The steam turbine generator is the primary power conversion. Chapter6 hydroturbine governing system iit roorkee. Bearings and lubrication for small steam turbines efficient. Steam turbine governing system and electronic governor retrofit.
Steam for turbine is provided by pp330140p55 type steam generator, a oncethrough coalfired boiler 8. Governing system or governor is the main controller of the hydraulic turbine. The power from extraction turbine is generated as an advantage of the generated steam, though our prime use of steam is for processes. If this high velocity steam is applied to a properly shaped turbine blade, the steam will change in direction due to the shape of the blade. Impulse turbine and reaction turbineprinciple, working and. Steam turbinesgenerators and auxiliary systems program 65. The typical main turbine in nuclear power plants, in which steam expands from pressures about 6 mpa to pressures about 0.
Theacti vatedunloader acts similarly to the loadlimiter, ie. Impulse turbine and reaction turbineprinciple, working. It then emerged through two opposing curved tubes, just as water issues from a rotating lawn. Modern steam turbines use essentially the same concept but many detailed improvements have been made in the intervening years mainly to improve turbine efficiency. Improved steam turbine design for optimum efficiency and reduced cost of ownership deshpande, srikanth 2017 document version. The first device that can be classified as a reaction steam turbine is the aeolipile proposed by hero of alexandria, during the 1st century ce. A steam turbine is a device that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Modern large steam turbine plants over 500mw have efficiencies of about 4045%. With this way the production of work is higher and the title of the steam in the exit of the turbine is. State thedifference between latchedand unlatchedronbacks. Applications of steam turbines power generation transport 4. The steam turbine generator is used today to produce approximately 85% of the electricity in the united states. Fundamentals of steam turbine systems principles of operation the motive power in a steam turbine is obtained by the rate of change in momentum of a high velocity jet of steam impinging on a curved blade which is free to rotate.
The noncondensing steam turbine uses highpressure steam for the rotation of blades. Nevertheless modern steam turbines are very efficient and operate with internal efficiencies within the range of 80 percent to 90 percent depending upon the steam conditions. Publishers pdf, also known as version of record link to publication citation for published version apa. Because up to 70% of outages planned for steam power plants involve work on the turbine, power producers continually seek ways to optimize operation and maintenance activities on aging turbinegenerator fleets. Electromagnetic induction is based on faradays law of induction.
Its modern manifestation was invented by charles parsons in 1884 the steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple stages in the expansion of the steam, which results. The steam expands in two or more stages at intermediate pressures. A typical turbine governing system has two unloaders one activated by low condenservacuum. This service generally calls for a backpressure noncondensing steam turbine. The variation in load during the operation of a steam turbine can have a significant impact on its performance. Nasa images solar system collection ames research center. Improved steam turbine design for optimum efficiency and. 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.
The first is the one described above and is known as the internal efficiency. Steam turbine 1 content chapter description page i purpose 2 ii steam turbine types 2 2. Turbine turbine history of steam turbine technology. Their unplanned or forced outage rates are typically less than 2% or less than one week per year. Turbine history of steam turbine technology britannica. In this case, the gas turbines waste heat is recovered to produce the steam required by the steam 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.
Control and governing of steam turbines, university of buenos aires, own edition, 1998. Its modern manifestation was invented by charles parsons in 1884. Dec 18, 2015 place the gland sealing steam system in service. Operation and maintenance schedule of a steam turbine plant. Governing system of the turbine does the following functions. Figure 4 shows steam process in enthalpy against entropy diagram of curtis and single row rateau turbine. Cylinder efficiency for hp and ip turbines the steam turbine. It has almost completely replaced the reciprocating piston steam engine primarily because of its greater thermal efficiency and higher powertoweight ratio. For example, a steam turbine extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating shaft.
In presented example, two cases steam turbine, which consists of high pressure part. The generator connected to the shaft takes the mechanical energy produced by the turbine and converts it to electrical energy through the use of electromagnetic induction. In principle, the impulse steam turbine consists of a casing containing stationary steam nozzles and a rotor with moving or rotating buckets. Turbine speed governing system plz use speakers youtube. 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. Turbine governing systeman overview free download as powerpoint presentation. Take, for instance, a 600 kw steam turbine selected to drive a small, but essential, process gas compressor. Steam turbine control systems are being designed with todays technology to operate a turbine. In case of turbines with cooling water preheating and lowpressure lp. It then emerged through two opposing curved tubes, just as water issues from a rotating lawn sprinkler. Simultaneously, gland steam system is started to prevent air inleakage. In this device, steam was supplied through a hollow rotating shaft to a hollow rotating sphere. The pressure control system responds to the decrease in throttle pressure by throttling the tcvs andor bpvs decreasing turbine steam flow. It will cost more than the gp version, but it will have a lubrication system that makes it less prone to cause unscheduled outages.
Following figures show steam process in steam turbine. Consider steam turbine drives for rotating equipment steam turbines are well suited as prime movers for driving boiler feedwater pumps, forced or induceddraft fans, blowers, air compressors, and other rotating equipment. There are two commonly used cylinder efficiency definitions for hp and ip turbines. General electric systems technology manual chapter 3. When the steam passes through the stationary nozzles and is directed at high velocity against the rotor buckets. Working principle of steam turbine depends on the dynamic action of steam. Steam turbine governing systems and electronic governor retrofit by. The law states that a wire conductor that creates movement through a magnetic field will generate an electrical current. Steam turbine plants generally have a history of achieving up to 95% availability and can operate for more than a year between shutdowns for maintenance and inspections. Automation and control of electric power generation and. The pressure of outlet steam depends on in the load, therefore, this turbine.
A highvelocity steam is coming from the nozzles and it strikes the rotating blades which are fitted on a disc mounted on a shaft. Using this control system, the turbine follows or is slaved to the reactor. Improved steam turbine design for optimum efficiency and reduced cost of ownership. 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. Pdf the turbine control system is one of the key control loops in the dynamic performance of steam power generation units.
This means that a gas turbine and a steam turbine are combined into a single unit. This steam then leaves the turbine at the atmospheric pressure or lower pressure. The second includes the effect of the pressure drop through the stop and governor valves on the hp turbine and intercept, stop and governor valves on the ip turbine and is known as the external efficiency fig 1. Governing of steam turbine is the procedure of controlling the flow rate of steam to a steam turbine so as to maintain the speed of the turbine fairly constant irrespective of load on the turbine. This highvelocity steam produces dynamic pressure on the blades in which blades and shaft both start to rotate in the same direction.
Using matlabsimulink software facilities, have been simulated the speed variations, of the steam turbineload unit, connected with a mechanicalhydraulic system, than the speed deviations of the steam turbineload unit, to different load deviations, proportional and proportionalintegrative control algorithms. In fact, the steam will issue from the nozzle in the form of a high speed jet. Despite efforts to develop alternative energy converters, electricity from steam will continue, for many years, to provide the power that energizes the united states and world economies. Pdf session 6 session 6 steam turbine governing steam.
Steam turbine is the widely use as a prime mover in power plants, refineries, petrochemical plants, food processing plants, power plants etc. In a practical situation the load frequently varies from the designed or economic load and thus there always exists a considerable. The steam turbine unlike the reciprocating steam engine which operates due to the pressure energy of system operates due to dynamic action of the steam. State a typical ilulge ofnmbackrates expressed as a per centageoffull powerper second. The governor is a control component with advanced protections for the turbine which ensure safe operation of the turbine.
Steam turbine working principle and types of steam turbine. Because the turbine generates rotary motion, it is particularly suited to driving electrical generators about 90% of all electricity generation in the united states 1996 is by use of steam turbines 1 wiser. Operation and maintenance schedule of a steam turbine. Session 6 session 6 steam turbine governing steam turbine governing system system. Consider steam turbine drives for rotating equipment.
Elec0047 power system dynamics, control and stability. Pdf power plant lecture notes chapter4 steam turbine. The article presents a concept of a combined large power ship propulsion system consisting of the leading diesel main engine, associated with a power gas turbine and the steam turbine system which. Simulation of speed steam turbine control system cyberleninka. In a practical situation the load frequently varies from the designed or economic. Steam generator, turbine, pump, nozzle, throttling, the mathematical expression of the 1st law for a closed system. The governor does this function by controlling the steam flow through the turbine by adjusting the control value. Nov 01, 2007 take, for instance, a 600 kw steam turbine selected to drive a small, but essential, process gas compressor.
Approval issue module 2347 the turbine governing system. The governing systems for thermal and hydro generating plants are. Definition a steam turbine is a prime mover in which the potential energy of the steam is transformed into kinetic energy and later in its turn is transformed into the mechanical energy of rotation of the turbine shaft. Prior to supplying steam to the turbine, the steam supply pipelines have to be drained and heated up. For one example generation unit, the domestictype 300 mw steam turbine is a cylinder, two subcritical two exhausts reheat condensing steam turbine manufactured. Steam turbine gets heat energy in the form of superheated steam from steam generator. Turbines have internal sealing systems between the rotat. A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Pdf simulation of speed steam turbine control system. In noncondensing turbines or backpressure turbines, steam exhausts at a pressure greater than. Schematic diagram of 200 mw unit 8 construction of the steam generator is carried out in two distinct bodies, symmetrical with the axis of the group, operating in parallel to the k2001 steam turbine. With an appendix on gas turbines and the future of heat engines. Steam process in steam turbine steam entrance to turbine through governor valv e to control steam capacity and therefore to control turbine speed.
Steam turbine governing and its mechanism ece tutorials. Steam turbines are used in all of our major coal fired power stations to drive the generators or alternators, which produce electricity. Steam power plants are designed within a large rating. Course 234 turbine and auxiliaries module seven approval issue pagel8 7. Steamturbine principles and practice by croft, terrell, 1880publication date 1923 topics steamturbines. Steam turbine governing systems and electronic governor retrofit 159 process is required at a specific pressure below the inlet pressure. There are two classical types of turbine stage designs. Extraction condensing steam turbine with cogeneration system. Reducing steam flow stops the steam pressure decrease and lowers generator output. Pdf steam turbine find, read and cite all the research you need on researchgate. In this article, we see about the impulse turbine and reaction turbine principle, working and difference.
The acceleration, which may be a change in either magnitude or direction of a stream of fluid, produces a turning moment on a rotating shaft. Steam turbine definition is a turbine that is driven by the pressure of steam discharged at high velocity against the turbine vanes. Reaction turbine 2 iii steam turbine operating range 2 3. With this method the steam do not expands in one only stage until the condenser pressure. Governor control system for hydro turbines is basically a feed back control. A steam turbine is a mechanical device that extracts thermal energy from pressurized steam and transforms it into mechanical work. The steam from the boiler is expanded in a nozzle, resulting in the emission of a high velocity jet. Gland steam must have appropriate temperature and pressure which must be controlled during startup. The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple. The first steam turbine used for power generation was invented in 1884. Steam turbine definition of steam turbine by merriamwebster. Pdf robust controller design for governing steam turbine power. In this situation, a special purpose steam turbine would be specified for very good reasons.
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