特征通流面积法在汽轮机故障诊断中的应用分析

在通流部分几何尺寸不发生改变的前提下,汽轮机级段特征通流面积保持不变,可以作为汽轮机通流部分故障诊断的依据。本文介绍了常用的相对内效率法在汽轮机故障诊断中的不足,以及特征通流面积法在故障诊断中的应用原理和方法。并通过火电机组实际案例验证了特征通流面积法在故障诊断中的可行性,该方法可满足大型机组通流故障诊断对时间性和准确性的要求,对汽轮机性能监测和故障判断具有重要意义。     

汽轮机通流部分故障诊断方法研究综述与展望

研究先进的汽轮机通流部分故障诊断方法,对提高汽轮机运行安全性以及经济性具有重要意义。在介绍国内外汽轮机通流部分故障诊断方法研究的发展现状基础上,对智能故障诊断方法进行了对比分析。最后提出了一种基于经验模态分解(EMD)的超超临界汽轮机组通流部分故障诊断方法。     

新型RBF网络在汽轮机通流部分故障诊断中的应用

应用免疫遗传系统的调节原理及递推最小二乘法建立了一种新型RBF网络模型,通过计算特征参数信息熵,可快速、准确地确定故障诊断的知识库。将该模型与知识库应用于汽轮机通流部分的故障诊断表明,该模型收敛速度快、精度高并有较好的泛化能力。采用该方法对某电厂1台300MW机组进行了实际诊断,判定为高压缸结垢和高压缸调节阀通道结垢,其结果完全满足汽轮机通流部分故障诊断的需要。     

基于特征通流面积的汽轮机通流部分结垢诊断

基于汽轮机特征通流面积(CFA)概念,给出了特征通流面积及其变化率的计算公式,并采用该公式对某亚临界300 MW机组大修前、后汽轮机部分级组的特征通流面积及其变化率进行了计算,确定该汽轮机中压缸通流部分发生结垢.该结果与实际情况相符,表明汽轮机特征通流面积可以作为汽轮机通流部分故障诊断的依据.     

概率分布干涉模型在汽轮机故障诊断中的应用

本文提出了概率分布的干涉模型应用于汽轮机现场故障诊断的方法，以便准确识别故障．文中给出了该方法在汽轮机轴向碰摩故障和汽轮机断叶片故障诊断中的应用实例．     

汽轮机通流部分故障的特性分析及仿真计算

汽轮机通流部分故障后必然引起相关运行参数的变化，变化的大小和故障的程度有关。文章分析了汽轮机通流部分故障的机理，并定量分析了叶片结垢或腐蚀程度与相应段压力变化量之间的关系，给出了仿真计算结果。     

浅析汽轮机通流部分改造及效果

汽轮机通流部分是工质在汽轮机本体中流动做功所经过的汽轮机部件的总称.汽轮机通流部件主要包括截流调节装置、汽轮机静叶栅和动叶片、汽封和轴封及其它辅助装置.汽轮机通流部分技术改造是提高机组效率、节能降耗的有效措施.文章介绍了自2009年以来某地区汽轮机组改造的技术特点、原则和内容,结合现场性能考核试验对改造效果进行了分析,...     

基于改进KNN算法的汽轮机通流故障诊断方法及应用

汽轮机的故障诊断对整个电厂的安全运行意义重大。根据热力参数建立计算模型可以及早地观测到性能退化趋势,预测设备故障类型。本文采用特征通流面积的方法建立汽轮机系统性能退化模型,模拟系统故障样本与测试样本,建立设备故障样本库。通过使用改进的KNN（K-nearest neighbor）算法,基于汽水系统热力参数变化规律,计算当前机组运行数据样本相对于设备故障样本的相似度,判定当前机组各设备已发生故障的概率。通过对某S109FA联合循环机组汽轮机研究结果表明,特征通流面积在不同工况下的计算误差均在5%以内,满足工程计算要求。相比于传统KNN算法,改进KNN算法通过样本评估近邻在决策过程中的权重,取得了比传统KNN算法更高的分类正确率。对测试样本故障诊断结果表明,改进KNN算法比传统KNN算法诊断准确率更高,对测试样本诊断准确率为100%,采用改进KNN算法汽轮机系统故障诊断具有可行性,与现场实际情况吻合。     

汽轮机通流部分间隙变化对相对内效率和功率的影响

针对发电机组运行中汽轮机普遍存在通流部分间隙偏大的现象,通过计算研究了汽轮机通流部分间隙变大对相对内效率和功率的影响程度。研究表明,汽轮机通流部分间隙变大引起漏汽损失增加,对汽轮机高压级相对内效率和功率的影响都较大。指出对汽轮机通流部分间隙实行状态监测的必要性,为汽轮机通流部分检修和节能提供依据。     

概率因果网络在汽轮机故障诊断中的应用

在分析了汽轮机振动故障特点的基础上,提出了用遗传算法进行汽轮机等旋转机械故障诊断问题,定义了遗传算法求解故障诊断问题的概率因果网络,给出了求解故障诊断的数学表达式和适合汽轮机等旋转机械的故障集、征兆集、因果强度和先验概率表。建立了汽轮机故障诊断模型指出表达式的最小值的集合对应于故障集和征兆集,该模型能有效地识别出汽轮机的多故障,弥补了专家系统和神经网络等诊断方法不能正确诊断多故障的不足。     

K-65-12.8 condensing steam turbine

A new condensing steam turbine K-65-12.8 is considered, which is the continuation of the development of the steam turbine family of 50–70 MW and the fresh steam pressure of 12.8 MPa, such as twocylinder T-50-12.8 and T-60/65-12.8 turbines. The turbine was developed using the modular design. The design and the main distinctive features of the turbine are described, such as a single two-housing cylinder with the steam flow loop; the extraction from the blading section for the regeneration, the inner needs, and heating; and the unification of some assemblies of serial turbines with shorter time of manufacture. The turbine uses the throttling steam distribution; steam from a boiler is supplied to a turbine through a separate valve block consisting of a central shut-off valve and two side control valves. The blading section of a turbine consists of 23 stages: the left flow contains ten stages installed in the inner housing and the right flow contains 13 stages with diaphragm placed in holders installed in the outer housing. The disks of the first 16 stages are forged together with a rotor, and the disks of the rest stages are mounted. Before the two last stages, the uncontrolled steam extraction is performed for the heating of a plant with the heat output of 38–75 GJ/h. Also, a turbine has five regenerative extraction points for feed water heating and the additional steam extraction to a collector for the inner needs with the consumption of up to 10 t/h. The feasibility parameters of a turbine plant are given. The main solutions for the heat flow diagram and the layout of a turbine plant are presented. The main principles and features of the microprocessor electro hydraulic control and protection system are formulated.     

汽轮机改造后启动过程中的振动处理

该文就一台 2 0 0MW机组汽轮机改造后通流部分出现的振动问题进行了分析 ,并提出了处理意见和解决办法。表 1 4     

汽轮机通流部分的内部清洗方法

介绍了汽轮机通流部分湿蒸汽内部清洗方法的特点,并对其操作要点及步骤进行了阐述。这种方法相对于开缸的机械清理方法,具有其独特的优点,并对延长大机组开缸检修周期具有重要意义。     

大功率中间再热汽轮发电机组运行性能模拟计算

该文提出一种汽轮机通流部分准三元流场计算与热力系统热平衡计算联立求解计算中间再热汽轮发电机组气动和热力性能的软件系统。计算实例表明了本软件包的工程实用性。图１表３参８     

300MW汽轮机辅机的节能改进工作

本文从节能角度介绍300MW汽轮机组给水泵驱动汽轮机低压喷嘴、给水泵机械密封、高低压加热器疏水系统、凝升泵叶轮切削、轴封抽汽系统及加热器等的故障分析和改进情况。     

汽包水位自动调节中主汽流量的一种计算方法

给水三冲量自动调节中,通常采用调节级压力与主汽流量的关系曲线来计算实际主汽流量。通过分析Alstom某600MW空冷汽轮机的结构,通常采用的流量计算方法并不适用;并对目前的三冲量调节中采用的主汽流量,提出了一种更适合的计算方法。     

汽轮机发电机组动静碰摩故障的诊断与处理

文章介绍了汽轮发电机组产生动静碰摩的原因,以及碰摩振动发生、发展的机理,总结了碰摩振动响应的频谱特征,给出了现场故障诊断要点。同时从理论、实验研究和现场振动故障诊断处理等方面,对近些年来国内外,特别是国内在这方面的主要研究成果与经验进行了简要总结与评述。通过对导致动静碰摩的各类原因分析,对防止碰摩及振动的措施作了一些有益的探讨。     

基于Labview的600MW汽轮机在线监测诊断系统

以600MW汽轮机为监测对象,研发了600MW汽轮机在线监测诊断系统。该系统不仅具有现有汽轮机监测系统的全部功能,而且还具有操作简单、使用方便、价格低廉等优点,可作为基于虚拟仪器的新一代汽轮机监测诊断系统。     

Substantiation of the cogeneration turbine unit selection for reconstruction of power units with a T-250/300-23.5 turbine

The selection of a cogeneration steam turbine unit (STU) for the reconstruction of power units with a T-250/300-23.5 turbine is substantiated by the example of power unit no. 9 at the cogeneration power station no. 22 (TETs-22) of Mosenergo Company. Series T-250 steam turbines have been developed for combined heat and power generation. A total of 31 turbines were manufactured. By the end of 2015, the total operation time of prototype power units with the T-250/300-23.5 turbine exceeded 290000 hours. Considering the expiry of the service life, the decision was made that the reconstruction of the power unit at st. no. 9 of TETs-22 should be the first priority. The main issues that arose in developing this project—the customer’s requirements and the request for the reconstruction, the view on certain problems of Ural Turbine Works (UTZ) as the manufacturer of the main power unit equipment, and the opinions of other project parties—are examined. The decisions were made with account taken of the experience in operation of all Series T-250 turbines and the results of long-term discussions of pressing problems at scientific and technical councils, meetings, and negotiations. For the new power unit, the following parameters have been set: a live steam pressure of 23.5 MPa and live steam/reheat temperature of 565/565°C. Considering that the boiler equipment will be upgraded, the live steam flow is increased up to 1030 t/h. The reconstruction activities involving the replacement of the existing turbine with a new one will yield a service life of 250000 hours for turbine parts exposed to a temperature of 450°C or higher and 200000 hours for pipeline components. Hence, the decision has been made to reuse the arrangement of the existing turbine: a four-cylinder turbine unit comprising a high-pressure cylinder (HPC), two intermediate pressure cylinders (IPC-1 & 2), and a low-pressure cylinder (LPC). The flow path in the new turbine will have active blading in LPC and IPC-1. The information is also presented on the use of the existing foundations, the fact that the overall dimensions of the turbine unit compartment are not changed, the selection of the new turbine type, and the solutions adopted on the basis of this information as to LPC blading, steam admission type, issues associated with thermal displacements, etc.     

Development of High-Powered Steam Turbines by OAO NPO Central Research and Design Institute for Boilers and Turbines

The article provides an overview of the developments by OAO NPO TsKTI aimed at improvement of components and assemblies of new-generation turbine plants for ultra-supercritical steam parameters to be installed at the power-generating facilities in service. The list of the assemblies under development includes cylinder shells, the cylinder’s flow paths and rotors, seals, bearings, and rotor cooling systems. The authors consider variants of the shafting–cylinder configurations for which advanced high-pressure and intermediate-pressure cylinders with reactive blading and low-pressure cylinders of conventional design and with counter-current steam flows are proposed and high-pressure rotors, which can increase the economic efficiency and reduce the overall turbine plant dimensions. Materials intended for the equipment components that operate at high temperatures and a steam cooling technique that allows the use of cheaper steel grades owing to the reduction in the metal’s working temperature are proposed. A new promising material for the bearing surfaces is described that enables the operation at higher unit pressures. The material was tested on a full-scale test bench at OAO NPO TsKTI and a turbine in operation. Ways of controlling the erosion of the blades in the moisture–steam turbine compartments by the steam heating of the hollow guide blades are considered. To ensure the dynamic stability of the shafting, shroud and diaphragm seals that prevent the development of the destabilizing circulatory forces of the steam flow were devised and trialed. Advanced instrumentation and software are proposed to monitor the condition of the blading and thermal stresses under transient conditions, to diagnose the vibration processes, and to archive the obtained data. Attention is paid to the normalization of the electromagnetic state of the plant in order to prevent the electrolytic erosion of the plant components. The instrumentation intended for monitoring the relevant electric parameters is described.