The digital governor system underwent comprehensive performance testing at the wellsville, new york facility. 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. Sample frequency sample at oem recommended frequency or, for general guidance, begin with. Therefore, most steam turbine chp systems are characterized by low power to. Show full abstract this version of the pgu90 are discussed, and the oil supply system and structural features of the major equipment in the unit the gas turbine, steam turbine, turbine.
Ehg can be mechanically isolated by closing the secondary oil line from the local. Enables plant to monitor steam turbine generator condition since last overhaul addresses 17 systems components identifies riskrelated recommendations for future outage work colorcoded green. Due to the improved blade and seal concept, turbines operate with up to 2% higher efficiency. Governing system or governor is the main controller of the hydraulic turbine.
Ger3687c speedtronic mark v steam turbine control system. For steam turbines to operate with high reliability and availability, the ability to. Low jacking oil pressure can damage turbine generator bearings when turbine speed is toolow for adequate hydrodynamic lubrication. The oil system generally includes high pressure, bearing. Pdf lecture 27 model steam turbine gov system abdul. Standard practice for design of steam turbine generator oil. Identification of model parameters of steam turbine and.
The primary focus on graphicsanimations in the steam. Regardless of steam turbine type backpressure or extraction the primary objective of most steam turbine chp systems is to. Examined more closely herein are the characteristics of a steam turbines components and evaluation as to possible involvement in loss of control of a machine. Compared to previous steam turbine designs, enhanced platform steam turbines provide a more efficient operation. Steam turbine control systems are being designed with todays technology to. Wi w o functional block diagram of turbine governing system turbine controller 29 feed forward provision k s v s speed controller. Jan 01, 2017 steam turbine control valve, governing and lube oil system subodh kumar tikadar general industrial steam turbine prefers a steam source of 42 kgcm2 600 psi at 482 oc 900 o f. To provide dry, superheated steam to the low pressure turbines.
Depending on the type of installation, this also may include the hydraulic control system, oil. In figure 1 the main oil pump is shown on the left, while one governing oil impeller is shown adjacent to it on the right, and the other is mounted on the. An additional contribution to higher efficiency is the revised steam path realized by specialized steam inlets which ensure high. Axial split casing overspeed trip system governing systems. Video using steam turbine training and governing system training software. The fuel can be any fossil fuel as well as biomass fuels. The selection of the corect and most steam turbines. Modern steam turbines are of two types, reaction and impulse having numerous mechanical arrangements to drive the generators meeting the ever increasing electrical power consumption. In pelton units it requires positioning of spear and deflector. The pressure control system responds to the decrease in throttle pressure by throttling the tcvs andor bpvs decreasing turbine steam flow. The steam turbine is a device for obtaining mechanical work from the energy stored in steam. Course 234 turbine and auxiliaries module seven approval issue pagel8 7. Analysis may vary by laboratory, product supplied or oil condition. Unloaders a typical turbine governing system has two unloaders one activated by low condenservacuum.
Condition monitoring of steam turbine generator governing systems. Pdf lecture 27 model steam turbine gov system abdul hadi. Gas turbine only steam turbine only g s viscosity reported at 40c or 100c, based on oil type or service level. Pdf steam turbine control systems are being designed with todays technology to operate a turbine in a safe and reliable manner. Full oil relay govenor typical trip and control valve unit, the means of valve. What is the purpose of a control oil system in a turbine. In micro hydros electronic loads controllers are used and shunt load bank is adjusted. H02p 904 7 claims abstract of the disclosure a speed governing system for a steam turbine comprises a governor valve for controlling the admission of steam to the turbine, governor valve control means for. The modern large type steam turbine may have thousands of gallons of lubricating oil in its circulation system but the role of this lubricant may well be onetenth. H02p 904 7 claims abstract of the disclosure a speed governing system for a steam turbine comprises a governor valve for controlling the admission of steam to the turbine, governor valve control means for adjusting the opening. Ger3706d steam turbines for industrial applications.
This best practice has been used since 1990 to produce oil systems of highest reliability, and has resulted in unit reliabilities above 99. Speed governing systems for steam turbines filed aug. Hmn series steam turbine courtesy siemens power corporation. Chapter6 hydroturbine governing system iit roorkee. Steam turbine training and governing system training youtube. Turbines are driven directly by gases produced by hot gases in gas turbines the combustion of natural gas or oil. Steam turbine governing systems and electronic governor retrofit 159 process is required at a specific pressure below the inlet pressure. To act as the shutdown and speed control mechanism. In throttle governing the pressure of steam is reduced at the turbine entry thereby decreasing the availability of energy. Steam turbine governing national power training institute. Simulation of speed steam turbine control system cyberleninka. Turbine oil system it supplies oil for the lubrication of the turbine and generator bearings, for actuation of various components of governing and control system and seal oil to generator seals in the event of any emergency. Other fuels such as coal gas, synthesis gas, and naphtha can also be.
A turbine whose initial steam is significantly superheated. Approval issue module 2347 the turbine governing system. Also, when the turbine is shutting down, then the jacking oil system comes into operation so that the hot shaft does not rest on the white metal of the bearing. Bookmark file pdf chapter 6 hydro turbine governing system ahec. Steam enters the turbine with a high energy content and leaves after giving up most of it. Mar 05, 2021 the governing and control system of a steam turbine generator controls the entry of steam during starting up to service speed and provides close speed control for synchronization to the electric power system. These mechanisms are indicated in table 1 along with the resultant damage and typical causes of failure. Turbine governing system 1 turbine governing system presented by. In this type of governing the steam is throttled down to lower pressure. D hold the nozzles of the stage and admit steam to moving blades if choice d is selected set score to 1. Three oil impellers or pumps are mounted on the turbine shaft. After starting the oil system and turning gear, the condensation system can be started, that is cooling water, air ejection and condensate pumping systems. Therefore, turbine governing is the procedure of controlling the flow rate of steam to a steam turbine.
For highest electrical conversion efficiency, the steam will be condensed at the exit of the steam turbine, creating the largest pressure drop possible across the turbine blades. Using a spare nuclear turbine, the system was tested uncoupled to a pump, with a steam pressure of 900 pounds at a temperature of 550 degrees fahrenheit steam energy rating of approximately 1,200 pounds. Using this control system, the turbine follows or is slaved to the reactor. State thedifference between latchedand unlatchedronbacks. The structure of electro hydraulic controller is comprises of following subcontrol loops. Throttle governing throttle governing big turbines in larger steam turbines an oil operated servo mechanism is used in order to enhance the. Feb 01, 2007 a steam turbine oil s most important functions are to. When designing hydraulic systems, it is critical to receive the specifications for the turbine andor project. Once synchronized, the governing system controls the output of the machine. Proportional integral load load ref speed ref speed controller load controller selection logic e h. Proportional integral load load ref speed ref speed controller load controller selection logic e h to hyd. The turbine will not start unless the control oil pressure has been substantiated, and as most interlocks or shutdowns use it to dump the oil pressure and thence shut the throttle valve, its a v. Power plant steam turbine auxiliaries play the same role, and are best described by systems such as steam system superheated expanding through the turbine, exiting as low pressure steam to the condenser. System overview the turbine oil hydraulic system consists of one or two designs.
Data and experiences of one insurance company in several areas failure for steam turbines were presented by clark 1. The highpressure steam from the boiler is expanded in nozzles to create a highvelocity jet of steam. So, basically steam turbine governing system is a process where turbine maintains a steady output speed irrespective of variation of load. The mark v family of turbine controls for the 1990s, offers a common control architecture for small, medium, and large steam turbines, turbine generator monitoring systems, generator excitation systems, and gas turbine controls. Us3427464a speed governing systems for steam turbines. Operation of the typical hydraulic actuator of a turbine steam valve and purity of the. Hydrodynamic governing of lmw turbine, speed governor and follow up piston. It also supplies oil for the jacking and hydraulic turning gear during startup and shut down. Gland steam must have appropriate temperature and pressure which must be controlled during startup. The different types of steam turbine governor of are.
In the few candu units wh turbine lubricating oil, instead of frf, is used in. Understanding and preventing steam turbine overspeeds by. In both the noncondensing and condensing type units, a single or double controlled extraction may be considered, depending on the number of openings that steam exits the turbine prior to the exhaust figure 6. Modelling of steam turbine and its governing system. This will normally include all power used for control, lubricati.
Hydraulic control systems in gas and steam turbines. 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. Pdf simulation of speed steam turbine control system. Precommissioning activities on steam turbine and its systems pre commissioning is a preparatory activity for commissioning of turbine and its systems following are a few major pre commissioning activities of steam turbine and its system. Simultaneously, gland steam system is started to prevent air inleakage. Condition monitoring of steam turbine generator governing. Before admitting steam, the turbine is turned at a slow speed by turning gear. Rotors, bearings, sealing glands singledisc, tworow curtis impulsetype wheels, shouldered, keyed. Pressure oil system with oil servomotor is most commonly used actuator. Chapter 6 hydro turbine governing system ahec nacfe. Figure 1 is a simple illustration of the general components and travel route of turbine oil in a steam turbine lubrication system. The variation in load during the operation of a steam turbine can have a significant impact on its performance. Reducing steam flow stops the steam pressure decrease and lowers generator output.
Maintenance and overhaul of steam turbines wgp42 05. 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. General electric systems technology manual chapter 3. Gland sealing, control oil, seal oil, lubricating oil systems.
Alternate governing systems are supplied when required for some operating conditions or when specified by the client. Steam turbine control valve, governing and lube oil system. Steam turbine blading can be subjected to several failure mechanisms in service. This part of the system is used to provide a constant power setting to the turbine in order to get a constant output under steady state condition. The following protective aetlons listed in the orderofdropping pres. Simulation of speed steam turbine control system sciencedirect. Jun 16, 2014 turbine governing system an overview 1.
If steam pressure decreases the steam flow rate and temperature are also decrease so in this system loses will be much more. Combined cycle gas turbine plants are driven by both steam and gas. Governing systems the woodward tg series constant speed oil relay governor is standard equipment for rlha steam turbines. The second system is nozzle governing which changes the flow rate at constant turbine inlet pressure and temperature. Too high oil pressure increases the risk ofoverpressure failure in the lube oil system. Steam turbine training and governing system training. Basically, it is possible to equip the gas turbine with two fuel systems, namely natural gas and fuel oil. The general features and selection criteria and use depending on the type of steam turbine are summarized in.
They gener ate power by burning natural gas in a gas turbine and use residual heat to generate additional electricity from steam. Approval issue course 234 turbine and auxiliaries module 10 stressed that these consequences. A simple steam turbine chp system needs a boiler and steam generator to raise the steam to drive the unit. Power plant steam turbine auxiliaries bright hub engineering. It also provides machine protection, typically using various devices to initiate a trip in emergency conditions. To provide turbine generator lubricating oil and autostop oil for the turbine trip system, and. A full oil relay is used on some single valve designs depending on. Steam turbinegenerator overhaul and inspection guidelines.
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