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SSRN 2022年

作者： Wu, Yingtao Wang, Zhi Fei, Lihan Guo, Yang Liu, Yang Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Research Center of Energetic Material Genome Science Institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The hypergolic ignition behaviors of [AMIM][DCA] (1-allyl-3-methylimidazolium dicyanamide)/furfuryl alcohol (FA) blends reacting with white fuming nitric acid (WFNA) are investigated using drop test approach. Morphology results from two high speed cameras and temperature profiles from an infrared camera are combined in analyzing the hypergolic process. A typical hypergolic process observed in this work involves a mixing dominant stage, a stage with moderate temperature rising and vapor/secondary droplets emerging, and a stage with violent temperature rising accompanied by flame occurrence. Two kinds of delay times are used to characterize the hypergolic process which are found to be nonmonotonic with the variations of FA fractions. FA, though not hypergolic with WFNA, exhibits extensive pre-ignition heat release due to its physical and chemical properties, which enhances the hypergolic process of [AMIM][DCA]/FA blends with WFNA. © 2022, The Authors. All rights reserved.

关键词： Ionic liquids

Waterside Corrosion of M5 Alloy in Simulated Primary Coolant and Supercritical Water: Influences of Aqueous Environments

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SSRN 2022年

作者： Jiang, Guanyu Liu, Lu Xu, Donghai Li, Yanhui Kuang, Wenjun Wang, Mingjun Key Laboratory of Thermo-Fluid Science & Engineering Ministry of Education School of Energy and Power Engineering Xi’an Jiaotong University Shaanxi Province Xi’an710049 China State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'An710049 China State Key Laboratory of Multiphase Flow in Power Engineering Department of Nuclear Science and Technology Xi'an Jiaotong University Xi'An China

M5 alloy is highly potential to serve as cladding materials in nuclear reactors. In this work, corrosion characteristics of M5 alloy in lithiated/borated water and pure supercritical water were investigated, and influences of aqueous environments on the corrosion process were clarified. Oxide films formed on the alloy mainly consisted of m-ZrO2. In the coolant environment, Li+ and OH- shared a synergistic effect on the occurrence and acceleration of waterside corrosion. Boric acid can react with OH- to induce B-(OH) formation and participate in the generation of zirconium borate to alleviate the accelerated corrosion effect by LiOH. In supercritical water, M5 alloy showed weight loss due to localized oxide exfoliation, and dissolved oxygen resulted in serious pitting of the oxide film. The microcrack density and porosity were significantly larger than those in the coolant environment, and long transverse cracks parallel to the O/M interface existed. Oxide deposition in two environments was both observed, and the phenomenon was discussed. © 2022, The Authors. All rights reserved.

关键词： Coolants

Study on the Catalytic Performance of Nano-Mesoporous Cobalt-Based Catalysts for Glycerol Dry Reforming

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SSRN 2022年

作者： Dou, Binlin Wang, Yadong Zhang, Hua Wu, Kai Ren, Ruijia Chen, Haisheng Xu, Yujie School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China

Dry reforming is an efficient utilization technology that can convert CO 2 into high-value-added syngas. In this work, nano-mesoporous CeO 2 -supported Co-based catalysts were successfully prepared by the colloidal solution combustion method and used in glycerol dry reforming (GDR) experiments. The characterization results show that the prepared catalyst has a uniform mesoporous structure, and the Co-Fe-Ce catalyst has a higher specific surface area and stronger metal-support interaction than the Co-Ce catalyst. Thermodynamic analysis was conducted using a non-stoichiometric method methodology based on Gibbs free energy minimization. Catalytic experiments were carried out at 650°C to 800°C. The results showed that the Co-Fe-Ce catalyst exhibited higher activity and selectivity in the GDR reaction, and the glycerol conversion of 7CoFeCe at 750 °C reached 84.8%. The 10 h stability experiment shows that the Fe promoter has a positive effect on the stability of the catalyst. The TPO results indicate that Fe doping can suppress filamentous carbon formation. © 2022, The Authors. All rights reserved.

关键词： Catalyst activity

Effect of the Density Difference on Fluid Distribution in Layered Rock Samples

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Energy & Fuels 2025年第9期39卷 4412-4420页

作者： Yongfei Yang Tonghui Liu Yingwen Li Weichen Sun Hai Sun Lei Zhang Junjie Zhong Kai Zhang Jun Yao State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) Qingdao 266580 P. R. China；Research Center of Multiphase Flow in Porous Media School of Petroleum Engineering China University of Petroleum (East China) Qingdao 266580 P. R. China Geosteering & Logging Research Institute Sinopec Matrix Corporation Qingdao 266071 P. R. China Research Center of Multiphase Flow in Porous Media School of Petroleum Engineering China University of Petroleum (East China) Qingdao 266580 P. R. China

During geological CO2storage, gravity segregation due to fluid density differences significantly affects the efficiency and safety of the process. This can result in premature CO2breakthrough, reduced storage efficiency, and increased leakage risks. This study aims to investigate how gas migrates in layered heterogeneous reservoirs over time due to prolonged density differences and to assess the resulting impact on fluid distribution. We use artificially layered heterogeneous sandstone cores for experimentation. After completing gas injection and water flooding experiments, the core was positioned with the low permeability layer (LPL) at the top and the high permeability layer (HPL) at the bottom for an extended period. Because the effects of density differences are not easily discernible during gas–water two-phase flow under typical driving forces, we applied micro-CT imaging technology to visualize and analyze how density differences influence gas flow within the core. The results demonstrate that during the static placement period following displacement, gas clusters exhibit different flow behaviors at the pore throats. Most gas clusters struggle to overcome the Jamin effect and enter into the upper pores; a few large-volume gas clusters, driven by density differences, partially pass through the throats into the upper pores, while the remaining portions are stranded within the throats, leading to a snap-off phenomenon; while some gas clusters successfully overcome the Jamin effect and enter the upper pores in significant numbers. The experimental findings indicate that the LPL effectively hinder the upward migration of the nonwetting phase gases from bottom and fluid density differences significantly influence gas–water distribution changes. This study provides critical insights for optimizing CO2storage and offers a new perspective on fluid behavior in layered heterogeneous reservoirs.

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Numerical Study on the Impact Characteristics of a Single Molten Lead Bismuth Droplet on Water

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SSRN 2024年

作者： Lin, Yue Zhang, Dalin Chen, Yutong Zhang, Xisi Deng, Jian Du, Peng Tian, Wenxi Qiu, Suizheng Su, Guanghui Department of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University No.28 Xianningxilu Beilinqu Shaanxi Xi’an710049 China Institute of Reactor Engineering Technology China Institute of Atomic Energy Beijing102413 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu610213 China

As an important link in the possible occurrence of steam explosions, the interaction between molten materials and coolant is of great significance for safety analysis in severe accidents of nuclear reactors. This study is based on the two-dimensional multiphase and multi-component fluid dynamics code ACENA to model the process of single molten lead bismuth droplet impacting a water tank and obtain the velocity changes of the molten droplet as it moves through the water tank. Furthermore, a sensitivity analysis of relevant factors such as the heat transfer area fraction and drag coefficient of the droplet is carried out. To verify models in ACENA, the computation results are compared to experimental data. It is demonstrated that the overall trend of the velocity curve acquired by the ACENA code during the interaction between a molten lead bismuth droplet and water is consistent with the experimental results. The droplet falling velocity increases with the increase in droplet temperature when the temperature of water is the same, and the droplet falling velocity increases with the increase of water temperature at the same droplet temperature. The simulation results by ACENA code for MFCI are in good agreement with experiments which verifies the accuracy of relevant models in ACENA. It can provide an effective means for safety analysis of nuclear reactors in China. © 2024, The Authors. All rights reserved.

关键词： Drops

Hydrogen Production from Chemical Looping Steam Reforming of Biomass Waste Cooking Oil

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SSRN 2022年

作者： Zeng, Pingchao Dou, Binlin Zhang, Hua Wang, Yadong Wu, Kai Zhao, Longfei Chen, Haisheng Xu, Yujie School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China

For highly efficient transformation and utilization of waste cooking oil, a new method for hydrogen production by indirect and auto-thermal chemical looping steam reforming (CLSR) of waste cooking oil (WCO) was developed in this work. In conventional and direct CLSR using WCO at a temperature of 650 °C, gas production, hydrogen selectivity, and fuel conversion were low due to the insufficient amount of reducing Ni and heating. Thus, the reactor temperature was increased to 750 °C to pyrolyze enough reducing gas to reduce OCs. Although 84% WCO conversion and 88% hydrogen selectivity were obtained, the OCs deactivated at the last 15 minutes due to the high-temperature sintering of the reduced Ni particles. On this basis, a new type of indirect CLSR with high-temperature steam-assisted pyrolysis of WCO in a two-stages fixed-bed reactor with high stability was developed, which fitted WCO feeding and avoided OCs sintering. The experimental results show that about 90% WCO conversion and about 89% hydrogen selectivity were obtained in indirect CLSR, and the highest hydrogen yield and selectivity were obtained under the conditions of upper pyrolysis temperature of 800 ℃ with a lower CLSR temperature of 600 ℃ and S/C=4.12. In addition, the effect of in-situ CO 2 capture on indirect CLSR achieves the feasibility of hydrogen production and minus carbon emissions. The multiple cycles experiments of indirect CLSR obtained about 90% hydrogen selectivity and fuel conversion, close to 0 CH 4 selectivity, and 24%~26% steam conversion. © 2022, The Authors. All rights reserved.

关键词： Hydrogen production

Study on the effect of particle flow state on the stability of LIBS carbon content detection signal 7

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Study on the effect of particle flow state on the stability ...

7th International Conference on power engineering, ICOPE 2019

作者： Pan, Yuqing Hu, Zhengtao Xu, Heng Zhou, Qulan Li, Na Deguchi, Yoshihiro State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Graduate School of Engineering Science Osaka University Japan

Rice husk, a type of biomass fuel, is rich in amorphous silica. Laser-induced breakdown spectroscopy (LIBS) is a fast-responding non-contact detection method which can realize on-line detection of rice ash components. This paper aims to explore the optimum working conditions of LIBS and extend the compatibility of LIBS technology. The paper uses the sample motion state simulation system to simulate ash, so that the particles can be laser-induced breakdown during the vertical drop and horizontal motion, and then the effect of particle flow state on the stability of the LIBS detection signal can be determined. In addition, the paper compares the effects of two laser pulse widths on the stability of LIBS detection signal by using a 1 ns pulse width laser and a 6 ns pulse width laser to improve the detection error. Experimental studies have found that long pulse width laser provides better stability of spectrum, and the relative standard deviation (RSD) of the detection result is smaller than that of short pulse width laser, and the RSD is smaller in the state of horizontally transferring samples, which can obtain the spectral signal with stronger line intensity. Moreover, sample in conveyor, by contrast, leads to more stable signals. © ICOPE 2019 - 7th International Conference on power engineering, Proceedings. All rights reserved.

关键词： Stability

Improvement and experimental study of scroll expander for organic rankine cycle

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Energy engineering: Journal of the Association of Energy engineering 2020年第4期117卷 225-235页

作者： Li, Lei Tao, Leren Gou, Yanan Zhang, Shan Zaozhuang University Zaozhuang277160 China University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China

The scroll expander used in organic Rankine cycle (ORC) system is improved, and its performance is analyzed experimentally. The modified profile and inlet hole of the scroll expander are enhanced, and the performance of the scroll expander before and after the improvement is analyzed. The results show that when the inlet pressure exceeds 0.7 MPa, the waist-shaped hole with a larger area is preferable. The scroll expander with a waist-shaped hole has a larger output power and wider optimal pressure range, and when the inlet pressure is 1.6 MPa, the maximum output power increases by 230 W. The output power and isentropic efficiency of the scroll expander can be improved by modifying the profile. When the inlet pressure is 1.6 MPa and the rotational speed is 1750 r/min, the maximum output power of the scroll expander is 1235 W, which is 120 W higher than that before the improvement. © 2020, Tech Science Press. All rights reserved.

关键词： Rankine cycle

Experimental Study on flow Patterns in Narrow Rectangular Channels

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SSRN 2022年

作者： Lv, Xindi Zhang, Dalin Song, Gongle Su, Guanghui Tian, Wenxi 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 Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China

Plate fuel elements are commonly used in compact nuclear reactors due to the advantages of high fuel consumption. In this paper, the two-phase flow pattern in the coolant channel of plate fuel elements, i.e. the rectangular narrow channel was studied. Visualization flow pattern experiments of upward steam-water two-phase flow in narrow rectangular channels, 745mm long and 67mm wide with gap widths of 1.3mm and 1.9mm, were investigated. The experiments were performed in the conditions of pressure ranging from 1 to 2MPa, mass flow rate ranging from 200 to 1500kg/(m2 ⋅s), inlet subcooling ranging from 20~100°C and tilt angle ranging from 0~ 45°. Three flow patterns, consisting of bubble flow, churn flow and annular flow, were obtained in a wide range of thermal parameters. flow patterns maps were plotted and the influences of pressure, mass flow rate, inlet subcooling, channel gap and tilt angle on the flow pattern transformation of narrow rectangular channel were studied. This study is of great significance for investigating the subsequent heat transfer process of two-phase flow in compact nuclear reactors. © 2022, The Authors. All rights reserved.

关键词： Two phase flow

Atomic Nickel on Graphitic Carbon Nitride as a Visible Light-Driven Hydrogen Production Photocatalyst Studied by X-ray Spectromicroscopy

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ACS Sustainable Chemistry and engineering 2023年第14期11卷 5390-5399页

作者： Huang, Yu-Cheng Li, Yanrui Arul, K. Thanigai Ohigashi, Takuji Nga, Ta Thi Thuy Lu, Ying-Rui Chen, Chi-Liang Chen, Jeng-Lung Shen, Shaohua Pong, Way-Faung Dong, Chung-Li Chou, Wu-Ching Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu30010 Taiwan Research Center for X-ray Science & Department of Physics Tamkang University New Taipei City25137 Taiwan International Research Center for Renewable Energy State Key laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Photon Factory Institute of Materials Structure Science High Energy Accelerator Research Organization Tsukabu305-0801 Japan UVSOR Synchrotron Facility Institute for Molecular Science Okazaki444-8585 Japan National Synchrotron Radiation Research Center Hsinchu30010 Taiwan

The photocatalytic production of solar hydrogen through water splitting by graphitic carbon nitride (g-C3N4) has gained substantial interest due to its advantageous characteristics, such as eco-friendliness, wealth on the earth, favorable bandgap, and easy preparation. Nevertheless, the performance for photocatalytic overall water splitting has been significantly restricted owing to the rapid recombination of charge carriers and slow catalytic kinetics. This investigation demonstrates the utilization of a single-atom Ni-terminating agent to coordinate with the heptazine moieties of g-C3N4, resulting in the formation of a new electronic orbital. g-C3N4 with single-atom Ni-termination can achieve highly efficient photocatalytic overall water splitting into H2 and H2O2 upon visible light irradiation, without requiring the use of any additional cocatalysts. The underlying cause of the enhanced photocatalytic performance of single-atom Ni-incorporated g-C3N4 in hydrogen evolution reaction is identified using synchrotron X-ray spectroscopy and microscopy. The X-ray spectro-microscopic results discover that the new hybrid orbital that is critical for optimizing photocatalysis is associated with carbon defects. The atomic and electronic structures and the band gap of g-C3N4 are adjusted by the new hybrid orbital. Moreover, it synergistically enhances visible light absorption, thereby promoting the separation and transfer of photogenerated charge carriers. The single-atom Ni and the adjacent C atom are recognized as the active sites for water oxidation and reduction, respectively, supporting the efficient photocatalytic splitting of water via a two-electron transfer pathway. This study demonstrated a promising material design for promoting photocatalytic activity in solar energy conversion applications. © 2023 American Chemical Society

关键词： Electronic structure