检索结果-内蒙古大学图书馆

Study of Unforced Unsteadiness in Centrifugal Pump at Partial flow Rates

Journal of Thermal Science 2021年第1期30卷 88-99页

作者： YANG Jun XIE Tian LIU Xiaohua SI Qiaorui LIU Jun School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Fluid and Power Machinery(Xihua University) Ministry of EducationChengdu 610039China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China

In order to explore the unforced unsteadiness of centrifugal pumps,a 2-D frequency domain imaging display technology was used to study the development of these unsteady flow structures at partial flow *** results showed that,the unsteady flow field was not only affected by rotor and stator interaction,but also appeared an unforced unsteadiness with fundamental frequency of St≈0.23 around the impeller throat ***,as the flow rates decreased,this unsteady flow structure gradually weakened and *** the flow rate was reduced to 0.6 times of design flow rate,another two unforced unsteady flow structures with characteristic frequencies of St≈0.0714 and St≈0.12 began to appear in the same ***,with the operating condition smaller than design flow rate,the internal flow became more and more *** addition to the forced unsteadiness,the unforced unsteadiness which is not connected with the blade passage frequency became more and more obvious.

关键词： centrifugal pumps partial flow conditions pressure pulsations unforced unsteadiness 2-D frequency domain visualization method

来源：评论

学校读者我要写书评

暂无评论

A review of progress in thermo-mechanical energy storage technologies for combined cooling,heating and power applications

引用

能源前沿（英文） 2025年第2期19卷 117-143页

作者： Jiaxing Huang Yao Zhao Jian Song Shengqi Huang Kai Wang Zhenghua Rao Yongliang Zhao Liang Wang Xi Wan Yue Fei Christos N.Markides College of Smart Energy Shanghai Jiao Tong UniversityShanghai 200240China College of Smart Energy Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Non-carbon Energy Conversion and Utilization Institute Shanghai Jiao Tong UniversityShanghai 200240China Birmingham Centre for Energy Storage & School of Chemical Engineering University of BirminghamBirmingham B15 2TTUK Clean Energy Processes(CEP)Laboratory Department of Chemical EngineeringImperial College LondonLondon SW7 2AZUK Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhou 310027China Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province Zhejiang UniversityHangzhou 310027China School of Energy Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China Clean Energy Processes(CEP)Laboratory Department of Chemical EngineeringImperial College LondonLondon SW7 2AZUK

Thermo-mechanical energy storage(TMES)technologies have attracted significant attention due to their potential for grid-scale,long-duration electricity storage,offering advantages such as minimal geographical constraints,low environmental impact,and long operational lifespans.A key benefit of TMES systems is their ability to perform energy conversion steps that enable interaction with both thermal energy consumers and prosumers,effectively functioning as combined cooling,heating and power(CCHP)*** paper reviews recent progress in various TMES technologies,focusing on compressed-air energy storage(CAES),liquid-air energy storage(LAES),pumped-thermal electricity storage(PTES,also known as Carnot battery),and carbon dioxide energy storage(CES),while exploring their potential applications as extended CCHP systems for ***-economic analysis indicate that TMES-based CCHP systems can achieve roundtrip(power-to-power)efficiencies ranging from 40％to 130％,overall(trigeneration)energy efficiencies from 70％to 190％,and a levelized cost of energy(with cooling and heating outputs converted into equivalent electricity)between 70 and 200 $/*** general,the evolution of TMES-based CCHP systems into smart multi-energy management systems for cities or districts in the future is a highly promising ***,current economic analyses remain incomplete,and further exploration is needed,especially in the area"AI for energy storage,"which is crucial for the widespread adoption of TMES-based CCHP systems.

关键词： thermo-mechanical energy storage(TMES) combined cooling heating and power compressed-air energy storage(CAES) liquid-air energy storage(LAES) pumped-thermal energy storage(PTES) carbon dioxide energy storage(CES)

来源：评论

学校读者我要写书评

暂无评论

Proposal and thermodynamic analysis of a steam methane reforming system integrated with thermochemical energy storage and a SCO2 brayton cycle

引用

Journal of Energy Storage 2025年 127卷

作者： Fu, Yu Liu, Ming Wang, Zhu Xie, Tao Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Institute of Industrial Catalysis School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an710049 China

Solar energy is a promising alternative to fossil fuels for providing heat in steam methane reforming (SMR) hydrogen production. However, the variability of solar energy requires effective storage solutions. This study presents a new SMR hydrogen production system that integrates thermochemical energy storage (TCES) utilizing a CaO/CaCO3 cycle with a SCO2 Brayton cycle. The system converts fluctuating solar energy into the stable chemical energy of CaO by calcinating CaCO3 in the solar calciner, with the SMR reaction mainly heated by the exothermic reaction of CaO and CO2. The SCO₂ Brayton cycle efficiently recovers heat from the high-temperature SMR products. Comprehensive thermodynamic analysis and evaluation models are developed. Results show that the proposed system performs well, achieving energy and exergy efficiencies of 73.49 % and 78.46 %, respectively, under benchmark conditions. The energy storage efficiency of TCES is 81.55 %, and the solar-to-chemical energy efficiency is 48.21 %. Integrating TCES significantly enhances the system's steady operation under fluctuating solar energy conditions. The calciner accounts for the largest share of exergy destruction at 31.63 %, followed by the carbonator at 17.50 %. Sensitive analyses of key operating parameters indicate that higher CaO conversion rate and storage temperature enhance energy storage, energy, and exergy efficiencies. Besides, the energy and exergy efficiencies decrease with the increasing SMR reaction pressure but increase with rising reaction temperature. When the S/C is 2.0, these efficiencies reach their maximum values of 75.42 % and 78.63 %, respectively. © 2025 Elsevier Ltd

关键词： Brayton cycle

来源：评论

学校读者我要写书评

暂无评论

Experimental and numerical investigation of two phase ejector performance with the water injected into the induced flow

引用

International Journal of Advanced Nuclear Reactor Design and Technology 2020年 2卷 15-24页

作者： Chen, WeiXiong Huang, ChenXi Bai, YuPing Chong, DaoTong Yan, JunJie Liu, JiPing State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

When injectors are used in petroleum industries or sea water desalination system, it is a special case that the induced gas is accompanied by water, the ejector is in two-phase operation. In the present study, the ejector performance at two phase flow is investigated experimentally and numerically. The results indicate that: the entrainment ratio would decrease when the water is injected into the induced flow, as well as the pressure ratio. The maximum decrement of entrainment ratio is around 40.5% at sub-critical mode when the motive pressure is 1.0 MPa, the induced pressure is 0.2 MPa, liquid-air ratio is 22%. For the pressure ratio, the maximum decrement is 62.5% when the motive pressure is 1.0 MPa, the induced pressure is 0.5 MPa, liquid-air ratio is 2.87%. However, the lower the induced pressure is, the more obvious the effect of mass flow rate on entrainment rate is, while the effect on pressure ratio is just opposite. Moreover, the performance becomes worse in sub-critical mode than that in critical mode. The effect of NXP on ejector performance also has been analyzed. There exists an optimum NXP whether the two phase flow ejector is in critical mode or sub-critical mode. The optimum NXP for entrainment ratio enlarges from 3.6 mm to 4.4 mm with the increase of water mass flowrate, and is bigger than that of single phase ejector (the optimum NXP is 2.8 mm). This study may provide a beneficial reference for the operation of supersonic ejectors on two phase flow. © 2020 Xi'an Jiaotong University

关键词： Two phase flow

来源：评论

学校读者我要写书评

暂无评论

Sequential Growth of Cs_(3)Bi_(2)I_(9)/BiVO_(4)Direct Z-Scheme Heterojunction for Visible-Light-Driven Photocatalytic CO_(2)Reduction

引用

Transactions of Tianjin University 2023年第6期29卷 462-472页

作者： Long Jiang Hanrui Du Le Li Xiangjiu Guan Yihao Zhang Liwei Li Xiaoxu Liu Lei Li Yingcheng Tian Li Zhang Shuai Wang Jie Chen Shaohua Shen State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi’an 710077China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China CNPC National Engineering Research Center for Oil and Gas Drilling Equipment Co. Ltd.Baoji 721002China China Coal Energy Research Institute Co. Ltd.Xi’an 710049China

The high exciton binding energy and lack of a positive oxidation band potential restrict the photocatalytic CO_(2)reduction efficiency of lead-free Bi-based halide perovskites Cs_(3)Bi_(2)X_(9)(X=Br,I).In this study,a sequential growth method is presented to prepare a visible-light-driven(λ>420 nm)Z-scheme heterojunction photocatalyst composed of BiVO_(4)nanocrystals decorated on a Cs_(3)Bi_(2)I_(9)nanosheet for photocatalytic CO_(2)reduction coupled with water *** Cs_(3)Bi_(2)I_(9)/BiVO_(4)Z-scheme heterojunction photocatalyst is stable in the gas-solid photocatalytic CO_(2)reduction system,demonstrating a high visible-light-driven photocatalytic CO_(2)-to-CO production rate of 17.5μmol/(g·h),which is approximately three times that of pristine Cs_(3)Bi_(2)I_(9).The high efficiency of the Cs_(3)Bi_(2)I_(9)/BiVO_(4)heterojunction was attributed to the improved charge separation in Cs_(3)Bi_(2)I_(9).Moreover,the Z-scheme charge-transfer pathway preserves the negative reduction potential of Cs_(3)Bi_(2)I_(9)and the positive oxidation potential of BiVO_()*** study off ers solid evidence of constructing Z-scheme heterojunctions to improve the photocatalytic performance of lead-free halide perovskites and would inspire more ideas for developing leadfree halide perovskite photocatalysts.

关键词： Lead-free halide perovskite Z-scheme heterojunction CO_(2)reduction Visible-light photocatalysis Charge transfer

来源：评论

学校读者我要写书评

暂无评论

Experimental study on dynamic mechanism of vortex evolution in a turbulent boundary layer of low Reynolds number

引用

Journal of Hydrodynamics 2020年第5期32卷 807-819页

作者： Yan-ang Guo Xiang-rui Dong Xiao-shu Cai Wu Zhou School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Multiphase Flow and Heat Transfer in Shanghai Power Engineering Shanghai 200093China

The dynamic mechanism of the vortex generation and evolution process in a fully developed turbulent boundary layer with Reθ=97-194 is experimentally *** this study,a moving single-frame and long-exposure(MSFLE)imaging method and a moving particle image velocimetry/particle tracing velocimetry(M-PIV/PTV)are designed and implemented for measuring the temporal and spatial evolution of vortex cores in both qualitative and quantitative ways,*** the other hand,the Liutex vector,which is a new mathematical definition and identification of the vortex core proposed by Liu’s group,is first applied in the experiment for the structural visualization and quantitative analysis of the local fluid *** results show that an intuitional process of vortex evolution can be clearly observed by tracking the vortex using MSFLE and verify that the roll-up of the shear layer induced by shear instability is the origin of vortex formation in ***,a quantitative investigation in terms of the critical vortex core boundary(size)and its accurate rotation strength is carried out based on the Liutex vector field analysis by M-PIV/*** to statistics of the relation between vortex core size and the rotation strength during the whole process,the physical mechanism of vortex generation and evolution in a turbulent boundary layer of low Reynolds number can be summarized as a four-dominant-state course consisting of the“synchronous linear segment(SL)-absolute enhancement segment(AE)-absolute diffusion segment(AD)-skewing dissipation segment(SD)”.

关键词： Turbulent boundary layer high-and low-speed fluid vortex generation moving single-frame and long-exposure moving particle image velocimetry/particle tracing velocimetry Liutex vector

来源：评论

学校读者我要写书评

暂无评论

Investigation on the Mechanism of Co2 Hydrate Formation by Synergistic Action of Kinetic Promoters

SSRN

引用

SSRN 2023年

作者： Liu, Ni Leng, Jing Cui, Mengxue Yang, Liang School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China

CO2 hydrate technology has a promising application in carbon neutralization through carbon capture. In this paper, the effect of different mass concentrations of fullerene C60 and sodium lignosulfonate (SL) on the gas storage performance of CO2 hydrate was investigated. C60 can promote the best results at the concentration of 0.01 wt%. The induction time was 168 minutes, and the gas storage capacity was 56.60 V/V, which is 112.22% higher than that of pure water. This is due to the large specific surface area of C60 nanoparticles, which reduces the surface tension of the solution and increases the gas-liquid mass transfer rate. SL can promote the best results at the concentration of 0.1 wt%. The induction time was 1,908 minutes, and the gas storage capacity was 89.98 V/V, which is 2.37 times higher than that in the pure water system. This is because SL molecules possess abundant functional groups, high chemical reactivity, high elasticity and surface activity. The best compounding pair was in the experimental group of 0.01 wt% C60 with 0.1 wt% SL. The induction time was 60 minutes, and the gas storage capacity was 108.87 V/V. Therefore, both C60 and SL have a positive effect on CO2 hydrate formation. © 2023, The Authors. All rights reserved.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Digital twin modeling and fault diagnosis on the feedwater pump system of thermal power plant

Digital twin modeling and fault diagnosis on the feedwater p...

引用

Digital Twins and Parallel Intelligence (DTPI), IEEE International Conference on

作者： Yugang Liu Chi Luo Chen Chen Zhu Wang Ming Liu Clean Combustion and Flue Gas Purification Key Laboratory of Sichuan Province Dongfang Boiler Co. Ltd Chengdu China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

ISBN: (数字)9798350349252

ISBN: (纸本)9798350349269

The high penetration of renewable energy introduces increased volatility into the power system, presenting more challenging peak shaving and frequency modulation missions for thermal power plants that serve as schedulable power sources within the system. Frequent load cycling place higher demands on the operation stability of core power plant equipment and introduce additional safety risks. As the core system of the power cycle, the operational reliability and energy efficiency of the feedwater pump system (FPS) are crucial. Therefore, this paper focuses on the core equipment and parameters of the FPS, developing a digital twin model based on mechanism modeling method and neural network data-driven modeling method. By comparing the mean absolute error, root mean square error, and coefficient of determination of simulation parameters of different modeling methods, digital twin parameters with higher simulation accuracy were obtained. Utilizing these predicted parameters, an FPS fault diagnosis model (FFDM) for the FPS was developed. By calculating comprehensive deviation degree and the contribution of each parameter, fault early warning and source tracing were achieved, providing guidance for the closed-loop control.

关键词： Fault diagnosis Data-driven modeling Neural networks Predictive models power system stability Energy efficiency Digital twins Safety power system reliability power generation

来源：评论

学校读者我要写书评

暂无评论

Understanding the Reversal Dilution Effect of the Species Sampling in the Negative Temperature Coefficient Region

SSRN

引用

SSRN 2023年

作者： Wu, Yingtao Mai, Zhaoming Rao, Boxuan Liu, Jie Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi'An710049 China Department of Power Mechanical Engineering Beijing Jiaotong University Beijing100044 China

Species sampling during fuel autoignition can provide valuable insights in studying the chemical kinetic mechanism. Various species sampling techniques have been developed for speciation quantification in different reactors. However, unavoidable dilution in the physical sampling brings uncertainty to the measurements, particularly in the negative temperature coefficient (NTC) region where the effect of dilution remains unclear. To address this issue and improve measurement accuracy, numerical species samplings during the autoignition of n-butane mixture were studied in a rapid compression machine reactor. Results show that greater fuel consumption and intermediate generation were observed in regions with lower temperatures instead of the hot core zone. Therefore, the dilution effect on the sampling results is reversed inside the NTC region. Furthermore, results from two typical sampling methods were compared with the target core profiles to determine their uncertainties. Lastly, the feasibility of applying dilution ratio calibration on the sampling results in the NTC region was tested, which indicates the necessity of considering the NTC effect, particularly for intermediates with low concentrations. Alternatively, increasing the sampling duration of the fast-sampling method effectively reduces the uncertainty of species concentration and enhances the robustness of mechanism validation regardless of the NTC behavior. © 2023, The Authors. All rights reserved.

关键词： Temperature

来源：评论

学校读者我要写书评

暂无评论

Experimental and Numerical Study of Hydraulic Characteristics and Pressurization Deterioration Mechanism of a Three-Stage Mixed-flow multiphase Pump Under Gas Liquid Condition

SSRN

引用

SSRN 2023年

作者： Dai, Xiaoyu Xu, Qiang Yang, Chenyu Su, Xiaobin Chang, Liang Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Shanghai Institute of Satellite Engineering Shanghai201109 China

The mixed-flow multiphase pump may experience pressurization deterioration due to the high Gas Volume Fraction, resulting in pressurization failure and posing a threat to the pressurization unit's safety. In this paper, a three-stage mixed-flow multiphase pump with closed impeller structure is designed and developed. The hydraulic characteristics and pressurization deterioration mechanism of the multiphase pump were investigated at various rotational speeds and inlet conditions using the experiment and simulation. As the liquid flow rate rises, the multiphase pump experiences a 'three-stage' downward trend in pressurization. The first booster stage has a greater capacity for pressurizing the liquid phase. The gas-liquid pressurization exhibits a wave-shaped downward trend due to significant deterioration in stage-wise pressurization when the liquid flow rate is low. Once the Inlet Gas Volume Fraction reaches the initial critical Gas Volume Fraction, the gas aggregates on the impeller’s suction surface is removed at the impeller outlet, creating an annular air mass. When this mass of air meets the fluid behind it, it creates a chaotic vortex that absorbs the fluids' kinetic energy. As a result, the first booster stage experiences a significant reduction in its pressurization ability, causing an abrupt decrease in the pressurization curve. © 2023, The Authors. All rights reserved.

关键词： Computational fluid dynamics

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：