Us6516618b1 gasturbine engine with a bearing chamber. Study of failure analysis of gas turbine blade patil a. Failures simply cannot be tolerated because they impact much more than just business. Airflow was being measured with a langeturbo bmf series bellmouth inlet flowmeter. None of the components of the bearing has shown any discolouration, wear, or overheating marks. A reduction gearbox is normally required so that the engine may drive a load at lower speed e. Failure analysis of an intershaft bearing of an aero gas.
Present technology of rollingelement bearings ntrs nasa. Approval issue course 234 turbine and auxiliaries module 10 stressed that these consequences. A multiplicity of seals are used in gas turbines to restrict gas leakage, provide thrust balancing, maintain thermal gradients, meter cooling gas flow, and protect bearing sumps. Pdf investigation of thurst bearing high temperature in. Turbine thrust bearing and its function the thrust bearing consists of babbitt metal lined, stationary shoes that run against the rotor thrust runner. Ball bearings depend on the continuous presenceof a very thinmillionths of an inchfilm of lubricant between balls and races, and between the cage, bearing rings, i. Reliability analysis of gas turbine based on the failure. When a gas turbine bearing fails, it can take your entire plant with it. Table 1 shows the lube oil sample analysis data of gas turbine that depicts the formation of varnish and considered to be the moan cause for bearing overheating. Pdf failure analysis of gef9 gas turbine journal bearings. Failure analysis of a first stage in738 gas turbine blade. The oil within the system was badly burnt and filled with microscopic particles. That is, the failure was cyclic dependent and apparently of subsurface origin, occur.
Vibration diagnosis approach for industrial gas turbine and failure analysis. Oil systems the main shaft bearings in a small gas turbine engine run at very high speeds, for this reason lubrication is very important to ensure a reasonable life expectancy. Maintenance induced failures misalignment, incorrect installation, etc. Each failure mode presents differ ent requirements for component repair. Failure from excessive exhaust temperatures or hot shutdown of engine results in carbon buildup. Fundamentals of gas turbine engines introduction the gas turbine is an internal combustion engine that uses air as the working fluid. Industrial gas turbines are in operation around the world in many unfavorable environments.
Data on the distribution by size of generatordrive gas turbines insured by allendale. This paper presents the investigation of bearing failure in a compressor test rig which has been satisfactorily in operation. Pdf this paper presents a failure analysis of journal bearings used in gef9 gas turbines. The required cleanliness and sensitivity of this piece of equipment is comparable to that of a jet engine. Failure characterisation of ti6al4v gas turbine compressor. Thrust bearing failure the recycle gas compressor 15k1. Gas turbine repair technology ge power systems ger3957b 0401 2 table 3. It is recommended that you idle the engine for two to three minutes to cool the bearing system before shutting down. In addition to failures in turbine generators, bearing failures in other rotating equipment, including pumps, fans, and auxiliary gas turbines and motors, can also lead to plant outages. Hybrid levered thrust bearings 2 mb catalog daipeak peek lining bearing 2 mb catalog bearing assembly 2 mb product details.
Mosaddeghfar3 1department of materials engineering, isfahan university of technology, isfahan 84156, iran 2department of mechanical engineering, isfahan university of technology, isfahan 84156, iran. Teardown inspections followed by metallurgical investigations are carried out on the parts of the failed bearing. Thrust and journal bearings are a critical part of the turbine sections function. An engine failure in an aircraft has a much higher likelihood of jeopardizing human life than a gas turbine failure in most industrial settings. While all outages cant be eliminated, bearingrelated uncertainty can be mitigated through proactive planning with the right partner. Gas turbine lubricating oils are hazardous substances, avoid prolonged exposure to oil and wear protective gloves when handling oil. Claire soares, in gas turbines second edition, 2015. This paper presents failure analysis of a first stage gas turbine blade of 30 mw gas turbine. In this paper, the common failure modes of gas turbine are stated. The failure of a second stage blade in a gas turbine was investigated by metallurgical and mechanical examinations of the failed blade. Gas turbine failures are a major source of losses for the above insurance. J users manual for steady state and transient thermal.
Outline machine background vibration diagnostics machine operation field observations. Since a gas turbine has many sealing locations blade tips, interstage, mainshaft, etc. This module provides an overview of the purpose of bearings within a combined cycle system, as well as common terminology that applies to bearings. Note the manometer on the left monitoring pressure differential of the static and dynamic pressure taps in. Ceramic bearings for use in gas turbine engines lewis research center national aeronautics and space. Failure investigation the bearing failure was attributed to unit misalignment. 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. It is in this hot exhaust gas that the hotend bearing must sit, relying on extensive thermal management of the exhaust frame, lubrication oil and cooling air to maintain its position and that of the spinning rotor and to maintain its own integrity.
The engine extracts chemical energy from fuel and converts it to mechanical energy using the gaseous energy of the working fluid air to drive the engine and propeller, which, in turn, propel the airplane. In order to find weakest link and take correction action, fmea failure mode and effect analysis method has been applied. Gearbox, bearings and lubrication gas turbine world. Pdf investigation of thurst bearing high temperature in gas turbine. In addition to failures in turbine generators, bearing failures in other rotating equipment, including pumps, fans, and.
Analysis of bearing incidents in aircraft gas turbine mainshaft. This paper presents a failure analysis of journal bearings used in gef9 gas turbines. Feroz and others published investigation of thurst bearing high temperature in gas turbine find, read and cite all the research you need on researchgate. Matthew smillie, consultant engineer, quest integrity group. But severe flaking is observed on one side of the outer raceway. Home turbomachinery bearing systems powergenerating turbine bearings. Download the pdf version here a number of technological and scientific advances through the ages have helped us reach the standard of living we enjoy today. An alberta power producer had a bearing failure in the 100 megawatt natural gas peak unit turbine. Not surprisingly, aerospace maintenance practices are primarily driven by safety concerns. Survey of damage investigation of babbitted industrial bearings. One end of the shaft usually the compressorfan end uses a ball bearing usually a gothic arch or 4point configuration for radial and axial loads.
Failure analysis of gef9 gas turbine journal bearings. Detailed studies including visual examination, optical. Since they have significant damping fluid film journal bearings have a strong impact on the vibration characteristics of machinery. Journal bearing are used to take radial load of the shaft. Failure of an intershaft bearing in an aero gas turbine engine is investigated to determine its root cause. The gas turbines manufactured by ge energy have features that make them particularly suitable for pipeline compressor applications.
Investigation of thrust bearing high temperature in gas. Failures are typically i caused by restricted lubricant flow or excessive temperatures that degrade the lubricants properties. Nozzles that are candidates for repair undergo an initial metallurgical evaluation. It was also recommended to change lube oil of gas turbine due to high level of varnish contamination. Gas turbine bearings large gas turbines greater than 20 mw power output can be generally split between the aeroderivative models and the heavyduty or.
Maximum periods of operation between inspections and overhauls inplace, onsite inspection and maintenance use of local trade skills to disassemble, inspect, and reassemble gas turbine components in addition to maintenance of the basic gas turbine, other. Ge energys pipeline centrifugal compressor line complements its gas turbine line to optimize matching with the gas turbine driver resulting in perfectly integrated gas turbine compressor units. Some failure modes are not applicable to the prognostic architecture. Gas turbine engines have few moving parts, but the speed, at which the parts move, especially the rotor, requires constant lubrication to the bearings. Jp5845358b2 bearing support device for gas turbine. The tail bearing housing is the bearing chamber that supports the aft end of the lp rotor and contains the rear engine mounts. Detection of incipient bearing faults in gas turbine engines michael j. Case study on bearing failure free download as powerpoint presentation.
Detailed studies including visual examination, optical microscopy, scanning electron microscopy, xrd and oil analysis were performed to determine the root causes of failure. In this paper, an inflight gas turbine engine bearing prognostic and health. These can be catego rized under creep, thermal fatigue, oxidation, incipient melting and many forms of mechani cal damage. It can be used in several different modes in critical industries such as power generation, oil and gas, process plants. This invention relates to a gasturbine engine which is provided in the turbine interior with a bearing chamber for a turbine shaft, the bearing chamber being sealed by sealing elements, and with a scavenge line for the lubricating oil which is supplied to the bearing chamber, in particular is sprayed onto the bearings arranged therein.
Gearbox, bearings and lubrication typical small gas turbine reduction gear train small gas turbine engines spin at very high speed in the order of 25,00085,000 rpm. The failure of gas turbine blade is due to the combination of aforesaid failure mechanisms. Bearing failure investigation of turbomachinery test rig. Two pair of single row angular contact ball bearings, each pair in tandem, and the pairs in turn in back to back support the rotor shaft to meet compressor thrust and to provide moderate stiffness for smooth operation. Case study on bearing failure bearing mechanical turbine. The exhaust temperatures of most heavyduty gas turbines are generally between 500 c and 600 c, depending on the duty, fuel and efficiency of the turbine. When a gas turbine goes down, recovery can be an expensive, timeconsuming process. Gearbox misalignment on combustion gas turbine generator.
Failure characterisation of ti6al4v gas turbine compressor blades a. Each characteristic is described in detail and is shown in diagram form, accompanied by a color photograph. Shoes on both sides of the runner prevent movement in either axial direction. Exit guide vanes provide structural support of the bearing chamber and provide the pathways for oil, air, and instrumentation cables. When a gas turbine goes down, recovery can be an expensive, time.
The manual classified 16 sepa rate modes of bearing failure that are likely to occur in hydrody namic bearings on power plant rotating equipment table 1. Turbine end heat soak into the bearing housing results in oil carbonisation and corrosion of the bearing system. 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. Turbine generator bearing failures are a leading cause of power plant unavailability and can cause serious damage not only to bearing systems but also to rotors, stators, and nearby equipment. The investigations includes the visual observations, material composition analysis, scanning electron microscopy sem and energy dispersive spectroscopy eds. Ball bearings are more prone to failure when subjected to a combination of axial and radial loads, while roller bearings often fail due to damage due to roller slippage. In particular, the aircraft gasturbine engine has provided the impetus and driving. Three units experienced several times damage of the journal bearings on the. This is because it is often difficult to detect early stages of mechanical failure due to the masking of the vibration signatures by machine. Powergenerating turbine bearings for supporting rotating shafts of steam and gas turbines and power generators. Bearings journal bearings provide radial support for the rotating equipment and thrust bearings provide axial positioning for them.
Vibration diagnosis approach for industrial gas turbine. Manual of bearing failures and repair in power plant rotating. Wide wear pattern central darkened region on loaded pad of a gas turbine tilting pad. 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.
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