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Chinese Chemical Letters 2024年第4期35卷 160-165页

作者： Wengao Zeng Yuchen Dong Xiaoyuan Ye Ziying Zhang Tuo Zhang Xiangjiu Guan liejin guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

Achieving a high carrier migration efficiency by constructing built-in electric field is one of the promising approaches for promoting photocatalytic activity. Herein, we have designed a donor-acceptor(D-A) crystalline carbon nitride(APMCN) with 4-amino-2,6-dihydroxypyrimidine(AP) as electron donor, in which the pyrimidine ring was well embedded in the heptazine ring via hydrogen-bonding effect during hydrothermal process. The APMCN shows superior charge-transfer due to giant built-in electric field(5.94times higher than pristine carbon nitride), thereby exhibiting excellent photocatalytic H_(2) evolution rate(1350 μmol/h) with a high AQY(62.8%) at 400 nm. Mechanistic analysis based on detailed experimental investigation together with theoretical analysis reveals that the excellent photocatalytic activity is attributed to the promoted charge separation by the giant internal electric field originated from the D–A structure.

关键词： Crystalline carbon nitride Built-in electric field Donor-acceptor structure Photocatalysis Hydrogen production

Cascade utilization of full spectrum solar energy for achieving simultaneous hydrogen production and all-day thermoelectric conversion

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Journal of Energy Chemistry 2024年第9期96卷 318-327页

作者： Tuo Zhang Liang Dong Baoyuan Wang Jingkuo Qu Xiaoyuan Ye Wengao Zeng Ze Gao Bin Zhu Ziying Zhang Xiangjiu Guan liejin guo International Research Center for Renewable Energy(IRCRE) State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina

Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen ***,the practical application is hindered by the relatively low conversion efficiency resulting from the inadequate utilization of solar spectrum with significant waste in the form of ***,current equipment struggles to maintain all-day operation subjected to the lack of light during ***,a novel hybrid system integrating photothermal catalytic(PTC)reactor,thermoelectric generator(TEG),and phase change materials(PCM)was proposed and designed(named as PTC-TEG-PCM)to address these challenges and enable simultaneous overall seawater splitting and 24-hour power *** PTC system effectively maintains in an optimal temperature range to maximize photothermal-assisted photocatalytic hydrogen *** TEG component recycles the low-grade waste heat for power generation,complementing the shortcoming of photocatalytic conversion and achieving cascade utilization of full-spectrum solar ***,exceptional thermal storage capability of PCM allow for the conversion of released heat into electricity during nighttime,contributing significantly to the overall power output and enabling PTC-TEG-PCM to operate for more than 12 h under the actual *** to traditional PTC system,the overall energy conversion efficiency of the PTC-TEG-PCM system can be increased by∼500%,while maintaining the solar-to-hydrogen *** advancement of this novel system demonstrated that recycling waste heat from the PTC system and utilizing heat absorption/release capability of PCM for thermoelectric application are effective strategies to improve solar energy *** flexible parameter designing,PTC-TEG-PCM can be applied in various scenarios,offering high efficiency,stability,and sustainability.

关键词： Hybrid solar energy conversion system Photocatalytic overall seawatersplitting Thermoelectric power generation Phase change materials All-day operation

An active learning workflow for predicting hydrogen atom adsorption energies on binary oxides based on local electronic transfer features

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Green Energy & Environment 2024年第10期 1489-1496页

作者： Wenhao Jing Zihao Jiao Mengmeng Song Ya Liu liejin guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Department of Energy and Power Engineering Shandong University of Technology

Machine learning combined with density functional theory（DFT） enables rapid exploration of catalyst descriptors space such as adsorption energy, facilitating rapid and effective catalyst screening. However, there is still a lack of models for predicting adsorption energies on oxides,due to the complexity of elemental species and the ambiguous coordination environment. This work proposes an active learning workflow（Le NN） founded on local electronic transfer features（e） and the principle of coordinate rotation invariance. By accurately characterizing the electron transfer to adsorption site atoms and their surrounding geometric structures, Le NN mitigates abrupt feature changes due to different element types and clarifies coordination environments. As a result, it enables the prediction of *H adsorption energy on binary oxide surfaces with a mean absolute error（MAE） below 0.18 e V. Moreover, we incorporate local coverage（θl） and leverage neutral network ensemble to establish an active learning workflow, attaining a prediction MAE below 0.2 e V for 5419 multi-*H adsorption structures. These findings validate the universality and capability of the proposed features in predicting *H adsorption energy on binary oxide surfaces.

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入口效应对管内压力及含气率分布的影响研究

工程热物理学报 2024年第5期45卷 1405-1410页

作者：于海洋徐强曹业奇黄博郭烈锦西安交通大学动力工程多相流国家重点实验室西安710049

本文在直径80mm,高度11m的竖直管内对空气-水两相流动开展了可视化实验研究。实验的工况选取为表观气相速度J_(G)=0.03~16.53m·s^(-1),液相速度J_(G)=0.04~2.00m·s^(-1)。根据压力、压差传感器获取的数据,本文分析了入口效应对两相流... 详细信息

本文在直径80mm,高度11m的竖直管内对空气-水两相流动开展了可视化实验研究。实验的工况选取为表观气相速度J_(G)=0.03~16.53m·s^(-1),液相速度J_(G)=0.04~2.00m·s^(-1)。根据压力、压差传感器获取的数据,本文分析了入口效应对两相流动的影响。在泡状流动区域内,压力随气速的增加而下降的趋势较缓,在弹状流内下降趋势加快。在流动转变为搅动流时,压力下降趋势再次减缓。随着液速增加,各位置的压力下降由缓到急的趋势所对应的气速逐渐增大。在气速大于10m·s^(-1)时,发生了靠近入口位置的含气率突然增大的现象。随着液速增加,入口处含气率突增现象对应的气速逐渐降低。

关键词：入口效应含气率压力分布

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离心泵内气液两相流动的数值模拟与实验研究

工程热物理学报 2024年第8期45卷 2396-2402页

作者：苏筱斌徐强杨晨宇戴晓宇郭烈锦西安交通大学动力工程多相流国家重点实验室西安710049

分叶式叶轮由于其叶片的分离和偏移能够很好地处理气液流动而被广泛应用在石油工业中。本文采用叶轮可视化及数值模拟相结合的方法研究了分叶式叶轮内的气液流动特性。在该叶轮中,气团会率先出现在内叶片入口及外叶片的吸力面。气团在... 详细信息

分叶式叶轮由于其叶片的分离和偏移能够很好地处理气液流动而被广泛应用在石油工业中。本文采用叶轮可视化及数值模拟相结合的方法研究了分叶式叶轮内的气液流动特性。在该叶轮中,气团会率先出现在内叶片入口及外叶片的吸力面。气团在延伸至叶片分离和偏移的位置时,受到来自相邻流道流体的冲击。采用欧拉–欧拉模型时,数值模拟得到的叶轮内气液流动与可视化得到的结果基本一致。在叶轮流道中,被气团占据的区域失去了增压能力,而气团未占据的区域仍保留一定的增压性能。

关键词：离心泵叶轮可视化数值模拟气液流动

A review on thermal application of metal foam

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Science China(Technological Sciences) 2020年第12期63卷 2469-2490页

作者： CHEN Kang guo liejin WANG Hui State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Institute of Solar Engineering Technology Northwest Engineering Corporation LimitedPowerChinaXi’an 710065China School of Environmental Science and Engineering Donghua UniversityShanghai 201620China

Heat exchangers embedded with metal foam are drawing increasing attention in the thermal application field,due to the performance of low density,large ratio of surface area to volume as well as high thermal conductivity. In these applications,compact heat exchanger,solar thermal facilities and thermal energy storage are the three core components. This paper focuses on the lasted advances in thermal applications,presenting a review of theoretical and experimental progress over metal foam in thermal application. The empirical and theoretical models for pressure drop,heat transfer coefficient and performance evaluation criteria of compact heat exchangers with metal foam are reviewed and discussed,especially different optimized *** is a trade-off between heat transfer enhancement and increase of pressure drop. Some exploratory work performed by present authors are also introduced. The manufacturing,heat transfer and flow characteristics of tube bundle wrapped with metal foam are taken into account for optimization of heat exchanger. It is confirmed that the conversion mechanism of heat transfer is carried out that heat conduction is the dominative term at high dimension permeability. The correlations of heat transfer rate and pressure drop for staggered and single row tube bundle wrapped with metal foam are concluded,respectively. The effects of different bonding methods are revealed for point-contact in metal foam and base tube. The powder-sintering method can provide a stable and minimum-thickness bonding layer. Various types of solar thermal facilities utilized metal foam to improve the energy conversion efficiency from solar radiant energy to thermal energy are also reviewed and discussed,including solar collector for intermediate-low temperature utilization and solar receiver for high temperature utilization. The Last but not least,existing and future metal foam thermal application stations are overviewed.

关键词： metal foam heat transfer enhancement solar thermal facilities thermal energy storage

Theoretical and experimental advances on heat transfer and flow characteristics of metal foams

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Science China(Technological Sciences) 2020年第5期63卷 705-718页

作者： WANG Hui guo liejin CHEN Kang School of Environmental Science and Engineering Donghua UniversityShanghai 201620China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China Institute of Solar Engineering Technology Northwest Engineering Corporation LimitedPowerChinaXi’an 710065China

Open cell metal foam can be applied to greatly improve thermal performance of heat sink and heat exchanger,so that it has been widely used in the fields of thermal(or heat)control system of aerospace vehicle and energy utilization system and become a very important topic for research in the aerospace thermophysics field,and more and more attentions have been *** optimal design of metal foam heat transfer devices is based on the understanding the flow and heat transfer characteristics in metal *** article reviews some recent progresses of theoretical and experimental researches on heat transfer enhancement and flow characteristics of metal *** found that the pore cell simplification models of metal foams generally fall into four categories,among which the most commonly used cell model is Kelivin *** exploratory works performed by the current authors are also introduced,such as the effect of boundary conditions on the heat transfer enhancement;the theoretical modelling of interfacial convective heat transfer taking into account heat conduction between foam ligaments;and the flow characteristics under relatively high *** analytical results show that the flow characteristics of metal foam at relatively high speed are completely different from those at low speed,a further thorough study of the heat transfer and flow characteristics of metal foam is necessarily *** this paper,two types of partial filling techniques are *** heat transfer performance of partially filled tubes was evaluated by both the performance evaluation criteria and the performance evaluation plot of enhanced heat transfer techniques oriented for *** results show that the filling type of metal foam have a significant impact on its heat transfer enhancement ***,the filling method of metal foam should be further studied,in order to optimize the thermophysical properties of heat transfer devices.

关键词： metal foam effective thermal conductivity interfacial convective heat transfer coefficient heat transfer enhancement thermal radiation

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蒸汽射流直接接触凝结诱导振动特性研究

化工学报 2024年第8期75卷 2723-2733,F0001页

作者：洪奥越徐强蒋帅之李翔宇马小俊郭烈锦西安交通大学动力工程多相流国家重点实验室陕西西安710049

蒸汽射流在管内过冷水流中的直接接触凝结会诱导严重的管道振动。采用高速摄像机与加速度传感器,捕捉了蒸汽射流气羽演化及其诱导的管道振动。通过实验定量描述了考虑气羽形貌的气羽灰度质心振荡与管道振动特性。发现界面振荡流型下气... 详细信息

蒸汽射流在管内过冷水流中的直接接触凝结会诱导严重的管道振动。采用高速摄像机与加速度传感器,捕捉了蒸汽射流气羽演化及其诱导的管道振动。通过实验定量描述了考虑气羽形貌的气羽灰度质心振荡与管道振动特性。发现界面振荡流型下气羽灰度质心的振荡幅度最大,间歇振荡流型下次之,稳定凝结流型下最小。随着蒸汽质量流速升高,质心振荡及管道振动强度都向着趋于稳定的方向发展,表现出极强相关性。在此基础上绘制了管道振动强度随蒸汽质量流速及过冷水温度的分布图,振动强度随着过冷水温度的升高而升高。相关性分析表明气羽灰度质心的轴向振荡是沿蒸汽喷射方向的管道振动强度的主导因素。

关键词：蒸汽射流直接接触凝结灰度质心振动特性

Hierarchical growth of a novel Mn-Bi coupled BiVO4 arrays for enhanced photoelectrochemical water splitting

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Nano Research 2019年第3期12卷 575-580页

作者： Lu Wang Jinzhan Su liejin guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering School cf Energy & Power Engineering Xian Jiaotong University Xian 710049 China

Oxygen evolving catalyst (OEC) is a critical determinant for the efficiency of photoelectrochemical (PEC) water splitting. Here we report an approach to depositing a novel manganese borate (Mn-Bi) OER catalyst on BiVO4 nanocone photoanode by photodeposition in sodium borate buffer solution containing Mn(Ⅱ) ions. Due to the spontaneous photo-electric-field-enhancement effect at the vertically oriented BiVO4 nanocone structure, spherical Mn-Bi nanoparticle was selectively photodeposited at the apex of BiVO4 nanocone. Significant improvement of photocurrent was observed for the obtained hierarchical Mn-Bi/BiVO4 photoanode which could be ascribed to enhanced hole injection efficiency, especially in low bias region. It was observed that the injection efficiency of Mn-Bi/BiVO4 is 98% which gave a photocurrent of 0.94 mA/cm^2 at 1.5 V vs. RHE.

关键词： bismuth vanadate photoelectrochemistry solar water splitting oxygen evolution

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铂纳米团簇催化剂的制备及产氢性能研究

化学工程 2024年第5期52卷 19-24,32页

作者：李鲁冰张蕾卫莉婷苏进展郭烈锦西安交通大学动力工程多相流国家重点实验室陕西西安710049

电催化产氢技术对于推动清洁能源的发展至关重要。基于强金属-载体相互作用,利用铁单原子锚定效应制备负载于多孔碳氮材料的超细铂纳米团簇材料Pt@Fe-N-C,并对材料进行结构表征以及电催化测试。结果表明:Pt@Fe-N-C继承了ZIF-8的正十二... 详细信息

电催化产氢技术对于推动清洁能源的发展至关重要。基于强金属-载体相互作用,利用铁单原子锚定效应制备负载于多孔碳氮材料的超细铂纳米团簇材料Pt@Fe-N-C,并对材料进行结构表征以及电催化测试。结果表明:Pt@Fe-N-C继承了ZIF-8的正十二面体的多孔结构,且其中的铁单原子通过锚定铂纳米团簇实现铂的良好分散。该材料在0.5 mol/L硫酸溶液中展现出优异的HER(电催化析氢反应)活性和稳定性,过电势η_(10)仅为17 mV,且在3000圈循环退化测试后,η_(10)仅增加4 mV。此外,在20 mV(***/AgCl)过电势下,Pt@Fe-N-C的质量活性[12.43 mA/(cm^(2)·μg)]是商业铂碳[2.05 mA/(cm^(2)·μg)]的6.1倍。因此,利用单原子锚定效应分散铂是一种降低贵金属使用量的有效策略,并为今后发展低贵金属电催化材料提供新的思路。

关键词：催化剂强金属-载体相互作用纳米材料氢能可再生能源