Then the sealing steam is routed from the inlet side gland 2 towards the. Turbine gland seal steam system free download as word doc. Overlooked gland seal can be big trouble power services group. 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. Turbine gland seal steam control valves valve engineering. Steam turbine gland seal control system westinghouse. 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. The turbine glands are sealed with labyrinth packing when the exhaust steam is led to the vacuum condenser.
Gland steam sealing system for steam turbine ap nam. Leakage solid particle erosion moisture erosion steam path deposits. Describe the main components in turbine systems including lubricating oil systems, steam and water seal systems and hydraulic power units and discuss irregular operations within a system identify the locations of the turbine supervisory instrument and describe their functions describe the steam turbine control concepts. It also covers the related lube oil systems, instrumentation, control systems, and auxiliary equipment. The function of the gland steam condenser is to maintain a subatmospheric pressure at the outermost leakoff belt of the glands and thereby prevent the leakage of steam from the glands into the turbine hall, where it would condense on the walls and plant. Prior to supplying steam to the turbine, the steam supply pipelines have to be drained and heated up. You face the ongoing need to enhance reliability, avoid unplanned outages, reduce maintenance costs and improve unit responsiveness not possible with your legacy system. The gland sealing steam system provides lowpressure steam to the turbine gland. A control system is provided to modify the temperature of the auxiliary steam to be more compatible with the self sealing steam, so as to eliminate thermal shock to the turbine rotor. Simultaneously, gland steam system is started to prevent air inleakage. The gland sealing steam system provides lowpressure steam to the turbine gland in the final sets of labyrinth packing. Jul 23, 2017 gland steam sealing system for steam turbine ap nam. To prevent air from entering into the turbine casing, sealing steam is led to the turbine glands.
However, bending can cause impact between stationary and. The rate of the deterioration is influenced by the turbine design, the steam quality, and the way the turbine is operated. Pdf simulation of speed steam turbine control system. In case of turbines with cooling water preheating and lowpressure lp. 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. Gland steam sealing system for steam turbine youtube. For understanding the gland sealing system first we have to understand why it is required so there are two main reason. Turbine shaft glands are sealed with auxiliary steam supplied by an electro hydraulically controlled seal steam pressure control valve. Turbine sealing system gland sealing labyrinth seal turbine self sealing duration. Us4793141a gland sealing steam supply system for steam.
Water contamination of steam turbine lube oilshow to avoid it 53 in the writers opinion, the best way of coping with this problem is to install a dry gas purge at the bearing housing seals. Ger3705 ge steam turbine design philosophy and technology. The three areas covered in this guide are the main steam turbine, the steam seal system, and the lube oil system. Fire resisting fluid acknowledgements glossary bibliography biographical sketch summary steam turbines consist essentially of a casing to which stationary blades are fixed on the. Speed control system turbine gland seal the turbine glands. Wagner, general electric company, issued may 11, 1982. Schofield ge company schenectady, ny introduction the need to provide stateoftheart products for a diverse and everchanging market is the chal lenge facing steam turbinegenerator manufactur ers in the 90s. Steam turbine a steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work.
A high pressure steam turbine having a sealing gland where the turbine rotor penetrates the casing of the turbine. A steam turbine package is made up of several components systems including the following. Boiler supply steam is used until there is sufficient pressure in the cold reheat circuit to supply the gland sealing steam. Main root causes for performance deterioration are. Dec 18, 2015 place the gland sealing steam system in service. This assists the labyrinth packing in sealing the turbine to prevent the entrance of air from reducing or destroying the vacuum in the associated condenser. 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. Unlike some packing designs, guardian packing rings maintain a positive radial seal during shutdown, turning gear, startup, and unit operation. 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. Function and system layout the two functions of the turbine glands and seals are. Basically, it is possible to equip the gas turbine with two fuel systems, namely natural gas and fuel oil. I failed the gland sealing system test at my large steam turbine field engineering training, so ill have to go look at my manual to answer the rest of your questions. Guardian packing rings can be installed in the hp, ip, lp turbine sections along with all gland seal areas in any steam turbine.
Hydraulic control systems in gas and steam turbines. Thus for a gland with a given number of restrictions, there is an associated pressure ratio that produces the maximum leakage through the gland. Ovation turbine control replacements include speed and load control, rotor stress and automatic turbine startup and sequencing as well as complete mechanical and hydraulic. Find gland sealing system steam turbines related suppliers, manufacturers, products and specifications on globalspec a trusted source of gland sealing system steam turbines information. The tutorial is introduced by discussing the basics of steam turbine systems including the. These requirements include basic design, materials, fabrication, inspection testing, and preparation for shipment. A steam turbine gland seal control system for a steam turbine driving an electrical generator which supplies power to a load after main circuit breakers are closed, and in which the gland is self sealing by steam in the turbine after said closing, comprising. Labyrinth packing an overview sciencedirect topics. An industrial steam turbine experiences performance deterioration over time. Steam turbine gland seal control system westinghouse electric corp. Steam turbine blade and method for manufacturing same by akio sayano et al, kabushiki kaisha toshiba, issued december 17, 2009. A gland sealing steam supply system for steam turbines, adapted to supply steam to a gland portion of a steam turbine which is driven by highpressure steam and lowpressure steam introduced thereinto, comprising a highpressure steam pipe for use in supplying highpressure steam to said turbine, a highpressure steam extraction pipe branching from said highpressure steam pipe, a high. Describes the control system for a steam turbine in a modern power plant.
As turbine exhaust is connected to a condenser which is operated below atm pressure so there are chances of air ingres or va. 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. Gland steam must have appropriate temperature and pressure which must be controlled during startup. A steam turbine gland seal control system for a steam turbine driving. Turbine gland seal steam system turbine steam scribd. How does the steam turbine gland sealing system work.
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