Alternate governing systems are supplied when required for some operating conditions or when specified by the client. As you would be aware that gland sealing steam is provided in condensing turbines. The condensate is recovered and introduced into the system via the main condenser. Up to nearly 40% load lowpressure auxiliary steam is supplied to the sealing header to seal hpt, ipt, and lpt glands. Some of these cookies are essential to the operation of the site, while others help to improve your experience by providing insights into how the site is being used. Dec 03, 2015 the steam turbine gland steam seal system is designed to keep steam from leaking out of the turbine and to prevent air from leaking into the turbine.
Gland sealing steam supply system for steam turbines hitachi, ltd. A gland leakoff condenser must be included to condense the gland steam. Carbon packing a watersealed glands and labyrinth seals as used on the highpressure end of condensing turbines. Gland condensers vacuum systems steam jet ejectors. If you will increase the gland steam pressure the the vacuum available at the exhaust will decrease or pressure will increase which will decrease th. The gland sealing system is designed to supply steam to seal the turbine shaft glands at all operating conditions and to extract leakoff steam from the glands. Fits between the rotor wheels and is fastened into the casing. Shuttingdown theturbinelube oil system activity 12 to prevent damage to the turbine generator bearings due to loss oflubrica tion, the turning gear must be switcbed off before tbe. Gland steam spray set point 150c this site uses cookies. Gland sealing steam ce titre est suivi dun tableau contenant. Gland steam condenser posted in industrial professionals. Gland seal steam control opens up and gland steam header pressure starts increasing.
Overlooked gland seal can be big trouble power services. Epr final safety analysis report tier 2 revision 1 page 10. Under certain conditions the gland is sealed by an auxiliary steam supply, and under other conditions the gland is self sealed by turbine inlet steam. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Us4793141a gland sealing steam supply system for steam. Prior to supplying steam to the turbine, the steam supply pipelines have to be drained and heated up. A steam turbine should trip or shut down when normal operating speed is exceeded by 1015% when the steam pressure drop occurs only in the stationary steam passages, the turbine is known as. Guardian packing rings can be installed in the hp, ip, and lp turbine sections along with all gland seal areas in any steam turbine. Various concepts were and are still developed and proven to work in test rigs. Main turbine generator the main turbine is an 1800 rpm, tandem compound six flow, reheat steam turbine. May 24, 2007 the steam turbine has two glands, one at h. Exergy analysis of marine steam turbine labyrinth gland seals. It is an assembly which is used to prevent the leakage of steam, fluid or water between sliding or turning part of the machine elements. Rotor extended outside the casing at both side and rear side.
Small heat exchanger used to condense the steam that leaks past the first section of seals on the shaft of a steam turbine. Gland steam sealing system only impulse turbine have diaphragms. To sealing turbine before pulling condensate vacumn before start up, gland sealing steam is extracted from the live steam system or auxiliary steam systeam and decreased both pressure and temperature pressure. To remove uncondensed steam and air if at all existing continuously.
Gland steam condenser mystery cr4 discussion thread. About the presentation this presentation teaches the reader about the operation and importance of steam turbines in electricity generation. A gland sealing steam supply system according to claim 6, wherein said system further includes a gas turbine, and a waste heat recovey boiler used for recovering heat of a waste gas from said gas turbine and having a highpressure steam generating portion consisting of an economizer, a highpressure steam generator and a superheater, and a low. Overlooked gland seal can be big trouble power services group. Any literature on large condensing steam turbines should include information about the gland steam condenser system. As turbine exhaust is connected to a condenser which is operated below atm pressure so there are chances of air ingres or va. Our type p ejector is ideal for small turbines where flow quantities of steam and air from the shaft seal bleedoff are relatively low. Axial split casing overspeed trip system governing systems. Hp and lp turbines and onto the gland steam condenser. Turbine oil demulsibility can be compromised by excessive water contamination or. Gland sealing systemgss of a steam turbine the steam turbine inlet pressure will be in hundreds of bar but when the steam exit, the pressure drops to either. Steam turbine blades look a bit like propeller blades but are made from highperformance alloys because the steam flowing past is hot, at high pressure, and traveling fast. Turbine shaft glands are sealed with auxiliary steam supplied by an electro hydraulically controlled seal steam pressure control valve. Api standard 612 petroleum, petrochemical, and natural gas industries.
Diaphragms are circular plates made up of two semicircular halves. Lately, in one of our steam turbines we are experiencing loss of vacuum, which we have attributed to the gland steam condenser malfunction. A gland seal system can be as simple as a spray chamber, loop seal and a steam ejector or as complex as surface condensers, air blowers or vacuum pumps. Steam turbine advanced sealing system mda turbines. Measurements of the leakage through a high pressure steam. What happens if we supply a high gland seal pressure for. This is particularly true for steam turbines where some level of gland seal water leakage is inevitable. Gland steam sealing system for steam turbine youtube. Thus for a gland with a given number of restrictions, there is an associated pressure ratio that produces the maximum leakage through the gland. Let us divide the gland seal system into four portions, gland steam supply arrangement, glands, gland condenser and ejectors. Fire resisting fluid acknowledgements glossary bibliography biographical sketch summary steam turbines consist essentially of a casing to which stationary blades are fixed on the.
A gland seal system can be as simple as a spray chamber, loop seal and a steam ejector or as complex as. Gland sealing steam supply system for steam turbines. When casing pressure is higher than atmospheric the gland sealing steam passes outward toward the gland steam. Turbine glandsealing system gland sealing provided to turbine shaft. Aug 17, 2017 this work focuses on the measurement of leakages through high pressure steam turbine gland sealing. Lp turbine turbine system seal steam system the penultimate section of each gland is supplied with steam from gland steam header, which is maintained at a pressure of 1. The main steam system also supplies the steam seal system and the auxiliary steam system when other sources are not available. If condenser is inefficient, huge amount of uncondensed steam is let to ejector. Steam turbine fundamentals an introductory guide to the operation of modern steam turbines v. Gland type flexible metallic packing water packing carbon packing a watersealed glands and labyrinth seals as used on the highpressure end of condensing turbines. Turbine gland seals are provided to eliminate the possibility of leakage of steam from the turbine through the turbine glands under pressure and ingress of atmospheric air into the turbine under vacuum. All steam turbines have the same basic parts, though theres a lot of variation in how theyre arranged.
The large, turbine gland sealing systems are basically self sealing, in the sense at a load 40% hp steam coming out from the hpt side could be enough to seal the same on the lpt side. Rotors, bearings, sealing glands singledisc, tworow curtis impulsetype wheels, shouldered, keyed and shrunk to a large diameter 4140ht steel shaft, prevent wheel movement relative to the shaft throughout the. A high pressure steam turbine having a sealing gland where the turbine rotor penetrates the casing of the turbine. In case of turbines with cooling water preheating and lowpressure lp.
Ep0268423a2 gland sealing steam supply system for steam. Turbine gland seal vacuum systems ejectors are the most popular choice for gland seal vacuum systems for removing air and steam from steam turbine shaft seals. Auxiliary steam from turbine auxiliary steam system tas is supplied to the glands to seal them. The ability of the oil to shed water will have a direct impact on its longterm oxidative stability and equipment rust. While the leakage of steam causes a reduction in cycle efficiency, entry of cold air may cause thermal shock to hot turbine internals. When casing pressure is lower than atmospheric, external steam is supplied via a letdown valve and desuperheater. Shaft sealing in high output turbines is done with. Steam turbine gland seal control system westinghouse electric corp. Otherwise, hot gland sealing steam would leak into the tuibine,causing the stationary hog. Two of the more important methods of classifying a steam turbine are by the stationary steam passages and the. Gland steam must have appropriate temperature and pressure which must be controlled during startup. For understanding the gland sealing system first we have to understand why it is required so there are two main reason. A steam powered eductor draws a vacuum and expels the noncondensables that are drawn down with the steam to the gland condenser.
Steam turbine gland seal control system patent osti. Specifically, if the turbine exhausts into a vacuum system, it is necessary to inject sealing steam into the seals in order to keep the low pressure end of the turbine from drawing in atmospheric air. The lp turbine shaft seals, which are under vacuum, are supplied with sealing steam from this header to prevent ingress of air. The leakage steam from glands are taken to gland steam condenser thru piping and returned to condensate system. Designed to succeed in steam turbine applications the gts seal advantage conventional dry gas seals applied to steam turbine applications can fail prematurely due to clogging of grooved face patterns, thermal distortions, and hangup problems of dynamic secondary sealing elements. The steam turbine gland steam seal system is designed to keep steam from leaking out of the turbine and to prevent air from leaking into the turbine. How does the steam turbine gland sealing system work.
One of the best videos on the topic of sealing a steam turbine. Cumulative steam mass flow rate lost through both labyrinth seals of each turbine cylinder has a small share in steam mass flow rate which enters. Laboratory tests for steam and gas turbine oils mobil. Because it is exposed to high temperature steam, the. Introduction during the past 50 years the gland ring has become a standard method for sealing medium and large diameter shafts. The gland sealing steam system provides lowpressure steam to the turbine gland in the final sets of labyrinth packing. Condensate from the main condenser is usually the source of cooling water for the gland condenser and the main air ejectors. Jul 23, 2017 gland sealing steam system for steam turbine. This publication is concerned only with the special carbon gland rings for steam turbine applications and similar glands sealing hot or dry gases.
A gland sealing steam supply system for a steam turbine, comprising means for supplying. Simultaneously, gland steam system is started to prevent air in leakage. Grt steam turbines alstom pdf catalogs documentation. A gland sealing steam supply system according to claim 6, wherein said system further includes a gas turbine, and a waste heat recovery boiler used for recovering heat of a waste gas from said gas turbine and having a highpressure steam generating portion consisting of an economizer, a highpressure steam generator and a superheater, and a low. Causes and solutions steam turbine rotors bend during operation, but the bearing and supports are designed to keep the static and dynamic forces under control. This system also prevents air leakage into the low pressure turbine glands.
Shaft sealing of steam turbines general electric company. The gland condenser uses cooling water to condense this steam to water which is usually lost to sewer. Fire resisting fluid acknowledgements glossary bibliography biographical sketch summary steam turbines consist essentially of a casing to which stationary blades are fixed on the inside and a rotor carrying moving blades on the. As its the usual the acid production is coupled with power generation steam turbine driven generators. Dec 18, 2015 place the gland sealing steam system in service. Simultaneously, gland steam system is started to prevent air inleakage. Gland sealing technologies are frequently in focus of research and development activities.
Gland sealing system complete heat exchanger steam. These requirements include basic design, materials. Labyrinth packing an overview sciencedirect topics. A game changer for gland sealing in general purpose steam. Pdf trouble shooting in turbine journal bearing vibration. This might includes tap off from steam header, control valves and isolation valves with connected piping. Dear all i am working as a head engineer at a sulphuric acid plant. This standard specifies the minimum requirements for steam turbines for specialpurpose applications for use in the petroleum, petrochemical, and natural gas industries. Recent technologies for steam turbines fujielectric. To condense the steam that leaks out of turbine and the steam supplied to sealing system. In order to accommodate the range of temperatures experienced throughout the turbine, the system is usually divided into two parts.
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