The failure of a lp low pressure turbine blade of a 220 mw thermal power plant is presented. Common failures in gas turbine blades sciencedirect. Request pdf failure of gas turbine blades the firststage blades of a gas turbine had suffered a severe deterioration after around 10 500 h service. Examination of the left propulsion system after the accident revealed that there had been a structural failure in the turbine, or hot, section of the engine. The failure of a second stage blade in a gas turbine was investigated by metallurgical and mechanical examinations of the failed blade. Under both of these conditions, turbine blades of presentday designs are more likely to react to the effects of dynamic loading due to unsteady aerodynamics.
Jul 05, 20 following an investigation, siemens says two separate incidents in which a b53 rotor blade broke off were both caused by adhesive bonding failure. Gas generator is derived from the f404 turbofan aircraft engine. Failure analysis of a jet engine high pressure turbine blade. Failure analysis of a first stage high pressure turbine blade. Prediction of flutter of turbine blades in a transonic. The blade was made of martensitic stainless steel and the structure was tempered martensite. Wind turbine blade reliability not just an acadi bldemic problem glass fiber reinforced wind turbine blade local failure at a manufacturing delaminations in a lowcost composite structure flaw field failure of a wind turbine blade judith gap montana 2009.
A set of first stage stationary blade of gas turbine was prematurely replaced due to severe cracking after 5,000 hours in operation. The wind turbine consist in the present work has 146 m diameter, three bladed, upwind rotor and stallcontrol with variable speed operation. Failure analysis of gas turbine blade ijert journal. This can lead to crack initiation and consequential failure of the whole blade. The gas turbine blade geometry is created by using coordinates. In a number of cases, the structural degradation results in a significant change in the. Gas turbine repair technology ge power systems ger3957b 0401 2 table 3. As industrial gas turbine blades are larger in size, they are more difficult to manufacture than those for aircraft engines. Failure analysis of gas turbine blades in a gas turbine. The findings of this study, based on the operating conditions and the characteristics of failed turbine blade, suggest a corrosion fatiguerelated failure.
Abstract the objective of this paper is to illustrate the manner in which a number of experimental techniques have been used in an integrated ap. Gas turbine interview questions and answers x gas turbine troubleshooting tips power plant gas turbine troubleshooting the following information required for troubleshooting gedesign heavyduty gas turbine issues. Blade failure was observed on a backpressure steam turbine driving a centrifugal compressor after it was in service for more than one year. Almost all commercial electrical power on earth is generated with a turbine, driven either by wind, water, steam or burning gas. General electrics turbine troubles raise more red flags. Maximum elongations and temperatures are observed at the blade tip section and minimum elongation and temperature variations at the root of the blade. Introduction gas turbines are required to operate under conditions of. The results show that temperature has a significant effect on the overall turbine blades.
Blade reliability workshopblade reliability workshop. A turbine blade is the individual component which makes up the turbine section of a gas turbine or steam turbine. Riley, armour research foundation of illinois institute of technology, chicago, ill. First, the fracture surface of the troubled blade was investigated. This is an example where mechanical behavior and reliability of the gas turbine are linked to performance degradation. Occurrences of wear and crack were observed on gas turbine blades in this section. Failure analysis of a lowpressure turbine blade in a coal. Machining marks creates stress concentration so fatigue crack occur 8. Failures can occur even in the best run power plant.
Potential failure modes hot gas path components gas turbine component life diagram with key factors assembly turbine operation outage assembly turbine operation outage assembly repair workscope repair workscope stores stores. Impulse turbines change the direction of flow of a high velocity fluid or gas jet. Recent technologies for steam turbines fujielectric. Nov 25, 2010 a gas turbine abruptly tripped to a stop during its daily morning startup period. When a rotating blade fractures in a gas turbine engine, it becomes a highenergy missile that can do extensive impact damage to other blades in the same stage and downstream stages of the engine. For this reason, the aim of this research is to use an. Development of advanced materials and manufacturing. Catastrophic turbine failure at vermont wind farm raises.
Blade failure was observed on a backpressure steam turbine driving a centrifugal. He has 21 years of industry experience including gas turbine and compressor design, troubleshooting, and engine development. Sensors, builtin during the blade manufacturing, should be able to detect the location of damage in a blade and send a warning to an onshore surveillance center. Focusing on the turbine blades and its life, the current method to calculate its creep life is complex and consumes a lot of time. In conjunction with the wind turbine optimization, maintenance and repair summit.
The power turbine of the pgt16 gas turbine is identical to that of the pgt10 heavy duty, high efficiency gas turbine which has been in operation for more than half a million hours. Assessment of research needs for wind turbine rotor materials technology. Over the last 20 years, the power industry has experienced a shift in steam turbine st maintenance strategies driven by two compounding factors. Most failures are thus detected at the incipient stage and appropriate action taken to prevent service failure. Prof4 1,2,4department of mechanical engineering, bvc engineering college, odalarevu, andhra pradesh, india. For example, dirt in the compressor can find its way into the small cooling holes of the hot section blading, impair cooling, and result in blade distress. Pdf failure analysis of gas turbine blades in a gas. Carter has described types of common failures in gas turbine blades such as high temperature, creep, fatigue and corrosion damages 3. Cross college, december, 2005 summary condition monitoring assesses the operational health of gas turbine engines, in order to provide early warning of potential failure such that preventative maintenance action may be taken. Siemens reveals root cause of turbine blade breaks north. This coordinate are imported into solid works20 software from uiuc naca4412. A common failure mode for turbine machine is high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of.
Out of a total of 81 blades in the first row only one blade was broken at its root. In this operation, a gas turbine is taken apart, each blade is dismantled, its surface cleaned and a new coating applied. If a gas turbine failure involves the fractures of many blades, it is necessary to determine which blade failed first. When they happen, there is an inevitable tension between efforts to return a turbine to service as quickly as possible and carrying out a failure investigation. Marine gas turbine blade, failure analysis, super alloy, and mechanical analysis etc 1. Unfortunately, unless a person or property is damaged in a turbine failure, there is no obligation for the owner of an industrial wind turbine to report the incident. Thus, cases of rotor blade failures were discovered in a generating gas turbine plant after operation for to 6000 h. Properties unit inconel 718 titanium t6 youngs modulus mpa 2e5 1. Pgt25 aeroderivative gas turbines the pgt25 gas turbine consists of an lm2500 ge aeroderivative gas. These figures correspond to a share of gas turbines in the total capacity, which climbed from 20 % to more than 50 % in this period of time. Investigation of blade failure in a gas turbine springerlink. This paper presents failure analysis of a first stage gas turbine blade of 30 mw gas turbine.
There are three stages of gas turbine blade in hot gas path turbine section of power generation gas turbine. In a gas turbine engine, a single turbine section is made up of a disk or hub that holds many turbine blades. This chapter focuses on those parameters that pertain to the manufacturing process for rotor blades. Failure analysis of gas turbine blades semantic scholar. The blade a had fractured at a height of about 4 cm from the blade root platform fig 1a.
Prior to this accident, there were three blade failure accidents in the same plant during the last 10 years. Wet flexural fatigue behaviour of tidal turbine blade. The failure took place after 20 k h of service exposure in the temperature range 700850 c, with the rotating speed being in the range 15,00016,000 rpm. Turbine blades are subjected to very strenuous environments inside a gas turbine. Rama rao reactor engineering division bhabha atomic research centre a b s t r a c t this paper is on a feasibility study carried out on a steam turbine for developing an online technique for detecting turbine blade vibration. Nlr offers a multidisciplinary approach to evaluate the condition and assess the life by integration of the following disciplines.
Meherhomjis areas of interest are power augmentation, aerothermal analysis, gas turbine deterioration, blade failures, and vibration analysis. The investigation was started with a thorough visual inspection of the turbine and the blades surfaces, followed by the fractography of the fracture surfaces. Method in order to evaluate the fatigue life of a tidal turbine blade, a methodology is purposed as depicted in figure 1, consisting. Life of gas turbine components dedicated to innovation. Longterm gas turbine operation leads to the structural degradation of superalloy blades there is a change in a number, shape and size of. The failure was reported in two blades in the second stage of a turbine compressor of a gas turbine in the hot section.
Introduction gas turbines play a important role in the todays society, and as the demands for power increase, the power output and thermal efficiency of gas turbines must also increase. Failure investigation was conducted on damaged blades by nondestructive penetrant inspection, microstructure examination, chemical analysis, hardness mapping and fracture surface observation. In fact this is a misconception, and freedom from service failures is largely the result of stringent standards imposed during frequent inspections. The technical specifications of baseline wind turbine are shown in the table 1. Compressor blade found to have failed in progressive mode i. Annual blade failures estimated at around 3,800 windpower. Low cycle fatigue analysis of a last stage steam turbine blade. They face high temperatures, high stresses, and a potential environment of high vibration.
The turbine engine has been in service for about 73,500 hrs before the blade failure. Macromicrofractographic studies were carried out on the fracture surfaces. Such failure would result in the destruction of the turbine and it may have catastrophic consequences. Studies and investigations on failure of turbine blades are continuing since last five decades. Failure analysis of gas turbine rotor blades sciencedirect. Blade failure modes such as fatigue, environmental attack. Introduction in recent years, environmental measures such as for reducing co2 emissions have been implemented on a global scale. Corrosionfatigue failure of gasturbine blades in an oil. Several premature failures were occurred in the highpressure section of an industrial gas turbine compressor due to the fracture of titanium blade roots. Stress analysis of the blade showed that the maximum. Such blade failures were observed in aircraft, marine and stationary gas turbine plants. There is no pressure change of the fluid or gas in the turbine blades the moving blades, as in the case of a steam or gas turbine. Wind turbine rotor blades are failing at a rate of around 3,800 a year, 0.
Reprinted with permission from the january 2014 issue recent. Dec 19, 20 last month, naw reported about four ge blade breaks that occurred this year, all of which involved the companys 1. Deac3608go28308 national renewable energy laboratory 150 denver west parkway golden, co 80401 3032753000. What is failure on turbine blade turbine blades are subjected to very strenuous environment inside a gas turbine the phase high temperature high stresses and a potentially high vibration environment all three blades factors can lead to blades failures which can destroy the engines and turbine blades are carefully designed to resist those condition. As the whole turbine is repeatedly started up and shut down, the varying centrifugal force results in alternating stress inside the blade material. Details of turbine blade material the turbine blade is subjected to rotational speed of 10800 rpm and firing temperature of 6190c. To survive in this difficult environment, turbine blades often use exotic materials like. This paper presents the failure analysis made on hpt turbine blades of 100 mw gas turbine used in marine applications.
Demand for more efficient thermal power has also intensified than ever. In this work, the failure process of the compressor blades was investigated based on the experimental characterisation. The common failure mechanisms found in gas turbine blades are discussed and illustrated. Iccm17 life prediction of wind turbine blades kk jin final. An investigation on failure analysis of titanium gas. Krishnakanth 20 did the structural and thermal analysis of gas turbine rotor blade using solid95 element. Type of meshing used for gas turbine blade during analysis process in ansys16. Residents evacuated blade failure 2005 crystal rig, berwickshire 40m blade shattered. This paper provides a comprehensive practical treatment of the subject, taking into account the complex nature of blading problems, influence of the operating environment, design factors, and maintenance practices. The paper addresses the key elements that could have possibly lead to the failure of the turbine blade and highlights the importance of. All three of these factors can lead to blade failures, potentially destroying the engine, therefore turbine blades are carefully designed to resist these conditions.
Pdf degradation of gas turbine blades for a thermal. As can be seen from figure 1, the gas turbine capacity yearly sold rose from less than 10 gwp. Higher efficiency is also being required of steam turbines, which are a mature energy conversion. The failure of gas turbine blade is due to the combination of aforesaid failure mechanisms. An advanced life prediction method is presented for the wind turbine blade subjected to time varying loads. Oct, 2006 for the love of physics walter lewin may 16, 2011 duration. Gas turbine interview questions and answers power plant. Engineering and metallographic aspects of gas turbine engine. High pressure turbine blades with internal cooling 3.
The turbine blades are often the limiting component of gas turbines. This analysis is a journal paper published july 15th 2014. Failure analysis of a first stage in738 gas turbine blade tip. This paper presents details of observations, inspections carried out and root cause. These investigations focus on specific engine blade stages. This paper presents details of observations, inspections carried out and root cause analysis of the turbine blade failure. To minimise the likelihood of a repeat failure, it. Insitu and nonintrusive measurement technique for detection. The resulting impulse spins the turbine and leaves the fluid flow with diminished kinetic energy. A common failure mode for turbine machine is high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery. Information on the number and types of failures is sparse and poorly reported, and thus this vital data is not adequately incorporated into estimates of turbine longevity. There have been several studies in the literature investigating failures of gas turbine blades after an incident or accident by applying metallurgical 2,6,14,15, mechanical 14,16 or chemical analysis 17 or other analytical methods 3,4.
With blading problems accounting for as many as 42 percent of the failures in gas turbines allianz, 1 978 and with its severe effect on plant availability, there is a pressing need for a unified treatment of the causes, failure modes, and troubleshooting to assist plant engineers in tackling blade failure problems. A gas turbine abruptly tripped to a stop during its daily morning startup period. Two failed blades were broken from the root and from the airfoil. During defect investigation after stripping of engine, one blade of turbine rotor of i stage was found broken designated as blade a and other had a deep cut at the trailing edge designated as blade b as illustrated in fig. Study of failure analysis of gas turbine blade patil a. Exc to shut down the turbine along with three others as a precaution. Siemens was forced to curtail 700 turbines worldwide after a b53 failure. The investigations includes the visual observations, material composition analysis, scanning electron microscopy sem and energy dispersive spectroscopy eds. The blade material, verified as in738lc nickel superalloy, exhibited. The blades are responsible for extracting energy from the high temperature, high pressure gas produced by the combustor. Ge followers will be aware that its haclass gas turbine, the flagship product of ge power, had a failure that caused exelon nyse. With, on one hand, the prospect of coating failure leading to catastrophic blade loss, and on the other hand an extremely expensive maintenance process, it is no surprise that much research is dedicated to improving the. Structural testing of the blade reliability collaborative. High pressure temperature hpt turbine blade is the most important component of the gas turbine and failures in this turbine blade can have dramatic effect on the safety and performance of the gas turbine engine.
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