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Chem Catalysis 2025年第5期5卷

作者： Xue, Fei Zhang, Chunyang Liu, Maochang Liu, Feng Yan, Xueli Liu, Shangheng Peng, Huiping Hu, Zhiwei Pao, Chih-Wen Huang, Wei-Hsiang Yang, Ye Huang, Xiaoqing Xu, Yong i-lab of Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) Chinese Academy of Sciences (CAS) Suzhou 215123 China State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China International Research Center for Renewable Energy & State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China Max Planck Institute for Chemical Physics of Solids Nothnitzer Strasse 40 Dresden 01187 Germany National Synchrotron Radiation Research Center 101 Hsin-Ann Road Hsinchu 30076 Taiwan Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM) Xiamen 361005 China

CO2 photoconversion into value-added C2 products with high selectivity and efficiency is formidably challenging due to highly energetic and kinetic restriction of C–C coupling. Designing catalysts to overcome those b... 详细信息

CO₂ photoconversion into value-added C₂ products with high selectivity and efficiency is formidably challenging due to highly energetic and kinetic restriction of C–C coupling. Designing catalysts to overcome those barriers is therefore crucial. Here, for the first time, we demonstrate an amorphization strategy to boost photocatalytic CO₂ ethanolization. By integrating amorphous Pd onto Cd_0.9Zn_0.1S nanorods (a-Pd/CZS), an activity of 412.1 μmol g⁻¹ h⁻¹ and a selectivity of 96.5% for CO₂-to-C₂H₅OH photoconversion were achieved without a sacrificial agent with an apparent quantum efficiency (AQE) of 0.87% at 420 nm. The superior performance results from rapid migration of photogenerated electrons to amorphous Pd via interfacial Ohmic junction. In situ characterization and theoretical calculation further reveal that amorphous Pd can optimize CO₂ adsorption/activation and reduce the C–C coupling energy barrier via intensified interaction and stabilization with a ^∗OCCO intermediate, thereby maximizing conversion efficiency and selectivity. This work highlights an efficient photocatalyst for a CO₂-to-C₂ product and inspires high-performance photocatalyst design. © 2025 Elsevier Inc.

关键词： amorphization C2H5OH CO2 photocatalytic conversion SDG7: Affordable and clean energy

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A Least-Squares Solution to Nonlinear Steady-State Multi-Dimensional IHCP

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Journal of Thermal Science 1996年第1期5卷 39-41页

作者： Bai Bofeng Guo Liejin Chen Xuejun (State key Lab of multiphase flow in power engineering,Xi’an Jiao Tong University,Xi’an 710049,China) State Key Lab of Multiphase Flow in Power Engineering Xi’an Jiao Tong University Xi’an China

In this paper,the least-squares method is used to solve the Inverse Heat Conduction Problem(IHCP)to determine the space-wise variation of the unknown boundary condition on the inner surface of a helically coiled tube with fluid flow inside,electrical heating and insulation *** sensitivity coefficient is analyzed to give a rational distribution of the thermocouples. The results demonstrate that the method effectively extracts information about the unknown boundary condition for the heat conduction problem from the experimental measurements. The results also show that the least-squares method converges very quickly.

关键词： helically coiled tube least-squares method IHCP.

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Thermal-diffusive instabilities of laminar premixed CH4/H2/air flat flames 10

Thermal-diffusive instabilities of laminar premixed CH4/H2/a...

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10th Asia-Pacific Conference on Combustion, ASPACC 2015

作者： Jin, Wu Wang, Jinhua Yu, Senbin Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

As one of the most promising clean alternative fuels, natural gas has been widely used in automobile engines. However, due to the slow burning velocity of natural gas and its poor lean-burn ability, hydrogen is often added to improve its combustion behavior. Researches on the fundamental laminar premixed flame characteristics of CH4/H2 blends are of great significance to understand the combustion process in practical combustors. The intrinsic instability of laminar flame is one of the classic issues in flame dynamics, which presents the dynamic response of laminar premixed flamelets to weak perturbations. By studying dynamic mechanism of intrinsic instability, we can estimate the burning velocity more accurately and gain a deeper insight into the turbulent combustion process in spark ignition engines. In this study, the cellular instabilities of laminar premixed CH4/H2/air flat flames were studied using McKenna burner with OH-PLIF technique. It was found that the addition of H2 can broaden the lean combustion limit on flat flame burner with which the cellular instabilities were brought. The digital and OH-PLIF images were obtained to calculate the quantitative parameters of cellular length scale, which is associated with the properties of fuel mixtures such as Lewis number, Markstein number et al. Through the theoretic analysis, we make a thorough investigation on the mechanism about how the cellular scales were determined.

关键词： Natural gas

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An experimental study of premixed laminar methane/oxygen/argon flames doped with hydrogen at low pressure with synchrotron photoionization

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Chinese Science Bulletin 2008年第8期53卷 1262-1269页

作者： WANG JinHua HU ErJiana HUANG ZuoHua MA ZhiHao TIAN ZhenYu WANG Jina LI YuYana State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230029 China

Laminar premixed stoichiometric methane/hydrogen/oxygen/argon flames were investigated with tun- able synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spec- trometry techniques. The methane/hydrogen fuel blends with hydrogen volumetric fraction of 0, 20%, 40%, 60% and 80% were studied. All observed flame species, including stable intermediates and radi- cals in the flames, were detected by measuring photoionization mass spectra and photoionization effi- ciency (PIE) spectra. Mole fraction profiles of major species and intermediates were derived by scan- ning burner at some selected photon energies near ionization thresholds. The influence of hydrogen addition on mole fraction of major species and intermediates was analyzed. The results show that the major species mole fraction of CO, CO2 and CH4 decreases with the increase of hydrogen fraction. The mole fraction of intermediates measured in this experiment decreases remarkably with the increase of hydrogen fraction. This would be due to the increase of H and OH radicals by hydrogen addition and the high diffusivity and activity of H radical promoting the chemical reaction. In addition, the increase of H/C ratio with the increase of hydrogen fraction also leads to the decrease of the mole fraction of car- bon-related intermediates and contributes to the decrease of unburned and incomplete combustion products.

关键词：甲烷氢混合火焰同步加速器 MBMS

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Numerical study on convective heat transfer of supercritical CO_(2) in vertically upward and downward tubes

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Science China(Technological Sciences) 2021年第5期64卷 995-1006页

作者： YAN ChenShuai XU JinLiang ZHU BingGuo HE XiaoTian LIU GuangLin Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization North China Electric Power UniversityBeijing 102206China Key Laboratory of Power Station Energy Transfer Conversion and System Ministry of EducationNorth China Electric Power UniversityBeijing 102206China

The experimental measurement of supercritical pressure carbon dioxide(sCO_(2))heat transfer in vertical downward flow was performed in a circular tube with inner diameter of 10 ***,a three-dimensional numerical investigation of sCO_(2)heat transfer in upward and downward flows was performed in a vertical heated circular *** influence of heat flux,mass flux,and operating pressure on heat transfer under different flow directions were *** to the"pseudo-phase transition"viewpoint to supercritical fluids,the analogy to the subcritical inverted-annular film boiling model,the physical model to sCO_(2)heat transfer was established,where fluid region at the cross-section of circular tube was divided into gas-like region covering heated wall and core liquid-like phase ***,the thermal resistance mechanism which comprehensively reflected the effect of multiple factors including the thickness of the gas-like film or liquid-like region,fluid properties and turbulence on heat diffusion was ***,thermal resistance variation in upward flow is well identical with that of wall temperature and heat transfer deterioration is predicted *** addition,compared with thermal resistance in the core liquid-like region,gas-like film formation is determined to be the primary factor affecting heat transfer *** also show that total thermal resistance in upward flow is always larger than that in downward *** investigation can provide valuable guide to design and optimize sCO_(2)heaters.

关键词： supercritical CO_(2) flow direction pseudo-film heat transfer thermal resistance

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Performance and emission characteristics of a hydrogen-enriched compressed-natural-gas direct-injection spark ignition engine diluted with exhaust gas recirculation

Performance and emission characteristics of a hydrogen-enric...

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作者： Liu, Y.-F. Liu, B. Zeng, K. Huang, Z. Zhou, L. Sun, L. State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Compressed natural gas (CNG) has been widely used in city buses or taxis because of its relatively low price and great abundance. Most of the CNG engines externally mix the natural gas with the intake air and utilize a lean-burn strategy to achieve low nitrogen oxide (NOx) emissions and high fuel economy. However, the well-examined external mixing of gas fuel with the intake air will result in a volumetric efficiency loss at high engine loads and may cause backfire when the natural gas is enriched with hydrogen. Also, the lean-burn technique may not sufficiently satisfy increasingly restricted future legislation. In this paper, the use of the stoichiometric equivalence ratio with exhaust gas recirculation (EGR) was investigated experimentally on a direct-injection spark ignition engine fuelled with hydrogen-natural-gas blends. Attention is focused on the advantages of combining EGR with hydrogen enrichment. The results show that hydrogen enrichment increases the brake mean effective pressure, which dramatically deteriorates under high-level EGR. Optimal efficiencies are achieved with an EGR rate of 5-10 per cent;the NO x emissions can be decreased by about 80per cent with 25 per cent EGR dilution, but the combustion variation increases simultaneously. With hydrogen enrichment, the combustion variation can be controlled under 5per cent, while the NOx, hydrocarbon, and carbon monoxide emissions are kept at a low level. Worse EGR tolerance was exhibited for the late-injection-timing case. © Author 2011.

关键词： Efficiency

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Numerical analysis of the static performance of an annular aerostatic gas thrust bearing applied in the cryogenic turbo-expander of the EAST subsystem

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Plasma Science and Technology 2017年第2期19卷 115-122页

作者： Tianwei LAI Bao FU Shuangtao CHEN Qiyong ZHANG Yu HOU State Key Laboratory of Multiphase Flow in Power Engineering Xi＇an Jiaotong University Xi＇an 710049 People＇s Republic of China Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 People＇s Republic of China

The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust beating. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.

关键词： EAST helium cryogenic system aerostatic thrust beating inclination bearing load

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Study on ash fusion behaviors and physico-chemical characteristics of semi-coke and its blended fuel with coal 35

Study on ash fusion behaviors and physico-chemical character...

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35th Annual International Pittsburgh Coal Conference, PCC 2018

作者： Yuan, Maobo Wang, Chang'an Wang, Pengqian Tao, Zichen Du, Yongbo Zhao, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China

ISBN: (纸本)1890977357

With the rapid development of coal chemical industry in China, a large number of low-volatile carbon-based fuels such as semi-coke are in urgent need of combustion and utilization, and the co-combustion with high-volatile coal shows the potential to realize the large-scale utilization of semi-coke in coal-fired power plant. Because the blending coal can hardly match the design coal, it is easy to aggravate the degree of deposition and slagging on the heating surface and affect the operation of the boiler. However, the melting behavior of ash produced by blended coal with semi-coke combustion needs further study. In this paper, the ash melting behavior and physico-chemical characteristics of semi-coke and its blended fuel with coal were experimentally studied. Firstly, the relation of ash composition and ash melting behavior was observed by comparing the ash composition and ash fusion point of semi-coke and raw coal. Secondly, the influence of blending ratio and blending mode on the ash melting behavior of semi-coke blended fuel was studied by micro-computer ash melting point meter. Finally, the microstructure and physico-chemical properties of the melted ash at the softening temperature were evaluated by scanning electron microscope (SEM) technique with X-ray spectrometer (EDS) and X-ray diffractometer (XRD) technique. The experimental results showed that the mineral composition and oxide content in the semi-coke were different from the raw coal, which led to the change of coal ash fusibility. Meanwhile, the ash fusion point of semi-coke blended fuel could not be expressed linearly by the ash fusion point of its raw coal, and the influence of blending mode including in-furnace blending and out-furnace blending on the ash fusion point could be neglected. While the microstructure and physico-chemical properties were affected by the blending mode. Compared to the in-furnace blending, the carbon content was lower in out-furnace blending. Furthermore, the blending mode h

关键词： Coal

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Microfluidic-Encapsulated Phase Change Fibers with Graphene Coating for Passive Thermal Management

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Small 2025年 e2500839页

作者： Hao, Guanqiu Lyu, Le Gao, Wei Chang, Yaran Liu, Xiangdong Chen, Yongping Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application School of Environmental Science and Engineering Suzhou University of Science and Technology Suzhou 215009 China Department of Chemical and Biomolecular Engineering National University of Singapore Singapore 117585 Singapore College of Electrical Energy and Power Engineering Yangzhou University Yangzhou 225127 China School of Energy and Environment Southeast University Nanjing 210096 China Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials School of Materials Science and Engineering Peking University Beijing 100124 China

This paper introduces a novel method for encapsulating phase change materials (PCM) into non-toxic, flexible fibers using microfluidic techniques, enhances with graphene coating to passive thermal management. The phase change fibers feature a uniform core–shell structure with a lightweight porous yet dense shell that prevents PCM leakage. The dimensions of the fibers and the ratio of PCM to the shell material can be precisely controlled as required. A graphene coating is applied to the surface of the phase change fiber to enhance its thermal conductivity and emissivity, thereby improving passive cooling performance without compromising the fiber's structural integrity or sealing stability. In particular, thermal management experiments on the electronic components undergoing intermittent operation under periodic thermal load demonstrate that the thermal management by the graphene-coated phase change fiber (GPCF) can effectively reduce both peak and average temperatures of electronic devices. Remarkably, the pure passive cooling without any power consumption based on the GPCF amounts to the performance of the forced air cooling with an airspeed of 0.8 m s⁻¹, delivering substantial energy savings. The GPCF shows a great potential in thermal management of electronic devices subjected to periodic, short-term high loads, potentially offering significant savings in cooling-related energy consumption. © 2025 Wiley-VCH GmbH.

关键词： graphene coating microfluidic encapsulation passive thermal management phase change fibers

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Experimental Investigation on Ejector Performance Using R134a as Refrigerant

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Journal of Thermal Science 2019年第4期28卷 727-735页

作者： DAI Zhengshu YU Bo LIU Pengpeng CHEN Guangming ZHANG Hua School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of Air-conditioning Equipment and System Energy Conservation Zhuhai 519070China Institute of Refrigeration and Cryogenics Zhejiang UniversityHangzhou 310027China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093China

Ejector refrigeration has the advantage of low capital cost,simple design,reliable operation,long lifespan and almost no *** only weakness is the low efficiency and its intolerance to deviations from design operation condition.R134 a used in ejector refrigeration system gives better performance in comparison with many other environmental friendly refrigerants as the generation temperature is from 75℃to 80℃.The present work experimentally investigated the on-design and off-design performance of the ejector with fixed geometry using R134 a as refrigerant,and cycle performance of the ejector refrigeration *** experimental prototype was constructed and the effects of primary flow inlet pressure,secondary flow inlet pressure and ejector back pressure on ejector performance and cycle performance were investigated *** operation conditions are:primary flow inlet pressure from 2.2 MPa to 3.25 MPa,secondary flow inlet pressure from 0.36 MPa to 0.51 MPa,ejector back pressure from 0.45 MPa to 0.67 *** were drawn from the experimental results,and the experimental data can be used for validation of theoretical model for both critical and subcritical mode.

关键词： ejector performance refrigeration R134a experiment

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