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The effects of the mat preprocessing method on total volatile organic compounds (TVOC) emission of car mat are studied in this paper. An appropriate TVOC emission period for car mat is suggested. The emission factors for total volatile organic compounds from three kinds of new car mats are discussed. The car mats are preprocessed by washing, baking and ventilation. When car mats are preprocessed by washing, the TVOC emission for all samples tested are lower than that preprocessed in other methods. The TVOC emission is in stable situation for a minimum of 4 days. The TVOC emitted from some samples may exceed 2500μg/kg. But the TVOC emitted from washed Polyamide (PA) and wool mat is less than 2500μg/kg. The emission factors of total volatile organic compounds (TVOC) are experimentally investigated in the case of different preprocessing methods. The air temperature in environment chamber and the water temperature for washing are important factors influencing on emission of car mats. 相似文献
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The field and laboratory emission cell (FLEC) is becoming a standard method of characterizing pollutant emissions from building materials. It is significant to use the emission profiles from FLEC to scale the emissions of building materials in real buildings. The dynamics of mass transfer in such an FLEC are the key to perform this task. In this study, the mass transfer mechanisms of the total volatile organic compounds from a wet painting in an FLEC are experimentally and numerically investigated. A three-dimensional mass transfer model, which takes into account the convective mass transfer between the material and the air, the diffusion in the paint film and in the substrate, is developed. The emissions from a water-based emulsion paint are quantified to assess the model. The concentration fields in the film and substrate are calculated to demonstrate the processes of internal volatile organic compounds diffusion. 相似文献
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对大连石化聚丙烯装置尾气排放和回收现状进行了分析,通过对全厂尾气排放管网进行优化设置,把全厂尾气中的可回收气体(主要是丙烯、丙烷等有机蒸气)和不可回收气体(主要是氮气、乙烷等不凝气)分开排放,可回收气体排人气柜。尾气升压冷凝回收后,有机蒸气回收率为89.73%,但升压冷凝后的排空气中仍含有58%左右的C3H6和C3H8,再利用膜分离技术对排空气中的有机蒸气进行回收,丙烯单体回收率达到96.21%。通过优化排空管网设置、升压冷凝回收和膜分离回收等3种技术手段的综合运用,聚丙烯装置尾气中有机蒸气的回收率达到了99.59%,避免了装置尾气排放造成的环境污染.同时优化了资源,降低了生产成本。 相似文献
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基于恒温热重-燃烧污染物在线监测系统,通过对NO瞬时释放曲线的分析,并结合燃烧反应动力学计算,研究了恒温条件下燃烧环境温度对准东煤燃烧过程中NO释放特性的影响。结果表明:随温度升高,单煤和混煤燃烧过程中NO的释放时间会显著降低,释放速度显著提高;煤种成分的差异会导致NO释放特性的差异,固定碳挥发分的质量分数对NO释放有影响,而灰分的质量分数对NO释放无影响,当高固定碳、高挥发分的煤与低固定碳、低挥发分的煤进行掺混燃烧时,混煤的NO释放量和释放速率会降低。当燃烧过程中掺混北山煤时,混煤NO释放量低,释放速率慢,可以看作是一个较为优良的混煤掺烧方案。 相似文献
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M. Ghanashyam Krishna M. Rajendran D. R. Pyke A. K. Bhattacharya 《Solar Energy Materials & Solar Cells》1999,59(4):337
The spectral emissivity of Yb3+ in a series of compounds has been investigated to study the effects of crystal structure type, chemical environment, ytterbium concentration, impurity concentration and temperature on the spectral radiant intensity of the selective emitter peak and emitted power from the material. A figure of merit has been defined which enables the compounds to be ranked for application in a practical thermophotovoltaic energy conversion device. It is shown that significant selective emission can be achieved from compounds in which the Yb3+ concentration is as low as 10 mol%. Apart from pure Yb2O3, the compounds Yb3Al5O12, YbNbO4 and Y0.9Yb0.1O1.5 are found to have emission spectra suitable for efficient matching to silicon photovoltaic cells. 相似文献
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Mazhar Hussain Ya-Ling He A. A. Mohamad 《Numerical Heat Transfer, Part B: Fundamentals》2015,67(3):211-230
A new hybrid algorithm based on the lattice Boltzmann method (LBM) and the finite-volume method (FVM) is proposed for numerically calculating the emissions of volatile organic compounds (VOCs) from building materials and predicting their space distribution. Most building envelopes are comprised of single as well as multilayer materials, with some of them being porous and others nonporous. First, only the LBM is used to calculate the VOC concentration in airtight and ventilated chambers with constant as well as variable ventilation. For multilayer materials, including both porous and nonporous, half-lattice division methodology in the LBM is used, which ensures flux continuity at the interfaces. Good agreement is found between computed results and experimental data available in the literature. The effect of variable ventilation is also studied for both types of sequences of porous/nonporous layers. Then the LBM coupled with the FVM is used to investigate the VOC concentration distribution in the room emitted from styrene-butadiene rubber (SBR) plate, and good agreement is found between obtained results and those already published. The hybrid algorithm with multilayer approach is also used to conduct a detailed study of the effect of different ventilation organizations on the concentration in the room air, and the best one is found by the simulation. 相似文献
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煤粉燃烧时NOx析出规律的试验研究 总被引:6,自引:2,他引:4
在一维沉降炉上系统地考察了煤粉燃烧时NOx的沿程排放特性及其影响因素.试验表明,NOx的生成与炉温、煤粉粒度、煤种、过量空气系数等因素密切相关;在其它条件相同的情况下,NOx的生成浓度随过量空气系数的增大而增大;随着温度的升高略有增大;挥发分含量、氮含量高的煤种NOx的生成也相对较多;煤粉燃烧存在一个临界粒径(dc).当d>dc时,其NOx浓度随粒径的增大而减小;当d<dc时,其NOx浓度随粒径的减小而减小.(通过对NOx生成规律的分析研究,对今后低NOx燃烧技术的改进具有一定的指导意义.) 相似文献
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Didem N. Inceoğlu İsmail Özbay Aykan Karademir 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2019,41(11):1305-1314
In steel industry, hard coal is proceeded in coke ovens to produce metallurgical coke. In this process, some additives such as petroleum coke (petcoke) are used for optimizing operational cost. For the determination of addition ratio of petcoke, it is important not to disrupt coke quality, especially with respect to coke reactivity index and coke strength after reaction, while another important point is emission quality. In this study, petcoke gas (PCG) emitted from the thermal decomposition of petcoke at the maximum thermal decomposition temperature is characterized for volatile organic compounds (VOCs) and polyaromatic hydrocarbons (PAHs) and the results are assessed in comparison to the coke oven gas (COG). First, the petcoke sample is heated for gasification by using thermal gravimetric analyzer-DTA device. The gas in the temperature range of 490–510°C, where the highest gasification acceleration occurs, is taken from the funnel and transferred to GC-MS device by using a headspace gas sampler unit. The total VOC concentration in PCG and COG is found to be 121.76 ppm and 5,774.76 ppm, respectively, while the total PAH concentrations are 0.625 and 0.495 ppm, respectively. The results show that using petcoke in coal blend seems to be a more environment-friendly process with respect to a significant decrease in VOC emissions. 相似文献
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目前,通用的量化二氧化碳排放方法是IPCC排放因子法,但IPCC的排放因子是否适用于我国的排放源有待商榷。利用现场监测的烟道内的温度、压力、二氧化碳浓度、一氧化碳浓度、烟气流速、水蒸气体积百分比等参数,采用质量比法、时间比法、负荷法以及IPCC排放因子法等多种方法,对某企业不同时间段内的二氧化碳排放情况进行量化。结果表明,如果国内企业采用国际通用的量化二氧化碳排放方法,则得到的二氧化碳排放量偏大。为了能更准确地获得燃烧排放源的二氧化碳排放情况,需要采用现场监测的方法。质量比法与IPCC排放因子法的量化结果,其准确性严重依赖于燃料计量数据的准确性,不推荐采用。时间比法的量化结果虽然优于质量比法,但不适合用于量化较长时间段内的二氧化碳排放量。负荷法由于考虑了负荷的影响,其量化结果更为可靠。建议企业通过监测手段,采用负荷法量化燃烧排放源的二氧化碳排放量。为了尽可能减小由客观因素带来的排放量的不确定性,建议选择不同时间段、不同工况多次监测量化燃烧排放源某年度的二氧化碳排放量。 相似文献
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Mariano Sirignano Angelo Collina Mario Commodo Patrizia Minutolo Andrea D’Anna 《Combustion and Flame》2012,159(4):1663-1669
Spectral and time-resolved fluorescence and incandescence measurements are used to identify aromatic compounds and particles in an atmospheric-pressure opposed-flow flame of ethylene. The fourth harmonic radiation, at 266 nm, of a Nd–YAG laser is used to excite electronic transitions in aromatic intermediates resulting in different laser induced emission signals. Time-resolved analysis of the emission spectra is performed to obtain information about the structure of the compounds responsible for emission signals. Four fluorescence bands in the UV and visible range and a continuum with a maximum at larger wavelengths, attributed to incandescence radiation by solid particle, have been identified in the collected spectra. On the basis of fluorescence emission spectra and fluorescence lifetimes, two different types of high-molecular mass aromatic compounds are individuated in the flame: highly-packed, sandwich-like structures (cluster of PAHs held together by van der Waals forces) and more loose aromatic moieties linked together by σ-bonds, such as the aromatic–aliphatic linked hydrocarbons. The first class of particles has been found in the fuel zone and across the stagnation plane of the opposed-flow flame. In this region (<1500 K) coagulation of aromatics is the leading mechanism forming high-molecular mass structures. The second class of particles is preferentially formed in the region close to the oxidizer side characterized by high temperatures (>1500 K) and growth of aromatics enhanced by the high concentration of small radicals and gas-phase polycyclic aromatic hydrocarbons. 相似文献
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燃煤是汞最大的排放源,而汞又是煤中最易挥发的重金属元素之一,由于汞的剧毒性、积累性及停留时间等特点,汞污染问题引起越来越多人的重视。文中论述了汞的排放形态及其特性,并分析了燃烧前脱汞、燃烧中脱汞和燃烧后脱汞等方面的技术,燃烧后脱汞应用较广泛。 相似文献
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One of the strategies being developed in Nigeria to increase the presently installed electricity generation of 6159 MW to the required 30,000 MW is the adoption of electric thermal plants. An emission factor approach is used in this paper to study the emission of uncontrolled air pollutants from all the existing and proposed thermal plants in the country. Calculations are performed to study the distribution of carbon monoxide (CO), oxides of nitrogen (NOX), particulate matters (PM), sulphur dioxide (SO2), and volatile organic compounds (VOCs). The estimated emissions ranges are 978–24,607, 1635–41,148, 37–924, 19–472, and 11–286 ton/annum for CO, NOX, PM, SO2, and VOCs, respectively. The present locations of these plants across the country are characterized by skewed emission distribution both per capita and across the land. Given the potential environmental and health impacts of these emissions, several measures are suggested to reduce future impacts and assist the country in achieving sustainable development. 相似文献
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In this work, the flame characteristics of torrefied biomass were studied numerically under high-temperature air conditions to further understand the combustion performances of biomass. Three torrefied biomasses were prepared with different torrefaction degrees after by releasing 10%, 20%, and 30% of volatile matter on a dry basis and characterized in laboratory with standard and high heating rate analyses. The effects of the torrefaction degree, oxygen concentration, transport air velocity, and particle size on the flame position, flame shape, and peak temperature are discussed based on both direct measurements in a laboratory-scale furnace and CFD simulations. The results primarily showed that the enhanced drag force on the biomass particles caused a late release of volatile matter and resulted in a delay in the ignition of the fuel–air mixture, and the maximum flame diameter was mainly affected by the volatile content of the biomass materials. Furthermore, oxidizers with lower oxygen concentrations always resulted in a larger flame volume, a lower peak flame temperature and a lower NO emission. Finally, a longer flame was found when the transport air velocity was lower, and the flame front gradually moved to the furnace exit as the particle size increased. The results could be used as references for designing a new biomass combustion chamber or switching an existing coal-fired boiler to the combustion of biomass. 相似文献
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为了改善工业煤粉锅炉的NO_x排放特性并保证其燃烧效率,对某新型空气分级燃烧器进行了现场试验.通过改变煤种、过量空气系数及三次风开度,分析了锅炉NO_x及CO排放质量浓度的变化规律,同时采用反平衡法对锅炉的热效率进行了测算.试验结果表明,工业煤粉锅炉能达到较高的热效率;煤中氮含量及挥发分含量与NO_x的生成具有一定的相关性,氮含量越高,NO_x排放质量浓度越高,挥发分含量越低,NO_x排放质量浓度越高;过量空气系数和三次风开度不仅影响锅炉燃烧效率,而且对NO_x排放的影响也较为显著.研究发现,试验锅炉的排烟氧含量(质量分数)应控制在2.5%~2.6%之间较为合理,三次风开度为39%时NO_x排放质量浓度最低. 相似文献