检索结果-内蒙古大学图书馆

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

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

Investigation on catalyzed reactivities of synthetic model coal under oxy-fuel conditions by thermal analysis

Investigation on catalyzed reactivities of synthetic model c...

引用

9th Asia-Pacific Conference on Combustion, ASPACC 201.

作者： Wang, Chang'an Du, Yongbo Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Oxy-fuel combustion is one of the near-zero emission clean coal technologies, which can realize large-scale CO2 capture. In this paper, catalyzed reactivities of synthetic model coal incorporating Fe 2O3, TiO2, and MnO2 under oxy-fuel conditions have been investigated using thermal analysis method. Experimental results show that all three catalysts present a certain extent catalytic action on the combustion behaviors of synthetic model coal under oxy-fuel conditions. The catalytic activity in main combustion process of model coal could be described as follows: Fe2O3 > TiO2 > MnO2. The increase of catalyst content causes the model coal combustion process to slightly shift to lower-temperature zone. The ignition temperature Ti shows almost no variation as Fe2O 3 or TiO2 is added into the samples. The catalysts present a not very obvious catalytic activity on the pyrolysis behaviors of synthetic model coal. In addition, TiO2 shows the greatest catalytic activity on the model coal gasification performance, while MnO2 plays an unfavorable role. The catalytic activity in gasification process of model coal could be described as follows: TiO2 > Fe2O3 > MnO2.

关键词： Coal

来源：评论

学校读者我要写书评

暂无评论

Experimental exploration of the effect of oxy-fuel combustion on ash deposition behavior of Zhundong high-alkali coal 7

Experimental exploration of the effect of oxy-fuel combustio...

引用

7th International Conference on power {1., ICOPE 201.

作者： Sun, Ruijin Wang, Chang'an Zhao, Lei Wang, Chaowei Han, Tao Zhu, Chenzhao Liu, Yinhe Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an710049 China

Zhundong coalfield has a super-large reserve of coal resources. However, its high-alkali feature deteriorates the phenomenon of ash deposition and slagging in coal-fired boilers. Oxy-fuel combustion is a clean and efficient combustion technology, which promotes the efficient and clean utilization of high-alkali coals. While the ash deposition behaviors of high-alkali coals in oxy-fuel case are still unclear. This study compared the differences in morphology and element distribution of ash deposits between air and oxy-fuel conditions to reveal the ash deposition characteristics and mineral migration during oxy-fuel combustion of high-alkali coals. Experimental results showed that the ash deposits were less compact with less floc ash adhering to the ash particles during oxy-fuel combustion compared to air case. Besides, few sulphur, sodium, chlorine and calcium existed in the ash deposits in oxy-fuel combustion, which was constant with the fewer and weaker diffraction peaks of sodium chloride, sodium sulphate, anorthite and mullite under oxy-fuel condition. With the oxygen concentration increased, the intensity of sodium chloride diffraction peak is stronger. © ICOPE 201. - 7th International Conference on power {1., Proceedings. All rights reserved.

关键词： Coal

来源：评论

学校读者我要写书评

暂无评论

ABO3-based photocatalysts for water splitting

引用

Progress in Natural Science:Materials International 2012年第6期22卷 592-615页

作者： Jinwen Shi Liejin Guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering(MFPE)Xi'an Jiaotong University(XJTU)28 West Xianning RoadXi'an

ABO3-based photocatalysts for water splitting were systematically reviewed in this manuscript. Crystal structure and chemical composition characteristics of ABO3materials were briefly introduced to guide the modification of ABOrbased *** ABO3-based photocatalysts were then reviewed in detail and divided into four groups based on the employed modification strategies,i.e.,chemical component adjustment,micro-/nano-structure adjustment,local lattice structure adjustment,and application of the modification strategy of ABO3photocatalysts in designing *** this section,the recent research works on ABOrbased photocatalysts in our group were ***, application of ABO3photocatalysts in Z-scheme systems for overall water splitting was *** review summarized the development of ABOrbased photoaitalysts and showed the values and possible direction of future research,thereby ottering a guide for photocatalytic water splitting.

关键词： Perovskite Band structures Micro-/nano-structures Local lattice structures Energy conversion Photochemistry

来源：评论

学校读者我要写书评

暂无评论

Uncertainty analysis of molten corium In-Vessel Retention under External Reactor Vessel Cooling

引用

International Journal of Advanced Nuclear Reactor Design and Technology 2023年第4期5卷 159-167页

作者： Wu, Shihao Wang, Dong Zhang, Yapei Zhou, Yukun Tian, Wenxi Qiu, Suizheng Su, G.H. School of Nuclear Science and Technology Shaanxi Engineering Research Center of Advanced Nuclear Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

External Reactor Vessel Cooling (ERVC) is a key measure to realize molten corium In-Vessel Retention (IVR). The uncertainty of severe accident in core leads to the uncertainty of molten pool parameters in lower head, which may threat the reliability of successful implementation of IVR. In this study, an uncertainty analysis is employed to ensure the reliability of ERVC technology to IVR with the final two-layer molten pool configuration of AP1.00.600 simulations are performed to determine the effect of five key parameters. As long as parameters are within high probability density range, lower head can remain intact, and safety margin is greater than 1. %. For influence level and correlation of parameters, the order on metal layer is: Decay heat > Fe mass > UO2 mass > Zr oxidation fraction > Emissivity of metal layer. The results can provide guidance for subsequent research direction and optimal design of mitigation measures. © 2024 Xi'an Jiaotong University

关键词： Uncertainty analysis

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation and structural optimization of spiral finned tube thermal energy storage

引用

International Journal of Advanced Nuclear Reactor Design and Technology 2023年第3期5卷 123-136页

作者： Ma, Yunfei Meng, Yu Li, Jingyu Chen, Weixiong Yang, Xiaohu Li, Shaodan Chong, Daotong Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Wuhan Second Ship Design and Research Institute Wuhan430205 China

Thermal energy storage (TES) has emerged as a promising solution to enhance nuclear safety by passively removing decay heat during reactor shutdown and accidents, thus preventing overheating of the reactor core and protecting the integrity of containment barriers. The research of TES with different structures has broad application prospects and practical significance. In this study, the melting process of phase change material (PCM) in various TES structures was simulated by the numerical simulation method in two and three dimensions. The mechanism of gravity-driven natural convection enhancing heat transfer was revealed. The effects of different TES structures, fin pitch, fin height, and fin thickness on heat transfer performance were studied. The results showed that many vortices formed by liquid PCM are the main reason for enhancing the natural convection. Adding fins could greatly accelerate the heat storage process. The melting time of PCM in annular and spiral finned tube TES was 47.3% and 61.3% less than that in smooth tube TES, respectively. In the present study, the heat transfer effect was enhanced as the spiral fin pitch became small, the fin height increased and the fin thickness increased. Two opposite effects of fin structure on the natural convection were revealed: (1. positive effect provided by heat transfer enhancement and (2) negative effect produced by blockage. © 2023 Xi'an Jiaotong University

关键词： Phase change materials

来源：评论

学校读者我要写书评

暂无评论

The evaporation of nanoscale sodium liquid film on the non-ideal nanostructure surface: A molecular dynamics study

引用

International Journal of Advanced Nuclear Reactor Design and Technology 2023年第1期5卷 1-8页

作者： Wang, Zetao Ye, Tianzhou Guo, Kailun Tian, Wenxi Qiu, Suizheng Su, Guanghui State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Lab of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an710049 China

The nanoscale liquid sodium film inside the microporous wick structure is of great importance to understanding the evaporation mechanism of the sodium heat pipe. The novel optimized wick structure is made of several layers of special screen. The surface of each screen exhibits a nanostructure type. Some non-ideal nanostructures may result from experimental faults or limits. And they will have an effect on the evaporation of film. In the present study, molecular dynamics is adopted to investigate this effect. The simulation system consists of the liquid sodium film and the solid surface. The flat surface is set as the reference. Based on the three non-ideal shapes of deposition, the sinusoidal nanostructures, conical nanostructures, and spherical nanostructures are built. The results indicate that the evaporation is suppressed by the above nanostructure surfaces. The weakening effect is through three forms: the potential gradient of the liquid film is intensified and the evaporation difficulty is increased;the heat transfer in the solid-liquid contact region is impeded;the collision heat transfer inside the liquid film is affected due to the delay of the aggregation variation between liquid atoms. © 2023 Xi'an Jiaotong University

关键词： Heat pipes

来源：评论

学校读者我要写书评

暂无评论

Study of low-pressure premixed laminar n-heptane+propane/oxygen/nitrogen flames

引用

Chinese Science Bulletin 2009年第9期54卷 1477-1486页

作者： YU Wu WEI LiXia MA ZhiHao HUANG ZuoHua YUAN Tao TIAN ZhenYu LI YuYang 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

Low-pressure premixed laminar n-heptane+propane/oxygen/nitrogen flames were investigated with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry. Three flames with different mass percentage of propane in the fuel blends of 0%, 1.%, and 20% were studied. The combustion intermediates were identified by comparing the measured IEs with those values in literatures. Mole fraction profiles of the main species were compared among the three flames. The experimental results provide detailed data in understanding the combustion of n-heptane and n-heptane/propane blends in engine. They are also helpful in establishing and verifying the kinetic models.

关键词：正庚烷火焰丙烷混层低压氮氧真空紫外

来源：评论

学校读者我要写书评

暂无评论

Performance and emission characteristics of a hydrogen-enriched compressed-natural-gas direct-injection spark ignition engine diluted with exhaust gas recirculation

Performance and emission characteristics of a hydrogen-enric...

引用

作者： Liu, Y.-F. Liu, B. Zeng, K. Huang, Z. Zhou, L. Sun, L. State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Compressed natural gas (CNG) has been widely used in city buses or taxis because of its relatively low price and great abundance. Most of the CNG engines externally mix the natural gas with the intake air and utilize a lean-burn strategy to achieve low nitrogen oxide (NOx) emissions and high fuel economy. However, the well-examined external mixing of gas fuel with the intake air will result in a volumetric efficiency loss at high engine loads and may cause backfire when the natural gas is enriched with hydrogen. Also, the lean-burn technique may not sufficiently satisfy increasingly restricted future legislation. In this paper, the use of the stoichiometric equivalence ratio with exhaust gas recirculation (EGR) was investigated experimentally on a direct-injection spark ignition engine fuelled with hydrogen-natural-gas blends. Attention is focused on the advantages of combining EGR with hydrogen enrichment. The results show that hydrogen enrichment increases the brake mean effective pressure, which dramatically deteriorates under high-level EGR. Optimal efficiencies are achieved with an EGR rate of 5-1. per cent;the NO x emissions can be decreased by about 80per cent with 25 per cent EGR dilution, but the combustion variation increases simultaneously. With hydrogen enrichment, the combustion variation can be controlled under 5per cent, while the NOx, hydrocarbon, and carbon monoxide emissions are kept at a low level. Worse EGR tolerance was exhibited for the late-injection-timing case. © Author 201..

关键词： Efficiency

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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：