检索结果-内蒙古大学图书馆

Thermodynamic Analysis of a Hybrid Energy System Coupling Solar Organic Rankine Cycle and Ground Source Heat Pump: Exploring Heat Cascade Utilization

SSRN

引用

SSRN 2023年

作者： Chen, Liangqi Yue, Huifeng Wang, Jiangfeng Lou, Juwei Wang, Shunsen Guo, Yumin Deng, Bohao Sun, Lu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China China United Northwest Institute for Engineering Design & Research Co. Ltd Xi’an710077 China School of Human Settlements and Civil Engineering Xi'an Jiaotong University Xi’an710049 China

The demand for efficient utilization of renewable energy is growing and the hybrid energy system driven by solar and geothermal energy is a significant way to minimize carbon emission and achieve carbon neutrality. This paper presents a hybrid energy system coupling solar organic Rankine cycle (S-ORC) with ground source heat pump (GSHP) for heating and power supply to further increase thermal efficiency and explore the heat cascade utilization of hybrid energy system during the heating season. In the hybrid energy system, the ground heat exchanger (GHE) is shared by the S-ORC and GSHP systems and the waste heat from the condenser of S-ORC is recovered to enhance the coefficient of performance (COP) of GSHP. A mathematical model is optimized to analyze the parametric effects on thermodynamic performance under different operating conditions. The comparison between the hybrid energy system and the stand-alone GSHP system is performed to present the superiority of energy recycling. The results indicate that the COP of the hybrid energy system can be improved up to 6.5 which shows the obvious advantage compared to 2.8 of the stand-alone GSHP system under the given system conditions. In addition, the increase of turbine inlet pressure can not only reduce the area of solar fields and length of buried tubes, but also contribute to the thermodynamic performance of the hybrid energy system. Furthermore, the hybrid energy system can obtain optimum exergy efficiency by matching ground source temperature and condensation temperature in the ORC unit. For a building of 3000m2 with heating and power supply, multi-objective optimization by means of a genetic algorithm is carried out to obtain the optimal design performance that the net power output, thermal efficiency and exergy efficiency are 180.0kW, 27.5%, and 9.2% respectively. © 2023, The Authors. All rights reserved.

关键词： Geothermal heat pumps

来源：评论

学校读者我要写书评

暂无评论

Novel doped barium cerate-carbonate composite electrolyte material for low temperature solid oxide fuel cells

Novel doped barium cerate-carbonate composite electrolyte ma...

引用

第五届世界氢能技术大会(WHTC2013)

作者： Yuanfei Hei Cheng Wang Jianbing Huang Zongqiang Mao Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084P.R. China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049P.R. China

来源：评论

学校读者我要写书评

暂无评论

Propagation and Burning Velocity of Iron-Methane-Oxygen-Nitrogen Turbulent Expanding Flames

SSRN

引用

SSRN 2023年

作者： Cai, Xiao Su, Limin Su, Shouguo Wang, Jinhua Alden, Marcus Li, Zhongshan Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Division of Combustion Physics Lund University P.O. Box 118 LundS221 00 Sweden

The propagation and burning velocity of iron-methane-oxygen-nitrogen turbulent expanding flames were experimentally studied by employing a newly optimized spark-ignition, fan-stirred combustion chamber, in which micron-sized iron particles can be dispersed homogeneously. Fine iron particles with averaged diameter of 1.9 μm was used in the present study. The flame trajectory of iron-methane mixture at different turbulence intensities and iron concentrations was recorded using a high-speed camera. It was found that the flame propagation speed increases as iron-methane turbulent flame expands. The acceleration process is mainly caused by the extension of flame surface dissipation spectrum by increasing the largest flame scales (flame radius). The turbulent burning velocity, ST increases significantly with the turbulence intensity, which is well known feature in gaseous flames. However, the iron concentration does not have an obvious effect on the ST, which is unique to iron flame in turbulence environment. Because the turbulent flame propagation is dominated by turbulent heat transfer, which is characterized by turbulence intensity. In addition, the formation of iron flame front is controlled by the couple effects of iron concentration and turbulence intensity in turbulent environment. Furthermore, the laminar burning velocity, SL was accurately determined using a nonlinear extraction method. A correlation of turbulent burning velocity was obtained based on the experimental iron-methane data. The measured ST and its correlation would be used to develop practical iron burners and to validate turbulent combustion models of iron flames. © 2023, The Authors. All rights reserved.

关键词： Iron

来源：评论

学校读者我要写书评

暂无评论

Ethylene Oxidation with Ce-Modified Fe-Based Oxygen Carrier: Fuel Combustion Efficiency Improvement

SSRN

引用

SSRN 2022年

作者： Sun, Tianli Wu, Ye Mei, Jian Han, Yinghui Cai, Tianyi Liu, Dong MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing210094 China Advanced Combustion Laboratory School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing210094 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China 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

Improving combustion efficiency of diesel engine is very important in the current background of carbon neutralization because sufficient combustion means low pollutant emission and little energy waste. In past studies, catalytic coatings were used in diesel engine to speed up fuel-burning rates and reduce emissions caused by insufficient combustion. Insufficient combustion mainly in high temperature and low oxygen area, using oxygen carrier as the coating material for the combustor surface to support additional –O and regulate the combustion process also is a promising strategy. A desired Fe-based oxygen carrier with excellent redox capability and stability was fabricated to convert fuel pyrolysis products into CO2, H2O and extra heat to improve the fuel combustion efficiency. A range of cerium modified Fe2O3 oxygen carriers were prepared and tested with ethylene as a representative fuel to investigate the redox capability and stability during fuel pyrolysis process. In addition, the gas-solid surface reaction of ethylene and iron oxide was studied by density functional theory (DFT) to illustrate their good reactivity and the mechanism of doping optimization. It was found that when using the FeCe-2 oxygen carrier with the mole ration of Fe and Ce is 9:1 during ethylene pyrolysis process, the ethylene was oxidized most sufficiently (CO2 yield>92%). DFT simulation showed that Ce doping improved the reactivity of surface oxygen. Experimental data and characterization analysis showed that the addition of Ce improved oxygen vacancy capacity to enhance the oxidation for the pyrolysis products. Due to the role of both, the ethylene and its pyrolysis products were converted into CO2 and H2O quickly and effectively. The obtained results indicate that FeCe-2 is the potential oxygen carrier coating material for combustion efficiency improvement. © 2022, 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

Experimental Study of Pool Boiling Heat Transfer on Hydrophilic and Hydrophobic Surface Coupled Micro-Pin-Finned

SSRN

引用

SSRN 2023年

作者： Song, Gege Ma, Xiang Xu, Pengzhuo Zhang, Yonghai Weia, Jinjia School of Chemical Engineering and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Xi’an Navigation Technology Research Institute Shannxi Xi’an710068 China Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

The pool boiling heat transfer properties of uniform micro-pin-finned surface, hydrophilic and hydrophobic surface were evaluated by employing FC-72 as the working medium. Three hydrophilic and hydrophobic coupled rectangular copper column surfaces (HH4, HH9, and HH16) were invented in order to investigate their boiling heat transfer characteristics further. The effect of several subcoolings (0K, 15K, and 25K) on the critical heat flux was explored by connecting the micro-pin-finned surface (PF) and the smooth surface (SS). A high-speed camera was set up to study the bubbles' behaviors. The results reveal that the hydrophilic and hydrophobic coupled micro-pin-finned copper surface can achieve a higher critical heat flux (CHF) than the rectangular micro-pin-finned surface, but heat transfer performance (HTC) drops slightly (both saturated boiling and subcooling boiling). Visual monitoring demonstrates that the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper surface may successfully avoid bubble coalescence, especially during subcooled boiling. Furthermore, the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper column surface described in this paper might serve as an ideal replenishment route to avoid drying and delay the emergence of a boiling crisis. The factors responsible for the impact of the Lattice width coefficient and the Vapor column spacing coefficient on CHF were analyzed. Fluid replenishment and bubble formation behavior were applied to clarify the strengthened heat transfer and triggering mechanism of CHF on the surface of the hydrophilic and hydrophobic coupled rectangular micro-pin-finned copper column surface. © 2023, The Authors. All rights reserved.

关键词： Heat flux

来源：评论

学校读者我要写书评

暂无评论

Publisher's Note: Numerical investigation of the yawed wake and its effects on the downstream wind turbine [J. Renewable Sustainable Energy 8, 033303 (2016)]

引用

Journal of Renewable and Sustainable Energy 2016年第5期8卷 033303-033303页

作者： Miao, Weipao Li, Chun Yang, Jun Xie, Xiaoyun 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 Laboratory of Fluid and Power Machinery Xihua University Jinniu District Sichuan610000 China Shanghai Behr Thermal Systems Co. Pudong District Shanghai201206 China

A correction to the article 'Numerical investigation of the yawed wake and its effects on the downstream wind turbine' published in the previous issue is presented.

关键词： WIND turbines RENEWABLE energy sources

来源：评论

学校读者我要写书评

暂无评论

Effects of Hydrothermal and Hydrothermal Oxidation Pretreatments on Physicochemical Properties of High Value-Added Biochar Fuel Pellets and Activated Carbon Materials

SSRN

引用

SSRN 2023年

作者： Lang, Sen Zhang, Shouyu Yang, Jifan Zhou, Yi Liu, Simeng Xu, Zihang Han, Xiuyuan Huang, Jiantian 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 Huazhan Aerospace Electric Appliance Co. LTD Aerospace Science and Industry Corporation Suzhou215129 China

In this paper, cotton stalk (CS) and Chinese fir sawdust (FS) were treated for hydrothermal pretreatment with or without H2O2, and then respectively pyrolyzed and activated to prepare biochar pellets and activated carbon materials. The results show that compared with hydrothermal pretreatment (HT), hydrothermal oxidation (HTO) pretreatment has stronger degradation ability of hemicellulose and cellulose. With the increase of pretreatment temperature, some decomposed substances repolymerize to form lignin-like substances. In the 160-260oC temperature range, the physical properties of biochar pellets prepared under HT 230oC and HTO 200oC are the best, and crystalline cellulose plays a key role in it. The calorific value and energy density of the biochar pellets obtained after pretreatment were consistent with the variation trend of their physical properties. The combustion characteristics of treated CS/FS biochar pellets gradually decreased with the increase of temperature. Compared with CS, FS biochar have better energy density and physical properties due to high cellulose content. The CS-HTO200-A has the highest specific surface area and pore volume, which is 118.1% and 111.7% higher than that of raw materials, and mainly consists of micropores. Cellulose is beneficial to increase the specific surface area of activated carbon, while lignin has the opposite effect. © 2023, The Authors. All rights reserved.

关键词： Physicochemical properties

来源：评论

学校读者我要写书评

暂无评论

Numerical Study on Benchmark Analysis of NACIE-UP Facility with Uniform and Non-Uniform power Distribution

SSRN

引用

SSRN 2024年

作者： Li, Haoyang Zhang, Dalin Zhou, Lei Deng, Jian Tian, Wenxi Su, Guanghui Qiu, Suizheng 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’an710049 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

The NACIE-UP facility is located at the ENEA Brasimone Research Centre and is designed to investigate the thermo-hydraulic properties of LBE within a wire-spaced assembly under uniform and non-uniform power distribution conditions. In this study, the thermo-hydraulic characteristics of FPS are analyzed. ANSYS Fluent solver is applied with the COUPLE algorithm of RANS [[EQUATION]] model. Cheng&Tak correlation and computational conditions are implanted into Fluent in the form of UDFs. The results show that the RMSEs of ADP10SS1 and ADP10SS2 are 2.52 K and 3.69 K, 7.05 K and 8.48 K for ADP06SS1 and ADP06SS2, respectively, which indicate that the adopted models have good prediction ability for the temperature of the experimental conditions. Meanwhile, the heat transfer characteristics are investigated and compared with the correlations of Ushakov, Mikityuk, Kazimi and Carelli. Above all, this study provides quantitative and qualitative analysis for verification and validation of CFD/STH code and stand-alone CFD simulation. © 2024, The Authors. All rights reserved.

关键词： Heat transfer

来源：评论

学校读者我要写书评

暂无评论

Evaluation of a Numerical Model for Predicting flow and Heat Transfer in a Hexagonal Helical Cruciform Seven-Rods Bundle and Analysis of Rod Bundle Size Independence

SSRN

引用

SSRN 2024年

作者： Jiang, Dianqiang Deng, Jian Zhang, Dalin Zhou, Xingguang Xiao, Changzhi Tian, Wenxi Qiu, Suizheng Su, Guanghui H. 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’an710049 China Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu610213 China China Institute of Atomic Energy Beijing611731 China

In this study, the accuracy and applicability of the numerical model are comprehensively evaluated based on the experimental data of a hexagonal helical cruciform (HC) seven-rods bundle. The STAR CCM+ is utilized as a tool to obtain predicted results of flow and heat transfer in different flow regions. The numerical results indicate that it is an improved method to set a negative heat flux on the hexagonal wall in the laminar flow region. The Reynolds stress transport model can accurately predict the experimental results of heat transfer in the transitional flow region, with an average wall temperature deviation of 2.8℃. The SST k-ω model with cubic constitutive option can accurately predict the experimental results of the flow resistance, and a relative error of f is 1.8%. In the turbulent flow region, the SST k-ω model with cubic constitutive option provides an accurate prediction, with an average wall temperature deviation of 3.7℃. The realizable k-Ε two-layer model can accurately predict the flow resistance, and the relative error of f is 0.1%. The preferred numerical model is used to analyze the size independence of the HC rod bundle. This work provides certain guidelines for the accurate simulation in the HC seven-rods bundle. © 2024, 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

Connectivity control of effective sorption capacity and kinetics in heterogeneous porous media

Connectivity control of effective sorption capacity and kine...

引用

第一届全国水处理与回用学术会议

作者： Li Wang Hang Wen Li Li Department of Environmental Science and Engineering State Key Laboratory of Multiphase Flow in Power Department of Energy and Mineral Engineering Penn State UniversityUniversity ParkPA 16802USA Department of Civil and Environmental Engineering Penn State UniversityUniversity ParkPA 16802USA

This work examines the effects of spatial heterogeneity in regulating Cr(Ⅵ)sorption under different geostatistical characteristics and spatial scale *** flow-through experiments in heterogeneous columns of 0.1 meters have shown that sorption in heterogeneous media can be characterized by three effective quantities: sorption capacity(Csc,m),early-stage fast sorption rate(kc1),and late-stage slow sorption rate(kc2).Two-dimensional reactive transport models are developed by calibrating these data from these columns of different illite distribution patterns and permeability contrasts between illite and quartz *** models were further run in geostatistical fields of different permeability variance(σ2lnκ,0.2 and 4.5)and length scale(0.1 to 1.0 m)conditions to quantify their role in determining effective sorption capacity and *** results indicate that in highly-connected columns with high permeability variance and long s,Cr(Ⅵ)-containing flow travels mostly through the high permeability,non-sorbing quartz *** therefore occurs mostly at the illite-quartz *** capacity and early fast rates(kc1)therefore depend strongly on the connectivity and properties that control advective transport of the *** longer time scales,diffusive transport determines the late-stage slow rates(kc2)and the breakthrough tailing,which depend less on connectivity and more on the size of the low-permeability illite zones and transverse dispersivity α*** to homogeneous columns of the same illite content,highly-connected patterns can reduce effective sorption capacity by up to a factor of 6.7,fast sorption rates by a factor of 25.0,and slow sorption rate by a factor of more than 2.0 orders of *** the domain length increases,the effects of spatial heterogeneities on sorption capacity and early stage fast sorption rates diminish due to longer length scales for mixing;these effects however persist for the late-stage slow sorp

关键词： connectivity sorption capacity spatial heterogeneity length scales reactive transport modeling

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：