球式热风炉长寿结构探讨及改进实践

由于球式热风炉存在清球周期短,热风出口、燃烧口易于损坏等现象,本文分析了现象产生的原因,通过将球式热风炉的套筒燃烧器改为改进型顶燃式热风炉的多火孔陶瓷燃烧,较为彻底地杜绝了这些情况的发生,实现了球式热风炉的长寿而且热风温度提高50⁸0℃。     

高炉热风炉用高发射率涂料的节能效果及机理分析

为研究高发射率涂料在高炉热风炉蓄热室内的应用效果,应用数学模拟和工业试验对比的研究方法对节能效果进行了分析.结果表明:模拟结果接近工业应用数据,可以定量地说明涂料对热风炉传热过程的积极作用;应用高发射率涂料后,可使高炉热风炉热风温度升高25℃,烟气温度降低13℃.结合数学模拟和工业热诊断结果,对涂料在热风炉内使用的节能机理进行了分析.认为在格子砖表面涂覆高发射率涂料,在燃烧期会使蓄热体内烟气与格子砖辐射换热加强,格子砖表面温度增加,且使蓄热体蓄热量增加.模拟结果表明:烟气中CO2成分对提高辐射传热起重要作用;CO2体积分数平均每提高5%,则热风温度提高6～8℃.     

内燃式热风炉全周期操作优化数值模拟研究

以某钢厂内燃式热风炉为研究对象,采用热风炉整体三维稳态CFD模型与蓄热室格子砖单孔道二维非稳态CFD模型相结合的数值模拟方法,对热风炉内燃烧、流动和传热过程进行计算,预测送风温度,确定热风炉燃烧期的最佳操作条件。数值模拟结果表明,将热风炉整体三维稳态模型的计算结果作为蓄热室格子砖单孔道二维非稳态模型的入口边界条件,能够准确模拟热风炉在各操作时期的热状态。热风炉燃烧期的最佳操作条件是空气消耗系数在1.0～1.1范围内,进入蓄热室的烟气平均温度最高可达1 390℃,热风温度最高可达1 214℃。     

复合文氏管在小高炉上的应用

高炉炼铁实践证明,风温每提高100℃,产量可提高4～3％,焦比可降低4～3％。可见提高风温是降焦增铁的有效措施之一。提高风温的途径,除改进热风炉结构和改善热风炉操作外,对小高炉来说,如何促进高炉煤气净化也是提高风温的重要课题之一。 为了提高风温,满足石球式热风炉对高炉煤气质量的要求,在双鸭山炼铁厂的17米~3高炉设计中,采用了两级复合文氏管的精细除尘设备,已于1977年11月18日投产使用。使用情况表明,该除尘设备的除尘效果良好,每立方米净煤气含尘量降至15毫米以下,热风温度达1000～1100℃。     

高炉炉顶煤气显热回收可行性研究

我国高炉炉顶煤气温度较高。一般可达250℃,使用热矿时入炉时可达350～450℃。本文对利用高炉煤气湿热予热净煤气烧热风炉以提高热风温度的可行性进行了研究分析,其中包括: 1.换热器种类比较与选择; 2.换热器安装位置的确定; 3.试管换热器结构; 4.试管换热器寿命预测;     

大型高炉热风炉技术的比较分析

高炉热风炉是炼铁厂高炉重要的附属设备,随着高炉热风炉技术的不断改进和提高,我国高炉热风温度已经逐渐得到了提高。高炉热风炉于二十世纪五十年代在我国得到应用,当时以内燃式热风炉技术为主,之后逐渐引入并开发了外燃式热风炉和顶燃式热风炉,技术逐步得到了提高。大型高炉热风炉以外燃式热风炉和顶燃式热风炉为主,比较典型的有外燃式热风炉Didier、NSC和顶燃式热风炉,该文主要比较分析了三种典型热风炉的本体结构,并对外燃式热风炉和顶燃式热风炉的速度分布、格子砖表面温度分布、风炉流场进行比较分析。     

长豇豆隧道式热风干燥特性及品质变化

应用自制隧道式干燥实验台对95,℃漂烫2,min后的长豇豆进行热风干燥实验,分析了在不同热风温度、热风速度、料层厚度条件下豇豆的干燥特性及干产品品质.结果表明:长豇豆干燥过程中干燥第1阶段表现明显,热风温度对干燥速率及品质的影响最大;经漂烫后的长豇豆在热风温度60,℃、热风速度0.3,m/s、料层厚度6,mm条件下干燥时所得产品Vc含量最高.研究结果可为长豇豆隧道式热风干燥生产实践提供参考依据.     

顶燃式球式热风炉烧炉过程温度场建模

针对热风炉烧炉过程中蓄热体温度难以实时在线检测的难题,结合计算流体动力学以及传热学,建立顶燃式球式热风炉烧炉过程温度场分布模型。首先,在综合分析炉内的煤气燃烧反应、烟气湍流规律和蓄热体与烟气动态热量交换过程的基础上,建立热风炉的烟气流动模型和融合蓄热球自身热传导的局部非热平衡多孔介质模型;其次,根据实际现场检测的温度、流量和压力合理设定所建模型的定解条件;最后,采用有限体积法对模型进行求解,得到热风炉的温度场分布。研究结果表明:所建立的模型能够正确、有效地模拟热风炉烧炉过程的温度场分布,模型温度计算值与实测拱顶温度的平均相对误差低于1%,与实测废气温度的平均相对误差为2.6%。     

新型外燃旋流热风炉内流动与传热过程数值计算

阐明中小型高炉的风温由1000℃左右提高到1 250～1 300℃的主要措施是将煤气与空气双预热;提出应用高速烧嘴和新型外燃旋流热风炉来预热助燃空气,烧单一煤气可以实现高炉1 250～1300℃高风温.对炉内流动与传热过程进行的数值计算结果表明,在蓄热球床表面没有偏流,气流及温度分布均匀.在中试炉上测量的烟气温度分布与计算结果基本吻合.     

高温石球热风炉的设计与试验研究

本文叙述了1771年我国自行设计和建造的第一座高温固定床蓄热式石球热风炉。这座热风炉的出风温度达1550～1600℃,风温降为1.5℃/分,它满足了磁流体发电试验机组的需要。试验结果:炉子来流速度为0.65标米/秒,排烟温度为250℃,传热系数为12～20大卡/米~2·度·周期,燃气经床层的最大压降约1000毫米水柱。实践证明:该炉的设计是正确的,设计计算方法及所取数据也是适当的。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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