Operation experience with cast rotor blades made of Russian alloys in stationary gas turbines

The article presents the results of the analysis of operation of working blades made of cast nickel alloys applied in gas turbines for power. Russian alloys having equiaxial crystallization, i.e., TsNK-7, ChS-104, ZMI-3U, ChS-70U, ChS-88U, ZhS6K, and one foreign alloy IN738LC (for comparison) are considered.     

Estimating the influence of short-term overheatings on the structure and properties of the metal of blades made of IN 738 and IN 792 cast nickel alloys

Results from studies on analyzing the influence of overheatings with a duration of 1 h on the structure and properties of the metal of blades made of IN 738 and IN 792 cast nickel alloys are presented. Such overheatings may occur during operation of power-generating gas turbine units and cause emergency damage to them. Modern rotor blades and guide vanes have small dimensions and thin walls, due to which standard samples for determining the mechanical and heat-resistance properties cannot be cut out from them. The results of this work can be used for estimating the state of the metal of blades that have been in operation as to their microstructure.     

Estimating the repairability of blades used in gas pumping units

Results obtained from a study of the postoperation state of the blades (after they had been in operation for up to 56000 h) used in the high-pressure turbine of a GTK-25IR gas pumping unit made of ZMI-3U and In738 nickel alloys with protective coatings applied on the cuter surface of the blade and in its inner cavity are presented. It is shown that the blades can be repaired with taking into account structural and phase changes occurring in alloys and coatings. The boundary conditions regarding the possibility of carrying out repair and restoration works are determined depending on the time for which the blades have been in operation.     

Field experience with the use of forged first-stage rotor blades made of EP800 nickel alloy for the GTE-45 gas turbine

We present the results from an investigation of the structure, mechanical, and heat-resistant properties the metal of forged first-stage rotor blades of the GTE-45 gas turbine of NPO Turboatom after they had been in operation for a long time at the Yakutsk district power station. It is shown that blades made of this alloy may operate for as long as 60000 h provided that they have been manufactured with good quality. Criteria for the operational reliability of EP800 alloy are developed.     

The effectiveness of using controlled power turbines in gas-turbine units and regenerative-cycle and simple-cycle engines

Results from investigating the effectiveness of using a power turbine equipped with variable guide vanes are presented. Control ranges of turbines using these guide vanes are determined in the most typical operating modes of gas-turbine engines and units for thermal power-engineering purposes and gas transportation systems. Recommendations are formulated for the expediency of using the variable guide vanes of a power turbine to improve the operational efficiency of gas-turbine engines and units during the cold period of the year under partial-load conditions and in some other cases.     

PG9351(FA+e)型燃气轮机压气机的演化过程

系统地介绍了GE公司重型燃气轮机压气机的发展过程、F型压气机存在的问题以及目前我国PG9351(FA+e)型燃气轮机设备状况,并围绕压气机存在的问题进行了详细分析,介绍了该型燃气轮机所使用的压气机各级叶片的改进增强情况.     

大朝山电站225MW水轮机转轮卡门涡共振分析

分析了云南大朝山电站225MW水轮发电机组运行时发生卡门涡共振,产生金属蜂鸣声及叶片裂纹的原因,经分析处理并取得成功,为大型水轮机的安全运行提供了经验.图4表2     

Specific features relating to thermal fatigue rupture of the blade materials of gas turbine units

Results from thermocyclic tests of nickel- and cobalt-based alloys used to manufacture blades for modern gas turbines are presented.     

Prospective gas turbine and combined-cycle units for power engineering (a Review)

The modern state of technology for making gas turbines around the world and heat-recovery combined-cycle units constructed on their basis are considered. The progress achieved in this field by Siemens, Mitsubishi, General Electric, and Alstom is analyzed, and the objectives these companies set forth for themselves for the near and more distant future are discussed. The 375-MW gas turbine unit with an efficiency of 40% produced by Siemens, which is presently the largest one, is subjected to a detailed analysis. The main specific features of this turbine are that the gas turbine unit’s hot-path components have purely air cooling, due to which the installation has enhanced maneuverability. The single-shaft combined-cycle plant constructed on the basis of this turbine has a capacity of 570 MW and efficiency higher than 60%. Programs adopted by different companies for development of new-generation gas turbine units firing synthesis gas and fitted with low-emission combustion chambers and new cooling systems are considered. Concepts of rotor blades for new gas turbine units with improved thermal barrier coatings and composite blades different parts of which are made of materials selected in accordance with the conditions of their operation are discussed.     

Estimating the quality of coatings applied on the blades of a GTE-65 turbine

We present the results obtained from a comprehensive study of the plasma metalloceramic coating applied on the external surfaces and diffusion coating applied on the internal surfaces of rotor blades and guide vanes used in stages 1–3 of a GTE-65 gas turbine unit.     

A case of industrial safety appraisal for extension of service life of GTK-10-4 gas turbines used at gas transmission stations

It is shown that the extended life and enhanced operational reliability of parts and subassemblies of the most popular GTK-10-4 gas transmission plants are determined by the enhanced efficiency of the control over technical condition and operational safety of turbine plants in conformity with industrial safety requirements imposed on gas pipeline compressor stations. It has been established that the materials of parts and subassemblies of gas turbine plants with different, especially with maximal operating time, shall be exposed to NDT for the purpose of determining the actual mechanical characteristics of these materials with different operating time and calculating residual life. The analysis of damageability and operating conditions has helped to identify parts and subassemblies for repair or replacement with the highest frequency of unacceptable defects. These parts and subassemblies have been shown to include base members of the axial compressor (AC), a turbine housing, an axial compressor rotor, high- and low-pressure turbine (HPT and LPT) discs, a 12-part holder, the housing of the holder of HPT and LPT guiding blades, a sealed baffler, and working and guiding AC, LPT and HPT blades. The most typical operational defects have been enumerated and analyzed. It has been determined that the primary task of the industrial safety appraisal for extending the life of GTK-10-4 with limit-exceeding operating time is to thoroughly examine HPT and LPT discs with more than 130,000 hours of operating time and establish by DT methods characteristics of materials for evaluation, taking account of their degradation, and residual life of critical turbine elements. In addition, it has been shown that the service life of HP turbine discs can be extended by replacing the disc material (EP-428 12% chromium steel) with a material with a higher linear expansion factor that somewhat exceeds the expansion factor of EI-893 nickel alloy used to melt out working blades.     

大型风电设备转轮叶片的制造工艺

介绍了风轮机转轮叶片的结构型式、翼型的优化和材料性能,以及大型风轮机叶片的制造工艺,包括外壳成型、添充纤维的制作、真空浸渍和烘烤固化,指出风轮机的设计制造必须经过模拟试验。     

灯泡贯流式水轮机水力损失分析

对一台灯泡贯流式水轮机进行了全流道各过流部件的流场分析,探讨了各段流道内的水力损失在总损失中占有的比重以及产生的原因.分析结果表明,由于灯泡贯流式水轮机引水室形式的特殊性,几乎不能在导叶进口前提供环量,因此与有蜗壳的水轮机相比,这类水轮机的各过流部件在水力损失方面有不同的表现.活动导叶不仅作为调节流量的部件之一,也是转轮进口环量的提供者,导叶形状及与转轮的协联都对水轮机总损失有较大影响.     

Concept of turbines for ultrasupercritical,supercritical, and subcritical steam conditions

The article describes the design features of condensing turbines for ultrasupercritical initial steam conditions (USSC) and large-capacity cogeneration turbines for super- and subcritical steam conditions having increased steam extractions for district heating purposes. For improving the efficiency and reliability indicators of USSC turbines, it is proposed to use forced cooling of the head high-temperature thermally stressed parts of the high- and intermediate-pressure rotors, reaction-type blades of the high-pressure cylinder (HPC) and at least the first stages of the intermediate-pressure cylinder (IPC), the double-wall HPC casing with narrow flanges of its horizontal joints, a rigid HPC rotor, an extended system of regenerative steam extractions without using extractions from the HPC flow path, and the low-pressure cylinder’s inner casing moving in accordance with the IPC thermal expansions. For cogeneration turbines, it is proposed to shift the upper district heating extraction (or its significant part) to the feedwater pump turbine, which will make it possible to improve the turbine plant efficiency and arrange both district heating extractions in the IPC. In addition, in the case of using a disengaging coupling or precision conical bolts in the coupling, this solution will make it possible to disconnect the LPC in shifting the turbine to operate in the cogeneration mode. The article points out the need to intensify turbine development efforts with the use of modern methods for improving their efficiency and reliability involving, in particular, the use of relatively short 3D blades, last stages fitted with longer rotor blades, evaporation techniques for removing moisture in the last-stage diaphragm, and LPC rotor blades with radial grooves on their leading edges.     

An experimental study of the characteristics of a Darrieus turbine for tidal power generation

The Darrieus turbine was initially developed for wind turbines. An example of its application to water turbines is found in the Darrieus turbine installed in a duct for low head power generation, but no example is known of its application in a natural water channel. The authors have developed a Darrieus turbine that is suitable for tidal current power generation with the aim of establishing tidal current power generation technology through demonstrations in test channels and oceans. The efficiency of tidal current power generation is influenced by the characteristics of the turbine. The characteristics of the Darrieus turbine are mainly affected by the solidity and the number of blades. The Darrieus turbine was tested in test channels to find the most suitable values for the rotor solidity and the number of blades. This paper describes and examines those test results. © 2000 Scripta Technica, Electr Eng Jpn, 132(3): 38–47, 2000     

贯流式机组桨叶与导叶全三维联合设计

为了充分反映水流经过导叶后的流态对桨叶入流的影响,本文建立了灯泡贯流式机组桨叶和导叶的全三维联合反问题计算模型。在包括桨叶和导叶的计算域中,求解联立的控制方程,同时设计得到了导叶和桨叶的空间叶型。采用联合设计和单独设计模型分别设计了一低水头贯流式机组的桨叶和导叶,并在设计工况下对其进行了全流道湍流数值模拟。性能预估结果表明,与单独设计相比,联合设计的桨叶进口边附近压力分布得到改善,导叶和桨叶段的联合损失减小,转轮效率提高。     

超临界压力汽轮机固体颗粒侵蚀的表面硬化处理技术

简要介绍汽轮机的固体颗粒侵蚀及其对机组安全性和经济性的危害，介绍国外为预防汽轮机通流部分的某些喷嘴和动叶固体颗粒侵蚀所采用的各种表面硬化处理技术，包括等离子喷涂和扩散渗层的现场运行经验，供我国发展高性能大容量超临界压力汽轮机及亚临界压力机组受到固体颗粒侵蚀损伤恢复其性能时参考。     

Corrosion longevity of gas turbine blades protective coatings

Results obtained from long-term studies conducted at the NPO Central Boiler-Turbine Institute on determining corrosion longevity of gas turbine blade protective coatings applied using different methods are presented. It is found how the base and alloying elements of coatings, the ceramic layer thickness, and the corrosion resistance level of undercoat alloy influence the longevity of coatings.     

间隙空化对贯流式水轮机压力脉动特性的影响

许多贯流式水电站机组振动严重、噪声大,部分电站难以正常运行.目前的贯流式水轮机稳定性研究多侧重于转速频率和涡带频率,对高倍转速频率压力脉动危害性及其成因关注较少.本文将空腔危害水力机械稳定性理论应用于灯泡贯流式水轮机间隙空化研究,采用理论分析和原、模型试验验证相结合的方法,论证分析了间隙空化和高倍转速频率压力脉动的联系...     

水轮机模式液力透平流道式导叶的优化

由于水轮机模式液力透平级间导叶水头损失占比高达40%,需要对液力透平级间导叶进行研究。在可选的级间导叶中,流道式导叶正反导叶连为一体,流道相对独立,是一种水力性能较好的级间导叶。本文基于水力原动机理论,将水流环量概念贯穿液力透平流道设计全过程,设计了与水轮机模式液力透平转轮相匹配的流道式级间导叶,并采用正交试验的优化算法,对水头影响较大的因素,包括导叶包角φ、正导叶出口角 、反导叶宽度 、流道外壁最大直径 ,各取4个水平进行正交试验方案的设计。通过CFD数值计算,分析各个方案的性能,找出了各因素对导叶性能的影响规律,在此基础上获得了效率较高的导叶模型,并研究了水力性能、叶片表面压力分布及叶片内部流动规律。研究表明：各个参数对效率的影响力中, 最大, 最小;对水头的影响力中, 最大,φ最小。优化后的模型在设计工况点效率提高了5.83%,应用水头提高了7.15%,级间导叶损失降低了1.16%,导叶表面压力过渡更加均匀,叶片内部水流流态更加平稳,满足液力透平对于高余压液体的能量回收要求。本研究可以为水轮机模式液力透平流道式导叶的选型和优化提供参考。