火焰层析成像的最新进展(英文)

To reduce greenhouse gas emissions from fossil fuel fired power plants,a range of new combustion technologies are being developed or refined,including oxy-fuel combustion,co-firing biomass with coal and fluidized bed combustion.Flame characteristics under such combustion conditions are expected to be different from those in normal air fired combustion processes.Quantified flame characteristics such as temperature distribution,oscillation frequency,and ignition volume play an important part in the optimized design and operation of the environmentally friendly power generation systems.However,it is challenging to obtain such flame characteristics particularly through a three-dimensional and non-intrusive means.Various tomography methods have been proposed to visualize and characterize flames,including passive optical tomography,laser based tomography,and electrical tomography.This paper identifies the challenges in flame tomography and reviews existing techniques for the quantitative characterization of flames.Future trends in flame tomography for industrial applications are discussed.     

介观尺度多孔介质燃烧室内火焰分布的电容层析成像(英文)

This study was conducted to investigate the characteristics of meso-scale combustion.The technique of electrical capacitance tomography(ECT) was used to locate flame position and monitor the effect corresponding to varied air/fuel ratio in a meso-scale combustor.Combustion phenomena including igniting,quenching and unsteady combustion have been visualized using ECT.The method of metallization protecting ECT sensor from high temperature damage and the novel calibration method adapted to ECT monitoring of unknown permittivity flame have been shown to be successful.At the same time,electrical nature of combustion and dielectric characteristics of hy-drocarbon flame were studied.The relationship between flame permittivity and state parameters of combustion gas was demonstrated preliminarily.     

高温烟气伴流的温度和氧浓度对甲烷/氢气扩散火焰的影响(英文)

This paper investigates the effects of coflow O2 level and temperature on diffusion flame of a CH4/H2 jet in hot coflow(JHC) from a burner system similar to that of Dally et al.The coflow O2 mass fraction(y*O2) is varied from 3% to 80% and the temperature(T*cof) from 1200 K to 1700 K.The Eddy Dissipation Concept(EDC) model with detailed reaction mechanisms GRI-Mech 3.0 is used for all simulations.To validate the modeling,several JHC flames are predicted under the experimental conditions of Dally et al.[Proc.Combust.Inst.,29(1),1147-1154(2002)] and the results obtained match well with the measurements.Results demonstrate that,when y*O2 decreased,the diffusion combustion is likely to transform from traditional combustion to MILD(Moderate or Intense Low-oxygen Dilution) combustion mode.When cof T* is higher,the temperature distribution over the whole domain trends to be more uniform.Reducing y*O2 or cof T* leads to less production of intermediate species OH and CO.It is worth noting that if y*O2 is high enough(y*O2>80%),increasing y*O2 does not cause obvious temperature increase.     

基于岭估计的化工过程测量置信水平研究(英文)

Ordinary least squares （OLS） algorithm is widely applied in process measurement, because the sensor model used to estimate unknown parameters can be approximated through multivariate linear model. However, with few or noisy data or multi-collinearity, unbiased OLS leads to large variance. Biased estimators, especially ridge es-timator, have been introduced to improve OLS by trading bias for variance. Ridge estimator is feasible as an esti-mator with smaller variance. At the same confidence level, with additive noise as the normal random variable, the less variance one estimator has, the shorter the two-sided symmetric confidence interval is. However, this finding is limited to the unbiased estimator and few studies analyze and compare the confidence levels between ridge estima-tor and OLS. This paper derives the matrix of ridge parameters under necessary and sufficient conditions based on which ridge estimator is superior to OLS in terms of mean squares error matrix, rather than mean squares error. Then the confidence levels between ridge estimator and OLS are compared under the condition of OLS fixed sym-metric confidence interval, rather than the criteria for evaluating the validity of different unbiased estimators. We conclude that the confidence level of ridge estimator can not be directly compared with that of OLS based on the criteria available for unbiased estimators, which is verified by a simulation and a laboratory scale experiment on a single parameter measurement.     

环丙沙星、诺氟沙星、氧氟沙星在1 mol·L~(-1) HCl中对碳钢的缓蚀性能及机理研究(英文)

The inhibiting effect of ciprofloxacin,norfloxacin and ofloxacin on the corrosion of mild steel in 1 mol·L-1 HCl and the mechanism were studied at different temperatures using mass loss measurement,electrochemical method,and X-ray photoelectron spectroscopy(XPS) .Effective inhibition was shown by mass loss,potentiodynamic polarization and impedance spectroscopy measurement.The corrosion rate of the metal in the mass loss measurement,and the corrosion reaction on cathode and anode in the electrochemical measurement were accelerated when temperature was increased.XPS results showed that the inhibitors adsorbed effectively on the metal surface.     

基于区间二型模糊推理的双容水箱液位控制系统研究(英文)

For dealing with large static error due to poor immunity of the traditional fuzzy control, a novel interval type-2 fuzzy control system is proposed. By extending the typical membership functions to interval type-2 membership functions, the proposed control system can efficiently reduce the uncertain disturbance from real environment without increasing the design complexity. The simulation results on the water tank level control system showed that the proposed method succeeded in better static and dynamic control with stronger robust performance than the traditional fuzzy control method.     

预测生物质颗粒热解时热损失影响的分析模型(英文)

This paper presents the combined influence of heat-loss and radiation on the pyrolysis of biomass parti-cles by considering the structure of one-dimensional, laminar and steady state flame propagation in uniformly pre-mixed wood particles. The assumed flame structure consists of a broad preheat-vaporization zone where the rate of gas-phase chemical reaction is small, a thin reaction zone composed of three regions：gas, tar and char combustion where convection and the vaporization rate of the fuel particles are small, and a broad convection zone. The analy-sis is performed in the asymptotic limit, where the value of the characteristic Zeldovich number is large and the equivalence ratio is larger than unity （i.e. u 1？ ≥ ）. The principal attention is made on the determination of a non-linear burning velocity correlation. Consequently, the impacts of radiation, heat loss and particle size as the de-termining factors on the flame temperature and burning velocity of biomass particles are declared in this research.     

基于改进GSO的裂解炉原料切换策略研究(英文)

The scheduling process of cracking furnace feedstock is important in an ethylene plant. In this paper it is described as a constraint optimization problem. The constraints consist of the cycle of operation, maximum tube metal temperature, process time of each feedstock, and flow rate. A modified group search optimizer is pro-posed to deal with the optimization problem. Double fitness values are defined for every group. First, the factor of penalty function should be changed adaptively by the ratio of feasible and general solutions. Second, the“excel-lent”infeasible solution should be retained to guide the search. Some benchmark functions are used to evaluate the new algorithm. Final y, the proposed algorithm is used to optimize the scheduling process of cracking furnace feedstock. And the optimizing result is obtained.     

SCIE中化学工程高引用文章的文献计量学分析(英文)

This study aimed to identify and to analyze characteristics of top-cited articles published in the Web of Science chemical engineering subject category from 1899 to 2011.Articles that have been cited more than 100 times were assessed regarding publication outputs,and distribution of outputs in journals.Five bibliometric indicators were used to evaluate source countries,institution and authors.A new indicator,Y-index,was created to assess quantity and quality of contribution to articles.Results showed that 3828 articles,published between 1931 and 2010,had been cited at least 100 times.Among them 54% published before 1991,and 49% top-cited articles originated from US.The top eight productive institutions were all located in US.The top journals were Journal of Catalysis,AIChE Journal,Chemical Engineering Science and Journal of Membrane Science.Y-index was successfully applied to evaluate publication character of authors,institutions,and countries/regions.     

添加剂EDTA对氢氧化镁反应结晶过程的影响(英文)

The effects of additive ethylenediaminetetraacetic acid (EDTA) on crystallization process were investigated by the induc-tion time of MgSO4-NaOH system. Nucleation and growth rates, growth mechanism and particle size distribution of magne-sium hydroxide precipitation were involved with. The induction time in unseeded and seeded precipitation of magnesium hydroxide with and without additive EDTA was measured. The conductivity method was used to determine the induction period. Theoretical relations of the induction time and supersaturation ratio for different growth mechanisms and a combined analysis on the induction time were applied to determine nucleation and growth rates. The growth mechanism of magnesium hydroxide precipitation was dis-closed by analyzing the experimental data with and without additive. The analysis on induction time indicated that additive EDTA had a significant influence on both nucleation and growth of magnesium hydroxide precipitation. The mechanism underlying the effect of EDTA on crystal growth was 2-dimension nucleation-mediated growth model.     

The Generation of a Reduced Mechanism for Flame Inhibition by Phosphorus Containing Compounds Based on Path Flux Analysis Method

In order to analyze the complex chemical kinetic mechanism systematically and find out the redundant species and reactions, a numerical platform for mechanism analysis and simplification is established basing on Path Flux Analysis （PFA）. It is used to reduce a detailed mechanism for flame inhibited by phosphorus containing compounds, a reduced mechanism with 65 species and 335 reactions is obtained. The detailed and reduced mechanism are both used to calculate the freely-propagating premix C3H8/air flame with different dimethyl methylphosphonate doped over a wide range of equivalence ratios. The concentration distributions of free radicals and major species are compared, and the results under two different mechanisms agree well. The laminar flame speed obtained by the two mechanisms also matches well, with the maximum relative error introduces as a small value of 1.7%. On the basis of the reduced mechanism validation, the correlativity analysis is conducted between flame speed and flee radical concentrations, which can provide information for target species selection in the further mechanism reduction. By analyzing the species and reactions fluxes, the species and reaction paths which contribute the flame inhibition significantly are determined.     

聚合物的阻燃及阻燃剂的研究进展

文章综述了卤系、磷系、无机阻燃剂、纳米复合阻燃聚合物的阻燃机理及其研究进展。并提出综合使用多种阻燃方法正成为聚合物阻燃的研究方向。     

高分子材料无卤阻燃剂的研究现状

综述了高分子材料无卤阻燃剂的种类和阻燃机理;重点介绍了无机物阻燃剂、无卤膨胀型阻燃剂、有机硅阻燃剂等无卤阻燃剂的开发以及在高分子材料中的应用研究现状;并对无卤阻燃剂的发展方向进行了展望。     

阻燃剂应用研究综述

综述了主要无机和有机类阻燃剂的阻燃机理及应用,介绍了国内外目前在阻燃剂方面研究的新情况及广泛应用于阻燃的技术,并展望了阻燃剂的未来发展趋势.     

绿色阻垢剂聚环氧琥珀酸的阻垢机理的研究

聚环氧琥珀酸（PESA）是一种无磷、非氮且生物降解性好的绿色水处理剂。本文通过测定模拟工业循环水过饱和水溶液的电导率,考察了PESA对碳酸钙垢沉积的影响,并通过红外光谱和扫描电镜分析手段研究了加入不同浓度PESA碳酸钙垢晶型的变化。在此基础上,研究了聚环氧琥珀酸的阻垢机理。     

新型丙纶无卤阻燃剂阻燃机理的研究

用裂解气相色谱-质谱(PyGC-MS)法研究阻燃丙纶的热裂解,分析其高温裂解产物,从而推测阻燃材料受热分解时所发生的反应,推断此无卤阻燃剂的阻燃机理。研究结果表明,此阻燃剂主要是通过阻隔降温及捕获活化自由基的方式来实现阻燃。     

新型硅-磷复合膨胀型阻燃剂正交实验研究及阻燃机理分析

本文基于正交实验探索了氯化镧、正硅酸乙酯(TEOS)、磷酸二氢铵、尿素、季戊四醇和反应介质的pH值对阻燃剂阻燃效果的影响主次顺序,采用测量极限氧指数(LOI)和垂直燃烧仪分别评价了该新型硅-磷复合膨胀型阻燃剂的性能,通过SEM和TG分析其阻燃机理.结果表明在较弱的酸性条件下通过溶胶-凝胶法可制备出性能优异的阻燃剂,不同因素对阻燃效果影响不同,B(m(磷酸二氢铵)∶2m(季戊四醇)∶2m(尿素))＞D(pH值)＞A(阻燃体系/TEOS)＞C(氯化镧/阻燃体系).当A3=30％,B1=3∶2∶1,C3=3％,D4=6时,得到优方案,阻燃效果最好,经优方案处理的棉织物氧指数提高至35.4％;它们在棉布燃烧时可发挥协同阻燃性,形成具有隔热隔氧性能的致密膨胀层,并释放阻燃性气体.     

膨胀型防火涂料研制及阻燃机理研究进展

膨胀型防火涂料是目前国内外使用最广泛的一种防火涂料,其特点是在火焰或高温作用下,可产生比原涂层厚几十甚至上百倍的不易燃的海绵状炭质层,有效地阻止了外部热源的作用,同时,产生不燃性气体,从而起到防火、阻燃作用,近年来逐渐成为国内外关注的一个研究热点.对膨胀性防火涂料的制备及阻燃机理给予综述.     

原位FTIR研究含磷阻燃PET的阻燃机理

采用原位傅里叶变换红外光谱并结合热分析等手段研究了含磷阻燃聚酯的热解过程。通过与未加阻燃剂聚酯的比较,得出阻燃剂分子抑含磷阻燃聚酯聚合物中肪肪族ＣＨ２基的氧化,捕获热产生的可燃物,促使聚酯成碳形成的惰性隔层,从而达到阻燃目的。     

阻垢剂作用机理研究进展

本文回顾了阻垢剂的发展历程 ,并对阻垢性能研究与评价方法、阻垢剂对成垢盐沉积抑制作用的研究状况以及阻垢作用机理作了综述 ,在此基础上提出了有待进一步研究的几个问题。