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Effect of Thermal Radiation Heat Transfer on the Temperature Measurement by the Thermocouple in Premixed Laminar Flames

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Journal of Thermal Science 2022年第2期31卷 541-551页

作者： JIN Kairu tian zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In the past 30 years,the effect of thermal radiation and convection heat transfer,which are predominant at high temperature and can affect the measurement accuracy of thermocouple,were not fully considered in the field of laminar flame researches.In this work,the effect of thermal radiation heat transfer was newly calculated by determining the spectral irradiation heat flux from the whole space to thermocouple and the radiation heat loss from thermocouple junction to surroundings.Analysis reveals that the thermocouple itself maintains at high temperature,resulting serious thermal radiation heat loss,which can be compensated via receiving energy from convection-transferred heat as well as thermal radiation emitted by flame and burner surface.Such method was applied to correct the temperatures measured by thermocouple in rich nitromethane flame as reference.The results indicate that the radiation heat loss plays a dominant role,while the radiations emitted by flame and burner surface account for minor contribution with the percentage of 20.78%at the height above burner(HAB)of 0.4 mm,3.63%at HAB of 2.0 mm and even smaller at higher HAB.Temperature correction states that the maximum temperature error is 117.60 K,where the effect of thermal radiation emitted by flame and burner surface is less than 1.75 K.Consequently,it is provably reasonable and feasible to concentrate on the radiation heat loss and ignore the effect of thermal radiation emitted by flame and burner in real combustion processes.

关键词： thermal radiation heat transfer temperature error premixed laminar flame

Investigation of the Laminar Premixed n-Propylamine Flame

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Journal of Thermal Science 2022年第3期31卷 854-866页

作者： LI Wang CHEN Jintao YANG Jiuzhong tian zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China National Synchrotron Radiation Laboratory University of Science and TechnologyHefei230029China

The laminar premixed n-propylamine(NPA)flame with equivalence ratio of 1.70 has been investigated at 4666.28 Pa using tunable synchrotron photoionization and molecular-beam mass spectrometry techniques.Chemical structures and mole fractions of 40 species were determined.Ethenol,allylamine,butadiyne,vinylacetylene,1,3-butadiene,1-butene,2-butene,n-butyl radical,1,3-cyclopentadiene,cyclopentene,2-pentene,benzene,toluene,ethylbenzene,2-propen-1-imine,cyclopropanimine,pyrrole,2-butenenitrile and n-butylamine were newly identified in the amine flames.Mole fraction profiles of some species including reactants,intermediates and products in the NPA flame were *** and N_(2)were observed as the primary N-containing products in the NPA flame,which was different from the result that NO was the major N-containing products in previous studies of nitrogen flames.The bond energies of NPA were calculated through quantum chemistry calculations on the basis of density functional theory at the CBS-QB3 level.It showed that the CH_(3)CH_(2)-CH_(2)NH_(2)bond was the weakest and NPA mainly decomposed to CH_(2)NH_(2)and C_(2)H_(5)radicals.The H-abstractions at C_(α)by OH/O(NPA+OH=CH_(3)CH_(2)CHNH_(2)+H_(2)O and NPA+O=CH_(3)CH_(2)CHNH_(2)+OH)had significant promoting effects on NPA consumption.The N conversion chain of NPA under flame conditions was proposed and detailed analysis with respect to intermediates especially the nitrogen-containing species were provided.The results will enrich the understanding of NPA flame and are essential to further establish the kinetic mechanism.

关键词： n-propylamine low-pressure laminar premixed flame intermediates mole fraction quantum chemistry calculation molecular beam mass spectrometry

Fe-Promoted Copper Oxide Thin-Film Catalysts for the Catalytic Reduction of N_(2)O in the Presence of Methane

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Journal of Thermal Science 2023年第2期32卷 531-541页

作者： MUHAMMAD Waqas WU Lingnan EI KASMI Achraf MUHAMMAD Ammar tian zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Mechanical Engineering College of Engineering and TechnologyUniversity of SargodhaSargodha 40100Pakistan Laboratory LSIA UAE/U02ENSAHNational School of Applied Sciences of Al HoceimaAbdelmalek Essaadi UniversityAl Hoceima 32003Morocco Department of Chemical Engineering Technology Government College UniversityFaisalabad 38000Pakistan

Thin-film catalysts are recently recognized as promising catalysts due to their reduced amount of materials and good catalytic activity,leading to low-cost and high-efficiency catalysts.A series of CuFeO_(x)thin-film catalysts were prepared with different Fe contents using a one-step method as well as tested for the catalytic reduction of nitrous oxide(N_(2)O)in the presence of CH_(4)at a high GH SV of 185000 mL/(g·h).The increase of iron strongly affects the dispersion and leads to the creation of a less-active segregated Fe_(2)O_(3)phase,which was confirmed by XRD,EDX,and XPS outcomes.The results show that the synergistic properties between Cu and Fe,which affect the CuFeOxfilm catalysts in many aspects,such as the hollow-like texture,specific surface area,nano-crystallite size,the surface contents of Cu^(+),Fe^(3+),and oxygen species,the reductive strength and the strong active sites on the surface.Using DFT calculations,the adsorption and decomposition energy profiles of N_(2)O on the CuFeO_(2)(012)surface model were explored.The surface Fe-site and hollow-site are active for N_(2)O decomposition,and the decomposition energy barriers on the Fe-site and the hollow-site are 1.02 eV and 1.25 eV respectively at 0 K.The strategy adopted here to tailor the activity through low-doping Fe-oxide catalysts could establish a promising way to improve the catalytic reduction of N_(2)O with CH_(4).

关键词： catalytic reduction thin-film catalysts doping strategy density functional theory calculations N_(2)O decomposition

Experimental and Modeling Study on C_(2)H_(2)Oxidation and Aromatics Formation at 1.2 MPa

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Journal of Thermal Science 2023年第2期32卷 866-880页

作者： tian zhenyu tian Dongxu JiN Kairu CHNE Jintao JIN Zhihao LI Wang DU Lijun YANG Jiuzhong Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

Oxidation of acetylene(C_(2)H_(2))has been investigated in a high-pressure jet-stirred reactor(HP-JSR)with equivalence ratiosΦ=0.5,1.0,2.0 and 3.0 in the temperature range of 650 K-900 K at 1.2 MPa.18 products and intermediates were analyzed qualitatively and quantitatively by gas chromatography(GC)and gas chromatography-mass spectrometry(GC-MS).Generally,withΦincreasing,the production of intermediates increases significantly.CH_(4),C_(2)H_(4),C_(2)H_(6),C_(3)H_(6)and C_(3)H_(8)were important intermediates,which were formed abundantly atΦ=3.0.Sufficient light hydrocarbon intermediates could be an important reason for significant formation of cyclopentadiene,benzene,toluene and styrene atΦ=3.0.A detailed kinetic mechanism consisting of 299 species and 2041 reactions has been developed with reasonable predictions against the present data and previous results obtained at 0.1 MPa.According to flux and sensitivity analysis,H and OH radicals play important roles in the consumption of C_(2)H_(2).The combinations among light hydrocarbons and their free radicals are the main generation pathways of aromatics.C_(3)H_(3),IC_(4)H_(5)and AC_(3)H_(5)are important precursors for the formation of aromatics.By comparing the results of atmospheric pressure and high pressure,it can be found that increasing the pressure is conducive to fuel consumption and aromatics generation.

关键词： acetylene high pressure oxidation jet-stirred reactor aromatics mechanism flux analysis sensitivity analysis

Cu-Promoted Cobalt Oxide Film Catalyst for Efficient Gas Emissions Abatement

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Journal of Thermal Science 2019年第2期28卷 225-231页

作者： EL KASMI Achraf WAQAS Muhammad MOUNTAPMBEME KOUTOU Patrick tian zhenyu Institute of Engineering Thermophysics Chinese Academy of Sciences University of Chinese Academy of Sciences National Advanced School Engineering of Maroua University of Maroua

Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, we report the slight loading of Cu in cobalt spinel using a one-step pulsed-spray evaporation chemical vapor deposition(PSE-CVD) synthesis technique for efficient short-chain volatile organic compounds(VOCs) emissions treatment. Crystalline structure and morphology analyses revealed nano-crystallite sizes and open-like morphology. The catalytic performance was evaluated through the complete oxidation of C_3H_6, as a short-chain representative model of VOCs, at a high gas hourly space velocity(GHSV). Very good activity was obtained towards the complete abatement of C_3H_6 at low temperature and no carbon monoxide(CO) was formed during the oxidation process. Slightly-promoted Co_3O_4 catalyst with Cu introduction resulted in high catalytic activity comparing to the performance of the catalysts in the literature, due to the high dispersion of Cu and high active surface oxygen amount. Moreover, to evaluate the capability of the used catalysts under near realistic reaction conditions, CO_2 effect on the catalytic activity was performed and the catalyst exhibited very good results. Thus, the adopted slightly-doping strategy to tailor a high active catalyst at low temperature could establish a very promising route to strongly enhance the activity of such other catalysts towards gas emissions abatement at low temperature.

关键词： low Cu-doping PSE-CVD technique thin film catalysts complete catalytic oxidation VOCs

清仪阁中千金帖——嘉树堂藏宋拓《定武兰亭》研究

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湖北美术学院学报 2024年第1期 32-37页

作者：田振宇嘉兴南湖学院

《定武兰亭》系王羲之《兰亭序》传世诸多版本中的一个大类,翻刻版本数量极多。清嘉道间金石家张廷济收藏过一本定武兰亭的宋拓本,是明代顾从义玉泓馆旧物,经考证发现,还曾被晚清龚自珍之子龚橙收藏。通过校对勘验,这本五字已损的定武... 详细信息

《定武兰亭》系王羲之《兰亭序》传世诸多版本中的一个大类,翻刻版本数量极多。清嘉道间金石家张廷济收藏过一本定武兰亭的宋拓本,是明代顾从义玉泓馆旧物,经考证发现,还曾被晚清龚自珍之子龚橙收藏。通过校对勘验,这本五字已损的定武兰亭拓本应为宋拓宋刻,原石出自上海明代望族潘允端家,曾经受到翁方纲等清代学者关注,此本是目前所知同石拓本中年代最早,保存最完好的一本。

关键词：兰亭序版本张廷济宋拓碑帖

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国内VOCs来源、排放标准及脱除技术分析

工程热物理学报 2024年第6期45卷 1825-1837页

作者：于丹田振玉杜利军邝九杰陈劲涛苏冠宇中国科学院工程热物理研究所北京100190 中国科学院大学北京100049 华北电力大学能源动力与机械工程学院北京102206 中国科学院工程热物理研究所煤转化国家重点实验室北京100190

作为一种典型的大气污染物,VOCs对大气环境及人体健康危害极大。VOCs的高效清洁脱除是我国生态环境保护的重大需求,也是国家十四五规划的重要内容。本文基于我国经济发展的现状,总结了国内VOCs的来源特征,国家、地方及行业的排放标准,... 详细信息

作为一种典型的大气污染物,VOCs对大气环境及人体健康危害极大。VOCs的高效清洁脱除是我国生态环境保护的重大需求,也是国家十四五规划的重要内容。本文基于我国经济发展的现状,总结了国内VOCs的来源特征,国家、地方及行业的排放标准,分析了回收法和销毁法两大类VOCs脱除技术的发展现状,提出了多方法结合的技术特征,并预测了未来VOCs脱除技术的优势发展方向。

关键词： VOCs 来源排放标准脱除技术催化氧化

Study of low-pressure premixed laminar n-heptane+propane/oxygen/nitrogen flames

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Chinese Science Bulletin 2009年第9期54卷 1477-1486页

作者： YU Wu WEI LiXia MA ZhiHao HUANG ZuoHua YUAN Tao tian zhenyu LI YuYang 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

Low-pressure premixed laminar n-heptane+propane/oxygen/nitrogen flames were investigated with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam sampling mass spectrometry. Three flames with different mass percentage of propane in the fuel blends of 0%, 10%, and 20% were studied. The combustion intermediates were identified by comparing the measured IEs with those values in literatures. Mole fraction profiles of the main species were compared among the three flames. The experimental results provide detailed data in understanding the combustion of n-heptane and n-heptane/propane blends in engine. They are also helpful in establishing and verifying the kinetic models.

关键词：正庚烷火焰丙烷混层低压氮氧真空紫外

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