Steam turbinegenerator overhaul and inspection guidelines. Api 614 indicates an iso 32 turbine oil as the lubrication fluid. Thordon gm2401 is specially formulated to provide optimal wear resistance in abrasiveladen water conditions, routinely outwearing rubber bearings by a factor of two or more, yet, still exhibiting a significantly lower coefficient of friction compared to rubber. Lubrication system flushing may be either a displacement flush after a drain and fill or a highvelocity flush for initial turbine oil fills. Pdf oil bearing seals and aircraft cabin air contamination. Skf offers standard seals and custom engineered seal. Many turbine manufacturers recommend that oil should be changed when the rpvot value decreases to 25 percent of the new oil value. The higher viscosity of cool oil provides the increase in loadcarrying ability of the oil films needed during startup. These seals virtually eliminate leakage of the fluid or gas being handled in pumps or mixers. Additives are also frequently used in turbine oil to improve the film strength. Ge frame 5 6 7 9 spare parts capabilities antoni intl usa. The emulsion will separate quickly when the oil is new and clean.
Control and oil system lubrication system the oil supplied to the lubrication system as noted above passes through the oil cooler and thence to the main bearings, thrust bearings and turning gear. It often gets into the grooves and needs to be cleaned thoroughly before reassembly. The most suspected locations were the bearing 1 oil seal where accumulation and hardening of lube oil in the labyrinth seal may have had the chance to create hard coke deposits and the hp packing front labyrinth seal of the casing itself. Performance problems with group ii hydrocracked turbine. The primary factors that affect the maintenance planning process are shown in figure 1. Standard practice for design of gas turbine generator. Centrifugal compressor wet seals seal oil degassing and. This usually means protecting the steam turbine from overspeeds, water induction, loss of lube oil, corrosive steam, and sticking valves that could cause major damage to the turbine, and conducting internal inspections of the turbine. Pumps for oil supply, oil scavenge, seal pressurization and sump vent subsystems. A labyrinth seal for a gas turbine engine of the type having a high pressure compressor and high pressure turbine, an outer shaft interconnecting the high pressure compressor and turbine, a low pressure compressor and turbine, and an inner shaft interconnecting the low pressure compressor and turbine in which the shafts are concentric and are separated by the seal. The following features are employed in the turbine lube oilsystem for over pressure protection. What is a double seal and when to use one double seals. Turbine lubricants must control the rust and corrosion that could destroy precision surfaces, resist foaming and air entrainment, which could impair lubrication.
If the turbine does not have a labyrinth seal at the housing end, while the turbine is in the shop, the housing end may be bored to receive an aluminum seal. Varnish in turbine oils vgb powertech 6 l 20 autoren abstract varnish in turbine oils the appearance of varnish in turbine oil can lead to hydraulic malfunctions and to increased bearing temperatures. These two types of seals are very similar, differing only in thread size and the fact that the labyrinth seal is pressurized. Converting an oil bearing to water can help the operator to realize maintenance advantages from increasing accessibility of the shaft seal, environmental. Pressurisation of the system is controlled by the cutting in of the ac or dc seal oil pumps when oil overpressure relative to hydrogen pressure is too low. This catalog lists koyo oil seals and orings, including all items of the dimension series. These noncontact seals are essential ly reliable, but a significant loss in thermal efficiency is incurred because of seal leakage. Sour seal oil vapor recovery system 4 options flare purge 27 psi 65 psi 275 psi boiler. The ability to resist oxidation is the most important characteristic of turbine oils. Recovery system that separates gas from the exiting sealoil before routing to the degassing tank recovered gas sent to various outlets.
Integrally geared centrifugal compressors represent the latest technology, offering significant advantages over outdated. Generally, there is not a suitable boss for drilling over the seal and, usually either 1 cut a vertical hole with an end mill of such size to take a 18 in or 14 in nipple. Claire soares, in gas turbines second edition, 2015. Custommanufacture the seal from modular components to. Combined lube and seal one reservoir one turbine driven main oil pump mop and one motor driven auxiliary oil pump aop duplex coolers and filters. Rating is available when the video has been rented. Multistage vertical split centrifugal type b capacity. The lubricant pressures and flows may vary from compressor to compressor depending upon the speed and. The fuel system is a very key part of a combustion gas. Combustion gas turbine fuel pumps the modern combustion gas turbine is one of the most reliable machines in use and a workhorse of the electric power generating industry. The todays most common type of shaft end seal in the oil and gas industry is based on dgs technology. Centrifugal compressor wet seals seal oil degassing and control.
Radial flow, double chamber thrust type ac seal oil pump. Unit 1 cook nuclear plant turbine event status report. Leaks from the carbon box are adjacent to and directed at the labyrinths. The labyrinth seal is usually pressurized, but the helical seal depends solely on reverse threading to stop oil leakage. Jet engines bearings, seals and oil consumption haw hamburg. Jun 01, 2011 turbine lubricants must have excellent thermal and oxidation resistance at bearing oil temperatures that may approach 100oc in typical steam turbine or industrial heavyduty gas turbine and exceed 200oc in aeroderivative gas turbines. Any oil that makes it past the first part of the seal is thrown outwards due to the centrifugal force, forms vortices and therefore cannot pass the second part. A key factor with any installation is that the seals impede the progress of fluid. Another type of oil seal used on some of the later engines is the carbon seal.
Pdf a nonmetallic brush seal has been developed as an oil seal for use in turbomachinary. The bearing lubrication oil is contained by the oil labyrinth. Pdf on board aircraft, the common use of engine compressor, pressurised air to seal the oil bearing. As turbine exhaust is connected to a condenser which is operated below atm pressure so there are chances of air ingres or va. The elastomeric lip is energized by a spring and can be designed like any radial oil seal in. We routinely deliver packaged systems such as gas turbine fuel forwarding manifold assemblies, integrated lube and seal oil systems, dry gas seal and buffer gas seal packages, and steam turbine generator sets. May 14, 2017 seals types 2 hydraulic sealsrod seal and piston seal. Water is the most prevalent contamination in turbine lubrication systems.
Oil seals are used to prevent lubricants or other fluids from leaking. The owners operating mode and practices will determine how each factor is weighted. Carbonized lubricating oil had built up in the seal vacuum chamber and was coming in. Double seals provide a level of safetyzero emissions compliance not possible with single seals. Compressor turbine fuel seal oil circulation pump new fuel pressure seal oil degassing drum and demister sour seal oil trap less gas vented to atmosphere atmospheric seal oil degassing drum note. In large turbine engine ball bearings the inner ring is often split and pro vided with slots in the bearing center plane. The clipper oil seal is the anchor of the rotary seal. Parts for ge frame 5 6 7 9 engine gas turbine parts new aftermarket.
Performance and analysis of seals for inerted lubrication. Any evaporated oil fumes are evacuated from the space. Generator cooling and sealing system 2 linkedin slideshare. And keeping hot combustion gasses from oil lubricated shaft space. The air to oil seals were operated at pressure differentials to 300 psi 207 ncm and at speeds to 400 feet per second 122 msec. This triumphal procession goes back to the end of the 1980s of the last century.
Gas turbine engine bearings and seals flight mechanic. The consequences are unplanned downtimes and high costs. The aft sump is in the turbine rear frame where bearings no. Conventional bearing shaft seal systems used in gas turbine engines are often limited to a sliding velocity of about 100 ms, differential pressure of 3 bar, gas temperature of 300c and a seal. The mechanical face seal uses a liquid, such as oil, to lubricate, cool, and create a positive sealing action to the sealing components during normal operation.
Failure mode location different than previous service bulletin corrective action can cause high oil consumption hoc andor low oil pressure lop impacting all re220 apu installations action improved tube design status. How does the steam turbine gland sealing system work. To check the seal housing oil level, where used, lay the unit on its side with the fill plug at 12 oclock. The seal oil system prevents gas from leaking out of the compressor case. Any oil leaking past the lip seals of the oil labyrinth normally flows to the drain. In addition, these seals require a considerable axial length, and this has. Low flash point of turbine, compressor and seal oil.
Emulsion will form when the oil is mixed with water. Autodegradation can cause the creation of insoluble contaminants in low or noflow sections in a lubricating circuit, leading to varnish. Low flash point of turbine, compressor and seal oil could pose a safety risk contains a depleted antioxidant additive system and a large number of free radicals. Hydrosele total sealing systems for water turbine shafts.
Gearbox typical failure modes, detection and mitigation methods. A description of the types of high speed rotary shaft seals. The differential pressure p across the oil seal is the difference between the pressurized air entering the dry. I believe i understand how a labyrinth seal in a turbine engine works when a the engine is running. The same as piston rings in a reciprocating engine. Heavyduty gas turbine operating and maintenance considerations repairs, and downtime. Alube oil reliefvalve installed in the common discharge piping ofthe oil pumps. The drawing in figure 1 shows a cross section of the nondrive end nde of the turbine. 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.
These systems require auxiliary equipment such as pumps, regulators, filters, and so on for proper operation. Pump or approved equal, with above ground discharge and furnished with suitable driver and accessories to meet the requirements herein or as shown on the drawings. Gas turbine repair technology ge power systems ger3957b 0401 2 table 3. It is important to avoid oil leaks due to too low p through the oil seals. Gearbox typical failure modes, detection and mitigation. In addition, turbine oil dissipates heat and inhibits oxidation or corrosion, acts as a seal against outside contaminants, and flushes solid particles away from moving surfaces. National renewable energy laboratory national wind technology center. They can be onsite and running in a relatively short period providing quick additional power capability when needed. The differential pressure p across the oil seal is.
Centrifugal compressor wet seals high pressure seal oil circulates between rings around the compressor shaft oil absorbs the gas on the inboard side little gas leaks through the oil seal seal oil degassing typically vents methane to the atmosphere seal oil degassing may vent 40 to 200 scfminute. Gas turbines, solar turbines and compressor parts by. Double or dual mechanical seals are designed to ensure maximum sealing safety. Emissions regulation continually drives the automotive industry to innovate and develop. Re220gv and gx turbine oil tube leaks issue turbine oil pressure and scavenge tubes leaking. Inspection results unusually high misalignment was found among the turbine bearing supports offsets of up to 1 mm.
This protection is particularly important in those units where the main oil pump is apositive displacement type. Maintenance and overhaul of steam turbines wgp42 05. This is essential when pumping or mixing a dangerous or toxic substance. Alternative solution seal oil gas separation and recoveryuse simple process of separating seal oil and entrained gas with the gas routed to recovery andor use. Centrifugal compressor wet seals seal oil degassing.
A description of the types of high speed rotary shaft seals in gas. Development of an improved turbocharger dynamic seal matthew j purdeya,1 a cummins turbo technologies st andrews road, huddersfield, hd1 6ra abstract. Sealed air temperatures to 1200 f 922 k were employed. Turbine lube oil system flushing and initial filtration should be addressed when selecting turbine oil. For understanding the gland sealing system first we have to understand why it is required so there are two main reason. The oil is then transferred to the main tank where the physically dissolved gasses are removed under vacuum degassed oil. The product has a high specific heat in order to ensure good heat transfer from oil cooled engine parts. Function and system layout the two functions of the turbine glands and seals are. 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. Vibration monitoring identifies steam turbine seal rub. The oil that flows across the outboard ring mixes with the bearing lube oil and returns to a lube oil tank. Mobil jet oil ii is recommended for aircraft gas turbine engines of the turbojet, turbofan, turboprop, and turboshaft helicopter types in commercial and military service.
This system contained bearings from turbine engines a mm roller bearing and a 110mm duplex thrust bearing. Pdf nonmetallic brush seals for gas turbine bearings. Evidence of steam, oil or water leakage evidence of steam deposits proper position of all valves proper oil level condition of all control and trip linkages condition of instrumentation, conduit, wiring, insulation, etc. Turbine seal regulators the turbine seal regulators reduce seal steam pressure to 16 psia and supply steam to the turbine glands. Blade droop and seal reliability due to manufacturing tolerances and running clearances of machined components, there is a certain natural droop of the turbine blades. We fabricate piping assemblies and spool pieces in our iso 9001 certified, stateoftheart facility in belle vernon, pennsylvania, usa.
The use of dgss in the place of oil lubricated mechanical seals improves mechanical efficiency as the shear and friction power of the seal is significant reduced. This is a rule of thumb, and decisions made must be considered. Alternative solution sealoilgas separation and recoveryuse simple process of separating sealoil and entrained gas with the gas routed to recovery andor use. The low alarm warns of excessive oil consumption by the seal and also calls for backup pump start along with the various pressure switches and the highlevel alarm warns of primary pump turbine failure in a similar manner to the lube oil system. Each of the regulator valves is a pneumatically operated, diaphragmcontrolled globe valve. This paper will consider the stateoftheart of two general types of seals in a gas turbine. To keep the pressure contained within each rotor disk by sealing blade tips and rotor shaft. Main turbine lube oil system cleanup main generator seal oil system cleanup main condenser eddy current testing, repair and cleanup cleanup of all secondary system heat exchangers replace and setup turbine digital control system and turbine supervisory instruments. Development of an improved turbocharger dynamic seal. The contractor shall furnish a deep well oil lubricated lineshaft vertical turbine pump, manufactured by national. A fixed orifice bypassed with a valve giving a variable orifice effect, is. This study indicated that a 2i percent change in tsfc can be expected for a nominal change in seal.
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