检索结果-内蒙古大学图书馆

ASME 2024 International Mechanical engineering Congress and Exposition, IMECE 2024

作者： Yang, Dong An, Ning Du, Xiaocheng Han, Lei Guo, Zerui Wei, Ziyu State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Shaanxi Xi'an China

ISBN: (纸本)9780791888667

When the boiler load varies, the operational parameters in the water wall will change, this process is called as dynamic process. Dynamic process presents unique flow and heat transfer phenomena within the water wall. To investigate the process, the research was conducted in a vertical upward smooth tube for a supercritical circulating fluidized bed (CFB) boiler. Experiments were conducted to explore the dynamic characteristics during transcritical pressure process. The results indicate that as system pressure decreases from 23 MPa to 21 MPa, the mass flux within the tube increases sharply, and the outlet fluid temperature decreases. Concurrently, a rapid rise in wall temperature was observed. As the inlet mass flux increases, the wall temperature eventually returns to the normal value. The dynamic heat transfer coefficients were calculated throughout the transcritical pressure process, revealing stages of heat transfer deterioration, subcooled boiling, and single-phase water heat transfer. In addition, experiments and numerical simulations were carried out to explore the dynamic characteristics at supercritical pressure. The dynamic response curves during the step process of heat flux and inlet enthalpy under supercritical pressure conditions were obtained. As the inlet enthalpy decreases, the system mass flux increases, and as the heat flux increases, the system mass flux decreases. And there is no rise in wall temperature during the dynamic response at supercritical pressure. Copyright © 2024 by ASME.

关键词： Water tube boilers

来源：评论

学校读者我要写书评

暂无评论

Thermal-diffusive instabilities of laminar premixed CH4/H2/air flat flames 10

Thermal-diffusive instabilities of laminar premixed CH4/H2/a...

引用

10th Asia-Pacific Conference on Combustion, ASPACC 2015

作者： Jin, Wu Wang, Jinhua Yu, Senbin Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

As one of the most promising clean alternative fuels, natural gas has been widely used in automobile engines. However, due to the slow burning velocity of natural gas and its poor lean-burn ability, hydrogen is often added to improve its combustion behavior. Researches on the fundamental laminar premixed flame characteristics of CH4/H2 blends are of great significance to understand the combustion process in practical combustors. The intrinsic instability of laminar flame is one of the classic issues in flame dynamics, which presents the dynamic response of laminar premixed flamelets to weak perturbations. By studying dynamic mechanism of intrinsic instability, we can estimate the burning velocity more accurately and gain a deeper insight into the turbulent combustion process in spark ignition engines. In this study, the cellular instabilities of laminar premixed CH4/H2/air flat flames were studied using McKenna burner with OH-PLIF technique. It was found that the addition of H2 can broaden the lean combustion limit on flat flame burner with which the cellular instabilities were brought. The digital and OH-PLIF images were obtained to calculate the quantitative parameters of cellular length scale, which is associated with the properties of fuel mixtures such as Lewis number, Markstein number et al. Through the theoretic analysis, we make a thorough investigation on the mechanism about how the cellular scales were determined.

关键词： Natural gas

来源：评论

学校读者我要写书评

暂无评论

Angle Scattering Method for Soot Concentration Measurement under Ultra-Low Emissions Condition

引用

Energy engineering 2022年第2期119卷 511-522页

作者： Bin Yang Xingchen Zhu Jie Deng Xiaoxu Guo Jinke Han Xiaowei Liu School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai200093China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan430074China

Aiming at the problem of soot concentration measurement under ultra-low emission conditions,a forward small angle soot concentration measurement method is *** a typical boiler emission of 0.1μm-3.0μm bimodal distribution soot as an object,the particle scatter simulation calculation under different parameters is carried out,and the influence of detection angle and particle size on the angular scatteringmeasurement of ultra-low emission soot is *** influence of detection angle and particle size on the angular scatteringmeasurement of ultra-lowemission soot is ***,thewavelength of incident light is 650 nm,and the forward detection angle parameter is 15◦for the design of forward small angle soot concentration measurement *** experimental system for measuring soot with standard concentration is *** of particle concentration measurement of 1.0μm and 3.0μm under ultra-low emission conditions are carried *** results show that the average deviation of soot concentration measurement is less than 0.10 mg/m3 under the condition of ultra-low emission by using 15◦of forward detection,which provides an effective way for monitoring ultra-low emission soot concentration in coal-fired power plants.

关键词： Emission monitoring ultra-low emission soot concentration angular scattering

来源：评论

学校读者我要写书评

暂无评论

Numerical Stability and Accuracy of Contact Angle Schemes in Pseudopotential Lattice Boltzmann Model for Simulating Static Wetting and Dynamic Wetting

引用

Computer Modeling in engineering & Sciences 2023年第10期137卷 299-318页

作者： Dongmin Wang Gaoshuai Lin Key Laboratory of Multiphase Flow and Heat Transfer in Shanghai Power Engineering School of Energy and Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai200093China Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application Suzhou University of Science and TechnologySuzhou215009China

There are five most widely used contact angle schemes in the pseudopotential lattice Boltzmann(LB)model for simulating the wetting phenomenon:The pseudopotential-based scheme(PB scheme),the improved virtualdensity scheme(IVD scheme),the modified pseudopotential-based scheme with a ghost fluid layer constructed by using the fluid layer density above the wall(MPB-C scheme),the modified pseudopotential-based scheme with a ghost fluid layer constructed by using the weighted average density of surrounding fluid nodes(MPB-W scheme)and the geometric formulation scheme(GF scheme).But the numerical stability and accuracy of the schemes for wetting simulation remain unclear in the *** this paper,the numerical stability and accuracy of these schemes are clarified for the first time,by applying the five widely used contact angle schemes to simulate a two-dimensional(2D)sessile droplet on wall and capillary imbibition in a 2D channel as the examples of static wetting and dynamic wetting simulations respectively.(i)It is shown that the simulated contact angles by the GF scheme are consistent at different density ratios for the same prescribed contact angle,but the simulated contact angles by the PB scheme,IVD scheme,MPB-C scheme and MPB-W scheme change with density ratios for the same fluid-solid interaction *** PB scheme is found to be the most unstable scheme for simulating static wetting at increased density ratios.(ii)Although the spurious velocity increases with the increased liquid/vapor density ratio for all the contact angle schemes,the magnitude of the spurious velocity in the PB scheme,IVD scheme and GF scheme are smaller than that in the MPB-C scheme and MPB-W scheme.(iii)The fluid density variation near the wall in the PB scheme is the most significant,and the variation can be diminished in the IVD scheme,MPB-C scheme *** variation totally disappeared in the GF scheme.(iv)For the simulation of capillary imbibition,the MPB-C scheme,MPB-Wschem

关键词： Pseudopotential lattice Boltzmann model contact angle scheme static wetting dynamic wetting capillary imbibition

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of the static performance of an annular aerostatic gas thrust bearing applied in the cryogenic turbo-expander of the EAST subsystem

引用

Plasma Science and Technology 2017年第2期19卷 115-122页

作者： Tianwei LAI Bao FU Shuangtao CHEN Qiyong ZHANG Yu HOU State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an 710049 People＇s Republic of China Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 People＇s Republic of China

The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust beating. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.

关键词： EAST helium cryogenic system aerostatic thrust beating inclination bearing load

来源：评论

学校读者我要写书评

暂无评论

Computational homogenization of thermomechanical properties for Fully Ceramic Microencapsulated fuel with 3D printed SiC matrix

引用

Annals of Nuclear Energy 2025年 222卷

作者： Yiwen Chen Qi Lu Changwen Liu Wei Li Dalin Zhang G.H. Su State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an 710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu 61213 China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong University Xi’an 710049 China

Fully Ceramic Microencapsulated (FCM) fuel, fabricated using 3D printing technology, incorporates traditional Tristructural-Isotropic (TRISO) fuel particles embedded within a 3D-printed SiC matrix. This fuel type shows great potential for compact, high-temperature nuclear reactors. However, comprehensive performance analysis remains challenging due to the multilayered structure, complex material properties, and the irradiation behavior of numerous TRISO particles within the matrix. To address these challenges, this study aims to apply finite element (FE)-based computational homogenization to evaluate the fuel’s thermomechanical properties. First, a detailed finite element analysis (FEA) of a single TRISO particle’s performance was conducted, focusing primarily on the Buffer-IPyC gap size change during irradiation, a critical factor influencing the fuel’s thermal performance. Second, the homogenization of a single TRISO particle was performed using FEA, accounting for the changes in the Buffer-IPyC gap size. Finally, homogenized TRISO particles were randomly distributed and perfectly bonded within a 3D-printed SiC matrix to form a Representative Volume Element (RVE). The FE homogenization of the RVE was then conducted to derive the effective thermomechanical properties of the FCM fuel. The packing fraction of TRISO particles in the matrix ranged from 10 % to 50 %, with temperature and burnup conditions spanning 800–1600 K and 0–16 % FIMA, respectively. Results show that irradiation significantly affects the effective properties of the fuel, though this impact diminishes as burnup increases. Additionally, the effective thermal conductivity of the FCM fuel decreases with increasing TRISO packing fraction, assuming the thermal conductivity of the SiC matrix exceeds that of TRISO particles. This study provides a valuable reference for the design and optimization of FCM fuel for future nuclear applications.

关键词： Thermal conductivity of solids

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to “Numerical simulation of an externally heated fixed bed reactor for coal pyrolysis based on porous media” [Chem. Eng. Res. Des. 211 (2024) 137–151]

引用

Chemical engineering Research and Design 2025年 218卷 454-454页

作者： Haoyue Li Yuanpei Luo Fei Dai Jun Sui Hongguang Jin Laboratory of Distributed Energy Systems and Renewable Energy Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

来源：评论

学校读者我要写书评

暂无评论

An experimental study of premixed laminar methane/oxygen/argon flames doped with hydrogen at low pressure with synchrotron photoionization

引用

Chinese Science Bulletin 2008年第8期53卷 1262-1269页

作者： WANG JinHua HU ErJiana HUANG ZuoHua MA ZhiHao TIAN ZhenYu WANG Jina LI YuYana State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China

Laminar premixed stoichiometric methane/hydrogen/oxygen/argon flames were investigated with tun- able synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spec- trometry techniques. The methane/hydrogen fuel blends with hydrogen volumetric fraction of 0, 20%, 40%, 60% and 80% were studied. All observed flame species, including stable intermediates and radi- cals in the flames, were detected by measuring photoionization mass spectra and photoionization effi- ciency (PIE) spectra. Mole fraction profiles of major species and intermediates were derived by scan- ning burner at some selected photon energies near ionization thresholds. The influence of hydrogen addition on mole fraction of major species and intermediates was analyzed. The results show that the major species mole fraction of CO, CO2 and CH4 decreases with the increase of hydrogen fraction. The mole fraction of intermediates measured in this experiment decreases remarkably with the increase of hydrogen fraction. This would be due to the increase of H and OH radicals by hydrogen addition and the high diffusivity and activity of H radical promoting the chemical reaction. In addition, the increase of H/C ratio with the increase of hydrogen fraction also leads to the decrease of the mole fraction of car- bon-related intermediates and contributes to the decrease of unburned and incomplete combustion products.

关键词：甲烷氢混合火焰同步加速器 MBMS

来源：评论

学校读者我要写书评

暂无评论

An investigation on heat transfer to supercritical water in inclined upward smooth tubes

An investigation on heat transfer to supercritical water in ...

引用

作者： Yin, Fei Chen, Ting-Kuan Li, Hui-Xiong National Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China National Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Within the range of pressures from 23 to 30 MPa, mass velocities from 600 to 1200 kg/(m 2 s), and heat fluxes from 200 to 600 kW/m 2 , experiments have been performed for an investigation on heat transfer to supercritical water in inclined upward smooth tubes with an inner diameter of 26 mm and an inclined angle of 20° from the horizon. The results indicated that heat transfer characteristics of supercritical water are not uniform along the circumference of the inclined tube. An increase in the mass velocity of the working fluid can decrease and even eliminate the non-uniformity. Properties of supercritical fluid acutely vary with the temperature near the pseudocritical point. While the ratio of the mass velocity to the heat flux exceeded 2.16 kg/(kWs), heat transfer enhancement occurred near the pseudocritical point;conversely, heat transfer deterioration occurred while the ratio of the mass velocity to the heat flux was lower than 2.16 kg/(kWs). As the pressure increased far from the critical pressure, the amount of deterioration decreased. Correlations of heat transfer coefficients of the forced-convection heat transfer on the top and bottom of the tube have been provided, and can be used to predict heat transfer coefficient of spirally water wall in supercritical boilers.

关键词： Pipe flow

来源：评论

学校读者我要写书评

暂无评论

Multi-physics analysis of the galvanic corrosion of Mg-steel couple under the influence of time-dependent anisotropic deposition film

引用

Journal of Magnesium and Alloys 2021年第3期9卷 866-882页

作者： Kai Wang Chenpei Li Yanhui Li Jinling Lu Yueshe Wang Xingqi Luo State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi'an University of TechnologyNo.5 Jinhua South RoadXi'an 710048China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityNo.28 Xianning West RoadXi'an 710049China

The anisotropic deposit film formed during the galvanic corrosion can impede the mass transfer of the involved species,thereby affecting the electro-chemical behavior and the evolution of galvanic *** limitations of experimental studies in the spatial-temporal scales restrict a deeper understanding of the corrosion mechanism,which can be complemented by numerical simulation.A multi-physics coupled model is proposed in this work to systematically investigate the temporal and spatial evolution of galvanic corrosion of the Mg-steel couple with the growing anisotropic deposition *** utilizing the multi-physics field coupled technique,various coupled physical-chemical processes underlying the corrosion behavior are built into the model,including chemical reactions,ionic mass transfer in the bulk solution and the deposition layer,interfacial reaction,deposition of corrosion products as well as the morphological transitions caused by metal dissolution and *** particular,the anisotropic deposit film is considered to be a porous layer with a porosity varying in time and space as the corrosion *** predicted corrosion morphology by this model is better than the previous *** coupled relationship between the electrochemical behavior(e.g.,electrode reaction kinetics,current density,surface potential)and the physical processes(e.g.,ionic transport,geometric evolution of metal surface and film interface)is *** results indicate that a porous deposition layer with a denser inner layer and a loose outer layer is generated,leading to more significant inhibition of mass transfer in the inner layer than the outer *** anisotropism of the deposition layer results in a non-uniform conductivity distribution and a discontinuous current density distribution in the *** current density on the electrode surface is inhibited by the deposition layer and the variation in the cathode/anode area ratio during the corrosion *** c

关键词： Galvanic corrosion Corrosion product film Modeling Mass transport Porosity

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：