot comprehensively evaluate the system performance. Using xenon as an additive can yield excellent performance with higher exergy efficiency and better compatibility between cycle and thermal storage system than the CO2 alone. While the ability to generate specific work is decreased to 105–112 kW·kg−1 with xenon-added that compares to the inter-cooling S-CO2 cycle (121–130 kW·kg−1). When the exergy efficiency is required higher than 33%, the inter-cooling CO2/xenon cycle is the primarily recommended layout for its large specific work and good compatibility between the thermal storage system and cycle. The findings provide a novel way to improve the efficiency of SPT system as well as the compatibility between the cycle and thermal storage system.

  • multi objective optimization of the aiming strategy for the Solar Power Tower with a cavity receiver by using the non dominated sorting genetic algorithm
    Applied Energy, 2017
    Co-Authors: Kun Wang, Yaling He, Baocun Du
    Abstract:

    Abstract The extremely non-uniform Solar flux distribution in the Solar Power Tower plant can badly cause some crucial problems for the Solar receiver such as the local hot spot, the thermal stress, and the thermal deformation. Homogenization of the Solar flux distribution is an effective method to avoid these problems, and has become an important research topic. The objective of the present study is to homogenize the Solar flux distribution on the inner surfaces within the cavity receiver while keeping the optics loss as low as possible by replacing the conventional single-point aiming strategy with optimal multi-point aiming strategies. Multi-objective optimizations of the aiming strategy for the Solar Power Tower with cavity receivers are performed by using the non-dominated sorting genetic algorithm. The distribution of the aiming points on the cavity aperture and the allocation of the aiming points for each heliostat are optimized simultaneously. The following conclusions can be made: (1) The uniformity of the Solar flux distribution on the aperture does not always signify the uniformity of the Solar flux distribution on the inner surfaces, where the later one is what we are truly concerned about. Therefore, the optimization of the aiming strategy should take charge of the Solar flux distribution on the inner surfaces rather than on the aperture. (2) The multi-objective optimization can provide the trade-off between the non-uniformity of the Solar flux distribution and the optics loss in the form of Pareto optimal fronts. (3) The optimal aiming strategies provided by the multi-objective optimization can significantly homogenize the Solar flux distribution on the inner surfaces within the cavity at a minimum cost of optics loss. (4) For the optimal aiming strategies at all time except the noon, there exists a west-east asymmetry of the aiming point distribution on the aperture. Moreover, the asymmetry gets less obvious as the time gets closer to the noon.

  • thermodynamic analysis and optimization of a molten salt Solar Power Tower integrated with a recompression supercritical co2 brayton cycle based on integrated modeling
    Energy Conversion and Management, 2017
    Co-Authors: Kun Wang, Yaling He
    Abstract:

    Abstract In the present study, a molten salt Solar Power Tower (SPT) system integrated with a S-CO 2 Brayton cycle is presented. An integrated model is developed for the integrated SPT system including the heliostat field, the molten salt Solar receiver, the molten salt thermal storage, and the S-CO 2 recompression Brayton cycle with reheating. Parametric analysis is conducted to investigate the effects of some key thermodynamic parameters (e.g. hot salt temperature, cycle high pressure, cycle low pressure, intermediate pressure, and the split ratio) on the integrated SPT system in terms of exergy efficiency. The parameter optimization is performed by using genetic algorithm in order to obtain the highest overall exergy efficiency. The effects of the component performance and the compressor inlet temperature on the optimum parameters are also discussed. The results indicate that the optimum hot salt temperature is 565 °C which is its maximum allowable temperature when the Solar salt is used as the heat transfer fluid and the thermal storage media. Besides, the optimum cycle low pressure is in the range of 7.80–10.0 MPa which means that the cycle low pressure is not mandatory to be close to the critical pressure. The increase in the compressor inlet temperature leads to both the decrease in maximum exergy efficiency and the variation of the optimum thermodynamic parameters. The component performances have significant effects on the maximum exergy efficiency, but slight effects on optimum thermodynamic parameters. A novel salt with a higher maximum allowable temperature is indispensable for further improving the system efficiency. The maximum allowable temperature of 680 °C is recommended for novel salts to be used in the SPT system integrated with S-CO 2 recompression Brayton cycle from the viewpoint of exergy efficiency under the present conditions.

  • a comprehensive model for analysis of real time optical performance of a Solar Power Tower with a multi tube cavity receiver
    Applied Energy, 2017
    Co-Authors: Yaling He, Peiwen Li, Baocun Du
    Abstract:

    A comprehensive model and corresponding code named after SPTOPTIC for analysis of the real-time optical performance of a Solar Power Tower (SPT) with a Multi-Tube Cavity Receiver (MTCR) were developed using Monte Carlo Ray Tracing (MCRT) method. After validation, the model was used to study the optical performance of the DAHAN plant. The model-obtained results show that the Solar flux in the MTCR exhibits a significant non-uniformity, showing a maximum flux of 5.141×105Wm−2 on the tubes. A comparison of the tracking models indicates that it is a good practice to treat the tracking errors as the random errors of the tracking angles when considering the random effect on the Solar flux distribution. Study also indicates that multi-point aiming strategy of tracking helps homogenizing the flux and reducing the energy maldistribution among the tubes. Additionally, time-dependent optical efficiencies were investigated, and the yearly efficiency for the energy absorbed by the tubes was found to be 65.9%. At the end of the study, the cavity effect on the efficiency was revealed quantitatively, which indicates that the optical loss can be reduced significantly by the cavity effect, especially when the coating absorptivity is relatively low. It is concluded that the present model is reliable and suitable for predicting both the detailed real-time Solar flux and the real-time efficiency of SPT.

  • Optical performance analysis of a porous open volumetric air receiver in a Solar Power Tower
    arXiv: General Physics, 2016
    Co-Authors: Ming-jia Li, Yaling He, Ze-dong Cheng
    Abstract:

    An optical model for a Solar Power Tower with an open volumetric air receiver (OVAR) was developed in this paper, and the optical performance and characteristics of the OVAR were studied based on the model. Firstly, the detailed distributions of the non-uniform Solar flux (qsr) on the aperture and the Solar source (Ssr) in the OVAR were studied. The Solar flux was found to be relatively uniform across the aperture for a single OVAR. However the incident angle of the rays varies between 0o and 42o, which indicates that the parallel assumption of the rays is not appropriate at this condition. Furthermore, the Ssr in the absorber decreases from the inlet to the outlet, and the maximum source (Ssr,max) of 2.414X108 Wm-3 appears at the inlet. Moreover, the Ssr,max was found to appear at the region near the wall rather than the center of the receiver as usual for the combined effect of the non-parallel incident rays and the diffuse reflection on the wall. In addition, study on effects of the porous parameters indicates that the solid emissivity influences both the Ssr distribution and the receiver efficiency significantly. However, the pore diameter and the porosity influence Ssr distribution importantly, but have negligible effect on the efficiency. Finally, the optical efficiency of 86.70%, reflection loss of 13.20% and transmission loss of 0.10% were found to be achieved by the OVAR.

Zhifeng Wang - One of the best experts on this subject based on the ideXlab platform.

  • Study on Optimized Dispatch and Operation Strategies for Heliostat Fields in a Concentrated Solar Power Tower Plant
    Energies, 2019
    Co-Authors: Qiang Yu, Zhifeng Wang
    Abstract:

    Concerning Solar flux densities during the operation of a concentrated Solar Power Tower plant, their uneven distribution on a central receiver not only leads to abrupt variations of thermal gradient on the receiver surface but also makes it possible for the receiver to break down. Specific to such problems, a “concentrating-receiver” coupling system of a 1 MWe concentrated Solar Power Tower plant in Yanqing was selected as the research object. On this basis, a spliced heliostat model was firstly established in this paper. The model was used to investigate Solar flux distribution on the receiver surface. Considering that heliostats in different positions make diverse contributions to receiver surface energy and the incidence cosines of adjacent heliostats are similar to each other, a new grouping method for heliostat fields was subsequently proposed; moreover, focal point selection criteria were designed for the receiver surface according to Solar spot sizes. Finally, an optimized dispatch and operation strategy was established based on the genetic algorithm for the heliostat field. Therefore, a standard deviation of Solar flux distribution can be minimized. To verify the reliability of the established model and the proposed strategy, a small-scale heliostat field was adopted to check the simulation results by means of experiments. It has been demonstrated that a heliostat field subjected to optimized dispatch makes Solar flux densities distribute more uniformly on the receiver surface. Hence, the safe and steady operation of the receiver is guaranteed.

  • Design of Heliostats Field for the Scale of 1MW Solar Power Tower Plant
    2012 Asia-Pacific Power and Energy Engineering Conference, 2012
    Co-Authors: Hongli Zhang, Zhifeng Wang, Zhenwu Lu
    Abstract:

    The development in basic technology and market strategy of Solar thermal Power techniques is booming rapidly due to the limited fossil resources and severe environmental problems all over the world. In this paper, the design method of heliostats field for the scale of 1MW Solar Power Tower plant with latitude of 40.4°N at the design point of the noon of spring equinox is introduced, which uses the multiplication of three efficiencies of cosine, atmospheric transmittance and intercept as the preliminary boundary limit to locate heliostats, while the spacing between heliostats is set not only for less shading and blocking, but also for the availability of installation and maintenance of heliostats. Furthermore, its optical performance tested by the software HFLD, is quite good, which has annual average efficiency of 71.36% and design point efficiency of 80%.

  • dynamic simulation of thermal energy storage system of badaling 1 mw Solar Power Tower plant
    Renewable Energy, 2012
    Co-Authors: Ershu Xu, Zhifeng Wang, Gao Wei, Jiayan Zhuang
    Abstract:

    In this paper, the thermal energy storage system of Badaling 1 MW Solar Power Tower plant is modelled from mathematical models for whole of the working conditions using the modular modelling method. This model can accurately simulate the recharge and discharge processes of thermal energy storage system. The dynamic and static characteristics of the thermal energy storage system are analyzed based on the model response curves of the system state parameters that are obtained from different steam flow disturbances. Conclusions of this paper are good references for the design, operating, and control strategy of Solar thermal Power plant.

  • energy and exergy analysis of Solar Power Tower plants
    Applied Thermal Engineering, 2011
    Co-Authors: Chao Xu, Zhifeng Wang, Xin Li
    Abstract:

    Establishing the renewable electricity contribution from Solar thermal Power systems based on energy analysis alone cannot legitimately be complete unless the exergy concept becomes a part of that analysis. This paper presents a theoretical framework for the energy analysis and exergy analysis of the Solar Power Tower system using molten salt as the heat transfer fluid. Both the energy losses and exergy losses in each component and in the overall system are evaluated to identify the causes and locations of the thermodynamic imperfection. Several design parameters including the direct normal irradiation (DNI), the concentration ratio, and the type of Power cycle are also tested to evaluate their effects on the energy and exergy performance. The results show that the maximum exergy loss occurs in the receiver system, followed by the heliostat field system, although main energy loss occurs in the Power cycle system. The energy and exergy efficiencies of the receiver and the overall system can be increased by increasing the DNI and the concentration ratio, but that increment in the efficiencies varies with the values of DNI and the concentration ratio. It is also found that the overall energy and exergy efficiencies of the Solar Tower system can be increased to some extent by integrating advanced Power cycles including reheat Rankine cycles and supercritical Rankine cycles.

  • Design and analysis of a novel heliostat structure
    2009 International Conference on Sustainable Power Generation and Supply, 2009
    Co-Authors: Chuncheng Zang, Zhifeng Wang
    Abstract:

    Heliostat is a sun-tracking device in the Solar Power Tower system and there are mainly two modes for heliostat to track the sun: azimuth-elevation mode and spinning-elevation mode. The heliostat tracking in the former mode has commonly been developed and applied. In this paper, the novel heliostat structure in the latter mode is presented. Furthermore, the static and dynamic performance of the heliostat structure under wind load is analyzed by means of the finite element method. Static analysis describes the intensity and rigidity performance of the structure and dynamic analysis presents the first several orders natural frequency and vibration mode, which provide theoretical basis for the structure optimization.

Jiayan Zhuang - One of the best experts on this subject based on the ideXlab platform.

  • dynamic simulation of thermal energy storage system of badaling 1 mw Solar Power Tower plant
    Renewable Energy, 2012
    Co-Authors: Ershu Xu, Zhifeng Wang, Gao Wei, Jiayan Zhuang
    Abstract:

    In this paper, the thermal energy storage system of Badaling 1 MW Solar Power Tower plant is modelled from mathematical models for whole of the working conditions using the modular modelling method. This model can accurately simulate the recharge and discharge processes of thermal energy storage system. The dynamic and static characteristics of the thermal energy storage system are analyzed based on the model response curves of the system state parameters that are obtained from different steam flow disturbances. Conclusions of this paper are good references for the design, operating, and control strategy of Solar thermal Power plant.

  • Performance Analysis of Two-Stage Thermal Energy Storage System of Solar Power Tower Plant
    2011 Asia-Pacific Power and Energy Engineering Conference, 2011
    Co-Authors: Jiayan Zhuang, Ershu Xu
    Abstract:

    Based on the principles of mass, energy conservation and state equation for ideal gas, operation performance of two-stage thermal energy storage system of the first 1MW Solar Tower Power plant in China was calculated and analyzed using numerical simulation method. The results indicated that the pressure of nitrogen in oil tanks slightly changes as a function of temperature and volume variation, thus it is not necessary to control pressure by nitrogen recharge and freeing in normal operation. The steam mass flow rate of discharging process is dependent on pressure variation rate of steam accumulator. Steam mass flow rate increases rapidly to the controlled maximum while pressure varies with time as exponential function. For the case of pressure decreases with time as linear function, the steam mass flow rate increases with time. The steam accumulator needs periodic water supplement because a small quantity of water was lost after every cycle of charging and discharging process.

Kun Wang - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic performance analysis of different supercritical brayton cycles using co2 based binary mixtures in the molten salt Solar Power Tower systems
    Energy, 2019
    Co-Authors: Ming-jia Li, Kun Wang, Jinliang Xu
    Abstract:

    Abstract The potential to improve the performance of molten salt Solar Power Tower system (SPT) is explored through the proposal of CO2-based binary mixture cycle in the present study. The feasibility of using xenon and butane as the additives to the S-CO2 cycle are discussed from the perspective of thermodynamic analysis. The detail parametric study is performed to reveal the effects of crucial parameters on the performance of 4 system configurations. Furthermore, the systematic comparison is conducted for 4 cycle layouts adopting CO2/xenon, CO2 and CO2/butane separately to illustrate the mechanism of performance improvement of SPT system coupled to CO2-based binary mixture cycle. The optimal performance of the SPT system is also demonstrated. Finally, the best performance system layout and suitable additives are recommended. The results indicate the following issues. Adding xenon into S-CO2 cycle can obviously improve the overall thermal efficiency and exergy efficiency. While the effects of butane as an additive are converse. The inter-cooling CO2/xenon cycle is recommended as the most suitable layout coupled to the SPT system, and the exergy efficiency is 1.18%∼1.32% higher than that of the SPT system with S-CO2 inter-cooling cycle. Detail exergy loss fraction distribution illustrates that the receiver is the highest exergy loss part and followed by the heliostat field, and butane as an additive is beneficial to reduce the receiver exergy loss for its smaller temperature difference. The study can provide a novel way to improve the SPT system performance and give a clue to the addition of CO2-based binary mixture in Power cycles particularly for the application of SPT system.

  • a systematic comparison of different s co2 brayton cycle layouts based on multi objective optimization for applications in Solar Power Tower plants
    Applied Energy, 2018
    Co-Authors: Kun Wang, Ming-jia Li, Peiwen Li
    Abstract:

    Supercritical CO2 (S-CO2) Brayton cycles are recently proposed to be integrated into the Solar Power Tower (SPT) due to their high efficiency and compactness. Comparison of different S-CO2 Brayton cycle layouts is of great significance for selecting a suitable one in the SPT plant. Both of the efficiency and specific work are important performance criteria for the SPT plant. However, previous studies compared only one individual criterion, or both of them just separately. This paper puts forward a systematic comparison of different S-CO2 Brayton cycle layouts based on multi-objective optimizations. The two performance criteria are compared simultaneously between different S-CO2 cycle layouts by comparing the Pareto optimal fronts obtained from multi-objective optimizations. The results suggest that the inter-cooling cycle layout and the partial-cooling cycle layout can generally yield the most excellent performances, and followed by the recompression cycle layout and the pre-compression cycle layout, while the simple recuperation cycle layout has the worst performances. The advantages of the partial-cooling cycle layout and the inter-cooling cycle layout are more prominent compared with the other cycle layouts in the case of high compressor inlet temperature. The provided systematic comparison can be helpful in selecting the most suitable cycle layout for the application in SPT when there are specified requirements for the efficiency and the specific work. In addition, novel salts with high upper limit temperature (higher than 650 °C) are recommended to be developed as the heat transfer fluid for improving system performances.

  • multi objective optimization of the aiming strategy for the Solar Power Tower with a cavity receiver by using the non dominated sorting genetic algorithm
    Applied Energy, 2017
    Co-Authors: Kun Wang, Yaling He, Baocun Du
    Abstract:

    Abstract The extremely non-uniform Solar flux distribution in the Solar Power Tower plant can badly cause some crucial problems for the Solar receiver such as the local hot spot, the thermal stress, and the thermal deformation. Homogenization of the Solar flux distribution is an effective method to avoid these problems, and has become an important research topic. The objective of the present study is to homogenize the Solar flux distribution on the inner surfaces within the cavity receiver while keeping the optics loss as low as possible by replacing the conventional single-point aiming strategy with optimal multi-point aiming strategies. Multi-objective optimizations of the aiming strategy for the Solar Power Tower with cavity receivers are performed by using the non-dominated sorting genetic algorithm. The distribution of the aiming points on the cavity aperture and the allocation of the aiming points for each heliostat are optimized simultaneously. The following conclusions can be made: (1) The uniformity of the Solar flux distribution on the aperture does not always signify the uniformity of the Solar flux distribution on the inner surfaces, where the later one is what we are truly concerned about. Therefore, the optimization of the aiming strategy should take charge of the Solar flux distribution on the inner surfaces rather than on the aperture. (2) The multi-objective optimization can provide the trade-off between the non-uniformity of the Solar flux distribution and the optics loss in the form of Pareto optimal fronts. (3) The optimal aiming strategies provided by the multi-objective optimization can significantly homogenize the Solar flux distribution on the inner surfaces within the cavity at a minimum cost of optics loss. (4) For the optimal aiming strategies at all time except the noon, there exists a west-east asymmetry of the aiming point distribution on the aperture. Moreover, the asymmetry gets less obvious as the time gets closer to the noon.

  • thermodynamic analysis and optimization of a molten salt Solar Power Tower integrated with a recompression supercritical co2 brayton cycle based on integrated modeling
    Energy Conversion and Management, 2017
    Co-Authors: Kun Wang, Yaling He
    Abstract:

    Abstract In the present study, a molten salt Solar Power Tower (SPT) system integrated with a S-CO 2 Brayton cycle is presented. An integrated model is developed for the integrated SPT system including the heliostat field, the molten salt Solar receiver, the molten salt thermal storage, and the S-CO 2 recompression Brayton cycle with reheating. Parametric analysis is conducted to investigate the effects of some key thermodynamic parameters (e.g. hot salt temperature, cycle high pressure, cycle low pressure, intermediate pressure, and the split ratio) on the integrated SPT system in terms of exergy efficiency. The parameter optimization is performed by using genetic algorithm in order to obtain the highest overall exergy efficiency. The effects of the component performance and the compressor inlet temperature on the optimum parameters are also discussed. The results indicate that the optimum hot salt temperature is 565 °C which is its maximum allowable temperature when the Solar salt is used as the heat transfer fluid and the thermal storage media. Besides, the optimum cycle low pressure is in the range of 7.80–10.0 MPa which means that the cycle low pressure is not mandatory to be close to the critical pressure. The increase in the compressor inlet temperature leads to both the decrease in maximum exergy efficiency and the variation of the optimum thermodynamic parameters. The component performances have significant effects on the maximum exergy efficiency, but slight effects on optimum thermodynamic parameters. A novel salt with a higher maximum allowable temperature is indispensable for further improving the system efficiency. The maximum allowable temperature of 680 °C is recommended for novel salts to be used in the SPT system integrated with S-CO 2 recompression Brayton cycle from the viewpoint of exergy efficiency under the present conditions.

  • a novel integrated simulation approach couples mcrt and gebhart methods to simulate Solar radiation transfer in a Solar Power Tower system with a cavity receiver
    Renewable Energy, 2016
    Co-Authors: Kun Wang, Yaling He, Yuwen Zhang
    Abstract:

    An integrated simulation approach, which couples Monte Carlo ray tracing (MCRT) and Gebhart methods, is proposed to simulate Solar radiation transfer in a Solar Power Tower system with a cavity receiver. The MCRT method is used to simulate the Solar radiation transfer process from the heliostat field to interior surfaces of the cavity receiver, and the Gebhart method is used to simulate the multiple reflections process of Solar radiation within the cavity. This integrated simulation method not only reveals the cavity effect on receiver performance but also provides real-time simulation results. Based on this method, the reflection loss of the cavity receiver and Solar flux distributions are discussed in detail. The results indicate that the cavity effect can significantly reduce the reflection loss and homogenize the concentrated Solar energy distributed on interior surfaces to some extent. Moreover, the surface absorptivity has less effect on the reflection loss when cavity effect is considered. The cavity effect on homogenizing Solar flux distributions is greater with lower surface absorptivity. In addition, although the concentrated Solar energy is distributed on the cavity aperture with similar shapes at different times, the shape of the Solar flux distribution on interior surfaces varies greatly with time.

Xiaoze Du - One of the best experts on this subject based on the ideXlab platform.

  • Novel optimization design strategy for Solar Power Tower plants
    Energy Conversion and Management, 2018
    Co-Authors: Tao Lu, Xiaoze Du
    Abstract:

    Abstract A novel strategy using the Sobol’-Simulated Annealing algorithm was proposed to reduce the number of optimization steps and guarantee the accuracy of a molten salt Solar Power Tower plant design. The new method combined the Sobol’ method and the Simulated Annealing algorithm for global sensitivity analysis and global optimization, respectively. Based on the sensitivity analysis, the high-dimension global optimization problem was transformed into several low-dimension global optimization problems by parameter decoupling. In order to obtain the global minimum levelized cost of electricity of the Solar Power Tower plant, these low-dimension models were successively optimized by utilizing the Simulated Annealing algorithm. A reference case study of the Solar Power Tower plant with 2650 heliostats was conducted. The heliostat field, receiver, thermal storage system and Power block were designed as a function of 12 parameters. It was demonstrated that the parameters related to the heliostat field and receiver were almost independent. The minimum levelized cost of electricity of 22.22 ȼ/kWhe was obtained. Furthermore, a comparison with the global algorithm and local algorithm showed that the novel method could reduce the number of optimization steps by approximately 75% compared with that of the global algorithm. A much more accurate optimal design than that of the local algorithm can be achieved herewith.

  • Impacts of Solar multiple on the performance of direct steam generation Solar Power Tower plant with integrated thermal storage
    Frontiers in energy, 2017
    Co-Authors: Xiaoze Du, Chao Xu, Lijun Yang, Muhammad Amjad
    Abstract:

    Solar multiple (SM) and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation (DSG) Solar Power Tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity (LCOE) by adjusting the Power generation output. Taking the dual-receiver DSG Solar Power Tower plant with a given size of Solar field equivalent electricity of 100 MWe in Sevilla as a reference case, the minimum LCOE is 21.77¢/kWhe with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of Solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of Solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms of optimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of Power generation unit.

  • Impacts of Solar multiple on the performance of direct steam generation Solar Power Tower plant with integrated thermal storage
    Frontiers in Energy, 2017
    Co-Authors: Yan Luo, Xiaoze Du, Chao Xu, Lijun Yang, Muhammad Amjad
    Abstract:

    © 2017, Higher Education Press and Springer-Verlag GmbH Germany. Solar multiple (SM) and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation (DSG) Solar Power Tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity (LCOE) by adjusting the Power generation output. Taking the dual-receiver DSG Solar Power Tower plant with a given size of Solar field equivalent electricity of 100 MWe in Sevilla as a reference case, the minimum LCOE is 21.77¢/kWhe with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of Solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of Solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms of optimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of Power generation unit.

  • novel design of central dual receiver for Solar Power Tower
    Applied Thermal Engineering, 2015
    Co-Authors: Xiaoze Du
    Abstract:

    A novel dual-receiver with a surrounding Solar field was proposed to improve the efficiency of a Solar Power Tower (SPT). The new design combined an external and a cavity receiver, corresponding to the boiling and superheating sections respectively, and provided a simple yet controllable heat flux distribution on both sections. A case study of a 11 MW Solar Power plant was conducted. It was demonstrated that the present dual-receiver could produce superheated steam of 515 °C and 10.7 MPa at an impressive Solar heat absorbing efficiency of 86.55%. By considering various heat losses, the surface heat flux, the surface temperature and the heat transfer fluid distribution were obtained for the dual-receiver. A comparison with a two-external cylindrical receiver showed that the present design could improve the global thermal efficiency by 3.2%. Off-design performance of the dual-receiver indicated that the plant performance was affected significantly by the incident Solar fluxes at different times of a day. The influence of heat transfer tube size suggested that an optimized tube diameter for the superheating section of the present dual-receiver should be used.