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1.
燃烧过程排放的氮氧化物(NOX) 气体是危害很大、很难处理的大气污染物.降低燃烧过程中的NOX排放有两类方法:一是降低NOX的原始形成,第二类是还原已形成的NOX;在还原已形成的NOX 方法中,再燃烧(即部分燃烧后期喷入燃烧) 是当今世界前景看好的低NOX 控制技术,它是利用燃料分级形成还原性气氛迫使NOX分解来降低NOX 形成的燃烧方法.其中,天然气做为再燃烧料已成功用于商业,并在其它措施的基础上再降低NOX50% ~70% .叙述了以天然气做为再燃烧料的再燃烧原理和途径,重点论述了采用无限快反应速率模型,并假定模拟烟气为层流或湍流粘性系数为常数的湍流情况下,运用有限差分及多重网格方法,计算出了这一还原反应过程的浓度场,得到了较为合理的结果.  相似文献   

2.
燃烧过程排放的氮氧化物气体是危害很大,很难处理的大气污染物。降低燃烧过程中的NOx排放有两类方法:一是降低NOx的原始形成,第二类是还原已形成的NOx;在还原已形成的NOx方法中,再燃烧是当今世界前景看好的低NOx控制技术,它是利用燃料分级形成还原性所氛迫x的分解来降低NOx形成的燃烧方法。  相似文献   

3.
流化床煤燃烧N2O,SOx及NOx的消减   总被引:3,自引:0,他引:3  
在一台循环流化床实验台,研究了石灰石脱硫过程中N2O/SOx/NOx浓度的变化,并在空床上进行了再煤燃烧脱除N2O的实验,结果表明,石灰石脱硫全吏NOx少量增加,再燃烧法可以在不增加NOx的同时使N2O大大降低,再燃燃料的挥发含量越高,N2O的消减率越高;气体停留时间越长,N2O的分解率越高;低氧量对现燃烧法消减N2O有利。  相似文献   

4.
在一台循环流化床实验台上,研究了石灰石脱硫过程中N_2O/SO_x/NO_x浓度的变化,并在空床上进行了再燃烧法脱除N2O的实验,结果表明,石灰石脱硫会使NOx少量增加,再燃烧法可以在不增加NOx的同时使N_2O大大降低;再燃燃料的挥发分含量越高,N2O的消减率越高;气体停留时间越长,N2O的分解率越高;低氧量对再燃烧法消减N2O有利  相似文献   

5.
石油焦燃烧过程中NO_x和SO_2析出规律的研究   总被引:1,自引:0,他引:1  
在卧式加热炉和富氧条件下,对石油焦在燃烧过程中的NOx 和SO2 析出规律进行研究,发现石油焦的NOx 和SO2 析出受多种因素的影响:温度增加,NOx 的析出量增加;颗粒粒径增加,NOx 和SO2 的析出量减少;石灰石微量增加,NOx 的浓度降低,石灰石过量增加,NOx 的浓度反而升高,石灰石的增加使SO2 降低;NOx 的析出并不与N 的质量分数成正比,SO2 的析出与S的质量分数成正比.结合这些实验现象,从机理上对它们进行解析.  相似文献   

6.
在滴管炉中对12 种煤进行了热解实验和燃烧实验.研究了煤中的氮在热解过程中生成的中间产物NH3 和HCN 与煤种的关系,煤的成分以及中间产物NH3 和HCN 对煤燃烧中NOx 生成量的影响.并提出了用VrNfφ(HCN)/φ(NH3) 的值作为预测指数来预测不同煤种在燃烧中的NOx 生成量.  相似文献   

7.
通过对以扩散燃烧为主的非均质燃烧与以预混合燃烧为主的均质燃烧中燃烧温度,碳粒生成、NOx形成,以及它们之间关系的研究,发现非均质燃烧中的高温,低氧浓度区不仅产生了碳粒,而且不易迅速氧化碳粒,导致较长的高温时间促使大量的Nx生成,而均质燃烧则会同时降低碳粒与NOx生成。  相似文献   

8.
采用重量法研究了C2H4、O2和N2在5A沸石和碳分子筛上的吸附平衡和扩散动力学性质。结果表明,在5A沸石上,C2H4的平衡吸附量和扩散速率均比O2和N2的大;在炭分子筛上,C2H4的平衡吸附量比O2和N2的大,而扩散速率则远小于O2和N2。模拟变压吸附评价表明:C2H4-O2-N2混合组分(含02 6.8%,N2 3.0%)通过该炭分子筛时,O2和N2的穿透时间长,可获得合格的乙烯产品;该炭分子  相似文献   

9.
A2BO4型复合氧化物具有非完整结构,A,B及O位均有空位,本文以硝酸盐为原料,用柠檬酸络合法使B位中掺入了Li离子,制得的活性组分La2LixCu1-xO4(x≤0.1)在650℃活化2小时,对于CO氧化反应和NOx还原反应同时有较高的他化活性,CO和NOx的转化率分别高于90%和80%.  相似文献   

10.
在卧式加热炉和富氧条件下,对石油焦在燃烧过程中的NOx和SO2析出规律进行研究,发现石油焦的NOx和SO2析出受多种因素的影响,温度增加,NOx的析出量增加,颗粒粒径增加,NOx和SO2的析出量减少;石灰石微量增加,NOx的浓度降低,石灰过量增加,NOx的浓度反而升高,石灰石的增另使唤降低;NOx的析出并不与N的质量分数成正比,SO2的析出与SD的质量分数成正比,结合这些实验现象,从机理上对它们进  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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