Coalfired supercritical steam power plants typically operate with steam temperatures in the range of 600c. Determination of stress intensity factors in low pressure. Feb 21, 2009 this is a 214 mw steam turbine rotor which is unusual because it has the high pressure, intermediate pressure, and low pressure sections all on the same rotor. Purpose this manual can be used for preliminary selection, steam and cooling water planning for steam turbines in basic and detail engineering stages. A steam turbine rotor is a large component rotating at high speed. The monobloc or integral rotor, in which the wheels and shaft are formed from a singlepiece forging fig 1.
We are your fullservice turbinegenerator service provider. The test is known as hst heat stability test and is carried out pursuant to the methodology given by the respective standards, e. A steam turbine locomotive engine is a steam locomotive driven by a steam turbine. Regardless of age or design of steam turbines, there are industry best practices to help.
Turbine instruction manuals will include allowable hold speeds or avoidance zones. The first steam turbine rail locomotive was built in 1908 for the officine meccaniche miani silvestri grodona comi, milan, italy. A pinned root fixing arrangement for an axial flow steam turbine rotor disc, said arrangement comprising. Relative size and weights, affecting cost and transport. Earlier steam turbine generating units had an inherent grounding. Table 1 lists typical examples of burst accidents of steam turbine rotors experienced peviously in japan and foreign countries. Cracks were analysed at the root of the third blade row of lowpressure steam.
The material used depend on the maximum temperatures and pressures to which specific components will be exposed which, in turn, depends u. Pdf fracture analysis of a low pressure steam turbine blade. Pdf structural modification of a steam turbine blade. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users.
Taking into account that for fatigue damage the permissible. Damage assessment and refurbishment of steam turbine blade rotor attachment holes d g hattingh 1, m n james,1, 2, m newby 3, r scheepers 3 and p doubell 3 1 department of mechanical engineering nelson mandela metropolitan university, port elizabeth, south africa danie. The rotor has been featured in other videos attached to a 1200 rpm 6 pole motor. Ge gas turbine shell repaired in 1992 for sicamore cogen near bakersfield california. In lp turbine section, cracking on rotor due to scc has been most prevalent in firtree or. Damage assessment and refurbishment of steam turbine blade. In april 2009, the steam turbine was overhauled again. Inlet and exhaust steam conditions year when unit was placed initial service location and orientation of the cracks, including which rotor and which discs.
Multilevel approach to lifetime assessment of steam turbines. For various crack lengths at lp steam turbine disc stress intensity factors are. The analysis of the data allowed drawing some conclusions. Critical locations such as keyway and dovetail area experienced stress concentration leading to crack initiation. During turbine startup, extra care must be used to ensure that the case has been properly heated and expanded sufficiently to. The steam turbine rotors showed abnormal thermal and load sensitivity with the abnormal rotor response. Steam turbine rotor testing with compressed air youtube. Maximum crack depth, allowed outage duration, spare parts. This is a 214 mw steam turbine rotor which is unusual because it has the high pressure, intermediate pressure, and low pressure sections all on the.
The stress corrosion crack initiation factor calculated value r scci 0. In the mechanical design of a steam turbine rotor, the rotor dynamics analysis is carried out, using the simplified model of a rotor with complex geometry. Four different types of rotor construction have been used on large turbine generator units on the cegb system. Professor emeritus mechanical and aerospace engineering former director, rotor dynamics laboratory, univ. For a low pressure turbine blade with a length of 0. Dynamic analysis and field balancing of 100 mw utility gas turbine generators edgar j. High pressure steam turbine rotor forging section replacement due to severe creep damage robert e. Some examples are steam line warming, steam superheat requirements and rotor eccentricity.
Dynamic analysis and field balancing of 100 mw utility gas. Determine the length of the tube required to condense steam at a rate of 115 kgh. Defects and fracture strength of large rotor forgings for steam. Steam turbine rotor discs failure evaluation and repair. A high pressure hp steam turbine driver was directly coupled to a centrifugal.
The use of longer steam turbine laststage blades lsbs reduces the number of lowpressure casings and, thus, a turbine s total installed cost. Steam turbine blade a real steam turbine blade b modelled blade c meshed blade d applied force and boundary conditions table 1. The weld repair of 84 mw steam turbine rotor discs has been successfully undertaken. The rotor is turned by steam impinging against attached vanes or blades on which it exerts a force in the tangential direction. Stabilizing furnaces for steam turbine shafts and rotors e. The selection of the rotational speed of a turbine generator depends on a number of factors, as follows. A steam turbine consists of a rotor resting on bearings and enclosed in a cylindrical casing.
Its precise whereabouts can be identified by comparing vibrations on both sides of the rotor. The equipment for steam turbine rotor thermal stability testing has to be understood by this abbreviation. Steam turbine generator shaft grounding principles historically, the problems and solutions to electrostatic and magnetically induced voltages on the steam turbine generator shafts of the test utilitys steam electric stations have been a continuous one. Other than these examples, various configurations are adopted as a steam turbine rotor. Because of the complexity of crack growth behavior, it is difficult to estimate. In 1924 krupp built the steam turbine locomotive t18 001, operational in 1929, for deutsche reichsbahn. Steam turbine rotor design and rotor dynamics analysis. Determination of stress intensity factors in low pressure turbine. The crack was through the outer bolt flange and was approximately 800mm long and 75mm thick. Unit size, initial steam conditions and availability of designs. Steam turbine rotors are therefore exposed to increased temperatures and. Manufacturer of steam turbine parts steam turbine blade, steam turbine nozzle, steam turbine rotor and steam turbine diaphragm offered by sudha engineering works, hyderabad, telangana. Paper open access related content structural modification of.
Application of an advanced creepfatigue procedure for flexible. This paper presents a multilevel methodology for a steam turbine lifetime assessment based on the damage calculation. Turbine rotor blade root attachments alstom technology ltd. Above 600 rpm rotor relative vibrations should be monitored. The rotor behavior, confirmed high probability of the shaft crack presence on the steam turbine rotor. A 21 mw steam turbine can serve to illustrate this phenomenon. This manual does not for designing steam turbine and the related parts. In general, a steam turbine is a rotary heat engine that converts thermal energy contained in the steam to mechanical energy or to electrical energy. Steam turbine rotor vibration that results in premature failure of blades and other components is one of the most serious problems in power plant operations. What is steam turbine description and characteristics. Which materials are being used in the major components of. Furthermore, recent studies show that the crack size for creep crack initiation cci.
In the prior art wellknown methods of attaching the dovetail between the turbine blades and impellers of the turbine rotor for a steam turbine. Director of engineering mike jirinec welding engineer damian parham turbine repairs design engineer alstom power inc. In its simplest form, a steam turbine consist of a boiler steam generator, turbine, condenser, feed pump and a variety of auxiliary devices. Steam turbine parts steam turbine blade manufacturer from. These inspections define the location and size of detected flaws. One the threshold is exceeded, automatic trip of turbine takes place. An attention in this paper is focused on the stress analysis and the determination of fracture mechanics parameters in low pressure lp turbine rotor discs and on developing analytic expressions for stress intensity factors at the critical location of lp steam turbine disc. Turbine configuration reheat or nonreheat, condensing or noncondensing, single casing or multiple casings, etc. A typical large steam turbine power generation unit will have a thick case, on the order of 12 to 18. The crack propagating cycling bending stress and the time from and to a crack.
Is there any allowable limit of slenderness ratio for a steam. A dovetail for a steam turbine, comprising a rotating blade curved axial entry dovetail having a four hook profile and a rotor wheel dovetail slot sized to receive the blade dovetail, the blade dovetail and wheel dovetail slot each comprising a plurality of slanted crush surfaces, a plurality of noncontact surfaces, and a plurality of necks that each provide a. Steam turbine types steam turbine types based on blade geometry and energy conversion process are. Variable parameters for turbine blade analysis case length l thickness t 1 400 10 2 400 15 3 400 20 4 500 10 5 500 15 6 500 20 7 8 9 600 600 600 10 15 20 3. This invention relates to turbines, in particular to compounds of the type dovetail between the impeller rotor of a steam turbine and steam turbine blades. Dec 16, 2017 we are building a case for our new steam rotor. Modern, fully viscous 3d calculation software allows a reduction in the number of flows plus a significant increase in the design point efficiency and an extended operating range. There are a number of permissives that must be met prior to rolling a steam turbine off gear. Due to the mass of this case, it will expand and contract at a slower rate than the relatively thin hollow rotor. The real values of critical speeds should be measured at. Note rolling at optimal steam pressures and temperatures can greatly improve cycle time. Steam turbinegenerator overhaul and inspection guidelines. Fracture analysis of a low pressure steam turbine blade.
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