浅析循环流化床锅炉风机的经济运行

对循环流化床锅炉风机在正常运行中的不同调整方式,从概念、安全性和经济性三方面进行了比较、分析,并提出了正常运行中风机经济运行的调整原则和方法,指出了合理的风机运行调整方式对整个机组经济运行的重要性。     

石灰石湿磨机出力的调整

根据火电厂烟气脱硫系统的石灰石湿磨机的实际运行情况提出了其出力的定义,并对石灰石湿磨机系统运行存在问题及出力的调整进行了论述.根据石灰石湿磨机的调整试验和运行表明,影响湿磨机最主要的因素是其钢球的装载量、石灰石浆液旋流器压力,并对其它影响湿磨机运行及出力的因素进行了分析并提出其调整的方法和措施.这些调整方法和措施对保证湿磨机的正常运行和最大出力起到重要作用.     

燃煤锅炉减少 NOX 生成运行控制措施探讨

电厂环保指标的要求日益严格,需调整运行措施以进一步减少炉膛 NOX 的生成,从而更好地实现环保.为此,阐述了 NOX 的生成机理并根据某公司实际运行调整试验数据进一步量化了日常锅炉调整方式对 NOX 生成量的影响,使运行调整更有针对性。     

阳泉二电厂双流弱酸床的工艺调整和实践

对阳泉二电厂双流弱酸床的运行工况进行了分析和调整,并对今后的运行调整提出了建议。     

某300MW煤粉锅炉燃烧调整试验

主要介绍了锅炉燃烧调整试验的内容、方法和调整过程中的注意事项,并以徐塘发电有限公司6号锅炉燃烧调整试验为例,分析了运行氧量、二次风配风方式和燃尽风门开度对锅炉运行的影响.试验结果表明,通过调整运行氧量和配置二次风配风方式及燃尽风门开度,可有效实现机组运行过程中的节能减排.     

山西铝厂自备电站锅炉运行调整试验研究

通过对WGZ130／39－11型锅炉的风速调整,一、二、三次风的合理配置及制粉系统等方面的运行调整试验的研究,总结出该炉运行的技术特性,确定了燃烧系统最佳的运行方式,为机组的安全经济运行和运行人员的操作调整,提供了科学的依据。     

无油锅炉配双进双出钢球磨煤机的运行调整

介绍了200 MW机组等离子点火配双进双出钢球磨煤机锅炉及制粉系统概况,以及双进双出磨煤机结构、等离子燃烧器布置方式。对无油点火稳定燃烧方式,锅炉运行特点、制粉系统运行调整,运行中出现的问题及原因进行了分析。提出了锅炉负荷调整应采取容量风量调整燃烧器粉量、旁路风量调整一次风速的方式,杜绝燃烧器的缺角运行;运行中维持一次风机风量与制粉系统通风量的匹配,保证一次风母管压力稳定的调整措施。     

二次风配风方式对锅炉燃烧优化的影响

结合工作实际，分析了锅炉燃烧工况存在的问题，指出锅炉运行调整中二次风调整的重要性及需要注意的问题，得出了对运行调整具有指导意义的结论。     

循环流化床锅炉节能运行存在的问题及优化调整

神华神东电力有责任公司根据运行经验,提出影响该公司CFB锅炉节能运行的关键问题为锅炉运行风量大和排烟温度高。结合实例分析了这2个问题对锅炉的安全运行和锅炉热效率等方面的影响,通过给煤粒度调整、一二次风量调整、床温调整等相关试验对CFB锅炉运行进行优化,使锅炉连续运行时间延长至3 600～4 800 h、锅炉热效率提高0.5%～1%、锅炉风机总电流降低20～35 A,优化调整效果显著。     

南方电网高压直流系统功率自动调整试运行情况及分析

介绍了南方电网直流功率自动调整试运行的准备工作和实施过程。对试运行期间的异常进行统计与分析,比较自动与手动两种调整模式的运行效果,显示直流功率自动调整系统的优越性。试运行结果表明,南方电网高压直流系统功率自动调整系统具备了安全运行条件。     

高速异步电动机转轴的疲劳特性分析

基于Ansys多物理场仿真软件平台,对高速异步电动机的转轴进行疲劳特性分析,校核高速异步电动机转轴的疲劳强度和高速运行的可靠性,预测电机转轴的寿命;分析电磁力对转轴疲劳寿命的影响,判断疲劳特性的类型。对比分析作用于电机结构的电磁力波频率、幅值和电机转轴各阶模态的固有频率,校核电机转轴的强度。在转轴不会因电磁振动发生断裂的前提下,将电磁力等效为静应力分析转轴的疲劳特性,校核电机轴在电机寿命周期内是否会发生短周疲劳损坏;并采用凹圆角设计进一步提高转轴的结构可靠性,提高电机的转轴寿命。     

交联聚乙烯交联度对材料击穿强度的影响

为了研究XLPE材料交联度对其电气性能的影响,制备不同交联度的XLPE样本并对其进行电气击穿实验,分析在不同的交联度区间范围内样本击穿场强变化。利用温度-时间控制法制备六组不同交联度的XLPE样本;利用差式扫描量热仪测量得到样本结晶度;利用交流变压器测量得到样本的击穿强度。实验结果表明,随着交联度上升,样本击穿场强呈先上升后下降趋势。在交联度为0%～75%区间范围内,样本击穿场强增加2%。在交联度为75%～88%范围内,样本击穿场强增加21.2%。而在交联度为88%～92%范围内,样本击穿场强下降5.3%。分析认为,样本的击穿强度与样本交联度和材料均匀程度有关。当交联度较低时,样本的击穿强度主要由样本交联度决定,随着交联度上升,样本击穿强度增加。但由于此时局部材料结构较为不均匀,因此击穿强度增加幅度不大。而当交联度上升至75%时,材料形成较为密集、均匀的三维网状结构,导致样本击穿场强大幅上升。而当交联度继续增加时,此时样本结晶度下降幅度较大,局部材料结构变得不均匀,导致样本击穿强度下降。     

特高压电晕笼防护段的设计

为了克服特高压电晕笼设计中电晕笼两端部的电场畸变,确保电晕特性测试准确有效,需要增设一定长度的防护段。采用三维有限元方法精细计算了电晕笼内导线表面电场分布,分析了导线弧垂对防护段长度的影响并提出了新颖的电晕笼防护段设计方法。计算说明新型结构的防护段能有效平滑和抑制电晕笼端部附近导线表面电场的畸变,使电晕笼内导线表面电场更趋于一致,提高了电晕特性试验的准确性。     

最小曲率法与峰值检测相结合的纸张计数算法

为解决叠层纸张计数的难题,提出了一种最小曲率法与峰值检测相结合的叠层纸张计数算法。首先,从叠层纸张图像中沿垂直纸张方向依此逐行提取灰度剖面,经高斯滤波后计算其曲率值。接着寻找叠层纸张的中心点,由于纸张的灰度剖面图呈高斯形状,所以局部极小曲率点是纸张的中心位置点,并且曲率连续0的宽度为一张纸张的厚度。然后,利用相邻中心位置点之间的距离以及相应点的灰度信息对纸张中心点位置进行校正。最后,利用峰值检测对脊线结果进行计数。本文算法通过融合纸张灰度特征与相邻纸张距离能准确检测异常纸张。实验证明,对于厚度在0.05~0.2 mm的叠层纸张的计数误差都小于0.01%。     

A Study of the Absorption of Nitrogen Oxides from the Boiler Flue Gases

In the past decade, the number of unsolved ecological problems has been steadily increasing. Among the numerous causes of this situation, the exposure of the environment to industrial waste should be mentioned. For example, enterprises of the fuel and energy industry emit a significant amount of hazardous substances into the atmosphere. Flue gases formed in boiler-houses and at thermal power stations get through flue gas stacks into the upper atmosphere and pollute it. In this work, a method is proposed for adsorption treatment of the flue gases from boilers fired with associated petroleum gas. The chemical composition of the associated petroleum gas of Romashkino oil field, the Republic of Tatarstan, is presented and the practicality of its use is demonstrated. Nitrogen oxides contained in the boiler flue gases result from oxidation of molecular air nitrogen during combustion of the fuel. In order to reduce the adverse effect of hazardous substances on the environment, the flue gases are to be compulsorily cleansed of nitrogen oxides. The use of the sludge resulting from coagulation and liming of natural water during the chemical water treatment at Kazan CHPP-1 as a sorption material is proposed. The chemical composition and technical characteristics of the sludge are presented. The properties of the sludge were studied using a laboratory fixed-sorbent-bed setup. The sorption capacity and water-absorption of the sludge were determined and curves of the kinetic and isothermal dependences of the nitrogen oxide adsorption by the sludge were constructed. The change in the nitrogen- oxide sorption capacity of the sludge depending on the sludge particle size was established. The optimal characteristics of a batch-type fixed-bed absorber were calculated. The results of calculating the economic and ecological effects of introducing the adsorption treatment of flue gases to remove nitrogen oxides for the boiler-house of AO Karpov Chemical Plant are provided.     

Considering the summation of the effect of harmful substances during the calculation of the environmentally safe waste water discharge

This article presents the technique of assessing the maximum allowable (standard) discharge of waste waters with several harmful substances into a water reservoir. The technique makes it possible to take into account the summation of their effect provided that the limiting harmful indices are the same. The expressions for the determination of the discharge limit of waste waters have been derived from the conditions of admissibility of the effect of several harmful substances on the waters of a reservoir. Mathematical conditions of admissibility of the effect of wastewaters on a reservoir are given for the characteristic combinations of limiting harmful indices and hazard classes of several substances. The conditions of admissibility of effects are presented in the form of logical products of the sums of relative concentrations that should not exceed the value of 1. It is shown that the calculation of the process of wastewater dilution in a flowing water reservoir is possible only on the basis of a numerical method to assess the wastewater discharge limit. An example of the numerical calculation of the standard limit of industrial enterprise wastewater discharges that contain polysulfide oil, flocculant VPK-101, and fungicide captan is given to test this method. In addition to these three harmful substances, the water reservoir also contained a fourth substance, namely, Zellek-Super herbicide, above the waste discharge point. The summation of the harmful effect was taken into account for VPK-101, captan, and Zellek-Super. The reliability of the technique was tested by the calculation of concentrations of the four substances in the control point of the flowing reservoir during the estimated maximum allowable wastewater discharge. It is shown that the value of the maximum allowable discharge limit was almost two times higher for the example under consideration, taking into account that the effect of harmful substances was unidirectional, which provides a higher level of environmental safety for them.     

基于复杂网络的产品竞争网的特性研究

专业镇经济是珠三角经济的重要特征之一,本文对以同类和关联产品为纽带的专业镇经济,从复杂网络的角度进行了分析.在专业镇企业集群的产品竞争网构建方面,提出了一个新颖的竞争选择度模型.通过基于竞争选择度模型的专业镇产品竞争网的建模分析,可以发现珠三角专业镇的产品竞争网具有比较典型的无标度和小世界特征.经过对广东顺德地区2个国内比较著名的专业镇产品竞争网的实证分析,可以大致得出与产品竞争网理论推导相符合的结论.     

220kV GIS隔离开关触头烧坏故障分析与对策

探讨220kV振林变电站GIS隔离开关动触头对外壳内壁放电导致绝缘击穿的原因。对20546隔离开关故障相气室进行解体检查,并采用X光透射技术对站内其它同批次的220k V隔离开关动触头分闸位置进行检测。根据检测结果分析,20546隔离开关气室故障原因为隔离开关动触头分闸不到位,造成电场畸变,从而导致动触头绝缘击穿。对20546隔离开关驱动轴进行调整后,故障相动触头分闸不到位问题得到解决。针对该变电站隔离开关动触头分闸不到位问题提出了控制措施。     

Electrostatic Current Generator Having a Disk Electret as an Active Element

An electrostatic current generator having a disk electret as the active element is described. The electret consists of two oppositely polarized half-disks producing an electric field normal to the plane of the electret. The electret constitutes the rotor of the generator and is located between two pairs of conducting half-disks which constitute the stator of the generator. The field of the electret induces charges on each half-disk of the stator. The magnitude and polarity of these charges at any given time are determined by the angle formed at this particular time between the plane separating the two halves of the electret and the plane separating the half-disks of the stator. When the half-disks of the stator are appropriately connected through an external circuit, an ac current is produced. The order of magnitude of the peak value of the current is given by I ? ?e?S where ae is the effective surface charge density of the electret, S is the total area of the flat surfaces of the electret, and w is the angular velocity of rotation of the electret.     

避雷针迎面先导发展物理过程仿真研究

开展避雷针迎面先导起始及发展过程的仿真研究对建立正确的雷电屏蔽分析模型具有重要意义。基于长间隙放电的物理机制,建立了包括正极性电晕起始与流注发展、先导起始、先导–流注体系发展等物理过程的迎面先导发展物理过程仿真模型,并使用实验室和自然雷电条件下的迎面先导发展过程观测结果对其进行了验证,最后采用该模型对避雷针迎面先导特性进行了分析讨论。结果表明:该模型的计算结果与实验室条件下和一次自然雷电条件下获得的正极性迎面先导发展过程观测结果相吻合;迎面先导起始时刻随着雷电流幅值和避雷针高度的增加而提前;避雷针迎面先导的发展过程主要受雷电流幅值、避雷针高度影响,其发展速度随着下行先导的趋近而逐渐增加;由实验室条件下的正极性棒–板间隙放电获得的先导起始特性直接用于自然雷电中正极性迎面先导起始的计算,以及在迎面先导发展过程的计算中假设迎面先导发展速度与下行先导发展速度成一固定比例是不合适的。