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A dual-parameter measuring method for wet steam based on the characteristics of differential pressure under phase-isolation state

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flow MEASUREMENT AND INSTRUMENTATION 2023年第1期93卷

作者： Bian, Hanqing Qi, Xiaobing Liao, Ruiquan Wang, Dong Liu, Ming Yang, Weixia Zhang, Xingkai Yangtze Univ Sch Petr Engn Wuhan 430100 Peoples R China Yangtze Univ Hubei Key Lab Drilling & Prod Engn Oil & Gas Wuhan 430100 Peoples R China PetroChina Tarim Oilfield Co Oil & Gas Engn Res Inst Korla 84100 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Sinopec Shengli Oilfield Co Petr Engn Technol Res Inst Dongying 257000 Peoples R China Jinchang PetroChina Kunlun Gas Co Ltd Jinchang 737100 Peoples R China Yangtze Univ Petr Engn Inst Wuhan 430100 Peoples R China

To achieve accurate measurement of steam injection volume in the process of steam-driving heavy oil, a low-cost online metering device for wet steam flows is urgently needed. Primarily, the traditional Venturi device has a relative error due to the wet steam flow patterns. Therefore, a new physical model for wet steam measurement composed of a swirler and a Venturi was designed, based on the phase-isolation technology for multi-phase flow measurement. A theoretical explanation of the differential pressures was then proposed. Numerical simulations were conducted to investigate wet steam measurement, specifically under the condition of 10 similar to 20 MPa. A new correlation for the steam quality and mass flow rate with the pressure drop was developed by the multiphase flow model via Eulerian. A novel wet steam dual-differential pressure measurement model was established by considering the effects of temperature and pressure, which predicts the wet steam overall mass flow rate and steam quality of the measurement device. Block P601 and Block P6 of the oilfield located in eastern China were selected as the development test area, and the differential pressure prediction was carried out for 68 different working conditions of two Wells based on the dual-parameter measurement model, which was then calibrated. The experimental fieldwork on Block P601 demonstrated that the feasibility of the dual-parameter measuring method was verified, with relative deviations of +/- 7% between the predicted and experimental values of differential pressure. After calibration of the measurement model, the predicted values were compared with the experimental values, yielding relative deviations of +/- 3.5% and +/- 5% for mass flow rate and steam mass measured online for wet steam, with Mean Absolute Percentage Errors (MAPE) of 1.73% and 2.21%. Thus, the dual-parameter measuring method has a certain engineering significance for the steam injection technology of heavy oil in oilfields.

关键词： Wet steam measurement Phase-isolation Dual-parameter measurement Differential pressure Numerical simulation

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Current achievements on bubble dynamics analysis using MPS method

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PROGRESS IN NUCLEAR ENERGY 2020年 118卷 103057-000页

作者： Chen, Ronghua Dong, Chunhui Guo, Kailun Tian, Wenxi Qiu, Suizheng Su, G. H. Xi An Jiao Tong Univ Sch Nucl Sci & Technol Shaanxi Key Lab Adv Nucl Energy & Technol State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

Bubble dynamics always exist in nuclear reactor system which affect the fluid flow, heat transfer and moderation of neutrons. Therefore it is necessary to do some related researches that can be of significance to the nuclear engineering. With the aim to achieve better bubble dynamics simulations, a sequence of direct numerical simulation methods have been proposed in recent years. Specifically, as a fully Lagrangian method, the Moving Particle Semi-implicit (MPS) method has the capability to accurately track the interface. The bubble dynamics is one of the important benchmarks for testing the capability in the simulation of multiphase flow using MPS method. Due to the discontinuity of interface properties such as density, viscosity, it is a great challenge to simulate bubble dynamics with actual properties by MPS method. In view of this, this article carries on a comprehensive review and the summarization to the current researches in the basic models of the original MPS method and the modified MPS methods for bubble dynamics, and proposes the future perspectives in this field. Meantime, the characteristics of different modified MPS methods are also discussed in detail by the comparison of the corresponding simulation results. To sum up, this article could provide ideas for further improvements of MPS method and promote its applications in the field of nuclear engineering.

关键词： Bubble dynamics Numerical simulation Moving particle semi-implicit (MPS) method Modified method

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Sustainable hydrogen production from coal tar residue via supercritical water gasification

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Journal of Cleaner Production 2025年 519卷

作者： Jingui Bai Yu Wang Shi Liu Libo Lu Wen Cao Ting Chen Yunan Chen Liejin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University No.28 Xianning West Road Xi'an 710049 China Ningxia Baoting New Materials Technology Co. Ltd. Yinchuan 751400 Ningxia China

Hazardous wastes such as coal tar residue (CTR) pose a serious hazard to the environment and human health. In the context of ‘carbon peak and carbon neutrality’, the conversion of wasted resources into energy to replace fossil fuels is in line with the requirements of future social development. Supercritical water (SCW) offers a promising approach for converting hazardous waste CTR into energy. This article combines supercritical water gasification (SCWG) technology with the efficient utilization of CTR for the first time, providing a scientific solution for reducing environmental pollution and preparing hydrogen. In this article, we systematically investigated the effects of temperature (540–700 °C), residence time (5–60 min), material concentration (3 wt%-11 wt%), and six different catalysts on CTR SCWG. Experimental results indicate that higher temperature, longer reaction time, and lower CTR concentration are beneficial for gasification. When the temperature, retention time, material concentration, and catalyst are set at 700 °C, 60 min, 3 wt%, and K 2 CO 3 respectively, most of the carbon in the CTR is converted into small molecular gases. The carbon gasification efficiency (CE) reaches 94.44 %, while the H 2 yield attains a value of 67.56 mol kg −1 . Finally, based on the analysis results of gas, liquid and solid products, the SCWG mechanism of CTR is summarized.

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Effects of water leaching (simulated rainfall) and additives (KOH, KCl, and SiO2) on the ash fusion characteristics of corn straw

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APPLIED THERMAL engineering 2019年 154卷 485-492页

作者： Niu, Yanqing Lv, Yuan Zhang, Xiao Wang, Denghui Li, Ping Hui, Shi'en Xi An Jiao Tong Univ Sch Energy & Power Engn Dept Thermal Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Ningxia Univ Coll Chem & Chem Engn State Key Lab High Efficiency Utilizat Coal & Gre Yinchuan 750021 Peoples R China

To solve the intractable slagging problem during biomass combustion, natural leaching by rainfall is an economy and effective post-harvest quality optimization method. The effects of simulated rainfall intensity and duration on the removals of ash, K and Cl, and consequently the ash fusion temperature (AFTs) of corn straw were studied. Meanwhile, the effects of KOH, KCl, and SiO2 additives were compared. Leaching reduced the formation of KCl and K2SO4 in biomass ash effectively and thus the formation of low-melting K2O center dot nSiO(2) (n = 1-4), whereas the relatively content of high-melting SiO2 increased, resulting in increased AFTs. Leaching intensity had stronger effects than leaching duration. There exists a critical leaching point at similar to 4 ml water consumption per gram biomass, after which continued leaching had less removal efficiencies. During the initial leaching stage (with a water consumption of 2-4 ml per gram biomass), less removal of Cl compared to K2O caused lower IDT and ST, but higher FT;consequently, the extended temperature difference deteriorates deposition formation. A raninfall/snow leaching influencing mechanism on biomass AFTs was illustrated. These results provide useful guidelines for choosing the appropriate time node of straw collection in field based on rainfall, and thus reducing slagging during biomass combustion.

关键词： Biomass Ash fusion Leaching Additive Simulated rainfall

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Full-scale numerical study on the thermal-hydraulic characteristics of steam-water separation system in an advanced PWR UTSG. Part two: Droplets separation process

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PROGRESS IN NUCLEAR ENERGY 2020年 118卷 103139-000页

作者： Fang, Di Li, Linfeng Li, Jun Wang, Mingjun Yu, Hao Zhang, Jing Qiu, Suizheng Tian, Wenxi Su, G. H. Xi An Jiao Tong Univ Shaanxi Key Lab Adv Nucl Energy & Technol Sch Nucl Sci & Technol State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

Performance of the separation system in the UTSG determines the quality of supplied steam in a nuclear power plant. In the present study, the Eulerian-Lagrangian methodology is applied in a full-scale UTSG separation system of GEN-III China advanced PWR. Detailed flow characteristics and separation performance of the whole system are investigated. Effects of the steam velocity and droplets sizes on the separation process are also discussed. Last but not least, the mal-distribution phenomena in dryers are analyzed. Results illustrate that the separators at the hot side have a better performance than the ones at the cold side, and the separation efficiency falls within the range from 98.16% to 99.39% in the current system. What's more, both the steam velocity and the droplets radii have obvious effects on the separation performance. For dryers, obvious mal-distribution phenomena are estimated. As a result of the lower efficiency of separators at cold side, the #7 dryer suffers the maximum loading of entrained water on unit-area (1.24kg/(m(2).s)), and the greatest humidity at entrances of dryers is observed to be 4.90% accordingly. In general, the present work could be expected to be the assessment and basis of UTSG separation system optimization for China advanced PWR.

关键词： Separation system CFD Full-scale analysis Eulerian-Lagrangian methodology

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Performance of Low-temperature SCR of NO with NH3 over MnOx/Ti-based catalysts

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CANADIAN JOURNAL OF CHEMICAL engineering 2019年第Sup1期97卷 1407-1417页

作者： Niu, Yanqing Zhang, Xiaolu Zhang, Hao Liang, Yang Li, Shuaifei Yao, Qi Wang, Denghui Hui, Shi'en Xi An Jiao Tong Univ Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China North China Elect Power Sci Res Inst Co Ltd Beijing 10045 Peoples R China

The effects of Mn loadings and precursors, catalyst preparation methods, incineration durations and temperatures, and the addition of Co and Ce on NO-reduction efficiency and selectivity (N2O formation) during the preparation of MnOx/Ti-based catalysts were studied by micropore-size analysis (XRD, XPS, SEM, and FTIR), while considering changeable parameters. Meanwhile, the performance of low-temperature SCR of NO with NH3 over the designed catalysts was tested under various gas hourly space velocities (GHSVs), NH3/NO molar ratios, and contents of NO, NH3, O-2, H2O, and SO2 in a lab-scale reactor. Overall, the Mn(0.3)Ce(0.1)/Ti catalyst, which had high NO-reduction efficiency and selectivity (low N2O formation), was recommended, with the following preparation methods: ultrasonic impregnation;manganese acetate precursor;and incineration at 500 degrees C. Appropriate textural properties (high surface area and small pore and crystallite sizes), well-dispersed amorphous manganese (rather than crystalline) on the anatase surface (rather than rutile), abundant active sites, and long residence time are essential for high NO-reduction efficiency. In practice, NO-reduction efficiency decreased with increasing GHSV and the NH3 and NO contents;however, it initially increased and then became saturated with an increasing NH3/NO molar ratio and O-2 content. Water deactivated the catalyst to a recoverable state, whereas SO2 resulted in unrecoverable deactivation.

关键词： low-temperature SCR MnOx/Ti NO N2O NH3

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LES and URANS study on turbulent flow through 3 x 3 rod bundle with spacer grid and mixing vanes using spectral element method

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ANNALS OF NUCLEAR ENERGY 2021年 161卷 108474-108474页

作者： Ju, Haoran Yu, Hao Wang, Mingjun Zhao, Minfu Tian, Wenxi Liu, Tiancai Su, G. H. Qiu, Suizheng Xi An Jiao Tong Univ Sch Nucl Sci & Technol State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China China Inst Atom Energy POB 275-59 Beijing 102413 Peoples R China Royal Inst Technol KTH Div Nucl Power Safety Roslagstullsbacken 21 S-10691 Stockholm Sweden

In this paper, the turbulent flow in rod bundles with spacer grid and mixing vanes in nuclear reactor core was studied using spectral element method with large eddy simulation (LES) and unsteady RANS (URANS) method. Combining with the radial periodical boundary conditions, the turbulent mixing phenomena in central subchannels were investigated, especially focusing on the flow field after the spacer grid and mixing vanes. Other than setting up long bare rod bundle to establish the fully developed turbulent flow, only a 2-cm-long bare rod bundle was extruded upstream the spacer grid and mixing vanes, while the fully developed laminar velocity profile was applied on the inlet surface for velocity boundary settings. The results indicate that both of the models could predict time-averaged velocity at 0.5Dh, 1Dh, 4Dh downstream mixing vanes properly, while the URANS model underestimate the root-mean-square (RMS) value of fluctuating velocity due to the inlet treatment effect. Furthermore, turbulent kinetic energy contour with transverse velocity vector was combined to investigate the behaviors of vortices formed by split-type mixing vanes, revealing the behavior of vortices for preliminary dynamic and mechanic analysis in design process of fuel assembly. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Turbulent mixing LES URANS Spectral element method CFD validation

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Thermal characteristics and thermal stress analysis of a superheated water/steam solar cavity receiver under non-uniform concentrated solar irradiation

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APPLIED THERMAL engineering 2021年第Part2期183卷 116234-116234页

作者： Fang, Jiabin Zhang, Canghong Tu, Nan Wei, Jinjia Wan, Zhenjie Xi An Jiao Tong Univ Sch Chem Engn & Technol Xian 710049 Peoples R China Xian Polytech Univ Sch Mech & Elect Engn Xian 710048 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China

Solar cavity receiver is a vital component in a solar power tower (SPT) system, where concentrated solar irradiation is absorbed, converted into heat and carried away by a kind of heat transfer fluid. The cavity receiver usually suffers from the high-flux and non-uniform concentrated solar irradiation, which would cause local overheating, large temperature gradient and even thermal stress fracture of the receiver and bring challenges for the safety of its daily operation. Therefore, it is necessary to investigate the thermal and mechanical performance of the solar cavity receiver. In the present study, a superheated water/steam solar cavity receiver with three boiling panels and a superheater was chosen as the physical model. An integrated simulation method, which couples the Monte-Carlo ray tracing (MCRT) method, the appropriate heat transfer correlations, the finite volume method (FVM) and the finite element method (FEM), was employed to simulate the complicated heat transfer process inside the receiver and conduct the thermal stress analysis for the absorber panels. With this method, the three-dimensional wall temperature and thermal stress distributions were gained both on the boiling panels and the superheater, and the causes of thermal stress induced by different temperature gradients were analyzed in detail. The following results were obtained: 1) The heat flux, wall temperature and equivalent thermal stress distributions all appear highly non-uniform on the absorber panels;2) The hot spots can be found on the membrane wall between the elbows of the boiling panels, which can easily generate the high thermal stress due to the large temperature gradient with their surroundings;3) The bi-axial stress at the outer and inner radius of the boiling tubes can be created by the large radial temperature gradient, and the thermal stress varies as a cosine distribution across the circumference of the superheated tubes, which is induced by the large temperature gradient i

关键词： Solar cavity receiver Boiling panels Superheater Temperature gradient Thermal stress

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Ion Migration as a New Paradigm to Boost Self-Driven Perovskite Narrowband Photodetectors

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ADVANCED OPTICAL MATERIALS 2023年第16期11卷

作者： Yu, Shanshan Li, Yu Wang, Jian Zhang, Kai Lin, Zedong Qian, Wei Deng, Ziqi Guo, Fumin Li, Mingde Vayssieres, Lionel Saidaminov, Makhsud I. Phillips, David Lee Yang, Shihe Peking Univ Sch Chem Biol & Biotechnol Shenzhen Grad Sch Guangdong Prov Key Lab Nanomicro Mat Res Shenzhen 518055 Peoples R China Inst Biomed Engn Shenzhen Bay Lab Shenzhen 518107 Peoples R China Univ Hong Kong Dept Chem Hong Kong 999077 Peoples R China South China Agr Univ Coll Mat & Energy Guangzhou 510642 Peoples R China Shantou Univ Dept Chem Shantou 515063 Peoples R China Shantou Univ Key Lab Preparat & Applicat Ordered Struct Mat Gua Shantou 515063 Peoples R China Xi An Jiao Tong Univ Int Res Ctr Renewable Energy IRCRE Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Univ Victoria Dept Chem 3800 Finnerty Rd Victoria BC V8P 5C2 Canada

Halide perovskite narrowband photodetectors based on a charge collection narrowing mechanism have emerged as a new class of optoelectronic devices for monochromatic imaging. However, improving the figures-of-merit of such narrowband photodetectors remains challenging due to the inability to manipulate the major material players in the elusive photoresponse process. Here, a novel approach of manipulating ion migration to enhance the narrowband photoresponse of self-driven p-i-n type photodetectors is taken by intentionally adding mobile ions into the formamidine and methylamine mixed cation perovskite layer. The excess mobile ions reduce the activation energy of ion migration, and this facilitated migration orchestrates the ions in the perovskite layer to re-engineer the energy band, and thus modulates the charge separation and collection energetics and kinetics, leading to an unprecedented boost of the narrowband photoresponse. The photodetector based on this approach achieved a peak responsivity of as high as 112.41 mA W-1 at 820 nm at zero bias with a full-width at half maximum of only 22 nm and an over 3-fold improvement in the spectral rejection ratio, making it highly promising for the next-generation color imaging devices.

关键词： ion migration narrowband response perovskites photodetectors quantum efficiency

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Revealing the unexpected promotion effect of diverse potassium precursors on α-MnO2 for the catalytic destruction of toluene

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CATALYSIS SCIENCE & TECHNOLOGY 2020年第7期10卷 2100-2110页

作者： Zhu, Qing Jiang, Zeyu Ma, Mudi He, Chi Yu, Yanke Liu, Xiaohe Albilali, Reem Xi An Jiao Tong Univ Dept Environm Sci & Engn State Key Lab Multiphase Flow Power Engn Sch Energy & Power Engn Xian 710049 Shaanxi Peoples R China Univ Chinese Acad Sci Natl Engn Lab VOCs Pollut Control Mat & Technol Beijing 101408 Peoples R China Columbia Univ Dept Chem Engn New York NY 10027 USA Imam Abdulrahman Bin Faisal Univ Dept Chem Coll Sci POB 1982 Dammam 31441 Saudi Arabia

The alkali metal potassium has the functions of structure promotion and electronic modulation in metal oxides. Herein, diverse potassium precursors (KOH, KNO3, K2SO4, and KCl) were introduced to alpha-MnO2 nanorods through a facile post-processing strategy. The presence of potassium species has a remarkable promotion effect on the catalytic performance of alpha-MnO2. Amongst them, the KOH/MnO2 sample has the highest activity and can destroy 90% toluene (1000 ppm) at just 226 degrees C with a reaction rate of 3.39 x 10(-4) mol g(cat)(-1) s(-1), which is over 20 times higher than that of pure alpha-MnO2. Different anions in the potassium precursors bring a distinct mutation in the alpha-MnO2 structure, promote the formation of MnO6-K-MnO6 bridging bonds in alpha-MnO2, and exhibit obvious diverse abilities for balancing charge transfer. KOH is identified as the most promising precursor for alkali metal modification, which significantly improves the distribution of K species over the alpha-MnO2 surface and strengthens the content and activity of lattice oxygen. It is confirmed that the lattice oxygen plays a key role in the catalytic oxidation of toluene over alpha-MnO2, which follows the Mars-van Krevelen mechanism. Positive hole defects (Mn3+) caused by KOH treatment play an important role in the diffusion of O and enhance the reducibility of manganese oxide. In addition, the enhanced specific surface area, pore volume, and surface acidity are also conducive for the catalytic oxidation of toluene.

关键词： Nanorods

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