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Study on the Dynamic Characteristics, Control Strategy and Load Variation Rate of the Concentrated Solar Power Plant

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SSRN 2023年

作者： Li, Gen Du, Guanghan Liu, Guixiu School of Electric Power Engineering South China University of Technology Guangzhou510641 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

With more and more wind power and photovoltaic power connected to the electric power system, it has brought great challenges to the stability of the power grid. Concentrated solar power (CSP) plant as one form of solar power generation can undertake the task of load regulation and frequency regulation in power grid to balance the electricity demand and generation. However, the maximum load variation rate of the CSP plant is not known, which limits sufficient utilization of its advantages. In this study, a dynamic simulation model of the CSP plant was built using the APROS, and the dynamic characteristics were investigated by applying the step disturbances to molten salt flowrate, molten salt temperature, and the opening of steam regulating valve. Based on the results of dynamic characteristics, the control strategies were developed with the consideration of thermal storage in system and the feedforward signal of set load and load variation rate. Then, the maximum load increase and reduction rates within different load ranges were studied. The results indicated that the steam regulating valve could be used to control turbine power, molten salt flowrate could be used to control steam pressure, and the molten salt temperature could be used to control steam temperature. The designed control system could effectively follow the load variation, with the load deviation less than 0.3 MW and the steam temperature deviation less than 1.2 ℃ in the condition of load variation rate at 3% Pe·min-1. The maximum load increase and reduction rates were 11.57% Pe·min-1 and 8.94% Pe·min-1 within the load range of 75%THA-100%THA, and they were 10.42% Pe·min-1 and 7.46% Pe·min-1 within the load range of 50%THA-75%THA, respectively. © 2023, The Authors. All rights reserved.

关键词： Concentrated solar power

Investigation of the Solar-Driven Chemical Looping Methane Dry Reforming on Rh-Doped LaCeO3.5 Oxygen Carrier

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SSRN 2024年

作者： Li, Peng Gai, Zhongrui Zhang, Jinrui Rao, Qiong Tang, Sanli Shen, Yuanhui Pan, Ying Jin, Hongguang Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China University of Chinese Academy of Sciences Beijing100049 China

The feasibility of a solar-driven chemical looping dry reforming of methane (DRM) process, which converts solar energy and methane into syngas via a looping material oxygen carrier is investigated experimentally. Thermogravimetric analysis (TGA) experiments were firstly carried out to verify the effect of the Rh-doped LaCeO3.5 which were synthesized via modified Pechini method and incipient wetness method and the result shows that Rh greatly improved the reaction kinetics. Photo-TGA experiments were conducted to evaluate the light effect in chemical looping DRM. Under the light condition, the Rh-doped LaCeO3.5 shows higher methane conversion, oxygen extraction rate and CO selectivity compared with the undoped one, decreasing the apparent activation energy of the reaction at the same time. Insights obtained from the UV-Vis spectroscopy verified that the surface Rh under the light could promote the activation of surface methane species and increase the light absorbance. Meanwhile, the FEM methods were used to obtain the distributions of the temperature fields of the photo-TGA reactor through the calculation of the coupling of the fluid, reaction and temperature fields. In this way, the conversion mechanism of the solar, heating and chemical energy was illustrated and furthermore, the calculated surface reaction rate and the variation tendency of the outlet-gas were consistent with the experimental results. Through the integration of solar energy, a high methane to solar fuel conversion efficiency could be achieved. The proposed process has the potential to produce solar fuels at high efficiency with reduced carbon footprint. © 2024, The Authors. All rights reserved.

关键词： Methane

Control of two-phase flow around a cylinder with a cylindrical attachment: A numerical study

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Ocean engineering 2025年 334卷

作者： Wang, Ziqing Hu, Yu Huang, Shengxian Zhang, Yongxing Moghtaderi, Behdad Wang, Ying Shanghai Key Laboratory of Multiphase Flow and Heat Transfer of Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai China National Engineering Laboratory for Pipeline Safety/MOE Key Laboratory of Petroleum Engineering/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of Petroleum – Beijing Beijing102249 China Centre for Innovative Energy Technologies The University of Newcastle CallaghanNSW2308 Australia

Mitigating flow separation, vortex shedding and sediment-induced erosion around cylindrical structures is critical for enhancing marine engineering safety. This study investigates the hydrodynamic performance of a two-phase flow around a cylinder equipped with an auxiliary cylinder under realistic ocean conditions. key parameters include the clearance ratio (G/D), particle characteristics (size and concentration), and vibration modes of the auxiliary body. This study investigates real ocean conditions, focusing on the influence of clearance ratio (G/D) and an auxiliary cylinder on flow field changes with varying particle characteristics. The results demonstrate that: (1) A clearance ratio G/D = 0.1 yields the optimal drag reduction (57.18 %) for the primary cylinder in single-phase flow;(2) Larger particles weaken vortex-particle interactions, while higher particle concentrations exacerbate uneven deposition near the cylinder;(3) Transverse vibration of the auxiliary body (amplitude ratio = 0.025, frequency ratio = 0.65) reduces drag by 18.7 % compared to stationary configurations. These findings provide insights into flow control strategies for offshore structures subjected to sediment-laden flows. © 2025 Elsevier Ltd

关键词： Marine safety

Ionic liquid catalyzed solvent-free synthesis of chalcone and its derivatives under mild conditions

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Chinese Journal of Chemical engineering 2021年第5期34卷 160-166页

作者： Qiu Zhao Gang Wang Fuxia Liao Yifan Sha Fei Xu Chunshan Li Zengxi Li Yijun Cao School of Chemical Engineering and Energy Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex SystemsBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

An ionic liquid(IL)catalyzed solvent-free process was developed for the direct synthesis of chalcone and its derivatives by using substituted acetophenones and benzaldehydes via aldol reaction under mild conditions.A series of acidic and basic ILs were selected and *** influences of cations and reaction conditions on product yield and selectivity were systematically ***[Bmim]OH was identified as the optimal IL,with the highest yield and selectivity reaching up to 96.7% and 100%,respectively.A reaction mechanism-based kinetic model was established and regressed with experimental data,revealing the β-Hydroxylketone dehydrolysis with activation barrier of 37.8 kJ·mol^(-1) was observed as the ratecontrolling step.

关键词： Ionic liquid Chalcone Aldol reaction Kinetic model

A Novel Mass-Heat Exchange Network Analogy, Regression, and Synthesis Method for Mass Exchanger Networks

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SSRN 2023年

作者： Xiao, Yuan Cui, Guomin Shanghai Key Laboratory Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai20093 China

The mass exchanger network (MEN) synthesis is significant for material savings and pollution reduction in process industries. Considering its small magnitude and the concentration constraints, the optimized MEN configuration could easily violate the concentration constraints, leading to a reduction in the structural diversity during the optimization process compared to that of an heat exchanger network （HEN）of the same size. Moreover, the constraint on the mass transfer driving force based on the equilibrium composition might also have major effects on the optimization process. To address this, this paper presents a process-equipment-system analogy between the MEN and the HEN, proposing a novel mass-heat exchange network analogy, regression, and synthesis method. First, the generalized HEN was established by an analogy considering the MEN based on either the original or the equilibrium compositions. In this regard, a coordination coefficient was introduced to correct the deviation of the analogy relationship between the heat transfer and the mass transfer processes. Then, the generalized HEN was optimized by employing the random walk algorithm with compulsive evolution (RWCE). A regression method was proposed to regress the optimized HEN solution to the MEN expression, allowing the continuous optimization by the RWCE with finer parameters. The final optimal solution obtained is found to be lower than those reported in the literature with enhanced structural diversity, demonstrating the method’s effectiveness and providing new ideas for further synchronous optimization of combined heat and mass exchanger networks. © 2023, The Authors. All rights reserved.

关键词： Mass transfer

Numerical Investigation on the Thermal-Hydraulic Performance of a Cryogenic Printed Circuit Heat Exchanger for Liquid Air Energy Storage

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SSRN 2022年

作者： Yu, Pengfei Liu, Hu Xue, Jingwen Zhang, Yankang Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'An710049 China

The liquid air energy storage integrated with liquefied natural gas regasification is a promising large-scale storage method, but its development is limited by the lack of the thermal-hydraulic data of the cryogenic printed circuit heat exchanger. In this paper, a reduced numerical model for conjugate heat transfer was established, and the effect of the inclined angle (0°, 15°, 30°, 45°, and 60°) was investigated. The minimum internal temperature approach for optimal system operation is approximately 6 K, located in the middle of the heat exchanger. The nature of local flow and heat transfer was analyzed by quantifying the vortex strength and visualizing the vortex core. Results indicate that the evolution of Dean vortices plays a crucial role in heat transfer augmentation. The secondary flow caused by the elbow forces the velocity and temperature cores to strike the windward side periodically, which disturbs the boundary layer and enhances the fluid mixing. Entropy production analysis shows that the thermal entropy generation has a dominant share of the irreversibility. The zigzag channel with an inclined angle of 45° yields the best comprehensive performance since the irreversibility is reduced by augmenting the heat transfer. © 2022, The Authors. All rights reserved.

关键词： Air

Synthesis of Co3o4@C/Ti3c2tx Mxene-Type Composites for Enhanced Electromagnetic Wave Absorption

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SSRN 2024年

作者： Hou, Yunxi Jia, Zhen Zheng, Hanli Hu, Zewei Shen, Lu Liu, Dongyu Li, Lu Liu, Shiwei Liu, Yue Yu, Shitao Key Laboratory of Multiphase Flow Reaction and Separation Engineering of Shandong Province State Key Laboratory Base of Eco-chemical Engineering College of Chemical Engineering Qingdao University of Science and Technology Qingdao266042 China A VIC Research Institute for Special Structures of Aeronautical Composites 19 Jiqi Road Jinan250000 China

Highly efficient microwave absorbing materials have attracted widespread attention due to the harmful effects of electromagnetic pollution on the human body and electronic equipment. In this paper, Co3O4@C composites with core-shell structure were prepared by hydrothermal method using a simple strategy, and then Ti3C2Tx was assembled with core-shell Co3O4@C by electrostatic self-assembly method, which resulted in the successful attachment of Co3O4@C to the lamellar structure of Ti3C2Tx and the formation of MXene-based composite wave-absorbing Co3O4@C/Ti3C2Tx material. The composites exhibit strong electromagnetic wave absorption when the mass ratio of Co3O4@C to Ti3C2Tx was 1:2, with a minimum reflection loss of -35.2 dB at a matched thickness of only 4.5 mm. Excellent electromagnetic wave absorption performance Co3O4@C/Ti3C2Tx composite material was mainly attributed to the synergistic effect of the multiple reflection absorption of the core-shell structure and the high conductivity and large specific surface area of MXene material. These results indicate that Co3O4@C/Ti3C2Tx composites were promising candidates for electromagnetic absorption and provide new ideas for the design of MXene-based magnetic absorption materials. © 2024, The Authors. All rights reserved.

关键词： Composite materials

Morphology Construction of Molybdenum Doped Nickel Sulfide Electrocatalyst Induced by Nh4f to Promote Hydrogen Evolution Reaction

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SSRN 2024年

作者： Zhang, Baikai Li, Xiaohui Liu, Maochang Huadian Electric Power Research Institute Co. Ltd. Zhejiang310030 China School of Eenergy and Power Engineering Xi’an Jiaotong University Shaanxi 710049 China State Key Laboratory of Multiphase Flow in Power Engineering China

Here, by varying the mass of NH4F throughout the hydrothermal process, Mo-doped nickel-based sulfide catalysts (Mo-NiS-Fx) with various morphologies (prisms, rods, flakes, and cones) were created. Among these, the flaky Mo-NiS-F1.2 exhibited exceptional performance towards electrochemical hydrogen evolution reaction, surpassing most similar catalysts with an overpotential of 79 mV at 10 mA cm-2 and a Tafel slope of 49.8 mV dec-1. Significantly, Mo-NiS-F1.2 maintained its high activity for hydrogen evolution over 60 h at 10 mA cm-2, making it suitable for widespread commercial application. This work demonstrates the potential of morphology manipulation to enhance catalytic activity. © 2024, The Authors. All rights reserved.

关键词： Hydrogen

Numerical Study of Multi-Factor Coupling Effects on Energy Conversion Performance of Nanofluidic Reverse Electrodialysis

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Frontiers in Heat and Mass Transfer 2025年第2期23卷 507-528页

作者： Hao Li Cunlu Zhao Jinhui Zhou Jun Zhang Hui Wang Yanmei Jiao Yugang Zhao School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing211816China MOE Key Laboratory of Thermo-Fluid Science and Engineering Xi’an Jiaotong UniversityXi’an710049China Key Laboratory of Unsteady Aerodynamics and Flow Control Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing210016China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai200093China Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang621000China

Based on the rapid advancements in nanomaterials and nanotechnology,the Nanofluidic Reverse Electrodialysis(NRED)has attracted significant attention as an innovative and promising energy conversion strategy for extracting sustainable and clean energy fromthe salinity gradient ***,the scarcity of research investigating the intricate multi-factor coupling effects on the energy conversion performance,especially the trade-offs between ion selectivity and mass transfer in nanochannels,of NRED poses a great challenge to achieving breakthroughs in energy conversion *** numerical study innovatively investigates the multi-factor coupling effect of three critical operational factors,including the nanochannel configuration,the temperature field,and the concentration difference,on the energy conversion processes of *** this work,a dimensionless amplitude parameter s is introduced to emulate the randomly varied wall configuration of nanochannels that inherently occur in practical applications,thereby enhancing the realism and applicability of our *** results reveal that the application of a temperature gradient,which is oriented in opposition to the concentration gradient,enhances the ion transportation and selectivity simultaneously,leading to an enhancement in both output power and energy conversion ***,the increased fluctuation of the nanochannel wall from s=0 to s=0.08 improves ion selectivity yet raises ion transport resistance,resulting in an enhancement in output power and energy conversion efficiency but a slight reduction in ***,with increasing the concentration ratio cH/cL from 10 to 1000,either within a fixed temperature field or at a constant dimensionless amplitude,the maximumpower consistently attains its optimal value at a concentration ratio of 100 but the cation transfer number experiences amonotonic decrease across this entire range of concentration ***,uponmodifying the ope

关键词： Salinity gradient energy nanofluidic reverse electrodialysis energy conversion nanochannel configuration multi-factor coupling effect