资源类型

期刊论文 35

年份

2023 2

2022 5

2021 5

2020 2

2019 3

2014 1

2012 1

2011 1

2010 6

2009 2

2008 2

2007 4

2001 1

展开 ︾

关键词

阻燃 2

ABS 1

APP 1

BDP 1

SiO2 1

三相异步电机 1

低导热率 1

双燃料 1

反应可控压燃 1

可发性聚苯乙烯泡沫 1

喷射策略 1

天然气 1

废气再循环 1

抑烟性 1

气相燃烧法 1

火焰 1

1

生物基多孔涂层 1

电场控制 1

展开 ︾

检索范围:

排序: 展示方式:

Observation of premixed flame fronts by laser tomography

MU Kejin, WANG Yue, LEI Yu, ZHANG Zhedian, NIE Chaoqun, XIAO Yunhan

《能源前沿(英文)》 2008年 第2卷 第4期   页码 427-432 doi: 10.1007/s11708-008-0069-3

摘要: The principle of combustion field detection by using laser tomography, as well as exploitation of the laser tomography apparatus and the tool for image processing is described. An experiment detecting flame fronts by laser tomography was made by employing a V-shaped premixed flame. The results show that the instantaneous geometric shape of flame wrinkles within the light sheet can be clearly resolved. The contours of the flame fronts are precisely tracked through active contour models (ACM) from the digital images of laser tomography, laying the basis for the quantitative analysis of flame wrinkling and propagation.

关键词: combustion     tomography apparatus     processing     exploitation     propagation    

Experimental study on premixed combustion of spherically propagating methanol-air-nitrogen flames

Xiangang WANG, Zhiyuan ZHANG, Zuohua HUANG, Xibin WANG, Haiyan MIAO,

《能源前沿(英文)》 2010年 第4卷 第2期   页码 223-233 doi: 10.1007/s11708-010-0016-y

摘要: The outward propagation and development of surface instability of the spark-ignited spherical premixed flames for methanol-air-nitrogen mixtures were experimentally studied by using a constant volume combustion chamber and a high-speed schlieren photography system. The laminar burning velocities, the mass burning fluxes, and the Markstein lengths were obtained at different equivalence ratios, dilution ratios, initial temperatures, and pressures. The laminar burning velocities and the mass burning fluxes give a similar curve versus the equivalence ratios. They increase with the increase of initial temperature and decrease with the increase of dilution ratio. The laminar burning velocity decreases with elevating the initial pressure, while the mass burning flux increases with the increase of the initial pressure. Markstein length decreases slightly with the increase of initial temperature for the rich mixtures. High initial pressure corresponds to low Markstein length. Markstein length increases with the increase of dilution ratio, which is more obvious when the mixture becomes leaner. Equivalence ratio has a slight impact on the development of the diffusive-thermal cellular structure at elevated initial pressures. The initial pressure has a significant influence on the occurrence of the flame front cellular structure. At the elevated pressures, the cracks on the flame surface branch and develop into the cell structure. These cells are bounded by cracks emitting a bright light, which may indicate soot formation. For very lean mixture combustion, the buoyancy effect and cooling effect from the spark electrodes have a significant impact on the flame propagation. The hydrodynamic instability, inhibited with the increase of initial temperature around the stoichiometric equivalence ratio, is enhanced with the increase of initial pressure and suppressed by mixture dilution.

关键词: methanol     spherical flame     propagation characteristics     flame instabilities    

Identifying combustion intermediates in premixed MTBE/gasoline/oxygen flame probed via synchrotron radiation

YAO Chunde, LI Jing, LI Qi, JI Qing, HUANG Chaoqun, WEI Lixia, WANG Jing, TIAN Zhenyu, LI Yuyang, QI Fei

《能源前沿(英文)》 2007年 第1卷 第1期   页码 79-84 doi: 10.1007/s11708-007-0007-9

摘要: Molecular-beam sampling mass spectrometry (MBMS) combined with tunable synchrotron radiation photoionization technique offers obvious advantages for the study of flame chemistry over other techniques because of the precision measurement of the combustion intermediates and products in flame. In this paper, the results to identify combustion intermediates in low-pressure premixed gasoline/oxygen flame with the synchrotron radiation were reported. Based on the results obtained, the formation process of five products and the difference between gasoline/oxygen and MTBE/gasoline/oxygen flame were emphatically analyzed. The results achieved provide data basis for the analysis of intermediates and radicals in flame, and are helpful to establish the kinetic modeling of gasoline/oxygen and MTBE/gasoline/oxygen flames.

关键词: synchrotron     photoionization technique     chemistry     analysis     difference    

Soot size distribution in lightly sooting premixed flames of benzene and toluene

Wang LIU, Jiaqi ZHAI, Baiyang LIN, He LIN, Dong HAN

《能源前沿(英文)》 2020年 第14卷 第1期   页码 18-26 doi: 10.1007/s11708-020-0663-6

摘要: The evolution of particle size distribution function (PSDF) of soot in premixed flames of benzene and toluene was studied on a burner stabilized stagnation (BSS) flame platform. The cold gas velocities were changed to hold the maximum flame temperatures of different flames approximately constant. The PSDFs of all the test flames exhibited a bimodal distribution, i.e., a small-size nucleation mode and a large-size accumulation mode. It was observed that soot nucleation and particle growth in the benzene flame were stronger than those in the toluene flame at short residence times. At longer residence times, the PSDFs of the two flames were similar, and the toluene flame showed a larger particle size distribution range and a higher particle volume fraction than the benzene flame.

关键词: premixed flame     soot     particle size distribution function     benzene     toluene    

Exergy losses in premixed flames of dimethyl ether and hydrogen blends

Tongbin ZHAO, Jiabo ZHANG, Dehao JU, Zhen HUANG, Dong HAN

《能源前沿(英文)》 2019年 第13卷 第4期   页码 658-666 doi: 10.1007/s11708-019-0645-8

摘要: A second-law thermodynamic analysis was conducted for stoichiometric premixed dimethyl ether (DME)/hydrogen (H )/air flames at atmospheric pressure. The exergy losses from the irreversibility sources, i.e., chemical reaction, heat conduction and species diffusion, and those from partial combustion products were analyzed in the flames with changed fuel blends. It is observed that, regardless of the fuel blends, chemical reaction contributes most to the exergy losses, followed by incomplete combustion, and heat conduction, while mass diffusion has the least contribution to exergy loss. The results also indicate that increased H substitution decreases the exergy losses from reactions, conduction, and diffusion, primarily because of the flame thickness reduction at elevated H substitution. The decreases in exergy losses by chemical reactions and heat conduction are higher, but the exergy loss reduction by diffusion is slight. However, the exergy losses from incomplete combustion increase with H substitution, because the fractions of the unburned fuels and combustion intermediates, e.g., H and OH radical, increase. The overall exergy losses in the DME/H flames decrease by about 5% with increased H substitution from 0% to 100%.

关键词: second law analysis     flame     dimethyl ether (DME)     hydrogen     binary fuels    

Numerical simulation of laminar premixed combustion in a porous burner

ZHAO Pinghui, CHEN Yiliang, LIU Minghou, DING Min, ZHANG Genxuan

《能源前沿(英文)》 2007年 第1卷 第2期   页码 233-238 doi: 10.1007/s11708-007-0032-8

摘要: Premixed combustion in porous media differs substantially from combustion in free space. The interphase heat transfer between a gas mixture and a porous medium becomes dominant in the premixed combustion process. In this paper, the premixed combustion of CH

关键词: interphase     mixture     dominant     Premixed combustion     premixed combustion    

Transient process of methane-oxygen diffusion flame-street establishment in a microchannel

《能源前沿(英文)》 2022年 第16卷 第6期   页码 988-999 doi: 10.1007/s11708-021-0755-y

摘要: “Flame-street” is an interesting diffusion flame behavior in which a series of flame-segments is separately distributed along the mixing layer in a narrow channel. This experimental phenomenon was experimentally and numerically investigated with the focus on the steady-state, thermo-chemical flame structures in previous literature. In the present paper, the dynamic formation process of a methane-oxygen diffusion flame-street structure was simulated with a reacting flow solver developed based on the open-source framework OpenFOAM. By imposing a certain amount of ignition-energy near the channel outlet, a reaction-kernel was formed and bifurcated. Subsequently, three separate flames were consecutively generated from this kernel and propagated within the channel. The whole process was completed within 15 ms and all the discrete flames were eventually in a steady-state. Interestingly, different propagation features were observed for the three flame segments: The leading flame experienced a flame shape/type change from a tribrachial structure in its fast-propagating phase to a long, trailing diffusion tail after being anchored to the inlet. The successive flame had a much lower propagation speed, keeping its two wing-like (fuel-lean premixed and fuel-rich premixed) structure while moving toward its stabilization location, which was approximately in the middle of the channel. The last flame, after the ignition source was turned-off, was immediately convected a bit downstream, and eventually featured a similar two-branch-like structure as the second one. Moreover, chemical insights for the premixed and diffusion branches of the leading flame were also provided with the change of significance of some key elementary reactions focused on, in order to attain a detailed profiling of the flame-type transition. This paper is a first-ever one discussing the transient formation of flame-streets in literature and is believed to be useful for obtaining a comprehensive understanding of this unique flame characteristics from a dynamic point of view.

关键词: micro-combustion     flame-street     diffusion flame     mixing layer     flame propagation speed    

Modification of premixed combustion in shear layers by grid turbulence

MU Kejin, WANG Yue, ZHANG Zhedian, NIE Chaoqun

《能源前沿(英文)》 2007年 第1卷 第2期   页码 245-250 doi: 10.1007/s11708-007-0034-6

摘要: The influence of grid turbulence on the shear layer of a jet and the premixed flames embedded in it was investigated in the present study. The velocity field of the jet was measured by using hot-wire anemometry. It was found that grid turbulence reduced turbulence intensities in the shear layer and suppressed low frequency fluctuation. Moreover, the energy contained in small-scale fluctuation was increased and turbulence became homogeneous. The results indicate that grid turbulence inhibits the formation of a large-scale coherent structure in the shear layer. Flame temperature was measured by using a compensated fine-wire thermocouple. It was found that grid turbulence reduced low frequency fluctuation of the flame fronts, increased the small-scale wrinkles and elevated the mean temperature of the flame zone. The results show that grid turbulence can enhance and stabilize premixed flames in shear flow.

关键词: homogeneous     fine-wire thermocouple     temperature     hot-wire anemometry     premixed    

NC flame pipe cutting machine tool based on open architecture CNC system

Xiaogen NIE, Yanbing LIU

《机械工程前沿(英文)》 2009年 第4卷 第2期   页码 147-152 doi: 10.1007/s11465-009-0025-x

摘要: Based on the analysis of the principle and flame movement of a pipe cutting machine tool, a retrofit NC flame pipe cutting machine tool (NFPCM) that can meet the demands of cutting various pipes is proposed. The paper deals with the design and implementation of an open architecture CNC system for the NFPCM, many of whose aspects are similar to milling machines; however, different from their machining processes and control strategies. The paper emphasizes on the NC system structure and the method for directly creating the NC file according to the cutting type and parameters. Further, the paper develops the program and sets up the open and module NC system.

关键词: flame pipe cutting     flame incision tracks     CNC     open architecture CNC system    

Experimental study on the laminar flame speed of hydrogen/natural gas/air mixtures

Chen DONG, Qulan ZHOU, Xiaoguang ZHANG, Qinxin ZHAO, Tongmo XU, Shi’en HUI

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 417-422 doi: 10.1007/s11705-010-0515-8

摘要: Laminar flame speeds of hydrogen/natural gas/air mixtures have been measured over a full range of fuel compositions (0–100% volumetric fraction of H ) and a wide range of equivalence ratio using Bunsen burner. High sensitivity scientific CCD camera is use to capture the image of laminar flame. The reaction zone area is employed to calculate the laminar flame speed. The initial temperature and pressure of fuel air mixtures are 293 K and 1 atm. The laminar flame speeds of hydrogen/air mixture and natural gas/air mixture reach their maximum values 2.933 and 0.374 m/s when equivalence ratios equal to 1.7 and 1.1, respectively. The laminar flame speeds of hydrogen/natural gas/air mixtures rise with the increase of volumetric fraction of hydrogen. Moreover, the increase in laminar flame speed as the volumetric fraction of hydrogen increases presents an exponential increasing trend versus volumetric fraction of hydrogen. Empirical formulas to calculate the laminar flame speeds of hydrogen, natural gas, and hydrogen/natural gas mixtures are also given. Using these formulas, the laminar flame speed at different hydrogen fractions and equivalence ratios can be calculated.

关键词: laminar flame speed     experimental study     Bunsen flame    

Experimental study on velocity characteristics of recirculation zone in humid air non-premixed flame

GU Xin, ZANG Shusheng, GE Bing

《能源前沿(英文)》 2008年 第2卷 第2期   页码 140-144 doi: 10.1007/s11708-008-0037-y

摘要: To examine the effect of the flow field within the recirculation zone on flame structure, the characteristic velocity fields of methane/humid air flame in non-premixed combustion behind a disc bluff-body burner were experimentally studied by particle image velocimeter (PIV).The results show that two stagnation points exist on the centerline in the recirculation zone flame. However, the distance of the two stagnation points in humid air combustion shortens, and the minimal dimensionless velocity increases compared with the conventional non-humid air combustion. In addition, the positional curves of the minimal velocities can be partitioned into three phases representing three different flame patterns. The analysis of axial minimal velocities on the centerline and their positions under different co-flow air velocity conditions reveals that fuel-to-air velocity ratio is the crucial parameter that governs humid air combustion flame characteristics.

关键词: distance     bluff-body     fuel-to-air velocity     stagnation     parameter    

Experimental and kinetic study on laminar flame speeds of ammonia/syngas/air at a high temperature and

《能源前沿(英文)》 2022年 第16卷 第2期   页码 263-276 doi: 10.1007/s11708-021-0791-7

摘要: The laminar flame speeds of ammonia mixed with syngas at a high pressure, temperature, and different syngas ratios were measured. The data obtained were fitted at different pressures, temperatures, syngas ratios, and equivalence ratios. Four kinetic models (the Glarborg model, Shrestha model, Mei model, and Han model) were compared and validated with experimental data. Pathway, sensitivity and radical pool analysis are conducted to find out the deep kinetic insight on ammonia oxidation and NO formation. The pathway analysis shows that H abstraction reactions and NHi combination reactions play important roles in ammonia oxidation. NO formation is closely related to H, OH, the O radical produced, and formation reactions. NO is mainly formed from reaction, HNO+ H= NO+ H2. Furthermore, both ammonia oxidation and NO formation are sensitive to small radical reactions and ammonia related reactions.

关键词: ammonia mixed with syngas     laminar flame speed     kinetic model     sensitivity analysis     pathway analysis    

Molybdenum disulfide@nickel phyllosilicate hybrid for improving the flame retardancy and wear resistance

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2114-2126 doi: 10.1007/s11705-023-2357-1

摘要: In this study, nickel phyllosilicate was synthesized based on molybdenum disulfide (MoS2@NiPS) by the sol-gel method, and then MoS2@NiPS was used to prepare epoxy composites. The thermal stability, flame retardancy, and frictional performances of epoxy composites were studied. With the addition of 3 wt% MoS2@NiPS, the epoxy composite increased the limiting oxygen index from 23.8% to 26.1% and reduced the vertical burning time from 166 s for epoxy resin to 35 s. The residual char of the epoxy composite increased from 11.8 to 20.2 wt%. MoS2@NiPS promoted the graphitization of the residual char, and facilitated the formation of a dense and continuous char layer, thereby improving the fire safety of epoxy resin. The epoxy composite with 3 wt% MoS2@NiPS had excellent wear resistance property with a wear rate of 2.19 × 10−5 mm3·N–1·m–1, which was 68.8% lower than that of epoxy resin. This study presented a practical approach to improve the frictional and fire resistance of epoxy composites.

关键词: molybdenum disulfide     nickel phyllosilicate     epoxy resin     flame retardancy    

A low-density polyethylene composite with phosphorus-nitrogen based flame retardant and multi-walledcarbon nanotubes for enhanced electrical conductivity and acceptable flame retardancy

Yong Luo, Yuhui Xie, Renjie Chen, Ruizhi Zheng, Hua Wu, Xinxin Sheng, Delong Xie, Yi Mei

《化学科学与工程前沿(英文)》 2021年 第15卷 第5期   页码 1332-1345 doi: 10.1007/s11705-021-2035-0

摘要: Design and exploitation of flame retardant polymers with high electrical conductivity are desired for polymer applications in electronics. Herein, a novel phosphorus-nitrogen intumescent flame retardant was synthesized from pentaerythritol octahydrogen tetraphosphate, phenylphosphonyl dichloride, and aniline. Low-density polyethylene was combined with the flame retardant and multi-walled carbon nanotubes to form a nanocomposite material via a ball-milling and hot-pressing method. The electrical conductivity, mechanical properties, thermal performance, and flame retardancy of the composites were investigated using a four-point probe instrument, universal tensile machine, thermogravimetric analysis, and cone calorimeter tests, respectively. It was found that the addition of multi-walled carbon nanotubes can significantly improve the electrical conductivity and mechanical properties of the low-density polyethylene composites. Furthermore, the combination of multi-walled carbon nanotubes and phosphorus–nitrogen flame retardant remarkably enhances the flame retardancy of matrixes with an observed decrease of the peak heat release rate and total heat release of 49.8% and 51.9%, respectively. This study provides a new and effective methodology to substantially enhance the electrical conductivity and flame retardancy of polymers with an attractive prospect for polymer applications in electrical equipment.

关键词: MWCNTs     PEPA     electrical conductivity     flame retardant     low density polyethylene    

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propane

Jie JI, Junrui DUAN, Huaxian WAN

《能源前沿(英文)》 2022年 第16卷 第6期   页码 1017-1026 doi: 10.1007/s11708-020-0716-x

摘要: The interaction of multiple fires may lead to a higher flame height and more intense radiation flux than a single fire, which increases the possibility of flame spread and risks to the surroundings. Experiments were conducted using three burners with identical heat release rates (HRRs) and propane as the fuel at various spacings. The results show that flames change from non-merging to merging as the spacing decreases, which result in a complex evolution of flame height and merging point height. To facilitate the analysis, a novel merging criterion based on the dimensionless spacing / was proposed. For non-merging flames ( / >0.368), the flame height is almost identical to a single fire; for merging flames ( / ≤0.368), based on the relationship between thermal buoyancy and thrust (the pressure difference between the inside and outside of the flame), a quantitative analysis of the flame height, merging point height, and air entrainment was formed, and the calculated merging flame heights show a good agreement with the measured experimental values. Moreover, the multi-point source model was further improved, and radiation fraction of propane was calculated. The data obtained in this study would play an important role in calculating the external radiation of propane fire.

关键词: flame interaction     air entrainment     flame height     multi-point source model     thermal radiation    

标题 作者 时间 类型 操作

Observation of premixed flame fronts by laser tomography

MU Kejin, WANG Yue, LEI Yu, ZHANG Zhedian, NIE Chaoqun, XIAO Yunhan

期刊论文

Experimental study on premixed combustion of spherically propagating methanol-air-nitrogen flames

Xiangang WANG, Zhiyuan ZHANG, Zuohua HUANG, Xibin WANG, Haiyan MIAO,

期刊论文

Identifying combustion intermediates in premixed MTBE/gasoline/oxygen flame probed via synchrotron radiation

YAO Chunde, LI Jing, LI Qi, JI Qing, HUANG Chaoqun, WEI Lixia, WANG Jing, TIAN Zhenyu, LI Yuyang, QI Fei

期刊论文

Soot size distribution in lightly sooting premixed flames of benzene and toluene

Wang LIU, Jiaqi ZHAI, Baiyang LIN, He LIN, Dong HAN

期刊论文

Exergy losses in premixed flames of dimethyl ether and hydrogen blends

Tongbin ZHAO, Jiabo ZHANG, Dehao JU, Zhen HUANG, Dong HAN

期刊论文

Numerical simulation of laminar premixed combustion in a porous burner

ZHAO Pinghui, CHEN Yiliang, LIU Minghou, DING Min, ZHANG Genxuan

期刊论文

Transient process of methane-oxygen diffusion flame-street establishment in a microchannel

期刊论文

Modification of premixed combustion in shear layers by grid turbulence

MU Kejin, WANG Yue, ZHANG Zhedian, NIE Chaoqun

期刊论文

NC flame pipe cutting machine tool based on open architecture CNC system

Xiaogen NIE, Yanbing LIU

期刊论文

Experimental study on the laminar flame speed of hydrogen/natural gas/air mixtures

Chen DONG, Qulan ZHOU, Xiaoguang ZHANG, Qinxin ZHAO, Tongmo XU, Shi’en HUI

期刊论文

Experimental study on velocity characteristics of recirculation zone in humid air non-premixed flame

GU Xin, ZANG Shusheng, GE Bing

期刊论文

Experimental and kinetic study on laminar flame speeds of ammonia/syngas/air at a high temperature and

期刊论文

Molybdenum disulfide@nickel phyllosilicate hybrid for improving the flame retardancy and wear resistance

期刊论文

A low-density polyethylene composite with phosphorus-nitrogen based flame retardant and multi-walledcarbon nanotubes for enhanced electrical conductivity and acceptable flame retardancy

Yong Luo, Yuhui Xie, Renjie Chen, Ruizhi Zheng, Hua Wu, Xinxin Sheng, Delong Xie, Yi Mei

期刊论文

A method of determining flame radiation fraction induced by interaction burning of tri-symmetric propane

Jie JI, Junrui DUAN, Huaxian WAN

期刊论文