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Experimental Investigation on Enhanced Oil Recovery of Extra Heavy Oil by Supercritical Water Flooding

ENERGY & FUELS 2018年第2期32卷 1685-1692页

作者： Zhao, Qiuyang Guo, Liejin Huang, Zujie Chen, Lei Jin, Hui Wang, Yechun Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

Exploitation of deep extra heavy oil is a challenging work due to its high viscosity and high reservoir pressure. Supercritical water is first proposed as an injection agent, considering its favorable physiochemical properties. A novel flooding experimental system with a design temperature up to 450 degrees C and pressure up to 30 MPa was developed to demonstrate the feasibility of supercritical water flooding (SCWF) technology. A sand pack core with an adiabatic boundary was used to eliminate heat unbalance. The experimental results indicated that SCWF is a promising enhanced oil recovery technology. SCWF could significantly enhance oil recovery when compared with steam flooding and hot water flooding and reduce the oil viscosity simultaneously. SCWF at 25 MPa and 400 degrees C raised the recovery efficiency to 97.07% and reduced oil viscosity by 36.9%. The mechanism is attributed to the extraction heavy oil components into the water-rich phase by supercritical water and the formation of miscible flooding.

关键词： Enhanced oil recovery supercritical water Oil recovery heavy oil Flood oil viscosity RECOVERY EFFICIENCY MISCIBLE DRIVE design temperature

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POOL BOILING EXPERIMENT ON A MODIFIED MICROPIN-FINNED SURFACE WITH MECHANICAL OSCILLATION

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HEAT TRANSFER RESEARCH 2018年第11期49卷 991-1001页

作者： Wei, Jinjia Kong, Xin Ding, Jie Zhang, Yonghai Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

To further enhance pool boiling heat transfer, a new oscillation device was proposed. An oscillating plate was located over the heater surface with a vertical oscillation amplitude of 20 mm and frequency of 6 Hz. Three N-type phosphorus-doped silicon chips were used as heater surfaces. One was a smooth surface, and the other two were micropin-finned chips with a fin side length of 30 mu m and fin height of 60 mu m (chip PF30-60), and the pin fins were arrayed with aligned and staggered arrangements, respectively. Absolute ethyl alcohol was used as a working fluid. The results showed that mechanical oscillation can enhance boiling heat transfer in both convective region and high heat flux region. The wall superheat showed a considerable decrease of 20-30 degrees C in the convective region by thinning the thermal boundary layer on the heater surface, and the critical heat flux could also be increased by 20%. In addition, the micropin-finned chips showed better performance due to much more fresh liquid supply from the interconnected tunnels formed by micropin fins, which is driven by capillary force.

关键词： micropin fin oscillation boiling heat transfer

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Investigation of the fuel effects on burning velocity and flame structure of turbulent premixed flames based on leading points concept

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COMBUSTION SCIENCE AND TECHNOLOGY 2018年第8期190卷 1354-1376页

作者： Zhang, Weijie Wang, Jinhua Yu, Qianqian Jin, Wu Zhang, Meng Huang, Zuohua Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

The measurements on flame structure and burning velocities of C3H8/air, CH4/air and CO/H-2/air turbulent premixed flames were conducted. Various experimental conditions for these mixtures were considered to understand the molecular and thermal diffusion process in turbulent flame, which was referred to the fuel effects. The fuel effects are interpreted as local burning velocity variation caused by molecular and thermal diffusivity with stretch effect. Leading points concept is a promising scaling approach to incorporate the fuel effects in turbulent flames recently. In this article, data across a variety of equivalence ratio and hydrogen fractions were obtained using Bunsen burner. Flame front was detected with OH-PLIF technique and turbulent burning velocity S-T referred to leading edge was derived. A new leading points characteristic speed S-L,S-LP was presented invoking both negative and positive Markstein number mixtures, revising the previous model in literature which is only suitable for negative Markstein number fuels. The turbulent burning velocity S-T under relatively weak turbulence intensity in this study and data of high turbulence intensity, high pressure from literature were renormalized with S-L,S-LP instead of S-L,S-0 based on leading points concept, where S-L,S-0 is the unstretched laminar flame speed. The results show that all the data sets were collapsed well which validated the significance of S-L,S-LP in normalizing S-T of different mixtures. An empirical formula for turbulent burning velocity correlation was obtained as. This formula is similar to that of Kobayashi;however, it shows superiority in incorporating the fuel effects.

关键词： Turbulent burning velocity turbulent premixed flame leading points concept fuel effects

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Characteristics of bubble, cloud and wake in jetting fluidised bed determined using a capacitance probe

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CHEMICAL engineering RESEARCH & DESIGN 2018年 136卷 687-697页

作者： Huang, Jikai Lu, Youjun Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

Detailed properties of bubble, cloud and wake in a jetting fluidised bed are studied by a capacitance probe method in this paper. In a jetting fluidized bed, when smaller particles are fluidised, bubble size and rising velocity initially increase near the distributer and maintains almost constant values with the increase in bed height. When bigger particles are fluidized, the bubble size and rising velocity decreased with the increase in bed height. The bubbles in bed when bigger particles are fluidised are smaller than those when smaller particles are fluidised under the same operating conditions. Background gas velocity has a more significant influence on bubble size, whereas the jetting gas velocity has a more significant influence on bubble rising velocity. The effect of operating conditions and bubble size on the averaged voidage of cloud or wake is negligible. Besides, the thickness of cloud and wake increases with bubble size, and the thickness of cloud is greater than that of wake. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Jetting fluidized bed Bubble dynamics Cloud and wake Capacitance probe

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Significantly enhanced electrostatic energy storage performance of P (VDF-HFP)/BaTiO3-Bi(Li0.5Nb0.5)O3 nanocomposites

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NANO ENERGY 2020年 78卷

作者： Wang, Peng-Jian Zhou, Di Li, Jing Pang, Li-Xia Liu, Wen-Feng Su, Jin-Zhan Singh, Charanjeet Trukhanov, Sergei Trukhanov, Alex Xi An Jiao Tong Univ Elect Mat Res Lab & Multifunct Mat & Struct Key Lab Minist Educ Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Int Ctr Dielect Res Sch Elect Sci & Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Xian 710049 Shaanxi Peoples R China Xian Technol Univ Microoptoelect Syst Labs Xian 710032 Shaanxi Peoples R China Xi An Jiao Tong Univ Int Res Ctr Renewable Energy State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Lovely Profess Univ Sch Elect & Commun Engn Jalandhar Punjab India Natl Univ Sci & Technol MISiS Leninskii Av 4 Moscow 4119049 Russia South Ural State Univ Lenin Av 76 Chelyabinsk 454080 Russia NAS Belarus Sci & Pract Mat Res Ctr P Brovki Str 19 Minsk 220072 BELARUS

Microelectronics and electrical power systems require dielectric polymer-based dielectrics with high energy density that are simple to process. However, the currently available polymer-based dielectric materials require demanding process conditions and relatively low energy density. Herein, we propose P(VDF-HFP)-based nano composite by a simple and practical mechanical method based on a combination of solid phase reaction and sieving to prepare 0.88BaTiO(3)-0.12Bi(Li0.5Nb0.5)O-3 nanoparticles (BT-BLN nps). The experimental and simulation result verify that the BT-BLN nps significantly improve the breakdown strength and energy storage performance of dielectric materials. Remarkably, the highest discharge energy density of the BT-BLN/P(VDF-HFP) nanocomposite film reached 14.2 J/cm(3) with the addition of 3 vol% BT-BLN nanofiller at 497 MV/m, which is much higher than that of pure P(VDFHFP) (Ud approximate to 6.6 J/cm(3) and Eb approximate to 391.3 MV/m). Encouragingly, the Young's modulus of BLN-3vol%/P(VDF-HFP) reached 2.6 GPa, which is approximately 2.65 times higher than that of pure P(VDF-HFP) (0.98 GPa). This work established a simple and effective strategy, for solution casting processable dielectrics with performance comparable to that of fillers prepared by the liquid phase method.

关键词： Nanocomposite BaTiO3-Bi(Li0.5Nb0.5)O-3 Breakdown strength Energy storage

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Ultrahigh enhancement rate of the energy density of flexible polymer nanocomposites using core-shell BaTiO3@MgO structures as the filler

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JOURNAL OF MATERIALS CHEMISTRY A 2020年第22期8卷 11124-11132页

作者： Wang, Peng-Jian Zhou, Di Guo, Huan-Huan Liu, Wen-Feng Su, Jin-Zhan Fu, Mao-Sen Singh, Charanjeet Trukhanov, Sergei Trukhanov, Alex Xi An Jiao Tong Univ Sch Elect Sci & Engn Elect Mat Res LabMinist Educ Multifunct Mat & StructKey LabInt Ctr Dielect R Xian 710049 Peoples R China Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Int Res Ctr Renewable Energy State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Northwestern Polytech Univ Sch Mat Sci & Engn Shaanxi Mat Anal & Res Ctr Xian 710072 Shaanxi Peoples R China Lovely Profess Univ Sch Elect & Commun Engn Jalandhar Punjab India Natl Univ Sci & Technol MISiS Leninskii Ave 4 Moscow 4119049 Russia South Ural State Univ Lenin Ave 76 Chelyabinsk 454080 Russia NAS Belarus Sci & Pract Mat Res Ctr P Brovki Str 19 Minsk 220072 BELARUS

Dielectric energy storage capacitors are critical components widely used in electronic equipment and power systems due to their advantages of ultrahigh power density and high voltage. Herein, a novel core-shell BaTiO3@MgO (BT@MO) nanostructure was fabricated, in which highly insulating MgO was directly coated on a continuous ferroelectric nanoparticle BaTiO(3)shell through a chemical precipitation method to improve the breakdown strength and electric displacement under high electric field. A large electric displacement (D approximate to 9.8 mu C cm(-2)under 571.4 MV m(-1)) was observed along with a high discharge energy density (Ud approximate to 19.0 J cm(-3)) for BT@MO/P(VDF-HFP) composites, which was 187% higher than that for a P(VDF-HFP) film when the filler content was 3 wt%. The enhancement rate ofU(d)in this study achieved the highest level among the reported results. It was revealed that the highly insulating MgO shell can enhance the breakdown strength by preventing charge injection from electrodes and impeding the development of electrical stress during the breakdown process, as confirmed by the leakage current measurements and the finite element simulations. The core-shell BT@MO structured filler provided an effective way to improve the energy storage properties of the polymer-based dielectrics.

关键词： Magnesia

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Increasing operational flexibility of supercritical coal-fired power plants by regulating thermal system configuration during transient processes

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APPLIED ENERGY 2018年 228卷 2375-2386页

作者： Zhao, Yongliang Liu, Ming Wang, Chaoyang Li, Xin Chong, Daotong Yan, Junjie Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

The operational flexibility of traditional coal-fired power generators has played crucial parts in many countries given the continuous integration of intermittent and fluctuant renewable power resources in their power system. This study is aimed at improving the short-term operational flexibility of thermal power units. The transient simulation models of a 660 MW supercritical coal-fired power system are developed by using the GSE software, and the six measures of regulating thermal system configuration, which can rapidly activate thermal storages in thermal systems, are introduced and compared. The greatest potential mode in each measure of regulating thermal system configuration is obtained on the basis of the utilization degree of the internal thermal storages. The dynamic characteristics of the thermal parameters of the selected measures are compared, and the results reveal that the measures of regulating extraction steam from low-pressure heaters has less negative effects on the live and reheat steam parameters but greater negative effects on the deaerator and condenser parameters than the measures of regulating extraction steam from high-pressure heaters. Moreover, the performance indexes of operational flexibility are also evaluated for all the measures of regulating thermal system configuration. Among five measures applied in the power-up process, the values of power ramp rate are from 1.26% to 6.31% of rated power per minute, the values of power capacity are from 12.87 to 48.35 MW, and the values of energy capacity during the regulating time of 120 s are 1009.73 to 5048.93 MJ. However, the measure of condensate water increasing of low-pressure heaters is an only way suitable for the power-down regulation process, and the value of power ramp rate is 0.61% of rated power per minute, the power capacity is -5.65 MW, and the energy capacity is -483.84 MJ. The best regulating measures are obtained on the basis of the different perspectives of operational flexibil

关键词： Operational flexibility Transient simulation Thermal system configuration Thermal power plant

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The real-time investigation of the nickel-iron hydroxide catalyzed oxygen evolution reaction with interdigitated array electrodes

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NANOTECHNOLOGY 2021年第37期32卷 375706-375706页

作者： Liu, Fei Zhang, Jie Wu, Weiwei Zhang, Peng Ma, Xiaohua Tao, keyu Wang, Tongtong Wang, Qi Xidian Univ Interdisciplinary Res Ctr Smart Sensing Sch Adv Mat & Nanotechnol Xian 710126 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn MFPE Int Res Ctr Renewable Energy IRCRE 28 West Xianning Rd Xian 710049 Peoples R China Xidian Univ Sch Microelect Xian 710126 Shaanxi Peoples R China

Electrocatalysis of oxygen evolution reaction (OER), one of the most important members in clean and efficient energy conversion, requires increasing studies on reaction process analysis, catalyst investigation and evaluation and so on through in situ experiments. The bottleneck is the difficulties on clear and precise understanding towards the multi-step reactions with fast reaction rates. Interdigitated array (IDA) electrodes with sensitive responses on the generation, transfer and collection of reaction products are proposed and utilized as a convenient and effective tool to in situ monitor and characterize the reaction thermodynamics and kinetics information. Herein, nickel-iron hydroxide, a promising and novel OER catalyst, is chosen as the candidate to demonstrate the merit of IDA on studying the OER. With the generator-collector mode, the real-time oxygen evolution process is monitored precisely with the IDA collector, distinguished it from the general catalytic current which is normally recorded with conventional electrochemical method. In another word, the actual faradaic efficiency was observed experimentally with IDA electrodes, which is often misled as 100% in many works. The diffusion of the reaction products has been 'seen' as well with the generator-collector mode. This general tool (IDA) may make more contributions on the study of reaction process of all electrocatalytical reactions.

关键词： interdigitated array electrodes NiFe oxygen evolution reaction electrocatalysis in situ

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An ultra-broadband terahertz metamaterial coherent absorber using multilayer electric ring resonator structures based on anti-reflection coating

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NANOSCALE 2020年第17期12卷 9769-9775页

作者： Du, Chao Zhou, Di Guo, Huan-Huan Pang, Yong-Qiang Shi, Hong-Yu Liu, Wen-Feng Su, Jin-Zhan Singh, Charanjeet Trukhanov, Sergei Trukhanov, Alex Panina, Larissa Xu, Zhuo Xi An Jiao Tong Univ Elect Mat Res Lab Key Lab Minist Educ Xian 710049 Peoples R China Xi An Jiao Tong Univ Int Ctr Dielect Res Sch Elect Sci & Engn Xian 710049 Peoples R China Xi An Jiao Tong Univ Sch Informat & Commun Engn Xian 710049 Peoples R China Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Int Res Ctr Renewable Energy State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Lovely Profess Univ Sch Elect & Commun Engn Jalandhar Punjab India Natl Univ Sci & Technol MISiS Leninskii Av 4 Moscow 4119049 Russia South Ural State Univ Lenin Av 76 Chelyabinsk 454080 Russia NAS Belarus Sci & Pract Mat Res Ctr P Brovki Str 19 Minsk 220072 BELARUS

We propose a method for achieving THz ultra-broadband coherent absorption using the anti-reflection theory of metamaterials. The metamaterial absorber consists of a periodic array of electric ring resonators with a multilayered structure which form the desired refractive index dispersion and provide continuous anti-reflection over a wide frequency range. The destructive interference mechanism and resonance absorption of the absorber are determined by simulation analysis and numerical simulation. Simulation results show that the absorption bandwidth is almost 8.02 THz (absorption rate >90%) over the entire terahertz band (0.1 THz-10 THz). This design provides an effective and viable method for constructing broadband absorbers for stealth technology and the construction of enhanced transmittance devices.

关键词： Metamaterials

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Thermal Hydraulic and Neutronics Coupling Analysis for Plate Type Fuel in Nuclear Reactor Core

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SCIENCE AND TECHNOLOGY OF NUCLEAR INSTALLATIONS 2020年第1期2020卷

作者： Ye, Linrong Wang, Mingjun Wang, Xin'an Deng, Jian Xiang, Yan Tian, Wenxi Qiu, Suizheng Su, G. H. Xi An Jiao Tong Univ Dept Nucl Sci & Technol State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Nucl Power Inst China Sci & Technol Reactor Syst Design Technol Lab Chengdu Peoples R China Royal Inst Technol KTH S-11428 Stockholm Sweden

The thermal hydraulic and neutronics coupling analysis is an important part of the high-fidelity simulation for nuclear reactor core. In this paper, a thermal hydraulic and neutronics coupling method was proposed for the plate type fuel reactor core based on the Fluent and Monte Carlo code. The coupling interface module was developed using the User Defined Function (UDF) in Fluent. The three-dimensional thermal hydraulic model and reactor core physics model were established using Fluent and Monte Carlo code for a typical plate type fuel assembly, respectively. Then, the thermal hydraulic and neutronics coupling analysis was performed using the developed coupling code. The simulation results with coupling and noncoupling analysis methods were compared to demonstrate the feasibility of coupling code, and it shows that the accuracy of the proposed coupling method is higher than that of the traditional method. Finally, the fuel assembly blockage accident was studied based on the coupling code. Under the inlet 30% blocked conditions, the maximum coolant temperature would increase around 20 degrees C, while the maximum fuel temperature rises about 30 degrees C. The developed coupling method provides an effective way for the plate type fuel reactor core high-fidelity analysis.

关键词： Hydraulic models

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