Along with providing lubrication to the shaft bearings, the lubricant also lubricates the oil pump, and in some systems is used as a turbine control fluid in the hydraulic governing system. Approval issue course 234 turbine and auxiliaries module 10 stressed that these consequences. Turbine lubricants must control the rust and corrosion that could destroy precision surfaces, resist foaming and air entrainment, which could impair lubrication. Microturbine systems that provide both cooling and heating can be used in a variety of commercial and institutional applications. Hydraulic control systems in gas and steam turbines.
Steam turbines are made in a variety of sizes ranging fromsteam turbines are made in a variety of sizes ranging from small steam turbine systems engineering group at woodward, in fort collins, colorado. Low jacking oil pressure can damageturbine generator bearings when turbine speed is toolow for adequate hydrodynamic lubrication. The primary function of the lubrication system is to supply the various journal and thrust bearings with an adequate supply of a suitable lubricant for the formatiom. Some oil analysis laboratories have recognized the need for more comprehensive testing to determine lubricant condition for inservice turbine oils and. Reducing steam flow stops the steam pressure decrease and lowers generator output. A steam turbine oil s most important functions are to. However, the vacuum in the condenser must be broken and the gland steam system switchedoff.
During startup and lowload operation, the sealing steam distribution header has two sources of steam supply. When a gland seal is leaking steam, the humidity of the sunounding air is increased. In this situation, a special purpose steam turbine would be specified for very good reasons. Steam turbines startups 171 prior to switching on the turning gear, oil system is started up. For turbines supplied with options such as forced or circulating lubrication systems, alternative speed control systems, accessories, instrumentation, speed reducers or other special configurations, refer to the appropriate accessory manuals and turbine certified drawing package included in appendix a and appendix b following this manual. Steam turbines for industrial applications ge power systems ger3706d 3 geared turbine generator sets complete packages can include turbine, gear, oil system and generator for quick installation turbine speeds selected to optimize lifecycle costs 15001800 rpm, 4pole generators for 5060 hz applications applications to.
Hydraulic control system in gas turbines a range of systems is required in the fuel circuit for mastering the closedloop con trol and safety functions of a gas turbine. 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. Steam turbine lube oil system is usually required to provide oil for tripandthrottle valve, governor system, power cylinder or similar accessories. Understanding and preventing steam turbine overspeeds by william e. Kwu steam turbine governing system steam turbine x 4 mw htps governing system presentation. Testing for lubricant degradation in a turbine oil system. Provide pressure oil to conditioning system and protection devices. When the turbine is running at a normal speed of 3000rpm, then the desired quantity of oil to the governing systems and the lubrication systems is supplied by this pump. The first steam turbine used for power generation was invented in 1884.
Turbine oils must now simultaneously meet the requirements of both steam and gas turbines. If the hand wheel is turned too quickly the oil valve will be lifted off its seat in the oil power piston, thereby destroying the oil pressure and allowing the valve to close under the action of steam pressure. In the efficient use of energy second edition, 1982. Steam turbines, whether small scale or heavyduty, are crucial for efficient power plants. Depending on the type of installation, this also may include the hydraulic control system, oil. This tutorial provides an overview on large steam turbines systems and their. If the oil pressure is greater than the water pressure, oil will be forced into the cooling water. The steam turbines are widely used in power generation, refineries and petrochemical industries. Three basic types of steam turbine are used to generate power as a byproduct of process or exhaust steamml. This integrated trip block assembly is intended for use on mechanicaldrive or generatordrive steam turbines that use lowpressure 525 bar 73363 psi hydraulic trip oil headers. Our steam turbine portfolio spans across all fuels, from gas and coal to nuclear applications from 100. Ed nelson is a tu rbo machinery consultant based in dickinson, texas. The rings are being installed as replacement parts on the sst300 industrial steam turbine operating at the jsw steel ltd.
Semi package solution the semi package solution consists of only one base frame with integrated oil unit, carrying turbine and gearbox. In the simplest form the overspeed protection system must detect when operating speed is exceeded by a designated percentage often 10% to % and must initiate successful closure of all valves to isolate any and all potential steam energy sources. Overspeed the turbine to check the overspeed trip visually inspect the turbine generator string for. Types of steam turbine an overview sciencedirect topics. Our steam turbines equip 41% of the worlds combinedcycle plants, 30% of fossil power plants, and 50% of the worlds nuclear power plants. A lube oil system will be required unless, of course, the turboexpander is supplied with active magnetic bearings. Auxiliary oil pump can meet the requirements of lubrication system under emergency conditions. Instruction manual for single stage 350, 500, and 700. Evidence of steam, oil or water leakage evidence of steam deposits proper position of all valves condition of all control and trip linkages condition of instrumentation, conduit, wiring, insulation, etc. To provide turbine generator lubricating oil and autostop oil for the turbine trip system, and 4. In case of an emergency the turning gear system may be switchedoff for a maximum of 15 minutes after one day and 30 minutes after 2 days steam turbine shutdown. It is coupled to the turbine rotor through a gear coupling. This is particularly prevalent in steam turbines with high back pressure or high firststage pressure, after the seals are worn. Bloch, claire soares, in turboexpanders and process applications, 2001.
Ever since steam turbines have been built, contamination of the lube oil by watert. In this steam turbines books section you will find handbooks training material and slides related to steam turbine auxiliaries, design and operation and maintenance. Combined heat and power technology fact sheets series. Basically, it is possible to equip the gas turbine with two fuel systems, namely natural gas and fuel oil. Steam turbines are one of the most versatile and oldest prime mover technologies still in general production used to drive a generator or mechanical machinery. In order to maintain the synchronous speed under changing loadgrid or steam conditions, the. The condensing steam turbine is a conventional steam turbine in which the steam exiting the turbine exhaust is condensed to provide the maximum energy capture.
Each valve combination consists of a trip and a control part. Figure 1 is a simple illustration of the general components and travel route of turbine oil in a steam turbine lubrication system. Steam turbine basic parts mechanical engineering site. These are manufactured for outputs from 50 kw e to 30 mw e. This steam then comes in contact with the turbine lube oil, which in most cases is from the same source that powers the hydraulic operator system. May 10, 2020 in this steam turbines books section you will find handbooks training material and slides related to steam turbine auxiliaries, design and operation and maintenance. He is responsible for design and 1nechanical calculations of industrial and medium sized steam turbines.
Steam turbine fires and fires in their oilbearing systems have occurred repeatedly. The eis purpose is to develop and disseminate knowledge, skills and good practice towards a safe, secure and sustainable energy system. The lube oil auxiliary system provides lubricating oil to the steam turbine bearings. Mineral turbine oils for steam, gas and combined cycle turbines is another resource for recommendations regarding selecting testing for condition monitoring of inservice turbine oil. This is the type of steam turbine that will be used in a bottoming cycle chp plant in which waste heat or energy from an industrial process is used to raise steam to generate electricity. Abstract the reliability of a steam turboset is dependent, among other things, on correct fimctioning of its hydraulic lubrication and control system. Dec 18, 2015 place the gland sealing steam system in service.
The steam turbine is just one cost component in a complete chp plant. Understanding and preventing steam turbine overspeeds by. General electric systems technology manual chapter 3. Gas turbines are normally supplied with a lube oil package mounted in the bedplate of the turbine. It will cost more than the gp version, but it will have a lubrication system that makes it less prone to cause unscheduled outages. The oil is then transferred to the main tank where the physically dissolved gasses are removed under vacuum degassed oil. In this article, we will discuss steam turbine basic parts. Our steam turbines work as generator drives or as mechanical. Engineers modelled the hydrogen seal systems and used the simulated. Some oil analysis laboratories have recognized the need for more comprehensive testing to determine lubricant condition for inservice turbine oils and offer. Too high oil pressure increases the risk ofoverpressure failure in the lube oil system. With over a century of experience and continuous development in our steam turbine technology, siemens is a prime partner for your business. Often the boiler is capable of producing moderate pressure steam but the distribution system needs only low pressure steam. Approval issue module 2347 the turbine governing system.
The increasing specific demands imposed upon steam tur bines may bring about new oil system difficulties. In a mixed antioxidant system containing both amines and phenols, the condemning limit is when the amines are. In fulfilling this mission, the ei addresses the depth and breadth of the energy sector, from fuels and fuels distribution to health and safety. Nelson turbomachinery consultant dickinson, texas and perryc. Dresserrand steam turbines a siemens business steam. For understanding the gland sealing system first we have to understand why it is required so there are two main reason. Troubleshooting bearing and lube oil system problems thomas h. Guidance on the preservation and recommissioning of. In addition, a control system is needed and emission reduction hardware may be required depending on local air quality requirements. Instruction manual for single stage 350, 500, and 700 frame. Provide lubrication oil to all bearing shafts of the unit and cooling meanwhile. Particular problems of steam turbine lubrication by. The following protective aetlons listed in the orderofdropping pres.
Combined heat and power technology fact sheet series. Steam turbine governing is the procedure of controlling the flow rate of steam to a steam turbine so as to maintain its speed of rotation as constant. 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. The resulting coke deposits in bearings may cause failure. Steam turbine oil system configuration and operation instructions.
This paper will focus on varnish and other problems seen in steam turbines and will offer suggestions for how. The steam valves are kept open by hydraulic means against the disc springs, respective the steam control valves are position controlled via servo valves. For the purpose of this course, the name turbine lubricating oil system has. The variation in load during the operation of a steam turbine can have a significant impact on its performance.
The control system of a steam turbine may be of the mechanical, hydraulic or electrohydraulic type. As turbine exhaust is connected to a condenser which is operated below atm pressure so there are chances of air ingres or va. Using matlabsimulink software facilities, have been simulated the speed variations, of the steam turbine load unit, connected with a mechanicalhydraulic system, than the speed deviations of. A gas or steam turbine utilizes two types of hydraulic systems. Most industrial installations are in the range 15 mw e. Theacti vatedunloader acts similarly to the loadlimiter, ie. A typical turbine governing system has two unloaders one activated by low condenservacuum. 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. The conventional lube oil system consists of a reservoir, electric cartridge or steam coil heater, lube oil pumps, one and preferably two switchable lube oil. 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. Mccloskey has over 25 years experience in the design, operation, maintenance and troubleshooting of steam turbines, pumps, and related auxiliaries, and holds six patents in mechanical engineering and steam turbine design. Microturbines can burn a variety of fuels, making them useful for resource recovery applications, including landfill gas, digester gas, oil and gas field pumping. Oil supply a single oil supply line lubricates and cools the bearing, governs the mc and operates the hydraulic actuators and safety and protective devices. Pdf simulation of speed steam turbine control system.
More than 120,000 steam turbines delivered worldwide prove that we are a reliable and experienced partner. Ger3706d steam turbines for industrial applications. Lube and seal oil systems, and steam and process gas piping require a thorough cleaning before. Dec 27, 2012 it is coupled to the turbine rotor through a gear coupling.
Steam turbine oil challenges lubrication engineers. Pressurisation of the system is controlled by the cutting in of the ac or dc seal oil pumps when oil overpressure relative to. Over the last 100 years, ge has manufactured and installed a worldwide fleet of steam turbines. As in other process plant machinery trains, the quality of the lube oil system which is supplied with the train has a definite impact on the service factor of the unit.
For low and moderate inlet steam pressure up to 120 bar, a single shell. Turbine lube analysis programs oil analysis, oil sample. 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. In a practical situation the load frequently varies from the designed or economic load and thus there always exists a. They differ in the physical sizes pressure and flow. This plant encompasses more than a century of experience in steam turbine technology. His expertise is in rotating machinery control systems, which includes development work on new technology gas and steam turbine controls. Turbine oils have undergone several advancements as turbine oil specifications have been amended. Turbine stop valve opened slowly until the rotor speed between 300 400 rpm. To provide dry, superheated steam to the low pressure turbines to reduce moisture erosion and to increase plant efficiency. Jul 29, 2015 according to astm d4378 standard practice for inservice monitoring of mineral turbine oils for steam, gas, and combined cycle turbines, the condemning limit of turbine oil is often considered to be 25% remaining antioxidants. It is always necessary to check whether lube oil pumps has started and whether all bearings are supplied with oil.
Using matlabsimulink software facilities, have been simulated the speed variations, of the steam turbine load unit, connected with a mechanicalhydraulic system, than the speed deviations of the. Using this control system, the turbine follows or is slaved to the reactor. By design, this is a builtin contamination path starting at the turbine. The flow rate of steam is monitored and controlled by interposing valves between the boiler and the turbine. Steam and gas turbines are so highly efficient and extremely reliable, its no surprise they. Other fuels such as coal gas, synthesis gas, and naphtha can also be. Turbine scope of work shutdown equipment lock out tag out unit visually inspect the turbine generator string for. Steam turbine governing is the procedure of monitoring and controlling the flow rate of steam into the turbine with the objective of maintaining its speed of rotation as constant. Whatever the requirements are, we provide either bare steam turbine drivers to oems, or we supply complete packages including gears, lube oil systems and controls. If this air has a dew point above the coolest place in the oil system, water con. Oct 21, 2017 in this video we demonstrate turbine lube oil system design, steam turbine lube oil system diagram, turbine lube oil system, steam turbine lube oil system, steam turbine lube oil system diagram, steam. Control of lube oil pressure and temperature, as well as rotor axial displacement and eccentricity is necessary.
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