检索结果-内蒙古大学图书馆

Performance Analysis of Cooling Wall of Supercritical CO_(2) Coal-Fired Plants

Journal of Thermal Science 2022年第6期31卷 1881-1890页

作者： WANG Yanjuan YU Binhui GAO Shuo LIU Qibin XU Jinliang The Beijing Key Laboratory of Multiphase Flow and Heat Transfer North China Electric Power UniversityBeijing 102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Using supercritical CO_(2)(S-CO_(2)) instead of water steam as heat transfer fluid for coal-fired power plants is another way to further improve the power generation efficiency. In this paper, a multi-field coupling model that integrates fluid flow, heat transfer and thermal stress is proposed to solve the complex problem. The effects of the key operating parameters on the performances of the cooling wall are numerically investigated. More details of the characteristics of fluid dynamics, thermal stress, pressure drop, coupled heat transfer and the whole flow and temperature fields in the S-CO_(2) cooling wall are revealed and discussed. A comparison study is made between the cooling wall tube and waterwall tube. Both temperature and thermal deformations of cooling wall tube are much higher than that of water. Numerical simulation results indicate that inclination angle has little effects on the temperature distribution, while increase of pressure drop is obvious as the inclination angle increases. Increasing tube diameter can effectively reduce both the pressure drop and the temperature of the cooling wall tube. As a result, a new insight is introduced for the design of S-CO_(2) power cycle.

关键词： supercritical CO_(2) cooling wall coal-fired power plant heat transfer

来源：评论

学校读者我要写书评

暂无评论

Recent advances in nonmetallic atom-doped metal nanocrystals:Synthesis and catalytic applications

引用

Chinese Chemical Letters 2021年第9期32卷 2679-2692页

作者： Ruiyun Guo Ke Zhang Shangdong Ji Yangzi Zheng Mingshang Jin Frontier Institute of Science and Technology and State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China

Metal nanocrystals have been recognized as the main catalytic materials in many fields,but insufficient activity and stability,as well as high prices,have limited their large-scale potential *** one of the extremely promising alternatives toward metal in boosting their catalytic performance,nonmetallic atoms-doped metal nanocrystals have recently received extensive attention because of their high efficiency,chemical and structural durability,abundant reserve,and low *** this review,we highlight the most recent progress in this field and provide insights into their catalytic *** metalnonmetal nanocrystals prepared by doping metal nanocrystals with nonmetallic atoms are introduced and classified based on the types of nonmetallic atoms,including metal hydrides,borides,carbides,nitrides,oxides,phosphides,and ***,their applications in catalysis,especially in electrocatalysis and organic catalysis,have been summarized and ***,the conclusions and perspectives are given for the catalysis-driven rational design of metal-nonmetal nanocrystals in this minireview.

关键词： Nonmetallic atom-doping Metal-nonmetal nanocrystals Organic catalysis Electrocatalysis Catalyst design

来源：评论

学校读者我要写书评

暂无评论

Molecular Dynamics Simulation Investigation of the Solubility Parameter of Supercritical Carbon Dioxide-Cosolvent

Molecular Dynamics Simulation Investigation of the Solubilit...

引用

International Multidisciplinary Conference on Computer and Energy Science (SpliTech)

作者： Junying Wang Hui Jin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an China

ISBN: (数字)9789532901351

ISBN: (纸本)9798350390797

In this work, solubility parameters of the supercritical carbon dioxide (SC-CO2) system and the SC-CO2 adding cosolvent systems were calculated using molecular dynamics simulation. How temperature and pressure changes affected the solubility parameter were studied by molecular dynamics simulation. In addition, the mechanism of interaction between cosolvent and SC-CO2 was investigated. It was discovered that the SC-CO2 solubility parameter rose with rising pressure at constant temperature and fell with rising temperature at constant pressure. Additionally, it is obvious that increasing the solubility parameter of the SC-CO2 system as a whole can be achieved by adding a specific quantity of cosolvent. The solubility parameter of the SC-CO2-cosolvent system increased with increasing cosolvent content. The addition of cosolvent to improve the solubility parameter works by increasing the combined system's polar strength. The hydrogen bonding interaction energy has the greatest impact on the increase of solubility parameter.

关键词： Ethanol Hydrogen Carbon dioxide Bonding Carbon

来源：评论

学校读者我要写书评

暂无评论

Rotor dynamic analysis of supercritical carbon dioxide Bryton cycle coaxial integrated unit 14

Rotor dynamic analysis of supercritical carbon dioxide Bryto...

引用

14th IEEE Global Reliability and Prognostics and Health Management Conference, PHM-Hangzhou 2023

作者： Xu, Xiaokang Yang, Yi Wang, Jiangfeng Lou, Juwei Chen, Liangqi State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an China Laboratory of Science and Technology on Integrated Logistics Support College of Intelligence Science and Technology National University of Defense Technology Changsha China

ISBN: (纸本)9798350301359

The rotor system plays a very important role in supercritical carbon dioxide Brayton cycle system, and its dynamic problem will directly affect the motion stability and safety of the whole unit. In this paper, the rotor dynamic model of supercritical CO2 coaxial unit is established by finite element method, and the critical speed, modal shape and unbalance response of the rotor are studied. The first seven critical speed of the rotor and the first seven natural frequency of the rotor at the working speed are calculated. The bending modal of the rotor and the position where the rotor amplitude is the largest are analyzed, which can provide reference for the optimization design of the rotor stability. The influences of mass unbalances at the operational speed of rotor are analyzed. The research can provide some suggestions for the optimal design and actual operation of the supercritical CO2 coaxial integrated unit. © 2023 IEEE.

关键词： critical speed unbalance response vibration analysis

来源：评论

学校读者我要写书评

暂无评论

Preferential Formation of Ethylene via Electrocatalytic CO_(2) Reduction on Mesoporous Cu_(2)O Nanoparticles:Synergistic Effects of Pore Structure Confinement and Surface Amine

引用

Chinese Journal of Chemistry 2024年第16期42卷 1846-1852页

作者： Haifeng Zhang Dun Li Zhifang Chen Yingying Wang Haoyu Sun Feng Liu Maochang Liu Yiqun Zheng Hongwen Huang School of Chemistry Chemical Engineering and MaterialsJining UniversityQufuShandong 273155China College of Materials Science and Engineering Hunan UniversityChangshaHunan 410082China Health Management Department Shandong Vocational College of Light IndustryZiboShandong 255300China International Research Center for Renewable Energy National Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiotong UniversityXi'anShaanxi 710049China

We present a facile synthetic strategy to create mesoporous Cu_(2)O nanocrystals with tunable pore structures and surface functional groups of amine derivatives for efficient and preferable electrochemical conversion of CO_(2) into *** structural characteristics of theseCu_(2)O nanocrystals can be manipulated using a set of amine derivatives,such as pyridine,4,4'-bipyridine,and hexamethylenetetramine,during the oxidative etching process of Cu nanocrystals by bubbling gaseous oxygen in N,N-dimethylformamide *** amine derivatives not only serve as surface functional groups but also significantly affect the resulting pore *** synergistic effect of pore structure confinement and surface amine functionalization leads to the superb Faradaic efficiency(FE)of 51.9% for C_(2)H_(4),respectively,together with the C_(2)H_(4) partial current density of -209.4 mA·cm^(-2) at -0.8 V *** hydrogen electrode(RHE).The relatively high selectivity towards C_(2)H_(4) was investigated using DFT simulations,where 4,4'-bipyridine functionalized Cu_(2)O seemed to favor the C_(2)H_(4) formation with the low free energy of the *** study provides a feasible strategy to manipulate the pore structure and surface functionalization of mesoporous Cu_(2)O nanocrystals by regulating the oxidative etching process,which sheds light on the rational preparation of high-performance CO_(2)RR electrocatalysts.

关键词： Amines Ethylene Cuprous oxide CO_(2)reduction Mesoporous materials

来源：评论

学校读者我要写书评

暂无评论

engineering practice and economic analysis of ozone oxidation wet denitrification technology

引用

Chinese Journal of Chemical engineering 2021年第1期34卷 401-408页

作者： Yang Li Defu Che Chenglong Yang Mingyu Yao Tingwen Zhao Kangli Fu Hanchen Zhao Xi’an Thermal Power Research Institute Co LtdXi’an 710032China State Key Laboratory of Multiphase Flow for Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

SO_(2)and NO emitted from coal-fired power plants have caused serious air pollution in *** this study,a test system for NO oxidation using O_(3)is *** basic characteristics of NO oxidation and products forms are studied.A separate test system for the combined removal of SO_(2)and NO_(x)is also established,and the absorption characteristics of NO_(x)are *** characteristics of NO oxidation and NO_(x)absorption were verified in a 35 t·h^(-1)industrial boiler wet combined desulfurization and denitrification *** operating economy of ozone oxidation wet denitrification technology is *** results show that O_(3)has a high rate and strong selectivity for NO *** O_(3)is insufficient,the primary oxidation product is NO_(2).When O_(3)is present in excess,NO_(2)continues to get oxidized to N_(2)O_(5)or NO_(3).The removal efficiency of NO_(2)in alkaline absorption system is low(only about 15%).NOx removal efficiency can be improved by oxidizing NO_(x)to N_(2)O_(5)or NO_(3)by increasing ozone *** the molar ratio of O_(3)/NO is 1.77,the NOx removal efficiency reaches 90.3%,while the operating cost of removing NO_(x)per kilogram is 6.06 USD(NO_(2)).

关键词： Ozone Denitrification Wet process engineering practice

来源：评论

学校读者我要写书评

暂无评论

Numerical study of specific C-shaped heat exchanger using porous medium and coarse mesh coupling method

引用

International Journal of Thermal Sciences 2025年 210卷

作者： He, Shaopeng Wang, Shiqi Wang, Mingjun Tian, W.X. Qiu, S.Z. Su, G.H. State Key Laboratory of Multiphase Flow in Power Engineering School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an710049 China

Porous medium method is an effective simplified approach for the heat exchanger simulation when the numerous tubes and complex structures bring unacceptable computational resources to full-scale simulation. However, for the specific C-shaped heat exchanger, the tube side resistance and flow distribution characteristics that significantly affects the heat transfer and natural circulation performance cannot be obtained by the traditional porous medium method coupled with the one-dimensional node model for tube side. It is urgent to develop a new coupling method that can not only simplify modeling and calculation, but also obtain tube side high-resolution flow heat transfer characteristics. This study presents a novel calculation method which couples the porous medium mesh and the tube side coarse mesh. The coupling method was then applied to a typical C-shaped passive residual heat removal heat exchanger (PRHR HX), which is significant to the stable operation and the mitigation of accident conditions in the nuclear power plant. The coupling calculation method was validated against the full-scaled simulation and data from scaled-down experiment. The average relative error of heat transfer power is 2.1 % under steady state conditions. Under transient conditions, the average absolute error of the fluid temperature and wall temperature are less than 6 K. Then the 3D thermal-hydraulic characteristics of PRHR HX was studied. Owing to a greater gravitational pressure head, the mass flow rates in the extended tubes surpass those in the shorter tubes by a relative deviation of 27.4 %. The upper horizontal tube's heat exchange capacity constitutes approximately 70 % of the total power, leading to enhanced natural circulation. The outlet temperatures from various tubes tend to equalize. The boiling area gradually extended down along the heat transfer tubes. Our work would present an innovative calculation method to the numerical study and design optimization of the C-shaped heat

关键词： Nuclear power plants

来源：评论

学校读者我要写书评

暂无评论

Comparative experimental study on dynamic characteristics of bubble microlayers in small channel flow boiling and pool boiling 6

Comparative experimental study on dynamic characteristics of...

引用

6th International Conference on Fluid Mechanics and Industrial Applications, FMIA 2022

作者： Shen, Zhongxiang Gao, Ming Dong, Wuhan Zhang, Lixin Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China

The microlayer present at the bottom of the bubble plays a very important role in heat transfer during nucleation boiling. In this paper, the dynamic characteristics of microlayer at the bottom of boiling bubble in a small channel were studied by laser interferometry method and high speed camera, and the results were compared with pool boiling experiments. The results show that the bubbles have an obvious tendency to slip in the flow boiling. The microlayer interference fringe is deformed and no longer a complete Newtonian ring. By analyzing the thickness distribution of microlayer in different directions in flow boiling and the change of micro-contact angle in the flow direction, it was found that the micro-contact angle in the flow direction became larger with the growth of bubbles. © Published under licence by IOP Publishing Ltd.

关键词： Contact angle

来源：评论

学校读者我要写书评

暂无评论

Study on boiling heat transfer mechanism based on microlayer evaporation theory 6

Study on boiling heat transfer mechanism based on microlayer...

引用

6th International Conference on Fluid Mechanics and Industrial Applications, FMIA 2022

作者： Dong, Wu-Han Gao, Ming Shen, Zhong-Xiang Zhang, Li-Xin Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China

Based on dynamic microlayer evaporation model. Heat transfer mechanism of nuclear boiling and microlayer thickness under single bubble on heated surface. It has a lot to do with the temperature of the wall. Therefore, this paper studies the mechanism of bubble microlayer and makes comparative analysis with its experiments. It is helpful to master nuclear boiling heat transfer more comprehensively. In the study of individual bubble microlayer thickness. The effects of time and radius on wall temperature are considered in this paper. The theoretical formula of initial thickness of microlayer is deduced. The theoretical formula is compared with the experimental data of microlayer evaporation under the nucleation bubble. It was found that the experimental data fell within ±25% of the formula range. It is consistent with the previous experimental research. © Published under licence by IOP Publishing Ltd.

关键词： Evaporation

来源：评论

学校读者我要写书评

暂无评论

Research on the THMC Coupling Model for Enhanced Geothermal Systems Based on the Framework of EDFM 29th

Research on the THMC Coupling Model for Enhanced Geothermal ...

引用

29th International Conference on Computational and Experimental engineering and Sciences, ICCES 2023

作者： Zhang, Weitao Han, Dongxu Jiao, Kaituo Chen, Yujie Yuan, Qing Gong, Liang Yu, Bo Qingdao266580 China Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil and Gas Development School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing102617 China State Key Laboratory of Multiphase Flow in Power Engineering School of Chemical Engineering and Technology Xi’an Jiaotong University Xi’an710049 China

ISBN: (纸本)9783031429866

The Enhanced Geothermal System (EGS) involves a complex thermo-hydro-mechanical-chemical (THMC) coupling process during long-term heat extraction. However, many models used to solve fractured reservoir problems are computationally time-consuming, especially when dealing with reservoir-scale engineering problems. To address this challenge, this paper proposes a novel THMC coupling model that solves the governing equations using a unified FVM framework based on the embedded discrete fracture model (EDFM). The accuracy of the model is confirmed by comparing the THC coupling and displacement (M) results with the Fully Resolved Solution Method (FRSM) from MRST software and COMSOL, respectively. Moreover, the model developed is utilized to simulate and analyze the spatiotemporal behavior of pressure, temperature, concentration, and mechanical deformation in EGS. The results suggest that the model is appropriate for effectively assessing the long-term production performance of EGS. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Finite volume method

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：