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Constructing electron transport channel of SnO2/BaSO4 on g-C3N4 for enhanced visible-light-driven photocatalytic H2 production

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Materials Today Catalysis

Materials Today Catalysis 2025年 9卷

作者： Dong, Gongyue Guo, Xiaojuan Cheng, Cheng Chen, Feng Zhang, Jinfeng Du, Yanping Meng, Wei Liu, Maochang Shi, Jinwen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Guangdong Provincial Key Laboratory of Multi-energy Complementary Distributed Energy Systems Dongguan University of Technology Dongguan523808 China School of Engineering Lancaster University LancasterLA1 4YW United Kingdom Gansu Company PipeChina Lanzhou730060 China Hunan Provincial Key Lab of Dark Tea and Jin-Hua Department of Material & Chemical Engineering Hunan City University Yiyang413000 China

Graphitic carbon nitride (g-C3N4) is confronted with the issue of poor utilization of photogenerated charge carriers, thereby leading to limited performance of photocatalytic hydrogen (H2) production, which restricts its potential application. Herein, the electron transport material SnO2/BaSO4 was synthesized to integrate with g-C3N4 for addressing the above problem. Various characterizations were conducted to investigate the g-C3N4-SnO2/BaSO4 photocatalyst, and it demonstrated that photogenerated electrons from g-C3N4 expeditiously migrate to SnO2/BaSO4 nanoparticles, which markedly hindered photogenerated carriers’ recombination. Subsequently, the g-C3N4-SnO2/BaSO4 photocatalyst demonstrated promoted photocatalytic H2 production at a rate of 14.2 μmol h−1 under visible-light illumination, which was 2.5 times higher than that of pristine g-C3N4. © 2025 The Authors

关键词： Barium sulfate

Dye visualization of the wake of a near-wall particle in response to a periodic oscillation

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Measurement: Sensors 2021年 13卷

作者： Li, Xing Zhang, Haibin Bai, Bofeng State Key Laboratory of Multiphase Flow in Power Engineering School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'anShaanxi710049 China

In turbulent dispersed multiphase flows, the interaction between the particle wake and the ambient turbulent fluctuation can be crucial for the change of the multiphase system. This issue is extremely complex due to the chaotic nature of the turbulence. In this paper, the ambient turbulent fluctuation of certain frequency is simulated by the Karman vortex street behind a horizontally placed cylinder, and the response of the wake of a stationary near-wall particle to the oncoming oscillation is investigated. The dye visualization is used to mark the vortex structures of the wake and the oncoming oscillation, respectively, and power spectrum analysis is conducted to reveal the features in the frequency domain. Results show that at relatively low Rep, the oncoming oscillation has little effect on the wake. As Rep increases, the response of the wake to the oncoming oscillation is evident. High-frequency fluctuation dissipates very fast and only exists near the particle. On the contrary, the life span of the low-frequency fluctuation lasts for a much longer period and exists far downstream. In addition, the self-induced vortex shedding is not notable and is overwhelmed by the oncoming oscillation. © 2020 The Author(s)

关键词： Wakes

Experimental Study on Fragmentation Characteristics of Molten Stainless Steel Discharged into Liquid Lbe Pool

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SSRN 2024年

作者： Fan, Shuowang Chen, Yutong Zhang, Dalin Deng, Jian Zhang, Xisi Wu, Xiaoli Tian, Wenxi Qiu, Suizheng Su, Guanghui School of Nuclear Science and Technology Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi’an710049 China Shanghai Nuclear Engineering Research and Design Institute Co. Ltd 29 Hongcao Road Shanghai200233 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China China Institute of Atomic Energy Beijing611731 China

The LFR is a candidate for the Generation-IV nuclear systems, where the process of MFCI differs from that occurred in LWRs and SFRs. In the absence of experimental study and widely applied theoretical models for LFRs, experiments on the interaction between molten SS and liquid LBE are conducted in this study under eight conditions. The morphological characteristics and fragment sizes of the products are analyzed based on the hydrodynamic effect parameter (We) and thermal effect parameter (Tic). Simplified thermal fragmentation models are established, where the innermost layer of the solidified shell is subjected to the maximum tangential compressive stress, while the outermost layer is subjected to the maximum tangential tensile stress. As the shell thickness increases, the total tangential stress of the outermost layer decreases. The fragmentation will occur when the maximum tangential stress on the shell exceeds the shell tensile strength. © 2024, The Authors. All rights reserved.

关键词： Tensile strength

Experimental Study of Liquid Immersion Cooling for Different Cylindrical Lithium-Ion Batteries Under Rapid Charging Conditions

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SSRN 2022年

作者： Li, Yang Bai, Minli Zhou, Zhifu Lv, Jizu Hu, Chengzhi Gao, Linsong Peng, Chunyang Li, Yulong Li, Yubai Song, Yongchen Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education Dalian University of Technology Dalian116024 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

In this study, the fluorinated liquid immersion cooling scheme has been proposed and tested for cooling the six different types of cylindrical lithium-ion batteries (LIBs) under fast charging conditions. SF33, with the boiling point of 33.4 °C, is chosen as the fluorinated liquid for the immersion cooling. Firstly, the voltage and temperature responses of LIBs under fast charging conditions with natural convection and SF33 immersion cooling were explored. It is found that the SF33 immersion cooling has a significant advantage over natural convection on controlling the battery temperature, thus ensuring the stability and safety of LIBs in the fast charging process. Subsequently, the high-speed photography was used to observe the bubble behaviors in the cooling process of SF33, and the heat transfer mechanism in the two-phase heat transfer process corresponding to immersion cooling of LIB was preliminary analyzed and discussed. It can be concluded that when the charging current is higher, the phenomenon of subcooled boiling as well as saturation boiling is generated in the SF33. The transition from single-phase convective heat transfer to boiling heat transfer greatly increases the heat transfer coefficient. © 2022, The Authors. All rights reserved.

关键词： Liquids

A New Structure Tube for Supercritical Co 2 Turbulent flow with High Non-Uniform Heat Flux

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SSRN 2023年

作者： Wang, Yanjuan Gao, Shuo Shi, Weijie Liu, Qibin Xu, Jinliang The Beijing Key Laboratory of Multiphase Flow and Heat Transfer North China Electric Power University Beijing102206 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100190 China

Supercritical carbon dioxide (sCO2) has been a promising alternative working medium in coal-fired power plants, high-temperature solar power systems, and fuel cells. In these cases, sCO2 is in a round tube under high temperature and pressure with high non-uniform heat flux (NUH). In this study, a novel structure tube is proposed to match high NUH with thermal resistance by changing tube eccentricity. A three-dimensional (3D) multiphysical coupling model was constructed. The novel structure can reduce Tmax and T effectively for the half-cycle uniform heat flux (HUH) and NUH cases. The maximum thermal stress decreased by 23 and 29% and Tmax decreased by 29.6 K and 24.8 K for HUH and NUH cases when Ec increased from 0 to 0.4. A comparison was made between the proposed structure, thin-walled tube, and traditional tube. Results showed that the performance of the proposed tube is the best. Tmax decreases by approximately 55 K compared with the traditional and thin-walled tubes. σeq,max of the eccentric tube is the smallest. Furthermore, the structure will facilitate the safety and economics of the tube. Consequently, a novel insight is presented for the design and optimization of sCO2 tube under high NUH. © 2023, The Authors. All rights reserved.

关键词： Heat transfer

POD analysis on vortical structures in MVG wake by Liutex core line identification

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Journal of Hydrodynamics 2020年第3期32卷 497-509页

作者： Xiang-rui Dong Xiao-shu Cai Yinlin Dong Chaoqun Liu 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 Department of Mathematics University of Central ArkansasConway 72035USA Department of Mathematics University of Texas at ArlingtonArlington 76019USA

The Liutex core line method, first combined with the snapshot proper orthogonal decomposition (POD), is utilized in a supersonic micro-vortex generator (MVG) wake flow at Ma = 2.5 and Reθ = 5 760 to reveal the physical significance of each POD mode of the flow field. Compared with other scalar-based vortex identification methods, the Liutex core line identification is verified to be the most appropriate approach that is threshold-free and provides full information of a fluid rotation motion. Meanwhile, the Liutex integration is employed to quantitatively track the evolution of the vortices in MVG wake and is applied to the determination of the effective control section of the MVG wake for the optimization study of MVG design. The physical mechanism of each POD mode for multi-scale and multi-frequency vortical structures is investigated by using Liutex core line identification to give some revelations. For the mean mode (mode 0) indicating the time-averaged velocity flowfield of the MVG wake flow, a pair of primary counter-rotating streamwise vortices and another pair of secondary vortices is uniquely identified by two pairs of Liutex core lines with Liutex magnitude. In contrast, mode 1 is featured by a fluctuated roll-up motion of streamwise vortex, and the streamwise component of the MVG wake is demonstrated to be dominant in terms of the total kinetic energy contribution. Meanwhile, a dominant shedding frequency of St = 0.072 is detected from the temporal behavior of mode 2, which has the organized arc-shaped vortex structures shedding from MVG induced by the K-H instability. Additionally, mode 4 subjects to low-frequency oscillations of the wall vortices and thus takes a relatively lower frequency of St = 0.044.

关键词： Proper orthogonal decomposition(POD) vortex identification Liutex vortex core lines micro-vortex generator(MVG)

Pattern and Dynamics of Methane/Water Two-Phase flow in Deep-Shale Illite Nanoslits

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SSRN 2024年

作者： Wang, Rui Yang, Xu Li, Gao Zheng, Wenxiu Zou, Zhenhai Sun, Chengzhen State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China State Key Laboratory of Oil and Gas Reservoir Geology and Exploration Southwest Petroleum University Sichuan Chengdu610500 China Air and Missile Defense College Air Force Engineering University Shaanxi Xi’an710051 China Wuhan Second Ship Design and Research Institute Wuhan430202 China

Developing deep shale gas is crucial for the sustainable development of unconventional energy sources. Deep shale has a high illite content, and understanding the structure and flow behaviors of methane and water coexisting in deep shale illite nanoslits is essential for methane transport and production in deep shale reservoirs. Here, molecular dynamics simulations were performed to investigate the methane and water flow characteristics in slit-shaped illite nanopores. The effects of water saturation, acceleration, and pore size on two-phase flow are elucidated. The results show that water molecules preferentially adsorb on the surface of the illite channel. As the water saturation increases, the water phase gradually forms a water film, water bridge, and water lock, ultimately creating methane nanobubbles surrounded by the water phase. The existence of the water phase compresses the methane flow space. With increasing water saturation, the peak methane density near the channel wall gradually disappears, and the density distribution curves show parabolic shapes. The methane flow flux decreases with the increase of water saturation, mainly when the water saturation increases from 0% to 40%. In illite slits with pore sizes ranging from 2 to 4 nm, the flow rates of water and methane increase with increased pore size. These results are expected to provide insights into developing deep shale gas reservoirs, such as optimizing hydraulic fracturing design and reliably predicting production performance. © 2024, The Authors. All rights reserved.

关键词： Methane

Investigations on affinity law under gas–liquid conditions in multistage radial and mixed-flow multiphase pumps

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International Journal of Fluid Engineering

International Journal of Fluid engineering 2024年第1期1卷 56-70页

作者： Liang Chang Chenyu Yang Xiaobin Su Xiaoyu Dai Qiang Xu Liejin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Affinity laws have been widely used in pump design and simulation under high-temperature and corrosive *** applying such laws,it is possible to shorten development cycles and reduce test ***,current applications of affinity laws are still limited to liquid *** this paper,expressions for affinity laws and their applicability are investigated for multistage radial and mixed-flow multiphase pumps under gas–liquid conditions.A high-pressure(30 MPa)gas–liquid experimental platform is constructed,and three-stage and 25-stage radial pumps and a 15-stage mixed-flow pump are investigated,with specific speeds of 107 and *** gas compressibility taken into account,the gas–liquid two-phase flow rate,head,and power,and the corresponding dimensionless hydraulic coefficients,are defined for multiphase *** deterioration of gas–liquid pressurization performance is found to be divided into three processes with different dynamic mechanisms,corresponding to three flow *** inlet gas volume fraction of pump is used to judge dynamic *** the same inlet gas volume fractionsλ_(1)=λ_(2),when the gas–liquid flows in two pumps have the same flow pattern,dynamic similarity will be *** affinity law that is established shows good applicability to the three-stage radial multiphase pump,with goodness of fit R^(2)larger than 0.9 for the two-phaseΨ_(m)–Φ_(m)andΠ_(m)–Φ_(m)performance ***,experimental results indicate that the affinity law also has good applicability to multiphase pumps with different stage numbers and blade structures under gas–liquid conditions.

关键词： flow law radial

Low-energy and accelerated hydrogen release from MgH2–5 wt% NaTiOxH catalyzed hydrogen storage reactor by graphite responsive microwave

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Journal of Magnesium and Alloys 2025年

作者： Wang, Bofei Wu, Zhen Liu, Honghao Yang, Fusheng Zhang, Zaoxiao Yao, Jing Li, Qian Cao, Hujun Li, Bo State Key Laboratory of Fluorine & Nitrogen Chemicals School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'an710049 China State Key Laboratory of Multiphase Flow for Power Engineering Xi'an Jiaotong University Xi'an710049 China National Engineering Research Center for Magnesium Alloys Chongqing University Chongqing400044 China Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian116023 China Faculty of Engineering Electrical Energy Management Group University of Bristol BristolBS8 1QU United Kingdom

Owing to high thermal stability and large reaction enthalpy, MgH2 has high reaction temperatures and sluggish reaction kinetics in the dehydrogenation process, which consumes lots of energy. To achieve hydrogen release with low energy consumption, accelerated reaction rate, and high heating uniformity, this paper proposes a novel method of graphite responsive microwave-assisted thermal management with NaTiOxH catalyst. A multi-physics model of the 5 wt% NaTiOxH catalyzed MgH2 reactor integrated with a microwave generator is developed to investigate the reaction, heat and mass transfer process of hydrogen release. It is found that the graphite responsive microwave heating method could improve the temperature uniformity of reaction bed, reduce the energy consumption by at least 10.71% and save the hydrogen release time by 53.49% compared with the traditional electric heating method. Moreover, the hydrogen desorption thermodynamics could be improved with the increase of microwave power. The hydrogen release time is shortened by 19.55% with the increase of 20 W microwave power. Meanwhile, it is also concluded that the microwave excitation frequency of 2.1 GHz and the graphite content of 2 wt% have better heating performance. Therefore, it can be verified that the graphite responsive microwave heating helps to low-energy and accelerated hydrogen release from MgH2 hydrogen storage reactor. © 2025

关键词： Reaction rates