基于专家控制器的空气预热器漏风控制系统

叙述了已应用于某发电厂回转式空气预热器漏风控制系统的工作原理,重点分析了造成空气预热器漏风的主要原因,提出了一种基于专家系统模式、利用计算机数据库技术及知识库相结合的规则方法来实现预热器的漏风控制方案．实际运行结果表明,该系统能够有效地降低预热器的漏风,使得机组总体漏风率下降10％,为机组的安全满负荷运行提供有力保证．     

新型漏风控制系统在1000MW超超临界火电机组中的应用

如今,对于锅炉燃烧控制的高效能运行、安全性能以及节能消耗的要求越来越高。在分析我国首台研发的1 000 MW超超临界火电机组空预器间隙系统控制结构的基础上,针对1 000 MW超超临界火电机组锅炉中,空气预热器存在的漏风问题,结合系统工作原理,构建新型漏风控制系统,提出有效的控制方法。基于PCL系统,确保改善1 000 MW超超临界火电机组空气预热器的漏风问题,真正实现运行稳定、系统性能可靠,确保1 000 MW超超临界火电机组的环保、高效、安全等性能。     

600 MW机组空预器漏风控制系统的优化改造

该文通过分析600MW机组空气预热器的漏风问题,针其对漏风从控制系统优化改造的角度提出了一种有效方法。实际应用效果证明该方法能够在保证机组稳定可靠运行的基础上,有效降低机组空预器的漏风量,提高了机组的运行经济性。这对我国600MW主力机组的安全高效运行提供了一定的借鉴意义。     

基于PLC的空气预热器间隙控制系统

分析回转式空气预热器的漏风原因,介绍基于PLC的密封间隙控制系统的组成、工作原理及软件的各项功能.实际应用结果表明该系统工作准确可靠,有效地降低了空气预热器的漏风率,为机组的安全满负荷运行提供有力保证.     

基于PLC的空气预热器间隙控制系统

分析回转式空气预热器的漏风原因，介绍基于PLC的密封间隙控制系统的组成、工作原理及软件的各项功能．实际应用结果表明该系统工作准确可靠，有效地降低了空气预热器的漏风率，为机组的安全满负荷运行提供有力保证．     

电厂烟风系统空气预热器漏风治理与节能效果

电厂烟风系统空气预热器漏风属于常见故障问题,漏风问题出现后会严重提升系统运行的电能消耗量。空气预热器漏风问题主要有两种:携带漏风和直接漏风。预热器漏风问题会严重影响设备运行质量和效率,还会导致设备零件的损坏,尤其会增加电厂运行能源消耗,因而需要利用有效的漏风治理措施对漏风问题进行治理。该文对其治理与节能效果进行分析。     

空气预热器漏风原因分析及安装控制措施

容克式空气预热器在当前大型火力发电机组中作为烟气热交换的设备被广泛采用。空预器热经济性指标的重要参考就是漏风率的大小。本文以某电厂1000MW机组空预器安装为例,就空预器漏风原因进行分析,并提出了在安装过程中所需要注意的环节和控制方法。     

火电机组回转式空预器漏风控制系统

对国产回转式空气预热器漏风进行了分析,并提出了回转式空气预热器漏风控制系统的设计思想和方案．     

回转式空气预热器改造技术的探讨

为解决电厂锅炉空气预热器漏风率过高的问题，提出了新的空气预热器改造方案，其技术关键是通过安装新的扇形板和轴向密封板，形成双密封；在转子轴的密封中增加迷宫密封等方法，使漏风率由30％下降到9％，保证了锅炉正常运行及运行的经济性。     

电站锅炉空气预热器漏风控制系统

电站锅炉空气预热器漏风控制系统是大型火力发电厂锅炉的配套自控设备。该系统的间隙检测与转换部分采用耐高温传感器 ,控制部分采用总线工业控制计算机和分布式专用计算机系统 ,能够在 40 0℃下对空气预热器的密封间隙进行非接触检测和闭环控制 ,减少漏风 ,提高锅炉出力 ,保证机组实现满负荷发电 ;传感器体积小 (外形尺寸为2 0 0 mm× 2 0 0 m m× 2 0 0 mm) ,便于安装 ,特别适用于老机组的技术改造 ;计算机系统采用工业一体化工作站 ,可同时对多个回路进行实时控制 ,具有打印、存贮、通讯等功能 ;使用温度≤ 40 0℃ ,测量范围≤ 1 0 mm,线…     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-