HK40蒸汽过热炉炉管运行安全性分析

对运行近６０００ｈ的ＨＫ４０蒸汽过热炉炉管进行了宏观检查，管径测量，超声波测量 厚，硬度测量，光学金相组合分析及危险点分析，发同Ｂ室炉管材料晶界有蠕变空洞，由此得出蠕变损伤是该炉管的主要损伤形式，计算得出Ｂ室炉管的平均剩余寿命。     

HK40蒸汽过热炉炉管运行安全性分析

对运行近６００００ｈ的ＨＫ４０蒸汽过热炉炉管进行了宏观检查、管径测量、超声波测厚、硬度测量、光学金相组织分析及危险点分析．发现Ｂ室炉管材料晶界有蠕变空洞，由此得出蠕变损伤是该炉管的主要损伤形式，计算得出Ｂ室炉管的平均剩余寿命．     

新旧HP.Nb炉管焊接后剩余寿命评价

制氢转化炉在石化行业中应用广泛,作为关键设备的转化炉炉管,由于服役温度高,一般采用离心铸造的HK40或HP.Nb高温合金.当制氢转化炉炉管发生局部失效时,采用局部更换炉管方法可延长整根炉管的使用寿命.文中分别采用微观组织分级法、基于硬度测量的寿命预测方法以及Larson-Miller参数法对新旧HP.Nb炉管焊接后的寿命进行综合评价,研究结果表明新旧炉管焊接后的剩余寿命约为4.5×104 h,蠕变断裂发生在旧母材处.     

甲醇装置用转化炉炉管Incoloy800H合金的焊接工艺研究

甲醇装置用转化炉炉管Incoloy800H合金焊接时,液态金属流动性差、焊缝金属熔深浅,易产生各种焊接缺陷;其焊接接头的力学性能和耐蚀性取决于能否正确选用焊接材料、严格控制焊接热输入量以及制定合理的焊接工艺。结合甲醇装置用转化炉炉管Incoloy800H的焊接特点,通过手工钨极氩弧焊、焊条电弧焊焊接工艺试验和产品的施焊,表明所选用的焊接方法、焊接材料及焊接工艺规范正确合理。     

焦化炉处理量上限理论分析

焦化炉是延迟焦化装置的核心单元设备，也是整个装置提高处理量的制约因素。对5座焦化炉进行了现场标定和管内外过程模拟，在控制炉管结焦速率的情况下，对单面辐射焦化炉的处理量上限进行了分析。结果表明，以现场操作工况下平均热强度和1984年设计规范中冷油流速上限为基准时，4座单面辐射焦化炉的单炉处理量可分别提高到600-650kt/a和700－800kt/a，而炉出口热转化率仍低于炉管内重油的最大可裂化度。如将炉出口热转化率限制在20％，分别以操作工况下炉管平均热强度和1984年设计规范中平均热强度上限为限制条件时，4座单面辐射焦化炉的单炉处理量可分别提高到680.8-796.8kt/a和764－1100kt/a。     

制氢转化炉炉管长期服役后损伤评价

针对已服役10 a的制氢转化炉炉管,分析了炉管沿轴线的损伤状况.结合剩余寿命,对炉管的损伤程度进行了分级,得到了整根炉管各部位的损伤级别以及沿炉管纵向的损伤分布.结果表明炉管的累积损伤具有局部性,下部高温段的焊缝损伤较母材严重.因此,对于达到服役寿命的炉管,通过损伤分析,可局部更换下部炉管.     

圆筒炉炉管反向膨胀风险评价与处理

加热炉炉管向上膨胀是加热炉的一大安全隐患,本文对圆筒炉炉管反向膨胀的现象从原因分析、风险评价和应对性措施等方面进行了认真的分析和恰当的处理,在不停炉的状态下消除了隐患,保证了安全生产。     

蒸汽发生器炉管壁减薄机理

从腐蚀理论和影响因素来解释了“蒸汽发生器炉管失效分析”一文中所揭示的现象,蒸汽发生器炉管减薄主要源于内表面腐蚀,炉管径向截面出现裂纹和次生裂纹,腐蚀表面有冲蚀和气蚀痕迹。介绍了蒸汽发生器炉管壁减薄机理,炉管壁在高温高压的工况下,金属与水汽接触产生汽水腐蚀,形成以氧化铁为主的腐蚀产物。炉管内液体在流动过程中地被加热,产生大量的蒸汽泡,蒸汽泡溃灭过程中造成氧化膜甚至母体金属破坏。与此同时,应力和活性阴离子对氧化膜的破坏造成孔蚀;氧的存在加剧了腐蚀作用。气蚀作用能使脱落的固体颗粒在水汽中形成固液汽三相流冲蚀作用,使材料被除去,母体金属与介质直接接触,周而复始的连续作用使管壁减薄。通过论述,以期对炉管减薄有更清晰的认识,从而对蒸汽发生器的使用起到一定的指导作用。     

GK-VI型裂解炉辐射段炉管弯曲原因及对策分析

齐鲁乙烯装置GK-VI型裂解炉在投用运行三年后,辐射段炉管均出现了严重弯曲的现象,本文从炉管周向温差、炉管热膨胀、炉底导向槽及高温蠕胀变形等四个方面对炉管弯曲的原因进行了分析,最后得出分析结论,并提出相应的解决措施.     

GK-Ⅵ型裂解炉辐射段炉管弯曲原因及对策分析

齐鲁乙烯装置GK-Ⅵ型裂解炉在投用运行三年后,辐射段炉管均出现了严重弯曲的现象,本文从炉管周向温差、炉管热膨胀、炉底导向槽及高温蠕胀变形等四个方面对炉管弯曲的原因进行了分析,最后得出分析结论,并提出相应的解决措施。     

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