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1.
Presently, when the structure of energy consumption by industrial enterprises is being changed, many type PT turbine units operate with limitations imposed on their operating conditions, while type R backpressure turbines are often shut down for a long time or even removed from operation. Thus, the problem of using steam previously intended for process needs combined with the loading of the main equipment and additional generation of power and heat becomes urgent for many power stations. Three main ways for solving this problem are examined in this paper. Potential alternatives for retrofitting of cogeneration power stations (TETS) with types PT and R turbines are discussed. Each alternative solves a specific problem brought about by the actual operating conditions of a turbine at a specific TETs. The results of retrofitting of PT-80-130 turbines with an increase in the throughput capacity of the intermediate pressure cylinder (IPC) and R-50-130 turbines with installation of an additional low-pressure cylinder (LPC) are presented. The experience in operation of the retrofitted R-50-130 turbine with an unconventional arrangement where an additional LPC is installed upstream the high-pressure cylinder (HPC) rather than between the generator and HPC is also described. The experience in the upgrading of TETs with installation of bottom steam turbines driven by steam from a process steam extraction that is not demanded for is presented. Depending on the conditions at a specific TETs, a bottom steam turbine can be installed on a new foundation or in the compartment of a dismounted turbine with the use of serviceable auxiliary and heat-exchange equipment. 相似文献
2.
A. E. Valamin A. Yu. Kultyshev T. L. Shibaev A. A. Gol’dberg Yu. A. Sakhnin M. Yu. Stepanov V. N. Bilan I. V. Kadkina 《Thermal Engineering》2016,63(11):765-770
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. 相似文献
3.
The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions. 相似文献
4.
V. V. Bozhko A. V. Gorin I. V. Zaitsev I. A. Kovalev I. A. Nosovitskii V. G. Orlik S. N. Lomagin V. P. Chernov 《Thermal Engineering》2017,64(3):176-183
At turbine starts with low steam flow rates in idle mode, the low-pressure rotor blades consume energy, causing the ventilation heating of the stages and creating higher depression in them than in the condenser. This leads to the return steam flows in the exhaust of the low-pressure cylinder (LPC), reducing the heat due to the moisture of starting steam damps and cooling injections. It is shown that, as a result of upgrading with the transition to fully milled shroud platforms of rotor blades, the depression in the stages decreases and their cooling efficiency is reduced due to the removal of an elastic turn of the rotor blades under the action of centrifugal forces and seal of them by periphery. Heating the rotor blades of the last stages exceeds the temperature threshold of soldering resistance of stellite plates (150°C), and their mass strips begin. The start-up circuit providing both the temperature retention of the last stages lower the soldering resistance threshold due to overwetting the steam damps up to saturation condition and the high degree of removal from the dump steam of excessive erosive-dangerous condensed moisture was proposed, applied, and tested at the operating power unit. The investment in the development and application of the new start-up circuit are compensated in the course of a year owing to guaranteed prevention of the strips of stellite plates that lengthens the service life of the rotor blades of the last stages as well as increase of the rotor blade efficiency due to the sharp decrease of erosive wear of the profiles and reduction of their surface roughness. This reduces the annual consumption of equivalent fuel by approximately 1000 t for every 100 MW of installed capacity. 相似文献
5.
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. 相似文献
6.
V. N. Goloshumova Yu. M. Brodov I. Yu. Klyainrok A. A. Smirnov 《Thermal Engineering》2012,59(12):935-943
The results obtained from investigations of combined-cycle power plants produced by the Ural Turbine Works aimed at achieving high maneuverability, reliability and longevity of cogeneration steam turbines taking into consideration the possibilities of modern automated process control systems are presented. The dynamic models for simulating the heating of a steam turbine cylinder??s parts with the use of limited computation capacities are developed. 相似文献
7.
We present the results from a 3D numerical calculation aimed at analyzing the thermal state of the steam-cooled segment of
the flow path of a double-flow intermediate-pressure cylinder used in a steam turbine for ultrasupercritical steam conditions.
It is shown that the circumferential nonuniformity of metal temperature on the end-face surfaces of disks and on the rotor
surface may be disregarded when the turbine runs at the nominal frequency of rotation. 相似文献
8.
The schematic design of a cogeneration steam turbine with the generator placed on the side of the high-pressure cylinder is proposed. It is shown that the use of this solution is most promising for turbines with a longitudinal layout (like a T-175/210-12.8 turbine). 相似文献
9.
10.
Yu. K. Petrenya L. A. Khomenok I. I. Pichugin O. A. Vladimirskii V. M. Lyapunov A. S. Lisyanskii Yu. Ya. Kachuriner T. A. Ignat’eva S. A. Ivanov 《Thermal Engineering》2008,55(1):39-44
The systems for forced steam cooling of the high-pressure rotor and stator and the intermediate-pressure rotor of a steam turbine for ultrasupercritical steam conditions developed at the Central Boiler-Turbine Institute Research and Production Association jointly with Leningrad Metal Works (a branch of OAO Silovye Mashiny) are considered. The results from calculations of the thermally stressed state of the cooled elements of the high- and intermediate-pressure cylinders have shown that the design solutions adopted for forced cooling of these elements are efficient and promising. 相似文献
11.
12.
A. E. Valamin A. Yu. Kultyshev A. A. Gol’dberg Yu. A. Sakhnin V. N. Bilan M. Yu. Stepanov E. N. Polyaeva M. V. Shekhter T. L. Shibaev 《Thermal Engineering》2016,63(11):771-776
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. 相似文献
13.
It is shown that considerable reserves for improving energy efficiency are available at the majority of Russian cogeneration stations, because the arrangements using which heat is supplied for the needs of water treatment plants are far from being optimal. New solutions are proposed that allow heat to be supplied to these loads in a more economically efficient manner with the use of low-potential regenerative extractions from cogeneration steam turbines, as well as technologies for improving the efficiency of combined-cycle plants the exhaust gases from which are discharged into a boiler. 相似文献
14.
During the operation of steam turbines under transient conditions, due to different thermal expansion of the stator and rotor parts in the radial and axial directions, the clearances fixed in the course of assembling the seals of the flow path change, which causes rubbing in the seals and the wear of the latter. This inevitably increases the leakages through the seals. A particularly large difference in the relative axial and radial displacements of the rotor and stator parts is observed during the turbine start-ups when the difference in their temperature expansion is maximal. Upon the turbine stops, the turbine shafting runs down freely, as a rule, passing through all critical speeds at which the amplitude of the shafting oscillations reach their peak values, which also leads to seizures in the seals and their wear and tear. The seizures in the seals may also be a consequence of the eccentricity between the rotor and stator caused by the thermal strain of the stator, incorrect choice of the clearances, floating-up of the rotor in the bearing, and many other factors. Recently, standard shroud labyrinth seals are being replaced in the steam turbines by seals with honeycomb stator inserts, the design of which allows the ridges to cut into the honeycomb surface without damaging the former, which allows fixing a radial clearance in the seals of 0.5 mm. On the honeycomb surface where the ridges touch it, grooves are cut through. The wear of the shroud seals reduces the efficiency of the steam turbines during the operation to the greatest degree. However, by the present there have been no exact quantitative data available on the change in the leakage through the worn-out honeycomb seals. The paper presents the results of comparative experimental studies on the flow and power characteristics of seal models with smooth and honeycomb stator parts for various degrees of their wear. The studies showed that the leakages through the worn-out stator parts of the honeycomb seals increase approximately 1.7 times slower than under the similar wear of the ridges of conventional straight-through seals with smooth stator parts. However, this gain in efficiency achieved by replacing the standard smooth-wall seals with the honeycomb seals must be necessarily correlated with the measurement data on the nonconservative shroud forces in conventional axial-radial seals with smooth stator surfaces with a radial clearance of 4 mm, which is almost seven times lower than that in the honeycomb seals with a radial clearance of 0.5 mm. From the results obtained in the work, it follows that the installation of honeycomb shroud seals instead of traditional ridge seals in the high-pressure cylinders (HPCs) of the steam turbines for subcritical steam parameters with high-vibration-resistance rotors that have a sufficient margin of resistance to self-oscillations is undoubtedly advisable from the point of view of increasing the economic efficiency of the turbines. However, the use of honeycomb shroud seals with reduced radial clearances in the HPC parts of the steam turbines for supercritical steam parameters requires special cautiousness, since it is in the area of small clearances that the maximum nonconservative shroud forces capable of causing auto-oscillations of the shafting are observed and these forces are maximal precisely at high pressures. 相似文献
15.
The current state and ways for improving the effectiveness of steam turbine units at nuclear power stations (NPS) are examined. The specifics of NPS turbines is described. The comparison of NPS steam turbine performance with the performance of steam turbines at thermal power stations (TPS) demonstrates that power units of NPSs are much poorer in effectiveness due to relatively low steam conditions at the inlet and the presence of wet steam already in the first stages of turbines. A decrease in the relative internal efficiency of NPS turbines results from the enhanced negative effect of wetness in the expansion process: in modern NPS turbines, more than two-thirds of the heat drop is spent in the two-phase region, while less than one fourth in TPS turbines. It is demonstrated that the effectiveness of NPS steam turbine units can be increased drastically in the future only through a considerable rise in the turbine inlet steam conditions. This can be achieved by using a heat carrier at supercritical conditions in the NPS reactor. The dependence of the effectiveness of NPS modern turbines on the turbine inlet steam conditions in the applicable pressure ranges of the saturated steam and vacuum in the condenser, as well as on the turbine exhaust area, is examined. For a 1000 MW turbine, increasing the inlet pressure from 6.0 to 8.0 MPa raises the turbine power and efficiency by 3.5%. At a condensing turbine outlet pressure ranging from 2.5 to 7.5 kPa and a constant velocity downstream of the last stage, the turbine power and efficiency can be increased by 7%. The importance of the exhaust area for the turbine effectiveness is revealed. Alternative designs of the flowpath in a low-pressure cylinder are analyzed. A unique configuration of a steam turbine unit with two-stage moisture separation is proposed. The comparison of high-speed turbines with low-speed ones was performed. It is demonstrated that the efficiency of the examined turbines is nearly the same within the accuracy of design calculations and the test results, and it is slightly higher for low-speed turbines due to lower losses with outlet velocity. 相似文献
16.
一种基于有限体积法计算汽轮机汽缸轴向膨胀的新方法 总被引:4,自引:2,他引:4
汽缸与转子轴向相对膨胀是影响汽轮机启动速度及机组运行安全的重要因素之一,目前对汽缸膨胀的计算与模拟尚不能用于电厂机组运行的实时监测。该文在圆筒壁非稳态导热的基础上,给出了圆筒壁温度分布的解析解,提出有限体积法计算汽缸轴向膨胀。定义了体积膨胀特征温度,将汽缸沿轴向分成若干段,每段简化成圆筒壁,在此基础上,计算有限体积的膨胀特征温度,分别计算各段的膨胀量,然后累加。对理论模型进行了有限元验证,计算结果与有限元结果误差较小,满足工程计算的需要。通过该计算方法,结合已有转子膨胀计算方法可以实现汽缸轴向胀差的实时监测。 相似文献
17.
《IEEJ Transactions on Electrical and Electronic Engineering》2017,12(1):38-44
The structure of the modern wind turbine is becoming larger and more complex, with the wind rotor exceeding hundreds of meters in diameter. The blade shear force is also becoming increasingly serious below the rated wind speed, which leads to structure fatigue loads and instability of the generator power. For improving the dynamic performance of large wind turbines, it was proposed that individual pitch control (IPC) method was operated below the rated wind speed. In this paper, we analyze the relationship between the aerodynamic characteristics of blades and the nonlinear time‐varying pitch control system based on wind shear and the tower shadow effect. The combination of IPC and torque control is used to optimize the control mode of the wind turbine. By fine‐tuning the pitch angle, the unbalanced force on the wind rotor was relieved to achieve the purpose of mitigating fatigue loads. Finally, our experimental results prove the validity of the proposed IPC method below the rated wind speed by showing that it can improve power quality and reduce fatigue loads of the key components without reducing the generator output power. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
18.
由于天津市迅猛发展的供热需求,天津军粮城发电有限公司需要对超高压、一次中间再热、三缸三排汽凝汽式汽轮机(7号、8号)进行供热改造。因为全国没有同类型机组的改造经验,需要对机组改造的可行性、安全性、经济性作全面的评价。改造方案为:汽轮机通流部分不变,在中、低压连通管上开孔抽汽,在连通管至双流程低压缸入口前加装蝶阀调整,热网疏水回收进主机热力系统。7号、8号机组供热改造完成后,全年可实现供热224万GJ,节标煤6.3万t,在采暖期可以减少SO2排放582.4t,CO2排放16.12万t,粉尘排放1030.4t。 相似文献
19.
L. L. Simoyu G. D. Barinberg E. I. Efros V. V. Ermolaev L. A. Zhuchenko A. I. Shklyar Yu. A. Sakhnin S. I. Modenov B. B. Kalinin 《Thermal Engineering》2007,54(4):286-291
The basic principles of modernization of the low-pressure cylinder flow path of T-185/220-12.8 turbines are presented. It is shown that its implementation allows substantial increase in economic efficiency and reliability of the turbine unit operation in the condensation and cogeneration modes. 相似文献
20.
国外汽轮机高效化与转子锻件材料的开发 总被引:4,自引:0,他引:4
为了改善电站的热效率,蒸汽参数趋向于更高的温度与更高的压力.简要概述日本火电汽轮机高效化、结构紧凑化的发展动向,以及先进技术国家超前奠定的超临界高中压转子、联合循环用HLP转子及超净化低压转子锻件关键制造技术的开发成果.图14表6参13 相似文献