Extractioncondensing turbines steam turbines steam. 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. Modeling and optimization of a utility system containing multiple. He retired fro m amoco oil company, after more than 36 years in. Extraction cum condensing condensing turbine power. Power turbines condensing turbine double extraction cum condensing the double extraction condensing steam turbine is designed for combined heat and power generation. The gas turbine is a type of internal combustion engine therefore also known as combustion turbine. In general, a steam turbine is a rotary heat engine that converts thermal energy contained in the steam to mechanical energy or to electrical energy. For large industrial chp applications, an extraction condensing type of steam turbine can be used in a combined cycle plant with the steam turbine extracting a portion of the steam for process use. The extraction points of steam from the turbine could be more than one, depending on the temperature levels of. White paper experience capability execution stc generator drivewp page 3 of 6 petrotech steam turbine control ler stc the petrotech stc manages t he operation of the steam turbine from issuance of the start command all the way through the warmup to loaded operation. Smallmedium size steam turbine ensure a high efficiency and reliability for all types of thermal power plants.
The uncontrolled extraction of steam is deployed for process applications with smaller quantity of steam flow and set temperature requirements and low pressure heating application like deaerator for heating solutions. Condensing, extraction and induction turbine introduction the steam turbine, like any other high glade machine, requires, for sustained efficiency and continuity of opelation, a reasonable minimum of care and attention on the part of the operator. The condensing turbine may also have bleed points uncontrolled extractions to satisfy steam demands at medium intermediate. After the steam exits the outlet of the condensing turbine, the steams pressure is so low.
A pressure reducing valve drops the buildings steam pressure. These steam turbines exhaust directly to one or more condensers that maintain vacuum conditions at the discharge of the steam turbine. Such combined cycle power plants are capable of achieving electric generation efficiencies of over 50 percent. In doing so, energy is consumed rather than produced. It is also selected when no high pressure steam is available. Westinghouse double auto extraction condensing steam turbine. Double extraction steam turbines operate similarly as single extraction steam. The choice between backpressure turbine and extractioncondensing turbine depends mainly on the quantities of power and heat, quality of heat, and economic factors. The condensing turbine may also have bleed points uncontrolled extractions to satisfy steam demands at medium intermediate continue reading. Sequential examples, with illustrations, extraction maps and simplified calculations are then given. The extraction condensing turbine is able to change the electric power and the process steam flow independently by adjusting inlet steam flow and process steam flow. Doosan delivering cuttingedge turbine and generator technologies 3. The principal cycle considerations are those of regenerative feedwater heating by turbine extraction steam and of reheating.
All steam turbines can be classified into two categories. As a popular selection of extraction condensing turbine, this steam turbine is a main machine for combined heat and power generation in many industries, such as thermal power generation, chemical engineering, sugar production, papermaking, textile, food processing, and so on. May 05, 2017 all steam turbines can be classified into two categories. Its modern manifestation was invented by charles parsons in 1884. In all turbines the rotating blade velocity is proportional to the steam velocity passing over the blade. Advanced steam turbine controls generator drives a petrotech, inc. Industrial steam turbines steam turbines siemens global. In this analysis energy efficiency, exergy destructions, exergy efficiency and turbine heat rates are evaluated at 40%, 50%, 60%, 70 % and 80 % maximum continuos rating condition of steam turbine. Compounding of steam turbines is the method in which energy from the steam is extracted in a number of stages rather than a single stage in a turbine. Practical steam turbine performance calculations using flex lives steam flex routine or by manual methods a steam turbine s power andor efficiency can be quickly and accurately calculated using flexwares steam flex steam properties program. The majority of large plants in operation or under construction are dualpurpose facilities with a. If the steam is expanded only in a single stage from the boiler pressure to the exhaust pressure, its velocity must be extremely high. In an extracting type turbine, steam is released from various stages of the turbine, and used for industrial process needs or sent to boiler feed water heaters to improve overall cycle efficiency.
The constructional characteristics of these turbines are very similar to condensing turbines from the second admission valve chest it is possible to inject low pressure steam, available in the plant to supply the power required by the plant. What is steam turbine description and characteristics. Multistage extraction and condensing steam turbines are used in most chp 42, 53. Kessels provides for a complete solution for running of a sugar plant with its varied product range of madetoorder application specific steam turbines. Our industrial steam turbines are designed for easy constructability, fast startup and economical operation. Gas turbine based cogeneration system natural gas fired plant gas turbine with unfired waste heat recovery boiler whrb liquid. Extracting type or condensing type steam turbines are common in all applications. Westinghouse double autoextraction condensing steam turbine. In a typical condensing steam turbine, the exhausted steam condenses in the condenser and it is at a pressure well below atmospheric absolute pressure of 0. As a market leader for industrial steam turbines, we offer a comprehensive range of reliable and versatile steam turbines for the power output range from 2 to 250 mw. Delivering cuttingedge turbine and generator technologies. Based on the customer s plant requirements, more than one type of extraction can be obtained from the steam turbine for processes in the plant. Extraction condensing turbines steam turbine steam.
Decreasing the turbine exhaust pressure significantly increases the specific volume of exhausted steam, which requires huge blades in last rows of lowpressure stage of the steam turbine. The condensing turbines take high pressure steam, expand it in turbine nozzles and blades, and exhaust it to a condenser at lower than atmospheric pressure. Steam turbine performance 3 4 2 1 46 45 44 43 42 41 43 42 41 40 39 % % 1. Double extraction cum condensing condensing turbine. Steam turbine working principle and types of steam turbine. Difference between condensing turbine and back pressure. Extraction condensing turbine pdf steam cogeneration scribd. Jun 04, 2018 in this article, we will see the difference between difference between condensing turbine and back pressure turbine.
The primary type of steam turbine is the condensing steam turbine, which has been used for large drive applications above a certain power rating limit say, as a very rough indication, above 8 mw. Nelson turbomachinery consultant dickinson, texas and perryc. Understanding and preventing steam turbine overspeeds by. Steam turbine governing systems and electronic governor retrofit 159 process is required at a specific pressure below the inlet pressure. The turbine manufactured is based on reaction technology of steam turbines. Steam turbine cycles and cycle design optimization. The first outlet extracts the steam with intermediate pressure for the feeding of the heating process while the second outlet extracts the remaining steam with. Pure condensing, condensingextraction, backpressure, or backpressureextraction radial, lateral or axial outlet into the. In an uncontrolled extraction type, a tap is provided at a predetermined stage and a partial stream of steam is drawn out of the turbine. Steam consumption diagram of extraction condensing turbine.
Condensing turbine is selected when the steam demand for the process drivers is greater than the lowpressure process steam requirements. It is principally used when power must be generated with minimum steam consumption. This compact package lends itself to quick steam turbines for industrial applications ge power systems ger3706d 2 20 mw 335 mw 260 mw up to 16,000 rpm 335 mw direct drive stg geared stg feed pump drives mechanical drive units. Both of these steam turbine types have their own operating schemes and ben. Extraction condensing steam turbine manufacturer types of. Double extraction cum condensing condensing turbine power. Extraction condensing turbine an overview sciencedirect topics. Non condensing backpressure turbines an extraction steam turbine is a multistage piece of equipment designed to withdraw steam from one or more stages, at one or more pressures to allow for intermediate pressure steam process applications. The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency from the use of multiple.
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. They can be used like a low pressure body of a two casing turbine, or like a stand alone turbine for low pressure steam conditions. Produce less useful work than a condensing turbine, but since the unused. Adjustment of process steam flow is implemented by the extraction control valve. Aug 01, 2012 turbine generator maintenance 180,068 views. Extraction turbines can be either condensing or non condensing backpressure. In order that the unit may receive such care and attention, it is necessary that the operators. In this article, we will see the difference between difference between condensing turbine and back pressure turbine. Delivered as condensing or backpressure turbine, the modular design concept encompasses standardized bleed extraction andor admission sections, reheating, housings and inletexhaust casings. A highvelocity steam is coming from the nozzles and it strikes the rotating blades which are fitted on a disc mounted on a shaft.
Synthesis and dualobjective optimization of industrial combined heat and. Power turbines condensing turbine extraction cum condensing the extraction cum condensing turbine is designed for combined heat and power generation. From single stage steam turbines utilized for driving critical equipment such as mills, fibrizors, knives and boiler feed pumps, to large multi stage steam turbines for generating power. Understanding and preventing steam turbine overspeeds by william e. Extraction flows may be controlled with a valve, or left uncontrolled. Ger3706d steam turbines for industrial applications.
The double extraction condensing steam turbine is designed for combined heat and power generation. This type of the turbine is applied to the facilities in the mining industry, steel companies, and cement manufactures because of bigger power demand versus steam. It will be necessary to obtain the following operating data from the field. The residual steam is processed in the lowpressure section of the turbine and in the condenser. Unlike with reciprocating engines, for instance, compression, heating and expansion are. The extraction condensing turbines are used when a constant pressure steam flow has to be extracted for process purposes. The first outlet extracts the steam with intermediate pressure for the feeding of the heating process while the second outlet extracts the remaining steam with lowpressure steam for the condensation. What is the difference between fully condensing and back. The turbine has seven bleeder connections for regenerative feed. Request pdf modeling and optimization of a utility system. Exhaust steam conditions, extraction and admission 7 6. Extraction condensing steam turbine pdf steam steam engine. This highvelocity steam produces dynamic pressure on the blades in which blades and shaft both start to rotate in the same direction. Extraction condensing steam turbine pdf steam steam.
Ger3705 ge steam turbine design philosophy and technology. The performance of the steam turbine is governed by the losses occurred in it. Extraction condensing turbine an overview sciencedirect. Principle operation of steam turbines, how to control steam supply, which type. Inside a condensing turbine the steam expands below the atmospheric pressure and then condenses while heating the cooling water in a condenser. Ed nelson is a tu rbo machinery consultant based in dickinson, texas. The turbine manufactured here is based on reaction technology of steam turbines. Advanced steam turbine controls mechanical drives petrotech. Extractioncondensing turbines are employed when steady power generation and steam extraction at a fixed pressure is required. The extraction condensing turbine has more operational flexibility compared with the back pressure turbine, but equipment cost is higher due to additional extraction control valve.
Figure 2 single extraction turbine double extraction turbines double extraction steam turbines operate similarly as single extraction steam turbines, except there are two extraction valves allowing for two extraction points for process steam. In its simplest form, a steam turbine consist of a boiler steam generator, turbine, condenser, feed pump and a variety of auxiliary devices. The two types of steam turbines most widely used are the backpressure and the extraction condensing types fig. China double extraction condensing steam turbine china. The extraction turbine contains two outlets as shown in figure 1. 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. Extraction condensing turbines are employed when steady power generation and steam extraction at a fixed pressure is required. Turbine, double extraction steam turbine, steam turbine manufacturer supplier in china, offering double extraction condensing steam turbine, solar boiler for food processing factory, solar dish stirling concentrator contractor and so on. Reaction turbine 2 iii steam turbine operating range 2 3. The two types of steam turbines most widely used are the backpressure and the extractioncondensing types fig. 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. Goal install a noncondensing backpressure steam turbine that produces energy while. Working principle of steam turbine depends on the dynamic action of steam.
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