SOF-FTIR在化工厂区氨气排放通量测量中的应用

介绍了一种化工厂区污染气体排放通量实时监测的新方法,即太阳掩星法傅里叶变换红外光谱技术(SOF-FTIR),提出了复杂条件下的背景谱、测量谱和污染区域周边大气透过率谱获取模型。通过对欲监测的污染源区域周边做闭合环路连续测量以获得测量光谱,最终应用非线性最小二乘拟合算法对污染源区域污染气体的柱浓度信息进行反演,并结合实验时气象参数以及GPS信息得到该区域污染气体的排放通量。运用此方法实际遥测了某化工厂区氨气的排放情况,并对氨气气体浓度分布及排放通量进行了定量分析。相对于传统的FTIR监测方法,该方法操作简单、机动性强,在污染气体区域监测以及其他污染源污染排放应急监测等应用领域具有良好的应用前景。     

奶牛场氨排放特征的光谱检测

为实现奶牛场氨气减排,改善生态环境,需要在线监测氨挥发浓度并准确揭示氨排放特征。采用开放式可调谐半导体激光吸收光谱 (TDLAS) 技术设计了开放式氨气在线监测系统,结合反演式气体扩散技术开展相关研究,于2013年秋季和冬季在保定市某奶牛厂进行了氨排放浓度在线监测和排放特征分析工作。监测结果表明,秋季氨气浓度峰值为6.11×10-6%,冬季氨气浓度峰值为6.56×10-6%,氨浓度具有日变化趋势,基本呈白天浓度低,夜晚浓度高的特点。由反演气体扩散模型得到秋冬季氨排放特征,氨排放峰值均出现在中午,秋季氨排放速率为1.48～130.6 kg/head/hr,冬季氨排放速率为0.004 5～43.32 kg/head/hr,秋季的排放速率高于冬季,说明奶牛场尺度下的氨排放存在一定的季节性差异。该方法可以有效获得大范围、高灵敏、免采样、快速气体排放特征结果,为奶牛厂的氨排放监测和科学养殖提供技术支持。     

温室气体排放权及其交易的会计确认与计量

温室气体排放权及其交易的会计处理主要涉及排放权资产、排放负债的确认及计量模式的选择.当前,这一会计实务呈现多样化,影响了财务信息的可比性,迫切需要统一.统一的会计实务是,排放权资产应当作为独立的资产确认,并在财务报表中单独列示;相关负债应在企业加入减排计划时全额确认,并在财务报表中单独列示;排放权资产、排放负债及政府补...     

排放源颗粒物浓度及粒径连续监测技术的研究

１前言我国实施了“主要污染物排放总量控制”的环境控制战略，把污染排放总量逐级下达到每一个排放源。为此，亟需解决排放源颗粒物浓度的测量技术。取样法（ＳａｍＰｌｉｎｇ）不能连续测量，测量周期也长，操作繁杂，劳动强度大，使得对排放源的复检率很低，测量误差也较高【‘］。浊度法（ＯＰａｃｉｔｙ）及近期发展的杂散光法（ＳｔｒａｙＬｉｇｈｔ）【’］，虽易于实现连续测量，但其测量结果为浊度或散射光强，烟尘浓度值则需通过标定的方法才能得到。实际上，浊度和散射光强不仅与烟尘的浓度相关，还要受到烟尘颗粒的粒径及折射率…     

微波消解-电感耦合等离子体-发射光谱法研究藏香燃后起源颗粒态砷镉铜铅的排放特征

燃香产生大量的颗粒物和挥发性物质已经成为室内空气污染的重要来源之一。目前有关燃香对局部大气环境影响的研究主要集中在燃香起源颗粒物浓度、挥发性气体、有机污染物等含量的测定。有关燃香所排放颗粒态重金属的排放率、排放因子以及所排放的颗粒态重金属对室内空气环境质量影响研究未见报道。使用微波消解仪对9种(S1—S9)线型藏香样品及其燃烧后所释放的总悬浮颗粒物进行程序升温消解，并采用电感耦合等离子体发射光谱(ICP-OES)分别在波长188.980, 214.439, 327.395及220.353 nm下对藏香及其燃烧所释放的总悬浮颗粒物中As, Cd, Cu和Pb含量进行检测，分析藏香燃后起源颗粒态重金属的排放特征，为评估室内藏香密集性使用所排放的颗粒态重金属对人体健康的潜在影响以及制定藏香重金属限量标准提供参考。实验发现：(1)不同种类藏香样品中四种重金属含量不同，平均含量从高到低依次为Cu, Pb, As和Cd元素。不同种类藏香样品中Cd和Pb的来源相似、而As和Cu的来源明显不同。(2)不同种类藏香燃烧后烟尘量不同，最高为94.75 mg·kg^-1,最低为38.52...     

不同堆积方式下碳黑颗粒氧化特性的实验研究

本文将自由堆积和DPF中错流沉积碳黑颗粒的氧化再生进行对比，从气体排放、颗粒物排放、氧化再生效率以及能量利用率进行分析，探索DPF再生时气体和颗粒排放规律和特性。实验结果表明：自由堆积碳黑颗粒受热升温快，生成的CO/CO₂气体很快达到峰值，但氧扩散受限，气体达到峰值后缓慢下降。DPF载体传热缓慢，错流沉积碳黑颗粒氧化产生气体的出峰时间延后，但来流充分与颗粒接触，生成气体峰值大，再生迅速且效率高，排出的颗粒物数量浓度升高，且存在大粒径颗粒物释放现象。提高温度，两种堆积方式的氧化再生效率增加，实时效能比先升高后下降，存在最佳的加热时间。本文研究结果将为探索DPF再生时出口颗粒排放特性，颗粒物来源分析奠定理论基础和实验参考。     

燃煤锅炉中痕量元素排放因子的研究

目前国内外对煤燃烧过程中痕量元素的排放和控制作了大量的研究工作,但是对痕量元素的排放因子的研究却鲜见报道。本文通过实验数据和一些经验数据对痕量元素排放因子进行了研究,了解了燃煤电厂锅炉容量和负荷对痕量元素排放因子的影响,并考察了除尘装置及脱硫装置等与痕量元素排放因子的关系,结果发现大容量锅炉痕量元素排放因子要相对小一些,且随着负荷降低,痕量元素排放因子会增加。     

基于红外掩日通量法(SOF)污染源排放气体浓度时空分布反演算法研究

介绍了在傅里叶变换红外光谱(FTIR)技术基础上发展起来的一种监测污染源有害气体排放率的新方法——红外掩日通量(solar occultation flux,SOF)法.在理论上建立了太阳辐射两层传输模型,根据比尔定律阐述了计算污染物透过率的方法.详细介绍了如何从HITRAN,NIST和QAsoft三种红外数据库中提取气体标准吸收截面.介绍了基于Levenberg-Marquardt非线性最小二乘法反演污染气体柱浓度的算法和污染源气体排放率计算算法.介绍了整套装置的组成部分和太阳跟踪装置的结构.对合肥某一化肥厂的氨气排放进行了测量,从实验结果可以看出,测量的柱浓度分布准确地反应了污染物排放和扩散情况,证明了污染源排放气体浓度时空分布反演算法的正确性.     

北京机动车限行期间苯和甲苯的DOAS测量

基于差分光学吸收光谱(DOAS)技术在北京机动车限行期间8月7日到28日对苯和甲苯进行连续监测,获取苯、甲苯的变化特征,分析交通排放苯、甲苯和车流量关系. 监测结果表明,整个交通管制期间,监测点苯与甲苯相关系数为0.8,且二者比值为0.43～0.50,充分证明苯系物具有同源性. 限车时段苯的浓度下降11.4%,甲苯下降12.8%,而车流量下降11.8%,因此苯和甲苯是北京机动车排放的主要来源.     

温室气体通量测量方法及进展

分析了国内外主要的温室气体通量测量方法，包括针对地球生态系统通量的测量方法和针对人为排放通量的测量方法。梳理了地基原位通量测量网络、地基和星载被动遥感技术和以激光雷达为代表的主动遥感技术的研究现状与进展，分析了当前测量技术对人为碳排放的探测能力。结合国内外发展趋势，展望了为满足全球和区域人为碳排放监测的需求，需要同化原位探测与主动遥感探测数据、通过科学的卫星组网提高时空分辨率并建立不同尺度的模型。     

被动式OP-FTIR的新近发展

被动式OP-FTIR是一种开路FTIR技术,它具有OP-FTIR的所有优点,而且在缺乏背景信息的情况下,有对准任意方向收集数据的能力,是一种可移动、快速的遥测手段。文中给出了被动式OP-FTIR在高海拔大气污染物测量、有毒气体自动识别、热耗气体测量(包括飞行器尾气测量、烟囱释放化学烟羽测量和遥测火山发射物)、温度及燃烧产物的测量(包括云层温度测量)及军事上等几个方面的新近应用。随着FTIR和计算机技术的不断发展,被动式OP-FTIR将在环境监测、航空航天、发动机排放、燃烧和军事等方面,有着非常广阔的应用前景。     

Laser Stark Spectroscopy and Isotopic Separation

A potentially useful scheme for photoselective isotope enrichment is presented. The selective laser excitation step is accomplished by utilizing the Stark effect to shift molecular transitions into resonance with laser frequencies. The method is demonstrated for isotope separation of ¹³C, ¹⁵N and ²H. Laser Stark spectroscopy can sensitively detect as few as 10⁹ molecules in the optical path, thus the isotopic separation can be achieved from industrial sample mixtures containing natural abundances. A comparison of the isotopic enrichment efficiency using the present method of “exact” resonance and the previously used method of “near” resonance excitation is also given.     

航空发动机尾气的FTIR被动遥感

针对航空发动机排放尾气传统的插入式采样分析技术难度大、设备结构复杂、测量成本高、具有一定危险等缺点,将快速、机动、低成本的非插入式测量方法——被动式傅里叶变换红外光谱(FTIR)遥感技术引入到航空发动机尾气监测当中。讨论了FTIR被动遥感的原理,介绍了FTIR光谱仪系统的仪器响应函数、红外辐射光谱能量分布以及气体浓度的算法模型。利用TENSOR27型FTIR光谱仪遥测某航空发动机排放尾气,获得一系列不同推力下红外发射单通道光谱图。通过对红外发射光谱的定性定量分析,计算出四种不同推力下CO₂,CO和NO的气体组分浓度。利用遥感FTIR方法监测航空发动机排放气体组分浓度的研究在国内航空领域尚处于探索阶段,试验中航空发动机的排放发射光谱及计算结果是首次公开发表。实验同时也表明该技术在航空发动机尾气监测方面具有极大的应用前景。     

A finite volume method for electrostatic three species negative corona discharge simulations with application to externally charged powder bells

A three species model for steady-state negative corona discharge is studied. Ionization, attachment, and recombination reactions are modeled. A novel unstructured finite volume algorithm to solve the equations is presented, using the secondary emission of electrons from the cathode to set boundary values for the electrons.To show the usefulness of the method for industrial applications it is used to characterize the electrostatic properties of an externally charged rotary powder bell used in the automotive industry. Experimental current density profiles are reconstructed with good accuracy, which validates the model and the method with real experimental data.     

Sources of Environmental Pollution in Ankara (Turkey): Geochemistry and Traffic Effects—PEDXRF Applications

Road dusts were collected from the main streets in the vicinity of Ankara, the capital city of Turkey, including exhaust dust samples from the different fuel-based motor vehicles and sample pieces of brake pads to characterize their metal compositions by polarized energy-dispersive X-ray fluorescence (PEDXRF) spectrometry. Road dust samples were gathered by a vacuum dust sweeper from nine different densely populated residential settlement regions of Ankara, far from large industrial plants. Heavy metal contents of the road dusts were analyzed during the summertime to determine the metal pollution due to the motor vehicle exhaust, abrasion of brake pads, and lithology, ignoring the industrial and heating sources of pollution. The results of the analysis showed that the elements of Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sn, Pb, and Th in road dust samples were not derived from the lithology and industrial plants but from the motor fuel exhausts and brake pad abrasion. Generally, urban environmental pollution due to the toxic trace metals from traffic is harmful for the human health as well as the ecosystems near Ankara.     

Simplified mesh techniques for design of beam-shaping diffractive optical elements

This paper describes a simplified mesh generation technique that is based on the finite element method of calculation of beam-shaping diffractive optical elements (DOEs). The mesh generation technique uses the inherent symmetry of the incident beam to generate a mesh. Using the meshes so generated, DOEs that convert a Gaussian intensity beam to one of a specified shape, are calculated. Simulations of the results of such beam-shaping elements will be presented. Such elements have uses in industrial and medical applications where both the shape as well as the intensity distribution on the material that is to be processed is very important. For example, in industrial applications the beam may be used to uniformly heat up a specific area in which case the intensity has to be uniform across the beam. The Gaussian intensity variation of a laser has to be converted to a flat-top beam in order to achieve this. To reiterate, beam shaping refers to changing both the intensity distribution and the shape of the beam. Experimental results of the fabricated gratings will also be presented. These results will include experimental data on the method of additive lithography which can be used to improve the efficiency of DOEs.     

SO2气体排放的紫外成像遥感监测

工业烟囱及船舶尾气中SO2气体排放是造成大气污染的重要因素。SO2容易被氧化生成硫酸雾或硫酸盐气溶胶,产生酸雨,严重危害大气生态环境平衡及人类健康。现有的SO2光学遥感测量技术,如拉曼散射激光雷达、差分吸收激光雷达(DIAL)、傅里叶变换红外吸收光谱(FTIR)、紫外差分吸收光谱(DOAS)、高分辨光谱成像等,难以兼顾气体污染监测对高时间分辨率、高空间分辨率以及便携机动等应用需求。近年来,紫外SO2相机成像探测因探测精度高、实用性强得到迅速发展,该技术时间分辨率高、空间分辨力强,能从解析图像中直观在线获取污染气体浓度在空间的二维分布及随时间的排放率,对于监测环境污染有重要作用。基于紫外SO2相机成像探测技术,围绕SO2柱浓度探测的测量原理及影响因素、仪器设计及实验方法、反演算法及结果比对等方面开展研究。取得的成果主要有:(1)利用窄带滤光片的窄波窗口,用紫外相机测量310 nm附近的SO2紫外吸收,建立了紫外成像遥感监测理论模型,介绍了紫外成像遥感检测获取SO2浓度图像的测量原理;(2)将滤光片放置镜头前后,讨论了不同入射角对滤光片中心波长及透过率曲线的影响,发现滤光片放置镜头后,相机系统对SO2的灵敏度受入射角影响更小,对SO2浓度图像的反演误差更小;(3)分析了太阳高度角对SO2浓度图像反演的影响,阐明了SO2浓度反演曲线实时校准的不可或缺性;(4)通过理论分析设计出了紫外成像遥感探测装置,开展了基于紫外成像遥感监测SO2气体排放的实验研究,通过2-IM法拟合出了人工天空背景,获得了SO2光学厚度图像,利用标准泡进行校准,反演出了SO2浓度图像;(5)采用DOAS技术对SO2气体排放进行监测,与紫外成像遥感获得的SO2浓度进行对比表明,两方法实验结果所计算得到的浓度信息趋势相一致,从而证明紫外成像遥感监测技术测量结果的准确性,同时展现了该技术在工厂烟囱及船舶尾气污染排放遥感监测中的巨大应用前景。     

Influence of soot particle aggregation on time-resolved laser-induced incandescence signals

Laser-induced incandescence (LII) is a versatile technique for quantitative soot measurements in flames and exhausts. When used for particle sizing, the time-resolved signals are analysed as these will show a decay rate dependent on the soot particle size. Such an analysis has traditionally been based on the assumption of isolated primary particles. However, soot particles in flames and exhausts are usually aggregated, which implies loss of surface area, less heat conduction and hence errors in estimated particle sizes. In this work we present an experimental investigation aiming to quantify this effect. A soot generator, based on a propane diffusion flame, was used to produce a stable soot stream and the soot was characterised by transmission electron microscopy (TEM), a scanning mobility particle sizer (SMPS) and an aerosol particle mass analyzer coupled in series after a differential mobility analyzer (DMA-APM). Despite nearly identical primary particle size distributions for three selected operating conditions, LII measurements resulted in signal decays with significant differences in decay rate. However, the three cases were found to have quite different levels of aggregation as shown both in TEM images and mobility size distributions, and the results agree qualitatively with the expected effect of diminished heat conduction from aggregated particles resulting in longer LII signal decays. In an attempt to explain the differences quantitatively, the LII signal dependence on aggregation was modelled using a heat and mass transfer model for LII given the primary particle and aggregate size distribution data as input. Quantitative agreement was not reached and reasons for this discrepancy are discussed.     

Glow Discharge Characteristics of Hollow Needle-Plate Electrode in Atmospheric Pressure ArgonSCIEI北大核心CSCD

Atmosphere pressure uniform plasma has the broad application prospect in the industrial field. Using hollow needle cathode - plate anode device excited by direct-current voltage, a uniform and stable glow discharge is generated at atmospheric pressure in ambient air with argon used as working gas. The influence of the experimental parameters (including gas flow rate and the gas gap width) on discharge has been investigated by optical method. It can be found that a glow-discharge plasma column can bridge the two electrodes. The plasma column is uniform, and no filaments can be discerned. Near the plate electrode, the diameter of the plasma column is largest of all positions. The maximal diameter of the plasma column increases with increasing the discharge current or the gas flow rate. Through electrical method, the voltage-current characteristic has been investigated. It has been found that the discharge voltage decreases with increasing the current which is similar with the characteristic of glow discharge in low pressure. It increases with increasing the gas gap width or the gas flow rate. By analyzing the optical emission spectrum scanning from 330 to 450 nm emitted from the direct-current glow discharge, the molecular vibrational temperature and the intensity ratio of spectral lines I-391.4/I-337.1 have been investigated as functions of the gas flow rate and gas gap width. Results indicate that both the vibrational temperature and the intensity ratio of spectral lines I-391.4/I-337.1 decrease with increasing the gas flow rate or the gas gap width. In addition, the molecular vibrational temperature and the intensity ratio of spectral lines I-391.4/I-337.1 have been investigated in spatial resolution along the direction of gas flow(plasma column axial), and give a qualitative analysis as well. It is found that the vibrational temperature and the average electron energy increase with increasing the distance from the hollow needle cathode. These results are important to the industrial applications of glow discharge.     

空心针-板电极大气压氩气辉光放电的特性研究

大气压均匀放电等离子体在工业领域具有非常广泛的应用前景,它是利用直流电源激励的空心针-板放电装置,以氩气为工作气体在大气压空气中产生均匀稳定的放电。对氩气流量和气隙间距对辉光放电发光特性的关系进行了研究,结果表明放电所产生的等离子体柱连接两个电极,发光较为均匀(观察不到放电丝)。在板电极附近放电等离子体柱直径最大,最大直径随着电流和气流的增大而增大。放电伏安特性研究发现,与低气压辉光放电相类似,两电极间的电压随着电流的增大而减小,并且随气流和气隙间距的增大而增大。对该大气压直流均匀放电在扫描范围为330～450 nm的光学发射光谱进行分析,获得了放电等离子体的分子振动温度和谱线强度比I_391.4/I_337.1随氩气流量和气隙间距的变化关系。I_391.4/I_337.1均随流量和气隙间距的增大而降低。对等离子体柱的I_391.4/I_337.1沿气流方向(等离子体柱轴向)进行了空间分辨测量,并进行了定性分析,结果表明,振动温度及电子平均能量随着远离空心针口距离的增大而增大。这些结果对大气压辉光放电在工业中的应用具有重要意义。