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Design and performance investigation of modified dual reflector parabolic trough collector with double planar mirrors

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Science China(Technological Sciences) 2024年第3期67卷 902-918页

作者： LI Peijing LIU TaiXiu QIN YuanLong LI JiChao LIU QiBin School of Energy Powerand Mechanical EngineeringNorth China Electric Power University Beijing 226China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China department of thermal Science and Energy Engineering University of Science and Technology of ChinaHefei 230027China

In a typical parabolic trough collector(PTC), sunlight is concentrated at the bottom of the absorber tube. This concentrated solar flux leads to uneven heat distribution, resulting in high local temperatures and significant thermal stress on the absorber *** limitations have restricted the application of PTCs in solar thermochemistry and other fields and have impacted their safe operation. In this study, a new PTC with dual planar mirrors(DPMS) is proposed to homogenize the circumferential solar flux distribution of the absorber tube. A design method and single-objective optimization of the new PTC with a DPMS are proposed,and an uncertainty analysis of the operational and structural parameters is performed. A coupled light-heat-structure numerical model was developed to study the heat transfer performance and structural mechanical properties. The thermodynamic properties of the PTC with DPMS under different boundary conditions were analyzed. The results show that the circumferential temperature difference of the new PTC is within 2.6 K, and the circumferential thermal deformation is within 0.9 mm under typical working conditions(the inlet velocity of the heat transfer fluid is 3 m/s, inlet temperature is 573.15 K, and the direct normal irradiance is 1000 W/m^(2)). Compared with conventional PTCs, the circumferential temperature difference is reduced by 74%–90%, and the maximum thermal deformation along the y-axis is reduced by more than 95% under all working conditions(1–5 m/s, 373.5–675.15 K, 200–1000 W/m^(2)). The new PTC maintains the uniformity of the circumferential solar flux distribution for different operating parameters(sun incident angle of 0°–3°) and installation errors(±3 mm), is suitable for solar energy applications in various fields, and has the potential for large-scale applications.

关键词： solar thermal energy parabolic trough collector secondary reflector solar flux distribution optical optimization

Synthesis and characterization of a 1,3-dibutylimidazolium azide([BBIm][N_(3)]) : A promising green energetic ionic liquid

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Defence Technology（防务技术） 2024年第8期38卷 1-15页

作者： Nawel Matmat Amir Abdelaziz Djalal Trache Achour Sabrina Ahmed Fouzi Tarchoun Hani Boukeciat Sourbh Thakur Weiqiang Pang Thomas M.Klapotke Energetic Materials Laboratory(EMLab) Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17 Bordj El-BahriAlgiers 16046Algeria department of Organic Chemistry Bioorganic Chemistry and BiotechnologySilesian University of TechnologyB.Krzywoustego 444-100 GliwicePoland Xi'an Modern Chemistry Research Institute Xi'an 710065China Energetic Materials Research Department of ChemistryLudwig-Maximilian UniversityMunich Butenandtstrasse 5-13(D)D-81377 MunichGermany

In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs),the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N_(3)]),as a novel member in this ionic liquids *** chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy,1D,and 2D-NMR *** thermal behavior assessment was conducted through DSC and TGA *** analysis revealed an endothermic glass transition at T_(g)=-61℃,followed by an exothermic degradation event at T_(onset)=311℃.Similarly,TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the ***,the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS,it-KAS,and VYA/CE isoconversional kinetic ***,the Arrhenius parameters(E_(a)=154 kJ·mol^(-1),Log(A/s^(-1))=11.8) and the most probable reaction model g(a) were *** observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified *** findings revealed that[BBIm][N_(3)]EIL can be a promising candidate for advanced energetic material application.

关键词： 1,3-dibutyl-imidazolium azide[BBIm][N_(3)] Energetic imidazolium-base ionic liquids 1D-/2D-NMR analyses Short-term thermal stability Isoconversional approaches

Performance Enhancement of Parabolic Trough Collector by Using Homogenizer and Spiral

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Journal of thermal Science 2024年第2期33卷 658-674页

作者： LI Peijing LIU Taixiu QIN Yuanlong ZHENG Zhimei ZHAO Kai LIU Qibin School of Energy Powerand Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Science Beijing100049China department of thermal Science and Energy Engineering University of Science and Technology of ChinaHefei230027China Research Institute of Science and Technology of China Three Gorges Group Corporation Beijing100038China

In conventional parabolic trough collectors(PTCs),sunlight is concentrated at the bottom of the absorber tube,resulting in a significant circumferential temperature gradient across the absorber tube,heat loss and thermal deformation,which affects the safety and thermal performance of *** this study,a new receiver with homogenizer and spiral(RHS) is proposed,achieving the optical and thermal synergy to ameliorate the thermal deformation of the absorber tube and enhance thermal efficiency.A plane structure homogenizer is designed to improve uniformity of the concentrated solar flux of absorber tube through second *** combination with the spiral,it improves the optical-thermal efficiency of the PTC by enhancing heat exchange between the fluid and the backlight side of the absorber *** performance of the collector is numerically studied by building a three-dimensional coupled light-thermal-structure *** results show that the thermal deformation of the RHS is reduced by more than 96% and the optical-thermal efficiency is improved by 1.2%-0.63% compared with conventional receivers(CRs) under the same inlet temperature *** proposed receiver is validated to be effective in reducing thermal deformation and improving optical-thermal efficiency.

关键词： parabolic trough collector homogenizer thermal deformation spiral

Cooling History of Mesozoic Magmatism and Implications for Large-Scale Gold Mineralization in the Jiaodong Peninsula, East China: Constraints from T-t Paths Determined by U-Pb Thermochronology of Zircon and Apatite

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Journal of Earth Science 2024年第3期35卷 878-889页

作者： Guangyan Zhou Mingchun Song Long Li Yan Luo DGraham Pearson Jianbo Zhou Zhengjiang Ding Xuefeng Yu Yingxin Song Jie Li Shiyong Li Faculty of Earth Sciences China University of GeosciencesWuhan 430074China department of Earth&Atmospheric Sciences University of AlbertaEdmontonAlberta T6G 2E3Canada Hebei Key Laboratory of Strategic Critical Mineral Resources Hebei GEO UniversityShijiazhuang 050031China Shandong Provincial No.6 Exploration Institute of Geology and Mineral Resources Weihai 264209China College of Earth Sciences Jilin UniversityChangchun 130061China Ministry of Natural Resources Key Laboratory of Gold Mineralization processes and Resources Utilization Key Laboratory of Metallogenic-Geologic Processes and Comprehensive Utilization of Minerals Resources in Shandong ProvinceShandong Institute of Geological SciencesJinan 250013China Shandong Nuclear Industry Geological Group 273 Yantai 264006China

The Mesozoic intrusions of the Jiaodong Peninsula,eastern China,host giant gold *** the genesis of these deposits requires the determination of the source of the parental auriferous fluid and the timing of gold mineralization,which are strongly influenced by the cooling/uplift histories of the hosting *** performed an integrated U-Pb geochronology study on both zircon and apatite from four major magmatic episodes of the Jiaodong *** zircon and apatite U-Pb ages are 156.9±1.2 and 137.2±2.4 Ma for the Linglong intrusion,129.9±1.0 and 125.0±3.8 Ma for the Qujia intrusion,119.5±0.7 and 117.2±1.8 Ma for the Liulinzhuang intrusion,118.6±1.0 and 111.6±1.6 Ma for the Nansu intrusion,*** coupled zircon and apatite data of these granitoids indicate a slow cooling rate(11.9°C/Ma)in the Late Jurassic,and rapid uplift and cooling(35.8-29.2°C/Ma)in the Early *** dramatically increased uplift and cooling period in the Early Cretaceous are contemporaneous with large-scale gold mineralization in the Jiaodong *** implies that thermal upwelling of asthenosphere and related tectonic extension played an important role in gold remobilization and precipitation.

关键词： magmatism geochronology zircon apatite gold deposits Jiaodong Peninsula

General theory for designing phonon transport in alloyed/doped materials

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Science China(Physics,Mechanics & Astronomy) 2024年

作者： Chenhan Liu Chao Wu Wei Liu Yunshan Zhao Gang Zhang Hongmin Yang Yunfei Chen Micro-and Nano-scale thermal Measurement and thermal Management Laboratory Key Laboratory of Numerical Simulation for Large Complex Systems Ministry of Education School of Energy and Mechanical Engineering Nanjing Normal University School of Electrical and Automation Engineering Nanjing Normal University Phonon Engineering Research Center of Jiangsu Province Center for Quantum Transport and Thermal Energy Science Institute of Physics Frontiers and Interdisciplinary Sciences School of Physics and Technology Nanjing Normal University Institute of High-Performance Computing Agency for Science Technology and ResearchSingapore Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments School of Mechanical Engineering Southeast University

Alloying/doping is a widely used technique for improving the electrical, mechanical, and optical properties of ***, this technology induces significant distortions in the lattice structure, mass distribution, and potential field, greatly enhancing phonon scattering. Here, we introduce the concept of alloying/doping path and employ crystal symmetry, lattice deformation, and electron distribution to characterize it. Based on this new concept, the phonon thermal transport behavior in alloyed/doped materials can be well designed, and along different alloying/doping paths, the difference in thermal conductivity can be up to 45 times. On one hand, strategic alloying/doping that combines high crystal symmetry, large lattice contraction, and the same electron distribution suppresses phonon-phonon scattering phase space, induces phonon stiffening, and bolsters electronic structure symmetry, respectively. These synergistic effects significantly improve thermal conductivity. On the other hand, random alloying/doping has a low symmetry, leading to the typical “U” shape of alloying/doping level-dependent thermal conductivity. Our theory is corroborated in three-dimensional（3D） Si, 2D MoS2, and quasi-1D TiS3, affirming its efficacy and broad applicability in controlling phonon transport.

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Surface Morphology and Thermo-Electrical Energy Analysis of Polyaniline (PANI) Incorporated Cotton Fabric

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Energy Engineering 2024年第1期121卷 1-12页

作者： Md.Shohan Parvez Md.Mustafizur Rahman Mahendran Samykano Mohammad Yeakub Ali Automotive Engineering Research Group Faculty of Mechanical and Automotive Engineering TechnologyUniversiti Malaysia Pahang Al-Sultan AbdullahPekanMalaysia department of Textile Engineering Khulna University of Engineering&Technology(KUET)KhulnaBangladesh Centre for Research in Advanced Fluid and processes(CARIFF) Universiti Malaysia Pahang Al-Sultan AbdullahLebuhraya Tun RazakGambangMalaysia Mechanical Engineering Programme Area Faculty of EngineeringUniversiti Teknologi BruneiBruneiDarussalam

With the exponential development in wearable electronics,a significant paradigm shift is observed from rigid electronics to flexible wearable ***(PANI)is considered as a dominant material in this sector,as it is endowed with the optical properties of both metal and ***,its widespread application got delineated because of its irregular rigid form,level of conductivity,and precise choice of *** PANI in textile materials can generate promising functionality for wearable *** research work employed a straightforward in-situ chemical oxidative polymerization to synthesize PANI on Cotton fabric surfaces with varying dopant(HCl)***-treatment using NaOH is implemented to improve the conductivity of the fabric surface by increasing the monomer *** research explores the morphological and structural analysis employing SEM,FTIR and *** surface resistivity was measured using a digital multimeter,and thermal stability is measured using *** successful polymerization,a homogenous coating layer is *** is revealed that the simple pre-treatment technique significantly reduces the surface resistivity of Cotton fabric to 1.27 kΩ/cm with increasing acid concentration and thermal *** electro-thermal energy can also reach up to 38.2°C within 50 s with a deployed voltage of 15 *** modified fabric is anticipated to be used in thermal regulation,supercapacitor,sensor,UV shielding,antimicrobial and other prospective functional applications.

关键词： Polyaniline cotton in-situ polymerization SEM TGA heating fabric

High-strength and thermally stable TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy fabricated via selective laser melting

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2221-2232页

作者： Jiang Yu Yaoxiang Geng Yongkang Chen Xiao Wang Zhijie Zhang Hao Tang Junhua Xu Hongbo Ju Dongpeng Wang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China National Engineering Research Center of Near-Net Shape Forming for Metallic Materials Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic MaterialsSouth China University of TechnologyGuangzhou 510640China CEMMPRE-Centre for Mechanical Engineering Materials and processes Department of Mechanical EngineeringUniversity of CoimbraRua Luís Reis SantosCoimbra 3030-788Portugal

To increase the processability and plasticity of the selective laser melting(SLM)fabricated Al-Mn-Mg-Er-Zr alloys,a novel TiB_(2)-modified Al-Mn-Mg-Er-Zr alloy with a mixture of Al-Mn-Mg-Er-Zr and nano-TiB_(2) powders was fabricated by *** pro-cessability,microstructure,and mechanical properties of the alloy were systematically investigated by density measurement,microstruc-ture characterization,and mechanical properties *** alloys fabricated at 250 W displayed higher relative densities due to a uni-formly smooth top surface and appropriate laser energy *** maximum relative density value of the alloy reached(99.7±0.1)%,demonstrating good *** alloy exhibited a duplex grain microstructure consisting of columnar regions primarily and equiaxed regions with TiB_(2),Al6Mn,and Al3Er phases distributed along the grain *** directly aging treatment at a high tem-perature of 400℃,the strength of the SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy increased due to the precipitation of the secondary Al6Mn *** maximum yield strength and ultimate tensile strength of the aging alloy were measured to be(374±1)and(512±13)MPa,*** SLM-fabricated TiB_(2)/Al-Mn-Mg-Er-Zr alloy demonstrates exceptional strength and thermal stability due to the synergistic effects of the inhibition of grain growth,the incorporation of TiB_(2) nanoparticles,and the precipitation of secondary Al6Mn nanoparticles.

关键词： selective laser melting aluminum alloy processability mechanical properties thermal stability

Design and Analysis of S-CO_2 Cycle and Radial Turbine for SOFC Vehicle Waste-Heat Recovery

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Journal of thermal Science 2019年第3期28卷 559-570页

作者： XIA Liu LI Xuesong SONG Jian REN Xiaodong GU Chunwei Key Laboratory for thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Clean Energy processes (CEP) Laboratory Department of Chemical Engineering Imperial College London

Solid oxide fuel cell(SOFC) vehicles are considered to have broad prospects for development, and the high operating temperature of SOFC results in great potential for waste-heat recovery. Many concepts for utilizing waste heat of SOFC have been suggested and studied, and most of them directly couple an SOFC to a gas turbine, which require the SOFC to operate at an elevated pressure and make the system less flexible and thus harder to operate. In recent years, with the development of turbine and heat exchanger technology, the supercritical carbon dioxide(S-CO_2) power cycle has raised widespread attractions for the waste recovery. This study explores the potential of S-CO_2 Brayton cycle to realize waste-heat recovery for an SOFC vehicle. The SOFC can operate at atmospheric pressure, and the hybrid system is easier to operate than the directly coupled systems. In this paper, a simple recuperated S-CO_2 Brayton cycle is proposed and the key component, radial inflow turbine is designed and focused. The flow state of the designed turbine is analyzed in detail based on computational fluid dynamics(CFD) numerical simulation. Five cases with different impeller tip clearances are numerically simulated to study its influence on the turbine performance. In addition, off-design performance analysis of the radial inflow turbine is conducted considering the temperature fluctuation of SOFC in practical applications.

关键词： SOFC waste-heat recovery supercritical carbon dioxide radial turbine

Computer Modeling and Validations of Steel Gear Heat Treatment processes Using Commercial Software DANTE

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Journal of Shanghai Jiaotong university(Science) 2011年第2期16卷 152-156页

作者：李志超 FERGUSON B.Lynn deformation Control Technology Inc.

The heat treatment process of a gear made of AISI 9310 carburized steel is modeled using the commercial heat treatment simulation software *** carburization and quenching processes affect the residual stress distribution and distortion of heat-treated parts,which are important to service quality and fatigue ***/VCARB is used to design the boost/diffuse schedule of a vacuum carburization *** quenching is modeled following the vacuum carburization *** gradient and phase transformation are two main sources of distortion and residual stresses in quenched *** relation of the carbon distribution,thermal gradient,and phase transformations during quenching is studied through the gear modeling *** of geometry,the residual stress distribution after quenching is non-uniform along the gear *** general,the root fillet has higher residual compression than either the root or tooth face locations after traditional oil quenching of carburized *** predicted residual stresses from the oil quenching model are imported into a single tooth fatigue bending *** gear stresses under bending load indicate the possible cracking locations during the bending fatigue *** importance of heat treatment residual stresses during gear design is pointed out,and it is commonly ignored in the gear design and manufacturing industry.

关键词： vacuum carburization distortion residual stress phase transformation