汽轮机胀差过大的原因分析及改进措施

本文从胀差产生的原因,分析胀差变化规律,针对我厂汽轮机的实际情况,分启动和正常运行过程中,对汽轮机胀差采取的相应控制措施或注意事项,以及在实际生产中起到的作用。     

提高TSI系统胀差传感器指示精度的安装方法探讨

在说明汽轮机滑销系统及胀差概念的基础上,针对胀差传感器的安装提出了考虑初始位移量的一种安装方法。经过实践应用,此方法可以提高TSI系统涨差传感器指示精度,为汽轮机的安全运行提供了保证,为汽轮机TSI系统中胀差传感器的安装提供了一定的经验借鉴。     

300MW汽轮机胀差变化的原因分析与控制

胀差是影响汽轮机启动速度以及机组安全行驶的核心参数,对于火电机组较为典型的变工况下胀差的变化具有较强的现实意义。该文从胀差产生的原因以及计算公式进行分析,阐述了胀差的产生机理,并详细介绍300MW汽轮机在运行中、装置结构与系统初参数等方面影响胀差的因素,探究了减小胀差的方法并变工中胀差的控制要点,避免因为胀差过大带来的安全隐患。     

提高背压在控制胀差中的尝试

胀差是汽轮机运行中重要的监视参数之一，在试验的基础上，介绍了一种控制背压机组胀差的方法．     

TSI系统装置在天业电厂的应用试验报告

汽轮机安全监视系统是监测、保护汽轮发电机组安全运行的重要设备,为了保证机组安全启停和正常运行,需对汽轮机组的轴向位移、缸胀、差胀、转速、振动、偏心度等机械参数进行监视。在这些参数超过极限值(危急值)时,保护装置动作,关闭主汽门,实现紧急停机。     

汽轮机运行中胀差的分析和控制

汽轮机为发电厂当中的常用机械之一,其运转情况的好坏直接影响到了电量制造的效率.本次研究当中将针对某发电厂的汽轮机在运转过程当中产生的胀差现象进行研究,对其产生的原因进行分析,对有可能由此引发的危害提出解决措施与建议.     

汽轮机检测保护系统安装要点及示值异常的鉴别

汽轮机监测保护系统是火电机组最重要的保护系统.机组在安装调试阶段时,往往会出现TSI系统参数异常.正确的完成TSI系统的现场安装和调试,是保障TSI系统准确测量、正确动作的先决条件.系统带电后,所有测点的测量通道都应指示出正确的测量参数.随着机组进入油循环和盘车,轴系位置发生了改变,TSI系统的参数输出也因此会发生明显的变化.机组启动后,由于机组各自不同的特性、安装水平等,TSI系统会输出各种各样的参数指示.当机组带负荷运行后,正常情况下,轴位移、胀差、缸胀、轴振、偏心和瓦振的输出参数,会随机组负荷的变化呈缓慢变化趋势.分别在安装调试阶段、进油盘车阶段、启动阶段及正常带负荷运行阶段,对汽轮机监测保护系统的示值异常进行了分析和探讨.     

汽轮机启停过程中的轴胀数学模型

汽轮机启停过程中的轴胀数学模型胥建群，曹祖庆（东南大学动力工程系，南京２１００１８）在电站仿真系统中，汽轮机差胀模型是很重要的一部分，而差胀模型又离不开轴胀模型。以往用有限元计算的轴胀模型，精度虽然比较高，但模型复杂计算周期长。以致很难达到仿真实时性...     

新川监测系统在汽轮机中的应用

本文介绍了将日本新川监测系统应用到火电厂600MW燃煤机组汽轮机,作为汽轮机安全监测系统系统,对汽机的转速、轴承振动、轴向位移、高低压缸差胀、偏心、绝对膨胀进行时实监测,对汽轮机进行安全监视与保护。     

汽轮机加热装置的合理使用

本文针对我公司200MW汽轮机启动与停止过程中,汽缸、法兰、螺栓等部件的加热或冷却速度不同,使汽缸金属产生热应力、热变形;并结合多年工作经验,阐述加热装置的合理使用及注意事项,能够有效的控制部件金属温差和热应力、热变形,从而控制高压胀差,保证了汽轮机启动与停止时的安全性和经济性。     

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.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

Call for Papers

<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