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Study on TMD Control on Stability Improvement of Barge-Supported Floating Offshore Wind Turbine Based on the Multi-Island Genetic Algorithm

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China Ocean engineering 2019年第3期33卷 309-321页

作者： DING Qin-wei LI Chun CHENG Shan-shan HAO Wen-xing HUANG Zhi-qian YU Wan School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093 China School of Engineering University of Plymouth Devon PL4 8AA UK

A floating offshore wind turbine (FOWT) has a great potential in producing renewable energy as offshore wind resource is rich in deep sea area (water deeper than 60 m) where fixed foundations are cost-effective or deployable. However, compared with a fixed-bottom installation, FOWT has to suffer more extreme loads due to its extra degrees of freedom. Therefore, the stability of an FOWT is a key challenge in exploiting offshore deep-water wind. Focusing on the stability of barge-type FOWT, this paper is to investigate the effect of passive structural control by equipping a tuned mass damper (TMD) on the nacelle. The turbulent wind with sharp fluctuations is established both in velocity and inflow direction based on standard Kaimal turbulence spectrum as suggested in the standard IEC61400-2. The irregular wave is generated according to the Pierson-Moskowitz spectrum. The dynamic structural characteristics of FOWT are calculated based on the fully coupled aero-hydro-servo-elastic solver FAST. Evidence has shown that the proposed method of the nacelle-based TMD is effective in controlling stability of an FOWT, as the sway and roll motions of barge and the side-side displacement of tower top decreased significantly. With the increase of mass, the side-side displacement of tower-top and the amplitude of roll motion of barge reveal a trend of increasing first and then decreasing. The stiffness and damping have little effect. Furthermore, the multi-island genetic optimization algorithm (MIGA) is employed to find globally optimum structural parameters (mass, stiffness and damping) of the TMD. The optimum structure parameters of TMD are achieved when the mass is 21393 kg, damping is 13635 N/(m/s) and stiffness is 6828 N/m. By adopting the optimized TMD, stability of roll motion of barge and side-side displacement of tower-top increase up to 53% and 50% respectively when compared with the normal TMD. The simulation results verify the validity and reliability of the proposed TM

关键词： FOWT barge TMD MIGA wind wave stability

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3 μm Hydrocarbon Gas Absorption Detection Based on DFG-TDLAS

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Guangxue Xuebao/Acta Optica Sinica 2025年第8期45卷

作者： Zhou, Wangzheng Qi, Chao Qin, Xiaowei Wang, Zhenzhen Yoshihiro, Deguchi Chong, Daotong Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Graduate School of Technology Industrial and Social Sciences Tokushima University Tokushima770-8506 Japan Xi’an Aerospace Propulsion Institute Shaanxi Xi’an710100 China

Objective To achieve in-situ online detection of hydrocarbon gases at various temperatures, we explore the use of tunable diode laser absorption spectroscopy (TDLAS) for measuring hydrocarbon gas content. A difference frequency generation (DFG) laser, with a scanning range of 3250-3400 nm, is used to construct a hydrocarbon gas detection system. The 3 μm wide-band scanning provides a significant number of characteristic absorption peaks and reveals the absorbance line shapes of the absorption band. This makes hyperspectral fitting feasible and enhances the system’s versatility. Methods First, the DFG-TDLAS system and hydrocarbon gas detection experimental setup are established. The DFG-TDLAS system includes a 1060 nm ECDL, a 1582 nm DFB laser, a WDM fiber coupler, and a PPLN module. This system can achieve 3250-3400 nm laser output with a resolution of 0.01 cm-1. The hydrocarbon gas detection experimental system includes a high-temperature absorption chamber and a heating chamber. The absorbed laser signal is collected from the high-temperature chamber. Samples are heated in the chamber, and the gas produced during the decomposition process is collected. Second, the DFG-TDLAS output laser is employed to measure the absorption spectra of seven hydrocarbon molecules, including C1-C4 hydrocarbons and benzene. Standard hydrocarbon gases are measured at different temperatures and volume fractions to establish the absorption spectra database. The coal is heated to 623 K in the heating chamber, and the resulting gases from thermal decomposition are measured in the high-temperature chamber. The DFG-TDLAS system and hydrocarbon absorption spectra databases are used for qualitative analysis. Results and Discussions During the detection of standard hydrocarbon gases, the pressure in the high-temperature absorption chamber is maintained at 0.1 MPa, and the detection temperatures are 298, 423, 523, 623, and 723 K (Fig. 3). Hydrocarbon gas absorption is also measured at different

关键词： Absorption spectroscopy

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Reversible V4+/V5+ Redox in Na4vfe(Po4)3 Cathode for High-power Sodium-Ion Batteries

SSRN

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SSRN 2025年

作者： Xie, Peng-Xing Zhao, Qing-Yuan Dong, Haojie Long, Tao Ding, Meng-Sha Xie, Bin Wang, Xiaofeng Ling, Wei Liu, Mengting Wu, Xiongwei Wang, Peng-Fei Zeng, Xianxiang School of Chemistry and Materials Science Hunan Agricultural University Changsha410128 China Center of Nanomaterials for Renewable Energy State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical Engineering Xi'an Jiaotong University Shaanxi Xi’an710049 China Key Laboratory of Physics and Technology for Advanced Batteries Ministry of Education College of Physics Electron Microscopy Center Jilin University Changchun130012 China Hunan Engineering Technology Research Center of Vanadium Flow Battery and Energy Storage System Hunan Changsha410036 China College of Chemistry and Chemical Engineering Hunan Normal University Hunan Changsha410081 China

Delivery of high energy density in polyanion compound-Na3V2(PO4)3 based on three-electron redox is still challenging because of their controversial multi-electron reaction mechanism and unsatisfactory electrochemical reversibility. Herein, the reversible V4+/V5+ redox (ca. 4.0 V) could be successfully activated in Na4VFe(PO4)3 cathode material through a Na-rich strategy, demonstrating a reversible specific capacity of 154.7 mAh g−1 at 0.1 C and 90.3 mAh g−1 after 800 cycles at 20 C, with 80% of the initial capacity retained. The entire electrochemical reaction undergoes a highly recoverable phase transition by in-situ X-ray diffraction. Impressively, the Na-rich strategy could not only allow Na2 site to be occupied to activate the V4+/V5+ redox pair confirmed by X-ray absorption near-edge structure spectroscopy, but also enable Na+ transportation across the generated vacancies rather than synergistic Na+ diffusion. Therefore, Na4VFe(PO4)3||hard carbon full batteries deliver a high specific capacity of 104.5 mAh g−1 and 90 mAh g−1 at 0.2 C and 5 C, respectively. This work provides rational design strategy of multi-electron transfer reaction in high-energy sodium-ion batteries. © 2025, The Authors. All rights reserved.

关键词： Sodium-ion batteries

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Direct numerical simulation of Taylor-Couette flow with vertical asymmetric rough walls

arXiv

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arXiv 2023年

作者： Xu, Fan Su, Jinghong Lan, Bin Zhao, Peng He, Yurong Sun, Chao Wang, Junwu School of Energy Science and Engineering Harbin Institute of Technology Harbin150001 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences P. O. Box 353 Beijing100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing100049 China Innovation Academy for Green Manufacture Chinese Academy of Sciences Beijing100190 China Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing100084 China Department of Engineering Mechanics School of Aerospace Engineering Tsinghua University Beijing100084 China

Direct numerical simulations are performed to explore the effects of the rotating direction of the vertically asymmetric rough wall on the transport properties of Taylor-Couette (TC) flow, up to a Taylor number of Ta = 2.39×107. It is shown that, compared to the smooth wall, the rough wall with vertical asymmetric strips can enhance the dimensionless torque Nuω. More importantly, at high Ta, clockwise rotation of the inner rough wall (where the fluid is sheared by the steeper slope side of the strips) results in a significantly greater torque enhancement compared to counter-clockwise rotation (where the fluid is sheared by the smaller slope side of the strips), due to the larger convective contribution to the angular velocity flux. However, the rotating direction has a negligible effect on the torque at low Ta. The larger torque enhancement caused by the clockwise rotation of the vertically asymmetric rough wall at high Ta is then explained by the stronger coupling between the rough wall and the bulk, attributed to the larger biased azimuthal velocity toward the rough wall at the mid-gap of the TC system, the increased turbulence intensity manifested by larger Reynolds stress and a thinner boundary layer, and the more significant contribution of the pressure force on the surface of the rough wall to the torque. Copyright © 2023, The Authors. All rights reserved.

关键词： Direct numerical simulation

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Rapid Prediction Models for Oil Temperature and Surrounding Environment Temperature Fields in Buried Hot Crude Oil Pipelines

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Journal of Pipeline Systems engineering and Practice 2025年第3期16卷

作者： Yan, Feng Xu, Jingyan Li, Qifu Zhou, Chaoqun Ji, Mingyang Gong, Junhua Xiang, Yue Chen, Yujie Han, Dongxu Wang, Peng Dept. of Storage and Transportation Technology Research PipeChina Research Institute of Science and Technology 4 Dongting 1st Rd. Binhai New Area Tianjin300450 China Project Management Center of Production and Operation Dept Northeast Company of PipeChina Hunnan District Liaoning Province Shenyang110000 China Dept. of Production and Operation Changqing Oil and Gas Transportation Branch of Northwest Company of PipeChina Xingqing District Yinchuan Ningxia750004 China School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing102617 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'An Jiaotong Univ Xi'an710049 China Dept. of Digital Twin for Energy and Power Systems Sichuan Energy Internet Research Institute Tsinghua Univ Sichuan610213 China

Wax-rich or high-viscosity crude oil requires heating for long-distance transportation in buried pipelines. Monitoring the temperature distributions and variations of both oil and surrounding environment is crucial to ensuring safety and economic efficiency. This study proposes two models for rapidly predicting the steady-state oil temperature and surrounding environment temperature fields based on the Fourier neural operator (FNO) network and U-shaped network (UNet), respectively. These models leverage numerical results as training data, incorporating boundary conditions and environment grid coordinates at the pipeline cross section as inputs to predict the temperature distributions of both oil and the surrounding environment along the buried pipeline. With optimized hyperparameters, the models achieve accurate and efficient predictions. The FNO and UNet models had average RMS errors (RMSEs) in environment temperature field prediction of 2.68×10-3 and 5.49×10-3 at the pipeline cross section, respectively. For oil temperature predictions, the FNO model had an average relative error of 1.49×10-4, compared with 2.55×10-4 for the UNet model, with average absolute error values of 5.32×10-3 and 7.24×10-3, respectively. Moreover, both models exhibited strong generalization, with an average RMSE in the environment temperature field prediction of less than 3.5×10-2 and an average relative error in oil temperature predictions of less than 2.1×10-3 across different data sets. Comparatively, the FNO and UNet model had slightly higher prediction accuracy than the UNet model. In terms of computational efficiency for a 100-km pipeline, these models offer improvements of at least 116.25× over the numerical simulation method, with a maximum improvement of 1,775.03× as the number of simultaneously predicted pipeline cross sections increases. © 2025 American Society of Civil Engineers.

关键词： flowlines

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Navigating the Dual Pathways of Ion Removal in flow-Electrode Capacitive Deionization: Capacitive Trapping vs. Electrodialytic Migration

SSRN

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SSRN 2025年

作者： Gu, Haibo Hou, Chengsi Mao, Yunfeng Wu, Deli School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science & Engineering Tongji University Shanghai200092 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China Shanghai Institute of Pollution Control and Ecological Security Shanghai200092 China

By introducing flowing electrodes, FCDI enables desalination through dual mechanisms of electrodialytic and capacitive effects. Clarifying their distinct roles is essential to advance tailored system design and performance enhancement. This work elucidates the antagonistic interplay between capacitive trapping and electrodialytic migration in flow-electrode capacitive deionization (FCDI) through both electrochemical characterization and multiphysics modeling. Experimental analyses reveal that elevated flow rates enhance electrodialytic migration but impair capacitive adsorption. Multivariate parametric studies demonstrate that capacitive dominance prevails at high current densities and low electrolyte concentrations, whereas electrodialytic effects peak under high electrolyte concentration and moderate flow rates. The balance between the effects of electrodialysis (ED) and capacitive deionization (CDI) is greatly impacted by convective mass transfer, which is caused by the electrode flow rate. While higher solid weight percentages in the flow electrode improve the CDI effect by increasing the number of active sites for salt adsorption, increased electrode flow rates maximize the ED effect by encouraging ion transport in the electrolyte. In short words, strategies to promote free ions dispersing in the electrolyte would enhance the electrodialytic contribution, whereas the concentration polarization would benefit the capacitive contribution. This work opens the door for the exploration of upgrading FCDI architectures and optimizing operation parameters while providing insights into the intricate interactions within the system. © 2025, The Authors. All rights reserved.

关键词： Desalination

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Efficient Water Reforming of Biomass to H2via Well-Organized Redox-Neutral Cleavage of C−C, O−H and C−H Bonds

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Angewandte Chemie 2024年第4期137卷

作者： Wen-Min Zhang Prof. Yang Li State Key Laboratory of Multi-phase Flow in Power Engineering and Frontier Institute of Science and Technology Xi'an Jiaotong University Xi'an 712046 China

Hydrogen (H 2 ) is a clean and environmentally friendly energy carrier. The depletion of fossil fuels makes renewable H 2 production highly desirable. Water reforming of renewable biomass to hydrogen, with a relay of natural photosynthesis to biomass, would be an indirect pathway to realize the ideal but extremely challenging photocatalytic overall water splitting to hydrogen, with favorable thermodynamics. Since the seminal work of water reforming of biomass in 1980, great endeavors have been made. Nevertheless, hitherto, the entire kinetic pathway has been elusive, which seriously limits the reforming processes. Using a designed well-organized redox-neutral cleavage of C−C, O−H and C−H bonds enabled by photoelectrocatalysis, here, we show the efficient water reforming of biomass to hydrogen at room temperature, with a yield up to 93 %. The clear insights into the kinetic pathway with oxidation of carbon radicals to carbon cations as the indicated rate-determining step, would cast brightness for efficient and sustainable hydrogen production to accelerate the hydrogen economy.

关键词： hydrogen production biomass reforming photoelectrocatalysis iron catalysis redox-neutral chemical bonds cleavage

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Degradation of polyethylene terephthalate (PET) and polypropylene (PP) plastics in seawater

DeCarbon

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DeCarbon 2023年 1卷

作者： Meixin Guan Hui Jin Wenwen Wei Mi Yan State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF) Xi'an Jiaotong University 28 Xianning West Road Xi'an 710049 Shaanxi China State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 Zhejiang China

The world's marine litter consists mainly of plastic, and 99% of it does not float on the surface of the sea but on the seabed. The plastic carbon footprint necessarily includes the extraction or manufacture of raw materials, the conversion process, the distribution of products, the consumption of specific types of products and the disposal of the final product, as all these stages release carbon into the atmosphere. This work, inspired by marine microplastics and investigates how plastic waste is degraded and transformed in high-pressure, low-temperature seawater, this paper investigates the corrosion of polyethylene terephthalate (PET) and polypropylene (PP) plastics in seawater at high-pressure, using artificial seawater temperatures to simulate ocean temperatures of approximately 4 °C and time settings of 1 day–7 days. The results show that increasing the time enhances the degradation of the plastics and that changing the pressure has little effect on the degradation effect. Understanding its degradation in seawater can help us to better treat plastic waste and thus reduce the carbon footprint of the disposal process.

关键词： PET PP High-pressure seawater Degradation

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Atomically Dispersed Co Sites on BiOCl Nanosheets for Efficient CO 2 Photoreduction

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Green Energy & Environment 2025年

作者： Ting Peng Yiduo Wang Ke Wang Kaini Zhang Yiqing Wang Yufei Xu Qingqing Guan Guofu Wang Wenjie Zhang Binglan Wu Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710049 China College of Chemical and Biological Engineering Zhejiang University Hangzhou 310058 China Institute of Zhejiang University-Quzhou Quzhou 324000 China

Efficient CO 2 photoreduction to produce fuel remains a great challenge, due to the fast recombination of photogenerated charge carriers and the lack of effective reactive sites in the developed photocatalysts. Herein, single Co atoms (Co SA ) were highly dispersed on hydrothermally synthesized BiOCl nanosheets (BOC) by a facile two-step electrostatic self-assembly and pyrolysis method. The obtained Co SA -BOC could be performed for efficient CO 2 photoreduction to stoichiometrically produce CO and O 2 at the ratio of 2:1, with the CO evolution rate reaching 45.93 μmol g –1 h –1 , ∼4 times that of the pristine BOC. This distinctly improved photocatalytic performance for Co SA -BOC should be benefited from the introduction of atomically dispersed Co-O 4 coordination structures, which could accelerate the migration of photogenerated charge carriers to surface by creating an impurity energy level in the forbidden band, and act as the reactive sites to deliver the photogenerated electrons to activate CO 2 molecules for CO production. This work provides a facile and reliable strategy to highly disperse single atoms on low-dimensional semiconductors for efficient CO 2 photoreduction to selectively produce CO.

关键词： photocatalysis CO 2 reduction BiOCl nanosheets single Co atoms

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Study on the heat and mass transfer characteristics of wet air in metal foam in the space station environment

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Applied Thermal engineering 2025年

作者： Guowei Zhu Liang Zhang Yujuan Xia Hantao Zhou School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Key Laboratory of Multiphase Flow and Heat Transfer in Shanghai Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China China National Institute of Standardization Beijing 100191 China

This paper has developed a novel dehumidification device for space station environment, which uses foam copper as the core, with a Stirling refrigerator providing cooling, heat pipes assisting in heat conduction and a siphon water guidance system employed to remove condensate. Experiments on dehumidifying wet air within the foam copper were then carried out under simulated microgravity dehumidification conditions. The experimental conditions included different inlet air temperatures, humidities, air velocities, and cold end temperatures of the Stirling refrigerator. The experimental research indicates that as the inlet air temperature rises from 20 °C to 30 °C, the mass transfer coefficient increases by 57.06 %, and the sensible heat coefficient rises by 10.62 %. When the air velocity increases from 0.4 m·s −1 to 1.4 m·s −1 , these two coefficients increase by 111.79 % and 170.83 %, respectively. In contrast, increasing the relative humidity from 50 % to 80 % results in a 34.09 % decrease in the sensible heat coefficient, while the mass transfer coefficient increases by 11.4 %. When the cold-end temperature rises from 8 °C to 13 °C, the sensible heat transfer and mass transfer coefficients increase by 9.63 % and 4.06 %, respectively. Based on this, a sensitivity analysis was conducted using the experimental data, and heat and mass transfer correlations were fitted. The mean standard deviations of the heat and mass transfer correlations are 3.74 % and 6.30 %, respectively, indicating a high degree of fitting accuracy. This work provides a new humidity control solution for future space station thermal management systems.

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