检索结果-内蒙古大学图书馆

ASME 2024 Power Conference, POWER 2024

作者： Fan, Mengyang Zhao, Yongliang Liu, Ming Wang, Chaoyang Wang, Zhu Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

ISBN: (纸本)9780791888186

To achieve the net-zero emissions targets, the global share of renewable energy is rapidly increasing. The high penetration of intermittent and variable renewable power necessitates that coal-fired power plants enhance their operational flexibility for peak shaving and frequency regulation. Frequent and rapid start-ups, shutdowns, and peak shaving processes pose significant safety challenges to the steam turbine rotors. This paper investigates the impact of flexible operation on rotor stress. Firstly, an online monitoring model was developed and verified using a finite element model of a steam turbine high-medium pressure rotor. Secondly, the online calculation model was integrated with a dynamic coal-fired unit model developed using the JTopmeret software on the GSE platform, a well-established dynamic simulation tool for nuclear and fossil fuel power plants. Finally, a rotor low-cycle fatigue life assessment model was developed, and the von Mises stress and fatigue life loss under various load variation rates and ranges were determined. As the load variation rate increases, the life loss increases significantly, with maximum von Mises stress amplitudes of 5.2, 6.5 and 7.8 MPa at 1%, 2% and 3% Pe min−1 load variation rates, respectively. Conversely, as the load variation range increases, the life loss decreases substantially, with maximum von Mises stress amplitudes of 9.2 and 5.0 MPa during load variation processes of 50%-75% and 75%-100% THA, respectively. This study provides detailed guidance for optimizing the safe operation and control strategies of coal-fired power plants. Copyright © 2024 by ASME.

关键词： Steam turbines

来源：评论

学校读者我要写书评

暂无评论

THE FLEXIBILITY ENHANCEMENT OF SUBCRITICAL COAL-FIRED POWER PLANTS: CONTROL STRATEGY OPTIMIZATION FOR LIVE AND REHEAT STEAM TEMPERATURE

THE FLEXIBILITY ENHANCEMENT OF SUBCRITICAL COAL-FIRED POWER ...

引用

ASME 2024 Power Conference, POWER 2024

作者： Chen, Chen Liu, Ming Wang, Chaoyang Zhao, Yongliang Yan, Hui Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (纸本)9780791888186

With the increasing penetration of renewable power, flexible power sources are urgently required by the power grid to balance the supply and demand sides. Therefore, the operational flexibility of subcritical coal-fired power plants should be further enhanced. In this study, dynamic models of a reference 330MW subcritical coal-fired power plant were developed and validated. The load ramp performances of the reference plant were simulated. The maximum ramp rates during loading down processes were 2%Pe/min and 1.5%Pe/min in 75% -50% and 50% -40% load cycling ranges, respectively, and the maximum ramp rate during loading up processes is 1.5%Pe/min. That the live steam and reheat steam temperatures exceeding their thresholds limits for the load ramp rates. The subcritical power unit has a steam drum, serving as a substance and energy storage device, and allows partial decoupling of feedwater flow and coal flow. Consequently, an enhanced steam temperature control strategy, facilitated by adjusting the feedwater flow rate during the load ramp processes, was proposed. The feedwater flow rate is appropriately regulated during load cycling dynamic processes to assist the control of live steam and reheat steam temperatures. The models to obtain the live steam and reheat steam temperature variations influenced by the feedwater flow rates are developed, and implemented in the control strategy. Then, simulations on the reference power plant with the enhanced control strategy were conducted, and the temperature overshoots have been effectively suppressed. As a result, the load ramp rate is increased. For example, in the load cycling range of 75%-40%, the overall unit ramp rate is increased by 1%Pe/min, achieving an enhancement in the operational flexibility of subcritical units. Copyright © 2024 by ASME.

关键词： Coal

来源：评论

学校读者我要写书评

暂无评论

Effect of Particle Orientation on Heat Transfer in Arrays of Prolate Particles

引用

Computer Modeling in engineering & Sciences 2023年第8期136卷 1509-1526页

作者： Romana Basit Xinyang Li Zheqing Huang Qiang Zhou School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’anChina State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’anChina

Direct Numerical Simulations have been carried out to study the forced convection heat transfer of flow through fixed prolate particles for a variety of aspect ratios ar={5/4,5/3,5/1}with Reynolds number(Re)up to *** variations of the solid volume fraction c={0.1,0.2,0.3}with four Hermans orientation factors S={−0.5,0,0.5,1}are *** has been found that changes in S cause prominent variations in the Nusselt *** general,Nusselt number increases with the decrease of *** all three aspect ratios,the Nusselt number remains a linear function of S at different c and ***,it is concluded that,for heat transfer from prolate muti-particle system,the effects of orientations cannot be ignored.A new correlation for Nusselt number has been developed for arrays of prolate particles using the simulation data as a function of Re,c,S and ar.

关键词： Direct Numerical Simulation heat transfer lattice Boltzmann method particle orientations prolate particles

来源：评论

学校读者我要写书评

暂无评论

Particle convective heat transfer near the wall in a supercritical water fluidized bed by single particle model coupled with CFD-DEM

引用

Particuology 2023年第2期73卷 47-58页

作者： Tianning Zhang Zhen Wan Youjun Lu State Key Laboratory of Multiphase Flow in Power Engineering(SKLMFPE) Xi'an Jiaotong UniversityXi'an710049ShaanxiChina Xi'an Electronic Engineering Research Institute Xi'an710100ShaanxiChina

Supercritical water fluidized bed(SCWFB)is a promising reactor to gasify biomass or *** optimization design is closely related to wall-to-bed heat transfer,where particle convective heat transfer plays an important *** paper evaluates the particle convective heat transfer coefficient(h_(pc))at the wall in SCWFB using the single particle *** critical parameters in the single particle model which is difficult to get experimentally are obtained by the computational fluid dynamics-discrete element method(CFD-DEM).The contact statistics related to particle-to-wall heat transfer,such as contact number and contact distance,are also *** results show that particle residence time(τ),as the key parameter to evaluate h_(pc),is found to decrease with rising velocity,while increase with larger thermal boundary layer thickness.τfollows a gamma function initially adopted in the gas-solid fluidized bed,making it possible to evaluate h_(pc) in SCWFB by a simplified single particle *** theoretical predicted h_(pc) tends to increase with rising thermal gradient thickness at a lower velocity(1.5 U_(mf)),while first decreases and then increases at higher velocity(1.75 and 2 U_(mf)).h_(pc) occupies 30%-57%of the overall wall-to-bed heat transfer coefficient for a particle diameter of 0.25 *** results are helpful to predict the overall wall-to-bed heat transfer coefficient in SCWFB combined with a reasonable fluid convective heat transfer model from a theoretical perspective.

关键词： Supercritical water Fluidized bed Particle residence time Discrete element method Single particle model

来源：评论

学校读者我要写书评

暂无评论

Review of spatial scale dispersion models (ATDMs) to simulate environmental dispersion and deposition of radionuclides and the overview of GIS coupling with dispersion models

引用

International Journal of Advanced Nuclear Reactor Design and Technology 2024年第4期6卷 256-280页

作者： Muhammad, Hussaini Xuan, Wang Wang, Mingjun Su, Guanghui School of Nuclear Science and Technology Shanxi Key Laboratory of Advanced Nuclear Energy and Technology State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Abuja Nigeria

Estimation of the radiological consequences including the calculation of radiation doses to the exposed population requires numerical evaluation of atmospheric radioactive releases from nuclear facilities under accidental scenarios for implementation of adequate protective and other response actions to prevent or minimize severe deterministic effects and reduce the probability of occurrence of stochastic effects. This paper reviews various state-of-the-art spatial scale atmospheric dispersion models, known as the ATDMs, designed to evaluate atmospheric transport, dispersion, and depositions of radionuclide emissions from release sources. The ATDMs (atmospheric transport, dispersion, and deposition models) reviewed in this paper are FLEXPART, CALPUFF, LADAS, RASCAL, RIMPUFF, and HotSpot. These ATDMs are increasingly applied to perform probabilistic radiological risk assessment, which is one of the IAEA safety requirements for site evaluation of new NPP, and the calculated doses can be used to establish EPZs, an underlying basis of emergency preparedness. The numerical approaches, modeling methodology, advantages, limitations, scope of applications, and research investigations performed using these models in radiological and other environmental impact assessments within their scope of applications are presented. GIS has been widely recognized as a technique applied to aid the modeling of pollutant dispersion and visualization of model outputs in a spatial context, among other benefits. In nuclear accident consequence evaluation, spatial data provides key information such as accident location, range of radiological contamination, population density, etc, which are very important. This demonstrates the high significance of GIS-ATDMs coupling. Therefore, an overview of the coupling of dispersion models with GIS is also highlighted. © 2025 Xi'an Jiaotong University

关键词： Risk assessment

来源：评论

学校读者我要写书评

暂无评论

Modulating redox transition kinetics by anion regulation in Ni-Fe-X(X=O,S,Se,N,and P)electrocatalyst for efficient water oxidation

引用

Nano Research 2024年第6期17卷 4720-4728页

作者： Liting Wei Kaini Zhang Rui Zhao Lei Zhang Yan Zhang Suyi Yang Jinzhan Su International Research Center for Renewable Energy&State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Applied Chemistry Yuncheng UniversityYuncheng 044000China

NiFe-based electrocatalysts will experience dynamical surface reconstruction during oxygen evolution reaction(OER)process,and the derived metal(oxy)hydroxide hybrids on the surface have been considered as the actual active species for *** efforts have been dedicated to understanding the surface reconstruction,but there is rare research on recognizing the origin of improved performance derived from anion species of ***,the OER electrocatalytic characteristics were tuned with different anions in NiFe-based catalyst,using NiFe-based oxides/nitride/sulfide/selenides/phosphides(NiFeX,X=O,N,S,Se,and P)as the model *** combination of X-ray photoelectronic spectroscopy,electrochemical tests,operando spectroscopic characterizations,and density functional theory(DFT)calculations,reveals that anion with lower electronegativity in NiFe-based catalyst leads to higher conductivity and delayed valence transition of Ni sites,as well as optimized adsorption behavior towards oxygen intermediates,contributing to enhanced OER ***,NiFeP electrocatalyst demonstrates an ultralow overpotential of 265 mV at 20 mA·cm−2 for OER,as well as long-term *** work not only offers further insights into the effect of anionic electronegativity on the intrinsic OER electrocatalytic properties of NiFe-based electrocatalyst but also provides guide to design efficient non-noble metal-based electrocatalysts for water oxidation.

关键词： oxygen evolution reaction(OER) anion species electronegativity valence transition

来源：评论

学校读者我要写书评

暂无评论

Effect of introducing oxygen into ethylene tar pitches on their carbonaceous products

引用

Chinese Journal of Chemical engineering 2024年第12期76卷 135-146页

作者： Rongqi Chen Yongzheng Zhang Yanli Wang Chunyin Shen Liang Zhan Licheng Ling State Key Laboratory of Green Chemical Engineering and Industrial Catalysis Key Laboratory of Specially Functional Polymeric Materials and Related Technology(Ministry of Education)Shanghai Key Laboratory of Multiphase Materials Chemical EngineeringState Key Laboratory of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Ethylene tar is a prospective precursor for preparing carbonaceous materials,which is regarded as a representative soft carbon material after ***,the introduction of oxygen can influence the morphology of the final carbonaceous *** the introduction of oxygen,dealkylation and dehydrogenation will be promoted and the molecules can be linked more *** the subsequent carbonization,the biphenyl structures caused by the deoxygenation via the elimination of CO_(2),as well as the reserved aromatic ether bonds,can facilitate the strong cross-linking,which will restrain the movement of the carbon layers and the formation of the graphitic *** the graphitization treatment at 2800℃,the oxidized pitch can lead to short-range ordered and long-range unordered structures,while the sample without oxidation can result in long-range ordered graphitic *** can be proved that a simple oxidation-carbonization treatment can transform ethylene tar into hard carbon structures.

关键词： Fuel Oxidation Ethylene tar pitch Carbonization Hard carbon Chemical processes

来源：评论

学校读者我要写书评

暂无评论

Electrospinning engineering of gas electrodes for high-performance lithium-gas batteries

引用

Carbon Energy 2024年第10期6卷 353-398页

作者： Jingzhao Wang Xin Chen Jianan Wang Xiangming Cui Ze Wang Guangpeng Zhang Wei Lyu Maxim Shkunov S.Ravi P.Silva Yaozu Liao Kai Yang Wei Yan State Key Laboratory of Multiphase Flow in Power Engineering Department of Environmental Science and EngineeringSchool of Energy and Power EngineeringXi'an Jiaotong UniversityXi'anChina Advanced Technology Institute University of SurreyGuildfordSurreyUK State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghaiChina

Lithium-gas batteries(LGBs)have garnered significant attention due to their impressive high-energy densities and unique gas conversion ***,the practical application of LGBs faces substantial challenges,including sluggish gas conversion kinetics inducing in low-rate performance and high overpotential,along with limited electrochemical reversibility leading to poor cycle *** imperative task is to develop gas electrodes with remarkable catalytic activity,abundant active sites,and exceptional electrochemical ***,a versatile and well-established technique for fabricating fibrous nanomaterials,has been extensively explored in LGB *** this work,we emphasize the critical structure-property for ideal gas electrodes and summarize the advancement of employing electrospun nanofibers(NFs)for performance enhancement in *** elucidating the fundamental principles of LGBs and the electrospinning technique,we focus on the systematic design of electrospun NF-based gas electrodes regarding optimal structural fabrication,catalyst handling and activation,and catalytic site optimization,as well as considerations for large-scale *** demonstrated principles and regulations for electrode design are expected to inspire broad applications in catalyst-based energy applications.

关键词： carbon nanofibers electrocatalyst electrospinning gas electrodes metal-gas batteries

来源：评论

学校读者我要写书评

暂无评论

Polyacrylate modified Cu electrode for selective electrochemical CO_(2) reduction towards multicarbon products

引用

Science Bulletin 2024年第15期69卷 2395-2404页

作者： Yuchuan Shi Kaini Zhang Chung-Li Dong Ta Thi Thuy Nga Miao Wang Daixing Wei Jialin Wang Yiqing Wang Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China Department of Physics Tamkang UniversityNew Taipei City 25137China

Highly selective production of value-added multicarbon(C^(2+))products via electrochemical CO_(2) reduction reaction(eCO_(2)RR)on polycrystalline copper(Cu)remains ***,the facile surface modification using poly(α-ethyl cyanoacrylate)(PECA)is presented to greatly enhance the C^(2+)selectivity for eCO_(2)RR over polycrystalline Cu,with Faradaic efficiency(FE)towards C^(2+)products increased from30.1%for the Cu electrode to 72.6%for the obtained Cu-PECA electrode at-1.1 V *** hydrogen electrode(RHE).Given the well-determined FEs towards C^(2+)products,the partial current densities for C^(2+)production could be estimated to be-145.4 mA cm~(-2)for the Cu-PECA electrode at-0.9 V *** in a homemade flow ***-situ spectral characterizations and theoretical calculations reveal that PECA featured with electron-accepting-C≡N and-COOR groups decorated onto the Cu electrode could inhibit the adsorption of^(*)H intermediates and stabilize the^(*)CO intermediates,given the redistributed interfacial electron density and the raised energy level of d-band center(E_(d))of Cu active sites,thus facilitating the C-C coupling and then the C^(2+)selective *** study is believed to be guidable to the modification of electrocatalysts and electrodes with polymers to steer the surface adsorption behaviors of reaction intermediates to realize practical eCO_(2)RR towards value-added C^(2+)products with high activity and selectivity.

关键词： Electrochemical CO_(2)reduction Polymer modification Electron transfer C_(2+)products

来源：评论

学校读者我要写书评

暂无评论

Numerical investigations on cluster characteristics in the supercritical water circulating fluidized bed riser

引用

Particuology 2024年第11期94卷 281-293页

作者： Kenan Xi Runqing Li Xiazhi Li Mei Li Xiudong Xu Yu Zhang Hao Wang Youjun Lu Northwest Institute of Nuclear Technology Xi'an710024China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an710049China Xi'an Institute of Applied Optics Xi'an710065China

There are currently no reports about clusters in the supercritical water circulating fluidized bed(SCWCFB).Simulations were conducted to investigate the numbers,diameters,aspect ratios,circularity,and orientation angles of cluster in the riser of SCWCFB via two-fluid model across different flow velocities,solid circulation rates,pressures,and *** results show that cluster numbers are mainly between 10 and 80 per *** are more at the bottom but less at the top,and more near the wall but less at the *** diameters are mainly between 0.2 and 0.5 times the bed *** are large at the bottom but small at the top,and large at the center but small near the *** aspect ratios are mainly between 0 and 1,indicating that most clusters have shorter width than their ***-like clusters are more likely to appear near the walls,and clusters at the center of the riser are more likely to be *** circularity is mainly between 0.2 and 0.4,suggesting that the shapes of clusters are far from the *** absolute values of cluster orientation angles are mainly between 75°and 90°,indicating that most clusters move in the vertical *** fluid velocities may facilitate cluster coalescence.

关键词： Supercritical water Circulating fluidized bed Cluster Two-fluid model Riser

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：