WorldWideScience

Sample records for superheated steam-turbine cycles

  1. Regenerative superheated steam turbine cycles

    Science.gov (United States)

    Fuller, L. C.; Stovall, T. K.

    1980-01-01

    PRESTO computer program was developed to analyze performance of wide range of steam turbine cycles with special attention given to regenerative superheated steam turbine cycles. It can be used to model standard turbine cycles, including such features as process steam extraction, induction and feedwater heating by external sources, peaking, and high back pressure. Expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses are used to calculate cycle heat rate and generator output. Program provides power engineer with flexible aid for design and analysis of steam turbine systems.

  2. New features and applications of PRESTO, a computer code for the performance of regenerative, superheated steam turbine cycles

    Science.gov (United States)

    Choo, Y. K.; Staiger, P. J.

    1982-01-01

    The code was designed to analyze performance at valves-wide-open design flow. The code can model conventional steam cycles as well as cycles that include such special features as process steam extraction and induction and feedwater heating by external heat sources. Convenience features and extensions to the special features were incorporated into the PRESTO code. The features are described, and detailed examples illustrating the use of both the original and the special features are given.

  3. Gas--steam turbine combined cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-10-01

    The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

  4. A new approach in CHP steam turbines thermodynamic cycles computations

    Directory of Open Access Journals (Sweden)

    Grković Vojin R.

    2012-01-01

    Full Text Available This paper presents a new approach in mathematical modeling of thermodynamic cycles and electric power of utility district-heating and cogeneration steam turbines. The approach is based on the application of the dimensionless mass flows, which describe the thermodynamic cycle of a combined heat and power steam turbine. The mass flows are calculated relative to the mass flow to low pressure turbine. The procedure introduces the extraction mass flow load parameter νh which clearly indicates the energy transformation process, as well as the cogeneration turbine design features, but also its fitness for the electrical energy system requirements. The presented approach allows fast computations, as well as direct calculation of the selected energy efficiency indicators. The approach is exemplified with the calculation results of the district heat power to electric power ratio, as well as the cycle efficiency, versus νh. The influence of νh on the conformity of a combined heat and power turbine to the grid requirements is also analyzed and discussed. [Projekat Ministarstva nauke Republike Srbije, br. 33049: Development of CHP demonstration plant with gasification of biomass

  5. Microfabricated rankine cycle steam turbine for power generation and methods of making the same

    Science.gov (United States)

    Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

    2009-01-01

    In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

  6. Open-Cycle Gas Turbine/Steam Turbine Combined Cycles with synthetic fuels from coal

    Science.gov (United States)

    Shah, R. P.; Corman, J. C.

    1977-01-01

    The Open-Cycle Gas Turbine/Steam Turbine Combined Cycle can be an effective energy conversion system for converting coal to electricity. The intermediate step in this energy conversion process is to convert the coal into a fuel acceptable to a gas turbine. This can be accomplished by producing a synthetic gas or liquid, and by removing, in the fuel conversion step, the elements in the fuel that would be harmful to the environment if combusted. In this paper, two open-cycle gas turbine combined systems are evaluated: one employing an integrated low-Btu gasifier, and one utilizing a semi-clean liquid fuel. A consistent technical/economic information base is developed for these two systems, and is compared with a reference steam plant burning coal directly in a conventional furnace.

  7. DESIGN OF COMBINED CYCLE GENERATION SYSTEM WITH HIGH TEMPERATURE FUEL CELL AND STEAM TURBINE

    Institute of Scientific and Technical Information of China (English)

    Yu Lijun; Yuan Junqi; Cao Guangyi

    2003-01-01

    For environment protection and high efficiency, development of new concept power plant has been required in China. The fuel cell is expected to be used in a power plant as a centralized power station or distributed power plant. It is a chemical power generation device that converts the energy of a chemical reaction directly into electrical energy and not limited by Carnot cycle efficiency. The molten carbonate fuel cell (MCFC) power plant has several attractive features I.e. High efficiency and lower emission of Nox and Sox. A combined cycle generation system with MCFC and steam turbine is designed. Its net electrical efficiency LHV is about 55%.

  8. Steam Turbines

    Science.gov (United States)

    1981-01-01

    Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

  9. Low cycle fatigue analysis of a last stage steam turbine blade

    Directory of Open Access Journals (Sweden)

    Měšťánek P.

    2008-11-01

    Full Text Available The present paper deals with the low cycle fatigue analysis of the low pressure (LP steam turbine blade. The blade is cyclically loaded by the centrifugal force because of the repeated startups of the turbine. The goal of the research is to develop a technique to assess fatigue life of the blade and to determine the number of startups to the crack initiation. Two approaches were employed. First approach is based on the elastic finite element analysis. Fictive 'elastic' results are recalculated using Neuber's rule and the equivalent energy method. Triaxial state of stress is reduced using von Mises theory. Strain amplitude is calculated employing the cyclic deformation curve. Second approach is based on elastic-plastic FE analysis. Strain amplitude is determined directly from the FE analysis by reducing the triaxial state of strain. Fatigue life was assessed using uniaxial damage parameters. Both approaches are compared and their applicability is discussed. Factors that can influence the fatigue life are introduced. Experimental low cycle fatigue testing is shortly described.

  10. Brush Seals for Improved Steam Turbine Performance

    Science.gov (United States)

    Turnquist, Norman; Chupp, Ray; Baily, Fred; Burnett, Mark; Rivas, Flor; Bowsher, Aaron; Crudgington, Peter

    2006-01-01

    GE Energy has retrofitted brush seals into more than 19 operating steam turbines. Brush seals offer superior leakage control compared to labyrinth seals, owing to their compliant nature and ability to maintain very tight clearances to the rotating shaft. Seal designs have been established for steam turbines ranging in size from 12 MW to over 1200 MW, including fossil, nuclear, combined-cycle and industrial applications. Steam turbines present unique design challenges that must be addressed to ensure that the potential performance benefits of brush seals are realized. Brush seals can have important effects on the overall turbine system that must be taken into account to assure reliable operation. Subscale rig tests are instrumental to understanding seal behavior under simulated steam-turbine operating conditions, prior to installing brush seals in the field. This presentation discusses the technical challenges of designing brush seals for steam turbines; subscale testing; performance benefits of brush seals; overall system effects; and field applications.

  11. Comparison of Integrated Gasifier-Combined Cycle and AFB-steam turbine systems for industrial cogeneration

    Science.gov (United States)

    Nainiger, J. J.; Abbott, J. M.; Burns, R. K.

    1981-01-01

    In the cogeneration technology alternatives study (CTAS) a number of advanced coal fired systems were examined and systems using a integrated coal gasifier IGCC or a fluid bed combustor AFB were found to yield attractive cogeneration results in industrial cogeneration applications. A range of site requirements and cogeneration sizing strategies using ground rules based on CTAS were used in comparing an IGCC and an AFB. The effect of time variations in site requirements and the sensitivity to fuel and electricity price assumptions are examined. The economic alternatives of industrial or utility ownership are also considered. The results indicate that the IGCC system has potentially higher fuel and emission savings and could be an attractive option for utility ownership. The AFB steam turbine system has a potentially higher return on investment and could be attractive assuming industrial ownership.

  12. Comparison of Integrated Gasifier-Combined Cycle and AFB-steam turbine systems for industrial cogeneration

    Science.gov (United States)

    Nainiger, J. J.; Abbott, J. M.; Burns, R. K.

    In the cogeneration technology alternatives study (CTAS) a number of advanced coal fired systems were examined and systems using a integrated coal gasifier IGCC or a fluid bed combustor AFB were found to yield attractive cogeneration results in industrial cogeneration applications. A range of site requirements and cogeneration sizing strategies using ground rules based on CTAS were used in comparing an IGCC and an AFB. The effect of time variations in site requirements and the sensitivity to fuel and electricity price assumptions are examined. The economic alternatives of industrial or utility ownership are also considered. The results indicate that the IGCC system has potentially higher fuel and emission savings and could be an attractive option for utility ownership. The AFB steam turbine system has a potentially higher return on investment and could be attractive assuming industrial ownership.

  13. Effect of Gas/Steam Turbine Inlet Temperatures on Combined Cycle Having Air Transpiration Cooled Gas Turbine

    Science.gov (United States)

    Kumar, S.; Singh, O.

    2012-10-01

    Worldwide efforts are being made for further improving the gas/steam combined cycle performance by having better blade cooling technology in topping cycle and enhanced heat recovery in bottoming cycle. The scope of improvement is possible through turbines having higher turbine inlet temperatures (TITs) of both gas turbine and steam turbine. Literature review shows that a combined cycle with transpiration cooled gas turbine has not been analyzed with varying gas/steam TITs. In view of above the present study has been undertaken for thermodynamic study of gas/steam combined cycle with respect to variation in TIT in both topping and bottoming cycles, for air transpiration cooled gas turbine. The performance of combined cycle with dual pressure heat recovery steam generator has been evaluated for different cycle pressure ratios (CPRs) varying from 11 to 23 and the selection diagrams presented for TIT varying from 1,600 to 1,900 K. Both the cycle efficiency and specific work increase with TIT for each pressure ratio. For each TIT there exists an optimum pressure ratio for cycle efficiency and specific work. For the CPR of 23 the best cycle performance is seen at a TIT of 1,900 K for maximum steam temperature of 570 °C, which gives the cycle efficiency of 60.9 % with net specific work of 909 kJ/kg.

  14. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

    1976-01-01

    The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

  15. User's instructions for ORCENT II: a digital computer program for the analysis of steam turbine cycles supplied by light-water-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, L.C.

    1979-02-01

    The ORCENT-II digital computer program will perform calculations at valves-wide-open design conditions, maximum guaranteed rating conditions, and an approximation of part-load conditions for steam turbine cycles supplied with throttle steam characteristic of contemporary light-water reactors. Turbine performance calculations are based on a method published by the General Electric Company. Output includes all information normally shown on a turbine-cycle heat balance diagram. The program is written in FORTRAN IV for the IBM System 360 digital computers at the Oak Ridge National Laboratory.

  16. User's manual for PRESTO: A computer code for the performance of regenerative steam turbine cycles

    Science.gov (United States)

    Fuller, L. C.; Stovall, T. K.

    1979-01-01

    Standard turbine cycles for baseload power plants and cycles with such additional features as process steam extraction and induction and feedwater heating by external heat sources may be modeled. Peaking and high back pressure cycles are also included. The code's methodology is to use the expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses to calculate the heat rate and generator output. A general description of the code is given as well as the instructions for input data preparation. Appended are two complete example cases.

  17. Cogeneration steam turbines from Siemens: New solutions

    Science.gov (United States)

    Kasilov, V. F.; Kholodkov, S. V.

    2017-03-01

    The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions.

  18. Modern geothermal power: GeoPP with geothermal steam turbines

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  19. A review on the use of gas and steam turbine combined cycles as prime movers for large ships. Part II: Previous work and implications

    Energy Technology Data Exchange (ETDEWEB)

    Haglind, Fredrik [Technical University of Denmark, Department of Mechanical Engineering, Building 402, DK-2800 Kgs. Lyngby (Denmark)

    2008-12-15

    The aim of the present paper is to review the prospects of using combined cycles as prime movers for large ships, like, container ships, tankers and bulk carriers. The paper is divided into three parts of which this paper constitutes Part II. In Part I, the environmental and human health concerns of international shipping were outlined. The regulatory framework relevant for shipping and the design of combined cycles were discussed. Here, previous work and experience are reviewed, and an overview of the implications of introducing combined cycles as prime movers is included. In Part III, marine fuels are discussed and the pollutant emissions of gas turbines are compared with those of two-stroke, slow-speed diesel engines. In the past, combined cycles of COGAS and COGES configurations have been considered for ship propulsion. Another application where gas turbine-based systems have been considered as prime movers is for LNG ships, which are traditionally powered by steam turbines with gas-burning boilers. Previous experience for a cruiser shows that combined cycles weigh less and require a smaller volume than diesel engines, resulting in increased passenger capacity and/or voyage performance. Diesel engines respond faster to a load change than combined cycles. Provided parts within the steam cycle are warm, the start-up times of combined cycles and diesel engines are similar. (author)

  20. Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

    Science.gov (United States)

    Nainiger, J. J.

    1978-01-01

    An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

  1. Maintenance of Power Steam Turbine

    OpenAIRE

    Kapelovich, Boris; Khmelnik, Solomon; Kapelovich, David; Benenson, Evgeny

    2008-01-01

    The diagnostics system of the power steam turbine is offered. It can be executed also in the form of telediagnostic system. The system is presented on a site http://turbo.mic34.com/ System engineering can is ordered to authors.

  2. Best possible cycle chemistry control in steam turbine plants; Baesta moejliga oevervakning av vattenkemin i anlaeggningar med aangturbin

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Mats [Hellman Vatten AB, Stockholm (Sweden)

    2004-11-01

    A project has been conducted of a large number of power and pulp plants in Sweden. Production managers and those responsible for water quality control were visited and interviewed. In addition, a research of cycle chemistry literature has been conducted to determine what has been done in other countries. The review of this literature shows that the Electric Power Research Institute in the USA and ESKOM in South Africa are in the forefront regarding QA/QC and have come a long way in water control management. A key requirement for successful plant cycle chemistry is corporate management support. The project makes it clear that cycle chemistry control was best at plants where production management was aware of the importance of high water quality. There is a real need for feed water technique and water quality education at all company levels. The objective should be that 'everyone should know the importance of right water quality'. Personnel without an education in chemistry often regard cycle chemistry as somewhat complicated. Better understanding and better working cycle chemistry control can be obtained by making the control easier and clearer for persons without training in chemistry. Extensive on-line instrumentation with well-designed systems for presenting the data, by-far, gives the best cycle chemistry control. It is important to have a holistic view when water treatment systems and on-line instrumentation are planned. It is not the amount of instruments or the number of chemistry personnel that is important. The important thing is to ensure that all functions needed fit together in the best way possible. Today, when cycle chemistry monitoring is heavily dependent on on-line instrumentation, the reliability of the instruments is crucial. Therefore, it is important to have well-established routines for maintenance, calibration and service. In order to decrease forced outages of plants due to poor cycle chemistry, the focus of chemistry control should

  3. 核电汽轮机转子在低周疲劳与高周疲劳交互作用下裂纹扩展寿命的研究%Study on Crack Propagation Life under Low Cycle Fatigue and High Cycle Fatigue of Nuclear Steam Turbine Rotors

    Institute of Scientific and Technical Information of China (English)

    史进渊

    2015-01-01

    The calculation and assessment methods for the crack propagation life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors is presented. The low high fatigue cycle stress amplitude and stress range as well as the crack propagation life calculation methods for low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are introduced. The calculation and assessment methods for the crack propagation calendar life under low cycle fatigue and high cycle fatigue of nuclear steam turbine rotors are given together with an application example for calculation and improvement of the fatigue crack propagation calendar life of a low pressure welded rotor for 1 000 MW nuclear steam turbines. The example results indicate that effect of the high cycle fatigue on the fatigue crack propagation calendar life of nuclear steam turbine rotors is bigger, it is necessary that assessment for the crack propagation life under low cycle fatigue and high cycle fatigue of rotors in the rotor structure design of new development for nuclear steam turbine and the rotor safety assessment for operation steam turbine for nuclear power plants.%提出核电汽轮机转子在低周疲劳与高周疲劳交互作用下裂纹扩展寿命的计算与评定方法.介绍核电汽轮机转子的低周疲劳与高周疲劳的应力幅与应力范围、低周疲劳裂纹扩展寿命与高周疲劳扩展寿命的计算方法.给出了核电汽轮机转子在低周疲劳与高周疲劳交互作用下裂纹扩展日历寿命的计算与评定方法,以及1 000 MW级核电汽轮机焊接低压转子疲劳裂纹扩展日历寿命的计算与改进的应用实例.结果表明,高周疲劳对汽轮机转子疲劳裂纹扩展日历寿命有比较大的影响,新研制核电汽轮机的转子结构设计和在役核电汽轮机的转子安全性评定,需要评估转子在低周疲劳与高周疲劳交互作用下裂纹扩展寿命.

  4. New type steam turbine for cogeneration

    Institute of Scientific and Technical Information of China (English)

    He Jianren; Yang Qiguo; Xu Damao

    2010-01-01

    A concept of energy saving & efficiency improving from cold source for cogeneration steam turbine was discussed herein.A new type"NCB"cogeneration steam turbine was proposed,which could considerably increase heat supply capacity,thermal efficiency and electric power.Taking 300 MW cogeneration steam turbine as an example,the results show that heat supply capacity reaches the maximum,i.e.increases by 30%,thermal efficiency is improved by12%,and electric power is enhanced by 15 MW during peak heat load.

  5. Robust velocity and load control of a steam turbine in a combined cycle thermoelectric power station; Control robusto de velocidad y carga de una turbina de vapor en una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Archundia, Enrique

    1998-12-31

    This research work is oriented to design, develop and validate an algorithm of modern control, that allows obtaining better performances in the control of speed of a steam turbine pertaining to a combined cycle thermoelectric power station, in all the operation interval, as well as obtaining better performances in the control of the amount of generated megawatts by the same when it is connected to an electric power generator, comparing the performance with the one obtained by means of the existing conventional controller. The changes in the speed reference or load are at the request of the operator and they always occur in incline form, indicating the rapidity with which it is desired to carry out the change of value in the reference. This is the reason for why the main objective of the control to design is to make a good follow up to references of the incline type. In the subsystem of the existing steam turbine the disadvantage is that the valves that regulate the steam flow to the turbine present a connection with the bypass valve that allows to derive the steam flow towards the main condenser without going through the turbine. It is for this reason that a multi-variable control that contemplates the interaction that occurs among the valves just mentioned, departing from a single variable design. The robust control H{infinity} has the following characteristics that allow it to be applied to the steam turbine process: the design can be made to have two poles in the origin, with which a good follow up to references of incline type is obtained; it allows the uncertainty handling, with which good results in everything are expected an entire operation interval; and it allows the design of multi-variable controllers, with which the existing interaction between the valves of control and bypass is considered. It is very difficult to be able to make tests with the real process, due to the cost and risks that it implies, nevertheless, the developments achieved in the areas

  6. Thermoeconomic optimization of subcooled and superheated vapor compression refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Selbas, Resat; Kizilkan, OEnder; Sencan, Arzu [Technical Education Faculty, Department of Mechanical Education, Sueleyman Demirel University, Isparta 32260 (Turkey)

    2006-09-15

    An exergy-based thermoeconomic optimization application is applied to a subcooled and superheated vapor compression refrigeration system. The advantage of using the exergy method of thermoeconomic optimization is that various elements of the system - i.e., condenser, evaporator, subcooling and superheating heat exchangers - can be optimized on their own. The application consists of determining the optimum heat exchanger areas with the corresponding optimum subcooling and superheating temperatures. A cost function is specified for the optimum conditions. All calculations are made for three refrigerants: R22, R134a, and R407c. Thermodynamic properties of refrigerants are formulated using the Artificial Neural Network methodology. (author)

  7. Integrating a SOFC Plant with a Steam Turbine Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Scappin, Fabio

    2009-01-01

    A Solid Oxide Fuel Cell (SOFC) is integrated with a Steam Turbine (ST) cycle. Different hybrid configurations are studied. The fuel for the plants is assumed to be natural gas (NG). Since the NG cannot be sent to the anode side of the SOFC directly, a desulfurization reactor is used to remove....... The off-gases after the burner are now used to generate steam in a Heat Recovery Steam Generator (HRSG). The generated steam is expanded in a ST to produce additional power. Different systems layouts are considered. Cyclic efficiencies up to 67% are achieved which is considerably higher than...

  8. The 700{sup o}C steam turbine power plant status of development and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Edelmann, Heiner; Effert, Martin; Wieghardt, Kai; Kirchner, Holger

    2007-08-15

    This paper appraises the current development status of the 700{sup o}C steam power plant under consideration of process optimisation as well as design aspects of the steam turbine and steam generator. The results for a compact arrangement of the steam turbine and steam generator are also presented. Based on a cycle analysis, a net efficiency between 49.3% and 51.4% can be achieved with the 700{sup o}C steam power plant depending on the implementation and based on an inland plant site. No competing development activities for the 700{sup o}C steam power plant are known from the USA or Japan.

  9. Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle Cardenas, B.; Lugo Leyte, R. [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G. [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

    1998-12-31

    This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

  10. Reliability design method for steam turbine blades

    Institute of Scientific and Technical Information of China (English)

    Jinyuan SHI

    2008-01-01

    Based on theories of probability and statistics, and taking static stresses, dynamic stresses, endurance strength, safety ratios, vibration frequencies and exciting force frequencies of blades as random variables, a reliabil-ity design method for steam turbine blades is presented. The purport and calculation method for blade reliability are expounded. The distribution parameters of random variables are determined after analysis and numerical cal-culation of test data. The fatigue strength and the vibra-tion design reliability of turbine blades are determined with the aid of a probabilistic design method and by inter-ference models for stress distribution and strength distri-bution. Some blade reliability design calculation formulas for a dynamic stress design method, a safety ratio design method for fatigue strength, and a vibration reliability design method for the first and second types of tuned blades and a packet of blades on a disk connected closely, are given together with some practical examples. With these methods, the design reliability of steam turbine blades can be guaranteed in the design stage. This research may provide some scientific basis for reliability design of steam turbine blades.

  11. Rotor thermal stress monitoring in steam turbines

    Science.gov (United States)

    Antonín, Bouberle; Jan, Jakl; Jindřich, Liška

    2015-11-01

    One of the issues of steam turbines diagnostics is monitoring of rotor thermal stress that arises from nonuniform temperature field. The effort of steam turbine operator is to operate steam turbine in such conditions, that rotor thermal stress doesn't exceed the specified limits. If rotor thermal stress limits are exceeded for a long time during machine operation, the rotor fatigue life is shortened and this may lead to unexpected machine failure. Thermal stress plays important role during turbine cold startup, when occur the most significant differences of temperatures through rotor cross section. The temperature field can't be measured directly in the entire rotor cross section and standardly the temperature is measured by thermocouple mounted in stator part. From this reason method for numerical solution of partial differential equation of heat propagation through rotor cross section must be combined with method for calculation of temperature on rotor surface. In the first part of this article, the application of finite volume method for calculation of rotor thermal stress is described. The second part of article deals with optimal trend generation of thermal flux, that could be used for optimal machine loading.

  12. Thermoelastic steam turbine rotor control based on neural network

    Science.gov (United States)

    Rzadkowski, Romuald; Dominiczak, Krzysztof; Radulski, Wojciech; Szczepanik, R.

    2015-12-01

    Considered here are Nonlinear Auto-Regressive neural networks with eXogenous inputs (NARX) as a mathematical model of a steam turbine rotor for controlling steam turbine stress on-line. In order to obtain neural networks that locate critical stress and temperature points in the steam turbine during transient states, an FE rotor model was built. This model was used to train the neural networks on the basis of steam turbine transient operating data. The training included nonlinearity related to steam turbine expansion, heat exchange and rotor material properties during transients. Simultaneous neural networks are algorithms which can be implemented on PLC controllers. This allows for the application neural networks to control steam turbine stress in industrial power plants.

  13. Optimum sizing of steam turbines for concentrated solar power plants

    OpenAIRE

    Andreas Poullikkas, Constantinos Rouvas, Ioannis Hadjipaschalis, George Kourtis

    2012-01-01

    In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP) plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software...

  14. Steam turbines and operation of steam turbines 2010. Proceedings; Dampfturbinen und Dampfturbinenbetrieb 2010. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Within the VGB conference an 30th June to 1st July, 2010 in Luebeck (Federal Republic of Germany) the following lectures were held: (1) Application of rifled tubes in power plant heat exchangers (Andreas Grahl); (2) Improved efficiency and potential savings at the 'cool end' through tube cleaning and cooling water filtration (Wolfgang Czolkoss); (3) Material and process improvements in condenser tubing (Pascal Gerard); (4) Automatic eddy current testing of longitudinally welded austentic and titanium tubes for condensers and other heat exchanger (Werner Hannig); (5) Major steam turbine losses: causes, repair measures, recommissioning (Stefan Thumm); (6) Damage on industrial steam turbines (Hans-Guenter Busch); (7) Proper design of turbine draining systems (Ralph Semme); (8) VDMA - Contribution to functional safety of turbomachinery - Required risk reduction by safety functions for steam turbines (Bernhard Wuest); (9) Functional safety by MAN turbo on the example of SIL3 safety loop overspeed detection (Holger Buschmann); (10) Boiler feed pump monitoring, diagnostic and controlling loop (Sohail Ahmed); (11) Experimental investigation to the radial adjustment of brush seals for steam turbines (Heiko Schwarz); (12) The revised VGB guidelines for condenser tubes from copper alloys, stainless steels and titanium (Frank-Udo Leidich); (13) Modernization of HP and LP turbines in coal-fired power plant Bergkamen (Roland Sommer); (14) Mega-components made of cast steel for power plant technology (Reinhold Hanus); (15) Quality monitoring of steam turbine sets for new construction projects of the Vattenfall Europe Generation AG (Marco Rediess); (16) Weld repair of a cracked LP rotor (Andreas Nowi); (17) Steam turbines and CO{sub 2} sequestration (Juergen Klebes); (18) Advanced filter element construction for alleviating electrostatic discharge effects in turbine lubricating systems (John K. Duchowski).

  15. Exergo-Economic Fuel-Impact Analysis for Steam Turbines Sections in Power Plants

    Directory of Open Access Journals (Sweden)

    Javier Royo

    2003-09-01

    Full Text Available In this paper exergoeconomic fuel-impact models for steam turbines in power plants are proposed. They are applied to calculate the impact on the steam cycle when malfunctions are occurring during the operation of steam turbine sections. Concepts such as the exergetic consumption and the dissipation temperature are used to understand the proposed fuel-impact analysis. In order to validate these fuel-impact methods, well-known procedures, to simulate on- and off-design conditions of a steam power cycle, are used as references. Three different methods a ASME PTC-6, b existing fuel-impact formula, and c proposed exergoeconomic Fuel–Impact formulation, are compared with respect to the simulator results. The proposed models allow evaluating fuel-impact cost with more accurate results than conventional procedures. An example of a 158 MW conventional power plant is presented herein. The malfunction costs occurring in the steam turbines are inferred from the results. One perspective of this analysis is to establish an on-line monitoring system into power plants that permits to opportunely detect steam turbine malfunctions, without simulators.

  16. A high-temperature gas-and-steam turbine plant operating on combined fuel

    Science.gov (United States)

    Klimenko, A. V.; Milman, O. O.; Shifrin, B. A.

    2015-11-01

    A high-temperature gas-steam turbine plant (GSTP) for ultrasupercritical steam conditions is proposed based on an analysis of prospects for the development of power engineering around the world and in Russia up to 2040. The performance indicators of a GSTP using steam from a coal-fired boiler with a temperature of 560-620°C with its superheating to 1000-1500°C by firing natural gas with oxygen in a mixingtype steam superheater are analyzed. The thermal process circuit and design of a GSTP for a capacity of 25 MW with the high- and intermediate-pressure high-temperature parts with the total efficiency equal to 51.7% and the natural gas utilization efficiency equal to 64-68% are developed. The principles of designing and the design arrangement of a 300 MW GSTP are developed. The effect of economic parameters (the level and ratio of prices for solid fuel and gas, and capital investments) on the net cost of electric energy is determined. The net cost of electric energy produced by the GSTP is lower than that produced by modern combined-cycle power plants in a wide variation range of these parameters. The components of a high-temperature GSTP the development of which determines the main features of such installations are pointed out: a chamber for combusting natural gas and oxygen in a mixture with steam, a vacuum device for condensing steam with a high content of nondensables, and a control system. The possibility of using domestically available gas turbine technologies for developing the GSTP's intermediate-pressure high-temperature part is pointed out. In regard of its environmental characteristics, the GSTP is more advantageous as compared with modern condensing power plants: it allows a flow of concentrated carbon dioxide to be obtained at its outlet, which can be reclaimed; in addition, this plant requires half as much consumption of fresh water.

  17. Materials for advanced ultrasupercritical steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Purgert, Robert [Energy Industries Of Ohio Inc., Independence, OH (United States); Shingledecker, John [Energy Industries Of Ohio Inc., Independence, OH (United States); Saha, Deepak [Energy Industries Of Ohio Inc., Independence, OH (United States); Thangirala, Mani [Energy Industries Of Ohio Inc., Independence, OH (United States); Booras, George [Energy Industries Of Ohio Inc., Independence, OH (United States); Powers, John [Energy Industries Of Ohio Inc., Independence, OH (United States); Riley, Colin [Energy Industries Of Ohio Inc., Independence, OH (United States); Hendrix, Howard [Energy Industries Of Ohio Inc., Independence, OH (United States)

    2015-12-01

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have sponsored a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired power plants capable of operating at much higher efficiencies than the current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of advanced ultrasupercritical (A-USC) steam conditions. A limiting factor in this can be the materials of construction for boilers and for steam turbines. The overall project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760°C (1400°F)/35MPa (5000 psi). This final technical report covers the research completed by the General Electric Company (GE) and Electric Power Research Institute (EPRI), with support from Oak Ridge National Laboratory (ORNL) and the National Energy Technology Laboratory (NETL) – Albany Research Center, to develop the A-USC steam turbine materials technology to meet the overall project goals. Specifically, this report summarizes the industrial scale-up and materials property database development for non-welded rotors (disc forgings), buckets (blades), bolting, castings (needed for casing and valve bodies), casting weld repair, and casting to pipe welding. Additionally, the report provides an engineering and economic assessment of an A-USC power plant without and with partial carbon capture and storage. This research project successfully demonstrated the materials technology at a sufficient scale and with corresponding materials property data to enable the design of an A-USC steam turbine. The key accomplishments included the development of a triple-melt and forged Haynes 282 disc for bolted rotor construction, long-term property development for Nimonic 105 for blading and bolting, successful scale-up of Haynes 282 and Nimonic 263 castings using

  18. A detection of the coarse water droplets in steam turbines

    Directory of Open Access Journals (Sweden)

    Bartoš Ondřej

    2014-03-01

    Full Text Available The aim of this paper is to introduce a novel method for the detection of coarse water droplets in a low pressure part of steam turbines. The photogrammetry method has been applied for the measurement of coarse droplets in the low-pressure part of a steam turbine. A new probe based on this measurement technique was developed and tested in the laboratory and in a steam turbine in the Počerady power-plant. The probe was equipped with state-of-the-art instrumentation. The paper contains results from laboratory tests and the first preliminary measurements in a steam turbine. Possible applications of this method have been examined.

  19. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  20. Wet steam wetness measurement in a 10 MW steam turbine

    OpenAIRE

    Kolovratník Michal; Bartoš Ondřej

    2014-01-01

    The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  1. Optimum sizing of steam turbines for concentrated solar power plants

    Directory of Open Access Journals (Sweden)

    Andreas Poullikkas, Constantinos Rouvas, Ioannis Hadjipaschalis, George Kourtis

    2012-01-01

    Full Text Available In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software tool. The results indicate that the estimated efficiency and the expected specific capital cost of the power block are very important criteria in choosing the best steam turbine size of a CSP plant. For capacity sizes of 10kWe up to 50MWe, the steam turbine efficiency increases and the steam turbine expected specific capital cost of the power block decreases at a high rate, whereas for larger sizes they remain almost constant. Thus, there is significant efficiency gains to be realized and large cost savings in increasing the turbine size up to 50MWe. Finally, although the cost of electricity of a CSP plant with capacities greater than 1MWe is significantly reduced to less than 1US$/kWh, currently such technology can only become economically viable through supporting schemes.

  2. Optimum sizing of steam turbines for concentrated solar power plants

    Energy Technology Data Exchange (ETDEWEB)

    Poullikkas, Andreas; Rouvas, Constantinos; Hadjipaschalis, Ioannis; Kourtis, Gorge [Electricity Authority of Cyprus, P.O. Box 24506, 1399 Nicosia (Cyprus)

    2012-07-01

    In this work, a selection of the optimum steam turbine type and size for integration in concentrated solar power (CSP) plants is carried out. In particular, the optimum steam turbine input and output interfaces for a range of CSP plant capacity sizes are identified. Also, efficiency and electricity unit cost curves for various steam turbine capacities are estimated by using a combination of the Steam Pro software module of the Thermoflow Suite 18 package and the IPP v2.1 optimization software tool. The results indicate that the estimated efficiency and the expected specific capital cost of the power block are very important criteria in choosing the best steam turbine size of a CSP plant. For capacity sizes of 10kWe up to 50MWe, the steam turbine efficiency increases and the steam turbine expected specific capital cost of the power block decreases at a high rate, whereas for larger sizes they remain almost constant. Thus, there is significant efficiency gains to be realized and large cost savings in increasing the turbine size up to 50MWe. Finally, although the cost of electricity of a CSP plant with capacities greater than 1MWe is significantly reduced to less than 1US$/kWh, currently such technology can only become economically viable through supporting schemes.

  3. The Life Assessment of Steam Turbine Rotors for Fossil Power Plants

    Science.gov (United States)

    Chang, Sungho; Song, Geewook; Kim, Bumshin; Hyun, Jungseb; Ha, Jeongsoo

    The operational mode of thermal power plants has been changed from base load to duty cycle. From the changeover, fossil power plants cannot avoid frequent thermal transient states, for example, start up and stop, which results in thermal fatigue damage at the heavy section components. The rotor is the highest capital cost component in a steam turbine and requires long outage for replacing with a new one. For an optimized power plant operational life, inspection management of the rotor is necessary. It is known in general that the start-up and shutdown operations greatly affect the steam turbine life. The start-up operational condition is especially severe because of the rapid temperature and rotational speed increase, which causes damage and reduction of life of the main components life of the steam turbine. The start-up stress of a rotor which is directly related to life is composed of thermal and rotational stresses. The thermal stress is due to the variation of steam flow temperature and rotational stress is due to the rotational speed of the turbine. In this paper, the analysis method for the start-up stress of a rotor is proposed, which considers simultaneously temperature and rotational speed transition, and includes a case study regarding a 500MW fossil power plant steam turbine rotor. Also, the method of quantitative damage estimation for fatigue-creep damage to operational conditions, is described. The method can be applied to find weak points for fatigue-creep damage. Using the method, total life consumption can be obtained, and can be also be used for determining future operational modes and life extension of old fossil power units.

  4. S209FA燃气一蒸汽联合循环Dl l型汽轮机调节阀的电液转换控制%ElectrO-hydrauUc Conversion Control of Dll Steam Turbine Control Valve in S209FA Gas-Steam Combined Cycle Unit

    Institute of Scientific and Technical Information of China (English)

    陈元锁

    2010-01-01

    Introduce the steam path of D11 Steam Turbine in S209FA Gas—Steam Combined Cycle Unit.Explain the control algorithm of the main steam,reheat steam and LP steam control valves.Describe the electro-hydraulic control principle and implementation process of control valves.%对S209FA燃气一蒸汽联合循环DIl型汽轮机的蒸汽流程进行说明;对主蒸汽、再热蒸汽以及低压补汽调节阀的控制计算进行讲解,并对这些调节阀的电液控制原理和实现过程进行叙述。

  5. Advanced HP/IP Blading Technologies for the Design of Highly Efficient Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    Mathias Deckers; Ernst Wilhelm Pfitzinger; Wilfried Ulm

    2004-01-01

    This paper presents Siemens' latest improvements in steam turbine blading and blading design tools. The technology offers improved performance and highest efficiencies for a wide range of steam turbine applications.

  6. Advanced HP/IP Blading Technologies for the Design of Highly Efficient Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    MathiasDeckers; ErnstWilhelmPfitzinger; WilfriedUlm

    2004-01-01

    This paper presents Siemens’ latest improvements in steam turbine blading and blading design tools. The technology offers improved performance and highest efficiencies for a wide range of steam turbine applications.

  7. Grey Theory Based Vibration Prediction for Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    LIANG Lei; SU Leitao; FENG Yongxin; JIANG Dongxiang

    2012-01-01

    The Mechanism of grey prediction method and its application advantages in safety prediction were described.This method was used to predict the vibration amplitude within the coming 6 hours for a steam turbine.Moreover,the prediction results were examined using correlation degree and posterior error.Results indicated that,this grey prediction method had small posterior error and got a grade Ⅰ accuracy.We can foreknow the variation trend of vibration amplitude of the steam turbine through this method,so as to take timely countermeasures.Therefore,the operation safety of the power unit was improved.

  8. Recent trends in repair and refurbishing of steam turbine components

    Indian Academy of Sciences (India)

    A K Bhaduri; S K Albert; S K Ray; P Rodriguez

    2003-06-01

    The repair and refurbishing of steam generator components is discussed from the perspective of repair welding philosophy including applicable codes and regulations. Some case histories of repair welding of steam generator components are discussed with special emphasis on details of repair welding of cracked steam turbine blades and shrouds in some of the commercial nuclear power plants using procedures developed.

  9. Water droplet erosion of stainless steel steam turbine blades

    Science.gov (United States)

    Kirols, H. S.; Kevorkov, D.; Uihlein, A.; Medraj, M.

    2017-08-01

    Steam turbine blades are highly subjected to water droplet erosion (WDE) caused by high energy impingement of liquid water droplets. However, most of the published research on this wear phenomenon is performed on laboratory test rigs, instead of addressing WDE of actual steam turbine blades. In this work, the progression of erosion on the surface of ex-service low pressure steam turbine blades was investigated using scanning electron microscopy. The erosion appearance and mechanisms are compared with laboratory test rig results that are carried out using a rotating disk rig according to ASTM G73 standard. Initial and advanced erosion stages could be observed on the steam turbine blades. Similar to the WDE rig coupons, initial pits and cracks were preceded by blade surface roughening through the formation of asperities and depressions. In addition, it was also observed that the twist angle of the turbine blade around its diagonal, is an important parameter that influences its WDE. Twist angle has an effect on: impact angle, erosion appearance, impact speed, and the affected area. Furthermore, according to the current experimental results, multi-ray rig erosion test results are considered the closest simulation to the actual ex-service blade in terms of damage appearance.

  10. Recent Life Assessment Technology for Existing Steam Turbines

    Science.gov (United States)

    Saito, Kiyoshi; Sakuma, Akira; Fukuda, Masataka

    A large and growing portion of electricity is produced by aging thermal power plants. Although excellent, high quality materials such as CrMoV steel and 12% Cr steel, etc. are used for the steam turbines, various forms of metallurgical degradation, due to creep and fatigue, etc. affect the parts and components during long-term operation at high temperature. Extending the life of steam turbines and ensuring high reliability requires life assessment technology, scheduled repairing, conversion, modification and upgrading of components in order to provide a stable power supply. As the high temperature parts and components of aged steam turbines are mainly metallurgically damaged by creep, fatigue and the interaction of both, life assessment combined with analytical and nondestructive methods is essential for realizing strategic plant life extension. We have developed a life assessment technology that takes material degradation into consideration, and have applied the procedure to more than 650 units and 2500 components since 1983. A rotor bore replication device was developed in 1989 for the purpose of nondestructive observation of creep voids and supporting the validity of life prediction results. This paper describes the technical features and applied experience of recent life assessment technology for existing high temperature steam turbines.

  11. Modeling and Optimization of the Steam Turbine Network of an Ethylene Plant

    Institute of Scientific and Technical Information of China (English)

    LI Zeqiu; ZHAO Liang; DU Wenli; QIAN Feng

    2013-01-01

    In this paper,we developed a hybrid model for the steam turbines of a utility system,which combines an improved neural network model with the thermodynamic model.Then,a nonlinear programming (NLP) model of the steam turbine network is formulated by utilizing the developed steam turbine models to minimize the total steam cost for the whole steam turbine network.Finally,this model is applied to optimize the steam turbine network of an ethylene plant.The obtained results demonstrate that this hybrid model can accurately estimate and evaluate the performance of steam turbines,and the significant cost savings can be made by optimizing the steam turbine network operation at no capital cost.

  12. Flow studies in a wet steam turbine

    Science.gov (United States)

    Evans, D. H.; Pouchot, W. D.

    1974-01-01

    The design and test results of a four stage wet vapor turbine operating with slightly superheated inlet steam and expanding to 10% exit moisture are presented. High speed movies at 3000 frames per second of liquid movement on the pressure side and along the trailing edge of the last stator blade are discussed along with back lighted photographs of moisture drops as they were torn from the stator blade trailing edge. Movies at lower framing rates were also taken of the exit of the last rotating blade and the casing moisture removal slot located in line with the rotor blade shroud. Also moisture removal data are presented of casing slot removal at the exit of the third and fourth rotor blades and for slots located in the trailing edge of the last stator blade. Finally, the degradation of turbine thermodynamic performance due to condensation formation and movement is discussed.

  13. Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor = Thermodynamic analysis of a power cycle such as SOFC fuel cell and steam turbine

    Directory of Open Access Journals (Sweden)

    Alexandre Sordi

    2006-01-01

    Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia dosistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é atecnologia mais eficiente.The objective of this article was to analyze the thermodynamic of ahybrid system, SOFC / ST (SOFC fuel cell and ST steam turbine. The fuel for the analysis was the gas methane (biogas produced through the anaerobic digestion of the organic residues. The utilized methodology was the energy balance of the system SOFC / ST,considering the internal reforming of methane in the fuel cell, in a way to obtain its electric effectiveness. The result was compared to a conventional combined cycle of gas turbine and steam turbine (GT / ST for powers between 10 MW and 30 MW. The efficiency of the hybrid system SOFC / ST varied from 61 to 66% in relation to the lower heating value of methane; and the efficiency of the combined cycle GT / ST varied from 41 to 55% within the same power interval. For distributed generation, the SOFC fuel cell is the most efficienttechnology.

  14. Cooling performance of grid-sheets for highly loaded ultra-supercritical steam turbines

    Institute of Scientific and Technical Information of China (English)

    Dieter BOHN; Robert KREWINKEL; Shuqing TIAN

    2009-01-01

    In order to increase efficiency and achieve a further CO2-reduction, the next generation of power plant turbines will have steam turbine inlet temperatures that are considerably higher than the current ones. The high pressure steam turbine inlet temperature is expected to be increased up to approximately 700℃ with a live steam pressure of 30 MPa. The elevated steam parameters in the high and intermediate pressure turbines can be encountered with Ni-base alloys, but this is a costly alternative associated with many manufacturing difficulties. Colla-borative research centre 561 "Thermally Highly Loaded,Porous and Cooled Multi-Layer Systems for Combined Cycle Power Plants" at RWTH Aachen University proposes cooling the highly loaded turbines instead, as this would necessitate the application of far less Ni-base alloys.To protect the thermally highly loaded components, a sandwich material consisting of two thin face sheets and a core made from a woven wire mesh is used to cover the walls of the steam turbine casing. The cooling steam is led through the woven wire mesh between the two face sheets to achieve a cooling effect. The wire mesh provides the grid-sheet with structural rigidity under varying operating conditions.In the present work, the cooling performance of the grid-sheets will be investigated applying the conjugate heat transfer method to ultra-supercritical live and cooling steam conditions for a section of the cooling structure. The behaviour of the flow and the heat transfer in the grid-sheet will be analyzed in detail using a parameter variation. The numerical results should give a first prediction of the cooling performance under future operating conditions.

  15. COMPUTATIONAL FLUID DYNAMIC ANALYSIS OF INTERMEDIATE PRESSURE STEAM TURBINE

    OpenAIRE

    C RAJESH BABU

    2013-01-01

    a steam prime mover with rotary motion of the driving element, or rotor, and continuous operation. It converts the thermal energy of steam into mechanical work. The steam flow proceeds through directing devices and impinges on curved blades mounted along the periphery of the rotor. By exerting a force on the blades, the steam flow causes the rotor to rotate. Unlike the reciprocating steam engine, the steam turbine makes use of the kinetic rather than the potential energy of steam. The perform...

  16. Fuzzy Reliability Analysis of the Shaft of a Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Field surveying shows that the failure of the steam turbine's coupling is due to fatigue that is caused by compound stress. Fuzzy mathematics was applied to get the membership function of the fatigue strength rule. A formula of fuzzy reliability of the coupling was derived and a theory of coupling's fuzzy reliability is set up. The calculating method of the fuzzy reliability is explained by an illustrative example.

  17. Generalised pole-placement control of steam turbine speed

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-del-Busto, R. [ITESM, Cuernavaca (Mexico). Div. de Ingenieria y Ciencias; Munoz, J. [ITESM, Xochimilco (Mexico). Div. de Ingenieria y Ciencias

    1996-12-31

    An application of a pole-placement self-tuning predictive control algorithm is developed to regulate speed of a power plant steam turbine model. Two types of system representation (CARMA and CARIMA) are used to test the control algorithm. Simulation results show that when using a CARMA model better results are produced. Two further comparisons are made when using a PI controller and a generalised predictive controller. (author)

  18. Steam turbine stress control using NARX neural network

    Science.gov (United States)

    Dominiczak, Krzysztof; Rzadkowski, Romuald; Radulski, Wojciech

    2015-11-01

    Considered here is concept of steam turbine stress control, which is based on Nonlinear AutoRegressive neural networks with eXogenous inputs. Using NARX neural networks,whichwere trained based on experimentally validated FE model allows to control stresses in protected thickwalled steam turbine element with FE model quality. Additionally NARX neural network, which were trained base on FE model, includes: nonlinearity of steam expansion in turbine steam path during transients, nonlinearity of heat exchange inside the turbine during transients and nonlinearity of material properties during transients. In this article NARX neural networks stress controls is shown as an example of HP rotor of 18K390 turbine. HP part thermodynamic model as well as heat exchange model in vicinity of HP rotor,whichwere used in FE model of the HP rotor and the HP rotor FE model itself were validated based on experimental data for real turbine transient events. In such a way it is ensured that NARX neural network behave as real HP rotor during steam turbine transient events.

  19. A model for liquid film in steam turbine

    Science.gov (United States)

    Simon, Amelie; Marcelet, Meryem; Herard, Jean-Marc; Dorey, Jean-Marc; Lance, Michel

    2015-11-01

    Wetness in steam turbines induces losses and erosion. Drops are created due to the fast expansion of the steam (homogeneous nucleation) and the impurities in the steam (heterogeneous nucleation). The droplets grow and some among them settle on the blade leading to a thin liquid film. This film may then be atomized into coarse water drops which crash on the following blades. The liquid film configuration is a thin film on a curved surface, created by the drop deposit and under high steam friction. In steam turbines, the liquid film is subject to high rotational effect (rotor) and/or to negative gravity. Moreover, due to interfacial instabilities, some drops are torn off from the film. The retained approach is an integral formulation of the Navier-Stokes equation (or shallow water equation) with specific terms. The derivation of these equations requires some closure laws for the convection contributions, the Coriolis terms and for terms related to the additional mass coming from the drops deposit. Once chosen, mathematical and mechanical analyses are performed (hyperbolicity, entropy, galilean and rotational invariance). A two-dimensional code has been developed based on finite volume method to simulate numerically this liquid film model for steam turbines.

  20. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were

  1. Influence of the type of working fluid in the lower cycle and superheated steam parameters in the upper cycle on effectiveness of operation of binary power plant

    Directory of Open Access Journals (Sweden)

    Stachel Aleksander A.

    2015-03-01

    Full Text Available In the paper presented have been the results of the analysis of effectiveness of operation of binary power plant consisting of combined two Clausius-Rankine cycles, namely the binary cycle with water as a working fluid in the upper cycle and organic substance as a working fluid in the lower cycle, as well as a single fluid component power plant operating also in line with the C-R cycle for superheated steam, with water as a working fluid. The influence of the parameters of superheated steam in the upper cycle has been assessed as well as the type of working fluid in the lower cycle. The results of calculations have been referred to the single-cycle classical steam power plant operating at the same parameters of superheated steam and the same mass flow rate of water circulating in both cycles. On the basis of accomplished analysis it has been shown that the binary power plant shows a greater power with respect to the reference power plant.

  2. Dynamic computer simulation of the Fort St. Vrain steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Conklin, J.C.

    1983-01-01

    A computer simulation is described for the dynamic response of the Fort St. Vrain nuclear reactor regenerative intermediate- and low-pressure steam turbines. The fundamental computer-modeling assumptions for the turbines and feedwater heaters are developed. A turbine heat balance specifying steam and feedwater conditions at a given generator load and the volumes of the feedwater heaters are all that are necessary as descriptive input parameters. Actual plant data for a generator load reduction from 100 to 50% power (which occurred as part of a plant transient on November 9, 1981) are compared with computer-generated predictions, with reasonably good agreement.

  3. Optimization of cold end system of steam turbine

    Institute of Scientific and Technical Information of China (English)

    Bin ZHAO; Ling LIU; Wenbing ZHANG

    2008-01-01

    An optimization of the movement character-istic of the cold end system of the steam turbine was con-ducted from an overall consideration of the condenser and the circulation water pump. An analysis method based on thermodynamics theory that fixes coupling characteristic between the best vacuum and the best circulation dis-charge of water was proposed. The proposed method was applied to the optimized analysis of the operating mode of the cold end system of a 300 MW unit in a power plant.

  4. Study on 300MW Unit Steam Turbine Shift Seal Renovation in Shanghai Steam Turbine Factory%上汽300 MW机组汽封改造初探

    Institute of Scientific and Technical Information of China (English)

    孙海荣; 葛圣杰

    2015-01-01

    Through introduction of steam turbine shift seal renovation in No.9 unit high and middle pressure cylinder at shanghai wujing thermal power plant, the article analyzes working principle, technical characteristics, installation process and renovation implementation of steam turbine shift seal renovation. It shows that steam turbine shift seal renovation could improve steam turbine thermal economy and improve steam turbine operation safety, which could be widely used in same type 300MW units in shanghai steam turbine factory.%通过上海9号机组高中压缸进行的汽轴封改造的介绍,对改造汽封的工作原理、技术特性、安装工艺及改造实施情况进行了比较详尽的分析。指出了汽封改造对提高汽轮机的热经济性和提高汽轮机运行的安全性都有较好的效果,可以广泛的推广到尚在运行的同类型上汽300MW机组的技术改造过程中去。

  5. Investigation of the steam-cooled blade in a steam turbine cascade

    Institute of Scientific and Technical Information of China (English)

    Dieter Bohn; Jing Ren; Karsten Kusterer

    2007-01-01

    With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the coal-fired plants are expected in order to reach the goals set in the Kyoto protocol.It can be achieved by a rise of the process parameters.Currently,live steam pressures and temperatures up to 300 bars and 923 K are planned as the next step.Closed circuit steam cooling of blades and vanes in modern steam turbines is a promising technology in order to establish elevated live steam temperatures in future steam turbine cycles.In this paper,a steam-cooled test vane in a cascade with external hot steam flow is analyzed numerically with the in-house code CHTflow.A parametric analysis aiming to improve the cooling effectiveness is carried out by varying the cooling mass flow ratio.The results from two investigated cases show that the steam cooling technique has a good application potential in the steam turbine.The internal part of the vane is cooled homogeneously in both cases.With the increased cooling mass flow rate,there is a significant improvement of cooling efficiency at the leading edge.The results show that the increased cooling mass flow ratio can enhance the cooling effectiveness at the leading edge.With respect to trailing edge,there is no observable improvement of cooling effectiveness with the increased cooling mass flow.This implies that due to the limited dimension at the trailing edge,the thermal stress cannot be decreased by increasing the cooling mass flow rate.Therefore,impingement-cooling configuration at the trailing edge might be a solution to overcome the critical thermal stress there.It is also observed that the performance of the cooling effective differs on pressure side and suction side.It implicates that the equilibrium of the cooling effectiveness on two sides are influenced by a coupled relationship between cooling mass flow ratio and hole geometry.In future work,optimizing the hole geometry and cooling steam supply conditions might

  6. Boxberg - a new benchmark for high efficiency steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hoffstadt, U.; Klauke, U.; Hinz, H. [Siemens Power Generation (Germany)

    2001-07-01

    One of the primary tasks associated with the development of modern power plant facilities is to improve the economy of operation, while at the same time reducing environmental pollution. In addition to investigations focused on supercritical steam conditions, Siemens Power generation has made enormous efforts to improve the overall efficiency by decreasing the steam flow energy losses of each steam turbine component: optimization of the admission and exhaust geometries; fully three-dimensional blading profiles; reduction of the seal-steam losses; high reliability, availability and safety of operation; optimization of the efficiency/cost-relations. As a result of these efforts the 907 MW power plant Boxberg was handed over to the customer Vereinigte Energiewerke AG recently. With a thermal gross-efficiency of 48,65% the steam turbine represents a milestone for lignite-fired cogeneration units in the history of modern turbine technology. In conjunction with the presentation of the special turbine features and its optimised fluid dynamic components, the results of assembly, commissioning and acceptance testing will be a key issue in the proposed paper. 14 overheads/slides.

  7. Modern technologies for rendering information support to cogeneration steam turbine units in their design and operation stages

    Science.gov (United States)

    Brezgin, V. I.; Brodov, Yu. M.; Chubarov, A. A.; Brezgin, D. V.

    2013-08-01

    Application of modern information technologies in different stages of the lifecycle of cogeneration turbines is considered as one of possible ways for improving their competitiveness. Specific features relating to rendering information support for steam turbine units during the periods of their design and operation, which are the main stages of their life cycle, are presented. Three-dimension modeling, adaptive, and parametric design technologies are applied in the equipment design stages. Information support technologies developed by the authors are applied during the operation stage. Information is integrated by using a product lifecycle management (PLM) system.

  8. Research and development of improved efficiency small steam turbines (IESST). Technical progress report, Phase I, 16 April-31 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Choate, D.M.; Tuttle, A.H.

    1980-01-01

    Product Statistical Bulletins of the National Electrical Manufacturers Association (NEMA) and Turbodyne's shipment records over a 10-y period were researched to determine quantities installed and to define general parameters of design. Engineering studies were conducted to determine the optimum turbine design to meet the defined design parameters. Two conceptual designs plus an added variation of one design were completed together with designs of gearing required to provide speeds compatible with driven equipment speeds. The calculated performance of the recommended design and currently available small steam turbines were compared and a life cycle cost analysis was conducted to determine the economic competitiveness of the new design.

  9. Steam Turbine Materials for Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, R.; Hawk, J.; Schwant, R.; Saha, D.; Totemeier, T.; Goodstine, S.; McNally, M.; Allen, D. B.; Purgert, Robert

    2009-06-30

    The Ultrasupercritical (USC) Steam Turbine Materials Development Program is sponsored and funded by the U.S. Department of Energy and the Ohio Coal Development Office, through grants to Energy Industries of Ohio (EIO), a non-profit organization contracted to manage and direct the project. The program is co-funded by the General Electric Company, Alstom Power, Siemens Power Generation (formerly Siemens Westinghouse), and the Electric Power Research Institute, each organization having subcontracted with EIO and contributing teams of personnel to perform the requisite research. The program is focused on identifying, evaluating, and qualifying advanced alloys for utilization in coal-fired power plants that need to withstand steam turbine operating conditions up to 760°C (1400°F) and 35 MPa (5000 psi). For these conditions, components exposed to the highest temperatures and stresses will need to be constructed from nickel-based alloys with higher elevated temperature strength than the highchromium ferritic steels currently used in today's high-temperature steam turbines. In addition to the strength requirements, these alloys must also be weldable and resistant to environmental effects such as steam oxidation and solid particle erosion. In the present project, candidate materials with the required creep strength at desired temperatures have been identified. Coatings that can resist oxidation and solid particle erosion have also been identified. The ability to perform dissimilar welds between nickel base alloys and ferritic steels have been demonstrated, and the properties of the welds have been evaluated. Results of this three-year study that was completed in 2009 are described in this final report. Additional work is being planned and will commence in 2009. The specific objectives of the future studies will include conducting more detailed evaluations of the weld-ability, mechanical properties and repair-ability of the selected candidate alloys for rotors

  10. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were

  11. An outbreak of acute fever among steam turbine condenser cleaners.

    Science.gov (United States)

    Lauderdale, J F; Johnson, C C

    1983-03-01

    Ten of twelve men who participated in the cleaning of an electric power steam turbine condenser clogged with freshwater sponge experienced an acute febrile illness. Two similar outbreaks have been previously described, one of which has been attributed to the Legionnaires' Disease bacterium. Epidemiologic studies of this case showed a syndrome very similar to the two previously reported episodes. However, the exact etiology for this outbreak has not been identified. Environmental sampling was not initiated until after the cleaning was completed. Subsequent testing did not reveal any likely cause for the outbreak. The delayed onset of symptoms and the nature of the illness pointed to an infectious agent. In the absence of any suitable criteria for employee exposure evaluation, it is suggested that crews cleaning condensers under unusually dirty conditions, especially if eye or respiratory symptoms are reported, should be provided with respiratory protection.

  12. Crack of a first stage blade in a steam turbine

    Directory of Open Access Journals (Sweden)

    M. Nurbanasari

    2014-10-01

    Full Text Available The failure of the first stage blade in a steam turbine of 55 MW was investigated. The blade was made of 17-4 PH stainless steel and has been used for 12 years before failure. The current work aims to find out the main cause of the first stage blade failure. The methods for investigation were metallurgical analysis, chemical composition test, and hardness measurement. The result showed that there was no evidence the blade failure was due to material. The damage found on the blade namely crack on the blade root. Two locations of the crack observed at the blade root, which was at the tang and the fillet, with different failure modes. In general, the damage of the blade was started by the corrosion occurred on the blade root. The crack at the blade root tang was due to corrosion fatigue and the crack occurred at the blade root fillet owing to stress corrosion cracking.

  13. K-65-12.8 condensing steam turbine

    Science.gov (United States)

    Valamin, A. E.; Kultyshev, A. Yu.; Gol'dberg, A. A.; Sakhnin, Yu. A.; Bilan, V. N.; Stepanov, M. Yu.; Polyaeva, E. N.; Shekhter, M. V.; Shibaev, T. L.

    2016-11-01

    A new condensing steam turbine K-65-12.8 is considered, which is the continuation of the development of the steam turbine family of 50-70 MW and the fresh steam pressure of 12.8 MPa, such as twocylinder T-50-12.8 and T-60/65-12.8 turbines. The turbine was developed using the modular design. The design and the main distinctive features of the turbine are described, such as a single two-housing cylinder with the steam flow loop; the extraction from the blading section for the regeneration, the inner needs, and heating; and the unification of some assemblies of serial turbines with shorter time of manufacture. The turbine uses the throttling steam distribution; steam from a boiler is supplied to a turbine through a separate valve block consisting of a central shut-off valve and two side control valves. The blading section of a turbine consists of 23 stages: the left flow contains ten stages installed in the inner housing and the right flow contains 13 stages with diaphragm placed in holders installed in the outer housing. The disks of the first 16 stages are forged together with a rotor, and the disks of the rest stages are mounted. Before the two last stages, the uncontrolled steam extraction is performed for the heating of a plant with the heat output of 38-75 GJ/h. Also, a turbine has five regenerative extraction points for feed water heating and the additional steam extraction to a collector for the inner needs with the consumption of up to 10 t/h. The feasibility parameters of a turbine plant are given. The main solutions for the heat flow diagram and the layout of a turbine plant are presented. The main principles and features of the microprocessor electro hydraulic control and protection system are formulated.

  14. 改造常规汽轮机电站联合循环系统的热力学分析%THERMODYNAMIC ANALYSIS OF COMBINED CYCLE-REPOWERING OF TRADITIONAL STEAM-TURBINE PLANTS

    Institute of Scientific and Technical Information of China (English)

    刘泽龙; 金红光; 蔡睿贤; 蒋洪德; 林汝谋

    2001-01-01

    联合循环系统改造(Combined Cycle-Repowering)是常规燃煤电站更新最科学最有效的方法之一。本文对两种典型的联合循环系统(排气助燃型FF-Repowering和给水加热型FWH- Repowering)进行了热力学系统模拟研究,得到了随燃机汽机功比变化排气助燃型系统效率单调变化以及给水加热型系统效率存在极值点的现象,并发现了一定燃机汽机功比下给水加热型效率大于排气助燃型的特殊规律。通过对联合循环系统改造各种因素的综合分析,揭示了上述特殊规律的热力学机理,澄清了有关研究的误区。该理论研究对采用联合循环系统技术改造常规电站具有指导意义。%Combined Cycle-Repowering is one of the most scientific andeffective way to improve the performance of existing coal based power plant.Two kinds of representative CC-Repowering (feed water heating repowering,full firing repowering) were analyzed and compared in this paper. Aremarkable phenomenon was observed: Efficiency monotonouslychanges with work-ratio in FF-Repowering system; but in FWH-Repoweringsystem, there exists an optimal ratio at which point the efficiency isthe highest. Another phenomenon to be paid attention is that under somework-ratio, the efficiency of FWH-Repowering is higher than that ofFF-Repowering, giving rise to correcting the conventional concept.After synthetic analysis of every aspect, the fundamental of thesephenomenons were revealed. Some valuable instructions for CC-Repoweringcan be drawn from this paper.

  15. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    Directory of Open Access Journals (Sweden)

    Bogomolov Alexander R.

    2016-01-01

    Full Text Available The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  16. THE ANALYSIS FOR THE AIRFLOW EXCITING-VIBRATION FORCE OF CONTROL STAGE OF STEAM TURBINE

    Institute of Scientific and Technical Information of China (English)

    柴山; 张耀明; 马浩; 曲庆文; 赵又群

    2001-01-01

    Based on the hydrodynamics, the airflow exciting-vibration force of control stage of steam turbine is studied by using the momentum theorem. A formulation for calculating the air exciting-vibration force of the control stage of steam turbine is deduced first by using theoretical analysis method and taking all the design factors of vane and nozzles into consideration. Moreover, the exciting-vibration forces in different load cases are discussed respectively.

  17. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    Science.gov (United States)

    Bogomolov, Alexander R.; Temnikova, Elena Yu.

    2016-02-01

    The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  18. Development of Steam Turbine Inlet Control Valve for Supercritical Pressure at Siemens Industrial Turbomachinery AB

    OpenAIRE

    Sors, Felix; Holm, Patrik

    2010-01-01

    The development in the steam turbine business is heading for applications with much higher steam parameters since this enables a raised efficiency. Steam parameters refer to the pressure and the temperature of the steam. The aim of this study was to generate concepts for steam turbine inlet control valves designed for higher pressure and temperature in comparison with the present design. Future steam power plants using solar energy, based on tower technology, request this kind of performance ...

  19. Thermosyphon Method for Cooling the Rotor Blades of High-Temperature Steam Turbines

    OpenAIRE

    Bogomolov Alexander R.; Temnikova Elena Yu.

    2016-01-01

    The design scheme of closed two-phase thermosyphon were suggested that can provide standard thermal operation of blades of high-temperature steam turbine. The method for thermosyphon calculation is developed. The example of thermal calculation was implemented, it showed that to cool the steam turbine blades at their heating by high-temperature steam, the heat can be removed in the rear part of the blades by air with the temperature of about 440°C.

  20. Energy analysis of a combined solid oxide fuel cell with a steam turbine power plant for marine applications

    Science.gov (United States)

    Welaya, Yousri M. A.; Mosleh, M.; Ammar, Nader R.

    2013-12-01

    Strong restrictions on emissions from marine power plants (particularly SO x , NO x ) will probably be adopted in the near future. In this paper, a combined solid oxide fuel cell (SOFC) and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector. The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler. The calculations were performed for two types of tubular and planar SOFCs, each with an output power of 18 MW. This paper includes a detailed energy analysis of the combined system. Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle. In addition, the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated. It has been found that a high overall efficiency approaching 60% may be achieved with an optimum configuration using the SOFC system. The hybrid system would also reduce emissions, fuel consumption, and improve the total system efficiency.

  1. Energy Analysis of a Combined Solid Oxide Fuel Cell with a Steam Turbine Power Plant for Marine Applications

    Institute of Scientific and Technical Information of China (English)

    Yousri M. A. Welaya; M. Mosleh; Nader R. Ammar

    2013-01-01

    Strong restrictions on emissions from marine power plants (particularly SOx, NOx) will probably be adopted in the near future. In this paper, a combined solid oxide fuel cell (SOFC) and steam turbine fuelled by natural gas is proposed as an attractive option to limit the environmental impact of the marine sector. The analyzed variant of the combined cycle includes a SOFC operated with natural gas fuel and a steam turbine with a single-pressure waste heat boiler. The calculations were performed for two types of tubular and planar SOFCs, each with an output power of 18 MW. This paper includes a detailed energy analysis of the combined system. Mass and energy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of the combined cycle. In addition, the effects of using natural gas as a fuel on the fuel cell voltage and performance are investigated. It has been found that a high overall efficiency approaching 60%may be achieved with an optimum configuration using the SOFC system. The hybrid system would also reduce emissions, fuel consumption, and improve the total system efficiency.

  2. Optimization of Design of Steam Turbine Exhaust Conduits

    Directory of Open Access Journals (Sweden)

    A. S. Goldin

    2014-01-01

    Full Text Available Improving effectiveness turbine was and remains a key issue for today. In order to improve the efficiency of the turbine is necessary to reduce losses in the steam turbine exhaust conduit.This paper presents the design optimization exhaust conduit steam turbine K-27-2.9 produced by JSC «KTW» at the design stage. The aims of optimizing the design were: decreasing hydraulic resistance of the conduit, reduction of non-uniformity of the flow at the outlet of the conduit, equalizing steam flow ahead of the condenser tube bundle.The conduit models were made and flows in it were simulated in environment of the Solid Works and its application COSMOS Flo Works.As the initial conduit model was selected exhaust conduit of turbine PT-25/34-3.4 produced by JSC «KTW». Was obtained by the calculated velocity field at the outlet of the conduit. The analysis of the calculation results revealed the necessity of changes to the initial design of the conduit. The changes were accompanied by calculating currents flow in the conduit, and assessed the impact of design changes on the nature of the course. Further transformation of the construction of the conduit was held on the results of these calculations. Construction changes are not touched by the outer geometry of the conduit, and were introduced to meet technological.According to calculation results, conclusions were drawn and selected three versions of the conduit.Given are the research results for the initial conduit model and modified design versions. In order to evaluate the flow degree of irregularity the momentum factor (Bussinesku factor for outlet crosssection of the selected conduit design version. Analysis of the research results made it possible to determine optimum design of the exhaust conduit.Introducing the suggested alterations in the conduit design will result in improvement of heat exchange in the condenser, an increase in reliability of the tube bundle operation, a decrease in noise and

  3. Computer-aided ultrasonic inspection of steam turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H.; Weber, M.; Weiss, M. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    As the output and economic value of power plants increase, the detection and sizing of the type of flaws liable to occur in the rotors of turbines using ultrasonic methods assumes increasing importance. An ultrasonic inspection carried out at considerable expense is expected to bring to light all safety-relevant flaws and to enable their size to be determined so as to permit a fracture-mechanics analysis to assess the reliability of the rotor under all possible stresses arising in operation with a high degree of accuracy. The advanced computer-aided ultrasonic inspection of steam turbine rotors have improved reliability, accuracy and reproducibility of ultrasonic inspection. Further, there has been an improvement in the resolution of resolvable group indications by applying reconstruction and imagine methods. In general, it is also true for the advanced computer-aided ultrasonic inspection methods that, in the case of flaw-affected forgings, automated data acquisition provides a substantial rationalization and a significant documentation of the results for the fracture mechanics assessment compared to manual inspection. (orig.) 8 refs.

  4. Next Generation Engineered Materials for Ultra Supercritical Steam Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Douglas Arrell

    2006-05-31

    To reduce the effect of global warming on our climate, the levels of CO{sub 2} emissions should be reduced. One way to do this is to increase the efficiency of electricity production from fossil fuels. This will in turn reduce the amount of CO{sub 2} emissions for a given power output. Using US practice for efficiency calculations, then a move from a typical US plant running at 37% efficiency to a 760 C /38.5 MPa (1400 F/5580 psi) plant running at 48% efficiency would reduce CO2 emissions by 170kg/MW.hr or 25%. This report presents a literature review and roadmap for the materials development required to produce a 760 C (1400 F) / 38.5MPa (5580 psi) steam turbine without use of cooling steam to reduce the material temperature. The report reviews the materials solutions available for operation in components exposed to temperatures in the range of 600 to 760 C, i.e. above the current range of operating conditions for today's turbines. A roadmap of the timescale and approximate cost for carrying out the required development is also included. The nano-structured austenitic alloy CF8C+ was investigated during the program, and the mechanical behavior of this alloy is presented and discussed as an illustration of the potential benefits available from nano-control of the material structure.

  5. Can dissolved carbon dioxide be considered dangerous to steam turbine material?

    Energy Technology Data Exchange (ETDEWEB)

    Rziha, M. [Siemens KWU, Erlangen (Germany); Aspden, J.D. [Eskom, Chemistry and Auxiliary Plant Engineering, Johannesburg (South Africa); Bellows, J.C. [Westinghouse Power Generation, Orlando, FL (United States); Hein, M. [PreussenElektra Kraftwerke AG and Co. KG, Kraftwerk Staudinger, Grosskrotzenburg (Germany); Huber, S. [DOC-Labor, IHK Technologiefabrik, Karlsruhe (Germany); Maughan, E.V. [Tablar Messtechnik GmbH, Duisburg (Germany); Pflug, H.D.; Zeijseink, A.G.L. [KEMA Power Generation, ET Arnhern (Netherlands); Seipp, H.-G. [ABB Technikdienste and Logistik GmbH, TDL/C, Mannheim (Germany); Svoboda, R. [ABB Power Generation Ltd., Baden (Switzerland); Woost, O. [Solvay Alkali Bernburg GmbH, Bernburg (Germany)

    1999-07-01

    Modern power plants, mainly combined cycles, are operated more and more in a cycling mode due to the liberalisation of the power market. The so called 2-shift operation with one shutdown daily becomes more and more a ''normal operation''. Under these conditions it is unavoidable that steam with increased acid conductivity resulting from air-borne carbon dioxide ingress during shut down, is fed to the steam turbine more frequently when compared to base load units. In addition, the CO{sub 2}-contamination due thermal breakdown of organic matter must be considered as well. The discussion, if CO{sub 2} is harmful to turbine materials, depending on concentration and time of exposure, is still ongoing. A dedicated group of international scientists and power plant chemists has been commissioned under the auspices of the VGB to examine and document the impact of organic matter and dissolved carbon dioxide on materials of construction in the steam-water circuit of power plant. This presentation deals with the progress made to date by the working group on the discussion if CO{sub 2} is to be considered dangerous to turbine materials. (orig.)

  6. Evaluation of Rotordynamic Stability of a Steam Turbine Due to Labyrinth Seal Force

    Science.gov (United States)

    Hirano, Toshio; Sasaki, Takashi; Sakakida, Hitoshi; Uchida, Tatsuro; Tsutsui, Masaji; Ikeda, Kazunori

    This paper describes the evaluation of unstable vibration caused by the seal force, which is known as "Steam Whirl" in a steam turbine. Stability of a steam turbine is evaluated by complex eigenvalue analysis of rotordynamics model considering the dynamics of seals, rotor, bearings and pedestals. A commercial CFD program is employed to estimate the dynamic coefficients of labyrinth seal. The labyrinth seal of a large scales steam turbine is taken as an object of analysis and a 3D model with eccentric rotor is solved to obtain the rotordynamic force components. The rotordynamic force is derived by integrating the pressure on the rotor surface. Evaluation formula is formed from the results of numerical calculation, which is used to predict the dynamic coefficient of each seal in a steam turbine. Then rotordynamics model of total system including seal is constructed and stability is evaluated by complex eigenvalue analysis. This procedure is applied to the design of steam turbines and enables the optimization of the turbine structure considering the efficiency and stability.

  7. SELECTION OF RUSSIAN STEAM TURBINES FOR THE VIETNAMESE COMBINED GASSTEAM PLANT. THE INFLUENCE OF THE EFFICIENCY OF HIGH-PRESSURE CYLINDER OF STEAM TURBINE K-300-240-2 ON THE POWER OF A GAS-STEAM PLANT IN VIETNAM

    Directory of Open Access Journals (Sweden)

    Pham A. H.

    2015-06-01

    Full Text Available The article looks at the current state of energy in Vietnam and the selection of new Russian steam turbines for operation in combined gas-steam plant in Vietnam. The calculated results of thermal performance scheme 3x1 with combined gas-steam plant 1090 MW based on the Russian steam turbines K-330-240-2 and on the steam turbines TS2A40 Mitsubishi (station PhuMy-1, Vietnam. It also looks at the influence of the efficiency of high-pressure cylinders of Russian steam turbine K-330-240-2 on the efficiency and power of a gas-steam plant 3x1 with 1090 MW, increasing the efficiency of high-pressure cylinder of steam turbine through the use of honeycomb seals in flow part

  8. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    Science.gov (United States)

    Kolovratník, Michal; Bartoš, Ondřej

    2016-03-01

    The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  9. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2016-01-01

    Full Text Available The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement opportunity provided lots of new information for the manufacturer and operator of the steam turbine and valuable experimental data for the phase transition modelling in the wet steam flow. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  10. Thermal test of a hydro-steam turbine in a boiler house

    Science.gov (United States)

    Mil'Man, O. O.; Fedorov, V. A.; Karyshev, A. K.; Shevelev, D. V.; Mikheev, A. G.; Burmistrov, S. A.; Akhlebinin, L. A.

    2009-04-01

    The description of the design of GPT-10 reaction-type hydro-steam turbine of 10-kW capacity is presented. A description of the test facility placed in the boiler house of MUP Kalugateploset is also provided. The results of turbine tests obtained with the temperature of the operating water being varied in a range from 90 to 120°C and a condenser pressure of 10-25 kPa are given. Ways to improve the steam turbine (HST) are proposed and the design parameters of a promising HST of 300 kW capacity are shown.

  11. The effort of the steam turbine caused by a flood wave load

    Science.gov (United States)

    Badur, Janusz; Ziolkowski, Pawel; Kornet, Sebastian; Stajnke, Michal; Bryk, Mateusz; Banas, Kamil; Ziolkowski, Piotr

    2017-03-01

    Development of the Thermal-FSI (Fluid Solid Interaction) let to accurate the process of cooling the steam turbine set. It provide to shorter times of maintenance and repairs of the turbine sets. The cooling of the steam turbine which temperature exceeds 500°C can take time of one week. Insulation and housing is taken off when temperature reaches 100°C. In analysis was applied thermal-FSI which takes into account temperature changes between solid material and fluid. In the paper authors propose this way to estimate effort of the turbine structure caused by an intrusion of water into the flow channels.

  12. 2D-simulation of wet steam flow in a steam turbine with spontaneous condensation

    Institute of Scientific and Technical Information of China (English)

    SUN Lan-xin; ZHENG Qun; LIU Shun-long

    2007-01-01

    Removal of condensates from wet steam flow in the last stages of steam turbines significantly promotes stage efficiency and prevents erosion of rotors. In this paper, homogeneous spontaneous condensation in transonic steam flow in the 2-D rotor-tip section of a stage turbine is investigated.Calculated results agree with experimental data reasonably well. On the basis of the above work, a 2-D numerical simulation of wet steam flow in adjacent root sections of a complex steam turbine stage was carried out. Computational results were analyzed and provide insights into effective removal of humidity.

  13. A Novel Method for Measuring the Coarse Water Droplets in Wet Steam Flow in Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    Xiaoshu Cai; Lili Wang; Yongzhi Pan; Xin Ouyan; Jianqi Shen

    2001-01-01

    Some optical probes based on light extinction have been developed to measure wemess dominated with fine droplets in steam turbine. However, coarse water droplets (hereafter referred to as CWD) that are the main cause of erosion of blade and of wetness loss of steam turbine can't be detected by the extinction probes because of its large size. In this paper, a new method - the light fluctuation method is presented that is capable of measuring the size of CWD. A new probe based on this method was developed for measuring the size of CWD as well as its velocity and concentration.

  14. Experimental investigation of the steam wetness in a 1000 MW steam turbine

    OpenAIRE

    Kolovratník Michal; Bartoš Ondřej

    2016-01-01

    The aim of this paper is to introduce the experimental data of the wetness distribution obtained in the year 2015 in front of and behind the last stage of the 1000MW steam turbine in the power plant Temelín. Two different optical probes developed at Czech Technical University were used. For the first time in the Czech Republic pneumatic and optical measurement of the wet steam flow field in front of the last stage of a nuclear power-station steam turbine was provided. This unique measurement ...

  15. Modelling 3D Steam Turbine Flow Using Thermodynamic Properties of Steam Iapws-95

    Directory of Open Access Journals (Sweden)

    Rusanow A.V.

    2016-01-01

    Full Text Available An approach to approximate equations of state for water and steam (IAPWS-95 for the calculation of three-dimensional flows of steam in turbomachinery in a range of operation of the present and future steam turbines is described. Test calculations of three-dimensional viscous flow in an LP steam turbine using various equations of state (perfect gas, Van der Waals equation, equation of state for water and steam IAPWS-95 are made. The comparison of numerical results with experimental data is also presented.

  16. Characteristics Evaluation of a CO2-Caputuring Power Generation System with Reheat Cycle Utilizing Regenerative Oxygen-Combustion Steam-Superheater

    Science.gov (United States)

    Pak, Pyong Sik

    A new CO2-capturing power generation system is proposed that can be easily realized by applying conventional technologies. In the proposed system, the temperature of middle-pressure steam in a thermal power plant is raised by utilizing oxygen-combusting regenerative steam-superheater. The generated CO2 by combusting fuel in the superheater can be easily separated and captured from the exhaust gas at condenser outlet, and is liquefied. The superheated steam is used to drive a steam turbine power generation system. By adopting a high efficient combined cycle power generation system as an example, it has been shown that the proposed system can increase power output by 10.8%, decrease the CO2 emission amount of the total integrated system by 18.6% with power generation efficiency drop of 2.36% compared with the original power plant without CO2-capture, when superheated steam temperature is 750°C

  17. Design of a Test Loop for Performance Testing of Steam Turbines Under a Variety of Operating Conditions

    Science.gov (United States)

    Guerrette, Jonathan

    The steam turbine is one of the most widely used energy conversion devices in the world, providing shaft power for electricity production, chemical processing, and HVAC systems. There are new opportunities in growing renewable and combined cycle applications. End-users are asking for energy efficiency improvements that require manufacturers to renew their experimentally verified design methods. A structured design approach was carried out along three integrated research thrusts. The first two thrusts, Turbine Performance Prediction and Measurement Planning, were carried out with the aim of supporting the theoretical modeling required for the third thrust, System Modeling. The primary use of the steam turbine test loop will be to improve performance prediction techniques. Thus the primary focus of the first thrust was to describe empirical loss correlations found in the literature. For the second thrust, a preliminary review of measurement codes and standards was carried out to determine their impact on overall test loop design. For the third thrust, quasi-steady theoretical models were derived from first principles for the turbine, condenser, pump, boiler, and pipe components using control volume analyses. The theoretical models were implemented in a new open source simulation environment that carries out the calculation process over a range of up-to three turbine model inputs. A parametric study was undertaken with the goal of defining preliminary design specifications for the test loop components. The test loop was simulated across a wide range of steady states for three different turbine blade configurations, each at three different values of the blade row enthalpy-loss coefficient. The parametric study demonstrates full coverage of possible turbine operating conditions. The results of the simulations were analyzed to narrow the required operating range of the test loop to a series of turbine test paths. The final operational envelope yielded a set of test loop

  18. Multi-objective PID Optimization for Speed Control of an Isolated Steam Turbine using Gentic Algorithm

    Directory of Open Access Journals (Sweden)

    Sanjay Kr. Singh

    2014-05-01

    Full Text Available This study focuses on multi-objective optimization of the PID controllers for optimal speed control for an isolated steam turbine. In complex operations, optimal tuning plays an imperative role in maintaining the product quality and process safety. This study focuses on the comparison of the optimal PID tuning using Multi-objective Genetic Algorithm (NSGA-II against normal genetic algorithm and Ziegler Nichols methods for the speed control of an isolated steam turbine. Isolated steam turbine not being connected to the grid; hence is usually used in refineries as steam turbine, where a hydraulic governor is used for the speed control. The PID controller for the system has been designed and implemented using MATLAB and SIMULINK and the results of the design methods have been compared, analysed and conclusions indicates that the significant improvement of results have been obtained by the Multi-Objective GA based optimization of PID as much faster response is obtained as compared to the ordinary GA and Ziegler Nichols method.

  19. Application of new techniques to renovation of 200 MW steam turbine

    Institute of Scientific and Technical Information of China (English)

    陈浮; 宋彦萍; 王仲奇

    2001-01-01

    Presents the new techniques leading to the improvements in aerodynamics of 200MW steam turbine high-pressure cylinder and mid-pressure cylinder, discusses the rearloaded profile and blade bowing, and concludes from numerical simulation and experimental results that the application of rearloaded profile and blade bowing has improved the performance of 200 MW unit.

  20. Increasing reliability of system water heaters for steam-turbine installations at the design stage

    Science.gov (United States)

    Brezgin, V. I.; Brodov, Yu. M.; Brezgin, D. V.

    2015-12-01

    A system for designing water heaters of steam-turbine installations based on uniting standards, reference information, and some numerical procedures with design procedures via wide use of parameterization is considered. The developed design system is based on extensive application of modern information technologies.

  1. Structural and Phase State of Fractured Rotor of High-Pressure Steam Turbine

    Science.gov (United States)

    Smirnov, A. N.; Ababkov, N. V.; Kozlov, E. V.; Koneva, N. A.; Popova, N. A.

    2016-03-01

    The structural and phase state of the metal of a fractured rotor of a steam turbine is studied with the use of modern methods of physical research. The metal is shown to contain gradient structures. The cause of the failure of the rotor is established. The gradient structures are determined by the developed method of acoustic scanning.

  2. Steam turbine governor modeling and parameters testing for power system simulation

    Institute of Scientific and Technical Information of China (English)

    Ying LI; Chufeng PENG; Zenghui YANG

    2009-01-01

    The theoretical modeling, parameters test and model correction for a steam turbine (ST) governor are discussed. A set of ST Governor system model for power system simulation is created based on this research. A power system simulation for an actual power grid accident is conducted using this new model and the comparison between the simulation and actual data show that the results are satisfactory.

  3. The Steam Turbine: Technical Terminology Bulletin. Terminotech, Vol. 2, No. 4.

    Science.gov (United States)

    General Electric Co. of Canada, Ltd., Montreal, Quebec.

    This issue of a bulletin of technological terminology is devoted to the steam turbine. A brief narrative on the subject is presented in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

  4. Nonpneumonic, short-incubation-period Legionellosis (Pontiac fever) in men who cleaned a steam turbine condenser.

    Science.gov (United States)

    Fraser, D W; Deubner, D C; Hill, D L; Gilliam, D K

    1979-08-17

    Pontiac fever affected ten men who had cleaned a steam turbine condenser with compressed air. Previous epidemics of Pontiac fever and Legionnaires' disease--both caused by Legionella Pneumophila (proposed sp. nov.)--involved "airborne spread" from air-conditioning cooling towers or evaporative condensers. Aerosols of contaminated water in heat-rejection systems appear to be important sources of epidemic legionellosis.

  5. 船舶汽轮机优化设计%Optimal Design of Marine Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    刘成洋; 阎昌琪; 王建军

    2012-01-01

    The marine steam turbine is one of the key equipments in marine power plant, and it tends to using high power steam turbine, which makes the steam turbine to be heavier and larger, it causes difficulties to the design and arrangement of the steam turbine, and the marine maneuverability is seriously influenced. Therefore, it is necessary to apply optimization techniques to the design of the steam turbine in order to achieve the minimum weight or volume by means of finding the optimum combination of design parameters. The math model of the marine steam turbine design calculation was established. The sensitivities of condenser pressure, power ratio of HP turbine with LP turbine, and the ratio of diameter with height at the end stage of LP turbine, which influence the weight of the marine steam turbine, were analyzed. The optimal design of the marine steam turbine, aiming at the weight minimization while satisfying the structure and performance constraints, was carried out with the hybrid particle swarm optimization algorithm. The results show that, steam turbine weight is reduced by 3. 13% with the optimization scheme. Finally, the optimization results were analyzed, and the steam turbine optimization design direction was indicated.%船舶汽轮机是船舶动力装置中关键设备之一,且随着汽轮机大功率的发展趋势,其重量体积进一步增加,这给设备的设计安装带来困难,并严重影响船舶的机动性.因此,有必要在汽轮机设计中,应用优化技术寻找设计参数的最优组合,以减小汽轮机的重量或体积.建立船舶汽轮机设计计算数学模型,对其重量受冷凝器压力、高低压缸功率比和低压缸末级径高比影响的敏感性进行分析.以船舶汽轮机重量最小为目标函数,在满足一定的结构及性能约束条件下,利用混合粒子群算法对其进行优化设计.研究结果显示,采用优化方案后,汽轮机重量减小了3.13%.最后对优

  6. Incorporating supercritical steam turbines into molten-salt power tower plants :

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, James Edward; Wolf, Thorsten; Muley, Nishant

    2013-03-01

    Sandia National Laboratories and Siemens Energy, Inc., examined 14 different subcritical and supercritical steam cycles to determine if it is feasible to configure a molten-salt supercritical steam plant that has a capacity in the range of 150 to 200 MWe. The effects of main steam pressure and temperature, final feedwater temperature, and hot salt and cold salt return temperatures were determined on gross and half-net efficiencies. The main steam pressures ranged from 120 bar-a (subcritical) to 260 bar-a (supercritical). Hot salt temperatures of 566 and 600ÀC were evaluated, which resulted in main steam temperatures of 553 and 580ÀC, respectively. Also, the effects of final feedwater temperature (between 260 and 320ÀC) were evaluated, which impacted the cold salt return temperature. The annual energy production and levelized cost of energy (LCOE) were calculated using the System Advisory Model on 165 MWe subcritical plants (baseline and advanced) and the most promising supercritical plants. It was concluded that the supercritical steam plants produced more annual energy than the baseline subcritical steam plant for the same-size heliostat field, receiver, and thermal storage system. Two supercritical steam plants had the highest annual performance and had nearly the same LCOE. Both operated at 230 bar-a main steam pressure. One was designed for a hot salt temperature of 600ÀC and the other 565ÀC. The LCOEs for these plants were about 10% lower than the baseline subcritical plant operating at 120 bar-a main steam pressure and a hot salt temperature of 565ÀC. Based on the results of this study, it appears economically and technically feasible to incorporate supercritical steam turbines in molten-salt power tower plants.

  7. Issues to improve the safety of 18K370 steam turbine operation

    Directory of Open Access Journals (Sweden)

    Bzymek Grzegorz

    2017-01-01

    Full Text Available The paper presents the process of improving the safety and reliability of operation the 18K370 steam turbines Opole Power Plant since the first failure in 2010 [1], up to install the on-line monitoring system [2]. It shows how the units work and how to analyse the contol stage as a critical node in designing the turbine. Selected results of the analysis of the strength of CSD (Computational Solid Dynamic and the nature of the flow in different operating regimes - thanks to CFD (Computational Fluid Dynamic analysis have been included. We have also briefly discussed the way of lifecycle management of individual elements [2,3]. The presented actions could be considered satisfactory, and improve the safety of operating steam turbines of type 18K370.

  8. Some aspects of numerical simulation of control valves for steam turbines

    Directory of Open Access Journals (Sweden)

    Matas Richard

    2012-04-01

    Full Text Available The contribution deals with the numerical simulation of air and steam flow through the model of control valve for steam turbines. Numerical simulations were compared with experimental measurements for the award of the same boundary conditions. Valve characteristics have been computed for individual travel heights and pressure ratios of two variants of seat inflow angle (90° and 60°. Some other aspects are discussed in the article - comparison of the axysymmetric and 3D modelling, influence of the computational domain size, comparison of characteristics for two flow media, experimental model of the valve etc. The mentioned results are important for engineering simulations and also for design of the control valves for steam turbines of the large output.

  9. Heat transfer coefficient of wheel rim of large capacity steam turbines

    Institute of Scientific and Technical Information of China (English)

    Jinyuan SHI; Zhicheng DENG; Yu YANG; Ganwen JUN

    2008-01-01

    A way of calculating the overall equivalent heat transfer coefficient of wheel rims of large capacity steam turbines is presented. The method and formula to calculate the mean forced convection heat-transfer coefficient of the surface of the blade and for the bottom wall of the blade passage, are introduced. The heat transmission from the blade to the rim was simplified by analogy to heat transmission in the fins. A fin heat transfer model was then used to calculate the equivalent heat transfer coefficient of the blade passage. The overall equivalent heat transfer coefficient of the wheel rim was then calculated using a cylindrical surface model. A practical calculation example was presented. The pro-posed method helps determine the heat transfer bound-ary conditions in finite element analyses of temperature and thermal stress fields of steam turbine rotors.

  10. Erosion study of final stage blading of low pressure steam turbines

    Science.gov (United States)

    Dehouve, J.; Nardin, P.; Zeghmati, M.

    1999-04-01

    In order to increase our knowledge of erosion phenomena, the Steam Turbine Groupe (STG) of ALSTOM has been using an erosion test facility in the C.R.T.V. (Centre de Recherche Turbines à Vapeur). This test facility simulates erosion in low pressure steam turbine cylinders in order to compare the erosion resistance of various blade materials (12% chromium steel, titanium alloys, etc.) and their protection (superficial hardening, coatings, etc.). This test facility also allows us to understand the mechanism causing damage at a macroscopic level (impact energy of the droplets and the loss of eroded volume) and at a microscopic level (residual stress and metallurgic analysis) and therefore to determine an evolution law of material surface damage. In this paper, the behaviour of the materials (12% chromium steel and titanium alloys), which has been analysed by image production measurement methods, will be presented according to different impact velocities.

  11. Thermodynamic wetness loss calculation in a steam turbine rotor tip section: nucleating steam flow

    Science.gov (United States)

    Joseph, Joby; Sathyanarayanan, S.; K, Vigney; Prasad, B. V. S. SS; Biswas, D.; Jimbo, T.

    2016-09-01

    Rapid expansion of steam in the last stages of a steam turbine causes condensation. The formation of liquid droplets due to condensation results in wetness losses, which include aerodynamic losses (due to friction between liquid droplets and the vapour), thermodynamic losses (due to irreversible heat addition), and braking losses (due to the impact of liquid droplets on the blade). The thermodynamic loss contributes up to 80% to the wetness losses when the diameter of the droplets formed is less than 1 μm. In this study, the thermodynamic loss in a two-dimensional steam turbine rotor tip section is numerically investigated for various operating and off-design conditions. A pressure based, Eulerian-Eulerian approach is used to model the non-equilibrium condensation process. The entropy change due to condensation is used to compute the thermodynamic losses.

  12. Effects of Inlet Swirl on the Flow in a Steam Turbine Exhaust Hood

    Institute of Scientific and Technical Information of China (English)

    MiroslavStastny; LadislavTajc; 等

    2000-01-01

    The flow in the exhaust hood of a condensing steam turbine depends to a considerable extent on the inlet swirl of the flow which changes in tandem with the volumetric flow of steam through the last stage.This study gives a description of experiments which were carried out on the exhaust hood of a 500MW steam turbine under various conditions,e.g. when there is rated power,when there is an idle run,or when there are various pressures in the condenser,The flow in a model exhaust hood was investigated by means of CFD methods.Computations were performed with the help of the FLUENT5 code which is based on solving the Navier-Stokes equations while taking the RSM and LES models of turbulence into consideration.The results of the computations are in full conformity with the experiments.

  13. Correlation Dimension in Fault Diagnosis of 600 MW Steam Turbine Generator

    Institute of Scientific and Technical Information of China (English)

    YAO Bao-heng; YANG Xia-ju; TONG De-chun; CHEN Zhao-neng

    2005-01-01

    GP algorithm of correlation dimension computation is ameliorated which overcomes the shortage of traditional one. Improved process of GP algorithm takes the influence of temporal correlative pairs of points on correlation dimension into account and promotes the computational efficiency prominently. Iterative SVD method is applied to remove the influence of noise on the result of correlation dimension. The faults of steam flow turbulence and oil film disturbance which occur in 600MW Steam Turbine Generator are analyzed and whose correlation dimensions are computed. More distinct quantitative index than FFT is gained to distinguish two faults and it's of little importance to apply correlation dimension to study the influence of various factors on steam flow turbulence fault for nonexistence of convergent floor in correlation integral curve, which presents a new way to learn the operational function of large capacity steam turbine generator and carry out comprehensive condition monitoring.

  14. Experimental research of flow parameters on the last stage of the steam turbine 1090 MW

    Science.gov (United States)

    Sedlák, Kamil; Hoznedl, Michal; Bednář, Lukáš; Mrózek, Lukáš; Kalista, Robert

    2016-06-01

    This article deals with a brief description of measurement and evaluation of flow parameters at the output from the last stage of the low pressure steam turbine casing for the saturated steam with the nominal power 1090 MW. Measurement was carried out using a seven-hole pneumatic probe traversing along the length of the blade in several peripheral positions under nominal and selected partial modes. The result is knowledge of distribution of the static, dynamic and total pressure along the length of the blade and velocity distribution including their components. This information is the input data for determination of efficiency of the last stage, the loss coefficient of the diffuser and other significant parameters describing efficiency of selected parts of the steam turbine.

  15. Double hidden layer RBF process neural network based online prediction of steam turbine exhaust enthalpy

    Institute of Scientific and Technical Information of China (English)

    GONG Huanchun

    2014-01-01

    In order to diagnose the unit economic performance online,the radial basis function (RBF) process neural network with two hidden layers was introduced to online prediction of steam turbine exhaust enthalpy.Thus,the model reflecting complicated relationship between the steam turbine exhaust enthalpy and the relative operation parameters was established.Moreover,the enthalpy of final stage extraction steam and exhaust from a 300 MW unit turbine was taken as the example to perform the online calculation. The results show that,the average relative error of this method is less than 1%,so the accuracy of this al-gorithm is higher than that of the BP neutral network.Furthermore,this method has advantages of high convergence rate,simple structure and high accuracy.

  16. Diagnostic methods of a bladed disc mode shape evaluation used for shrouded blades in steam turbines

    Science.gov (United States)

    Strnad, Jaromir; Liska, Jindrich

    2015-11-01

    This paper deals with advanced methods for the evaluation of a bladed disc behavior in terms of the wheel vibration and blade service time consumption. These methods are developed as parts of the noncontact vibration monitoring system of the steam turbine shrouded blades. The proposed methods utilize the time-frequency processing (cross spectra) and the method using least squares to analyse the data from the optical and magnetoresistive sensors, which are mounted in the stator radially above the rotor blades. Fundamentally, the blade vibrations are detected during the blade passages under the sensors and the following signal processing, which covers also the proposed methods, leads to the estimation of the blade residual service life. The prototype system implementing above mentioned techniques was installed into the last stage of the new steam turbine (LP part). The methods for bladed disc mode shape evaluation were successfully verified on the signals, which were obtained during the commission operation of the turbine.

  17. Fatigue damage of steam turbine shaft at asynchronous connections of turbine generator to electrical network

    Science.gov (United States)

    Bovsunovsky, A. P.

    2015-07-01

    The investigations of cracks growth in the fractured turbine rotors point out at theirs fatigue nature. The main reason of turbine shafts fatigue damage is theirs periodical startups which are typical for steam turbines. Each startup of a turbine is accompanied by the connection of turbine generator to electrical network. During the connection because of the phase shift between the vector of electromotive force of turbine generator and the vector of supply-line voltage the short-term but powerful reactive shaft torque arises. This torque causes torsional vibrations and fatigue damage of turbine shafts of different intensity. Based on the 3D finite element model of turbine shaft of the steam turbine K-200-130 and the mechanical properties of rotor steel there was estimated the fatigue damage of the shaft at its torsional vibrations arising as a result of connection of turbine generator to electric network.

  18. Steam oxidation resistant coatings for steam turbine components: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Agueero, A.; Garcia de Blas, J.; Muelas, R.; Sanchez, A.; Tsipas, S. [Instituto de Tecnica Aeroespacial, Madrid (Spain). Area de Materiales

    2001-07-01

    The principal objective of the COST Action 522 is to raise the operating temperatures of both gas and steam turbines in order to increase their efficiency to reduce fuel consumption and emissions. Concerning steam turbines, the operating temperature is expected to rise from 550 C to 650 C, and the use of oxidation resistant coatings is being considered for the first time in Europe. In this preliminary work, two deposition techniques have so far been explored: slurry paints and atmospheric plasma spray (APS). Commercially available materials, known to have good oxidation resistance, were selected for both deposition techniques: one aluminium slurry and three alloyed materials for thermal spray: AlFe, FeCrAl and NiAl. The coatings were characterised by SEM-EDS and steam oxidation testing was carried out at 650 C. The preliminary findings show that some of the studied coatings may offer adequate protection. (orig.)

  19. Research on pattern recognition for marine steam turbine rotor axis orbit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; YANG Zhi-da; XIA Hong

    2003-01-01

    The structure,function and recognition method of an axis orbit auto-recognizing system are presented in this paper.In order to make the best use of information of format and dynamic characteristics of marine steam turbine axis orbit,the structure and functions or neural network are applied to this system,which can be used to auto-recognize axis orbit of the system turbine rotor using BP neural network.

  20. Inlet Flux Influence to Aerodynamic Performance of Steam Turbine Vane Cascade

    OpenAIRE

    Feng Zi-Ming; Ding Huanhuan; Li Chunhong; Xu Ping

    2014-01-01

    In order to improve the aerodynamic performance and the performance of off-design working condition, it is necessary to research the inlet flow rate influence to overall performance of steam turbine. This study uses CFD technology to numerical simulation the flow field of nozzle cascades passage at 80, 100, 120% flow rate, respectively. The simulation results indicates that the various flow loss of nozzle have a little change at 100% design working condition, have decreased at 80% design work...

  1. CTU Optical probes for liquid phase detection in the 1000 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2015-01-01

    Full Text Available The aim of this paper is to introduce the measurement capacity of a new generation of CTU’s optical probes to determine the liquid phase distribution in steam turbines and other energy systems. At the same time the paper presents the first part of the results concerning output wetness achieved through the use of experimental research performed with the probes in a new low pressure (LP part of the steam turbine 1000MW in the Temelin nuclear power plant (ETE. Two different probes were used. A small size extinction probe with a diameter of 25mm which was developed for measuring in a wider range of turbines in comparison with the previous generation with a diameter of 50mm. The second probe used was a photogrammetric probe developed to observe the coarse droplets. This probe is still under development and this measurement was focused on verifying the capabilities of the probe. The data processing technique is presented together with yielded examples of the wetness distribution along the last blade of the 1000MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o. (DSP.

  2. Non-contacting shaft seals for gas and steam turbines

    OpenAIRE

    2012-01-01

    Improvements upon current gas turbine sealing technology performance are essential for decreasing specific fuel consumption to meet stringent future efficiency targets. The clearances between rotating and static components of a gas turbine, which need to be sealed, vary over a flight cycle. Hence, a seal which can passively maintain an optimum clearance, whilst preventing contact between itself and the rotor, is extremely desirable. Various configurations of a Rolls Royce (RR) seal concep...

  3. 基于压水堆核电机组等效热降法的改进算法%Improved Algorithm Based on Equivalent Enthalpy Drop Method of Pressurized Water Reactor Nuclear Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    王虎; 齐光才; 李少华; 李常建

    2011-01-01

    由于核电汽轮机抽汽状态点焓值及排汽焓难以准确确定,使得压水堆核电机组常规等效热降法计算结果存在偏差.针对这一问题,提出压水堆核电机组等效热降法的改进算法.对1000MW压水堆核电机组二回路热力系统进行实例计算,结果表明:用等效热降法的改进算法所得的汽轮机实际循环热效率与设计值相比较,误差在允许的范围内.等效热降法的改进算法基于等熵膨胀过程,核电汽轮机抽汽状态点焓值及排汽焓可以准确确定,在实际运用中比常规等效热降法更合理、更准确.%Because it is difficulty to accurately determine the extraction steam turbine enthalpy and the exhaust enthalpy, the calculated result from the conventional equivalent enthalpy drop method of PWR nuclear steam turbine is not accurate. This paper presents the improved algorithm on the equivalent enthalpy drop method of PWR nuclear steam turbine to solve this problem and takes the secondary circuit thermal system calculation of 1000MW PWR as an example. The results show that, comparing with the design value, the error of actual thermal efficiency of the steam turbine cycle obtained by the improved algorithm is within the allowable range. Since the improved method is based on the isentropic expansion process, the extraction steam turbine enthalpy and the exhaust enthalpy can be determined accurately, which is more reasonable and accurate compared to the traditional equivalent enthalpy drop method..

  4. Effect of internal elements of the steam turbine exhaust hood on losses

    Directory of Open Access Journals (Sweden)

    Tajč Ladislav

    2012-04-01

    Full Text Available The document deals with the flow in the exhaust hood of a single flow steam turbine. The effect of the shape of the external case of the hood and the position and dimensions of the internal reinforcements on the energy loss coefficient is evaluated. Using this coefficient, it is possible to determine the gained or lost output in the diffuser and the entire exhaust hood at a known flow and efficiency of the last stage. Flow research in the exhaust hood was performed especially using numeric simulations; some variants were verified experimentally in the aerodynamic wind tunnel.

  5. Laser shock peening of steam turbine blade for enhanced service life

    Indian Academy of Sciences (India)

    R Sundar; B K Pant; Harish Kumar; P Ganesh; D C Nagpure; P Haedoo; Rakesh Kaul; K Ranganathan; K S Bindra; S M Oak; L M Kukreja

    2014-02-01

    Fretting-fatigue is an important factor influencing service life of turbine blades. The present paper describes laser shock peening of potential crack nucleation site in the root region of steam turbine blade for its enhanced service life. The experimental study, performed with an in-house developed 2.5 J/7 ns Nd:YAG laser demonstrated that laser peening introduced a residual surface compressive stress of −260 to −390 MPa. Case depth of laser peened surface layer was found to be more than 900 m.

  6. An experimental study on flowrate and stability for 600MW supercritical steam-turbine control valve

    Institute of Scientific and Technical Information of China (English)

    相晓伟; 毛靖儒; 孙弼

    2007-01-01

    An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D i...

  7. 3D Flow in the Axial—Radial Exhaust Hood of a Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    STASTNYM.,SKODA; KOLARP.,

    1997-01-01

    The computation model of the 3D viscous flow is used for the analysis of the flow conditions in the model of steam turbine exhaust hood,that was in previous time investigated experimentally,The computation method and the obtained results are described.The calculation is concentrated on the finding of the influence of inlet velocity field and on the influence of compressibility of the flow medium.Especially it followed the fluid motion in the outlte vortex and the occurrence of the areas with flow separation.

  8. Analysis of unsteady flow forces acting on the thermowell in a steam turbine control stage

    Science.gov (United States)

    Badur, J.; Kornet, S.; Sławiński, D.; Ziółkowski, P.

    2016-10-01

    In the present paper the phenomenon of unsteady flow forces acting on the thermowell for measuring steam temperature in a steam turbine control stage has been presented. The non-stationarity of fluid acting on the thermowell such as: Strouhal frequency, pressure amplitude, pressure peaks, pressure field, velocity field etc. have been studied analytically and numerically. There have been examined two cases of flow with changing mass flow rate, pressure and temperature in the control stage chamber of a turbine high-pressure cylinder. The problem of entry into resonance by thermowell has been described in the ASME standard PTC19.3 TW-2010 with providing detailed guidelines for thermowell designs.

  9. Inlet Flux Influence to Aerodynamic Performance of Steam Turbine Vane Cascade

    Directory of Open Access Journals (Sweden)

    Feng Zi-Ming

    2014-12-01

    Full Text Available In order to improve the aerodynamic performance and the performance of off-design working condition, it is necessary to research the inlet flow rate influence to overall performance of steam turbine. This study uses CFD technology to numerical simulation the flow field of nozzle cascades passage at 80, 100, 120% flow rate, respectively. The simulation results indicates that the various flow loss of nozzle have a little change at 100% design working condition, have decreased at 80% design working condition and have increased at 120% design working condition.

  10. Crack repair welding by CMT brazing using low melting point filler wire for long-term used steam turbine cases of Cr-Mo-V cast steels

    Energy Technology Data Exchange (ETDEWEB)

    Kadoi, Kota, E-mail: kadoi@hiroshima-u.ac.jp [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Murakami, Aoi; Shinozaki, Kenji; Yamamoto, Motomichi [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Matsumura, Hideo [Chugoku Electric Power Co., 3-9-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2016-06-01

    Surface melting by gas tungsten arc (GTA) welding and overlaying by cold metal transfer (CMT) brazing using low melting point filler wire were investigated to develop a repair process for cracks in worn cast steel of steam turbine cases. Cr-Mo-V cast steel, operated for 188,500 h at 566 °C, was used as the base material. Silver and gold brazing filler wires were used as overlaying materials to decrease the heat input into the base metal and the peak temperature during the welding thermal cycle. Microstructural analysis revealed that the worn cast steel test samples contained ferrite phases with intragranular precipitates of Cr{sub 7}C{sub 3}, Mo{sub 2}C, and CrSi{sub 2} and grain boundary precipitates of Cr{sub 23}C{sub 6} and Mo{sub 2}C. CMT brazing using low melting point filler wire was found to decrease the heat input and peak temperature during the thermal cycle of the process compared with those during GTA surface melting. Thus, the process helped to inhibit the formation of hardened phases such as intermetallics and martensite in the heat affected zone (HAZ). Additionally, in the case of CMT brazing using BAg-8, the change in the hardness of the HAZ was negligible even though other processes such as GTA surface melting cause significant changes. The creep-fatigue properties of weldments produced by CMT brazing with BAg-8 were the highest, and nearly the same as those of the base metal owing to the prevention of hardened phase formation. The number of fracture cycles using GTA surface melting and CMT brazing with BAu-4 was also quite small. Therefore, CMT brazing using low melting point filler wire such as BAg-8 is a promising candidate method for repairing steam turbine cases. However, it is necessary to take alloy segregation during turbine operation into account to design a suitable filler wire for practical use.

  11. Dynamic Response of Rub Caused by a Shedding Annular Component Happening in a Steam Turbine

    Directory of Open Access Journals (Sweden)

    J. M. Chen

    2015-01-01

    Full Text Available Rub caused by a shedding annular component is a severe fault happening in a steam turbine, which could result in a long-term wearing effect on the shaft. The shafting abrasion defects shortened the service life and damaged the unit. To identify the fault in time, the dynamic response of rub caused by a shedding annular component was studied as follows: (I a rotor-bearing model was established based on the structural features of certain steam turbines; node-to-node contact constraint and penalty method were utilized to analyze the impact and friction; (II dynamic response of the rotor-bearing system and the shedding component was simulated with the development of rub after the component was dropping; (III fault features were extracted from the vibration near the bearing position by time-domain and frequency-domain analysis. The results indicate that the shedding annular component would not only rotate pivoting its axis but also revolve around the shaft after a period of time. Under the excitation of the contact force, the peak-peak vibration fluctuates greatly. The frequency spectrum contains two main components, that is, the working rotating frequency and revolving frequency. The same phenomenon was observed from the historical data in the field.

  12. An investigation into failure analysis of interfering part of a steam turbine journal bearing

    Directory of Open Access Journals (Sweden)

    M. Mehdizadeh

    2014-10-01

    Full Text Available Journal bearings as so sensitive parts of steam turbines are very susceptible to failure through different mechanisms of wear, fatigue and crush during service conditions. Failure occurring through these mechanisms lead to turbine completely shut down as a result of interfering in working conditions of bearing different parts. In this research, failed interfered part of a journal bearing related to a 320,000 kW steam turbine was examined. Failure analysis investigations were performed by utilizing of stereographic, optical microscopy, scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDS analysis and hardness test. Surface crush, large amounts of surface cracks, no noticeable changes of failed surface chemical composition and microstructure with significant hardness improvement were the main obtained results. The studies were revealed that the bearing part loosing and inappropriate clearance can produce relative displacements under cyclic gradient loading. This condition was detrimental for the service life of turbine journal bearing via failure through fretting fatigue mechanism.

  13. Prediction of Losses in Flow Through the Last Stage of LP Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    S. Dykas; W. Wróblewski; H. (L)ukowicz; T. Chmielniak

    2007-01-01

    The aim of presented work was the prediction of the losses in the wet steam flow through the last stage of 200MW steam turbine LP part. To this end, three numerical tools were used. The first method was the streamline curvature method (SCM) used on the meridional plane with losses correlations. The next two methods, TASCflow commercial CFD code and an in-house CFD code, based on the solution of the Reynoldsaveraged Navier-Stokes equations (RANS). Application of three independent numerical tools allowed to make the more reliable losses analysis and made possible to compare applied numerical methods with each other. For the flow modeling in the last stage of LP steam turbine the various two-phase flow models were used and compared. The equilibrium model and non-equilibrium models with homogeneous and/or heterogeneous condensation were considered. The boundary conditions at the inlet and outlet from the stage were selected in such way to get the beginning of the homogeneous condensation process in the stator. It corresponded to the part load of the turbine, i. e. 140MW power and pressure in condenser 2.7kPa.

  14. BP neural network based online prediction of steam turbine exhaust dryness

    Institute of Scientific and Technical Information of China (English)

    XIE Danmei; CHEN Chang; XIONG Yangheng; GAO Shang; WANG Chun

    2014-01-01

    In large scale condensing turbine unit,the exhaust status always lies in wet steam area.Due to the lack of effective measuring method,the exhaust dryness of the steam turbine is difficult to obtain di-rectly,which has been the difficult problem in online economic analysis for thermal power units.By taking an N1000-25/600/600 ultra-supercritical steam turbine as an example,the nonlinear mapping ability of BP neural network was used to establish a model which can reflect the relationship between exhaust dryness and unit load and exhaust pressure.After learning and training under some typical conditions,this model was used for exhaust dryness online calculation under full condition.The results show the final error of the training samples and verifying samples were controlled within -0.006 1 and -0.001 0,which satisfies the accuracy requirement for engineering calculation,indicating the established BP neural network can be used in exhaust dryness prediction.

  15. Modeling Creep-Fatigue-Environment Interactions in Steam Turbine Rotor Materials for Advanced Ultra-supercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen [General Electric Global Research, Niskayuna, NY (United States)

    2014-04-01

    The goal of this project is to model creep-fatigue-environment interactions in steam turbine rotor materials for advanced ultra-supercritical (A-USC) coal power Alloy 282 plants, to develop and demonstrate computational algorithms for alloy property predictions, and to determine and model key mechanisms that contribute to the damages caused by creep-fatigue-environment interactions.

  16. Heat flow diagrams with and without a deaerator for steam turbine plants with T-250/300-23.5 turbines

    Science.gov (United States)

    Valamin, A. E.; Kultyshev, A. Yu.; Shibaev, T. L.; Gol'dberg, A. A.; Stepanov, M. Yu.

    2016-11-01

    A T-250/300-240 turbine (currently known as T-250/300-23.5), which is operated at 31 steam turbine plants, is the largest in the world extraction turbine (by the heating extraction load) and one of the largest by the nominal capacity. All steam turbine plants equipped with T-250/300-23.5 turbines of different modifications are operated in large cities of Russia and the neighboring countries covering a significant part of the needs of cities for the electric power and almost fully supplying them with heat power. The design life of a significant part of the operated steam turbine plants of this family is either expired or almost expired. It refers to both the turbine unit (including a turbine and a generator) and the turbine plant equipment. For steam turbine plants equipped with T-250/300-23.5 turbines, which were initially designed and mounted for work with deaerators at electric power stations, the heat flow diagrams with and without a deaerator were compared. The main advantages and disadvantages of each scheme were shown. It was concluded that, for the newly constructed power units with supercritical steam parameters, it is preferable to use the heat flow diagram without a deaerator; for the upgraded blocks, if there are no objective reasons for the removal of a deaerator, it is recommended to keep the existing heat flow diagram of a turbine plant.

  17. Arabelle, the most powerful steam turbines in the world; Arabelle, la plus puissante des turbines a vapeur au monde

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-09-15

    The Arabelle-1 turbine is in the heart of the Alstom nuclear technology. This great power (1000 to 1800 MW) turbine uses the Alstom Power Systems technology of welded rotors (applied to all its gas and steam turbines). (O.M.)

  18. Steam turbine

    OpenAIRE

    Vališ, Petr

    2010-01-01

    Diplomová práce se zabývá návrhem parní turbíny s regulovaným odběrem páry pro spalovnu komunálního odpadu. Nejprve je uvedena historie zařízení využívajících páry jako hybného média, dále následuje popis výpočtového programu, v němž výpočet probíhal. Podstata diplomové práce pak spočívá v termodynamickém návrhu lopatkování turbíny, základním návrhu převodovky včetně kontrolních výpočtů a porovnání jednohřídelového a dvouhřídelového konstrukčního provedení z technickoekonomického hlediska. Po...

  19. Combined heat and power plants with parallel tandem steam turbines; Smaaskalig kraftvaerme med parallellkopplade tandemturbiner

    Energy Technology Data Exchange (ETDEWEB)

    Steinwall, Pontus; Norstroem, Urban; Pettersson, Camilla; Oesterlin, Erik

    2004-12-01

    We investigate the technical and economical conditions for a concept with parallel coupled tandem turbines in small scale combined heat and power plants fired with bio-fuel and waste. Performance and heat production costs at varying electricity prices for the concept with two smaller tandem coupled steam turbines has been compared to the traditional concept with one single multi-staged turbine. Three different types of plants have been investigated: - Bio fuelled CHP plant with thermal capacity of 15 MW{sub th}; - Waste fired CHP plant with thermal capacity of 20 MW{sub th}; - Bio fuelled CHP plant with thermal capacity of 25 MW{sub th}. The simple steam turbines (Curtis turbines) used in the tandem arrangement has an isentropic efficiency of about 49 to 53% compared to the multi-staged steam turbines with isentropic efficiency in the range of 59% to 81%. The lower isentropic efficiency for the single staged turbines is to some extent compensated at partial load when one of the two turbines can be shut down leading to better operational conditions for the one still in operation. For concepts with saturated steam at partial load below 50% the tandem arrangements presents higher electricity efficiency than the conventional single turbine alternative. The difference in annual production of electricity is therefore less than the difference in isentropic efficiency for the two concepts. Production of electricity is between 2% and 42% lower for the tandem arrangements in this study. Investment costs for the turbine island has been calculated for the two turbine concepts and when the costs for turbines, generator, power transmission, condensing system, piping system, buildings, assembling, commissioning and engineering has been added the sum is about the same for the two concepts. For the bio-fuelled plant with thermal capacity of 15 MW{sub th} the turbine island amount to about 10-12 MSEK and about 13-15 MSEK for the waste fired plant with a thermal capacity of 20 MW

  20. Corrosion Analysis of Low Pressure Steam Turbine%某汽轮机低压缸腐蚀分析

    Institute of Scientific and Technical Information of China (English)

    徐洪; 张建国; 杨贤彪

    2011-01-01

    The case of erosion/corrosion damage occurring in a low pressure steam turbine was evaluated. This fossil power unit had been put into operation for nearly twenty years, and the used ion exchange resins for water treatment had never been scrapped. The leaked organism of aged ion exchange resins was decomposed into corrosive irons in the water-steam cycle. The action of enriched corrosion irons in the primary condensate water with the water steam made a severe erosion/corrosion of the low pressure turbine. It is important to detect the contents of corrosion irons and displace aged ion exchange resins in time.%对某汽轮机低压缸的腐蚀一磨蚀案例进行了研究.该火电机组投运近20年,从未对补给水处理系统的离子交换树脂进行过报废处理.老化的树脂产生大量有机溶出物,随补给水进入热力系统,受热分解为乙酸根、硫酸根等腐蚀性离子.这些腐蚀性离子在初凝水中富集使其呈酸性,与湿蒸汽共同冲刷腐蚀低压缸内壁,导致严重腐蚀.采用离子色谱仪监测水汽中腐蚀性离子含量,及时报废老化的离子交换树脂,对预防低压缸腐蚀十分必要.

  1. Diagnostics based on thermodynamic analysis of performance of steam turbines: case histories

    Energy Technology Data Exchange (ETDEWEB)

    Tirone, G.; Arrighi, L.; Bonifacino, L.

    1996-12-31

    The purpose of this paper is to describe some types of failures which have occurred with the ENEL stock of fossil-fuel steam turbines over the last 5--7 years. This paper also presents the corresponding thermodynamic analysis of turbine parameters which permitted failure diagnosis and pre-scheduled opening of the turbine. The examined failures concern: in-service rupture of the bell seal retainer nut between the SH steam inlet sleeves and the inner HP/IP cylinder, on turbines with a main steam inlet system with bell seals; incorrect assembly of pressure seal rings between steam inlet sleeves and the inner cylinder on turbines with a main steam inlet system with pressure seal rings during a scheduled outage; and steam flow path restriction in IP turbine inlet. Thermodynamic failure analysis and the subsequent analysis of turbine damage (mechanical and financial) enabled condition-based maintenance operations to be carried out.

  2. An experimental study on flowrate and stability for 600MW supercritical steam-turbine control valve

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An experimental study on flowrate and stability of a type of control valve of 600MW supercritical steam-turbine was presented by measuring instruments of static, dynamic pressure and vibration in self-designed test rig. The investigation shows that flow coefficient is 30% up more than that of the control valve of GX-1 type used widely in domestic power plants now, as small-medium lifts. If the relative lift (h/D) is less than 20%, the valve can always work steadily in all the pressure ratios. When the h/D is between 20% to 24%, big vibration of valve stem occurs if the pressure ratio is between 0.7 to 0.8. When h/D is more than 25%, relatively great vibration happens in a wide range of pressure ratios of 0.4 to 0.85.

  3. Cogeneration turbine unit with a new T-295/335-23.5 steam turbine

    Science.gov (United States)

    Valamin, A. E.; Kultyshev, A. Yu.; Shibaev, T. L.; Gol'dberg, A. A.; Sakhnin, Yu. A.; Stepanov, M. Yu.; Shekhter, M. V.; Bilan, V. N.; Polyaeva, E. N.

    2016-11-01

    The design, schematics, and arrangement of a T-295/335-23.5 turbine and the basic features of a steam-turbine unit (STU) intended for replacement of STUs with a T-250/300-23.5 turbine with the expired service life and installed in large cities, such as Moscow, St. Petersburg, Kiev, Minsk, and Kharkov, for heat and power generation are considered. The basic solutions for an automatic electrohydraulic control and protection system using high-pressure (HP) technology are described. As the turbine operates in a power unit together with a supercritical boiler and the design turbine service life of 250000 hours must be attained, turbine component construction materials complying with these requirements are listed.

  4. Analysis of Fretting Fatigue Strength of Integral Shroud Blade for Steam Turbine

    Science.gov (United States)

    Kaneko, Yasutomo; Tomii, Masayuki; Ohyama, Hiroharu; Kurimura, Takayuki

    To improve the reliability and the thermal efficiency of LP (Low Pressure) end blades of steam turbine, new standard series of LP end blades have been developed. The new LP end blades are characterized by the ISB (Integral Shroud Blade) structure. In the ISB structure, blades are continuously coupled by blade untwist due to centrifugal force when the blades rotate at high speed. One of the probable failure modes of the ISB structure seems to be fretting fatigue, because the ISB utilizes friction damping between adjacent shrouds and stubs. Therefore, in order to design a blade with high reliability, the design procedure for evaluating the fretting fatigue strength was established by the model test and the nonlinear contact analysis. This paper presents the practical design method for predicting the fretting fatigue strength of the ISB structure, and the some applications are explained.

  5. Flow simulation of a partial-admission steam turbine; Stroemungssimulation einer teilbeaufschlagten Dampfturbine

    Energy Technology Data Exchange (ETDEWEB)

    Kalkkuhl, Tobias J.

    2014-11-21

    This thesis discusses the CFD simulation of the flow in an industrial steam turbine, equipped with a control stage. Due to partial admission, the rotor blades suffer from high cyclic blade loading. Specific losses occur. The circumferential asymmetry of the flow involves high gradients of the flow variables in circumferential direction. At the boundaries, between the admitted and the non-admitted sectors, high velocities appear. The specific flow patterns produce high flow unsteadiness of the rotor resulting in cyclic blade loading. Due to the pressure fluctuations the aerodynamic forces, acting on the rotor blades, are many times higher than the average forces in the admitted sector. The thesis describes the high cyclic blade loading, together with the unsteady and three-dimensional flow patterns inside the control stage and the attenuation in the adjacent turbine stages. Modifications to the geometry within the control stage show severe influence on the dynamics.

  6. Development and Verification of 3000Rpm 48Inch Integral Shroud Blade for Steam Turbine

    Science.gov (United States)

    Kaneko, Yasutomo; Mori, Kazushi; Ohyama, Hiroharu

    The 3000rpm 48inch blade for steam turbine was developed as one of the new standard series of LP end blades. The new LP end blades are characterized by the ISB (Integral Shroud Blade) structure. In the ISB structure, blades are continuously coupled by blade untwist due to centrifugal force when the blades rotate at high speed. Therefore, the number of the resonant vibration modes can be reduced by virtue of the vibration characteristics of the circumferentially continuous blades, and the resonant stress can be decreased due to the additional friction damping generated at shrouds and stubs. In order to develop the 3000rpm 48inch blade, the latest analysis methods to predict the vibration characteristics of the ISB structure were applied, after confirming their validity to the blade design. Moreover, the verification tests such as rotational vibration tests and model turbine tests were carried out in the shop to confirm the reliability of the developed blade. As the final verification test, the field test of the actual steam turbine was carried out in the site during the trial operation, and the vibration stress of the 3000rpm 48inch blade was measured by use of telemetry system. In the field test, the vibratory stress of the blade was measured under various operating conditions for more than one month. This paper first presents the up-to-date design technology applied to the design of the 3000rpm 48inch blade. In the second place, the results of the various verification tests carried out in the shop are presented as well as their procedure. Lastly, the results of the final verification tests of 3000rpm 48inch blade carried out in the site are presented.

  7. Operational diagnostics of thermal state and efficiency of steam turbines of TPP and NPP

    Science.gov (United States)

    Bozhko, V. V.; Kovalenko, A. N.; Lyapunov, V. M.; Khomenok, L. A.

    2016-05-01

    Various ways for solving complex problems of the strength and operating life of steam turbines of TPP and NPP are studied. Diagnostic characters and technical possibilities for their control during the steam turbine operation are determined. It is shown that the effect of various factors on the reliability, maneuverability, and service life of power installations of TPP and NPP is generally determined by the thermal state of steam-electric generating sets. Leading foreign and domestic manufacturers give major attention to the organization of the control of the thermal state of facilities and the development of systems for accounting ("counter") the service life depletion. Zones of high-temperature sites of shafts and disks with maximum parameters of operating environment are determined. A model for on-line computation of thermal stresses with the diagnostic evaluation of the service life depletion (fatigue accumulation) and forecasting of optimum heating conditions for thermostressed turbine units is briefly stated. An example of a program for diagnostics of the quality of the facility operation is given. The program provides the operative control of thermal stresses and the service life depletion in main units of the turbine under various operation conditions, operates in the real-time mode, calculates and represents currents values of thermal stresses in turbine units, and forms and transmits into the industrial control signals on the occurrence of restrictions with respect to thermal stresses and prohibition of an increase or decrease in the vapor temperature and the load in the case of approaching pressures to maximum permissible ones. In the case of stationary operation conditions, the program computed the current efficiency in high (HPC) and mean (MPC) pressure cylinders.

  8. 百万千瓦级核电汽轮发电机组选型%The Selecion of the speed of 1000MW Nuclear Steam Turbine Generator

    Institute of Scientific and Technical Information of China (English)

    王雪松

    2001-01-01

    This paper is to show how to select the speed of 1000MW nuclear steam turbine generator forour country's next nuclear power plants in accordance with the developing trend of the nuclear steam turbine generator abroad as well as a comprehensive analysis and comparison of full speed nuclear steam turbine generator and half speed steam turbine generator at 1000MW.%通过对国外核汽轮发电机组发展趋势的分析和对百万千瓦全转速与半转速机组的综合分析比较,简要阐述广东继岭澳一期电站工程后百万千瓦级核电站汽轮发电机组的选型问题。

  9. Combined Rankin and Organic Rankin Cycles with Screw Expenders

    OpenAIRE

    Tang, Yan

    2014-01-01

    Low pressure saturated steam exists in a lot of industries. The recovery of the energy from the low pressure saturated steam can save tremendous power consumption for those industries. Although the Rankin cycle with a steam turbine can be used to generate the power from the low pressure saturated steam, the isotropic efficiency of the steam turbine is low, the reliability is questionable due to the two phase expansion, and the size is typically large due to the low pressure. This paper presen...

  10. Features of steam turbine cooling by the example of an SKR-100 turbine for supercritical steam parameters

    Science.gov (United States)

    Arkadyev, B. A.

    2015-10-01

    Basic principles of cooling of high-temperature steam turbines and constructive solutions used for development of the world's first cooled steam turbine SKR-100 (R-100-300) are described. Principal differences between the thermodynamic properties of cooling medium in the steam and gas turbines and the preference of making flow passes of cooled cylinders of steam turbines as reactive are shown. Some of its operation results and their conclusions are given. This turbine with a power of 100 MW, initial steam parameters approximately 30 MPa and 650°C, and back pressure 3 MPa was made by a Kharkov turbine plant in 1961 and ran successfully at a Kashira GRES (state district power plant) up to 1979, when it was taken out of use in a still fully operating condition. For comparison, some data on construction features and operation results of the super-high pressure cylinder of steam turbines of American Philo 6 (made by General Electric Co.) and Eddystone 1 (made by Westinghouse Co.) power generating units, which are close to the SKR-100 turbine by design initial steam parameters and the implementation time, are given. The high operational reliability and effectiveness of the cooling system that was used in the super-high pressure cylinder of the SKR-100 turbine of the power-generating unit, which were demonstrated in operation, confirms rightfulness and expediency of principles and constructive solutions laid at its development. As process steam temperatures are increased, the realization of the proposed approach to cooling of multistage turbines makes it possible to limit for large turbine parts the application of new, more expensive high-temperature materials, which are required for making steam boilers, and, in some cases, to do completely away with their utilization.

  11. Estimation of Temperature Influence on Creep Rate of High-Temperature Elements in Steam Turbines and Steam Pipelines

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2011-01-01

    Full Text Available The paper considers a high temperature influence on strength characteristics of steam pipelines and steam turbine parts of high and medium pressure. The charts showing a decisive temperature importance in diffuse creep have been presented in the paper. The paper contains a calculation of steel self-diffusion coefficient. Dependence Dsd = f(t for more accurate assessment of  resource characteristics of the applied steel has been proposed in the paper.

  12. Accurate calibration of steam turbine speed control system and its influence on primary regulation at electric grid

    Energy Technology Data Exchange (ETDEWEB)

    Irrazabal Bohorquez, Washington Orlando; Barbosa, Joao Roberto [Technological Institute of Aeronautics (ITA/CTA), Sao Jose dos Campos, SP (Brazil). Center for Reference on Gas Turbine and Energy], E-mail: barbosa@ita.br

    2010-07-01

    In an interconnected electric system there are two very important parameters: the field voltage and the frequency system. The frequency system is very important for the primary regulation of the electric grid. Each turbomachine actuating as generator interconnected to the grid has an automatic speed regulator to keep the rotational speed and mechanical power of the prime machine operating at the set conditions and stable frequency. The electric grid is a dynamical system and in every moment the power units are exposed to several types of disturbances, which cause unbalance of the mechanical power developed by prime machine and the consumed electric power at the grid. The steam turbine speed control system controls the turbine speed to support the electric grid primary frequency at the same time it controls the frequency of the prime machine. Using a mathematical model for the speed control system, the transfer functions were calculated, as well as the proportionality constants of each element of the steam turbine automatic speed regulator. Among other parameters, the droop characteristic of steam turbine and the dynamic characteristics of the automatic speed regulator elements were calculated. Another important result was the determination of the behavior of the speed control when disturbances occur with the improvement of the calibration precision of the control system. (author)

  13. The Influence of Inlet Asymmetry on Steam Turbine Exhaust Hood Flows.

    Science.gov (United States)

    Burton, Zoe; Hogg, Simon; Ingram, Grant L

    2014-04-01

    It has been widely recognized for some decades that it is essential to accurately represent the strong coupling between the last stage blades (LSB) and the diffuser inlet, in order to correctly capture the flow through the exhaust hoods of steam turbine low pressure cylinders. This applies to any form of simulation of the flow, i.e., numerical or experimental. The exhaust hood flow structure is highly three-dimensional and appropriate coupling will enable the important influence of this asymmetry to be transferred to the rotor. This, however, presents challenges as the calculation size grows rapidly when the full annulus is calculated. The size of the simulation means researchers are constantly searching for methods to reduce the computational effort without compromising solution accuracy. However, this can result in excessive computational demands in numerical simulations. Unsteady full-annulus CFD calculation will remain infeasible for routine design calculations for the foreseeable future. More computationally efficient methods for coupling the unsteady rotor flow to the hood flow are required that bring computational expense within realizable limits while still maintaining sufficient accuracy for meaningful design calculations. Research activity in this area is focused on developing new methods and techniques to improve accuracy and reduce computational expense. A novel approach for coupling the turbine last stage to the exhaust hood employing the nonlinear harmonic (NLH) method is presented in this paper. The generic, IP free, exhaust hood and last stage blade geometries from Burton et al. (2012. "A Generic Low Pressure Exhaust Diffuser for Steam Turbine Research,"Proceedings of the ASME Turbo Expo, Copenhagen, Denmark, Paper No. GT2012-68485) that are representative of modern designs, are used to demonstrate the effectiveness of the method. This is achieved by comparing results obtained with the NLH to those obtained with a more conventional mixing

  14. Estimation of the residual life of steam-turbine condensers based on statistical models

    Science.gov (United States)

    Murmansky, B. E.; Aronson, K. E.; Brodov, Yu. M.

    2015-11-01

    The article presents the results of a study aimed at estimation of the state and prediction of the residual life of steam-turbine condensers on the basis of statistical analysis. The possibility of such evaluation during the operation of steam-turbine plants with accuracy sufficient for practical purposes is demonstrated. It is shown that identification of the operating period, viz., the initial period, the normal operation period, or the period of the lifetime exhaustion, as well as determination of the condenser's operating time at the moment when the failure of an individual tube occurs, is very important for statistical evaluation of the condenser state. Two statistical models are proposed and comparative analysis of the results calculated by these models for the residual life of the condensers at the Reftinskaya SDPP has been performed. The first model can be used when comprehensive information about the condenser's operating time before the tubes have failed is available as well as a priori information—or information based on analysis of the condenser tube metal—that the condenser is in its normal operation period. In this case, the fact of exhaustion of the condenser's lifetime is established by reaching the limit of the failed condenser tubes, which is determined by technical and economic analysis of losses caused by operating the turbine with a reduced heat-exchange surface of the condenser. The distribution function for the operating time of the failed tubes is approximated by a normal distribution. In the cases when no precise information on the condenser tubes' operating time is available at the thermoelectric power plant (TEPP), the second statistical model based on censored samples is proposed for estimation of the condenser state. An expression to assess the confidence interval that determines the significant difference between the distribution functions for complete and censored operating time values has been derived. It is shown that this model

  15. Superheated drop neutron spectrometer

    CERN Document Server

    Das, M; Roy, B; Roy, S C; Das, Mala

    2000-01-01

    Superheated drops are known to detect neutrons through the nucleation caused by the recoil nuclei produced by the interactions of neutrons with the atoms constituting the superheated liquid molecule. A novel method of finding the neutron energy from the temperature dependence response of SDD has been developed. From the equivalence between the dependence of threshold energy for nucleation on temperature of SDD and the dependence of dE/dx of the recoil ions with the energy of the neutron, a new method of finding the neutron energy spectrum of a polychromatic as well as monochromatic neutron source has been developed.

  16. Electrochemical corrosion behavior of steam turbine materials for geothermal power plants in simulated geothermal waters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Haofeng [Shinshu Univ. (Japan). Graduate School; Niu Libin; Oishi, Shuji [Shinshu Univ. (Japan). Faculty of Engineering; Takaku, Hiroshi [Shinshu Univ. (Japan). Faculty of Engineering; Naigai Chemical Products Co. (Japan); Shiokawa, Kunio; Yamashita, Mitsuo; Sakai, Yoshihiro [Fuji Electric Advanced Technology Co., Ltd. (Japan)

    2007-08-15

    In order to evaluate the influence of chloride, sulfate and carbon dioxide in water on the electrochemical corrosion behavior of geothermal steam turbine materials, measurements of the anodic polarization and the pitting corrosion potential were conducted in simulated geothermal waters. The corrosion resistance of all materials tested was lowered by an increasing carbon dioxide content in the simulated geothermal waters. Higher chloride concentrations in the waters induced lower corrosion resistance and also lower pitting corrosion potentials for materials with higher chromium contents, suggesting the corrosion behavior was mainly controlled by the chromium content of the materials. The corrosion resistance of 9CrMoV and 13Cr steels was also influenced by the concentration of sulfate in the water. The improved heat-treated 16Cr-4Ni material for turbine blades showed excellent corrosion resistance. In the presence of sulfate, the corrosion reactions are mitigated due to a decreasing concentration of chloride (due to the presence of sulfate) in corrosion pits. (orig.)

  17. Solid particle erosion of steels and nickel based alloys candidates for USC steam turbine blading

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, Federico; Guardamagna, Cristina; Lorenzoni, Lorenzo [ERSE SpA, Milan (Italy); Robba, Davide [CESI, Milan (Italy)

    2010-07-01

    The main objective of COST536 Action is to develop highly efficient steam power plant with low emissions, from innovative alloy development to validation of component integrity. In this perspective, to improve the operating efficiency, materials capable of withstanding higher operating temperatures are required. For the manufacturing of components for steam power plants with higher efficiency steels and nickel-based alloys with improved oxidation resistance and creep strength at temperature as high as 650 C - 700 C have to be developed. Candidate alloys for manufacturing high pressure steam turbine diaphragms, buckets, radial seals and control valves should exhibit, among other properties, a good resistance at the erosion phenomena induced by hard solid particles. Ferric oxide (magnetite) scales cause SPE by exfoliating from boiler tubes and steam pipes (mainly super-heaters and re-heaters) and being transported within the steam flow to the turbine. In order to comparatively study the erosion behaviour of different materials in relatively short times, an accelerated experimental simulation of the erosion phenomena must be carried out. Among different techniques to induce erosion on material targets, the use of an air jet tester is well recognised to be one of the most valid and reliable. In this work the results of SPE comparative tests performed at high temperatures (550 C, 600 C and 650 C) at different impaction angles on some steels and nickel based alloys samples are reported. (orig.)

  18. Diagnostics based on thermodynamic analysis of performance of steam turbines: Case histories

    Energy Technology Data Exchange (ETDEWEB)

    Tirone, G.; Arrighi, L.; Bonifacino, L.

    1998-07-01

    The purpose of this paper is to describe some types of failures which have occurred with the ENEL stock of fossil-fuel steam turbines over the last 5--7 years. This paper also presents the corresponding thermodynamic analysis of turbine parameters which permitted failure diagnosis and pre-scheduled opening of the turbine. The examined failures concern: (1) in-service rupture of the bell seal retainer nut between a SH steam inlet sleeve and the inner HP/IP cylinder, on turbines with a main steam inlet system with bell seals; (2) incorrect assembly of pressure seal rings between steam inlet sleeves and the inner cylinder on turbines with a main steam inlet system with pressure seal rings during a scheduled outage; (3) steam flow path restriction in IP turbine inlet; (4) steam flow path restriction in 1st HP turbine stage nozzles; and (5) steam flow path restriction in 2nd HP turbine stage vanes. Thermodynamic failure analysis and the subsequent analysis of turbine damage (mechanical and financial) enabled condition-based maintenance operations to be carried out.

  19. Effects of Non-Equilibrium Condensation on Deviation Angle and Performance Losses in Wet Steam Turbines

    Directory of Open Access Journals (Sweden)

    Hamed Bagheri Esfe

    2016-01-01

    Full Text Available In this paper, effects of non-equilibrium condensation on deviation angle and performance losses of wet stages of steam turbines are investigated. The AUSM-van Leer hybrid scheme is used to solve the two-phase turbulent transonic steam flow around a turbine rotor tip section. The dominant solver of the computational domain is the non-diffusive AUSM scheme (1993, while a smooth transition from AUSM in regions with large gradients (e.g. in and around condensation- and aerodynamic-shocks to the diffusive scheme by van Leer (1979 guarantees a robust hybrid scheme throughout the domain. The steam is assumed to obey non-equilibrium thermodynamic model, in which abrupt formation of liquid droplets produces a condensation shock. To validate the results, the experimental data by Bakhtar et al. (1995 has been used. It is observed that as a result of condensation, the aerothermodymics of the flow field changes. For example for supersonic wet case with back pressure Pb=30 kPa, the deviation angle and total pressure loss coefficient change by 65% and 200%, respectively, with respect to that in dry case.

  20. A 400-kWe high-efficiency steam turbine for industrial cogeneration

    Science.gov (United States)

    Leibowitz, H. M.

    1982-01-01

    An advanced state-of-the-art steam turbine-generator developed to serve as the power conversion subsystem for the Department of Energy's Sandia National Laboratories' Solar Total-Energy Project (STEP) is described. The turbine-generator, which is designed to provide 400-kW of net electrical power, represents the largest turbine-generator built specifically for commercial solar-powered cogeneration. The controls for the turbine-generator incorporate a multiple, partial-arc entry to provide efficient off-design performance, as well as an extraction control scheme to permit extraction flow regulation while maintaining 110-spsig pressure. Normal turbine operation is achieved while synchronized to a local utility and in a stand-alone mode. In both cases, the turbine-generator features automatic load control as well as remote start-up and shutdown capability. Tests totaling 200 hours were conducted to confirm the integrity of the turbine's mechanical structure and control function. Performance tests resulted in a measured inlet throttle flow of 8,450 pounds per hour, which was near design conditions.

  1. A high-speed photographic system for flow visualization in a steam turbine

    Science.gov (United States)

    Barna, G. J.

    1973-01-01

    A photographic system was designed to visualize the moisture flow in a steam turbine. Good performance of the system was verified using dry turbine mockups in which an aerosol spray simulated, in a rough way, the moisture flow in the turbine. Borescopes and fiber-optic light tubes were selected as the general instrumentation approach. High speed motion-picture photographs of the liquid flow over the stator blade surfaces were taken using stroboscopic lighting. Good visualization of the liquid flow was obtained. Still photographs of drops in flight were made using short duration flash sources. Drops with diameters as small as 30 micrometers (0.0012 in.) could be resolved. In addition, motion pictures of a spray of water simulating the spray off the rotor blades and shrouds were taken at normal framing rates. Specially constructed light tubes containing small tungsten-halogen lamps were used. Sixteen millimeter photography was used in all cases. Two potential problems resulting from the two-phase turbine flow (attenuation and scattering of light by the fog present and liquid accumulation on the borescope mirrors) were taken into account in the photographic system design but not evaluated experimentally.

  2. The deterministic prediction of damage functions to low pressure steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun; Macdonald, D.D.

    1993-01-01

    Localized corrosion phenomena, including pitting corrosion, stress corrosion cracking, and corrosion fatigue, are the principal causes of corrosion-induced damage in electric power generating facilities and typically result in more than 50% of the unscheduled outages. Prediction of damage, so that repairs and inspections can be made during scheduled outages, could have an enormous impact on the economics of electric power generation. To date, prediction of corrosion damage has been made on the basis of empirical/statistical methods that have proven to be insufficiently robust and accurate to form the basis for the desired inspection/repair protocol. In this paper, we describe a deterministic method for predicting localized corrosion damage. We have used the method to illustrate how pitting corrosion initiates stress corrosion cracking (SCC) for low pressure steam turbine disks downstream of the Wilson line, where a thin condensed liquid layer exists on the steel disk surfaces. Our calculations show that the SCC initiation and propagation are sensitive to the oxygen content of the steam, the environment in the thin liquid condensed layer, and the stresses that the disk experiences in service.

  3. The deterministic prediction of damage functions to low pressure steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun; Macdonald, D.D.

    1993-06-01

    Localized corrosion phenomena, including pitting corrosion, stress corrosion cracking, and corrosion fatigue, are the principal causes of corrosion-induced damage in electric power generating facilities and typically result in more than 50% of the unscheduled outages. Prediction of damage, so that repairs and inspections can be made during scheduled outages, could have an enormous impact on the economics of electric power generation. To date, prediction of corrosion damage has been made on the basis of empirical/statistical methods that have proven to be insufficiently robust and accurate to form the basis for the desired inspection/repair protocol. In this paper, we describe a deterministic method for predicting localized corrosion damage. We have used the method to illustrate how pitting corrosion initiates stress corrosion cracking (SCC) for low pressure steam turbine disks downstream of the Wilson line, where a thin condensed liquid layer exists on the steel disk surfaces. Our calculations show that the SCC initiation and propagation are sensitive to the oxygen content of the steam, the environment in the thin liquid condensed layer, and the stresses that the disk experiences in service.

  4. The deterministic prediction of failure of low pressure steam turbine disks

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun; Macdonald, D.D.

    1993-05-01

    Localized corrosion phenomena, including pitting corrosion, stress corrosion cracking, and corrosion fatigue, are the principal causes of corrosion-induced damage in electric power generating facilities and typically result in more than 50% of the unscheduled outages. Prediction of damage, so that repairs and inspections can be made during scheduled outages, could have an enormous impact on the economics of electric power generation. To date, prediction of corrosion damage has been made on the basis of empirical/statistical methods that have proven to be insufficiently robust and accurate to form the basis for the desired inspection/repair protocol. In this paper, we describe a deterministic method for predicting localized corrosion damage. We have used the method to illustrate how pitting corrosion initiates stress corrosion cracking (SCC) for low pressure steam turbine disks downstream of the Wilson line, where a thin condensed liquid layer exists on the steel disk surfaces. Our calculations show that the SCC initiation and propagation are sensitive to the oxygen content of the steam, the environment in the thin liquid condensed layer, and the stresses that the disk experiences in service.

  5. Static and dynamic analysis of 1 220 mm steel last stage blade for steam turbine

    Directory of Open Access Journals (Sweden)

    Kubín Z.

    2009-06-01

    Full Text Available The 3 000 rpm 1 220 mm blade for a steam turbine was developed with application of new design features. The last stage moving blade is designed with an integral cover, a mid-span tie-boss connection and a fir-tree dovetail. With this configuration the blades are continuously coupled by the blade untwist due to the centrifugal force when the blades rotate at high speed, so that vibration control and increased structural damping are provided. Blade was tuned in order to eigen-frequencies were safely far from possible excitation. Because of connection members, the number of the resonant vibration modes can be reduced by virtue of the vibration characteristics of the circumferentially continuous blades. The last stage airfoil was optimalized from view of minimalization of its centrifugal force. In order to develop the 3 000 rpm 1 220 mm blade, the advanced analysis methods to predict dynamics behavior of the bladed structure were applied. Coupled rotor-blade analysis was also aim of the attention. To validate calculated results the verification measurement such as rotational vibration tests was carried out in the high-speed test rig. Relation of the friction damping of the bladed structure on amount of excitation level was also monitored and evaluated.

  6. A Numerical Study on the Supersonic Steam Ejector Use in Steam Turbine System

    Directory of Open Access Journals (Sweden)

    Lin Cai

    2013-01-01

    Full Text Available Supersonic steam ejector is widely used in steam energy systems such as refrigeration, wood drying equipment, papermaking machine, and steam turbine. In this paper the Computational Fluids Dynamics (CFD method was employed to simulate a supersonic steam ejector, SST k-w turbulence model was adopted, and both real gas model and ideal gas model for fluid property were considered and compared. The mixing chamber angle, throat length, and nozzle exit position (NXP primary pressure and temperature effects on entrainment ratio were investigated. The results show that performance of the ejector is underestimated using ideal gas model, and the entrainment ratio is 20%–40% lower than that when using real gas model. There is an optimum mixing chamber angel and NXP makes the entrainment ratio achieve its maximum; as throat length is decreased within a range, the entrainment ratio remains unchanged. Primary fluid pressure has a critical value, and the entrainment ratio reaches its peak at working critical pressure; when working steam superheat degree increases, the entrainment ratio is increased.

  7. Analysis of experimental characteristics of multistage steam-jet electors of steam turbines

    Science.gov (United States)

    Aronson, K. E.; Ryabchikov, A. Yu.; Brodov, Yu. M.; Brezgin, D. V.; Zhelonkin, N. V.; Murmanskii, I. B.

    2017-02-01

    A series of questions for specification of physical gas dynamics model in flow range of steam-jet unit and ejector computation methodology, as well as functioning peculiarities of intercoolers, was formulated based on analysis of experimental characteristics of multistage team-jet steam turbines. It was established that coefficient defining position of critical cross-section of injected flow depends on characteristics of the "sound tube" zone. Speed of injected flow within this tube may exceed that of sound, and pressure jumps in work-steam decrease at the same time. Characteristics of the "sound tube" define optimal axial sizes of the ejector. According to measurement results, the part of steam condensing in the first-stage coolant constitutes 70-80% of steam amount supplied into coolant and is almost independent of air content in steam. Coolant efficiency depends on steam pressure defined by operation of steam-jet unit of ejector of the next stage after coolant of steam-jet stage, temperature, and condensing water flow. As a rule, steam entering content of steam-air mixture supplied to coolant is overheated with respect to saturation temperature of steam in the mixture. This should be taken into account during coolant computation. Long-term operation causes changes in roughness of walls of the ejector's mixing chamber. The influence of change of wall roughness on ejector characteristic is similar to the influence of reverse pressure of the steam-jet stage. Until some roughness value, injection coefficient of the ejector stage operating in superlimiting regime hardly changed. After reaching critical roughness, the ejector switches to prelimiting operating regime.

  8. Processing of Advanced Cast Alloys for A-USC Steam Turbine Applications

    Science.gov (United States)

    Jablonski, Paul D.; Hawk, Jeffery A.; Cowen, Christopher J.; Maziasz, Philip J.

    2012-02-01

    The high-temperature components within conventional supercritical coal-fired power plants are manufactured from ferritic/martensitic steels. To reduce greenhouse-gas emissions, the efficiency of pulverized coal steam power plants must be increased to as high a temperature and pressure as feasible. The proposed steam temperature in the DOE/NETL Advanced Ultra Supercritical power plant is high enough (760°C) that ferritic/martensitic steels will not work for the majority of high-temperature components in the turbine or for pipes and tubes in the boiler due to temperature limitations of this class of materials. Thus, Ni-based superalloys are being considered for many of these components. Off-the-shelf forged nickel alloys have shown good promise at these temperatures, but further improvements can be made through experimentation within the nominal chemistry range as well as through thermomechanical processing and subsequent heat treatment. However, cast nickel-based superalloys, which possess high strength, creep resistance, and weldability, are typically not available, particularly those with good ductility and toughness that are weldable in thick sections. To address those issues related to thick casting for turbine casings, for example, cast analogs of selected wrought nickel-based superalloys such as alloy 263, Haynes 282, and Nimonic 105 have been produced. Alloy design criteria, melt processing experiences, and heat treatment are discussed with respect to the as-processed and heat-treated microstructures and selected mechanical properties. The discussion concludes with the prospects for full-scale development of a thick section casting for a steam turbine valve chest or rotor casing.

  9. Optimum Tilt Angle of Flow Guide in Steam Turbine Exhaust Hood Considering the Effect of Last Stage Flow Field

    Science.gov (United States)

    CAO, Lihua; LIN, Aqiang; LI, Yong; XIAO, Bin

    2017-07-01

    Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam turbine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal design of its structure without consideration of the wet steam condensing flow and the exhaust hood coupled with the front and rear parts. To better understand the aerodynamic performance influenced by the tilt angle of flow guide inside a diffuser, taking a 600 MW steam turbine as an example, a numerical simulator CFX is adopted to solve compressible three-dimensional (3D) Reynolds time-averaged N-S equations and standard k- ɛ turbulence model. And the exhaust hood flow field influenced by different tilt angles of flow guide is investigated with consideration of the wet steam condensing flow and the exhaust hood coupled with the last stage blades and the condenser throat. The result shows that the total pressure loss coefficient and the static pressure recovery coefficient of exhaust hood change regularly and monotonously with the gradual increase of tilt angle of flow guide. When the tilt angle of flow guide is within the range of 30° to 40°, the static pressure recovery coefficient is in the range of 15.27% to 17.03% and the total pressure loss coefficient drops to approximately 51%, the aerodynamic performance of exhaust hood is significantly improved. And the effective enthalpy drop in steam turbine increases by 0.228% to 0.274%. It is feasible to obtain a reasonable title angle of flow guide by the method of coupling the last stage and the condenser throat to exhaust hood in combination of the wet steam model, which provides a practical guidance to flow guide transformation and optimal design in exhaust hood.

  10. Optimum Tilt Angle of Flow Guide in Steam Turbine Exhaust Hood Considering the Effect of Last Stage Flow Field

    Science.gov (United States)

    CAO, Lihua; LIN, Aqiang; LI, Yong; XIAO, Bin

    2017-03-01

    Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam turbine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal design of its structure without consideration of the wet steam condensing flow and the exhaust hood coupled with the front and rear parts. To better understand the aerodynamic performance influenced by the tilt angle of flow guide inside a diffuser, taking a 600 MW steam turbine as an example, a numerical simulator CFX is adopted to solve compressible three-dimensional (3D) Reynolds time-averaged N-S equations and standard k-ɛ turbulence model. And the exhaust hood flow field influenced by different tilt angles of flow guide is investigated with consideration of the wet steam condensing flow and the exhaust hood coupled with the last stage blades and the condenser throat. The result shows that the total pressure loss coefficient and the static pressure recovery coefficient of exhaust hood change regularly and monotonously with the gradual increase of tilt angle of flow guide. When the tilt angle of flow guide is within the range of 30° to 40°, the static pressure recovery coefficient is in the range of 15.27% to 17.03% and the total pressure loss coefficient drops to approximately 51%, the aerodynamic performance of exhaust hood is significantly improved. And the effective enthalpy drop in steam turbine increases by 0.228% to 0.274%. It is feasible to obtain a reasonable title angle of flow guide by the method of coupling the last stage and the condenser throat to exhaust hood in combination of the wet steam model, which provides a practical guidance to flow guide transformation and optimal design in exhaust hood.

  11. A comparative analysis of 3D flow fields between straight and bowed blades in a steam turbine

    Institute of Scientific and Technical Information of China (English)

    M.HASSANVAND; WANG Zhong-qi 王仲奇; WANG Song-tao 王松涛

    2004-01-01

    A commercial Navier-Stokes flow solver has been employed tor simulating steady subsonic flow characteristics and analyzing the comparative features of flow fields between straight and bowed blades applied to the stator of a high pressure steam turbine. For comparison, we have studied the effects of bowed blades on the wakes of stator trailing edge and horse shoe vortex in the rotor. It was found that the position of wakes for bowed blades is shifted toward the blade suction side. Also, we have discussed and compared the entropy generation and energy loss caused by dissipation mechanism within the boundary layers on the hub and shroud; and temperature gradient in meridional plane.

  12. Development and realization of the concept of an integrated system for the improvement of steam turbine plant reliability

    Science.gov (United States)

    Murmanskii, B. E.

    2015-12-01

    Main works performed when implementing the concept of an integrated approach to the improvement of the steam turbine plant (STP) reliability were stated. The technique of an integrated approach to the collection and processing of data on the STP equipment reliability was presented. This technique is based on the information on damages resulting in equipment failures, damages revealed during the routine equipment maintenance, and on data concerning equipment faults occurred when operating the STP. There is an implementation example for the technique of defining main elements specifying the reliability of a specific unit based on the statistical analysis of STP operating data.

  13. The impact research of control modes in steam turbine control system (digital electric hydraulic to the low-frequency oscillation of grid

    Directory of Open Access Journals (Sweden)

    Yanghai Li

    2016-01-01

    Full Text Available Through the analysis of the control theory for steam turbine, the transfer function of the steam turbine control modes in the parallel operation was obtained. The frequency domain analysis indicated that different control modes of turbine control system have different influence on the damping characteristics of the power system. The comparative analysis shows the direction and the degree of the influence under the different oscillation frequency range. This can provide the theory for the suppression of the low-frequency oscillation from turbine side and has a guiding significance for the stability of power system. The results of simulation tests are consistent with the theoretic analysis.

  14. The online diagnosis of steam turbines; El diagnostico en linea de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. Antonio; Rivera G, Juan J; Cristalinas N, Victor M; Marino L, Carlos A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    To maintain the efficiency values, power and unit thermal consumption of the electrical generation units near the design levels, has been always one of the objectives of the operation and maintenance personnel of the power plants of the Comision Federal de Electricidad (CFE). A way to obtain this objective is through the systematic analysis of the equipment operating conditions and of the diagnosis of the deviations causes of the normal operation way. The Gerencia de Operacion de Maquinaria (Management of Turbo-Machinery) through projects contracted with the Unidad de Investigacion y Desarrollo (Unit of Investigation and Development) of the CFE has made the thermal evaluation of different generation units. These evaluations have allowed to identify which internal components are causing the deviations and to improve the planning of the maintenance activities required to bring back the unit to its best working conditions. In this article the methodology for the online thermal evaluation of the steam turbines and its heat transfer auxiliary equipment is described -water condenser and heaters- and some of the obtained results are also presented. [Spanish] Mantener cercanos a los niveles de diseno los valores de eficiencia, potencia y consumo termico unitario de las unidades de generacion electrica ha sido siempre uno de los objetivos del personal de operacion y mantenimiento de las plantas de la Comision Federal de Electricidad (CFE). Una manera de lograr este objetivo es a traves del analisis sistematico de las condiciones de operacion de los equipos y del diagnostico de las causas de las desviaciones del modo normal de operacion. La Gerencia de Turbomaquinaria a traves de proyectos contratados con la Unidad de Investigacion y Desarrollo de la CFE ha realizado la evaluacion termica de diferentes unidades de generacion. Estas evaluaciones han permitido identificar cuales componentes internos estan provocando las desviaciones y mejorar la planeacion de las actividades

  15. FUNDAMENTALS OF THE THEORY OF VENTILLATION PROCESSES IN THE STEAM TURBINES TPP

    Directory of Open Access Journals (Sweden)

    V. M. Neuimin

    2015-01-01

    Full Text Available  The article proposes the theoretical framework of ventilation processes emerging and going on in the stages of TPP steam turbines during the operating regimes with small-quantity volumetric flow rates in the low-pressure cylinder. The basic theory includes new physicomathematical models for estimating the ventilating capacity losses and ventilation heatings-up of the steam and the air-gas channel of the turbine; search and investigation of the factors causing the increased momental loads on the blade wheels of the finale stages which are likely to lead to destruction of the rotating blades. The paper renders the practical results of utilizing the theoretical framework of ventilation processes.The author obtains a new mathematical relation for high-accuracy assessment of the ventilating capacity losses accounting for all the diversification of parameters defining the level of these losses (it is established that the Coriolis force contributes twice as much to the ventilating capacity losses as the centrifugal force. Seven ordinary formulae obtained on its basis provide a separate stage ventilation-losses immediate evaluation (with rotation blades of the finale stage not unwinding from the turning, with rotation blades of the finale and intermediate stages unwinding from the turning, in the turbine altogether-vapor-evacuated including by readings of the regular instruments located at the connecters of the exhaust part of the lowpressure cylinder.As the cornerstone of the new ventilation heating-up evaluation system the author lays two experimentally established facts: the ventilating capacity losses are practically constant at working steam negligible volumetric flow rates; symmetrical ventilating flows in the blade channel mingle entirely to the moment of their split up at the periphery. This renders possible estimating the complete enthalpy increment of the steam being discharged from a stage in relation to the enthalpy of the steam being

  16. FFT Analysis on Coupling Effect of Axial and Torsional Vibrations in Circular Cross Section Beam of Steam Turbine Generators

    Directory of Open Access Journals (Sweden)

    Xiang Xu

    2013-09-01

    Full Text Available This paper presents a novel method to nonlinearly investigate the dynamics of the coupled axial and torsional vibrations in the circular cross section beam of the steam turbine generator using the FFT analysis. Firstly, the coupled axial and torsional vibrations of a beam are proved by equivalent law of shearing stress and different boundary conditions. Then, a nonlinear mathematical model of the coupled axial and torsional vibrations is established by the Galerkin method. Lastly, the fast Fourier transform (FFT is employed to investigate the coupled effect of the beam vibration. A practical calculation example is calculated numerically and the coupled mechanism of the beam’s axial and torsional vibrations is analyzed in detail. The analysis results show that the frequencies of the coupled response would be existed in some special orders and the coupled response frequencies are smaller than the single vibration. Since for the first time the coupled mechanism of the beam’s axial and torsional vibrations is theoretically analyzed, the findings in this work may provide directive reference for practical engineering problems in design of steam turbine generators.

  17. Niederaussem电站1000MW超临界汽轮机%1000 MW Supercritical Steam Turbine for the Niederaussem Plant

    Institute of Scientific and Technical Information of China (English)

    Wilfried Ulm; Dale Ernette; John Kern; Ralf M. Bell

    2003-01-01

    本文对Niederaussem K电站汽轮机的初始运行情况展开讨论,并对已使用的最新技术进行了详细的论述.%This paper will discuss the details of this latest technology as well as the initial operating experience of the Niederaussem K steam turbine.

  18. Analisis Bahaya dengan Metode Hazop dan Manajemen Risiko pada Steam Turbine PLTU di Unit 5 Pembangkitan Listrik Paiton (PT. YTL Jawa Timur

    Directory of Open Access Journals (Sweden)

    Erna Zulfiana

    2013-09-01

    Full Text Available Steam turbine beroperasi pada temperatur dan tekanan uap yang tinggi sehingga keamanan proses harus dijaga agar tidak terjadi bahaya yang menimbulkan risiko. Untuk analisis dan identifikasi bahaya digunakan metode HAZOP yang selanjutnya melakukan manajemen resiko berupa emergency respon plan berdasarkan bahaya yang mungkin terjadi pada PLTU. Identifikasi bahaya dengan metode HAZOP dilakukan dengan penentuan 4 node pada steam turbine yaitu HP Turbine, IP Turbine, LP Turbine 1 dan LP Turbine 2, penentuan guideword dan deviasi berdasarkan control chart data proses transmitter di setiap node, dan untuk estimasi likelihood berdasarkan nilai MTTF tiap transmitter. ERP pada steam turbine dibuat untuk kejadian kebakaran karena berisiko tinggi dan kemungkinan besar terjadi serta dapat menyebabkan bahaya lain seperti ledakan dsb. Dari penelitian ini diketahui kondisi yang paling berbahaya pada steam turbine adalah kondisi high pressure yang diketahui dari risk matrix pressure trasnmitter pada 4 node yang bernilai high dan ekstrim yang dapat menyebabkan turbin mengalami overspeed. Rekomendasi untuk menanggulangi bahaya tersebut antara lain pemasangan pressure alarm, simulasi automatic turbine test, pemeriksaan turbine overspeed protection serta kalibrasi maupun pengecekan pada pressure trasnmitter tersebut.

  19. Reviews Exhibitions: Collider: Step inside the World's Greatest Experiment Equipment: Hero Steam Turbine Classroom Video: Most of Our Universe is Missing Book: Serving the Reich Book: Breakthrough to CLIL for Physics Book: The Good Research Guide Apps: Popplet Web Watch Apps

    Science.gov (United States)

    2014-03-01

    WE RECOMMEND Collider: step inside the world's greatest experiment A great exhibition at the Science Museum in London Hero Steam Turbine Superb engine model gets up to 2500 rpm Most of Our Universe is Missing BBC video explores the dark truth Serving the Reich Science and morality in Nazi Germany The Good Research Guide A non-specialist book for teachers starting out in education research WORTH A LOOK Breakthrough to CLIL for Physics A book based on a physics curriculum for non-English students WEB WATCH Electric cycles online: patterns of use APPS The virtual laboratory advances personal skills

  20. Thermo-economic study on the implementation of steam turbine concepts for flexible operation on a direct steam generation solar tower power plant

    Science.gov (United States)

    Topel, Monika; Ellakany, Farid; Guédez, Rafael; Genrup, Magnus; Laumert, Björn

    2016-05-01

    Among concentrating solar power technologies, direct steam generation solar tower power plants represent a promising option. These systems eliminate the usage of heat transfer fluids allowing for the power block to be run at greater operating temperatures and therefore further increasing the thermal efficiency of the power cycle. On the other hand, the current state of the art of these systems does not comprise thermal energy storage as there are no currently available and techno-economically feasible storage integration options. This situation makes direct steam generation configurations even more susceptible to the already existing variability of operating conditions due to the fluctuation of the solar supply. In the interest of improving the annual performance and competitiveness of direct steam generation solar tower systems, the present study examines the influence of implementing two flexibility enhancing concepts which control the steam flow to the turbine as a function of the incoming solar irradiation. The proposed concepts were implemented in a reference plant model previously developed by the authors. Then, a multi-objective optimization was carried out in order to understand which configurations of the steam turbine concepts yield reductions of the levelized cost of electricity at a lower investment costs when compared to the reference model. Results show that the implementation of the proposed strategies can enhance the thermo-economic performance of direct steam generation systems by yielding a reduction of up to 9.2% on the levelized cost of electricity, mainly due to allowing 20% increase in the capacity factor, while increasing the investment costs by 7.8%.

  1. Causes of Vacuum Reduction in Medium and Small Steam Turbines and Countermeasures%中小汽轮机真空下降的原因分析及应对措施

    Institute of Scientific and Technical Information of China (English)

    屈云海; 邵永秀

    2014-01-01

    The function of the condenser of steam turbine was analyzed, and the main causes of vacuum reduction in the condenser of medium and small steam turbines were in-vestigated and based on this measures to increase the vacuum degree of the condenser of steam turbine were put forward.%分析了汽轮机凝汽器的作用,研究了导致中小汽轮机凝结器真空下降的主要原因,在此基础上提出了提高汽轮机凝结器真空度的措施。

  2. Fatigue life and damage evolution of martensitic steels for low-pressure steam turbine blades in the VHCF regime; Lebensdauer und Schaedigungsentwicklung martensitischer Staehle fuer Niederdruck-Dampfturbinenschaufeln bei Ermuedungsbeanspruchung im VHCF-Bereich

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Stephan

    2014-07-01

    Low-pressure steam turbine blades are usually made of martensitic steels with Cr contents between 9 and 12%, which combine good corrosion resistance, high mechanical strength and sufficient ductility. The inhomogeneous flow field behind the vanes generates high-frequency oscillations above 1 kHz. In addition, the blades with lengths up to 1.5 m are operated at rotational speeds up to 3000 rpm, resulting in large centrifugal forces leading to the superposition of extremely high mean stresses. Also resonance oscillations during start-up and shutdown cannot be completely excluded. Currently, the components are designed using high safety factors against S-N curves with an assumed asymptotic fatigue limit above 107 load cycles. Nevertheless, fatigue cracks are observed even at high number of cycles, starting from the blade root without pre-damage by erosion or steam droplet impingement. While fatigue failure usually occurs at the surface, fatigue cracks at very high number of cycles (> 108) initiate at oxides or intermetallic inclusions below the surface. This transition between both failure mechanisms in the Very High-Cycle Fatigue (VHCF) regime is in the focus of numerous current research activities, because numbers of cycles above 108 can be attained in a viable period of time using the recently developed high-frequency testing techniques operated at 20 kHz. Also for wind turbines, gas turbines, bearings, springs, etc. VHCF issues become increasingly important. Within this work, the fatigue life and damage behavior of a martensitic Cr-steel during fatigue loading with and without high mean stresses at number of cycles to failure above 108 was analyzed. On the one hand, the studies gave insights into the relation between fatigue life and fatigue damage evolution of the investigated group of high-strength steels in the very high cycle fatigue regime (up to 2·109). In particular, the influence of high mean stresses on the VHCF behavior (fracture origin, crack growth

  3. Influence of chloride and carbon dioxide on general and crevice corrosion of steam turbine materials for geothermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, HaiFeng; Niu, Libin; Oishi, Shuji; Takaku, Hiroshi [Shinshu Univ. (Japan). Faculty of Engineering; Shiokawa, Kunio; Yamashita, Mitsuo [Fuji Electric Advanced Technology Co. Ltd. (Japan); Sakai, Yoshihiro [Fuji Electric Systems Co. Ltd. (Japan)

    2006-09-15

    The influence of chloride and CO{sub 2} on general and crevice corrosion of steam turbine materials for geothermal power plants was investigated in two simulated geothermal waters. The general corrosion rates of the rotor steels with a lower Cr content were accelerated due to the CO{sub 2} in the water, while the corrosion rates of the blade steels with a higher Cr content were controlled mainly by the chloride concentration in the waters. Concerning the crevice corrosion behavior, the galvanic corrosion effects in each of the waters were confirmed for the rotor steels with lower corrosion potentials than those of the blade materials, and almost no difference in corrosion behavior was observed between the two waters tested. Regarding general and crevice corrosion in the two simulated geothermal waters, it was determined that a newly developed rotor material and also an improved heat-treated blade material are promising for actual usage in geothermal power plants. (orig.)

  4. Evaluation of the useful life of steam turbine rotors; Evaluacion de vida util de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero Parra, Antonio; Garcia Illescas, Rafael; Kubiak Szyszka, Janusz [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    This article presents the methodology applied by the Management of Turbomachinery of the Institute of Investigaciones Electricas (IIE), for the evaluation of the remaining useful life of steam turbine rotors in the phase of initiation of fissures. The evaluation of the remaining useful life of turbines, will reveal the real state of health of the rotor and will serve as a base for the future decision making that guarantees their structural integrity. [Spanish] El presentes articulo presenta la metodologia aplicada por la Gerencia de Turbomaquinaria del Instituto de Investigaciones Electricas (IIE), para la evaluacion de la vida util remanente de rotores de turbinas de vapor en la fase de iniciacion de fisuras. La evaluacion de la vida util de turbinas, revelar el estado real de salud del rotor y servira de base para la toma de decisiones futuras que garanticen su integridad estructural.

  5. Technique of optimization of minimum temperature driving forces in the heaters of regeneration system of a steam turbine unit

    Science.gov (United States)

    Shamarokov, A. S.; Zorin, V. M.; Dai, Fam Kuang

    2016-03-01

    At the current stage of development of nuclear power engineering, high demands on nuclear power plants (NPP), including on their economy, are made. In these conditions, improving the quality of NPP means, in particular, the need to reasonably choose the values of numerous managed parameters of technological (heat) scheme. Furthermore, the chosen values should correspond to the economic conditions of NPP operation, which are postponed usually a considerable time interval from the point of time of parameters' choice. The article presents the technique of optimization of controlled parameters of the heat circuit of a steam turbine plant for the future. Its particularity is to obtain the results depending on a complex parameter combining the external economic and operating parameters that are relatively stable under the changing economic environment. The article presents the results of optimization according to this technique of the minimum temperature driving forces in the surface heaters of the heat regeneration system of the steam turbine plant of a K-1200-6.8/50 type. For optimization, the collector-screen heaters of high and low pressure developed at the OAO All-Russia Research and Design Institute of Nuclear Power Machine Building, which, in the authors' opinion, have the certain advantages over other types of heaters, were chosen. The optimality criterion in the task was the change in annual reduced costs for NPP compared to the version accepted as the baseline one. The influence on the decision of the task of independent variables that are not included in the complex parameter was analyzed. An optimization task was decided using the alternating-variable descent method. The obtained values of minimum temperature driving forces can guide the design of new nuclear plants with a heat circuit, similar to that accepted in the considered task.

  6. Estimation of lifespan and economy parameters of steam-turbine power units in thermal power plants using varying regimes

    Science.gov (United States)

    Aminov, R. Z.; Shkret, A. F.; Garievskii, M. V.

    2016-08-01

    The use of potent power units in thermal and nuclear power plants in order to regulate the loads results in intense wear of power generating equipment and reduction in cost efficiency of their operation. We review the methodology of a quantitative assessment of the lifespan and wear of steam-turbine power units and estimate the effect of various operation regimes upon their efficiency. To assess the power units' equipment wear, we suggest using the concept of a turbine's equivalent lifespan. We give calculation formulae and an example of calculation of the lifespan of a steam-turbine power unit for supercritical parameters of steam for different options of its loading. The equivalent lifespan exceeds the turbine's assigned lifespan only provided daily shutdown of the power unit during the night off-peak time. We obtained the engineering and economical indices of the power unit operation for different loading regulation options in daily and weekly diagrams. We proved the change in the prime cost of electric power depending on the operation regimes and annual daily number of unloading (non-use) of the power unit's installed capacity. According to the calculation results, the prime cost of electric power for the assumed initial data varies from 11.3 cents/(kW h) in the basic regime of power unit operation (with an equivalent operation time of 166700 hours) to 15.5 cents/(kW h) in the regime with night and holiday shutdowns. The reduction of using the installed capacity of power unit at varying regimes from 3.5 to 11.9 hours per day can increase the prime cost of energy from 4.2 to 37.4%. Furthermore, repair and maintenance costs grow by 4.5% and by 3 times, respectively, in comparison with the basic regime. These results indicate the need to create special maneuverable equipment for working in the varying section of the electric load diagram.

  7. New low pressure exhaust modules for the MAN steam turbine product line. High performance bladings for highest efficiency levels; Neue Niederdruck-Module fuer die MAN-Dampfturbinenproduktlinie. Hochentwickelte Beschaufelungen fuer hoechste Leistungsdichten und Wirkungsgrade

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, M.A.; Behnke, K.; Klemm, H. [MAN TURBO AG, Oberhausen (Germany)

    2008-07-01

    Currently it can be observed that in the case of generator drives as well as 'mechanical drives' smaller units are demanded with a steam turbine capacity of up to 150 MW and clearly higher efficiencies. MAN TURBO is meeting the challenge through realisation of a comprehensive development project aiming at the extension of the application range of the current steam turbine series.

  8. Offshore Rankine Cycles

    OpenAIRE

    Brandsar, Jo

    2012-01-01

    The title of the thesis - "Offshore Rankine Cycles" - is very general and cover a large range of engineering fields, e.g. thermodynamic cycles (Rankine, ORC, Brayton, Kalina, etc.), mechanical equipment (gas/steam turbine, heat exchangers and additional equipment) and safety concerns (flammable and/or toxic fluids, high temperature and pressures), to name the most important.The thesis try to give a brief overview of all critical points and alternatives, concerning employment of a wa...

  9. BOILER-SUPERHEATED REACTOR

    Science.gov (United States)

    Heckman, T.P.

    1961-05-01

    A nuclear power reactor of the type in which a liquid moderator-coolant is transformed by nuclear heating into a vapor that may be used to drive a turbo- generator is described. The core of this reactor comprises a plurality of freely suspended tubular fuel elements, called fuel element trains, within which nonboiling pressurized liquid moderator-coolant is preheated and sprayed through orifices in the walls of the trains against the outer walls thereof to be converted into vapor. Passage of the vapor ovcr other unwetted portions of the outside of the fuel elements causes the steam to be superheated. The moderatorcoolant within the fuel elements remains in the liqUid state, and that between the fuel elements remains substantiaily in the vapor state. A unique liquid neutron-absorber control system is used. Advantages expected from the reactor design include reduced fuel element failure, increased stability of operation, direct response to power demand, and circulation of a minimum amount of liquid moderatorcoolant. (A.G.W.)

  10. 汽轮机接口设计的分析与研究%Analysis and Research on the Interface Design of Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    张杰

    2015-01-01

    This paper deals with the interface design of nuclear steam turbine, introduced in nuclear power engineering and application interface control manual(ICM)interface design and management related content, clarifies the coal-fired steam turbine technology interface to introduce ICM design superiority, advanced sex and necessity, in the hope of providing reference for future related work.%论述了核电汽轮机的接口设计,介绍了在核电工程中,应用接口控制手册(ICM)进行接口设计和管理的相关内容,阐明了燃煤汽轮机技术接口引进ICM设计的优越性、先进性和必要性,以期为今后相关的工作提供参考。

  11. Materials for Advanced Ultrasupercritical Steam Turbines Task 3: Materials for Non-Welded Rotors, Buckets, and BoltingMaterials for Advanced Ultrasupercritical Steam Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Deepak

    2015-09-15

    The primary objective of the task was to characterize the materials suitable for mechanically coupled rotor, buckets and bolting operating with an inlet temperature of 760°C (1400°F). A previous study DOE-FC26-05NT42442, identified alloys such as Haynes®282®, Nimonic 105, Inconel 740, Waspaloy, Nimonic 263, and Inconel 617 as potential alloys that met the requirements for the necessary operating conditions. Of all the identified materials, Waspaloy has been widely utilized in the aviation industry in the form of disk and other smaller forgings, and sufficient material properties and vendor experience exist, for the design and manufacture of large components. The European program characterizing materials for A-USC conditions are evaluating Nimonic 263 and Inconel 617 for large components. Inconel 740 has been studied extensively as a part of the boiler consortium and is code approved. Therefore, the consortium focused efforts in the development of material properties for Haynes®282® and Nimonic 105 to avoid replicative efforts and provide material choices/trade off during the detailed design of large components. Commercially available Nimonic 105 and Haynes®282® were evaluated for microstructural stability by long term thermal exposure studies. Material properties requisite for design such as tensile, creep / rupture, low cycle fatigue, high cycle fatigue, fatigue crack growth rate, hold-time fatigue, fracture toughness, and stress relaxation are documented in this report. A key requisite for the success of the program was a need demonstrate the successful scale up of the down-selected alloys, to large components. All property evaluations in the past were performed on commercially available bar/billet forms. Components in power plant equipment such as rotors and castings are several orders in magnitude larger and there is a real need to resolve the scalability issue. Nimonic 105 contains high volume fraction y’ [>50%], and hence the alloy is best suited

  12. Influences of attack angle and mach number on aerodynamic characters of typical sections of extra-long blade in a steam turbine

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On super-sonic or trans-sonic planar cascade wind tunnel of free jet intermittent type, wind blowing experiments were performed on the typical sections of stator and rotor blades in the last stage of ultra-ultra-critical steam turbine with extra-long blade of 1200mm. The influences of attack angle and Mach number on the aerodynamic performances of these sections of the blade profiles were verified, and their operating ranges were also specified.

  13. A Novel Hybrid Approach for Numerical Modeling of the Nucleating Flow in Laval Nozzle and Transonic Steam Turbine Blades

    Directory of Open Access Journals (Sweden)

    Edris Yousefi Rad

    2017-08-01

    Full Text Available In the present research, considering the importance of desirable steam turbine design, improvement of numerical modeling of steam two-phase flows in convergent and divergent channels and the blades of transonic steam turbines has been targeted. The first novelty of this research is the innovative use of combined Convective Upstream Pressure Splitting (CUSP and scalar methods to update the flow properties at each calculation point. In other words, each property (density, temperature, pressure and velocity at each calculation point can be computed from either the CUSP or scalar method, depending on the least deviation criterion. For this reason this innovative method is named “hybrid method”. The next novelty of this research is the use of an inverse method alongside the proposed hybrid method to find the amount of the important parameter z in the CUSP method, which is herein referred to as “CUSP’s convergence parameter”. Using a relatively simple computational grid, firstly, five cases with similar conditions to those of the main cases under study in this research with available experimental data were used to obtain the value of z by the Levenberg-Marquardt inverse method. With this innovation, first, an optimum value of z = 2.667 was obtained using the inverse method and then directly used for the main cases considered in the research. Given that the aim is to investigate the two-dimensional, steady state, inviscid and adiabatic modeling of steam nucleating flows in three different nozzle and turbine blade geometries, flow simulation was performed using a relatively simple mesh and the innovative proposed hybrid method (scalar + CUSP, with the desired value of z = 2.667 . A comparison between the results of the hybrid modeling of the three main cases with experimental data showed a very good agreement, even within shock zones, including the condensation shock region, revealing the efficiency of this numerical modeling method innovation

  14. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    Directory of Open Access Journals (Sweden)

    Fic Adam

    2015-03-01

    Full Text Available Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle, which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle. The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

  15. Superheated emulsions: neutronics and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari]|[Yale Univ., New Haven, CT (United States). School of Medicine; Curzio, G. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Nath, R. [Yale Univ., New Haven, CT (United States). School of Medicine; Apfel, R.E. [Yale Univ., New Haven, CT (United States). Dept. of Mechanical Engineering; Dietz, E.; Guldbakke, S.; Siebert, B.R.L. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Egger, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Gualdrini, G.F. [ENEA, Bologna (Italy)

    1997-09-01

    The results of some recent theoretical and experimental investigations on the physics of superheated emulsions are presented. Computational fluid thermodynamics allowed for a detailed description of the temporal and spatial history of the energy deposition process by a charged particle in a superheated liquid. Despite the assumptions it is based upon, this model gives information in agreement with experimental data on bubble nucleation. The experimental findings concern the role of interfacial reactions between drops and emulsifier, the existence of inhibition temperatures for the detector`s response, and the progressive sensitisation to protons. (author).

  16. 汽轮机喷嘴室温度场分析%Analysis of the Temperature Field of Steam Turbine Nozzle Chamber

    Institute of Scientific and Technical Information of China (English)

    王林; 程荣新; 张宏涛; 李宇峰; 翁振宇

    2015-01-01

    Nozzle chamber is one of the key components in steam turbine , the analysis of the temperature field is important when nozzle chamber of steam turbine is designed .Aim at a 600MW sub-critical steam turbine nozzle chamber , a three-dimensional finite element model of the nozzle chamber is developed , methods for calculating the convective heat transfer coefficients of the nozzle chamber surfaces different regions are described , three-dimensional transient thermal analysis is performed on the nozzle chamber by using finite element method .Detailed temperature distributions are determined during the cold start transient operating conditions .The results show that temperature distributions of the active chambers and those of the inactive chambers are different , inner surface temperature is higher than other surfaces temperature for the active chambers, temperatures of the contact surfaces between the inner casing and the support lugs on the nozzle chamber are lowest.The used analytic methods can be applied for temperature field analysis of sub-critical, supercritical and ultra-supercritical steam turbine nozzle chamber , a basis for the cooling design and the life evaluation of steam turbine nozzle chamber is provided .%喷嘴室是汽轮机中的关键部件,在汽轮机喷嘴室的设计过程中,必须分析其温度场。针对某亚临界600MW汽轮机喷嘴室,建立了三维有限元模型,介绍了喷嘴室表面不同区域的对流换热系数计算方法,用有限元法分析了喷嘴室的三维瞬态温度场,得出了在冷态启动运行工况的详细温度分布。结果表明,喷嘴室开启的室和关闭的室温度分布不同,对于开启的室,内表面的温度明显高于其它表面,内缸和喷嘴室支承键的接触表面处温度最低。所采用的分析方法可以用于分析亚临界、超临界和超超临界汽轮机喷嘴室,为喷嘴室的冷却设计和寿命评估打下了基础。

  17. Research on new type of fast-opening mechanism in steam turbine regulating system and optimization of operation tactic

    Institute of Scientific and Technical Information of China (English)

    Xiao-xiao LI; Xuan-yin WANG; Fu-shang LI

    2008-01-01

    With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward, To overcome the defect, different operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.

  18. Fe Analysis of a Steam Turbine HP Rotor Blade Stage Concerning Material Effort, Dynamic Properties and Creep Damage Assessment

    Directory of Open Access Journals (Sweden)

    Borkowski Paweł

    2016-03-01

    Full Text Available This paper is concerned with the 1st stage of HP rotor blade assembly steam turbine TK 120. The methodology was focused on the selection of mechanical properties and the way of the rotor disc modeling and estimating the degree of damage caused by creep. Then the dynamic interference between the frequencies of excitation and the natural frequencies was assessed. Static calculations were performed for the cyclic sectors consisting of the disc, disc blades, spacers and shrouding, including loads as temperature, mass forces from the angular velocity and the pressure on the blades. Then, the creep analysis using a Norton’s model and the modal analysis were performed. Static analysis gave information concerning the distributions of displacements, stress and strain components. In the creep analysis, the creep displacements and stress relaxation versus time were determined and the estimated degree of damage caused by creep was evaluated at each part of the rotor disc. In the modal analysis, the natural frequencies and modes of vibrations corresponding to the nodal diameters were found. The results of modal analysis were shown in the SAFE graph. Numerical calculations have shown that the rotor disc was a well-designed structure and did not reveal any dynamic interference.

  19. Unsteady Numerical Simulation of Steam-Solid Two-Phase Flow in the Governing Stage of a Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    Yufeng Li; Peigang Yan; Wanjin Han

    2009-01-01

    Solid particle erosion (SPE) in an ultra-supercritical steam turbine control stage with block configuration is inves-tigated numerically, based on the finite volume method and the fluid-particle coupling solver. We apply the parti-cle discrete phase model to model the solid particles flow, and use the Euler conservation equations to solve the continuous phase. The investigation is focused on the influence of the solid particle parameters (such as particle diameter, particle velocity and particle trajectory) on the erosion rate of the stator and rotor blade surface in un-steady condition. The distributions of the highly eroded zone on the stator and rotor blade surfaces are shown and discussed in detail according to the mechanism of solid particle/blade wall interaction. We obtain that the erosion rate of the vane blade is sensitive to the fluctuation of the potential flow field, and the smaller particle has a greater impact on the erosion distribution of rotor blade. The erosion rate does not entirely depend on the diameter size of the solid particle.

  20. Ecotaxes and their impact in the cost of steam and electric energy generated by a steam turbine system

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Gisela [Universidad Autonoma de Baja California, Mexicali, B.C. (Mexico). Instituto de Ingenieria; Pulido, Ricardo; Pineda, Carlos; Rivero, Ricardo [Instituto Mexicano del Petroleo, Eje Lazaro Cardenas, D.F. (Mexico)

    2006-12-15

    Ecotaxes allow the internalization of costs that are considered externalities associated with polluting industrial process emissions to the atmosphere. In this paper, ecotaxes internalize polluting emissions negative impacts that are added to electricity and steam generated costs of a steam turbine and heat recovery systems from a utilities refinery plant. Steam costs were calculated by means of an exergy analysis tool and Aspen Plus simulation models. Ecotaxes were calculated for specific substances emitted in the refinery flue gases, based on a toxicity and pollution scale. Ecotaxes were generated from a model that includes damages produced to biotic and abiotic resources and considers the relative position of those substances in a toxicity and pollution scale. These ecotaxes were internalized by an exergoeconomic analysis resulting in an increase in the cost per kWh produced. This kind of ecotax is not applied in Mexico. The values of ecotaxes used in the cost determination are referred to the values currently applied by some European countries to nitrogen oxides emissions. (author)

  1. Study of practical cycles for geothermal power plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Eskesen, J.H.

    1977-04-01

    A comparison is made of the performance and cost of geothermal power cycles designed specifically, utilizing existing technology, to exploit the high temperature, high salinity resource at Niland and the moderate temperature, moderately saline resource at East Mesa in California's Imperial Valley. Only two kinds of cycles are considered in the analysis. Both employ a dual flash arrangement and the liberated steam is either utilized directly in a condensing steam turbine or used to heat a secondary working fluid in a closed Rankine (binary) cycle. The performance of several organic fluids was investigated for the closed cycle and the most promising were selected for detailed analysis with the given resource conditions. Results show for the temperature range investigated that if the noncondensible gas content in the brine is low, a dual flash condensing steam turbine cycle is potentially better in terms of resource utilization than a dual flash binary cycle. (The reverse is shown to be true when the brine is utilized directly for heat exchange.) It is also shown that despite the higher resource temperature, the performance of the dual flash binary cycle at Niland is degraded appreciably by the high salinity and its output per unit of brine flow is almost 20 percent lower than that of the steam turbine cycle at East Mesa. Turbine designs were formulated and costs established for power plants having a nominal generating capacity of 50 MW. Three cycles were analyzed in detail. At East Mesa a steam turbine and a binary cycle were compared. At Niland only the binary cycle was analyzed since the high CO/sub 2/ content in the brine precludes the use of a steam turbine there. In each case only the power island equipment was considered and well costs and the cost of flash separators, steam scrubbers and piping to the power plant boundary were excluded from the estimate.

  2. 汽轮机安全经济运行中的监视与调整探究%On the Monitoring and Adjusting of Steam Turbine in the Safe and Economic Operation Process

    Institute of Scientific and Technical Information of China (English)

    武鑫

    2015-01-01

    Steam turbine is one of the three largest hosts of coal-fired power plants, is a large rotating equipment, and is also a major part of the work unit. Proper maintenance, adjusting monitoring of the steam turbine in the operation is the condition to ensure the normal operation of steam turbine. We can install necessary monitoring and protection equipment on steam turbine In the process of normal operation to real-time monitor various parameters in the running of steam turbine and ensure safe and economic operation of steam turbine. This paper studied the monitoring and adjusting of steam turbine in the safe and economic operation process.%汽轮机是火力发电厂的三大主机之一,是大型转动设备,也是机组做功的主要部件。在汽轮机运行中对设备进行正确维护、调整和监视,是保证汽轮机安全经济运行的条件。在正常运行过程中,可以在汽轮上安设必要的监视和保护设备,对汽轮机运行过程中的各项参数实现实时监控,确保汽轮机运行的安全经济性。对汽轮机安全经济运行中的监视与调整进行了探究。

  3. Numerical investigation of methane combustion under mixed air-steam turbine conditions – FLAMESEEK

    NARCIS (Netherlands)

    Skevis, G.; Chrissanthopoulos, A.; Goussis, D.A.; Mastorakos, E.; Derksen, M.A.F.; Kok, J.B.W.

    2004-01-01

    Lowering emissions from power generating gas turbines, while retaining efficiency and power output, constitutes a formidable task, both at fundamental and technical levels. Combined gas turbine cycles involving air humidification are particularly attractive, since they provide additional power with

  4. Detection in superheated water chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Chienthavorn, O

    1999-11-01

    Superheated water has been used successfully as an eluent in liquid chromatography and has been coupled to various modes of detection, ultraviolet (UV), fluorescence, and nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). A number of compounds were examined on poly(styrene-divinylbenzene) (PS-DVB), polybutadiene (PBD), and octadecylsilyl bonded silica (ODS) column with isothermal and temperature programmes. The PS-DVB column was mostly used throughout the project as it was the most stable. Not only pure water could serve as superheated water mobile phase; inorganic buffered water and ion-pairing reagent with a concentration of 1-3 mM of the buffer and reagent were also exploited. It was shown that the pH could be controlled during the separation without salt precipitation and the separations followed a conventional reversed-phase HPLC method. Results from fluorescence detection showed good separation of a series of vitamins, such as pyridoxine, riboflavin, thiamine, and some analgesics. The relationship of riboflavin using the detection was linear and the detection limit was seven times higher than that of a conventional method. Simultaneous separation and identification using superheated water chromatography-NMR was demonstrated. With using a stop flow method, NMR spectra of model drugs, namely barbiturates, paracetamol, caffeine and phenacetin were obtained and the results agreed with reference spectra, confirming a perfect separation. A demonstration to obtain COSY spectrum of salicylamide was also performed. The method was expanded to the coupling of superheated water LC to NMR-MS. Results from the hyphenated detection method showed that deuteration and degradation happened in the superheated water conditions. The methyl group hydrogens of pyrimidine ring of sulfonamide and thiamine were exchanged with deuterium. Thiamine was decomposed to 4-methyl-5-thiazoleethanol and both were deuterated under the conditions. (author)

  5. Useful life extension of steam turbine rotors; Alargamiento de la vida en rotores de turbina de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Arelle, Carlos [Turbomaquinas S. A. de C.V., La Piedad, Michoacan (Mexico)

    2007-11-15

    The continuous use of steam turbines, the chemistry of the steam itself and the variations of operation velocities, cause the gradual deterioration by erosion, oxidation and/or corrosion of the rotors and blades. When this happens most of the original manufacturers recommend to rectify the areas, diminishing the surfaces, or to compare with a new rotor. TURBOMAQUINARIAS S.A. de C.V. has developed the most reliable and safe methods to return the rotor to its original dimensions and in case of recurrent problems such as erosion, oxidation and/or wear, it offers the alternative of attaching coatings metallurgically compatible with which these problems are eliminated or diminished that might show up on the rotor surface as well as in the body of the discs or of the blades. These restoring methods are recommended by the international standards such as API 687. [Spanish] El uso continuo de las turbinas de vapor, la quimica del mismo vapor y la variacion de las velocidades de operacion, ocasionan el deterioro gradual por erosion, oxidacion y/o corrosion de los rotores y de los alabes. Al ocurrir esto la mayoria de los fabricantes originales recomiendan rectificar las areas, disminuyendo las superficies, o bien comparar un rotor nuevo. TURBOMAQUINARIAS S.A. de C.V. ha desarrollado los metodos mas confiables y seguros para devolver a su rotor las dimensiones originales y en caso de problemas recurrentes tales como erosion, oxidacion y/o desgaste, ofrece la alternativa de agregar recubrimientos metalurgicamente compatibles con los cuales se eliminan o se disminuyen estos problemas que pueden presentarse tanto en la superficie del rotor como del cuerpo de los discos o bien de los alabes. Estos metodos de restauracion son recomendados por las normas internacionales tales como la API 687.

  6. Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters based on response surface method

    Institute of Scientific and Technical Information of China (English)

    Wei DUAN

    2008-01-01

    Many stochastic parameters have an effect on the reliability of a steam turbine blade during practical operation. To improve the reliability of blade design, it is necessary to take these stochastic parameters into account. An equal cross-section blade is investigated and a finite element model is built parametrically. Geometrical parameters, material parameters and load parameters of the blade are considered as input random variables while the maximum deflection and maximum equivalent stress are output random variables. Analysis file of the blade is compiled by deterministic finite element method and applied to be loop file to create sample points. A quadratic polynomial with cross terms is chosen to regress these samples by step-forward regression method and employed as a surrogate of numerical solver to drastically reduce the number of solvers call. Then, Monte Carlo method is used to obtain the statistical characteristics and cumulative distribution function of the maximum deflection and maximum equivalent stress of the blade. Probability sensitivity analysis, which combines the slope of the gradient and the width of the scatter range of the random input variables, is applied to evaluate how much the output parameters are influenced by the random input para-meters. The scatter plots of structural responses with respect to the random input variables are illustrated to analyze how to change the input random variables to improve the reliability of the blade. The results show that combination of the finite element method, the response surface method and Monte Carlo method is an ideal way for the reliability analysis and probability strength design of the blade.

  7. Corrosion fatigue in LP steam turbine blading - experiences, causes and appropriate measures; Korrosionsutmattning i aangturbinskovlar - Erfarenheter, inverkande faktorer och moejliga aatgaerder

    Energy Technology Data Exchange (ETDEWEB)

    Tavast, J. [ABB STAL AB, Finspaang (Sweden)

    1996-12-01

    Corrosion fatigue in LP steam turbine blading was reviewed together with result of tests performed in order to find blade materials with improved resistance against this. According to international experience, corrosion fatigue of 12Cr steam turbine blades in the transition zone between dry and wet steam, is one of the major causes, if not the major cause, for unavailability of steam turbines. Corrosion fatigue in LP blading is a frequent problem also in Swedish and Finnish nuclear power plants, especially in turbines of type D54 in BWR-plants. Corrosion fatigue has also been discovered in at least one type of nuclear turbine. Initiation times have been very long and the varying experiences in different types of turbines may simply reflect differing initiation times. Corrosion fatigue may therefore become more frequent in other types of turbines in the future. The type of water treatment (BWR/PWR) and possibly temperature after reheating seem to influence the risk for corrosion fatigue. Influence of inleakage of cooling water is less clear for these nuclear plants. The long initiation times together with the fact that very few of the cracked blades have actually failed, indicate that the cracks initiate and/or propagate during transients. Extensive laboratory tests show that there are alternative blade materials available with improved resistance against corrosion fatigue, with the most promising being 15/5 PH and A905, together with Ti6Al4V. The Ti alloy shows the best resistance against corrosion fatigue in most environments and is already used in some turbines. Disadvantage is a higher cost and possible need for redesign of the blades. The alternative materials are recommended for use for blades in the transition zone between dry and wet steam in LP turbines. The main disadvantage is a lack of references, even if 15%5 PH has been used to a very limited extent. 40 refs, 24 figs, 12 tabs, 9 appendices

  8. Development of CAD/CAM software for steam turbine-blades%汽轮机叶片CAD/CAM软件开发

    Institute of Scientific and Technical Information of China (English)

    石勇; 刘文涛; 于红英

    2011-01-01

    由于通用CAD/CAM软件存在难以实现汽轮机叶片参数化三维建模,在变轴加工过程中不能进行变前倾角、变侧倾角加工和拐角减速等问题,开发了汽轮机叶片CAD/CAM软件.软件通过研究汽轮机叶片各曲面特征建模方法,实现叶片零件参数化建模;通过研究刀具轨迹计算公式,设置叶片各曲面段不同工艺参数,获得了叶片粗加工、螺旋精加工和清根加工的变参数轨迹规划方法,并解决了以上问题.%In order to solve the problems that, with the commonly used CAD/CAM software, it is difficult to carry out 3D modeling of steam-turbine-blade parameterization, and the variable leader angle, variable tilt angler, and speed-down at comers can not achieved during variable axis machining, a CAD/CAM software for steam-turbine-blades is developed. By studying the modeling method of various curve features for the steam-turbine-blade, this software can carry out parametric modeling of the blade parts.Through studying the calculation formula for the tool path and setting different process parameters for each curve section, the variable parameter trajectory planning method for blade rough machining,spiral finishing and Clean-up cutting are achieved, and above mentioned problems are solved.

  9. Increasing of Manoeuvrability of Cogeneration Combined Cycle Power Plants Owing to the Usage of Electric Boilers

    Directory of Open Access Journals (Sweden)

    S. Kachan

    2013-01-01

    Full Text Available The paper contains the results of efficiency evaluation  of using the electric boilers to improve maneuver capabilities of the cogeneration combined cycle power plants (as an example, 230 MW combined cycle unit of Minsk CHP-3 in comparison with the traditional steam-turbine units of cogeneration power plants.

  10. Materials for Ultra-long Last Stage Blade of LP Steam Turbine%低压汽轮机末级超长叶片材料

    Institute of Scientific and Technical Information of China (English)

    彭建强; 李宇峰

    2015-01-01

    因为末级叶片长度决定了低压汽缸的数量、汽轮机的总长并最终决定电厂占地尺寸,对机组效率和电厂的建设成本有很大影响,所以末级叶片是汽轮机中非常关键的部件.然而,由于末级叶片尺寸大,工况条件严苛,对材料有着非常高的要求.因此,世界各国的汽轮机制造商都非常重视末级叶片材料的研发.目前,共有3类末级叶片材料,即;马氏体不锈钢、沉淀硬化不锈钢和钛合金.文章介绍了广泛使用及最新研发的末级叶片材料,比较了钢制和钛合金末级叶片材料的优缺点,并结合国内超长尺寸末级叶片模锻件制造能力,对国内高参数超超临界汽轮机超长叶片材料的研发给出了建议.%The length of the last stage blade (LSB) decides the number of the LP casing and the total length of the steam turbine, further decides the total area of the whole power plant, and influences the unit's efficiency and construction cost of the power plant significantly, so the LSB is the critical part of the steam turbine. However, the size of the LSB is huge, and the working condition of the LSB is severe, so the property requirement for the LSB material is very high. Hence, steam turbine manufacturers all over the world pay attention to the research and development (R&D) of the LSB material. Up to now, there are three types of LSB materials:matensitic stainless steel, precipitating hardening stainless steel and titanium alloy. This paper introduces the LSB material which is wildly used and newly developed, and compares the advantage and disadvantage of the LSB made of steel and titanium alloy, and gives R&D suggestions for the LSB material for the domestic USC steam turbine with high parameters, based on the die forging manufacture ability for the ultra-long LBS in China.

  11. 汽轮机调节级动叶叶根产生裂纹的原因调查%An Investigation on the Cracks on Control Stage Blade Root of Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    王广坤

    2015-01-01

    通过对汽轮机调节级动叶叶根抽样调查,得出其枞树叶根产生裂纹的根本原因,并就此提出汽轮机叶片更换时相关的具体措施,对汽轮机检修进行部分叶片更换具有一定的指导作用.%Through spot check of the control stage blade of steam turbine, the primary causes of cracking on the fir blade roots were found out and specific measures for changing steam turbine blades were put forward, to provide some guidance for changing blades in steam turbine maintenance.

  12. Surface boiling of superheated liquid

    Energy Technology Data Exchange (ETDEWEB)

    Reinke, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-01-01

    A basic vaporization mechanism that possibly affects the qualitative and quantitative prediction of the consequences of accidental releases of hazardous superheated liquids was experimentally and analytically investigated. The studies are of relevance for the instantaneous failure of a containment vessel filled with liquefied gas. Even though catastrophical vessel failure is a rare event, it is considered to be a major technological hazard. Modeling the initial phase of depressurisation and vaporization of the contents is an essential step for the subsequent analysis of the spread and dispersion of the materials liberated. There is only limited understanding of this inertial expansion stage of the superheated liquid, before gravity and atmospheric turbulence begin to dominate the expansion. This work aims at a better understanding of the vaporization process and to supply more precise source-term data. It is also intended to provide knowledge for the prediction of the behavior of large-scale releases by the investigation of boiling on a small scale. Release experiments with butane, propane, R-134a and water were conducted. The vaporization of liquids that became superheated by sudden depressurisation was studied in nucleation-site-free glass receptacles. Several novel techniques for preventing undesired nucleation and for opening the test-section were developed. Releases from pipes and from a cylindrical geometry allowed both linear one-dimensional, and radial-front two-dimensional propagation to be investigated. Releases were made to atmospheric pressure over a range of superheats. It was found that, above a certain superheat temperature, the free surface of the metastable liquid rapidly broke up and ejected a high-velocity vapor/liquid stream. The zone of intense vaporization and liquid fragmentation proceeded as a front that advanced into the test fluids. No nucleation of bubbles in the bulk of the superheated liquid was observed. (author) figs., tabs., refs.

  13. Combined gas/steam turbine power plants with coal fired steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, H.J.; Weirich, P.H. [ABB Kraftwerke AG, Mannheim (Germany)

    1994-12-31

    The combination of coal fired steam power plants with natural gas fired gas turbines results in an essential efficiency increase, up to 50%, requiring a portion of around one third of the fuel heat input in form of natural gas. There are two basic types of circuit arrangements in this category: in a topping process the gas turbine is connected to the steam generator on the gas side, and in a compound cycle power plant gas turbine and steam circuit are connected to each other on the water/steam side via a heat recovery steam generator. If comparable design parameters are applied slightly higher plant efficiencies can be obtained with the topping process. With respect to a higher power plant availability it is possible to operate both types of circuit arrangement without gas turbine. The specific investment cost of such combined cycle power plants is lower than that of corresponding steam power plants. Hence, they can represent economical solutions as far as the price ratio between natural gas and coal is not extremely high. In ecological respects, the advantage of this combination is a reduction of the specific CO{sub 2} emission by around 20-25%, compared with pure steam power plants. 1 ref., 9 figs., 2 tabs.

  14. Thermionic combustor application to combined gas and steam turbine power plants

    Science.gov (United States)

    Miskolczy, G.; Wang, C. C.; Lieb, D. P.; Margulies, A. E.; Fusegni, L. J.; Lovell, B. J.

    A design for the insertion of thermionic converters into the wall of a conventional combustor to produce electricity in a topping cycle is described, and a study for applications in gas and steam generators of 70 and 30 MW is evaluated for engineering and economic feasibility. Waste heat from the thermionic elements is used to preheat the combustor air; the heat absorbed by the elements plus further quenching of the exhaust gases with ammonia is projected to reduce NO(x) emissions to acceptable levels. Schematics, flow diagrams, and components of a computer model for cost projections are provided. It was found that temperatures around the emitters must be maintained above 1,600 K, with maximum efficiency and allowable temperature at 1,800 K, while collectors generate maximally at 950 K, with a corresponding work function of 1.5 eV. Cost sensitive studies indicate an installed price of $475/kW for the topping cycle, with improvements in thermionic converter characteristics bringing the cost to $375/kW at a busbar figure of 500 mills/kWh.

  15. Discussion on the Causes and Countermeasures for the Fracture of the Steam Turbine Rotor of Aromatics Isomerization%芳烃异构化汽轮机转子断裂原因及应对措施研究

    Institute of Scientific and Technical Information of China (English)

    宁飞升; 郭鸿飞; 高飞

    2015-01-01

    对芳烃异构化汽轮机转子断裂原因进行分析,制订了预防转子断裂的方案,并提出了汽轮机转子安全运行的建议.%To analyze the causes of the fracture of the steam turbine rotor with aromatics isomerization, a scheme to pre-vent the rotor fracture is developed, and some suggestions for the safe operation of the steam turbine rotor are put forward.

  16. 700℃等级超超临界汽轮机用材探讨%Discussion on the Materials of 700℃Class Ultra-super Critical Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    彭建强

    2014-01-01

    By combining domestic and international advanced research data of materials for ultra -super critical steam turbine , this paper provides the candidate materials as well as research and development focus of material tech -nology in China for 700℃class steam turbine .%综合国内外先进超超临界汽轮机材料方面的研究资料,给出我国700℃等级汽轮机用候选材料及材料技术的研发重点。

  17. 基于支持向量机的汽轮机振动故障诊断系统%Vibration Fault Diagnosis of Steam Turbine Based on SVM

    Institute of Scientific and Technical Information of China (English)

    韩中合; 刘明浩

    2013-01-01

    以MATLAB为开发平台构建了一套汽轮机振动故障诊断系统.该系统以支持向量机算法为核心,并通过建立支持向量机多分类模型对汽轮机常见故障进行了精确的诊断.%This paper develops a set of steam turbine vibration fault diagnosis system based on the development platform of MATLAB. The system uses the SVM algorithm as the core,and diagnoses the common faults of steam turbine accurately through establishing multiple classification SVM model.

  18. Materials for Advanced Ultra-supercritical (A-USC) Steam Turbines – A-USC Component Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Purgert, Robert [Energy Industries Of Ohio Inc., Independence, OH (United States); Phillips, Jeffrey [Energy Industries Of Ohio Inc., Independence, OH (United States); Hendrix, Howard [Energy Industries Of Ohio Inc., Independence, OH (United States); Shingledecker, John [Energy Industries Of Ohio Inc., Independence, OH (United States); Tanzosh, James [Energy Industries Of Ohio Inc., Independence, OH (United States)

    2016-10-01

    these components determining the optimum test location. The first step of the ComTest, the steam turbine test, was determined best suited for a site in Youngstown, Ohio. Efforts were also undertaken to identify and evaluate other potential sites for high pressure testing.

  19. Control of Auxiliary System for USC Steam Turbines%超超临界汽轮机辅助系统的控制

    Institute of Scientific and Technical Information of China (English)

    李刚

    2016-01-01

    介绍了超超临界汽轮机辅助系统的控制策略,包括本体疏水、抽汽逆止阀、汽封及油系统四个方面的内容。通过详细分析各子系统的控制特点,论证了超超临界汽轮机辅助系统控制的独特性和先进性。掌握这种控制策略,可为新系统开发提供理论参照。%The control strategy including turbine drains ,extraction non‐return valves ,gland seal and oil system for auxiliary system of USC steam turbines is presented .Based on analysis of the control characteristics of each subsystem ,the unique features and advances in this system are demonstrated .The strategy shall be regarded as theoretical reference for developing the new system of USC steam turbines .

  20. 蜂窝汽封在中小型汽轮机组的应用%Application of Honeycomb Steam Seal in Medium and Small Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    江丽红; 毛吉献

    2016-01-01

    This paper introduces the structure and working principle of cellular steam seal and its advantages compared with the traditional comb , focusing on the steam seal technology application in medium and small gas turbine generator set . According to the actual application effect conclusion can be drawn that it has a notable effect in the steam seal technology in steam turbine steam for reducing leakage , and improved the efficiency of steam turbine .%本文介绍了蜂窝汽封的结构及工作原理,分析了该汽封与传统梳齿密封相比的优势,重点阐述了该汽封技术在中小型汽轮机组的应用,根据应用的实际效果,可以得出该汽封技术在降低汽轮机蒸汽泄漏量、提高汽轮机效率上效果显著。

  1. Enhanced Droplet Erosion Resistance of Laser Treated Nano Structured TWAS and Plasma Ion Nitro-Carburized Coatings for High Rating Steam Turbine Components

    Science.gov (United States)

    Pant, B. K.; Arya, Vivek; Mann, B. S.

    2010-09-01

    This article deals with surface modification of twin wire arc sprayed (TWAS) and plasma ion nitro-carburized X10CrNiMoV1222 steel using high power diode laser (HPDL) to overcome water droplet erosion occurring in low pressure steam turbine (LPST) bypass valves and LPST moving blades used in high rating conventional, critical, and super critical thermal power plants. The materials commonly used for high rating steam turbines blading are X10CrNiMoV1222 steel and Ti6Al4V titanium alloy. The HPDL surface treatment on TWAS coated X10CrNiMoV1222 steel as well as on plasma ion nitro-carburized steel has improved water droplet resistance manifolds. This may be due to combination of increased hardness and toughness as well as the formation of fine grained structure due to rapid heating and cooling rates associated with the laser surface treatment. The water droplet erosion test results along with their damage mechanism are reported in this article.

  2. 一起罕见的汽轮机油变绿原因分析%Reason Analysis on One Rare Event of Steam Turbine Oil Changing Green

    Institute of Scientific and Technical Information of China (English)

    万涛; 李臻; 周舟; 何铁祥; 冯兵; 龚尚昆

    2015-01-01

    In allusion to problems of steam turbine oil discoloring and its abnormality in practical production,this paper ana-lyzes various performance index of steam turbine oil and considers that colored substances could not affect usability of the oil while antioxidant may cause the oil discolor. Gas chromatography-mass spectrometer(GC-MS)and ultraviolet spectrum anal-ysis was conducted for extracted green substances and it was discovered reason for oil discoloring was partially using alkylated diphenylamines antioxidant. Meanwhile,it was pointed out that XDHX-1 typed high-effective adsorbent had good desorp-tion effect for colored substances.%针对生产实际中汽轮机油变色、不正常的问题,分析了汽轮机油各项性能指标,认为发色物质并未影响油品使用性能,可能为抗氧化剂造成变色。将萃取的绿色物质进行气质联用和紫外光谱分析,发现油品变色应为部分使用了烷基化二苯胺新型抗氧化剂所致,并指出 XDHX-1型高效吸附剂对发色物质具有良好的脱除效果。

  3. Influence of steam leakage through vane, gland, and shaft seals on rotordynamics of high-pressure rotor of a 1,000 MW ultra-supercritical steam turbine

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, P.N. [Shanghai Jiao Tong University, Key Laboratory of Power Machinery and Engineering, Ministry of Education, School of Mechanical Engineering, Shanghai (China); Shanghai Turbine Company, Department of R and D, Shanghai (China); Wang, W.Z.; Liu, Y.Z. [Shanghai Jiao Tong University, Key Laboratory of Power Machinery and Engineering, Ministry of Education, School of Mechanical Engineering, Shanghai (China); Meng, G. [Shanghai Jiao Tong University, State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai (China)

    2012-02-15

    A comparative analysis of the influence of steam leakage through vane, gland, and shaft seals on the rotordynamics of the high-pressure rotor of a 1,000 MW ultra-supercritical steam turbine was performed using numerical calculations. The rotordynamic coefficients associated with steam leakage through the three labyrinth seals were calculated using the control-volume method and perturbation analysis. A stability analysis of the rotor system subject to the steam forcing induced by the leakage flow was performed using the finite element method. An analysis of the influence of the labyrinth seal forcing on the rotordynamics was carried out by varying the geometrical parameters pertaining to the tooth number, seal clearance, and inner diameter of the labyrinth seals, along with the thermal parameters with respect to pressures and temperatures. The results demonstrated that the steam forcing with an increase in the length of the blade for the vane seal significantly influences the rotordynamic coefficients. Furthermore, the contribution of steam forcing to the instability of the rotor is decreased and increased with increases in the seal clearance and tooth number, respectively. The comparison of the rotordynamic coefficients associated with steam leakage through the vane seal, gland seal, and shaft seal convincingly disclosed that, although the steam forcing attenuates the stability of the rotor system, the steam turbine is still operating under safe conditions. (orig.)

  4. Numerical Research of Steam and Gas Plant Efficiency of Triple Cycle for Extreme North Regions

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2016-01-01

    Full Text Available The present work shows that temperature decrease of heat rejection in a cycle is necessary for energy efficiency of steam turbine plants. Minimum temperature of heat rejection at steam turbine plant work on water steam is 15°C. Steam turbine plant of triple cycle where lower cycle of steam turbine plant is organic Rankine cycle on low-boiling substance with heat rejection in air condenser, which safely allows rejecting heat at condensation temperatures below 0°C, has been offered. Mathematical model of steam and gas plant of triple cycle, which allows conducting complex researches with change of working body appearance and parameters defining thermodynamic efficiency of cycles, has been developed. On the basis of the model a program of parameters and index cycles design of steam and gas plants has been developed in a package of electron tables Excel. Numerical studies of models showed that energy efficiency of steam turbine plants of triple cycle strongly depend on low-boiling substance type in a lower cycle. Energy efficiency of steam and gas plants net 60% higher can be received for steam and gas plants on the basis of gas turbine plant NK-36ST on pentane and its condensation temperature below 0°C. It was stated that energy efficiency of steam and gas plants net linearly depends on condensation temperature of low-boiling substance type and temperature of gases leaving reco very boiler. Energy efficiency increases by 1% at 10% decrease of condensation temperature of pentane, and it increases by 0.88% at 15°C temperature decrease of gases leaving recovery boiler.

  5. 火电厂600MW超临界机组汽轮机胀差控制分析%Steam Turbine Differential Expansion Controlling Analysis of 600 MW Supercritical Unit in Thermal Power Plant

    Institute of Scientific and Technical Information of China (English)

    杨晨; 朱懿

    2012-01-01

    N600-24.2/566/566 supercritical steam turbine which is made by Shanghai Steam Turbine Plant, for example, importance and variation of differential expansion controlling of steam turbine, mutual relations of the rotor and stator expansion, and the most effective technical measures of controlling differential expansion in the start-up process of Phase I 2 x 600 MW supercritical steam turbine of Huangjinbu Power Generation Co.,Ltd. of State Power Grid in Jiangxi were analyzed, and had some reference values for other turbines.%以上海汽轮机厂生产的N600.24.2/566/566型超临界汽轮机为例,分析了江西国电黄金埠发电有限公司1期2台600MW超临界汽轮机启动过程中,汽轮机胀差控制的重要性、变化规律、转子和静子膨胀的相互关系以及采取的最有效的控制胀差的技术措施,对于其它汽轮机具有一定的参考价值。

  6. Melting of superheated molecular crystals

    Science.gov (United States)

    Cubeta, Ulyana; Bhattacharya, Deepanjan; Sadtchenko, Vlad

    2017-07-01

    Melting dynamics of micrometer scale, polycrystalline samples of isobutane, dimethyl ether, methyl benzene, and 2-propanol were investigated by fast scanning calorimetry. When films are superheated with rates in excess of 105 K s-1, the melting process follows zero-order, Arrhenius-like kinetics until approximately half of the sample has transformed. Such kinetics strongly imply that melting progresses into the bulk via a rapidly moving solid-liquid interface that is likely to originate at the sample's surface. Remarkably, the apparent activation energies for the phase transformation are large; all exceed the enthalpy of vaporization of each compound and some exceed it by an order of magnitude. In fact, we find that the crystalline melting kinetics are comparable to the kinetics of dielectric α-relaxation in deeply supercooled liquids. Based on these observations, we conclude that the rate of non-isothermal melting for superheated, low-molecular-weight crystals is limited by constituent diffusion into an abnormally dense, glass-like, non-crystalline phase.

  7. Research on the Steam Turbine Static Blade Assembly Back Curved Surface Line Cutting Process%汽轮机静叶片装配内背弧型面线切割工艺研究

    Institute of Scientific and Technical Information of China (English)

    毛鹏枭; 李双跃; 谌永祥; 刘勇; 曾岳飞

    2013-01-01

    The back curved surface machining of the steam turbine static blade assembly is one of the key processes of the steam turbine static blade. For the steam turbine static blade structural characteristics,applying WEDM and workpiece positioning principle,the steam turbine static blade machining process,WEDM process of the back curved surface in the steam turbine static blade assembly,WEDM fixture structure,workpiece clamping principle,adjustment method of WEDM process parameters were researched. So the machined part accuracy and surface roughness requirements are met and the perfect machining processing is formed in production.%  汽轮机静叶片装配内背弧型面加工是汽轮机静叶片关键工序之一。针对汽轮机静叶片结构特征,应用线切割加工技术和工件定位原理,研究汽轮机静叶片加工工艺过程、装配内背弧型面线切割工艺、线切割夹具结构及夹紧工作原理、线切割工艺参数的调整方法,从而在满足加工零件的精度及表面粗糙要求的同时,在生产应用中形成了更加完善的工艺方法。

  8. Development of a thermal scheme for a cogeneration combined-cycle unit with an SVBR-100 reactor

    Science.gov (United States)

    Kasilov, V. F.; Dudolin, A. A.; Krasheninnikov, S. M.

    2017-02-01

    At present, the prospects for development of district heating that can increase the effectiveness of nuclear power stations (NPS), cut down their payback period, and improve protection of the environment against harmful emissions are being examined in the nuclear power industry of Russia. It is noted that the efficiency of nuclear cogeneration power stations (NCPS) is drastically affected by the expenses for heat networks and heat losses during transportation of a heat carrier through them, since NPSs are usually located far away from urban area boundaries as required for radiation safety of the population. The prospects for using cogeneration power units with small or medium power reactors at NPSs, including combined-cycle units and their performance indices, are described. The developed thermal scheme of a cogeneration combined-cycle unit (CCU) with an SBVR-100 nuclear reactor (NCCU) is presented. This NCCU should use a GE 6FA gasturbine unit (GTU) and a steam-turbine unit (STU) with a two-stage district heating plant. Saturated steam from the nuclear reactor is superheated in a heat-recovery steam generator (HRSG) to 560-580°C so that a separator-superheater can be excluded from the thermal cycle of the turbine unit. In addition, supplemental fuel firing in HRSG is examined. NCCU effectiveness indices are given as a function of the ambient air temperature. Results of calculations of the thermal cycle performance under condensing operating conditions indicate that the gross electric efficiency η el NCCU gr of = 48% and N el NCCU gr = 345 MW can be achieved. This efficiency is at maximum for NCCU with an SVBR-100 reactor. The conclusion is made that the cost of NCCU installed kW should be estimated, and the issue associated with NCCUs siting with reference to urban area boundaries must be solved.

  9. How to compute the power of a steam turbine with condensation, knowing the steam quality of saturated steam in the turbine discharge

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Albarran, Manuel Jaime; Krever, Marcos Paulo Souza [Braskem, Sao Paulo, SP (Brazil)

    2009-07-01

    To compute the power and the thermodynamic performance in a steam turbine with condensation, it is necessary to know the quality of the steam in the turbine discharge and, information of process variables that permit to identifying with high precision the enthalpy of saturated steam. This paper proposes to install an operational device that will expand the steam from high pressure point on the shell turbine to atmosphere, both points with measures of pressure and temperature. Arranging these values on the Mollier chart, it can be know the steam quality value and with this data one can compute the enthalpy value of saturated steam. With the support of this small instrument and using the ASME correlations to determine the equilibrium temperature and knowing the discharge pressure in the inlet of surface condenser, the absolute enthalpy of the steam discharge can be computed with high precision and used to determine the power and thermodynamic efficiency of the turbine. (author)

  10. Design and Performance Test of Jet Pump for Marine Steam Turbine%船用汽轮机注油器设计与试验研究

    Institute of Scientific and Technical Information of China (English)

    王晗; 徐鹏

    2016-01-01

    The performances of jet pump in marine turbine are calculated in this paper with the method of numerical simulation. The test facilities are built to validate the performance of pump. The results show that the performance is fully satisfied with the demand and the off-design condition is excellent. All above work is the solid base of marine steam turbine development.%通过数值仿真对所设计船用汽轮机注油器进行了数值仿真,并详细分析了其变工况性能,并搭建试验台进行了性能验证,结果表明性能满足设计使用要求,并具有良好的变工况性能,为汽轮发电机组的研制创造了坚实的基础。

  11. A computationally efficient and accurate numerical representation of thermodynamic properties of steam and water for computations of non-equilibrium condensing steam flow in steam turbines

    Directory of Open Access Journals (Sweden)

    Hrubý Jan

    2012-04-01

    Full Text Available Mathematical modeling of the non-equilibrium condensing transonic steam flow in the complex 3D geometry of a steam turbine is a demanding problem both concerning the physical concepts and the required computational power. Available accurate formulations of steam properties IAPWS-95 and IAPWS-IF97 require much computation time. For this reason, the modelers often accept the unrealistic ideal-gas behavior. Here we present a computation scheme based on a piecewise, thermodynamically consistent representation of the IAPWS-95 formulation. Density and internal energy are chosen as independent variables to avoid variable transformations and iterations. On the contrary to the previous Tabular Taylor Series Expansion Method, the pressure and temperature are continuous functions of the independent variables, which is a desirable property for the solution of the differential equations of the mass, energy, and momentum conservation for both phases.

  12. Influence of Laser Power on the Hardening of Ti6Al4V Low-Pressure Steam Turbine Blade Material for Enhancing Water Droplet Erosion Resistance

    Science.gov (United States)

    Mann, B. S.; Arya, Vivek; Pant, B. K.

    2011-03-01

    To overcome water droplet erosion of Ti6Al4V alloy blade material used in low-pressure steam turbine (LPST) of high-rating nuclear and super critical thermal power plants, high-power diode laser (HPDL) surface treatment at two temperatures corresponding to two different power levels was carried out. During incubation as well as under prolonged erosion testing, the HPDL surface treatment of this alloy has enhanced its resistance significantly. This is due to the formation of fine-grained martensitic (ά) phase due to rapid heating and cooling associated with laser treatment. The droplet erosion test results after HPDL surface treatment on this alloy, SEM, XRD analysis, and residual stresses developed due to HPDL surface treatment are given in this paper.

  13. The nuclear power steam turbine modeling based on modular method%基于模块化方法的核动力汽轮机建模

    Institute of Scientific and Technical Information of China (English)

    余海燕; 杨永强; 汪伟

    2011-01-01

    汽轮机为核动力装置二回路系统重要部件,对整个系统的特性具有重要影响.根据模块化建模思想,将汽轮机划分为通用子模块,主要包括流动阻力型模块、流动存储型模块和转子模块.建立这些通用子模块的详细数学模型,利用不同模块的组合可以开发多种类型的汽轮机,提高汽轮机建模的效率.计算结果表明,建立的汽轮机模型可以满足大工况变动要求,为模拟整个核动力装置二回路系统提供可靠基础.%The steam turbine is an important component of the nuclear power plant second loop system,which has great influence on the characteristic of the power system.According to the modular method, the turbine is divided into some general sub modules, which mainly consist of the fluid resislive module,the fluid storage module and the rotational module.The advantage is that various turbines can he developed througb the assembly of the differenl modules,which improves the efficiency of steam turbine modeling.The results show that the models developed can successfully simulate the large disturbance transient process,and can provide reliable basis to simulate whole nuclear power plant second loop system.

  14. Adaptive nonlinear control for steam turbine governor%汽轮机调速系统的非线性自适应控制

    Institute of Scientific and Technical Information of China (English)

    俞华军; 李奇安; 李悦; 单海欧

    2012-01-01

    Steam turbine governor control has played an important role in not only improving power system transient stability but also restraining the low-frequency oscillation and bettering dynamic performance. Different from the former work based on the ideal steam turbine model with accurate parameter, this paper has proposed a nonlinear adaptive control strategy on the basis of comprehensive nonlinear model with inaccurate parameter by utilizing the differential geometry method and adaptive control theory. Simulation results demonstrate the effectiveness and advantages of the proposed control method.%汽轮机汽门开度控制不仅对电力系统暂态稳定性的改善有着重要的作用,并且对抑制电力系统低频振荡和改善动态品质也有着极其重要的作用,汽轮机调速器的控制器设计通常是基于具有准确参数的理想汽轮机模型。考虑了汽轮发电机固有的非线性以及汽轮机参数的不确定性,基于微分几何学理论和自适应控制方法推导了汽轮机调速的非线性自适应控制律。仿真结果表明了通过该方法设计控制器的有效性和优越性。

  15. Stationary phases for superheated water chromatography

    CERN Document Server

    Saha, S

    2002-01-01

    This project focused on the comparison of conventional liquid chromatography and superheated water chromatography. It examined the differences in efficiency and retention of a range of different stationary phases. Alkyl aryl ketones and eight aromatic compounds were separated on PBD-zirconia, Xterra RP 18, Luna C sub 1 sub 8 (2) and Oasis HLB columns using conventional LC and superheated water chromatography system. The retention indices were determined in the different eluents. On changing the organic component of the eluent from methanol to acetonitrile to superheated water considerable improvements were found in the peak shapes and column efficiencies on the PBD-zirconia and Oasis HLB columns. PS-DVB, PBD-zirconia and Xterra RP 18 columns have been used in efficiency studies. It was found that simply elevating the column temperature did not increase the efficiency of a separation in superheated water chromatography. The efficiency depended on flow rate, injection volume and also mobile phase preheating sys...

  16. 700℃以上超超临界汽轮机高中压转子用材研究%Research on the Materials of HP and MP Rotor of More than 700℃Ultra-supercritical Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    彭建强

    2013-01-01

    综合国外700℃以上汽轮机高中压转子材料研究情况,结合我国高温合金材料的发展水平,给出我国700℃以上超超临界汽轮机高中压转子用材建议。%Integrated with domestic and international research situation on HP and MP rotor of more than 700℃steam turbine , and combined with the development level of high temperature alloy materials in China , the suggestion are given for the material of HP and MP rotor of more than 700℃ultra-supercritical steam turbine in China .

  17. 基于600MW汽轮机组汽封改造的经济性评价%Economic Evaluation of Steam Sealing Reformation Based on 600 MW Steam Turbine Unit

    Institute of Scientific and Technical Information of China (English)

    王海亭; 郝金玉

    2011-01-01

    通过对传统式汽封与蜂窝式汽封的比较,论述了600MW汽轮机组采用蜂窝式汽封改造能够有效减少各级漏气量,提高汽轮机三缸效率、降低机组的热耗,并取得了良好的经济效益.%Comparing traditional steam seals with honeycomb steam seals, the technical transformations of 600 MW steam turbine units adopting honeycomb steam seals were discussed in the paper. Remarkable achievements have being obtained by means of the technical transformations mentioned above, such as the reduction of air leakage from all levels, the improvement of three-cylinder efficiency for steam turbine units and the drop of heat consumption for units. All in all, the considerable economic benefits have being made.

  18. Economics Effect and Optimization of Composite Steam Distribution Mode for Steam Turbine%汽轮机复合配汽方式对机组经济性的影响及优化

    Institute of Scientific and Technical Information of China (English)

    宗绪东

    2014-01-01

    本文针对汽轮机复合配汽方式进行了探讨,分析了节流调节影响经济性的机理,论证了进行喷嘴配汽优化对机组安全性的影响及解决方案,得出结论:复合配汽方式对机组经济性影响较大,应改为喷嘴配汽。%Discuss the composite steam distribution mode for steam turbine,analyze throttle governing effect mecha-nism of economics,demonstrate the nozzle steam distribution optimization effect on the unit safety and solution,reach deci-sion:composite steam distribution mode has a great economics effect on steam turbine,should be convert to nozzle steam distribution.

  19. Influence of Steam Turbine Valve Discharge Characteristics on Power Systems and Its Control Strategy%汽轮机阀门流量特性对电力系统的影响及其控制策略

    Institute of Scientific and Technical Information of China (English)

    盛锴; 刘复平; 刘武林; 寻新; 王伯春; 李劲柏

    2012-01-01

    汽轮机阀门流量特性是影响电力系统稳定性的重要因素,通过建立电网汽轮机及其调速系统、发电机、励磁系统的数学模型,研究了汽轮机调节阀门流量特性对电网安全稳定性的影响机制。数学分析和仿真结果表明,当汽轮机阀门流量特性不佳时,会引起原动机有功功率的周期性波动。针对此现象,提出了调整后的汽轮机调速系统控制策略,该策略能够抑制功率控制方式下的比例—积分—微分控制器的过度调节,有效增加系统阻尼,抑制原动机的功率波动。%Steam turbine valve discharge characteristics are among the important factors affecting the stability of the power systems.The influence mechanism of steam turbine valve discharge characteristics on the security and stability of the power grid is studied through the mathematical modeling of steam turbine and its speed control system,generator and excitation system.Mathematical analysis and simulation results show that cyclic fluctuations of generator active power might be caused by undesired steam turbine valve discharge characteristics.In view of this phenomenon,a modified control strategy of turbine governor modification system is proposed.This strategy can inhibit the excessive accommodation of proportion-integration-differentiation(PID) controller which is based on the power control mode,effectively increases the system damping,and suppresses power fluctuations of the prime mover.

  20. 基于Apriori关联规则的汽轮机振动监测与故障诊断%Steam Turbine Vibration Based on the Apriori Association Rules Monitoring and Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    刘淑艳

    2012-01-01

    In the power plant steam turbine vibration fault depends only on the vibration parameters of fault diagnosis and diagnostic time is long and the diagnosis of the cause and site specific features, is proposed based on the association rules of steam turbine vibration monitoring and fault diagnosis method. Analysis of the steam turbine vibration fault related to vibration parameters and thermal parameters, on the thermodynamic parameters and vibration parameters associated with the fault diagnosis rules, established the running status monitoring and fault diagnosis system design. Through the actual test proved that this method has very strong practical and feasible, for thermal power plant steam turbine vibration fault of equipment research and development and improvement have draw lessons from a meaning.%针对火电厂汽轮机发生振动故障时仅依靠振动参数进行故障诊断而产生诊断时间长与诊断的原因与部位不具体的问题,提出了基于关联规则的汽轮机振动监测与故障诊断方法;分析了汽轮机振动故障产生时涉及到的振动参数与热力参数,研究了将热力参数与振动参数关联结合的故障诊断规则,确立了状态运行监测与故障诊断的系统设计思路;通过实际验证证明这种方法具有很强的实用型与可行性,对火电厂汽轮机振动故障设备的研发与改进有借鉴意义.

  1. Ultrsonic Phased-array Inspection of Mushroom Shaped Leaf Root of Steam Turbine%汽轮机转子菌形叶根超声相控阵检测

    Institute of Scientific and Technical Information of China (English)

    黄桥生; 陈红冬; 龙毅; 熊亮; 胡彬

    2012-01-01

    The steam turbine is one of the most important rotation equipments in the Nuclear Power Plant,the blade of steam turbine is likely to engender crack in the root position that may eventually affect the safety work of low-pressure rotor.The article mainly introduces ultrsonic phased array technology on methods concerning the blade of steam turbine.It is helpful to master the method on how to judge the defects according to the inspection technique of Mushroom shaped leaf root.The inspection result indicated that present technique had good application effectiveness,and the development of the ultrsonic phased-array technology of blade root had great significance in the area of assuring the safety and reliability of running condition of steam turbine.%汽轮机转子是电厂重要的转动设备,高速旋转可能导致叶片叶根裂纹产生,从而影响到低压转子的安全运行。通过对汽轮机转子菌形叶根超声相控阵检测技术研究,掌握叶根缺陷信号的判断方法。检测结果表明:开发超声相控阵检验技术应用效果良好,在保证电厂汽轮机安全、可靠运行上起了重要的作用。

  2. 接触分析在汽轮机隔板强度计算中的应用%Application of Contact FEM on the Strength Calculation of Steam Turbine Diaphragms

    Institute of Scientific and Technical Information of China (English)

    董成龙; 孙涛; 王晓放; 杨凤珍

    2014-01-01

    介绍了传统经验公式Wahl法和目前普遍采用的有限元数值计算方法,指出在对汽轮机隔板强度进行有限元计算时,设定合理准确的边界条件至关重要。通过对某汽轮机厂的实际隔板模型进行计算对比,表明在处理隔板的支承情况时,采用接触分析有限元法能更准确地计算隔板体的挠度和应力。%As the steam turbines develop to the direction of large capacity and high parameter ,the reliability of steam turbine diaphragms is increasingly drawing attention .This paper has a brief introduction to Wahl method and numerical computation method usually used at present .In the procedure of calculating steam turbine diaphragm ’ s strength,defining reasonable boundary conditions is very important according to the real working status .An actual diaphragm model from one Turbine Works is analyzed in this paper , proving that contact FEM , used to simulate its supporting conditions , can obtain more precise deflection and stress results of the diaphragm body .

  3. Characteristic of Structure in 660 MW UItra-supercriticaI DoubIe-reheat Steam Turbine%660 MW超超临界二次再热汽轮机结构特点

    Institute of Scientific and Technical Information of China (English)

    张晓东; 方宇; 唐清舟; 王建伟

    2015-01-01

    Dongfang Turbine Co.,Ltd. developed a highly efficient ultra-supercritical double-reheat steam turbine with improved thermal efficiency and reduced emissions. In this paper, the characteristic of main structure for 660 MW ultra-supercritical double-reheat steam turbine was introduced. Its technical inheritance, reliability and usability were specifically explained. The unit would also become the first 660 MW double-reheat steam turbine in China.%为了进一步提高效率,节能减排,公司研制了超超临界高参数二次再热汽轮机组。文章主要介绍了公司660 MW高参数二次再热汽轮机结构特点,着重阐述了机组技术继承性、安全可靠性、使用性,该机组也将成为国内首个660 MW二次再热汽轮机组。

  4. Application of Advanced CFD-Methods to the Design of Highly Efficient Steam Turbines%运用现代CFD方法设计高效率的汽轮机(续前期)

    Institute of Scientific and Technical Information of China (English)

    T.Thiemann; A.de Lazzer; M.Deckers

    2003-01-01

    论述了运用现代计算流体动力学(Computational Fluid Dynamics,CFD)技术设计高效率汽轮机的方法,典型应用的实例有全三维叶片级流场、叶片汽封和排汽蜗壳计算.计算结果和实际是相符的.进一步对结构性单元和非结构单元程序的计算结果进行了比较,已证明,非结构单元CFD程序用于复杂形状的流场计算时,结果与实际相当一致,并具有独特的功能.%The present paper involves the application of a modern computational fluid dynamics (CFD) meth-od in the design process of highly efficient steam turbines. The method is applied to typical steam turbine de-sign cases, namely the calculation of the fully three-dimensional flow through steam turbine stages, blade sealsand turbine exhaust hoods. Remarkably good agreement was achieved. Furthermore, the results of structuredand unstructured codes were compared against each other. Excellent agreement was found and the unique abili-ties of an unstructured CFD code to model complex geometries are demonstrated.

  5. Application of Advanced CFD-Methods to the Design of Highly Efficient Steam Turbines%运用现代CFD方法设计高效率的汽轮机

    Institute of Scientific and Technical Information of China (English)

    T. Thiemann; A. de Lazzer; M. Deckers

    2003-01-01

    论述了运用现代计算流体动力学(Computational Fluid Dynamics,CFD)技术设计高效率汽轮机的方法,典型应用的实例有全三维叶片级流场、叶片汽封和排汽蜗壳计算.计算结果和实际是相符的.进一步对结构性单元和非结构单元程序的计算结果进行了比较,已证明,非结构单元CFD程序用于复杂形状的流场计算时,结果与实际相当一致,并具有独特的功能.%The present paper involves the application of a modern computational fluid dynamics (CFD) method in the design process of highly efficient steam turbines. The method is applied to typical steam turbine design cases,namely the calculation of the fully three-dimensional flow through steam turbine stages, blade seals and turbine exhaust hoods. Remarkably good agreement was achieved. Furthermore, the results of structured and unstructured codes were compared against each other. Excellent agreement was found and the unique abilities of an unstructured CFD code to model complex geometries are demonstrated.

  6. Analysis of Thermo Dynamic System and Thermo Ecomony for Nuclear Steam Turbine%核电汽轮机热力系统及热经济性的分析

    Institute of Scientific and Technical Information of China (English)

    冀润景

    2016-01-01

    Based on simplification of outlet mix water enthalpy for collection heater and steam enthalpy in each stage of reheater, this paper established heat balance matrix model ,which can be applied for thermo system calculation of nuclear steam turbine .Based on the adjustment of calculation method which used to be applied for thermal power steam turbine ,this paper established a method which can be applied for nuclear turbine .The practical applicability of both the model and method is verified by the calculation of AP 1000 nuclear steam turbine .%对疏水汇集式加热器出口水焓值和再热器各阶段蒸汽焓值计算进行了简化处理,建立了适用于压水堆核电汽轮机热力系统计算的热平衡矩阵模型;对适用于火电再热机组的功率、热耗变化率计算方法进行了调整,建立了适合核电汽轮机的计算方法;利用AP 1000核电汽轮机作为算例,验证了上述方法的实用性。

  7. 汽轮机叶片汽道的结构模型研究%Study on structural model of steam turbine blade

    Institute of Scientific and Technical Information of China (English)

    曾岳飞; 谌永祥; 钟成明; 江敏; 吴越

    2012-01-01

    As an important part of the steam turbine,blade determines the energy conversion efficiency.The features of the structure of steam turbine blades will be researched in it.And according to the characteristics of blade profile as well as the requirements of STEP issued by ISO, Cubic Uniform Rational B-spline and 2×3 drgee Non-Uniform Rational B-spline will be chosen to build the mathematical model of the blade,which matrix expression is later deduced respectively that prove the continuity of the curve,realize the digital expression for the blades. From the matrix expression, obvious Cubic Uniform Rational B-spline has more advantages than 2×3 drgee Non-Uniform Rational B-spline method,such as less computations ,simple and easy control, etc, which can provide theoretical support for subsequent interpolation algorithms.%叶片作为汽轮机的重要组成部分,决定着能量的转换效率.对汽轮机动叶片的结构特征进行了研究,从叶型的特点,结合国际标准化组织颁布的工业产品数据交换标准的要求,选取了三次均匀有理B样条和2×3次非均匀有理B样条为叶型的数学模型,推导了各自的矩阵表达式,证明了曲线的连续性,实现了叶片的数字化表示.由矩阵表达式可以看出,明显的三次均匀有理B样条比2×3次非均匀有理B样条方法的计算量小、简单和便于控制等,为后续的插补算法研究提供了理论支持.

  8. Research progress of the Superheated Steam Drying Technology

    OpenAIRE

    Shi, Yongchun; Li, Jie; Li, Xuanyou; Zhao, Gaiju; Wu, Maogang

    2012-01-01

    The superheated steam drying technology has lots of advantages such as safe, energy-saving, pollution-free and so on, so it causes more and more extensive concern. The superheated steam drying technology is introduced and its merits and faults are analyzed. The theoretical research progress of the superheated steam drying is summarized and the recent application of the materials including the food, wood, paper, sludge and lignite is stated. In brief, the superheated steam drying technol...

  9. Steam turbine of domestic (ultra) critical unit steam turbine temperature low risk analysis and Suggestions%超(超)临界机组汽轮机蒸汽温度低风险分析及建议

    Institute of Scientific and Technical Information of China (English)

    靖长财

    2012-01-01

    Supercritical (ultra) steam turbine of guohua company steam temperature low risk be analyzed, In The principles of the protection configuration, Protection setting characteristics, rotection setting mode, Protection setting value selection and Operating control measures. To protect the turbine safety operation has certain significance.%从保护配置的原则、保护设置特点、保护设置方式、保护定值选取、运行控制措施等方面,分析国华公司超(超)临界机组汽轮机蒸汽温度低存在的风险,对保护汽轮机安全运行具有一定的借鉴意义。

  10. Effects of superheated steam on the drying of rubberwood

    Directory of Open Access Journals (Sweden)

    Kanokwan Buaphud

    2006-07-01

    Full Text Available Rubberwood drying is the most time and energy consuming step in the processing of wood product. This research studied the effect of superheated steam drying on the drying time required and the physical and mechanical properties of rubberwood after drying. In this study, a cylindrical drying chamber with a length of 1.2 m and a diameter of 0.5 m was constructed and injected with superheated steam. The dimensions of the wood lumber were 1 m × 7.62 cm × 2.54 cm. The wood samples were impinged with alternating cycles of superheated steam and hot air at ratios of 6:1, 4:1 and 1:6 hours until the moisture content was less than 15% dry basis. The conditions inside the chamber were 110ºC and ambient pressure. Continuous superheated steam and continuous hot air were also used for comparisons. The drying rate and the temperature profile for each process were determined.Initial acceptability of the dried wood was conducted using the prong test and visual inspection. Results showed that if the drying rate was too fast, the dried wood did not pass the prong test due to stress buildup. Therefore, an optimum drying condition was developed based on minimizing defects and reducing the drying time. For the optimum condition, the following schedule was carried out: (1 saturated steam at 100ºC was used during the first 4 hours of drying to prevent the wood surface from drying too quickly which would minimize the moisture gradient between the center and wood surface, (2 superheated steam at 105ºC and 110ºC was used in alternating cycle with hot air (80ºC during the main drying stages to rapidly remove the free water and majority of the bound water inside the wood, and (3 hot air was used continuously during the final stages of drying to reduce the relative humidity inside the chamber making it possible for the removal of the residual bound water. This process successfully reduced the drying time to less than 2 days without causing any defects which compared

  11. Explosive Boiling of Superheated Cryogenic Liquids

    CERN Document Server

    Baidakov, V G

    2007-01-01

    The monograph is devoted to the description of the kinetics of spontaneous boiling of superheated liquefied gases and their solutions. Experimental results are given on the temperature of accessible superheating, the limits of tensile strength of liquids due to processes of cavitation and the rates of nucleation of classical and quantum liquids. The kinetics of evolution of the gas phase is studied in detail for solutions of cryogenic liquids and gas-saturated fluids. The properties of the critical clusters (bubbles of critical sizes) of the newly evolving gas phase are analyzed for initial st

  12. Analyses of Temperature Field and Deflection of Steam Turbine IP Inlet Flow Guide%汽轮机中压进汽导流环温度场及变形分析

    Institute of Scientific and Technical Information of China (English)

    王林

    2014-01-01

    IP inlet flow guide is one of the key components in steam turbine,analyses of temperature field and deflection are important when flow guide of steam turbine is designed.Aim at a 600MW sub-critical steam turbine flow guide,a finite element model is developed,methods for calculating the heat transfer coefficients of flow guide surfaces different regions are described,the finite element thermal and structural analyses are performed on the flow guide.Detailed temperature and deflection distributions are determined during the steady operating conditions.The results show that radial temperature gradient is principal,radial deflection of flow guide foot is 1.611 3mm,radial deflection of flow guide with seal is 2.063 6 mm.The used analytic methods can be applied for temperature field and deflection analyses of sub-critical,supercritical and ultra-supercritical steam turbine flow guide,a basis for the bolting analysis and the cooling structural design of steam turbine flow guide is provided.%中压进汽导流环是汽轮机中的关键部件,在设计过程中必须分析其温度场及变形。针对某亚临界600MW汽轮机导流环,建立了有限元模型,介绍了导流环表面不同区域的传热系数计算方法,用有限元法分析了导流环的温度场和变形,得出了在稳态运行工况的详细温度和变形分布。结果表明,导流环温度梯度以径向为主,导流环的最下部径向变形为1.6113mm,导流环安装汽封处径向变形为2.0636mm。所采用的分析方法可以用于分析亚临界、超临界和超超临界汽轮机导流环的温度场和变形,为导流环螺栓分析和冷却结构设计打下基础。

  13. Effect of chloride and sulfate ions in simulated AVT waters on electrochemical corrosion behavior and oxide film characteristics of LP steam turbine materials in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Nakane, Takahiro [Shinshu Univ., Nagano City (Japan). Interdisciplinary Graduate School of Sience and Technology; Goto, Teruyuki [NSK Ltd., Tokyo (Japan); Niu, Li-Bin [Shinshu Univ., Nagano City (Japan). Dept. of Environmental Science and Technology; Takaku, Hiroshi [Shinshu Univ., Nagano City (Japan). Faculty of Engineering

    2010-07-15

    Electrochemical corrosion behavior and film characteristics were investigated in simulated all-volatile treatment (AVT) waters containing both sulfate (SO{sub 4}{sup 2-}) and chloride (Cl{sup -}) for 13Cr, 16Cr-4Ni, 3.5NiCrMoV and high-purity 9CrMoV steels of low-pressure (LP) steam turbines in power plants. Concerning the 13Cr, 16Cr-4Ni and high-purity 9CrMoV steels, the corrosion pit growth proceeded with an increasing content of SO{sub 4}{sup 2-} up to 50 mg x kg{sup -1} in the test water with 100 mg x kg{sup -1} Cl{sup -}, although a SO{sub 4}{sup 2-} concentration above 50 mg x kg{sup -1} in the test water suppressed the corrosion pit growth due to the combined effect of Cl{sup -} and SO{sub 4}{sup 2-}. No corrosion pits occurred for 3.5NiCrMoV steel, which showed predominantly general corrosion in the test waters with Cl{sup -} and SO{sub 4}{sup 2-}. It is concluded that both the heat-treatment-improved 16Cr-4Ni steel for blades and the newly developed high-purity 9CrMoV steel for rotors have a high resistance to pitting corrosion. (orig.)

  14. 超超临界二次再热汽轮机发展综述%Development of Ultra-supercritical Double-reheat Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    王建录; 张晓东

    2016-01-01

    文章概述了汽轮机二次再热技术的发展历程,当前我国超超临界二次再热汽轮机技术研发情况,并重点介绍了我国首台超超临界二次再热汽轮机技术特点及运行情况,对未来二次再热汽轮机技术发展方向和典型机型进行了探讨。%This paper introduces the evolution of double-reheat turbine technology, the development of the ultra-supercritical double-reheat turbine technology in China,and mainly introduces the technical charateristic and operation conditions of the first ultra-super⁃critical double-reheat turbine unit made by DTC in China. The new development direction and typical models of the double-reheat steam turbine designed by DTC is discussed in this paper.

  15. 汽轮机润滑油系统进水的治理%Management of water power plant steam turbine lubricating oil system

    Institute of Scientific and Technical Information of China (English)

    刘炜

    2014-01-01

    Combined with the moisture content of steam turbine lubricating oil exceed the standard phenomenon during the operation of the power plant, expounds the harm of water turbine lubricating oil system and cause water causes, introduces the reason of turbine shaft seal leakage, proposed to prevent water in lube oil system and reduce the lubricating oil system measures the moisture content, the favorable effect.%结合本电厂运行过程中出现的汽轮机润滑油水分含量超标现象,阐述了汽轮机润滑油系统进水的危害和引起进水原因,介绍了汽轮机轴封漏气的原因,提出了防止润滑油系统进水和降低润滑油系统中水分含量的具体措施,经过实施后效果良好。

  16. Physical-chemistry aspects of water in steam turbines associated with material stress and electrochemical assessment of the AISI 403 to simulate real condition

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, D.S.; Franco, C.V.; Godinho, J.F.; Frech, W.A.; Sonai, G.G. [Univ. Federal de Santa Catarina, Florianopolis (Brazil); Torres, L.A.M.; Ellwanger, A.R.F. [Tractebel Energia, Capivari de Baixo (Brazil)

    2009-07-01

    This study described a methodology developed to prevent the occurrence of corrosion failure in steam turbines. The methodology was developed after the failure of a turbine blade at a plant in Brazil. Deposits were collected from various locations along the turbine blade path and analyzed. A turbine deposit collector and simulator was installed to determine the concentrations of steam impurities. Samples were collected from the low pressure turbine at the crossover point and from the polishing station and analyzed using inductive coupled plasma-mass spectrometry (ICP-MS) in order to determine if sodium levels exceeded 3 ppb. Filters were weighed in order to determine the accumulation of impurities. A 3-electrode system was used to determine the influence of chloride ions. The design of the system's condensate polisher beds was modified in order to improve condensate effluent conductivity. The condensate treatment procedure lowered the concentrations of salt impurities and established a monitoring methodology for water and steam used at the plant. It was concluded that the methodology can be used to to reduce inspection intervals and increase system reliability. 10 refs., 1 tab., 7 figs.

  17. Correction Method about the Working Condition Graph of the Heating Steam Turbine System and Parameter%供热式汽轮机工况图的系统及参数修正方法

    Institute of Scientific and Technical Information of China (English)

    李勇; 吕泰萍; 王占洲

    2015-01-01

    Working condition of the heating steam turbine figure in existence,is mainly obtained in the rated parameters of main steam and reheat steam parameters,the exhaust steam parameters and the extraction steam pressure,and thinking of the regenerative system state is normal.While in the actual operation of the steam turbine,these parameters are not always keep their rating unchanged,regenerative system status also inevitably deviate from the design values,and there is also the reduction temperature of superheater and reheater.At this moment, In order to get the relationship among the electrical power and the main steam flow and the amount of extraction,we can' t pick up the operation condition of the steam turbine diagram directly,and must correct it.This paper give a modified method about the regenerative system states,main steam turbine parameters,regenerative system parameters,the reheat steam temperature,steam turbine exhaust steam pressure and extraction steam pressure deviating from the value of the design,and process the correct calculation with a certain C330/262-16.7/0.49/538/538 type steam turbine as an example.The proposed correction method also has a certain guiding significance of predicting steam turbine electric power according to the main steam flow and extraction steam flow in the actual operation.%现有的供热式汽轮机工况图,主要是在额定的主蒸汽参数、再热蒸汽参数、排汽参数及抽汽压力下得到的,并且认为回热系统的状态正常.而汽轮机实际运行中,这些参数并不总是保持其额定值不变,同时回热系统状态也不可避免地要偏离设计值,且还存在着过热器和再热器的喷水减温.此时,为了得到电功率与主蒸汽流量及抽汽量之间的关系,就不能直接查取汽轮机的工况图,而必须对其进行修正.给出了在汽轮机回热系统状态及主蒸汽参数、再热蒸汽温度、汽轮机排汽压力以及抽汽压力偏离设计值时的

  18. Effective Parameters on Performance of Multipressure Combined Cycle Power Plants

    OpenAIRE

    Thamir K. Ibrahim; Rahman, M M

    2014-01-01

    A parametric analysis is performed for numerous configurations of a combined cycle gas turbine (CCGT) power plant, including single-pressure, double-pressure, triple-pressure, triple-pressure with reheat, and supplementary triple-pressure with reheat. The compression ratio of the gas turbine and the steam pressure of the steam turbine are taken as design parameters. The thermodynamic model was developed based on an existing MARAFIQ CCGT power plant and performance model code developed using t...

  19. Superheated Droplet Detector Response for Temperature

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Superheated droplet detector has the following advantages: Used repeatedly, recording the cumulative dose, using both indoors and outdoors, compacting; relatively low cost, direct reading of the bubbles using the naked eye, and working in gamma-neutron mixed-field well

  20. Standardisation of superheated drop and bubble detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vanhavere, F.; D' Errico, F

    2002-07-01

    This study presents an analysis of the commercially available superheated drop detectors and bubble detectors, performed in substantial accordance with the guidelines developed by the International Organisation for Standardization (ISO). The analysis was performed in terms of linearity, reproducibility, ageing, minimum detection thresholds, energy and angular dependence of the response and the influence of various climatic conditions. (author)

  1. Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Naradasu

    2007-01-01

    Full Text Available Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

  2. Generating power at high efficiency: combined cycle technology for sustainable energy production

    Energy Technology Data Exchange (ETDEWEB)

    Jeffs, E.

    2008-04-15

    The book reviews key developments in combined cycle technology; gives examples of plants around the world; and looks at how combined cycle technology can evolve to meet future energy needs. Contents are: Introduction; Brief history of development; Some early schemes; Gas turbine developments; Steam generator concepts; The single shaft block; Repowering steam turbines; Combined heat and power; Gas turbines and coal; and What does the future hold?

  3. 基于Aspen Plus的蒸汽透平网络模拟和优化%Simulation and optimization of steam turbine network with Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    马琳瑛; 赵亮; 李泽秋; 钱锋

    2012-01-01

    According to the unreasonable phenomena in the steam piping network of ethylene plant, the steam turbine network of the device is simulated and optimized by the chemical process software, Aspen Plus. The influence of operating condition change on turbine efficiency is discussed through simulation of the turbine, such as extraction steam flow, into steam temperature, exhaust steam pressure. Based on the results, the steam turbine network is simulated and optimized by particle swarm optimization through the interface toolkit MAP, while extraction steam flow for independent variable and the total into steam flow for target variables. Using intelligent algorithm, the defect of model's not easy to converge is avoided, which is caused by setting too much constraints as Design Regulations in Aspen Plus. The optimization results show that in the condition of meeting the same output power and the requirement of the other pipe networks, the steam consumption of supper-high-pressure (SS) could be reduced effectively by selecting the extraction capacity of every turbine reasonably. The turbine network optimized could decrease 0.6 ton SS consumption per hour.%针对乙烯装置蒸汽管网用能过程中存在的不合理现象,采用Aspen Plus化工流程软件对其中的蒸汽透平网络进行了模拟和优化.通过对单个透平的模拟,分析了透平抽汽量、进汽温度和排汽压力等操作条件的变化对透平效率的影响.在此基础上模拟了蒸汽透平网络,并以透平抽汽量为自变量、透平网络总进汽量为目标变量,通过MATLAB-Aspen Plus接口工具箱使用粒子群优化算法(PSO)对其进行操作参数优化.采用智能算法,避开了因在Aspen Plus中设置过多约束作为设计规定而导致模型不易收敛的不足;对于约束条件的处理,通过对不满足约束的粒子加以惩罚来实现.优化结果表明,在满足透平输出功率以及低等级管网蒸汽用量需求的前提下,通过合理分

  4. Fatigue test results of the rotating steel blades of steam turbine K-25-0.6 GEO with ion-plasma coating

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Arkad'ev, D. A.; Temkin, S. G.; Senina, N. A.

    2016-12-01

    Fatigue test results of the rotating steel blades of the fourth stage of the K-25-0.6 low pressure cylinder Geo steam turbine manufactured in the Kaluga Turbine Plant (hereinafter, KTP) with the ion-plasma coating were presented. Coating formation was carried out at the National Research University (MPEI) on the Gefest vacuum pilot plant by the magnetron sputtering method. Characteristics of the obtained coating were analyzed with the use of the scientific-research equipment of the National Research University (MPEI). Fatigue tests of the rotating blades and determination of the fatigue strength of the material with the ion-plasma coating were carried out on the electrodynamic vibration machines VEDS-400A in the KTP structural laboratory. The following characteristics were obtained after tests: Ti-TiN composition, 10-11 μm thickness, 1200 HV 0.05 microhardness. Fatigue tests showed that destruction, regardless of availability or nonavailability of the coating, took place by cross-section in the root zone both on the leading and trailing edges of the blade, i.e., in the most stressed zones. It was found out that the maximum stresses during tests were revealed in the root section along the trailing edge on the blade pressure side, and the less stresses were on the leading edge. Fatigue strength of the working blades after coating formation increased by 12% minimum. Results of the fatigue tests prove the previously obtained data concerning 10-12% increase of the fatigue strength of the blade steel with the ion-plasma coating and allow claiming that the process of their formation exerts the positive influence on the fatigue characteristics of the blade materials.

  5. Simulation Study of a New Method to Synchronously Control Rotate Speed and Power of a Steam Turbine%汽轮机转速与功率同步控制新方法的仿真研究

    Institute of Scientific and Technical Information of China (English)

    史小平; 王子才

    2003-01-01

    经典的汽轮机调节系统在实现功率跟踪负荷变化的同时会不可避免地引起转速的变化,从而引起电网频率的变化.应用线性系统极点配置的方法,提出了一种既能使汽机功率跟踪负荷,同时又能对汽机转速按指令曲线进行控制的新方法.用这种方法设计的调节系统就能省去二次调频的环节.计算机仿真的结果证明了本文所提出方法的正确性和有效性.%The frequency of the electric network will inevitably fluctuate because of rotate speed variation of a steam turbine, while its classical regulation system is accomplishing matching between its power and the referenced electric load. A new method is developed to synchronously control rotate speed and power of a steam turbine with pole placement technique of linear system. With this new control method, not only the rotate speed of a steam turbine can be controlled according to its instruction curve, but also its power can be synchronously controlled to quickly track the electric load without additional component of the frequency regulation. The computer simulation verifies the correctness and the effectiveness of the presented new control method.

  6. Research on Dynamic Behavior of Frame Foundation for Large-Scale Steam Turbine-Generator Set%大型汽轮发电机组框架式基础的动力特性研究

    Institute of Scientific and Technical Information of China (English)

    梅德庆; 何闻; 沈润杰; 陈子辰

    2001-01-01

    In this paper, the dynamic model building of frame foundation for large-scale steam turbine generator set is performed by substructure method. All the major components of frame foundation, including deck, piers, foundation mat, and soil medium, have been included. Deck and piers are treat ed as 3-D beam element, foundation mat is treated as elastic thin plate and simulated by approximate solution of Ritz function. Furthermore, FFAS software package is developed on the basis of the dy namic model, internal characteristics and dynamic response of frame foundation for a 600MW steam turbine-generator set are analysed by FFAS. And some important results are concluded, which is of some value to the design of frame foundation for large-scale steam turbine generator set. Figs 8, ta bles 2 and refs 8.%对大型汽轮发电机组框架式基础利用子结构法进行了动力学建模分析。平台、立柱框架部分采用梁 单元进行离散化,基础底板则采用弹性薄板的Ritz函数近似解来模拟,从而有效地解决了基础与地基的边界 接触问题。根据该动力学模型编制了FFAS框架式基础动力特性分析软件,并对国内某电厂的1台600MW 汽轮发电机组框架式基础进行了动力特性分析计算,并得出了结论。图8表2参8

  7. Study on Optimization of DEH Control System Based on DCS Steam Turbine%基于DCS汽轮机DEH控制系统的优化研究分析

    Institute of Scientific and Technical Information of China (English)

    刘婧艳

    2012-01-01

    Digital electro-hydraulic control system(DEH) is the application of DCS control system in steam turbine control typical form, and the turbine is almost always uses the DEH control system to realize the control function. With the DCS control system and the rapid development of progress, on steam turbine DEH control system implementing the optimization measures also be imperative. The article complies with the development of science and technology requirements, based on the combination of DCS steam turbine DEH control system 's actual situation, the system optimization of relevant analysis and research, in order to realize the control function of the system of comprehensive optimization.%数字电液调节控制系统(DEH)是DCS控制系统应用于汽轮机控制的典型形式,而且当前的汽轮机几乎都是运用DEH控制系统来实现其有关的控制功能.随着DCS控制系统的迅速发展及进步,对汽轮机DEH控制系统实行相关的优化措施也势在必行.本文顺应科技发展的要求,结合基于DCS下汽轮机DEH控制系统的实际情况,对其系统的优化进行相应的分析和研究,以实现系统控制功能的全面优化.

  8. A superheated Bose-condensed gas

    OpenAIRE

    Gaunt, Alexander L.; Fletcher, Richard J.; Robert P. Smith; Hadzibabic, Zoran

    2012-01-01

    Our understanding of various states of matter usually relies on the assumption of thermodynamic equilibrium. However, the transitions between different phases of matter can be strongly affected by non-equilibrium phenomena. Here we demonstrate and explain an example of non-equilibrium stalling of a continuous, second-order phase transition. We create a superheated atomic Bose gas, in which a Bose-Einstein condensate (BEC) persists above the equilibrium critical temperature, $T_c$, if its coup...

  9. Effect of composition, heat treatment and processing technologies on the microstructure and properties of HP and IP rotors of large steam turbines from 1CrMoV steels

    Energy Technology Data Exchange (ETDEWEB)

    Tchizhik, A.A. [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plant Equipment, St. Petersburg (Russian Federation)

    1998-12-31

    In the presentation the evolution of the technology manufacturing of the large forging from the 1CrMoV steels and the results complex of the long time investigations rotors on virgin state and after different operation times is analyzed. Among the information there are the criterion of the optimization of the composition steel service properties, especially super long - term creep resistance, creep fracture and long time cracks resistance. Two safety coefficients: stress (SSC) and time safety coefficient (TSC) must be used for calculations of the possibility prolongation service life of HP and IP rotors for large steam turbines. (orig.) 11 refs.

  10. Causes of the Impact of Water Jet Air Ejector to Steam Turbine Vacuum and the Treatment%射水抽气器影响汽轮机真空的原因及处理

    Institute of Scientific and Technical Information of China (English)

    汪翠凤

    2011-01-01

    针对一台25MW汽轮机组真空系统的特点,通过一次事故原因的查找,分析了因射水抽气器工作状况不良而引起的真空下降的原因,并提出了处理方法.%Aiming at the characteristics of vacuum system of 25MW steam turbine, through the search for cause of the accident, the causes of vacuum down caused by poor working conditions of water jet air ejector are analyzed, and the treatment methods are proposed.

  11. 300MW及以上汽轮机低压转子冶炼工艺研究%Smelting Process of Steam Turbine Low Pressure Rotor of 300 MW & Above

    Institute of Scientific and Technical Information of China (English)

    魏雪晴; 李奇; 管仲毅

    2014-01-01

    介绍了300 MW及以上汽轮机低压转子的冶炼工艺控制要点。对耐火材料和辅具进行了改进和优化,最终生产出合格的转子锻件。%This paper presents the smelting process control key points of 300 MV and above steam turbine low pressure rotor .Refractory materials and auxiliary tools have been improved and optimized , eventually acceptable rotor has been produced .

  12. Analysis and control of erosion by solid particles in the elements of the flow system of steam turbines; Analisis y control de erosion por particulas solidas en los elementos del sistema de flujo de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Mazur Czerwiec, Zdzislaw; Campos Amezcua, Alfonso; Campos Amezcua, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2010-07-01

    The analysis of erosion by solid particles is presented of different elements of the flow channel of the steam turbines that operate in Mexico: nozzles, stop valves, blade bosses, labyrinth seals and rotor disc; using tools of of Computational Fluid Dynamics (CFD). In these main elements of turbines a strong problem of erosion was registered that threatens the reliable operation of the turbines, its availability and its optimal yield. With base on the results of the numerical analyses, the design modifications of the different elements were developed from the flow channel of the steam turbines, in order to reduce the erosion and thus diminishing the energy losses and increasing the steam turbine efficiency. This work presents the main benefits that the Thermoelectric Power Plants obtain with the reduction of the erosion by solid particles that affect the critical components of steam turbines: extension of the period between maintenance, replacement of components, reduction of operation and maintenance costs of the turbines, and extension of the useful life of the main components. [Spanish] Se presenta el analisis de erosion por particulas solidas de diferentes elementos del canal de flujo de las turbinas de vapor que operan en Mexico: toberas, valvula de paro, tetones de los alabes, sellos de laberinto y disco del rotor; utilizando herramientas de Dinamica de Fluidos Computacional (DFC). En estos elementos principales de turbinas se registro un fuerte problema de erosion que amenaza la operacion confiable de las turbinas, su disponibilidad y su rendimiento optimo. Con base en los resultados de los analisis numericos, se desarrollaron las modificaciones de diseno de los diferentes elementos del canal de flujo de las turbinas de vapor, con el proposito de reducir la erosion y asi, disminuir las perdidas de energia e incrementar el rendimiento de las turbinas de vapor. Este trabajo presenta los principales beneficios que obtienen las Centrales Termoelectricas con la

  13. Improvement and Application of Nuclear Steam Turbine Shafting Differential Expansion Dynamic Monitoring Technology%核电汽轮机轴系胀差动态监控技术改进与应用

    Institute of Scientific and Technical Information of China (English)

    高伟; 李庆华; 孙振平

    2016-01-01

    As the problem of the nuclear half-speed steam turbine axial displacement and shafting differential expansion excessive during commissioning and operation period happened several times in a nuclear power plant project , it directly affects the safe and stable operation of the unit .Based on the analysis and research on the relationship between axial displacement ,shafting differential expansion , absolute expansion and “zero” value of the rotor of this type nuclear steam turbine,according to the relevant design document about the unit operation program ,combined with the actual installation and commissioning process monitoring data of the turbine shafting , the analysis and control method of the steam turbine shafting differential expansion ,axial displacement and absolute expansion are determined .Solved the problem of the shafting differential expansion ,axial displacement ,absolute expansion and “zero” position of this type nuclear steam turbine ,realized the reliable monitoring and protection of the unit .%针对国内某核电项目半速汽轮机在调试、运行期间多次发生转子轴向位移和胀差超标问题,直接影响机组安全、稳定运行。通过对该型式汽轮机转子轴向位移、胀差、绝对膨胀与“零”值关系分析和研究,依据相关设计运行程序文件,结合现场汽轮机转子轴系实际安装、调试过程监控数据,确定了汽轮机转子胀差、轴向位移及绝对膨胀变化分析和控制方法。解决了该型式核电汽轮机转子胀差、轴向位移、绝对膨胀及定“零”位等问题,实现了对机组的可靠监视和保护。

  14. AnaIysis of SIiding Key System for Dongfang Independent NucIear Steam Turbine%东方自主核电汽轮机滑销系统分析

    Institute of Scientific and Technical Information of China (English)

    卢平; 高宏喜

    2014-01-01

    The paper analyzed the sliding key system for Dongfang independent nuclear power steam turbine, emphatically enumerated the emphasis in design process, and checked the strength of dead keys and guiding keys in larger seismic loads and extreme steam thrust operating conditions.%文章分析了东方自主核电汽轮机的滑销系统,着重列举了设计过程中的重点,在较大地震载荷及极限工况蒸汽推力下进行了主机部件死点键、导向键的强度校核。

  15. Performance Monitoring and Fault Diagnosis of Wet-steam Turbines for Nuclear Power Plants%核电站汽轮机运行性能监测与诊断

    Institute of Scientific and Technical Information of China (English)

    邓德兵; 赵清森; 陈伟; 刘刚

    2011-01-01

    就核电汽轮机与火电汽轮机的差异以及由此差异引起的湿蒸汽汽轮机通流性能表征与热平衡计算的难点进行了论述,提出了利用特征通流面积CFA来表征核电汽轮机的通流性能和采用小误差热平衡法来计算核电汽轮机的热平衡图,应用小误差热平衡法和特征通流面积成功开发了核电站热力性能在线监测与分析系统和核电站汽轮机全面热力试验计算软件,并将这两项技术应用在大亚湾核电机组热力性能在线监测与分析系统和岭澳二期核电机组全面热力试验中.结果表明:实际运行监测中特征通流面积监测值的测量精度可控制在1%以内.%An introduction is being presented to differences between nuclear and thermal power steam turbines,together with a description to the consequent difficulties in flow performance characterization and heat balance calculation.The concept of characteristic flow area(CFA) and the method of slight error heat balance(SEHB) are proposed to respectively characterize the flow performance and carry out relevant thermal calculations for nuclear power steam turbines,with which a series of software are developed for on-line performance monitoring/analysis and thermal calculation purposes.The two developed technologies have been applied to on-line performance monitoring/analysis of steam turbine in Daya Bay Nuclear Power Plant and to thermal performance test of steam turbine in Lingao Phase II Nuclear Power Plant.Actual operation results show that the measurement of CFA can be controlled within an accuracy of 1%.

  16. 基于火电站汽轮机标准化安装过程的动态仿真研究%Dynamic Simulation Research Based on the Steam Turbine Standardization Installation Process of Power Plant

    Institute of Scientific and Technical Information of China (English)

    李少华; 张庆喆; 车德勇; 王虎

    2013-01-01

    随着电力工业的快速发展,600MW和1 000MW等大型火电机组越来越多,并已成为主力发电机组,针对大型火电站汽轮机安装过程的复杂性,利用三维可视化仿真技术对整个火电站汽轮机安装过程进行三维动态仿真,并辅以图形、语音、文字等多媒体方式说明施工过程中的施工方法、施工工艺、技术标准等,构建汽轮机安装过程标准化方案,开发“火电站汽轮机建设过程仿真系统”.系统的开发对于汽轮机施工行业确定科学的施工方法、运用先进的工艺技术以及培养高素质的施工队伍具有重要的意义,并极大地促进了汽轮机施工行业的科技进步.%Following the rapid development of the power industry,600MW and 1000MW thermal power units are more and more,and has become the main generator sets,Aiming at the complexity of the installation process for steam turbine,3-D visualization techniques was used dynamic simulation of the entire power plant steam turbine installation process,Supplemented by graphics,voice,text and other multimedia means that every installation process of the construction method,construction technology,technical standards etc,Building thermal power station civil construction process standardizationconstruction scheme,Development the steam turbine installation process of 3-D visualization dynamic simulation system.The development of the system for steam turbine construction industry determine scientific construction method,using advanced technology and cultivate high-quality construction team has an important meaning,and greatly promoted the turbine construction industry science and technology progress.

  17. Effect of Gas Turbine Exhaust Temperature, Stack Temperature and Ambient Temperature on Overall Efficiency of Combine Cycle Power Plant

    OpenAIRE

    Khan, M N; K.P.Tyagi

    2010-01-01

    The gas turbine exhaust temperature, stack temperature and ambient temperature play a very important role during the predication of the performance of combine cycle power plant. This paper covers parametric analysis of effects of gas turbine exhaust temperature, stack temperature and ambient temperature on the overall efficiency of combine cycle power plant keeping the gas turbine efficiency as well as steam turbine efficiency constant. The results shows that out of three variables i.e. turbi...

  18. Coupling of Modular High-Temperature Gas-Cooled Reactor with Supercritical Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Shutang Zhu

    2008-01-01

    Full Text Available This paper presents investigations on the possible combination of modular high-temperature gas-cooled reactor (MHTGR technology with the supercritical (SC steam turbine technology and the prospective deployments of the MHTGR SC power plant. Energy conversion efficiency of steam turbine cycle can be improved by increasing the main steam pressure and temperature. Investigations on SC water reactor (SCWR reveal that the development of SCWR power plants still needs further research and development. The MHTGR SC plant coupling the existing technologies of current MHTGR module design with operation experiences of SC FPP will achieve high cycle efficiency in addition to its inherent safety. The standard once-reheat SC steam turbine cycle and the once-reheat steam cycle with life-steam have been studied and corresponding parameters were computed. Efficiencies of thermodynamic processes of MHTGR SC plants were analyzed, while comparisons were made between an MHTGR SC plant and a designed advanced passive PWR - AP1000. It was shown that the net plant efficiency of an MHTGR SC plant can reach 45% or above, 30% higher than that of AP1000 (35% net efficiency. Furthermore, an MHTGR SC plant has higher environmental competitiveness without emission of greenhouse gases and other pollutants.

  19. Analysis and Optimization of a Compressed Air Energy Storage—Combined Cycle System

    OpenAIRE

    Wenyi Liu; Linzhi Liu; Luyao Zhou; Jian Huang; Yuwen Zhang; Gang Xu; Yongping Yang

    2014-01-01

    Compressed air energy storage (CAES) is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional CAES combined with a steam turbine cycle by waste heat boiler. Simulation and thermodynamic analysis...

  20. THE DETECTION OF THE NECESSARY CONDITIONS OF EFFECTIVE FUNCTIONING OF THE BALL CLEANING SYSTEM OF THE TUBES OF STEAM TURBINE CONDENSERS. Part 1

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2017-01-01

    Full Text Available A problem of an increase of the power of turbine by improving heat transfer in condensers of steam turbines is considered in the article as a topical one. The analysis of contamination of the internal surfaces of cooling tubes and of the influence of pollution on the process of heat transfer in turbine condensers has been fulfilled. The existing method of cleaning of condenser tubes with the use of porous elastic balls of sponge rubber that is implemented on a number of large thermal power plants and state region power plants of the Republic of Belarus is examined. In the operation of the ball cleaning system a significant drawback has been revealed, viz. a low efficiency of this method due to the failure to comply with preparation the system of circulating water for operation. Also, a certain imperfection of ball cleaning system technology has been determined. One of the prerequisites for the effective functioning of the ball cleaning system is a certain degree of purity of the pipe system of the condenser, characterized by the coefficient of purity. To determine the effectiveness of ball cleaning system a series of experiments on the launching of porous rubber balls in the pipe system of the main and the embedded bunches of the T-250/300-240 UTMZ turbine has been produced. Immediately before the experiments hydraulic cleaning of the tubes of the condenser by a high-pressure installation were carried out. During the experiments, records of the number of downloaded porous rubber balls, of the number of rubber balls captured in a loading chamber, and of the number of rubber balls that remained in a calibration device were kept. A large proportion of default of the balls caused by the presence of residues of the carbonate sediments, that obstruct the movement of porous rubber balls in the tubes of the condenser, was determined. The presence of carbonate deposits in the tubes of the condenser indicates a lack of effectiveness of antiscale treatment

  1. 200 MW汽轮机多背压运行的热经济性分析%An Analysis of the The rmodynamic Effectiveness of a 200 MW Steam Turbine with Mu ltiple Back-pressure Operation

    Institute of Scientific and Technical Information of China (English)

    李勇; 曹祖庆

    2001-01-01

    通过对某200 MW汽轮机采用三背压凝汽器运行相对于单压运 行的凝结水温度、1号低压加热器抽汽量、各排汽缸最末级相对内效率及整机功率的变化 情况的计算,定量分析了200 MW汽轮机采用三背压运行的经济性,并给出了200 MW汽轮机采 用三背压运行冷却水温应满足的条件。%A calculation was conducted of the variation of parameters when a 200 MW steam t urbine employs a triple back-pressure condenser instead of a single back-press ur e one. Such parameters include the condensate temperature, the steam extraction rate of No.1 low-pressure heater, the relative inner efficiency of the last sta g e of various exhaust cylinders and the power output of the turbine unit as a who le. On this basis a quantitative analysis was performed of the thermodynamic eff ectiveness of the 200 MW steam turbine employing the triple back-pressure conde n ser. In addition, also given are the cooling water temperature requirements to b e met by the above-mentioned 200 MW steam turbine unit.

  2. The Calculation of the Steam Turbine Governing Stage Enthalpy Drop and Reaction Degree in Off-design Condition%汽轮机调节级变工况时焓降和反动度的计算

    Institute of Scientific and Technical Information of China (English)

    李清; 黄竹青; 王运民; 李亮; 张伦柱

    2012-01-01

    The calculation of enthalpy drop and reaction degree is an important content and basis of the calculation for governing stage in off-design condition. The calculation method of the steam turbine governing stage enthalpy drop and reaction degree in off-design condition is introduced in this paper, and a instance calculating of a power plant - N600 - 16.67 -538 / 538 -1 steam turbine in Hunan province is simulated by MATLAB software. Finally,the changing curves of governing stage enthalpy drop and reaction degree is drawn according to the calculation results. The results from the research have an important value in theory and application.%调节级焓降和反动度的计算是调节级变工况计算的基础和重要内容.介绍了汽轮机调节级变工况时焓降和反动度的计算方法,并以湖南某电厂N600-16.67 -538/538 -Ⅰ型汽轮机为例,应用MATLAB语言编制计算软件进行了实例计算,根据计算结果绘制了调节级焓降和反动度的变化曲线.研究成果具有重要的理论意义和应用价值.

  3. Selection of Materials for Critical Parts of 650 ℃ USC Steam Turbines%650℃等级超超临界汽轮机关键部件选材

    Institute of Scientific and Technical Information of China (English)

    彭建强

    2016-01-01

    The present study for high temperature materials of 650 ℃ USC steam turnbines is described .By analyzing the development process of materials used at 650 ℃ condition and the property requirements for critical parts of steam turbines ,the selection of the materials for critical parts is proposed ,then ,the existing problems are discussed .It is concluded that the research for heavy forgings and castings materials as well as related process property is the key issues on the materials for critical parts of 650 ℃ USC steam turbines .%介绍了国内外650℃等级超超临界汽轮机高温材料的最新研究情况。通过分析650℃等级材料的发展过程、汽轮关键部件对材料性能的要求等,给出了650℃等级超超临界汽轮机关键部件选材,并对存在的问题进行了分析讨论,表明大型铸锻件材料研究及相关工艺性能研究是650℃机组超超临界汽轮机关键部件选材的核心。

  4. The Retrofit of Steam Seal for 600MW Steam Turbine and Its Control Measures for the Starting Risk%600 MW汽轮机汽封改造及启动风险控制措施

    Institute of Scientific and Technical Information of China (English)

    覃恒锋

    2013-01-01

    Many power plants retrofit steam seal of steam turbine in order to reduce the steam leakage, reduce the rate of heat loss, increase the heat efficiency of the unit and its coefficient of the safe operation. The paper introduces the content and principle of steam seal retrofit of steam turbine in 600MW supercritical unit power plant, and puts forward control measures for the risk of starting the unit for the similar power plants.%  为了减少漏气,降低机组热耗率,提高机组热效率,增加机组安全运行系数,许多电厂对汽轮机汽封进行改造。文章介绍了600 MW超临界机组电厂汽轮机汽封改造的内容和原理,并提出了机组启动风险控制措施,为同类电厂提供借鉴。

  5. Body Structure and Design Feature of DTC New UItra-supercriticaI 1 000 MW Steam Turbine%东方新超超临界1000 MW汽轮机本体结构及设计特点

    Institute of Scientific and Technical Information of China (English)

    刘雄; 袁永强; 黄果; 高展羽

    2015-01-01

    文章详细介绍了东方新一代超超临界1000 MW汽轮机的本体结构及设计特点。该机型是东方采用现代汽轮机技术自主研发而成的一种新型高参数汽轮机,通过重要结构的优化设计以及高温材料的合理选择,有效地提高了机组的经济性与可靠性。%The body structure and design feature of DTC new ultra-supercritical 1 000 MW steam turbine are introduced in details. The unit is a new high-parameter and self-developed turbine by DTC. These products are based on modern steam turbine tech-nologies.The reliability and economy of turbine are improved effectively through the optimization design of structure and the reason-able selection of high temperature material.

  6. 汽机房降温通风系统经济性分析%Analysis on the economy of ventilation cooling system of the steam-turbine house

    Institute of Scientific and Technical Information of China (English)

    沈艳; 张晓琼

    2015-01-01

    研究了汽机房不同降温通风方式(蒸发冷却、压缩式制冷、吸收式制冷等降温通风方式)的基本原理,结合实际工程案例,对各降温通风方式进行了设备选型,分析了各种方案的节能及经济性,为火电厂汽机房降温通风设计提供参考。%The paper studies basic principles of various ventilation cooling techniques of the steam-turbine house including evaporative cooling, compression refrigerating,absorption refrigeration and other cooling ventilation methods,carries out facilities selection of cooling ventilation meth-ods by combining with actual engineering examples,and analyzes their energy conservation and economy,which has provided some guidance for cooling ventilation design of the steam-turbine house of the thermal power plant.

  7. Micro Steam Turbine Proportional Valve Control Unit Retrofit Analysis%小汽轮机比例阀驱动控制单元技术改造分析

    Institute of Scientific and Technical Information of China (English)

    冯康

    2013-01-01

    针对华能国际电力股份有限公司上安电厂350 M W机组小汽轮机调速系统在遇到外界干扰时,汽包水位难以控制的问题,提出小汽轮机比例阀驱动单元及电源配置改造中的安装施工方案和设备调试方案,分析改造效果,认为改造后比例驱动单元运行情况良好,小汽轮机进汽调门运行稳定。%The micro steam turbine speed control system of Huaneng Power International Inc S.hang′an Power Plant 350 MW unit is difficult to control the water level when encoun-tered outside interference .This paper advances the install construction project of micro steam turbine proportional valve control unit and power configuration ,analyzes reforma-tion effects considers that proportion drive unit operates well ,micro steam control door operates stably .

  8. Influencia de los parámetros de proceso, en el comportamiento del parámetro vibración absoluta en turbinas de vapor. // Influence of process parameters of the behaviour of absolute vibration parameters in steam turbine.

    Directory of Open Access Journals (Sweden)

    F. de la Torre Silva

    2008-01-01

    Full Text Available Este trabajo muestra el estudio realizado en turbinas de vapor de pequeña capacidad de generación de las centralestermoeléctricas cubanas, relacionadas con la influencia estadística entre parámetros de proceso de la turbina, respecto alparámetro vibración absoluta, medidos en las chumaceras de la turbina. Se utilizan las bases de datos de los sistemas demonitoreado on-line de la turbina. Se exponen las relaciones existentes entre los principales parámetros seleccionados paraeste estudio.Palabras claves: Monitorado on-line, Monitorado de la condición, Parámetros de proceso, Vibraciónabsoluta, Turbinas de vapor.______________________________________________________________________________AbstractThis work show the estudy in small steam turbine capacity of generation in cubans thermoelectric power station to relative withstatistical influence between steam process parameters regarding absolute vibration parameter, in the steam housing measurements.Themselves use database as steam on-line monitoring systems. Expose the existing relation between the principal selection parametersfor this study.Key Words: On.line monitoring, Condition monitoring, Process parameters, Absolute vibration, SteamTurbine.

  9. Thermal activation of superheated lipid-coated perfluorocarbon drops.

    Science.gov (United States)

    Mountford, Paul A; Thomas, Alec N; Borden, Mark A

    2015-04-28

    This study explored the thermal conditions necessary for the vaporization of superheated perfluorocarbon nanodrops. Droplets C3F8 and C4F10 coated with a homologous series of saturated diacylphosphatidylcholines were formed by condensation of 4 μm diameter microbubbles. These drops were stable at room temperature and atmospheric pressure, but they vaporized back into microbubbles at higher temperatures. The vaporization transition was measured as a function of temperature by laser light extinction. We found that C3F8 and C4F10 drops experienced 90% vaporization at 40 and 75 °C, respectively, near the theoretical superheat limits (80-90% of the critical temperature). We therefore conclude that the metastabilty of these phase-change agents arises not from the droplet Laplace pressure altering the boiling point, as previously reported, but from the metastability of the pure superheated fluid to homogeneous nucleation. The rate of C4F10 drop vaporization was quantified at temperatures ranging from 55 to 75 °C, and an apparent activation energy barrier was calculated from an Arrhenius plot. Interestingly, the activation energy increased linearly with acyl chain length from C14 to C20, indicating that lipid interchain cohesion plays an important role in suppressing the vaporization rate. The vaporized drops (microbubbles) were found to be unstable to dissolution at high temperatures, particularly for C14 and C16. However, proper choice of the fluorocarbon and lipid species provided a nanoemulsion that could undergo at least ten reversible condensation/vaporization cycles. The vaporization properties presented in this study may facilitate the engineering of tunable phase-shift particles for diagnostic imaging, targeted drug delivery, tissue ablation, and other applications.

  10. Experimental research of heterogeneous nuclei in superheated steam

    Directory of Open Access Journals (Sweden)

    Bartoš Ondřej

    2016-01-01

    Full Text Available A mobile steam expansion chamber has been developed to investigate experimentally homogeneous and heterogeneous nucleation processes in steam, both in the laboratory and at power plants using the steam withdrawn from the steam turbine. The purpose of the device is to provide new insight into the physics of nonequilibrium wet steam formation, which is one of the factors limiting the efficiency and reliability of steam turbines. The expanded steam or a mixture of steam with a non-condensable gas rapidly expands in the expansion chamber. Due to adiabatic cooling, the temperature drops below the dew point of the steam at a given pressure. When reaching a sufficiently high supersaturation, droplets are nucleated. By tuning the supersaturation in the so-called nucleation pulse, particles of various size ranges can be activated. This fact is used in the present study to measure the aerosol particles present in the air. Homogeneous nucleation was negligible in this case. The experiment demonstrates the functionality of the device, data acquisition system and data evaluation methods.

  11. Experimental research of heterogeneous nuclei in superheated steam

    Science.gov (United States)

    Bartoš, Ondřej; Kolovratník, Michal; Šmíd, Bohuslav; Hrubý, Jan

    2016-03-01

    A mobile steam expansion chamber has been developed to investigate experimentally homogeneous and heterogeneous nucleation processes in steam, both in the laboratory and at power plants using the steam withdrawn from the steam turbine. The purpose of the device is to provide new insight into the physics of nonequilibrium wet steam formation, which is one of the factors limiting the efficiency and reliability of steam turbines. The expanded steam or a mixture of steam with a non-condensable gas rapidly expands in the expansion chamber. Due to adiabatic cooling, the temperature drops below the dew point of the steam at a given pressure. When reaching a sufficiently high supersaturation, droplets are nucleated. By tuning the supersaturation in the so-called nucleation pulse, particles of various size ranges can be activated. This fact is used in the present study to measure the aerosol particles present in the air. Homogeneous nucleation was negligible in this case. The experiment demonstrates the functionality of the device, data acquisition system and data evaluation methods.

  12. Graphical procedure for comparing thermal death of Bacillus stearothermophilus spores in saturated and superheated steam.

    Science.gov (United States)

    SHULL, J J; ERNST, R R

    1962-09-01

    The thermal death curve of dried spores of Bacillus stearothermophilus in saturated steam was characterized by three phases: (i) a sharp initial rise in viable count; (ii) a low rate of death which gradually increased; and (iii) logarithmic death at maximal rate. The first phase was a reflection of inadequate heat activation of the spore population. The second and third phases represented the characteristic thermal death curve of the spores in saturated steam. A jacketed steam sterilizer, equipped with a system for initial evacuation of the chamber, was examined for superheat during normal operation. Measurements of spore inactivation and temperature revealed superheat in surface layers of fabrics being processed in steam at 121 C. The high temperature of the fabric surfaces was attributed to absorption of excess heat energy from superheated steam. The superheated steam was produced at the beginning of the normal sterilizing cycle by transfer of heat from the steam-heated jacket to saturated steam entering the vessel.

  13. Dark matter searches using superheated liquids

    Science.gov (United States)

    Manuel, Bou-Cabo; Miguel, Ardid; Ivan, Felis

    2016-07-01

    Direct detection of dark matter is one of the most important topics in modern physics. It is estimated that 22% of universe matter is composed by dark matter in front of 0.4% of ordinary matter like stars, galaxies planets and all kind of known astrophysical objects. Several kinds of experiments are nowadays involved in detection of one of the more accepted particle candidates to be dark matter: WIMPs (Weakly Interacting Massive Particles). These detectors, using several kinds of techniques: Cryogenic semiconductors, scintillation materials like I Na or noble gas chambers among others, are reporting very interesting but inconclusive results. In this paper a review of detectors that are using the superheated liquid technique in bubble chambers in order to detect WIMPs is reported. Basically, we will report about Coupp (Chicagoland observatory for underground particle physics), PICO that is composed by Coupp and Picasso researchers having the aim to build a ton experiment and also about a new detector named MOSCAB (Materia oscura a bolle) that recently published a first results of a test chamber that uses also superheated liquid technique but as a Geyser chamber.

  14. Dark matter searches using superheated liquids

    Directory of Open Access Journals (Sweden)

    Manuel Bou-Cabo

    2016-01-01

    Full Text Available Direct detection of dark matter is one of the most important topics in modern physics. It is estimated that 22% of universe matter is composed by dark matter in front of 0.4% of ordinary matter like stars, galaxies planets and all kind of known astrophysical objects. Several kinds of experiments are nowadays involved in detection of one of the more accepted particle candidates to be dark matter: WIMPs (Weakly Interacting Massive Particles. These detectors, using several kinds of techniques: Cryogenic semiconductors, scintillation materials like I Na or noble gas chambers among others, are reporting very interesting but inconclusive results. In this paper a review of detectors that are using the superheated liquid technique in bubble chambers in order to detect WIMPs is reported. Basically, we will report about Coupp (Chicagoland observatory for underground particle physics, PICO that is composed by Coupp and Picasso researchers having the aim to build a ton experiment and also about a new detector named MOSCAB (Materia oscura a bolle that recently published a first results of a test chamber that uses also superheated liquid technique but as a Geyser chamber.

  15. The Analysis of the Causes of 1000 MW Steam Turbine Bearing Metal Temperature on the High Side and Countermeasures%1000 MW 汽轮机轴承金属温度偏高的原因分析及对策

    Institute of Scientific and Technical Information of China (English)

    靖长财

    2016-01-01

    From the working principle and factors influencing the bearing metal temperature steam turbine bearing ,analyzes the abnormal temperature rise of 1000 MW steam turbine bearing metal four typical cases ,and puts forward the pertinence measures such as operation , maintenance and repair , design, research, for steam turbine safety and reliability operation reference ,in order to avoid high temperature steam turbine bearing metal failure repetitive failure occurred .%从汽轮机轴承工作原理和影响轴承金属温度因素,分析了1000MW汽轮机轴承金属温度异常升高的4次典型案例,提出了运行、检修、设计、研究等针对性措施,为汽轮机安全可靠运行提供参考,以避免汽轮机轴承金属温度高的故障重复发生。

  16. Steam Turbine Materials and Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, G.H.; Hsu, D.H.

    2008-07-01

    Ultra-supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760 °C. In prior years this project examined the steamside oxidation of alloys for use in high- and intermediate-pressure USC turbines. This steamside oxidation research is continuing and progress is presented, with emphasis on chromia evaporation.

  17. Coolants for a closed-cycle cooling system of device for removing the condensation heat of teh waste steam from steam-turbine power plants

    Energy Technology Data Exchange (ETDEWEB)

    Richter, D.; Heeren, H.

    1976-03-25

    A series of demands are made on the coolant for the purpose mentioned. They should (a) have a large heat of evaporation, a low freezing point, a high vapor density at evaporation-condensation temperature, high heat transfer numbers with bubble vapors and condensation and a low saturated vapor pressure at operational temperature, (b) not be poisonous and inflammable, and (c) be economical compared to forced-water circulation. According to the invention, an azeotropic mixture of water and methyl-propylene glycol fulfills these requirements.

  18. 联合循环用汽轮机的开发研制特点%Development Features of Combined-Cycle Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    蒋浦宁

    2003-01-01

    针对联合循环的特点,简要介绍了如何进行联合循环用汽轮机的开发研制,使之既能满足用户的运行灵活性要求,提高机组效率,又能保证汽轮机产品质量,并降低成本.本文还用实例介绍了机组的设计应用和机型选取.

  19. 基于特征通流面积的汽轮机变工况性能分析%Performance Analysis of Steam Turbine on Off-design Conditions Based on Characteristic Flow Area

    Institute of Scientific and Technical Information of China (English)

    乔海朋; 卢绪祥; 邴汉昆; 王运民

    2011-01-01

    阐述了基于留格尔公式提出的特征通流面积概念的定义及计算方法,在IAPWS - IF97公式基础上,利用Visual Basic 6.0平台初步开发了汽轮机组通流部分特征通流面积计算软件,并以国产600MW超临界机组为研究对象,对机组变工况下级组的特征通流面积进行了计算和分析.研究结果表明:汽轮机级组的特征通流面积在通流部分尺寸不发生变化时,其值保持不变,并且变工况下其计算精度能满足工程要求,可以作为机组通流能力及通流部分故障诊断的准则参数,为机组通流部分的状态监测与故障的精确诊断提供依据.%The definition and calculation method of characteristic flow area (CFA) which based on FlUgel Formula are presented in this paper. On the basis of the IAPWS - IF97 formula, calculation software of CFA for steam turbine flow passage was developed on Visual Basic 6. 0 software platform, and the CFAs of the domestic 600MW supercritical units under off-design conditions were calculated and analyzed. The results show that the calculation accuracy of CFA under off-design conditions is high and fits the project requirements. It is feasible to apply in calculation of variable CFA, monitoring and diagnosis of steam turbine, and to apply in the field of improved design of the flow passage, variable characteristic flow area calculation,monitoring and diagnosis of steam turbine flow passage.

  20. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    Science.gov (United States)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  1. An Analysis on the Air Exciting-vibration Force of Short Vane of Steam Turbine in Non-uniform Airflow Field%非均匀气流场中的汽轮机短叶片间隙气流激振力分析

    Institute of Scientific and Technical Information of China (English)

    张耀明; 柴山; 马浩; 曲庆文; 赵又群; 姚福生

    2001-01-01

    Because the outlet side of fixed blade has a certain thickness, the airflow field of steam turbine is a non-uniform airflow field. Based on the hydrodynamics, the clearance air exciting-vibration force acting on the blades of steam turbine in the non-uniform airflow field is studied by using the momentum theorem in this paper. The velocity of airflow was developed into Fourier series firstly, and then the computational formulas for the short blades in straight stages and twist stages of steam turbine in the non-uniform airflow field was derived. The presented formulas only include the structural parameters and airflow parameters of steam turbine and can overcome the difficulty of selecting efficiency factor in Alford formula, so they can be used to calculate the air exciting-vibration force of steam turbine with non-uniform airflow field easily.%从流体动力学出发,应用动量定理研究了定叶片出气边具有一定厚度的非均匀气流场中汽轮机的间隙气流激振力,将气流速度展开成Fourier级数,并综合考虑了叶片的各项设计参数,并应用理论分析的方法导出了在非均匀气流场中汽轮机直叶片级、扭叶片级短叶片的间隙气流激振力计算公式。

  2. Experimental investigation on combustion of hydrogen-oxygen and methane-oxygen mixtures in the medium of low-superheated steam

    Science.gov (United States)

    Pribaturin, N. A.; Fedorov, V. A.; Alekseev, M. V.; Bogomolov, A. R.; Sorokin, A. L.; Azikhanov, S. S.; Shevyrev, S. A.

    2016-05-01

    Experimental data are represented on the investigation of combustion of hydrogen-oxygen and methane-oxygen mixtures in the medium of low-superheated (initial temperature of approximately 150°C) steam at atmospheric pressure. The influence of the ratio of mass flows of the combustible mixture and steam on the qualitative composition of combustion products and the temperature of produced steam is revealed. Main laws for combustion of the hydrogen-oxygen mixture within the steam flow, which affect the completeness of mixture combustion, are determined. Experimental data on the influence of concentrations of the hydrogen-oxygen mixture within the flow of the steam and the combustible mixture upon the completeness of combustion are given. It is found that, when burning the hydrogen-oxygen mixture within the steam flow with a temperature of 1000-1200°C, it is possible using a variation of the combustible mixture flow. At the same time, the volume fraction of noncondensable gases in the produced steam is no more than 2%. It is revealed that there are several combustion modes of the hydrogen-oxygen mixture within the steam flow, in which, in one case, the steam always suppresses combustion and, in another one, detonation of the combustible mixture combustible mixture occurs. It is found that with the excess air factor close to unit, the combustion of the methane-oxygen mixture within steam and the vapor conversion of methane, which result in the appearance of free hydrogen in the produced high-temperature steam, are possible. The description and the principle of the operation of the experimental bench for investigation of combustion of methane-oxygen and hydrogen-oxygen mixtures in the medium of steam are given. Results of experimental investigations of burning fuel and oxygen in the medium of steam are used in the development of a steam superheater for a hightemperature steam turbine.

  3. LETTER TO THE EDITOR: Homogeneous nucleation for superheated crystal

    Science.gov (United States)

    Iwamatsu, Masao

    1999-01-01

    Homogeneous nucleation of liquid droplets in superheated crystals is considered in order to estimate the maximum superheating of crystals. Using the previously derived universal order parameter model of the crystal-melt transition (Iwamatsu M and Horii K 1996 J. Phys. Soc. Japan 65 2311), it is determined that the catastrophic homogeneous nucleation occurs at 0953-8984/11/1/001/img1, where 0953-8984/11/1/001/img2 is the equilibrium melting point. This numerical estimation is consistent with the results of maximum-superheating experiments.

  4. Superheating of ice crystals in antifreeze protein solutions

    OpenAIRE

    Celik, Yeliz; Graham, Laurie A.; Mok, Yee-Foong; Bar, Maya; Davies, Peter L.; Braslavsky, Ido

    2010-01-01

    It has been argued that for antifreeze proteins (AFPs) to stop ice crystal growth, they must irreversibly bind to the ice surface. Surface-adsorbed AFPs should also prevent ice from melting, but to date this has been demonstrated only in a qualitative manner. Here we present the first quantitative measurements of superheating of ice in AFP solutions. Superheated ice crystals were stable for hours above their equilibrium melting point, and the maximum superheating obtained was 0.44 °C. When me...

  5. Chasing megawatts in combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

    Koch, J. [Power Plant Performance Specialist, Lansdowne, PA (United States); DeGeeter, S. [Ocean State Power, Harrisville, RI (United States); Haynes, C.J. [New England Power Co., Somerset, MA (United States)

    1996-05-01

    Combined cycle owners do not have to accept that combined cycle performance must degrade over time. Through low cost testing using existing instrumentation, a method is presented to identify causes for lost generation. A 500 MW combined cycle plant, with two STAG 207EA units, had lost 17 MW since initial operation, and found that: Gas side fouling on A four HRSG`s accounted for 8 MW of the total loss LP steam turbine efficiency was below design on one unit, contributing 3 MW Condenser air removal was poor on both units, a loss of an additional 2 MW Compressor and turbine section efficiency losses on 2 of 4 GT`s cost over 4 MW The test also revealed that the other two GT`s, both cooling towers, and one of the two steam turbines, were performing at or near design. Thus far 3 MW has been recovered, with planning underway for recovery of another 3 MW. The remaining 11 MW, though not immediately recoverable, will be the focus of planning for the next major outage. This simple method can be used at any combined cycle using existing instrumentation, with minimal intrusion on daily operations. The use of redundant measurements and uncertainty analysis assures valid and useful results.

  6. Advances in superheated drop (bubble) detector techniques

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Alberts, W.G.; Matzke, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    1997-09-01

    State-of-the-art neutron dosemeters based on superheated drop (bubble) detectors are described. These are either active systems for area monitoring, which rely on the acoustical recording of drop vaporisations, or passive pen size ones for personal dosimetry, based on optical bubble counting. The technological solutions developed for the construction of robust devices for health physics applications are described with special emphasis on methods adopted to reduce mechanical shock and temperature sensitivity of the detectors. Finally, a review is given of some current research activities. In particular, a new approach to neutron spectrometry is presented which relies on the thermal effects for the definition of the response matrix of the system. (author).

  7. Valve Assembly Technology of 660 MW Ultra-supercritical Double-reheat Steam Turbine%660 MW超超临界二次再热汽轮机阀门装配技术

    Institute of Scientific and Technical Information of China (English)

    张桂明; 胡开吉

    2016-01-01

    文章就公司自主开发的660 MW二次再热机组的阀门装配技术进行介绍。针对阀门的结构特点,详细介绍了其装配工艺流程、阀芯及阀盖部件的安装,文章内容将为同类型阀门的安装提供有益的借鉴。%This paper introduced the valve assembly technology of 660 MW ultra-supercritical double-reheat steam turbine indepen⁃dent researched and developed by Dongfang Turbine Co.,Ltd.(abbreviate DTC). For the valve design feature, the valve assembly pro⁃cess,valve core and valve seat installation were detailedly introduced. The paper can provide helpful reference for homotype valve as⁃sembly.

  8. Experimental Equipment and Basic Technological Methods of Obtaining Cavitation Protective Coatings on Working Surfaces of Steam Turbine Blades Made of Titanium Alloy VT6 in Order to Replace Imports of Similar Products

    Directory of Open Access Journals (Sweden)

    Bilous, V.A.

    2016-07-01

    Full Text Available The experimental equipment and basic technological methods of obtaining сavitation protective coatings on the working surfaces of blades of steam turbines from titanium alloy VT6 have been created. The selection and the basis of the composition and conditions of synthesis of optimal coating for hardening blades have been justified. The parameters of deposition process of coatings on the blade model have been worked, the experimental technological deposition process of hardening coatings has been created. The tests of titanium alloy VT6 samples with the preferred coatings in simulation conditions close to operational have been conducted. The coatings on the blade model of length up to 130 cm and weight up to 30 kg have been deposited. The velocity of the TiN coating depositing was 10 mkm/h.

  9. 某电厂汽轮机低压缸隔板断裂失效原因分析%Failure Analysis for Diaphragm Fracture of LP Cylinder of Steam Turbine in a Power Plant

    Institute of Scientific and Technical Information of China (English)

    刘金状

    2014-01-01

    The fracture of a gray cast-iron diaphragm in LP cylinder of steam turbine in a power plant was analyzed by means of metallographic test, hardness test and structure analysis. The results suggest that it is normal for microstructure or hardness. Fracture is mainly caused by the stress concentration due to unreasonable structural design. Meanwhile, the proposal for repair welding of gray cast iron diaphragm is put forward.%对某火力发电厂断裂的汽轮机组铸铁隔板进行了金相组织观察、硬度测试和机械结构分析。结果表明隔板的断裂主要是结构设计不合理引起的应力集中造成的。同时,对该铸件的焊接修复提出了合理化建议。

  10. Creep Damage Evaluation of Steam Turbine Rotor Steel by Using the Nonlinear Ultrasonic Technique%汽轮机转子钢蠕变损伤的非线性超声评价

    Institute of Scientific and Technical Information of China (English)

    张萌; 轩福贞

    2016-01-01

    Creep damage is generally produced in the high temperature components of ultra-supercritical steam turbine which will detriment the structural integrity during the long term operation. Therefore, quick and effective identification of the creep damage is very critical for the service safety of steam turbine unit. In the present work, interrupted creep tests of FB2 steel which is commonly used in the ultra-supercritical steam turbine rotor have been conducted. Creep damaged specimens with various damage levels are thus generated. Using the damaged specimens, nonlinear longitudinal ultrasonic evaluation test has been performed and the nonlinear ultrasonic parameters of damaged specimens are obtained. Results indicate that nonlinear ultrasonic parameters increase with the increase of creep damage levels of steam turbine rotor steel. The microstructure of damaged specimens has been analyzed by using the transmission electron microscopy(TEM). Result reveals that the increase of nonlinear ultrasonic parameter can be ascribed to the increase of dislocation density. Furthermore, the increment of nonlinear ultrasonic parameter is related to the dislocation climbing at higher stress and to the dislocation slipping at lower stress. In terms of the dislocation theory, a correlation between the nonlinear ultrasonic parameters2A2A1 and the steady state creep strain rate has been developed accordingly.%超超临界汽轮机高温部件长期服役会产生蠕变损伤,威胁设备的强度安全,快速、有效地检出高温构件蠕变损伤状况对保证设备服役安全意义重大。采用中断蠕变试验,在实验室模拟获得了汽轮机转子钢 FB2不同程度的蠕变损伤,进行损伤后试样的非线性超声纵波表征试验。结果表明:非线性超声参量随转子钢 FB2蠕变损伤程度的增加而增大;透射电镜微观分析表明,超声非线性参量增大与位错密度增加有关;非线性超声纵波参量与高应力水平

  11. Comparative analysis of the economy quality and increasing energy efficiency means for 310MW Steam Turbine%310MW汽轮机组经济节能性对比分析及提高途径

    Institute of Scientific and Technical Information of China (English)

    王昊

    2013-01-01

    Through the maintenance of steam turbine unit, the article contrastively analyses the economy quality be-fore and after repairing 310MW unit and studies the difference between design value and experimental value and puts for-word corresponding improvement measures and discusses the way of economic increase.%  文章通过对汽轮机组的检修,对比分析了检修310MW机组前后的经济性,并研究了设计值与试验值的差别,提出相应的改进措施,探讨了经济性提高的途径。

  12. Effect of the blades and seals system wear on steam turbine efficiency and power; Efecto del desgaste del sistema de alabes y sellos sobre la eficiencia y potencia de las turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso; Kubiak Szyszka, Janusz [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The implementation of a method for steam turbine evaluation through the measured geometry in the flow channel and its operating conditions, is presented. This method, previously developed, allows the identification and quantification of the power and efficiency loss due to the wear of its elements (worn or bent blades, worn seals, deposits, etc.); the benefit that is obtained is a more precise knowledge on the turbine behavior and a basis is acquired to give priority to the maintenance work, from the stand point of energy utilization. In this paper, the power and efficiency loss of a 300 MW steam turbine is located and evaluated, a sensibility analysis is presented for the typical elements that cause the deterioration of the efficiency in this type of turbines. [Espanol] Se presenta la implementacion de un metodo de evaluacion de turbinas de vapor a partir de la geometria medida del canal de flujo y sus condiciones de operacion. Este metodo, previamente desarrollado, permite identificar y cuantificar las perdidas de potencia y eficiencia debido al desgaste de sus elementos (alabes desgastados o doblados, sellos desgastados, depositos, etcetera); el beneficio que se obtiene es un conocimiento mas preciso del comportamiento de la turbina y que se tiene una base para dar prioridad a los trabajos de mantenimiento desde el punto de vista de aprovechamiento de la energia. En este articulo se localizan y evaluan las perdidas de potencia y eficiencia de una turbina de vapor de 300 MW, ademas, se presenta un analisis de sensibilidad para los elementos tipicos que originan el deterioro de la eficiencia en este tipo de turbinas.

  13. Analysis of the Seal Characteristic for LP Cylinder of Large Steam Turbine%三维数字模拟技术在汽轮机低压汽缸汽密性设计中的应用

    Institute of Scientific and Technical Information of China (English)

    陈伯树; 魏军; 杜连庆; 何成君; 平路光

    2011-01-01

    随着大容量、高参数火电机组的不断发展,机组整体汽密性的设计对机组安全性和效率的影响变得越来越重要.将全三维非线性热固、流固耦合数值模拟技术引入到大型汽轮机机组低压汽缸及其部件的汽密性设计分析中,通过对结构的全新改进和优化解决了华能沁北电厂和大唐乌沙山电厂低压汽缸漏汽问题,提高了机组效率.%With the development of the emergence large-capacity, high-parameter thermal power unit, the higher economy and reliability is demanded. The widespread steam seal issue on thermal power unit seriously affects the safe operation and coal-fired efficiency of the steam turbine,and the steam leakage of the low pressure cylinder is more serious and frequent.The seal characteristic of the steam turbine cylinder ( blade ring,etc) was simulated using large-scale finite element software and CFD software in this paper. Through the improvement and optimization in the structure , huaneng qinbei power plant and datang wusha hill power plant LP cylinder steam leakage problems have been resolved , in addition it improve the efficiency of the unit. of the new solution.

  14. 汽轮机凝汽器空气漏入率在线检测方法%On-Line Measurement of Air Leakage Rate of Steam Turbine Condenser

    Institute of Scientific and Technical Information of China (English)

    郭盈; 姚飞; 王学同; 周广顺

    2012-01-01

    A novel technique has been successfully developed to measure, on-line, the air leakage rate of the steam turbine condenser,installed in coal-fire power plant.The measuring principle was described and the calculation formula was derived. The prototyped set-up was constructed to experimentally simulate the air leakage rate of the vacuum pipe of the steam turbine condenser.The discrepancy between the calculated results, based on the newly-developed method, and the experimentally simulated results was found to be less than 1 % . The feasibility of the calculation scheme in developing an integrated device for on-line measurement of the air leakage rate in turbine vacuum system was also tentatively discussed.%提出了一种新的汽轮机凝汽器空气漏入率在线测量方法,阐述了测量原理并推导出了计算公式.在此基础上,搭建了模拟电厂凝汽器抽真空管道环境的实验台并对整个实验系统进行了不确定度分析,通过实验设定值与采用本文提出方法的计算结果比较,相对偏差均在1%以内,从而验证了本文提出方法的正确性.本文工作为下一步研制集成化的汽轮发电机组真空系统漏气率在线测量装置奠定了基础.

  15. The Application of Steam Turbine Steam Path Audit Technology%汽轮机通流状态经济性评估技术的现场应用

    Institute of Scientific and Technical Information of China (English)

    杨海生; 吴瑞涛; 李忠杰

    2012-01-01

    Analysis was made on the factors influencing the turbine steam path efficiency, and the concept of the turbine steam path audit was introduced. Using the turbine steam path technology, quantitative analysis and calculation for the factors influencing the steam turbine efficiency can be made using relevant tool software,which can help the decision making of the key maintenance area during the turbine overhaul. An example was given for one super-critical steam turbine, including the measurement data got during the turbine overhaul and the audit results,and the key maintenance tasks set out based on the steam path audit.%对影响汽轮机通流效率的各项因素的作用机理进行了定性分析,并对汽轮机通流状态经济性评估的基本概念进行了阐述.进行汽轮机通流部分经济性状态评估后,可以利用相关的分析工具软件对影响汽轮机通流部分经济性的因素进行有效分析及计算,为电厂大修中汽轮机的检修提供检修的重点.以某一超临界660MW汽轮机为例,给出了汽轮机通流状态经济性评估的大修通流状态实测数据及评估结果,在此基础上确定了汽轮机大修的重点检修工作.

  16. Effects of shot peening on short crack growth rate and resulting low cycle fatigue behaviour in low pressure turbine blade material

    OpenAIRE

    He, B.; Soady, K.A.; Mellor, B.G.; Morris, A; Reed, P.A.S

    2013-01-01

    The effect of shot peening on subsequent low cycle fatigue behaviour of a representative low pressure steam turbine blade material has been investigated in bend test samples. An analysis of the short fatigue crack growth behaviour has been conducted. For samples with no stress concentration feature, shot peening was found to have a more evident beneficial effect at lower strain levels than at higher strain levels, whereas for samples with a stress concentration feature, the beneficial effect ...

  17. Superheating in linear polymers studied by ultrafast nanocalorimetry.

    Science.gov (United States)

    Minakov, A A; Wurm, A; Schick, C

    2007-05-01

    To study phase transition kinetics on submillisecond time scale a sensitive ultrafast nanocalorimeter was constructed. Controlled ultrafast cooling, as well as heating, up to 10(6) K/s was attained. The method was applied for the measurements of the superheating phenomenon in a set of linear polymers: iPS, PBT, PET, and iPP. A power law relation between the superheating and the heating rate holds in the heating rate range 10(-2) - 10(4) K/s. A limiting superheating of about 10% of the melting temperature was observed at rates above 10(4) - 10(5) K/s. This limit depends on annealing conditions before sample melting. The observed superheating limit, as well as the power law, can be accounted for the internal stresses near the crystalline amorphous interface in semicrystalline polymers induced by heating, which are related to the thermal expansion gradients inherent in a semicrystalline material.

  18. WIMP searches with superheated droplet detectors Status and Prospects

    CERN Document Server

    Collar, J I; Limagne, D; Miley, H S; Morlat, T; Puibasset, J; Waysand, G

    2001-01-01

    SIMPLE (Superheated Instrument for Massive ParticLE searches) employs superheated droplet detectors (SDDs) to search for Weakly Interacting Massive Particle (WIMP) dark matter. As a result of the intrinsic SDD insensitivity to minimum ionizing particles and high fluorine content of target liquids, competitive WIMP limits were already obtained at the early prototype stage. We comment here on the expected immediate increase in sensitivity of the program and on future plans to exploit this promising technnique.

  19. Heat treatment of scallop adductor muscle using superheated steam.

    Science.gov (United States)

    Abe, T; Miyashita, K

    2007-08-01

    Scallop (Patinopecten yessoensis) adductor muscles were heated using superheated steam (150 and 200 degrees C), boiling (98 degrees C), and normal steaming (95 degrees C). The amounts of amino acids, water-soluble peptides, and nucleotides, expressed as extractive nitrogen in scallop products, are very important elements of quality and taste. After 15-min heating of scallop muscles with normal steaming and boiling, respective losses of 50% and 64% of the extractive nitrogen were observed. However, most extractive nitrogen (> 86%) remained in the scallop muscles treated with superheated steam at 150 and 200 degrees C. Protective effects of superheated steam against elution loss of nitrogen compounds were also observed in amino acid analyses of the heated products. The scallop-muscle surface temperature during treatment with superheated steam increased more quickly than that with normal steaming and boiling. The rapid water loss and the surface protein denaturation engendered formation of a 30-mum-thick film covering the surface, which prevented extractive nitrogen loss from internal tissues. Superheated steam treatment at 200 degrees C caused browning, surface shrinkage, and 47% weight loss. In marked contrast, the appearance and the weight loss of sample treated at 150 degrees C were almost the same as those of normal steaming and boiling-treated samples. These results suggested that superheated steaming at 150 degrees C is an optimal heat treatment of scallop adductor muscles.

  20. Results of studies on application of CCMHD to advanced fossil fuel power plant cycles

    Energy Technology Data Exchange (ETDEWEB)

    Foote, J.P.; Wu, Y.C.L.S.; Lineberry, J.T.

    1998-07-01

    A study was conducted to assess the potential for application of a Closed Cycle MHD disk generator (CCMHD) in advanced fossil fuel power generation systems. Cycle analyses were conducted for a variety of candidate power cycles, including simple cycle CCMHD (MHD); a cycle combining CCMHD and gas turbines (MHD/GT); and a triple combined cycle including CCMHD, gas turbines, and steam turbines (MHD/GT/ST). The above cycles were previously considered in cycle studies reported by Japanese researchers. Also considered was a CCMHD cycle incorporating thermochemical heat recovery through reforming of the fuel stream (MHD/REF), which is the first consideration of this approach. A gas turbine/steam turbine combined cycle (GT/ST) was also analyzed for baseline comparison. The only fuel considered in the study was CH4. Component heat and pressure losses were neglected, and the potential for NOx emission due to high combustion temperatures was not considered. Likewise, engineering limitations for cycle components, particularly the high temperature argon heater, were not considered. This approach was adopted to simplify the analysis for preliminary screening of candidate cycles. Cycle calculations were performed using in-house code. Ideal gas thermodynamic properties were calculated using the NASA SP- 273 data base, and thermodynamic properties for steam were calculated using the computerized ASME Steam Tables. High temperature equilibrium compositions for combustion gas were calculated using tabulated values of the equilibrium constants for the important reactions.

  1. Thermodynamic Analysis of Combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    A.K.Tiwari,

    2010-04-01

    Full Text Available Air Bottoming Cycle (ABC can replace the heat recovery steam generator and the steam turbine of the conventionalcombined cycle plant. The exhaust energy of the topping gas turbine of existing combine cycle is sent to gas-air heat exchange, which heats the air in the secondary gas turbine cycle. In 1980’s the ABC was proposed as an alternative for the conventional steam bottoming cycle. In spite of the cost of reducing hardware installations it could achieve a thermal efficiency of 80%. The complete thermodynamic analysis of the system has been performed by using specially designed programme, enabling the variation of main independent variables. The result shows the gain in net work output as well as efficiency of combined cycle is 35% to 68%.

  2. Discrimination of events in superheated liquid

    Science.gov (United States)

    Archambault, Simon

    2010-02-01

    PICASSO is a Dark Matter search experiment using superheated droplets of C4F10 as the active detector material, suspended in an elastic polymer. If a WIMP (Weakly Interacting Massive Particle) hits a nucleus inside a droplet, the recoiling nucleus will deposit its energy in a heat spike, triggering a phase transition. The setup, installed at SNOLab, 2 km underground, consists of 32 cylindrical detectors of 4.5L. The acoustic signals emitted during a phase transition are recorded by nine piezo-electric transducers mounted on the detector walls and the waveforms are analysed offline. In this way, different types of events can be identified using different variables. One of these variables, which is proportional to the total energy of the acoustic signal, allows discrimination among neutron or WIMP-induced events, background alpha particle induced events and electronic noise; another discrimination variable is constructed from the Fast Fourier Transform of the signal and allows the discrimination of other classes of backgrounds. )

  3. Técnica de monitorado continuo (on – line para la evaluación del estado técnico de los turbogrupos de 64 y 100 MW. // Technique of continuous monitored (on - line for the evaluation of the technical state in steam turbine units of 64 and 100 MW.

    Directory of Open Access Journals (Sweden)

    F. de la Torre. Silva

    2001-04-01

    Full Text Available En este trabajo se presenta el resultado del estudio de factibilidad realizado a los turbogrupos de 64 y 100 MW de dosCentrales Termoeléctricas, sobre el empleo de técnicas de monitorado continuo “on line” para la evaluación del estadotécnico de estos turbogrupos.Palabras claves: Turbinas de vapor,vibraciones, monitorado continuo “on line”, diagnóstico.______________________________________________________________________Abstract:In this work an study of feasibility is presented. This study is carried out in steam turbine units of 64 and 100 MW, and show the use ofcontinuous monitored technique (on line for the evaluation of the technical state of these turbine units.Key Words: Steam turbines, vibrations, continuous monitoring on line, turbines supervision, Diagnosis,technical state evaluation.

  4. Superheating of ice crystals in antifreeze protein solutions

    Science.gov (United States)

    Celik, Yeliz; Graham, Laurie A.; Mok, Yee-Foong; Bar, Maya; Davies, Peter L.; Braslavsky, Ido

    2010-01-01

    It has been argued that for antifreeze proteins (AFPs) to stop ice crystal growth, they must irreversibly bind to the ice surface. Surface-adsorbed AFPs should also prevent ice from melting, but to date this has been demonstrated only in a qualitative manner. Here we present the first quantitative measurements of superheating of ice in AFP solutions. Superheated ice crystals were stable for hours above their equilibrium melting point, and the maximum superheating obtained was 0.44 °C. When melting commenced in this superheated regime, rapid melting of the crystals from a point on the surface was observed. This increase in melting temperature was more appreciable for hyperactive AFPs compared to the AFPs with moderate antifreeze activity. For each of the AFP solutions that exhibited superheating, the enhancement of the melting temperature was far smaller than the depression of the freezing temperature. The present findings clearly show that AFPs adsorb to ice surfaces as part of their mechanism of action, and this absorption leads to protection of ice against melting as well as freezing. PMID:20215465

  5. Superheating of ice crystals in antifreeze protein solutions.

    Science.gov (United States)

    Celik, Yeliz; Graham, Laurie A; Mok, Yee-Foong; Bar, Maya; Davies, Peter L; Braslavsky, Ido

    2010-03-23

    It has been argued that for antifreeze proteins (AFPs) to stop ice crystal growth, they must irreversibly bind to the ice surface. Surface-adsorbed AFPs should also prevent ice from melting, but to date this has been demonstrated only in a qualitative manner. Here we present the first quantitative measurements of superheating of ice in AFP solutions. Superheated ice crystals were stable for hours above their equilibrium melting point, and the maximum superheating obtained was 0.44 degrees C. When melting commenced in this superheated regime, rapid melting of the crystals from a point on the surface was observed. This increase in melting temperature was more appreciable for hyperactive AFPs compared to the AFPs with moderate antifreeze activity. For each of the AFP solutions that exhibited superheating, the enhancement of the melting temperature was far smaller than the depression of the freezing temperature. The present findings clearly show that AFPs adsorb to ice surfaces as part of their mechanism of action, and this absorption leads to protection of ice against melting as well as freezing.

  6. Analysis on High Temperature Strength and Sealing Behavior of U-type Seal in Steam Turbine Valves%汽轮机进汽阀U型密封高温强度与密封性能分析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      U型密封因其优越的密封性能而被广泛应用在超超临界汽轮机进汽阀门中。随着运行参数(温度,压力)不断提升, U 型密封承受的蠕变越发严重。为了研究 U 型密封在高参数运行条件下的蠕变强度与密封性能,引用经过时间硬化修正的 Norton-Bailay 蠕变本构方程和基于孔洞长大理论的多轴蠕变模型,分析计算了汽轮机进气阀U型密封2×105 h工作时域内接触面位置、接触应力和蠕变多轴度因子的变化规律。结果表明:随蠕变时间增加,U型密封的接触应力下降明显;U型密封的关键部位受到较大多轴应力影响,并产生较大的 Cocks-Ashby 蠕变等效应变,试验结果与预测结果一致。%U-type seal has been widely used in the inlet valves of ultra-supercritical steam turbines due to its superior sealing performance. However, the U-type seal bears greater creep deformation with the increase of the operational parameters (T, P). In order to investigate the creep strength and sealing performance of the U-type seal, the modified time-hardening Norton-Bailay constitutive equation and multiaxial cavity growth model were employed in the calculation. Furthermore, the variation of contact position, contact stress and multiaxial factor of U-type seal of steam turbine valve were analyzed under 0.2 million creep hours. The results illustrate that the contact stress of U-type seal significantly reduces with the creep hours increases. Some key areas of U-type seal suffer great multi-axial state of stress, and then huge Cock-Ashby equivalent strain is produced. The experimental result is consistent with predicted result.

  7. 汽轮发电机组轴系扭振多指标非线性协调控制%Multi-index nonlinear coordination control design for steam-turbine generator shafting torsional vibration

    Institute of Scientific and Technical Information of China (English)

    李啸骢; 鹿建成; 韦善革; 梁志坚; 徐俊华

    2014-01-01

    为减少机电扰动对汽轮发电机组轴系扭振的影响,在单机无穷大系统中,建立了汽轮发电机组轴系、励磁和调速的六阶非线性状态空间数学模型。基于反馈精确线性化理论,设计了发电机组励磁和调速的多指标非线性协调控制(MINC)策略。同时与线性最优控制(LOC)方法做对比,仿真表明:采用MINC方法,当系统受到短路故障,调功和调压扰动时,不仅能更好地抑制汽轮机和发电机之间功角位移偏差的振荡,减少轴系扭振事故的发生,还可以兼顾各状态量的动、静态性能,提高电力系统稳定运行水平。%To reduce the effect of mechanical and electrical disturbance on torsional vibration of steam-turbine generator shafting, in a single machine infinite system, a six order nonlinear state space model is set up for steam turbine generator shafting based on the generator excitation and speed-regulation system. According to the accurate feedback linearization theory, the multi-index nonlinear coordination (MINC) control strategy is designed for suppressing the torsional vibration of shafting. The strategy is compared with linear optimal control (LOC) method. The simulation results show that when the short-circuit fault occurs and the regulating power and voltage are disturbed, the MINC method can restrain oscillation of the angular displacement deviation between turbine and generator, reduce the risk of shaft torsional vibration, give better consideration of both dynamic and static performance of each state quantity, and stabilize the operation of power system.

  8. Numerical calculation of superheating magnetic fields and currents for superconducting slabs

    Science.gov (United States)

    Landau, I. L.; Rinderer, L.

    1995-08-01

    Numerical calculations of superheating magnetic fields and superheating currents for superconducting slabs for a wide range of the sample thickness are presented. The calculations were made for low values of Ginzburg-Landau parameter κ, i.e., for type-1 superconductors. We propose also experimental procedures to measure superheating fields and currents in films and bulk samples.

  9. Acoustic response of superheated droplet detectors to neutrons

    Science.gov (United States)

    Gao, Size; Zhang, Guiying; Ni, Bangfa; Zhao, Changjun; Zhang, Huanqiao; Guan, Yongjing; Chen, Zhe; Xiao, Caijin; Liu, Chao; Liu, Cunxiong

    2012-03-01

    The search for dark matter (DM) is a hot field nowadays, a number of innovative techniques have emerged. The superheated droplet technique is relatively mature; however, it is recently revitalized in a number of frontier fields including the search for DM. In this work, the acoustic response of Superheated Droplet Detectors (SDDs) to neutrons was studied by using a 252Cf neutron source, SDDs developed by the China Institute of Atomic Energy, a sound sensor, a sound card and a PC. Sound signals were filtered. The characteristics of FFT spectra, power spectra and time constants were used to determine the authenticity of the bubbles analyzed.

  10. 年产百万吨乙烯装置裂解气压缩机用汽轮机的研制%Development of steam turbine for cracking gas compressor with annual output of one million tons of ethylene device

    Institute of Scientific and Technical Information of China (English)

    方寅; 孙烈; 张科; 刘龙海

    2012-01-01

    Aiming at the localization of steam turbine for cracking gas compressor with annual output of one million tons of ethylene device, it was introduced that the background and process of the project based on the instance of the application of steam turbine research and development projects in Tianjin Petrochemical. Combined with conforming and implementation of the development scheme which relies on the first domestic set of steam turbine used in this condition, it was described in detail the main technical parameters,structure configuration, technical characteristics and the international standard needed to be complied with, as well as the key issues, research difficulties and the measures. In the end, the three innovation patents were introduced which were achieved during the process of the steam turbine's development of localization. The results indicate that the localization of the steam turbine is completely realized.%针对年产百万吨乙烯装置裂解气压缩机用汽轮机的国产化问题,依托天津石化实例应用汽轮机的研制开发项目,介绍了年产百万吨乙烯装置用汽轮压缩机组国产化研制论证立项的背景和过程,结合国内首台套该用途汽轮机研制方案的确定和实施,详述了该用途汽轮机的主要技术参数、结构配置、技术特点、需遵循和执行的国际标准,以及研制过程中需要解决的关键问题、方案难点和采取的对策措施,最后简述了该汽轮机国产化研制中获得的3个创新专利成果.研究结果表明,本研究实现了该用途汽轮机的完全国产化.

  11. Brush Seal in the Application of Energy Saving in a Steam Turbine%刷式汽封在汽轮机节能减排中的应用

    Institute of Scientific and Technical Information of China (English)

    丁杨; 何国亮; 谷新房

    2012-01-01

    介绍刷式汽封工作原理、结构特点,结合电厂的实际使用情况,根据机组A级检修前后的热力试验,分析刷式汽封在发电厂汽轮机节能减排中应用,在保障机组安全运行的条件下,通过提高轴端汽封、隔板汽封的径向密封问隙水平,实现节能减排。%This paper introduced the introductions of brush seal about works and structural features, combined with the actual use of the power plant, according to the unit A -level maintenance before and after the thermal test, the brush seal in the application of energy saving in the power plant steam turbine practical is analyzed. Under the conditions of safe operation, it can achieve the purpose of energy saving by improving the shaft gas seal, radial seal gland partition gap level.

  12. 大型汽轮机低压排汽缸气动分析研究%Aerodynamic Performance AnaIysis of LP Exhaust Hood for Large Power Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    江生科; 彭英杰

    2014-01-01

    Aerodynamic performance of the LP exhaust hood influenced power and efficiency of the steam turbine. Numerical anal-ysis for single cylinder and LP last stage coupling with exhaust hood showed that the exit flow field's inhomogeneity and pre-swirl of last stage blade affected the aerodynamic performance of LP exhaust hood. Design of LP exhaust hood with high performance should consider the interaction of the last stage and flow field of LP exhaust hood.%低压排汽缸的气动性能影响汽轮机组的功率和效率。文章对单独排汽缸和汽轮机低压末级整圈与排汽缸耦合进行了数值分析对比,发现汽轮机末级动叶出口流场的不均匀性和强烈的预旋影响低压排汽缸的气动性能。高性能的低压排汽缸设计应该考虑末级与低压排汽缸流场之间的相互作用。

  13. Quantitative Calculation of the Influence of Cold End Parameters on the Steam Turbine Exhaust Temperature%冷端参数变化对汽轮机排汽温度影响的定量计算

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Based on heat transfer theory and formula for heat transfer coefficient of condenser provided by American heat exchange institute(HEI) and mathematical derivation,and reasonably simplify according to the Taylor’ s formula,get the function of changes of steam turbine cold end parameters on exhaust steam temperature, the paper analyzed the function relationship of the error and points out the application conditions.The function obtained can be used for the analysis of the necessity of cold end adjustment and transformation, and has the guiding significance for the energy saving of the cold end of the turbine.%根据传热学原理和美国传热协会( HEI)提供的凝汽器换热系数公式进行数学推导,并根据泰勒公式进行合理简化,得到汽轮机冷端各参数的变化对排汽温度影响的函数关系式,分析了函数关系式的误差并指出了应用条件。得到的函数可以用于对冷端调整和改造必要性的分析,对汽轮机冷端节能具有指导意义。

  14. 试论火力发电厂汽机辅机现状及优化策略%On the Current Situation and Optimization Strategies of Thermal Power Plant Steam Turbine Auxiliary

    Institute of Scientific and Technical Information of China (English)

    辛继群; 梁健

    2013-01-01

    随着我国社会的不断进步,经济的快速发展,对火力发电需求越来越高,汽机辅机是整个火力发电中的一个重要组成部分,它在火力发电中起到了决定性的作用。可随着现在用电量的日渐加大,火力发电厂的发电量也在逐日上涨,这对汽机辅机造成了一定程度的影响。%With the continuous progress of our society and the rapid economic development, the demand for power generation is increasing. Steam turbine auxiliary is an important part in the whole power generation, and it plays a decisive role in thermal power. With the gradually increased electricity consumption, the generating capacity of thermal power is also rising day by day, which has caused a certain influence on the auxiliary turbine.

  15. The Development and Application of Online Life Loss Monitoring System for Steam Turbine Rotors%汽轮机转子寿命损耗在线监测系统开发及应用

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    基于有限差分法,采用MATLAB和组态软件开发了基于火电厂SIS数据平台的汽轮机组寿命在线监测系统,实时考虑放热系数变化,转子材料物性变化等因素。通过现场运行,结果表明该系统能很好的反映出转子温度场及应力场分布,可以为机组的安全、经济运行及寿命管理提供有效的技术手段,能够很好地满足工程实际需要。%Based on the finite difference method,the online life loss monitoring system was developed by using Matlab and Configuration software tools, basing on data center platform of SIS, the real -time heat transfer coefficient and the rotor material properties changes and other factors have been considered.The actual field operations showed that the system can well reflect the distribution of temperature field and stress field.The system can provide effective technical means for the safe, economical operation and life management for the steam turbine,can effectively meet the needs of engineering practical.

  16. 汽轮机转子的热力耦合随机动态响应分析%The Coupled Stochastic Dynamic Response Analysis of the Steam Turbine Rotor

    Institute of Scientific and Technical Information of China (English)

    石磊; 周宗和; 杨自春

    2013-01-01

    Not only consider the steam turbine rotor under multiaxial stress influence,and consider the thermoelastoplastic of the rotor, based on the integral Laguerre stochastic finite element method ( LISFEM) , the random dynamic response characteristics of the turbine rotor are analyzed. Then,using the second development function of ANSYS - UIDL (user interface design language) , the dynamic response analysis of the turbine rotor is modally encapsulated, embedded in ANSYS software, and convenient for the operation.%不仅考虑汽轮机转子承受多轴应力的影响,并且考虑转子材料的热弹塑性,利用基于Laguerre积分的随机有限元方法(LISFEM)对汽轮机转子的随机动态响应特性进行分析.然后,利用ANSYS二次开发功能——UIDL(用户界面设计语言),对汽轮机转子的随机动态响应分析过程进行模块化封装,嵌入ANSYS软件当中,以方便用户操作分析.

  17. Research on Key Technology of Supercritical Steam Turbine%超临界汽轮机研制的关键技术及解决策略研究

    Institute of Scientific and Technical Information of China (English)

    杨其国

    2011-01-01

    针对超临界汽轮机蒸汽参数高的运行特点,指出了汽轮机零部件高温安全问题、固体颗粒腐蚀、汽流激振以及对机组效率的更高要求等关键难点.通过开发高温材料,采用转子冷却、防汽流激振和同体颗粒腐蚀等设计技术.设计制造了超临界汽轮机,圆满地解决了以上难题,在实际运行中安全高效.也为我国自主开发更高等级机组打下坚实基础.%According to the high steam parameter of supercritical steam turbine in running, this paper indicates a series of key difficulties, such as safety of parts in high temperature condition, solid particles erosion , steam excited vibration,more higher efficiency, etc. These difficulties above were solved successfully by technologies of high temperature materials,rotor cooling, protection against steam excited vibration and solid particles erosion. This power unit has high safety and efficiency in working, lays a solid foundation for development of high parameters units by self-research in China.

  18. Research on Nil-Ductility Transition Temperature of Steel Used for Cylinder of Industrial Steam Turbine%工业汽轮机汽缸用材无塑性转变温度的研究

    Institute of Scientific and Technical Information of China (English)

    何成; 刘中华; 周黎明; 刘京伟; 林云; 宋思远

    2016-01-01

    The issue that the temperature of test liquid required by the hydraulic test shall be higher than the nil-ductility transition temperature of test material has been expressed. The NDT temperature of steel used for the cylinder of industrial steam turbine has been examined by the drop test, and the factor influenced on NDT temperature has been analyzed as well. By adopting the advanced smelting technology and heat treatment process to strictly control P and S contents, and refining the grain, NDT temperature of steel could be reduced effectively.%针对水压试验要求试验液体温度应高于试验材料的无塑性转变温度的问题,通过落锤试验测定了工业汽轮机汽缸用材的NDT温度,并分析了影响NDT温度的因素。通过先进的冶炼技术和热加工工艺严格控制P、S含量,细化晶粒等手段,可有效降低钢材的NDT温度。

  19. To Wash Soluble Salt Deposits in the Flow Section of Steam Turbine with Wet Steam%利用湿蒸汽冲洗汽轮机通流部分可溶性盐垢

    Institute of Scientific and Technical Information of China (English)

    王长友; 党占东; 胡海

    2014-01-01

    Through analysis of the causes of high turbine flow resistance and high tem-perature of thrust bearing shoes, it was found that the main cause had been serious scaling in the flow section, which reduced the circulation area and in turn decreased the work ca-pacity of steam turbine preventing the unit from boosting to rated load. The causes of salt deposit in the flow section were also analyzed and studied and a flushing plan was drawn up, to reduce the resistance in the unit flow passages, lower the temperature of the thrust shoes and improve the safety and economy of the generating unit.%通过对汽轮机组通流部分阻力大、推力瓦温度高的原因进行分析,得出其主要原因为通流部分结垢严重,流通面积缩小,导致汽轮机做功能力下降,使机组无法带至额定负荷;并对通流部分结垢的原因进行分析、研究,作出冲洗方案,以求降低机组的通流部分阻力、推力瓦温度,提高机组的安全、经济性。

  20. Superheated starch: A novel approach towards spreadable particle gels

    NARCIS (Netherlands)

    Steeneken, P.A.M.; Woortman, A.J.J.

    2009-01-01

    When aqueous potato starch suspensions were heated into the solution state and cooled, spreadable particle gels were obtained with a spherulite morphology and a cream-like texture. This so-called superheated starch (SHS) exhibits more effective gelling properties than maltodextrin, which is

  1. La moral de los superhéroes

    Directory of Open Access Journals (Sweden)

    Jhon Rozo Mila

    2015-12-01

    Full Text Available Los superhéroes, el deber moral y la obligación; El caso de Spider-Man y los X-Men. Laura Victoria Bolaño Pérez; Universidad del Rosario, colección Ópera Prima, Bogotá, 2012, 309 págs.

  2. 汽轮机低压调节级动叶片水蚀分析%Analysis on Water - Erosion of Moving Blade in Low - pressure Control Stage of a Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    周文远; 朱正写; 王鹏; 纪绣涛

    2012-01-01

    烯烃装置裂解气压缩机组大检修期间发现汽轮机低压调节级动叶片“蜂窝状点蚀”现象比较严重,对应的静叶片及后2级静叶片也有点蚀现象。分析发现利用湿蒸汽对汽轮机吹扫的方法存在缺陷,在主蒸汽降温的过程中只考虑了高压缸防水蚀的影响,忽略了抽汽背压不可控,导致低压缸进汽压力相对该处的进汽温度过高,部分蒸汽产生冷凝液,蒸汽中夹带的水滴撞击在动叶片出汽边背弧上,致使材料疲劳破坏形成水蚀。根据操作经验和理论分析确定:吹扫工况时,低压调节级的进汽压力应低于170℃时的蒸汽饱和压力,抽汽压力应低于0.8MPa,并利用蒸汽管网改造,控制抽汽压力在0.4~1.6MPa。通过优化操作参数完全可以避免低压调节级动叶片水蚀。%Serious "honeycomb pitting corrosions" were found in the moving blades of the steam turbine's low -pressure control stage in the overhaul of the cracked gas compressor train, corresponding stationary blades and after the two - stage stationary blades also had "pitting corrosion". The analysis concluded that there was negligence in the flushing of steam turbine with wet steam. In the process of lowering the steam temperature, only the impact of water erosion of HP cylinder was considered and uncontrollable extracted steam pressure was ignored. These led to excessive higher temperature of inlet steam as compared with the pressure. Condensate was formed from some steam, water droplets entrained in the steam impinged on the back arc of the moving blades, the material was fatigued and water erosion was formed. Based upon the operating experience and theoretical analysis, in flushing operation, the pressure of inlet steam of LP control stage should be lower than steam saturation steam at 170℃, and the pressure of extracted steam should be lower than 0.8 MPa. The pressure of extracted steam was controlled within 0. 4 1

  3. Design of Steam Turbine Blades Based on BP (Back Propagation) Neural Network and Decomposition Techniques%基于BP神经网络和分解技术的汽轮机叶片可靠性反求设计

    Institute of Scientific and Technical Information of China (English)

    段巍; 王璋奇; 万书亭

    2009-01-01

    The reliability reverse-solution-seeking design of steam turbine blades aims at determining the design parameters of blades with unknown probability to meet a given reliability requirement.In the light of the blade function being a random variable implicit function,a reliability reverse-solution-seeking design method was presented based on finite element method,BP neural network and decomposition techniques.It combined the finite element method with BP neural network to establish an approximate analytic expression showing the relationship between the performance function and the random input variables.By employing the decomposition techniques,the overall optimization problem involving the solution-seeking of random design parameters was decomposed into a main problem and sub-problems.By way of the sub-problems,the standard optimization toolbox was used directly to obtain the reliability indexes,and the decomposition and iterative techniques were employed to seek solutions to the main problem,thus obtaining the sensitivity of the random design parameters and target reliability indexes to various random variables.With the equal and straight blades of a steam turbine on a test rig serving as an example,the concrete application process of the method was expounded.The method features a simple mathematical expression and can be directly used in standard optimization programs.It successfully solved the reliability reverse-solution-seeking design problem of blades under an implicit function,thus enjoying a relatively good application value for engineering projects.%汽轮机叶片可靠性反求设计旨在确定叶片未知概率设计参数以满足给定的可靠度要求.针对叶片功能函数为随机变量隐性函数的情况,提出了基于有限元、BP神经网络和分解技术的可靠性反求设计方法,该方法将有限元和BP神经网络相结合以构造功能函数与随机输入变量之间的近似解析表达式,运用分解技术,将求解随机

  4. Generating power at high efficiency combined cycle technology for sustainable energy production

    CERN Document Server

    Jeffs, E

    2008-01-01

    Combined cycle technology is used to generate power at one of the highest levels of efficiency of conventional power plants. It does this through primary generation from a gas turbine coupled with secondary generation from a steam turbine powered by primary exhaust heat. Generating power at high efficiency thoroughly charts the development and implementation of this technology in power plants and looks to the future of the technology, noting the advantages of the most important technical features - including gas turbines, steam generator, combined heat and power and integrated gasification com

  5. 1000 MW超超临界汽轮机高压外缸蠕变强度的分析%Creep Strength Analysis on HP Outer Casing of a 1 000 MW Ultra Supercritical Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    蒋浦宁

    2013-01-01

    以1 000 MW超超临界汽轮机高压外缸为研究对象,通过引入Norton-Bailey材料蠕变本构方程和Cocks-Ashby多轴韧度系数,对汽缸轴对称二维模型的温度场、应力场和CA蠕变等效应变分布进行了计算,找出了结构设计中不合理区域并提出相应的结构改进方案.结果表明:经改进的高压外缸结构设计是合理的;CA蠕变等效应变计算结果均小于推荐考核标准,该1 000 MW超超临界汽轮机高压外缸的高温蠕变应变强度能够满足设计要求.%Taking the high-pressure outer casing of a 1 000 MW ultra supercritical steam turbine as an object of study, and by adopting the Norton-Bailey material creep constitutive equation and Cocks-Ashby multiaxial coefficient, the temperature field, stress field and the CA equivalent creep strain dictribution of the 2D axisymmetric model were calculated, during which the unreasonable structure of original design was found out and impoved with corresponding schemes. Results show that the improved structure of the HP outer casing is reasonable; all the calculated results of CA equivalent creep strain are less than those in the recommended criteria for assessment. The high-temperature creep strain of above mentioned outer casing can meet the design requirements.

  6. Analysis of Steam Turbine Reheat Butterfly Valve Jam Phenomena based on CFX Simulation%基于CFX仿真分析汽轮机再热蝶阀卡阀现象

    Institute of Scientific and Technical Information of China (English)

    张守印; 汤春梅; 张峻峰

    2014-01-01

    汽轮机再热蝶阀是汽轮机组的重要元件,该类型蝶阀在冷起动过程中经常发生卡阀。研究表明,由于零件间热量传递速度存在差异,所以在冷起动过程中,不同零件物理性能差异导致了径向间隙和轴向间隙的变化不同。本文采用 CFX流固耦合有限元法定量分析再热蝶阀在冷起动过程中阀体和阀瓣之间的间隙变化,这对于解决该类工程问题具有重要的理论价值和指导意义。%The reheat butterfly valve is a vital component in the steam turbine unit,mechanical j amming often emerges in such mechanisms during the cold start.Research showed that the different physical property leads to the different trans-mission speed of heat in parts,so the radial and axial clearance varies greatly in the process of cold start.CFX fluid-solid coupling finite element method was used to quantitatively analyze the clearance variation between valve body and valve clack, which has important theoretical value and realistic guiding significance to the solution of such engineering problems.

  7. Cause analysis of axial displacement augmentation for steam feed pump steam turbine%汽动给水泵汽轮机轴向位移增大原因分析

    Institute of Scientific and Technical Information of China (English)

    王占武

    2015-01-01

    Analyzes the problem of axial displacement augmentation for A and B steam feed pump steam turbine of No.2 unit in Ningdong thermal power plant,analyzes the cause factor of failure, puts forward improvement method and preventing measure. the analysis result shows that the main cause of rotor axial displacement augmentation is that low temperature saturation steam of deaerator come into turbine of steam feed pump and result in moving blade of turbine of steam feed pump to bring water induction and induce rotor axial thrust augmentation,further burn-out thrust bearing shoe,abrasion seal gear,axial displacement protection device to act,so caused turbine of steam feed pump to trip.%针对宁东热电厂2号机组A、B汽动给水泵汽轮机轴向位移增大的问题,对事故原因进行分析,提出改进方法及预防措施.分析结果表明:转子轴向位移增大的主要原因是除氧器低温饱和蒸汽进入汽动给水泵汽轮机,造成了汽动给水泵汽轮机动叶受到水冲击,转子轴向推力增大,进而使得推力瓦块烧损,汽封齿磨损,轴向位移保护动作,引发给水泵汽轮机跳闸.

  8. 循环水泵前池水位降低对汽轮机冷端系统运行性能影响分析%Influence Analysis of Circulating Water Pump Forebay Water Lowering on the Operating Performance of Steam Turbine Cold-end System

    Institute of Scientific and Technical Information of China (English)

    田思来; 程东涛; 居文平

    2016-01-01

    Water lowering of the power station circulating water pump forebay compared to local water level influences the safety and economy of the steam turbine cold-end system.Through quantitative analysis and qualitative analysis ,the analysis of impact of water lowering of the circulating water pump forebay on the economic performance of the steam turbine cold -end system,clearly put forward decision criteria for operating safety of the steam turbine cold-end system.A set of simple and practical calculation method is developed , applied to the quantitative analysis on the problems existing in the circulating water system,at the same time provides guidance advice for the work of design and selection of circulating water system of same type.%电站循环水泵前池水位相对水源地水位下降,对汽轮机冷端系统安全性和经济性运行产生重要影响。通过定量分析和定性分析相结合,分析计算循环水泵前池水位下降对汽轮机冷端系统运行经济性的影响量,明确了对汽轮机冷端系统运行安全性影响的判定标准。形成了一套简便、实用的分析计算方法,对循环水取水系统存在的问题进行量化分析,同时为同类型循环水取水系统的设计选型工作提供了指导建议。

  9. Numerical simulation of superheated vapor bubble rising in stagnant liquid

    Science.gov (United States)

    Samkhaniani, N.; Ansari, M. R.

    2017-09-01

    In present study, the rising of superheated vapor bubble in saturated liquid is simulated using volume of fluid method in OpenFOAM cfd package. The surface tension between vapor-liquid phases is considered using continuous surface force method. In order to reduce spurious current near interface, Lafaurie smoothing filter is applied to improve curvature calculation. Phase change is considered using Tanasawa mass transfer model. The variation of saturation temperature in vapor bubble with local pressure is considered with simplified Clausius-Clapeyron relation. The couple velocity-pressure equation is solved using PISO algorithm. The numerical model is validated with: (1) isothermal bubble rising and (2) one-dimensional horizontal film condensation. Then, the shape and life time history of single superheated vapor bubble are investigated. The present numerical study shows vapor bubble in saturated liquid undergoes boiling and condensation. It indicates bubble life time is nearly linear proportional with bubble size and superheat temperature.

  10. Superheated water chromatography--a green technology for the future.

    Science.gov (United States)

    Smith, Roger M

    2008-03-14

    Reversed phase liquid chromatography using superheated water as the mobile phase, at temperatures between 100 and 250 degrees C, offers a number of advantages for the analyst. It is an environmentally clean solvent, reducing solvent usage and disposal costs. It has advantages in detection, allowing UV spectra to be monitored down to short wavelengths, as well as a compatibility with universal flame ionisation detection and mass spectroscopy. By employing deuterium oxide as the eluent, solvent free NMR spectra can be measured. The development of newer more thermally stable stationary phases, including hybrid phases, have expanded the analytes that can be examined and these now range from alkylbenzenes, phenols, alkyl aryl ketones and a number of pharmaceuticals to carboxylic acids, amino acids, and carbohydrates. Very few compounds have been found to be unstable during the analysis. The separation methods can be directly coupled to superheated water extraction providing a totally solvent free system for sample extraction and analysis.

  11. Fuzzy cascade control based on control's history for superheated temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Guangjun; LI Gang; SHEN Shuguang

    2007-01-01

    To address the characteristics of the large delay and uncertainty of superheated temperature,a new cascade control system is presented based on control's history.Based on the analysis of the control objects' dynamic characteristics,historical control information (substituting for the deviation change rate) is used as the basis for decision-making of the fuzzy control.Therefore,the changing trend of the controlled variable can be accurately reflected.Furthermore,a proportional component is introduced,the advantages of PID and fuzzy controllers are integrated,and the structure weaknesses of conventional fuzzy controllers are overcome.Simulation shows that this control method can effectively reduce the adverse impact of the delay on control effects and,therefore,exhibit strong adaptability by comparing the superheated temperature control system by this controller with PID and conventional fuzzy controllers.

  12. Superheated Droplet Detectors as CDM Detectors The SIMPLE Experiment

    CERN Document Server

    Collar, J I; Limagne, D; Waysand, G

    1996-01-01

    Superheated Droplet Detectors (SDDs) are becoming commonplace in neutron personnel dosimetry. Their total insensitivity to minimum ionizing radiation (while responsive to nuclear recoils of energies ~ few keV), together with their low cost, ease of production, and operation at room temperature and 1 atm makes them ideal for Cold Dark Matter (CDM) searches. SDD's are optimal for the exploration of the spin-dependent neutralino coupling due to their high fluorine content. The status of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) is presented. Under realistic background considerations, we expect an improvement in the present Cold Dark Matter sensitivity of 2-3 orders of magnitude after ~1 kg-y of data acquisition.

  13. Neutron - Alpha irradiation response of superheated emulsion detectors

    Science.gov (United States)

    Felizardo, M.; Morlat, T.; Girard, T. A.; Kling, A.; Fernandes, A. C.; Marques, J. G.; Carvalho, F.; Ramos, A. R.

    2017-08-01

    We report new experimental investigations of the response of single superheated emulsion detectors with small droplet (<30 μm radii) size distributions to both α- and neutron irradiations. Analysis of the results in terms of the underlying detector physics yields a toy model which reasonably reproduces the observations, and identifies the initial energy of the α in the liquid and distribution of droplet sizes as primarily responsible for the detector capacity to distinguish between nuclear recoil and α events.

  14. AUTOMATIC CONTROL SYSTEM OF THE DRUM BOILER SUPERHEATED STEAM TEMPERATURE.

    Directory of Open Access Journals (Sweden)

    Juravliov A.A.

    2006-04-01

    Full Text Available The control system of the temperature of the superheated steam of the drum boiler is examined. Main features of the system are the PI-controller in the external control loop and introduction of the functional component of the error signal of the external control loop with the negative feedback of the error signal between the prescribed value of steam flowrate and the signal of the steam flowrate in the exit of the boiler in the internal control loop.

  15. Criteria for the provision and assembly of the rotor blades of a 300 MW low pressure steam turbine for electrical generation; Criterios para el suministro y ensambles de la alabes de rotor de turbina de vapor de 300 MW baja presion para generacion electrica

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, Galo; Felix, Jorge A.; Quijano, Octavio [Especialistas en Turbopartes, S.A. de C.V., Queretaro, Queretaro (Mexico)

    2007-11-15

    This paper presents some of the main criteria to consider from the inspection, disassembling and assembly of blades with different root types of a turbine rotor of steam turbines for power generation, having as an aim to count on a reliable rotor, fulfilling with the equipment original design and norms and international standards. [Spanish] Este trabajo presenta algunos de los criterios principales a considerar desde la inspeccion, desmontaje y montaje de alabes de diferentes tipos de raiz de un rotor de turbinas de vapor de generacion electrica, teniendo como finalidad contar con un rotor confiable, cumpliendo con el diseno original del equipo y con normas y estandares internacionales.

  16. Dynamic behavior of superheated steam and ways of control

    Institute of Scientific and Technical Information of China (English)

    Xu LI

    2008-01-01

    A simple way of calculating the dynamic behavior of a superheater is presented. A comparison of the measured data with the calculated result verifies the accuracy of this simple method. It is the first time that a phase compensation for real roots, i.e., the twin lead/lag loop which is facile for engineering applications, is used in superheated steam temperature control. Numerous simu-lation results show that both the response time lapse and maximal dynamic deviation are greatly reduced. Moreover, a formula to calculate the setting parameters is presented, together with a practical example of its engineering application in superheated steam temperature control with single-stage attemperation in a power plant boiler. This method can remarkably improve the control performance of superheated steam temperature and makes it possible for one stage attemperation to be sufficient for the superheater of power plant boilers, thus simplifying the superheater system and reducing investment. Because the control performance is remarkably raised, the set values of the steam temperature control system can be raised above rated values and also the operational economy, without impairing the operation safety.

  17. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...... configurations are compared with each other. Technoeconomy is used when calculating the cost if the plants. It is found that when a solid oxide fuel cell plant is combined with a gas turbine cycle then the plant efficiency will be the highest one while if a biomass gasification plant is integrated...... with these hybrid cycles then integrated biomass gasification with solid oxide fuel cell and steam cycle will have the highest plant efficiency. The cost of solid oxide fuel cell with steam plant is found to be the lowest one with a value of about 1030$/kW....

  18. Development of a Parching Machine Using Super-Heated Vapor or Super-Heated High-Moisture Atmosphere

    Science.gov (United States)

    Sato, Shoichi; Shinsho, Seiji; Iriki, Hiroyuki; Asai, Junya; Suganuma, Hirofumi; Shibata, Tsutomu

    We developed a new parching machine with super-heated vapor or super-heated highmoisture atmosphere as a heat medium, and investigated the influence exerted on the characteristics of manufactured tea and crude tea quality. (1)We developed machine specifications that improved throughput and allowed us to control stable quality compared with the conventional kamairicha parching machine. (2)The new parching machine could not only manufacture like kamairicha but also achieve various degrees of steaming of products like green tea or heavily steamed sencha. (3)The new parching machine could not only deactivate enzymes but dry leaves. (4)The influence of throughput was great with respect to the grade of pan-parched flavour, which meant that there was a contact opportunity for tea leaves and the surface of machine's wall. (5)Unpleasant smells such as that produced in a summer crop of tea were reduced by the new parching machine.

  19. CO{sub 2} separation by carbonate looping including additional power generation with a CO{sub 2}-H{sub 2}O steam turbine

    Energy Technology Data Exchange (ETDEWEB)

    Strelow, M.; Schlitzberger, C.; Roeder, F.; Magda, S.; Leithner, R. [Technische Universitaet Braunschweig, Institut fuer Waerme- und Brennstofftechnik, Braunschweig (Germany)

    2012-03-15

    Usually the separation of CO{sub 2} from the flue gas in power plants is connected with high efficiency losses, independent of separation technology. The reason is that the separation processes of the pre- or post-combustion capture or using an oxy-fuel process as proposed today result in additional energy consumption. But there are also sorbents, e.g., lime, that form carbonates and release heat at a temperature level of about 600 C and will be calcinated at higher temperatures (about 900 C). Integration of these processes in the design of a conventional power plant and production of additional power output by integration of another Rankine cycle using the separated CO{sub 2} and steam minimizes efficiency losses. The simulation and the results of such a CO{sub 2} capture process are described in this paper. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Borosonic inspection and remaining useful operational life estimation of steam turbine rotors; Inspeccion borosonica y estimacion de vida remanente de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero P, Jose A; Dorantes G, Oscar; Munoz Q, Rodolfo; Serrano R, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    The turbo-generators used in the electric power generation frequently go through transitory operations (start ups, shut downs or power changes). Such actions cause that certain critical components of the turbines, such as rotors and casings, are put under cycles of repetitive stresses, which consume its useful life. The frequency whereupon these transitory thermal cycles happen result in the presence of high thermo-mechanical stresses that produce fatigue (damage) in the rotor material. With time, at the increase of the material fatigue, fissures form that can inclusively lead to severe, catastrophic faults. The borosonic inspection consists in introducing and positioning an automatic probe in the central drill of the rotor, this allows the non-destructive inspection with longitudinal ultrasonic beam, ultrasonic cross-sectional and ultrasonic superficial. This way, it is possible to detect and locate geometric discontinuities (superficial and volumetric), in at least 100 mm of depth from the drill surface in its entire periphery and throughout the rotor length. [Spanish] Los turbogeneradores empleados en la generacion de energia electrica con frecuencia realizan operaciones transitorias (arranques, paros o cambios de potencia). Acciones tales, provocan que ciertos componentes criticos de las turbinas, como los rotores y carcasas, sean sometidos a ciclos de esfuerzos repetitivos, lo que consume su vida util. La frecuencia con que ocurren estos ciclos termicos transitorios da como resultado la presencia de altos esfuerzos termomecanicos que producen una fatiga (dano) en el material del rotor. Con el tiempo, al incrementarse la fatiga del material, se forman fisuras que pueden conducir a fallas severas, catastroficas inclusive. La inspeccion borosonica consiste en introducir y posicionar una sonda automatica en el barreno central del rotor, ello permite la inspeccion no destructiva con haz ultrasonico longitudinal, haz ultrasonico transversal y haz ultrasonico

  1. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel...... enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a Heat Recovery Steam Generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

  2. Experimental investigation on rotating flow instabilities in the operation range of ventilation of a low pressure steam turbine; Experimentelle Untersuchung von rotierenden Stroemungsinstabilitaeten im Betriebsbereich der Ventilation einer Niederdruck-Dampfturbine

    Energy Technology Data Exchange (ETDEWEB)

    Gerschuetz, W.

    2006-07-01

    been observed in axial flow fans and compressors and is demonstrated here in an LP steam turbine operating at very low flow rates. (orig.)

  3. Useful life extension of steam-turbine elements by means of welding processes; Extension de la vida util de los elementos de las turbinas de vapor mediante procesos de soldadura

    Energy Technology Data Exchange (ETDEWEB)

    Mazur Czerwiec, Zdzislaw; Cristalinas Navarro, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1994-03-01

    The elements of the flow system in the steam turbines are subjected to a natural or accelerated wear during their operation. The stationary and the rotating blades are parts of the turbine that present damages, faults or materials wear, after some service periods, that can be from mechanical or metallurgical origin and prevent its continuous operation. This is also revealed in the equipment availability, reliability and performance diminution. Several cases are presented of recovery, and useful life extension of worn stationary blades (nozzle blocks and diaphragms), and rotating blades by means of welding processes executed in several fossil fuel power plants of Comision Federal de Electricidad. For each specific case, wear type or damage, the special processes based in welding processes, were developed. The blade recovery process also includes: the stress relieving, machining, special coating, quality control and tool design. Once the recovery process is completed, the components were installed back in the turbines for their utilization. The application of the welding technologies developed for blade recovery, represents just a fraction of the cost of new blades, that results in an economic saving. [Espanol] Los elementos del sistema de flujo de las turbinas de vapor sufren un desgaste natural o acelerado durante su operacion. Los alabes fijos y moviles son las partes de la turbina que despues de ciertos periodos de servicio presentan danos, fallas o desgaste del material que pueden ser de origen mecanico o metalurgico y no permiten su operacion continua. Esto se refleja tambien en la disminucion de la disponibilidad, confiabilidad y rendimiento del equipo. Se presentan varios casos de recuperacion y prolongacion de la vida util de alabes fijos (bloques de toberas y diafragmas) y moviles danados y gastados a causa de procesos de soldadura que se llevaron a cabo en varias plantas termoelectricas de la Comision Federal de Electricidad. Para cada caso especifico

  4. Investigations of the microstructural stability of wrought Ni-(Fe)-based syperalloys for steam turbine rotor application beyond 700 C; Untersuchungen der Strukturstabilitaet von Ni-(Fe)-Basislegierungen fuer Rotorwellen in Dampfturbinen mit Arbeitstemperaturen ueber 700 C

    Energy Technology Data Exchange (ETDEWEB)

    Seliga, T.

    2005-07-01

    There is a continuous trend to improve the efficiency of modern power plants with steam turbine require operating steam temperature from 700 to 720 C. For substantial parts like turbine rotors and discs this means increased requirements on the high temperature resistance, which can not longer be fulfilled by the presently used steel. As new materials for the components, which are thermo-mechanically loaded, only Ni-based superalloys are suitable for their fabrication, structure stability and thermo-mechanical characteristics. With view on creep and creep crack growth resistance as suitable candidates in the context a DFG research project wrought Ni-based superalloy Waspaloy and Ni-Fe-based alloy Inconel 706 were selected, which exhibited different hardening mechanisms. Waspaloy is a {gamma}'-hardened material with small portion of carbides on the grain boundaries. Inconel 706 is a particle hardened alloy with a very complex microstructure, it consists of {gamma}', {gamma}{sup ''}-particle, {eta}-phase und carbides. Concerning to their castability, forgeability, creep and creep crack growth and microstructural stability these candidate materials have been investigated and modelled. The knowledge about their long time stability of the microstructure, castability, forgeability and mechanical properties leads to the two new modification (Waspaloy{yields}DT750 and Inconel 706{yields}DT706). The modification of the Waspaloy to DT 750 served better castability (elimination of the Freckle formation). An improvement of the long-term stability of the microstructure was not necessary, by a changed heat treatment was reached a homogeneous, monomodale {gamma}'-particle distribution. The modification of Inconel 706 to DT 706 served to stabilize the {gamma}'-phase and to reduce of the {gamma}{sup ''} phase without suppressing the cellular {eta}-phase colonies on the grain boundaries. This work presents the test results for the structural

  5. Numerical Simulation on Aerodynamic Performance of Steam Turbine Exhaust Hood Coupling Last Stage Blade%耦合末级叶片的汽轮机排汽缸气动数值模拟

    Institute of Scientific and Technical Information of China (English)

    史立群; 杨建道; 杨锐; 彭泽瑛

    2011-01-01

    为研究末级叶片出口流场径向的不均匀性对排汽缸气动性能的影响,基于稳态的三维N—S方程、能量方程以及连续性方程,采用商业CFD软件进行了排汽缸气动性能的数值模拟计算.结果表明:耦合末级叶片的数值模拟计算结果更接近真实值;动叶叶顶漏气射流对排汽缸内的流动结构有很大影响,使得计算得出的静压恢复系数有所增加;叶片叶顶漏气影响不可忽略,在今后的排汽缸气动设计及优化工作中需要考虑末级叶片的影响;排汽缸进口条件对于其气动性能有着决定性的影响.%In order to study the influence of flow field non--uniformity at last blade exit of steam turbine on aerodynamic performance of its exhaust hood, a numerical simulation has been carried to analyze the aerodynamic performance based on 3D steady-state N-S and energy and continuity equations using commercial CFD software. Results show that the numerical simulation coupling last stage blade works out a result closer to the true value; the leakage jet at blade tip has a significant impact on flow field in the exhaust hood, which generally results in increased recovery coefficient of calculated static pressure; the effect of tip leakage cafft be neglected in future design and optimization concerning aerodynamic performance of the exhaust hood; the inlet condition of exhaust hood affects the aerodynamic performance decisively.

  6. nfluence of Water Marbles on Efficiency, Blade Fracture and Water Erosion of Steam Turbines%弹珠对汽轮机效率及叶片断裂、水蚀的影响

    Institute of Scientific and Technical Information of China (English)

    高德伟

    2012-01-01

    By analyzing the status of blade fracture and water erosion occurring in an extraction condensing turbine unit, the failure is found to be caused mainly by the braking force from water marbles, which inhibits the rotation of the rotor, and therefore directly affects the efficiency of the steam turbine. The formation mechanism of secondary water droplets from water marbles is compared with that from water films at blade trailing edge torn and broken by high-speed steam flows. It is pointed out that the number of water marbles can be effectively decreased by changing the structure of corresponding baffle plates, so as to reduce the mentioned braking force, economize the energy consumption, and therefore elongate the blade life and raise the unit efficiency.%通过对一台抽汽凝汽式汽轮机组叶片水蚀状况进行分析,提出导致叶片断裂和水蚀的主要原因是由弹珠所引起的“弹珠阻止转子旋转的制动力”,它会直接影响汽轮机效率.阐述了由“弹珠”所形成的二次水滴与叶片出汽边处的“水膜”被高速汽流撕裂和破碎所形成的二次水滴的区别.指出利用一定的科学技术手段,改变隔板的结构形式可以有效地减少弹珠的生成数量,减小损耗,减小和抑制“弹珠阻止转子旋转的制动力”,从而达到提高机组效率、延长叶片使用寿命的目的.

  7. Design and construction of a height caliper of labyrinths seals of high power steam turbines; Diseno y construccion de un calibrador de alturas para sellos laberintos de turbinas de vapor de alta potencia

    Energy Technology Data Exchange (ETDEWEB)

    Quinonez Osuna, Jose R. [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico); Mazur Czerwiec, Zdzislaw [instituto de Investigaciones Electicas, Cuernavaca, Morelos (Mexico); Valdez Valdez, Omar [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico)

    2007-11-15

    This article presents the development of a new instrument that allows calibrating with exactness the labyrinths seals height of the radial type, normally used in steam turbines and many other turbo-machines. The calibration process derived from the application of the designed instrument is distinguished from the existing one in the fact of considering a perpendicularity reference that allows high exactness in the measurement of height differences (0,008 mm), which is performed at the moment of adjusting the steam seals each time that its sheets are substituted for new ones. Such characteristic, allows therefore, higher efficiency conditions, stability and trustworthiness in the unit operation, once maintenance of this kind has been applied to it. The lack of monitoring and periodic maintenance of the gaps between seals and rotor constitutes the main cause of efficiency loss in power plant turbines installed in Mexico, generating wastes of up to 4% of its capacity, which represents 15 MW in high power units. [Spanish] El articulo representa el desarrollo de un nuevo instrumento que permite calibrar con exactitud las alturas de los sellos laberinticos de tipo radial, ordinariamente empleados en turbinas de vapor y en muchas otras turbo-maquinas. El proceso de calibracion derivado de la aplicacion del instrumento disenado se distingue del existente, en el hecho de considerar una referencia de perpendicularidad que permite alta precision en la medicion de diferencias de altura (0.008 mm.), lo cual es realizado en el momento de ajustar los sellos de vapor cada vez que sus laminas son sustituidas por nuevas. Dicha caracteristica, procura por ende condiciones mayores de eficiencia, estabilidad y confiabilidad en la operacion de la unidad, una vez que le ha sido brindado un mantenimiento de esta naturaleza. La falta de monitoreo y mantenimiento periodico de los claros entre sellos y rotor, constituye la principal causa de perdida de eficiencia en las turbinas de las

  8. Numerical Simulation Study on IP Rotor Coding Coupled Heat Transfer of 1000MW Ultra-supercritical Steam Turbine%1000MW超超临界汽轮机中压转子冷却耦合换热数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    杨明; 李长宝; 管继伟; 刘云峰

    2013-01-01

    By using CFD and conjugate heat transfer(CHT) methods,IP Rotor Cooling of 1000MW Ultra-supercritical Steam Turbine has been numerical simulated.The temperature distribution whether the fluid and solid coupled heat transfer,cooling steam temperature effects on IP Rotor and the temperature distribution of the two half-rotor have been investigated.The fluid and solid temperature field distribution characteristics has been more realistic simulated.This article can provide a reliable basis for the structural design of ultra-supercritical steam turbine.%通过采用CFD和CHT(共轭换热)的数值方法,对超超临界1000MW汽轮机中压转子冷却进行了数值模拟,研究了有无流体与固体耦合换热的温度场分布差别,冷却蒸汽温度对中压转子冷却效果的影响,中压二级半转子冷却的温度分布,较真实地模拟了流体、固体区域温度场的分布特性.

  9. a Theoretical Model of a Superheated Liquid Droplet Neutron Detector.

    Science.gov (United States)

    Harper, Mark Joseph

    Neutrons can interact with the atoms in superheated liquid droplets which are suspended in a viscous matrix material, resulting in the formation of charged recoil ions. These ions transfer energy to the liquid, sometimes resulting in the droplets vaporizing and producing observable bubbles. Devices employing this mechanism are known as superheated liquid droplet detectors, or bubble detectors. The basis of bubble detector operation is identical to that of bubble chambers, which have been well characterized by researchers such as Wilson, Glaser, Seitz, and others since the 1950's. Each of the microscopic superheated liquid droplets behaves like an independent bubble chamber. This dissertation presents a theoretical model which considers the three principal aspects of detector operation: nuclear reactions, charged particle energy deposition, and thermodynamic bubble formation. All possible nuclear reactions were examined and those which could reasonably result in recoil ions sufficiently energetic to vaporize a droplet were analyzed in detail. Feasible interactions having adequate cross sections include elastic and inelastic scattering, n-proton, and n-alpha reactions. Ziegler's TRansport of Ions in Matter (TRIM) code was used to calculate the ions' stopping powers in various compounds based on the ionic energies predicted by standard scattering distributions. If the ions deposit enough energy in a small enough volume then the entire droplet will vaporize without further energy input. Various theories as to the vaporization of droplets by ionizing radiation were studied and a novel method of predicting the critical (minimum) energy was developed. This method can be used to calculate the minimum required stopping power for the ion, from which the threshold neutron energy is obtainable. Experimental verification of the model was accomplished by measuring the response of two different types of bubble detectors to monoenergetic thermal neutrons, as well as to neutrons

  10. Thermodynamic Investigation of an Integrated Gasification Plant with Solid Oxide Fuel Cell and Steam Cycles

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2012-01-01

    A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas...... was rather clean for feeding to the SOFC stacks after a simple cleaning step. Because all the fuel cannot be burned in the SOFC stacks, a burner was used to combust the remaining fuel. The off-gases from the burner were then used to produce steam for the bottoming steam cycle in a heat recovery steam...... generator (HRSG). The steam cycle was modeled with a simple single pressure level. In addition, a hybrid recuperator was used to recover more energy from the HRSG and send it back to the SOFC cycle. Thus two different configurations were investigated to study the plants characteristic. Such system...

  11. Study of low frequency acoustic signals from superheated droplet detector

    CERN Document Server

    Mondal, P K; Das, M; Bhattacharjee, P

    2013-01-01

    The bubble nucleation process in superheated droplet detector (SDD) is associated with the emission of an acoustic pulse that can be detected by an acoustic sensor. We have studied the neutron and gamma-ray induced nucleation events in a SDD with the active liquid R-12 (CCl2F2, b.p. -29.8oC) using a condenser microphone sensor. A comparative study in the low frequency region (~ 0-10kHz) for the neutron and gamma-ray induced nucleation is presented here. From the analysis of the waveforms we observe a significant difference between the neutron and gamma-ray induced acoustic events.

  12. Applicability of superheated drop (bubble) detectors to reactor dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F.; Curzio, G. [Univ. degli Studi di Pisa (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Alberts, W.G. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Apfel, R.E.; Guldbakke, S. [Yale Univ., New Haven, CT (United States). Dept. of Mechanical Engineering

    1994-12-31

    The characteristics of superheated drop (bubble) detectors (SDD`s) have been reviewed with respect to the possible application of these devices in reactor dosimetry. In particular, their ability to measure neutrons in the presence of a high noise level, elevated temperatures and intense {gamma} background has been investigated. Based on these studies, the use of SDD`s is proposed for the monitoring and analysis of neutron emission from spent fuel assemblies. Finally, the possibility to employ these detectors in radiation protection dosimetry around power plants is discussed.

  13. Neutron-gamma discrimination by pulse analysis with superheated drop detector

    CERN Document Server

    Das, Mala; Saha, S; Bhattacharya, S; Bhattacharjee, P

    2010-01-01

    Superheated drop detector (SDD) consisting of drops of superheated liquid of halocarbon is irradiated to neutrons and gamma-rays from 252Cf fission neutron source and 137Cs gamma source separately. The analysis of pulse height of the signals in the neutron and gamma-ray sensitive temperature provides strong information on the identification of neutron and gamma-ray induced events.

  14. Superheated Water-Cooled Small Modular Underwater Reactor Concept

    Directory of Open Access Journals (Sweden)

    Koroush Shirvan

    2016-12-01

    Full Text Available A novel fully passive small modular superheated water reactor (SWR for underwater deployment is designed to produce 160 MWe with steam at 500ºC to increase the thermodynamic efficiency compared with standard light water reactors. The SWR design is based on a conceptual 400-MWe integral SWR using the internally and externally cooled annular fuel (IXAF. The coolant boils in the external channels throughout the core to approximately the same quality as a conventional boiling water reactor and then the steam, instead of exiting the reactor pressure vessel, turns around and flows downward in the central channel of some IXAF fuel rods within each assembly and then flows upward through the rest of the IXAF pins in the assembly and exits the reactor pressure vessel as superheated steam. In this study, new cladding material to withstand high temperature steam in addition to the fuel mechanical and safety behavior is investigated. The steam temperature was found to depend on the thermal and mechanical characteristics of the fuel. The SWR showed a very different transient behavior compared with a boiling water reactor. The inter-play between the inner and outer channels of the IXAF was mainly beneficial except in the case of sudden reactivity insertion transients where additional control consideration is required.

  15. LET dependence of bubbles evaporation pulses in superheated emulsion detectors

    Science.gov (United States)

    Di Fulvio, Angela; Huang, Jean; Staib, Lawrence; d'Errico, Francesco

    2015-06-01

    Superheated emulsion detectors are suspensions of metastable liquid droplets in a compliant inert medium. Upon interaction with ionizing radiation, the droplets evaporate, generating visible bubbles. Bubble expansion associated with the boiling of the droplets is accompanied by pressure pulses in both the sonic and ultrasonic frequency range. In this work, we analyzed the signal generated by bubble evaporation in the frequency and time domain. We used octafluoropropane (R-218) based emulsions, sensitive to both photons and neutrons. The frequency content of the detected pulses appears to extend well into the hundreds of kHz, beyond the range used in commercial devices to count bubbles as they are formed (typically 1-10 kHz). Kilohertz components characterize the early part of the waveforms, potentially containing information about the energetics of the explosive bubble initial growth phase. The power spectral density of the acoustic signal produced by neutron-induced evaporation shows a characteristic frequency pattern in the 200-400 kHz range, which is not observed when bubbles evaporate upon gamma ray-induced irradiation. For practical applications, detection of ultrasonic pulses associated with the boiling of the superheated drops can be exploited as a fast readout method, negligibly affected by mechanical ambient noise.

  16. Fundamental Properties of Superheated Drop (Bubble) Detectors (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F

    1999-07-01

    Superheated drop detectors and bubble damage detectors find increasing applications in ionising radiation dosimetry and spectrometry. These emulsions of overexpanded halocarbon droplets can be manufactured to respond selectively to densely ionising particles, such as neutron recoils, or to all directly and indirectly ionising radiations. It is shown here that the fundamental properties of the detectors can be predicted by semi-empirical expressions based on the thermal spike theory. A new non-dimensional quantity, defined as 'reduced superheat', is introduced and shown to permit a unified parametrisation of the properties of superheated emulsions. In particular, utilising the reduced superheat concept, it is possible to predict the neutron detection thresholds of the emulsions, their sensitisation to thermal neutrons and to photons, and their ultimate thermodynamic instability. This unified characterisation finds immediate application in the selection of the halocarbons and of the operating conditions most suitable for specific radiation detection problems. Finally, some data are presented which question a direct proportionality between the particle track length contributing to the vaporisation and a critical bubble diameter derived from spontaneous nucleation models. An effective track length based on experimental observations is introduced to derive the minimum track-averaged LET for bubble nucleation expressed as a function of reduced superheat. (author)

  17. Combinations of solid oxide fuel cell and several enhanced gas turbine cycles

    Science.gov (United States)

    Kuchonthara, Prapan; Bhattacharya, Sankar; Tsutsumi, Atsushi

    Combined power generation systems with combinations of solid oxide fuel cell (SOFC) and various enhanced gas turbine (GT) cycles were evaluated. In the GT part, steam injected gas turbine (STIG) cycle, GT/steam turbine (ST) combined cycle, and humid air turbine (HAT) cycle were considered. Moreover, additional recuperation was considered by means of air preheating (APH) in the STIG cycle. Effects of operating turbine inlet temperature (TIT) and pressure ratio (PR) on overall system performance were assessed. Although the SOFC-HAT system shows the lowest specific work output compared to other systems, its highest thermal efficiency presents a significant advantage. Furthermore, at high TITs and PRs the SOFC-HAT system gives the best performance in terms of both thermal efficiency and specific work. Results indicate that energy recuperative features in the HAT promote the positive effect of increasing TIT by means of enhancing GT efficiency, leading to the improvement in thermal efficiency of the overall system.

  18. H gas turbine combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Corman, J. [General Electric Co., Schenectady, NY (United States)

    1995-10-01

    A major step has been taken in the development of the Next Power Generation System - {open_quotes}H{close_quotes} Technology Combined Cycle. This new gas turbine combined-cycle system increases thermal performance to the 60% level by increasing gas turbine operating temperature to 1430 C (2600 F) at a pressure ratio of 23 to 1. Although this represents a significant increase in operating temperature for the gas turbine, the potential for single digit NOx levels (based upon 15% O{sub 2}, in the exhaust) has been retained. The combined effect of performance increase and environmental control is achieved by an innovative closed loop steam cooling system which tightly integrates the gas turbine and steam turbine cycles. The {open_quotes}H{close_quotes} Gas Turbine Combined Cycle System meets the goals and objectives of the DOE Advanced Turbine System Program. The development and demonstration of this new system is being carried out as part of the Industrial/Government cooperative agreement under the ATS Program. This program will achieve first commercial operation of this new system before the end of the century.

  19. Analysis and Management of Steam- excited Vibration Fault of a Certain 300MW Steam Turbine%某台300MW机组汽流激振故障的分析和处理

    Institute of Scientific and Technical Information of China (English)

    崔亚辉; 张俊杰; 徐福海; 毕春海; 温武斌; 陈荣轩

    2012-01-01

    Hie vibration of a certain 300MW steam turbine was effected by the opening order and size of control valve obviously,the vibration characteristics and the steam force which originated from control valve were analyzed,and the results showed that the vibration of unit could not be decreased or eliminated by increasing the load of journal, the load of journal could be adjusted by steam force which originated from the opening order of control valve. On the contrary, it increased the vibration of unit. The reason was that the radial position of rotor which located in casing had changed, and then the clearance of overcross section was changed. The offset of rotor was decreased by applying reasonable opening order and size of control valve, although the eccentricity and load of journal were decreased, the vibration was decreased obviously. Therefore,there are several methods to inhibit steam-excited vibration,the contradiction may occur when some methods are implemented on site. Firstly,it need to analyze the main factor which arouses steam-excited vibration,the satisfactory effect can be gained by applying key management.%某台300MW汽轮机的振动明显受到调门开启顺序和开度大小的影响,通过对机组的振动特征以及调门产生的汽流力进行分析、研究发现:采用调整阀门的开启顺序产生汽流力来提高轴承载荷并不能减小或消除该机组的振动,反而增大了机组的振动;原因是转子在汽缸中的径向位置发生了变化,改变了通流部分的间隙;通过采取合理的调门开启顺序和开度减小转子在汽缸中的偏移,虽然轴承偏心率减小、轴承载荷下降,但是振动水平明显降低了.由此可知,抑制汽流激振的方法有若干种,有些方法在现场实施起来可能会出现矛盾,此时首先需分析引起汽流激振的主要因素,然后采取能解决问题的关键措施,才能取得满意的效果.

  20. 神经网络算法在汽轮机排汽焓估算中的应用%Application of neural network algorithm in steam turbine's exhaust enthalpy estimation

    Institute of Scientific and Technical Information of China (English)

    吴俊杰; 侯宏娟; 杨勇平

    2014-01-01

    The dryness of turbine's exhaust steam can hardly be obtained via direct measurements in online performance calculation of thermal system,for the steam is usually in wet state.The artificial's neural net-works was established to calculate the exhaust enthalpy of steam turbine.By analyzing the main factors af-fecting the exhaust enthalpy and transforming the original data into non-dimensional parameters,the calcu-lation speed and accuracy were compared by using different training functions in Back-Propagation (BP) neural network.Meanwhile,the accuracy of the BP Neural Network and the Radial Basis Function (RBF) network was compared as well.Consequently,when calculating the exhaust enthalpy,the BP neural net-work depends strongly on training functions,some of which will result in strong random and low calcula-tion speed.After the research,three of the training functions:'traingdx','trainscg'and'trainoss',have the ad-vantages of both fast calculation speed and high accuracy.The RBF network has the advantages of faster calculation speed and weaker dependence on training functions but the disadvantage of lower accuracy,com-pared with the BP neural network.The error will be diminished when enough training samples are provid-ed.%在线机组热力系统性能计算中,汽轮机的排汽通常处于湿蒸汽区,排汽干度目前无法实现直接测量。对此,将神经网络方法应用于汽轮机排汽焓的估算,通过分析汽轮机排汽焓的影响因素,并对数据进行无量纲化处理,对BP神经网络在不同训练函数下的计算精度与速度,以及BP神经网络与RBF神经网络计算排汽焓的准确度进行比较。结果表明:BP 神经网络对训练函数的依赖程度较大,部分函数在计算中随机性较强、计算时间较长;traingdx、trainscg和trainoss 3个函数计算时间较短、计算精度较高,可作为训练函数;RBF神经网络的计算误差较BP神经网络大,但其自适应能力强,

  1. Economic evaluation of externally fired gas turbine cycles for small-scale biomass cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    In this conceptual study, externally fired gas turbine (EFGT) cycles in combination with a biomass-fueled, atmospheric circulating fluidized bed (CFB) furnace are investigated for small scale heat and power production ({approx} 8 MW fuel input). Three cycle configurations are considered: closed cycle, with nitrogen, helium, and a helium/carbon dioxide mixture as working fluids; open cycle operating in parallel to the CFB system; and open cycle with a series connection to the CFB system. Intercooling, postcooling, and recuperation are employed with the goal of maximizing efficiency. Aside from a thermodynamic performance analysis, the study includes an economic analysis of both the closed and open externally fired gas turbine configurations, and comparisons are made with existing and emerging alternatives for small-scale biomass cogeneration. Simulation results show that thermodynamic performance varies slightly between the different configurations and working fluids, with electrical efficiencies of 31-38% (LHV) and total efficiency of 85-106% (LHV). The economic evaluation shows that the turbomachinery and the CFB furnace dominate the total plant cost, with each contributing about 1/3 of the total installed equipment cost. The specific capital cost for installation in Sweden in 1998 currency is calculated as 26-31 kSEK/kW{sub e} which is equivalent to 3 200-3 900 USD/kW{sub e} or 2 700-3 300 EUR/kW{sub e} .The cost of electricity, COE, is estimated to 590-670 SEK/MWh{sub e} (equivalent to 73-84 USD/MWh{sub e} or 62-71 EUR/MWh{sub e}) for 4 000 full load hours per year in a cogeneration application. Comparing the economic results for the externally fired gas turbine cycles in a slightly larger scale (40-50 MW{sub f}) to the economics of conventional biomass fired steam turbine cycles shows that the cost of electricity for the two plant configurations are roughly the same with a COE of 300-350 SEK/MWh{sub e}. It is believed that the economic performance of the EFGT

  2. Analysis and Optimization of a Compressed Air Energy Storage—Combined Cycle System

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-06-01

    Full Text Available Compressed air energy storage (CAES is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional CAES combined with a steam turbine cycle by waste heat boiler. Simulation and thermodynamic analysis are carried out on the proposed CAES-CC system. The electricity and heating rates of the proposed CAES-CC system are lower than those of the conventional CAES by 0.127 kWh/kWh and 0.338 kWh/kWh, respectively, because the CAES-CC system recycles high-temperature turbine-exhausting air. The overall efficiency of the CAES-CC system is improved by approximately 10% compared with that of the conventional CAES. In the CAES-CC system, compressing intercooler heat can keep the steam turbine on hot standby, thus improving the flexibility of CAES-CC. This study brought about a new method for improving the efficiency of CAES and provided new thoughts for integrating CAES with other electricity-generating modes.

  3. Phase transition time delays in irradiated superheated superconducting granules

    CERN Document Server

    Abplanalp, M; Czapek, G; Diggelmann, U; Furlan, M; Gabutti, A; Janos, S; Moser, U; Pozzi, R; Pretzl, Klaus P; Schmiemann, K; Perret-Gallix, D; Van den Brandt, B; Konter, J A; Mango, S

    1994-01-01

    The time difference between a particle interaction in a Superheated Superconducting Granule (SSG) and the resulting phase transition signal has been explored. Detectors containing Zn and Sn SSG were irradiated with neutrons and protons to study the heating mechanism taking place in nuclear recoil and ionizing events. Scattered neutrons have been detected by a scintillator hodoscope behind the SSG with a recoil energy measurement resolution of 10\\% and an interaction time resolution of 1ns. The fast transition of the metastable granules allowed to determine the elapsed time between an energy deposition and the phase transition signal. In the case of Sn granules, the results show that the time distributions are narrow and independent of the deposited energy in nuclear recoil and ionizing events. In Zn, however, the time distributions are much broader and depend on the energy deposition in the granule.

  4. Aquathermolysis of conventional heavy oil with superheated steam

    Institute of Scientific and Technical Information of China (English)

    Song Guangshou; Zhou Tiyao; Cheng Linsong; Wang Yunxian; Tian Guoqing; Pi Jian; Zhang Zheng

    2009-01-01

    This paper presents a new aquathermolysis study of conventional heavy oil in superheated steam. A new high temperature autoclave was designed, where volume and pressure could be adjusted. Aquathermolysis was studied on two different conventional heavy oil samples under different reaction times and temperatures. Experimental results show that aquathermolysis does take place for conventional heavy oil. As reaction time increases, the oil viscosity reduces. However, the reaction will reach equilibrium after a certain period of time and won't be sensitive to any further reaction time any more. Analysis shows that, while resin and asphaltenes decrease, saturated hydrocarbons and the H/C ratio increase after reaction. The main mechanism of aquathermolysis includes hydrogenization, desulfuration reaction of resin and asphaltenes, etc.

  5. Neutron ambient dosimetry with superheated drop (bubble) detectors

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F.; Noccioni, P. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Alberts, W.G.; Dietz, E.; Siebert, B.R.L. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Gualdrini, G. [ENEA, Bologna (Italy); Kurkdjian, J. [CEA Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    A prototype neutron area monitor was developed which improves the performance of superheated drop detectors based on halocarbon-12. The detectors are thermally controlled: this removes external temperature effects while ensuring a dose equivalent response optimised with respect to its energy dependence. The system was first characterised through calibrations with monoenergetic neutron beams. In the intermediate energy range, where experimental investigations were not possible, Monte Carlo response calculations were carried out. The prototype was then extensively tested by means of simulated and in-field irradiations with broad neutron spectra. All these tests indicated a remarkably constant dose equivalent response regardless of the neutron energy distributions. The current device is a fairly delicate system which can be operated reliably when environmental conditions are not extreme. Nevertheless, when it was possible to employ it, this monitor demonstrated an accuracy far superior to that of conventional meters used in routine surveillance. (author).

  6. Rewetting of a low superheated rod with saturated water

    Energy Technology Data Exchange (ETDEWEB)

    Portillo, O.; Reyes, R.; Wayner, P.C. Jr.

    1999-07-01

    The study of the rewetting of a superheated surface has application in several technological fields. It is related to the control mechanism for loss of coolant accident (LOCA) in nuclear reactors. An adsorption model as the precursory mechanism for rewetting of a superheated surface is extended from its application to non-polar liquids to a polar fluid, and modeling calculations are compared with experimental data found in the literature. The adsorption model is based on interfacial forces acting at the tip of the rewetting front, the three-phase region. In this region, solid, liquid and vapor interfaces generate a contact angle that depends on the degree of superheat and describes the velocity of rewetting. The contact angle is a function of interfacial forces calculated through the disjoining pressure of the adsorbed film precursory of the rewetting. The influences of van der Waals and electrostatic intermolecular forces in the film thickness are analyzed. The authors find that the order of magnitude of the film thickness in the controlling region is of a few angstroms: thus, only van der Waals intermolecular forces define the interactions. For the prediction of the velocity of rewetting the temperature profile along the rod's surface is required and a one-dimensional and a two-dimensional heat conduction balances are solved. The thermophysical properties in the adsorption model are predicted by ASPEN PLUS data bank and from ASME steam tables. Variations of the predicted values have a strong influence on the results. The surface boundary condition on the rod contains an evaporative heat transfer coefficient that is calculated from the fitted experimental rewetting velocities and the two-dimensional temperature field in the rod. Using this calculation scheme the values of the evaporative heat transfer coefficient are obtained in the normal range of values. Therefore the adsorption model gives results that are consistent with experimental observations.

  7. 国产200 MW汽轮机转子在线热应力 监测与寿命管理%On-line Monitoring of Rotor Thermal Stresses and Service Life Management for a Chinese-made 200 MW Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Through the use of an object-oriented language the authors have developed a software designed for the on-line monitoring of rotor stresses and service life management for a Chinese-made 200 MW steam turbine. In addition to thermal stress monitoring the software is also capable of abnormal data inquiry, offering guidance for start-up and shutdown operations as well as their recollection, etc.%使用面向对象的语言,开发了国产200 MW汽轮机转子的在线热应力监测与寿命管理软件,该软件具有热应力监测、异常数据查询、启停指导和启停追忆等功能。

  8. 基于ICEM CFD对汽轮机末级三维叶片流场网格划分方法的优化%Optimization of Mesh Generation of Steam Turbine Last Stage 3D Blade Field Based on ICEM CFD

    Institute of Scientific and Technical Information of China (English)

    王纯; 刘艳梅; 周涛; 余兴刚; 谢诞梅

    2012-01-01

    网格的划分是对工程问题进行数值模拟的重要环节,网格质量的高低直接影响计算结果的精度.在对汽轮机叶片周围流场的数值模拟过程中,较高质量的网格是基础要求,但由于汽轮机末级叶片结构非常复杂,这就加大了其网格划分过程中的难度.为了进一步提高ICEM CFD对汽轮机叶片周围流场网格划分的质量,并针对避免产生“负体积”的问题.提出了一种可以得到高质量网格的方法,并阐述了在实际操作中应该注意的事项.%The mesh generation is an important part of the numerical simulation of engineering problems. Ihe quality ot the grid directly affects the accuracy of the calculation result. The last stage turbine blade has a very complicated structure, which increase the difficulty in the process of grids partition. However,the flow field computation around the steam turbine blade needs higher quality grid. In order to improve the grid quality of the flow field around steam turbine blades with ICEM CFD and to avoid "negative volume" , this paper puts forward a method which can generate high-quality grids . What' s more,it illustrates what matters should be paid attention to in practice.

  9. Medium-Range Order Structure and Fragility of Superheated Melts of Amorphous CuHf Alloys

    Institute of Scientific and Technical Information of China (English)

    BIAN Xiu-Fang; SUN Bao-An; HU Li-Na

    2006-01-01

    @@ The structural factors of amorphous CuHf alloys at different temperatures are determined by using a high temperature x-ray diffractometer. It is found that not only the short-range order structure but also the medium-range order structure exists in amorphous CuHf alloys. The dynamic viscosities of CuHf alloy melts are measured by a torsional oscillation viscometer. The fragility of superheated melts of CuHf alloys is calculated based on the viscosity data. The experimental results show that the glass-forming ability of the CuHf alloys is closely related to the fragility of their superheated melt. The relationship between the medium-range order structures and the fragility of superheated melts has also been established in amorphous CuHf alloys. In contrast to the fragility of supercooled liquids, the fragility of superheated liquids promises a better approach to reflecting the dynamics of glass forming liquids.

  10. Study of acoustic emission due to vaporisation of superheated droplets at higher pressure

    Science.gov (United States)

    Sarkar, Rupa; Mondal, Prasanna Kumar; Chatterjee, Barun Kumar

    2017-08-01

    Bubble nucleation in superheated liquids can be controlled by adjusting the ambient pressure and temperature. At higher pressure the threshold energy for bubble nucleation increases, and we have observed that the amplitude of the acoustic emission during vaporisation of superheated droplet decreases with increase in pressure at any given temperature. Other acoustic parameters such as the primary harmonic frequency and the decay time constant of the acoustic signal also decrease with increase in pressure. This behavior is independent of the type of superheated liquid. The decrease in signal amplitude limits the detection of bubble nucleation at higher pressure. This effect is explained by the emission of shockwave generated during the supersonic growth of the microbubble in superheated liquids.

  11. Life cycle assessment study of solar PV systems: An example of a 2.7kW{sub p} distributed solar PV system in Singapore

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, R.; Leong, K.C.; Osman, R.; Ho, H.K. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Tso, C.P. [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450 Melaka (Malaysia)

    2006-05-15

    In life cycle assessment (LCA) of solar PV systems, energy pay back time (EPBT) is the commonly used indicator to justify its primary energy use. However, EPBT is a function of competing energy sources with which electricity from solar PV is compared, and amount of electricity generated from the solar PV system which varies with local irradiation and ambient conditions. Therefore, it is more appropriate to use site-specific EPBT for major decision-making in power generation planning. LCA and life cycle cost analysis are performed for a distributed 2.7kW{sub p} grid-connected mono-crystalline solar PV system operating in Singapore. This paper presents various EPBT analyses of the solar PV system with reference to a fuel oil-fired steam turbine and their greenhouse gas (GHG) emissions and costs are also compared. The study reveals that GHG emission from electricity generation from the solar PV system is less than one-fourth that from an oil-fired steam turbine plant and one-half that from a gas-fired combined cycle plant. However, the cost of electricity is about five to seven times higher than that from the oil or gas fired power plant. The environmental uncertainties of the solar PV system are also critically reviewed and presented. (author)

  12. Ginzburg-Landau theory of the superheating field anisotropy of layered superconductors

    Science.gov (United States)

    Liarte, Danilo B.; Transtrum, Mark K.; Sethna, James P.

    2016-10-01

    We investigate the effects of material anisotropy on the superheating field of layered superconductors. We provide an intuitive argument both for the existence of a superheating field, and its dependence on anisotropy, for κ =λ /ξ (the ratio of magnetic to superconducting healing lengths) both large and small. On the one hand, the combination of our estimates with published results using a two-gap model for MgB2 suggests high anisotropy of the superheating field near zero temperature. On the other hand, within Ginzburg-Landau theory for a single gap, we see that the superheating field shows significant anisotropy only when the crystal anisotropy is large and the Ginzburg-Landau parameter κ is small. We then conclude that only small anisotropies in the superheating field are expected for typical unconventional superconductors near the critical temperature. Using a generalized form of Ginzburg Landau theory, we do a quantitative calculation for the anisotropic superheating field by mapping the problem to the isotropic case, and present a phase diagram in terms of anisotropy and κ , showing type I, type II, or mixed behavior (within Ginzburg-Landau theory), and regions where each asymptotic solution is expected. We estimate anisotropies for a number of different materials, and discuss the importance of these results for radio-frequency cavities for particle accelerators.

  13. Neutron spectrometry in mixed fields: superheated drop (bubble) detectors.

    Science.gov (United States)

    d'Errico, F; Matzke, M

    2003-01-01

    The BINS neutron threshold spectrometer permits the analysis of the main features of a neutron field for radiation protection purposes. The system offers a virtually complete photon discrimination and nested threshold responses to neutrons, which allow the use of very effective 'few-channel' unfolding procedures. To date, the practical operating energy range of a BINS is 0.1-10 MeV, over which a resolving power of 20-30% can be expected when the deconvolution is performed without explicit pre-information. Spectrum unfolding results in relatively high uncertainties on the differential fluence distributions, but due to negative correlations in adjacent energy groups the uncertainties on integral quantities such as dose equivalent are small and of the order of 5% to 10%, similar to the results of other active spectrometers. In comparison with most radiation detectors, the BINS is an extremely slow system due to the intrinsic duration of a bubble pulse and to the time associated with pulse analysis. For example, the maximum sustainable fluence rate of 1 MeV neutrons is about 10(4) cm(-2) s(-1), which is low for many neutron physics experiments. However, this rate corresponds to an ambient dose equivalent rate of about 1 mSv h(-1), making the active device adequate for radiation protection applications in the workplaces described in Section 1. There are ample margins for improvement of the spectrometer. In particular, in the low-energy region a thermal-epithermal neutron group may be added by using chlorine-bearing emulsions stabilised at suitable temperatures. In fact, the latest version of the system achieves this goal by using a single superheated emulsion of dichlorotetrafluoroethane (R-114) operated at temperatures up to 55 degrees C. This extends the range of the spectrometer and at the same time removes the undue enhancement of the UNFANA output in the low energy region. Above 10 MeV, the resolution can be improved by adding more thresholds, e.g. by starting from

  14. A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

    Directory of Open Access Journals (Sweden)

    Jesper Graa Andreasen

    2017-04-01

    Full Text Available This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt % and low-sulfur (0.5 wt % fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane, toluene, n-pentane, i-pentane and c-pentane. The results of the comparison indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit turbines compared to the steam turbines. When the efficiency of the c-pentane turbine was allowed to be 10% points larger than the steam turbine efficiency, the organic Rankine cycle unit reaches higher net power outputs than the steam Rankine cycle unit at all engine loads for the low-sulfur fuel case. The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The steam Rankine cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine cycle unit using MM produces 33% more power.

  15. Planning for hybrid-cycle OTEC experiments using the HMTSTA test facility at the Natural Energy Laboratory of Hawaii

    Science.gov (United States)

    Panchal, C.; Rabas, T.; Genens, L.

    The U.S. Department of Energy has built an experimental apparatus for studying the open-cycle Ocean Thermal Energy Conversion (OC-OTEC) system. Experiments using warm and cold seawater are currently underway to validate the performance predictions for an OC-TEC flash evaporator, surface condenser, and direct-contact condenser. The hybrid cycle is another OTEC option that produces both power and desalinated water, it is comparable in capital cost to OC-OTEC, and it eliminates the problems associated with the large steam turbine. Means are presented or modifying the existing apparatus to conduct similar experiments on hybrid-cycle OTEC heat exchangers. These data are required to validate predictive methods of the components and for the system integration that were identified in an earlier study of hybrid-cycle OTEC power plants.

  16. Issues related to waste sewage sludge drying under superheated steam

    Directory of Open Access Journals (Sweden)

    Hamawand Ihsan

    2015-12-01

    Full Text Available Sewage sludge was dried in a rotary drum dryer under superheated steam. Particle size and moisture content were shown to have significant influences on sticking and agglomeration of the materials. Pouring partially dried sludge (70–80% moisture content, wet basis directly into the screw feeder of the drum dryer resulted in a significant sticking to the surface of the drum and the final particle size of the product was greater than 100 mm in diameter. The moisture content of this product was slightly less than its initial value. To overcome this issue, the sludge was mixed with lignite at variety ratios and then chopped before being introduced to the feeding screw. It was found that mixing the sludge with lignite and then sieving the chopped materials through a four millimetre mesh sieve was the key to solve this issue. This technique significantly reduced both stickiness and agglomeration of the material. Also, this enabled for a significant reduction in moisture content of the final product.

  17. Microwave superheated water extraction of polysaccharides from spent coffee grounds.

    Science.gov (United States)

    Passos, Cláudia P; Coimbra, Manuel A

    2013-04-15

    The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source of polysaccharides. In the present work, the feasibility of microwave superheated water extraction of polysaccharides from SCG was studied. Different ratios of mass of SCG to water, from 1:30 to 1:5 (g:mL) were used for a total volume of 80 mL. Although the amount of material extracted/batch (MAE1) increased with the increase of the concentration of the sample, the amount of polysaccharides achieved a maximum of 0.57 g/batch for 1:10. Glycosidic-linkage composition showed that all extraction conditions allowed to obtain mainly arabinogalactans. When the unextracted insoluble material was re-extracted under the same conditions (MAE2), a further extraction of polysaccharides was observed (0.34 g/batch for 1:10), mainly galactomannans. Also, a high amount of oligosaccharides, mainly derived from galactomannans, can be obtained in MAE2 (0.96 g/batch for 1:10). This technology allows to obtain galactomannans and arabinogalactans in proportions that are dependent on the operating conditions.

  18. Wicking of liquid nitrogen into superheated porous structures

    Science.gov (United States)

    Grebenyuk, Yulia; Dreyer, Michael E.

    2016-09-01

    Evaporation in porous elements of liquid-vapor separation devices can affect the vapor-free cryogenic propellant delivery to spacecraft engines. On that account, the capillary transport of a cryogenic liquid subjected to evaporation needs to be understood and assessed. We investigate wicking of liquid nitrogen at saturation temperature into superheated porous media. A novel test facility was built to perform wicking experiments in a one-species system under non-isothermal conditions. A setup configuration enabled to define the sample superheat by its initial position in a stratified nitrogen vapor environment inside the cryostat. Simultaneous sample weight and temperature measurements indicated the wicking front velocity. The mass of the imbibed liquid nitrogen was determined varying the sample superheat, geometry and porous structure. To the author's extent of knowledge, these are the first wicking experiments performed with cryogenic fluids subjected to evaporation using the weight-time measurement technique. A one-dimensional macroscopic model describes the process theoretically. Results revealed that the liquid loss due to evaporation at high sample superheats leads to only a slight imbibition rate decrease. However, the imbibition rate can be greatly affected by the vapor flow created due to evaporation that counteracts the wicking front propagation.

  19. Electronic neutron personal dosimetry with superheated drop detectors

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F.; Apfel, R.E.; Curzio, G.; Nath, R

    2001-07-01

    The prototype of an electronic personal neutron dosemeter based on superheated drop detectors is presented. This battery operated device comprises a neutron sensor, bubble-counting electronics and a temperature controller ensuring an optimal dose equivalent response. The neutron sensor is a 12 ml detector vial containing an emulsion of about 50,000 halocarbon-12 droplets of 100 {mu}m diameter. The temperature controller is a low-power, solid-state device stabilising the emulsion at 31.5 deg. C by means of an etched foil heater. The microprocessor-controlled counting electronics relies on a double piezo-electric transducer configuration to record bubble formation acoustically via a comparative pulse-shape analysis of ambient noise and detector signals. The performance of the dosemeter was analysed in terms of the requirements presently developed for neutron personal dosemeters. The detection threshold is about 1 {mu}Sv, while the personal dose equivalent response to neutrons in the thermal to 62 MeV range falls within a factor 1.6 of 13 bubbles per {mu}Sv. (author)

  20. High-energy neutron dosimetry with superheated drop detectors

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F.; Agosteo, S.; Sannikov, A.V.; Silari, M

    2002-07-01

    A systematic analysis of the response of dichlorodifluoromethane superheated drop detectors was performed in the 46-133 MeV energy range. Experiments with quasi-monoenergetic neutron beams were performed at the Universite Catholique de Leuvain-la-Neuve, Belgium and the Svedberg Laboratory, Sweden, while tests in a broad field were performed at CERN. To determine the response of the detectors to the high-energy beams, the spectra of incident neutrons were folded over functions modelled after the cross sections for the production of heavy ions from the detector elements. The cross sections for fluorine and chlorine were produced in this work by means of the Monte Carlo high-energy transport code HADRON based on the cascade exciton model of nuclear interactions. The new response data permit the interpretation of measurements at high-energy accelerators and on high-altitude commercial flights, where a 30-50% under-response had been consistently recorded with respect to neutron dose equivalent. The introduction of a 1 cm lead shell around the detectors effectively compensates most of the response defect. (author)

  1. Active neutron spectrometry with superheated drop (bubble) detectors

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F.; Curzio, G. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari]|[Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Alberts, W.G.; Guldbakke, S.; Kluge, H.; Matzke, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    1995-12-31

    A new approach to neutron spectrometry has been developed in a joint project by DCMN Pisa and PTB Braunschweig. The system relies on the use of superheated drop (bubble) detectors and the thermodynamic control of their detection thresholds. This is the result of investigations into the physics of these detectors combined with extensive experimental work on their response to neutrons. These studies indicate that the higher the degree of superheat of a detector, the lower the minimum energy that secondary charged particles, and therefore primary neutrons, must impart to the droplets in order to nucleate their evaporation. Therefore, by controlling the temperature of the detectors, accurately defined detection thresholds, virtually any desired one, can be generated in the 0.01-10 MeV neutron energy range. An active prototype instrument has been developed: bubbles are counted acoustically and temperature regulation is achieved by means of thin heating strips. Tests with reference neutron spectra show that the system is suitable for few-channel spectrometry and may be useful for radiation protection dosimetry. Appropriate unfolding algorithms are currently investigated, to be ultimately implemented in an automatic device. (author).

  2. An object-oriented computational model for combined cycle cogeneration analysis; Um modelo computacional para analise de ciclos combinados para projetos de sistemas de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandre M. da; Balestieri, Jose A.P.; Magalhaes Filho, Paulo [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: amarcial@uol.com.br; perella@feg.unesp.br; pfilho@feg.unesp.br

    2000-07-01

    This paper presents the use of computational resources in a simulation procedure to predict the performance of combined cycle cogeneration systems in which energetic analysis is used in the modeling. Thermal demand of a consuming process are used as the main entrance data and, associated to the performance characteristics of each component of the system, it is evaluated the influence of some parameters of the system such as thermal efficiency and global efficiency. The computational language is Visual Basic for Applications associated to an electronic sheet. Two combined cycle cogeneration schemes are pre-defined: one is composed of a gas turbine, heat recovery steam generator and a back pressure steam turbine with one extraction, in which both are connected to the different pressure level process plant; the other scheme has a difference a two extraction-condensing steam turbine instead of the back pressure one. Some illustrative graphics are generated for allowing comparison of the appraised systems. The strategy of the system simulation is obtained by carefully linking the information of various components according to the flow diagrams. (author)

  3. Environmental Assessment for the Warren Station externally fired combined cycle demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    The proposed Penelec project is one of 5 projects for potential funding under the fifth solicitation under the Clean Coal Technology program. In Penelec, two existing boilers would be replaced at Warren Station, PA; the new unit would produce 73 MW(e) in a combined cycle mode (using both gas-fired and steam turbines). The project would fill the need for a full utility-size demonstration of externally fire combined cycle (EFCC) technology as the next step toward commercialization. This environmental assessment was prepared for compliance with NEPA; its purpose is to provide sufficient basis for determining whether to prepare an environmental impact statement or to issue a finding of no significant impact. It is divided into the sections: purpose and need for proposed action; alternatives; brief description of affected environment; environmental consequences, including discussion of commercial operation beyond the demonstration period.

  4. Mathematical Modeling of Ultra-Superheated Steam Gasification

    Science.gov (United States)

    Xin, Fen

    Pure steam gasification has been of interest in hydrogen production, but with the challenge of supplying heat for endothermic reactions. Traditional solutions included either combusting feedstocks at the price of decreasing carbon conversion ratio, or using costly heating apparatus. Therefore, a distributed gasifier with an Ultra-Superheated-Steam (USS) generator was invented, satisfying the heat requirement and avoiding carbon combustion in steam gasification. This project developed the first version of the Ultra-Superheated-Steam-Fluidization-Model (USSFM V1.0) for the USS gasifier. A stand-alone equilibrium combustion model was firstly developed to calculate the USS mixture, which was the input to the USSFM V1.0. Model development of the USSFM V1.0 included assumptions, governing equations, boundary conditions, supporting equations and iterative schemes of guessed values. There were three nested loops in the dense bed and one loop in the freeboard. The USSFM V1.0 included one main routine and twenty-four subroutines. The USSFM V1.0 was validated with experimental data from the Enercon USS gasifier. The calculated USS mixture had a trace of oxygen, validating the initial expectation of creating an oxygen-free environment in the gasifier. Simulations showed that the USS mixture could satisfy the gasification heat requirement without partial carbon combustion. The USSFM V1.0 had good predictions on the H2% in all tests, and on other variables at a level of the lower oxygen feed. Provided with higher oxygen feed, the USSFM V1.0 simulated hotter temperatures, higher CO% and lower CO2%. Errors were explained by assumptions of equilibrium combustion, adiabatic reactors, reaction kinetics, etc. By investigating specific modeling data, gas-particle convective heat transfers were found to be critical in energy balance equations of both emulsion gas and particles, while bubble size controlled both the mass and energy balance equations of bubble gas. Parametric study

  5. An experimental study of evaporation waves in a superheated liquid

    Science.gov (United States)

    Hill, Larry G.

    1990-01-01

    Evaporation waves in superheated liquids are studied using a rapid-depressurization facility consisting of a vertical glass test cell situated beneath a large, low-pressure reservoir. The objective of this study is to learn more about the physical mechanisms of explosive boiling (of which an evaporation wave is a specific example), as well as properties of the flow it produces.The test cell is initially sealed from the reservoir by a foil diaphragm, and is partially filled with a volatile liquid (Refrigerant 12 or 114). An experiment is initiated by rupturing the diaphragm via a pneumatically driven cutter. The instrumentation consists of fast-response pressure measurements, high-speed motion pictures, and spark-illuminated still photographs. The liquid temperature is typically 20°C; the liquid superheat is controlled by setting the reservoir pressure to values between vacuum and 1 atm. The pressures subsequent to depressurization are very much less than the critical pressure, and the initial temperatures are sufficiently low that, although the test liquid is highly superheated, the superheat limit is not approached. Evaporation waves in which bubble nucleation within the liquid column is suppressed entirely are considered almost exclusively.When the diaphragm is ruptured, the liquid pressure drops to virtually the reservoir value within a few milliseconds. Provided that the liquid superheat so obtained is sufficiently high, the free surface then erupts in a process known as explosive boiling, which is characterized by violent, fine-scale fragmentation of the superheated liquid and extremely rapid evaporation. The explosive boiling process proceeds as a "wavefront" into the liquid column, producing a highspeed, two-phase flow that travels upward into the low-pressure reservoir, emptying the test cell in a few hundred milliseconds. The speed of the wavefront varies between 0.2 and 0.6 m/s, depending on run conditions; the corresponding two-phase flow varies between

  6. Utilization of virtual reality for reading the superheated emulsion detector

    Energy Technology Data Exchange (ETDEWEB)

    Santos Sobrinho, Jose C.; Santo, Andre C.E.; Pereira, Claudio M.N.A.; Mol, Antonio C.A., E-mail: volksparati@hotmail.com, E-mail: cotelli.andre@gmail.com, E-mail: cmnap@ien.gov.br, E-mail: mol@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This paper presents a method based on Virtual Reality for reading the Superheated Emulsion Detector (Bubble Detector). The proposed method is an alternative to: automatic counters offered by the manufacturers of detectors, since they have a relatively high cost (acquisition, maintenance and periodic calibration), and visual counting of detectors, since it only has an advantage when there are a small number of bubbles. The method starts with the collection of detector's digital images in order to obtain a sequence of images to create an animation that is displayed with the help of Virtual Reality. To this end, it is modeled, using OpenGL graphics library, a virtual environment for visualizing and manipulating virtual detector. It is made, then a calibration of this virtual environment thus ensuring the correspondence of the model with reality. The reading of the detector (bubbles count) is made visually by the user with the assistance of stereo vision and a 3D cursor to navigation, marking and counting the bubbles. The user views a further auxiliary display that shows the three-dimensional cursor position, the labeled amount of bubbles and the measured dose. After testing, the following results were achieved: better precision in counting the bubbles compared with the 10% reported by the manufacturer of the automatic reader; achieving a low cost tool that requires no calibration constant in the process of maintenance and/or lifetime; minimizing the problem of manual counting for large number of bubbles and ease of use, because can be operated by a common user. (author)

  7. Rehabilitation and extension of the useful operating life of a high pressure casing of the 75 MW steam turbine of the thermoelectric power plant President Juarez in Rosarito, B.C.; Rehabilitacion y extension de vida util de una carcasa de alta presion de la turbina de vapor de 75 MW de la central termoelectrica Presidente Juarez en Rosarito, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Mazur C, Zdzislaw; Hernandez R, Alejandro; Luna R, Alberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Fernandez, Rafael; Nieblas, Enrique [Comision Federal de Electricidad, Rosarito, Baja California (Mexico)

    2004-07-01

    The effective operation of the steam turbines is important to the world industries, but as all machinery, it is necessary to constantly examine and give maintenance to this equipment with the purpose of producing better results. Yet, many steam turbines arrive at an operation period of 30 or 40 years, over their original design capacity. A factor like this, only augments the probabilities of future problems with the casings, such as: thermal fatigue fissures, deformation of the horizontal union and erosion problems in the low pressure housings. The deformation of the casing can affect its capacity to maintain aligned the stationary parts of the turbine, as a consequence, damages can appear in the fixed and rotary components by interference or friction. Also, the water induction can deform the casing to such a degree that, the alignment of the stationary parts is altered until it causes contact and friction between stationary and rotary parts. However, depending on the type and degree of the casing deformation, different methods of rehabilitation can be applied. The core goal is to recover the planarity of the union of the flanges, re-machining the plane of the flange of the upper and lower casing or, alternatively, to carry out a scraping by hand. [Spanish] El funcionamiento eficaz de las turbinas de vapor es importante para las industrias del mundo, pero como toda maquinaria, es necesario examinar y dar mantenimiento constantemente a este equipo con la finalidad de producir mejores resultados. Con todo, muchas turbinas de vapor llegan a un periodo de operacion de 30 o 40 anos, por encima de su capacidad de diseno original. Un factor como este, solo eleva las probabilidades de futuros problemas con las carcasas, tales como: fisuras por fatiga termica, deformacion de la union horizontal y problemas de erosion en las carcasas de baja presion. La deformacion de la carcasa puede afectar su capacidad para mantener alineadas las partes estacionarias de la turbina, como

  8. Flow investigations in the final stage of the low-pressure steam turbine of Schkopau power station - flow and moisture measurements carried out by the Institute of Turbo-Engines; Stroemungsuntersuchungen an der Endstufe der Niederdruckdampfturbine im Kraftwerk Schkopau - Stroemungs- und Naessemessungen des Instituts fuer Thermische Stroemungsmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Renner, M.; Seibold, A.; Stetter, H. [Stuttgart Univ. (Germany). Inst. fuer Thermische Stroemungsmaschinen und Maschinenlaboratorium; Cai, X.S. [University of Science and Technology, Shanghai, SH (China)

    1998-12-31

    Measurements of steam wetness are necessary for the determination of the thermodynamic state in a two-phase steam flow, which is for example the case of efficiency measurements in LP steam turbines. Since wetness measurements are always related to flow measurements, a combined pneumatic-optical probe for contemporary flow and wetness measurement has been developed at Institut fuer Thermische Stroemungsmaschinen of the University of Stuttgart (ITSM) in collaboration with an institute of the University of Shanghai Science and Technology (USST). The pneumatic part consists of a four-hole wedge probe. The optical part is based on multiwavelength-light extinction. During measurement in power plant Schkopau this measuring system has been introduced for the first time in a real steam turbine. The results of these flow and wetness measurements, that have been conducted both for nominal and partial load will be presented and discussed in this publication. Since institutes of RWTH Aachen and University of Hannover, even though with different type of probes, have also conducted measurements in the power plant in Schkopau, a comparison between the results obtained by the combined probe and these other ones can be made. (orig.) [Deutsch] Fuer die Bestimmung des thermodynamischen Zustandspunktes in einer Zweiphasen-Wasserdampfstroemung, wie es z.B. bei Wirkungsgradmessungen in der ND-Teilturbine von Kondensationsdampfturbinen notwendig ist, ist die Messung der Dampfnaesse erforderlich. Da Naessemessungen mit optischen Messverfahren immer auch mit Stroemungsmessungen verbunden sind, wurde am Institut fuer Thermische Stroemungsmaschinen der Universitaet Stuttgart (ITSM) in Zusammenarbeit mit einen Institut der University of Shanghai Science and Technology (USST) eine kombinierte optisch-pneumatische Sonde fuer gleichzeitige Stroemungs- und Naessemessungen in Zwei-Phasen Wasserdampfstroemungen entwickelt. Der pneumatische Teil der Sonde besteht aus einer 4-Loch Keilsonde. Das

  9. Wet Steam’ s Effect on the Pneumatic Torque of Mid-pressure Control Valve in AP1000 Nuclear Power Steam Turbine%湿蒸汽对AP1000核电汽轮机中调门气动力矩的影响

    Institute of Scientific and Technical Information of China (English)

    刘彦丰; 张旭瑞; 霍玉恒

    2015-01-01

    为了解核电汽轮机湿蒸汽对中压进汽蝶阀的气动力矩的影响,利用FLUENT中Mixture多相流模型对AP1000核电汽轮机中调门的气动力矩进行汽水两相流数值模拟,分别对中调门不同开度下湿蒸汽汽水两相流和蒸汽单相流气动力矩的模拟结果进行比较分析。结果表明:中调门开启过程中,气动力矩先逐渐增大,最大值发生于中调门40°开度时,中调门开度继续增大,气动力矩逐渐减小。湿蒸汽汽水两相流对中调门的气动力矩为蒸汽单相流的两倍之多,增加了阀门发生卡涩故障的风险。%To understand how wet steam in nuclear power steam turbine affects the pneumatic torque of medium⁃pressure butterfly valve, the mixture multiphase flow model in FLUNET was first used to make numerical simulation for wet steam’ s two phase flow. The simulation is about the pneumatic torque of mid⁃pressure control valve in AP1000 nuclear power steam turbine. And then the pneumatic torque’ s simulation results of wet steam’ s two⁃phase flow and single phase flow were compared under valve’ s different openings. The results show that the pneu⁃matic torque increases gradually until the maximum occurs in valve’ s 40 ° opening and that with the valve’ s open⁃ing getting bigger than 40° the pneumatic torque gradually decreases. The aerodynamic torque decreases when the valve’s opening continues to increase. The pneumatic torque of the wet steam’s two phase flow is more than double that of steam single⁃phase flow, thus increasing the risk of valve’ s jam fault.

  10. Nucleation efficiency of R134a as a sensitive liquid for superheated drop emulsion detector

    Indian Academy of Sciences (India)

    Mala Das; R Sarkar; P K Mondal; S Saha; B K Chatterjee; S C Roy

    2010-10-01

    Superheated emulsion detector is known to detect neutrons, γ-rays and other charged particles. The present work includes the study of nucleation efficiency of super-heated drops of one of the CFC-free liquids, R134a (C2H2F4), to fast neutrons, its response to -rays from 241Am and 137Cs and compare its nucleation efficiency with that of R12. The observation indicates that because of the presence of hydrogen, the nucleation efficiency is less in R134a than in R12 in the present neutron energy range of considera-tion. R134a is one of the most environment-friendly, commercially available liquid that is suitable for superheated drop detector, specially in neutron dosimetry and one needs to investigate it in detail.

  11. Characterization of R-134A superheated droplet detector for neutron detection

    CERN Document Server

    Mondal, Prasanna Kumar; Chatterjee, Barun Kumar

    2013-01-01

    R-134A (C2H2F4) is a low cost, easily available and chlorine free refrigerant, which in its superheated state can be used as an efficient neutron detector. Due to its high solubility in water the R-134A based superheated droplet detectors (SDD) are usually very unstable unless the detector is fabricated using a suitable additive, which stabilizes the detector. The SDD is known to have superheated droplets distributed in a short-lived and in a relatively longer-lived metastable state. We have studied the detector response to neutrons using a 241AmBe neutron source and obtained the temperature variation of the nucleation parameters and the interstate kinetics of these droplets using a two-state model.

  12. Casting structure of pure aluminum by electric pulse modification at different superheated temperatures

    Institute of Scientific and Technical Information of China (English)

    Jingang Qi; Jianzhong Wang; Xingjiang Liu; Bing Wang; Daqiang Cang

    2005-01-01

    Electric pulse modification (EPM) is a novel technique that reduces grain size by altering the structure of a melt. It was investigated that the response of the casting structure of high pure aluminum to EPM in different superheated melts. The results indicate that the grain refining effect of a given pulse electric field holds an optimal temperature range, moreover, a lower or higher superheated temperature will both disadvantage the improvements of casting structure. It essentially lies in the cooperative action between the distorted absorption of clusters and the activated capability of atoms in the aluminum melt.

  13. Static and dynamic superheated water extraction of essential oil components from Thymus vulgaris L.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Rado, Ewelina; Wianowska, Dorota

    2009-09-01

    Superheated water extraction (SWE) performed in both static and dynamic condition (S-SWE and D-SWE, respectively) was applied for the extraction of essential oil from Thymus vulgaris L. The influence of extraction pressure, temperature, time, and flow rate on the total yield of essential oil and the influence of extraction temperature on the extraction of some chosen components are discussed in the paper. The SWE extracts are related to PLE extracts with n-hexane and essential oil obtained by steam distillation. The superheated water extraction in dynamic condition seems to be a feasible option for the extraction of essential oil components from T. vulgaris L.

  14. PID Controller Parameters Tuning Based-on Satisfaction for Superheated Steam Temperature of Power Station Boiler

    Directory of Open Access Journals (Sweden)

    Benxian Xiao

    2014-06-01

    Full Text Available Proposed the PID controller parameters tuning method based-on New Luus-Jaakola (NLJ algorithm and satisfaction idea. According to the different requirements of each performance index, designed the satisfaction function with fuzzy constraint attributes, and then determined the comprehensive satisfaction function for PID tuning by NLJ algorithm. Provided the steps of PID controller parameters tuning based on the NLJ algorithm and satisfaction, and applied this tuning method to the cascade control system of superheated steam temperature for Power Station Boiler. Finally the simulation and experiment results have shown the proposed method has good dynamic and static control performances for this complicated superheated steam temperature control system.

  15. INDITEP: The first pre-commercial DSG solar power plant

    Energy Technology Data Exchange (ETDEWEB)

    Zarza, Eduardo; Rojas, M' a Esther; Gonzalez, Lourdes [Plataforma Solar de Almeria, CIEMAT, Apartado P.O. Box 22, 04200 Tabernas, Almeria (Spain); Caballero, Jose M' a [INITEC Energia, Principe de Vergara 120, 28002 Madrid (Spain); Rueda, Fernando [Iberdrola Ingenieria consultoria, Avda. de Burgos, 8B, Edif. Genesis, 28036 Madrid (Spain)

    2006-10-15

    This paper presents the conceptual design of the first solar power plant using Direct Steam Generation (DSG) in a parabolic-trough solar field. Experience and know-how in the DSG process acquired during the DISS project were applied in designing the solar field of this plant. The 5-MWe plant is composed of a DSG parabolic-trough solar field connected to a superheated steam Rankine power cycle. The solar field produces 410{sup o}C/70-bar superheated steam. Detail engineering of this plant is currently underway within the framework of the INDITEP project, which is promoted by a German-Spanish consortium with the financial support of the European Commission (Contract No. ENK5-CT-2001-00540). The main design objective is to assure high operational flexibility and reliability. This is the reason why a robust superheated steam turbine has been selected, though the efficiency of its power block is modest. (author)

  16. 76 FR 81528 - United States v. Exelon Corporation, et al.; Proposed Final Judgment and Competitive Impact...

    Science.gov (United States)

    2011-12-28

    ... turbine, wind turbine, steam turbine, combustion turbine, or combined cycle) to transform the energy in... efficient coal-fired steam turbine units--have relatively low operating costs. ``Peaking'' units--which... steam turbine units--have costs lower than those of peaking units but higher than those of...

  17. Thermochemical recuperative combined cycle with methane-steam reforming combustion; Tennengasu kaishitsu nensho ni yoru konbaindo saikuru hatsuden no kokoritsuka oyobi denryoku fuka heijunka taio

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, R.; Essaki, K.; Tsutsumi, A. [The University of Tokyo, Tokyo (Japan). Dept. of Chemical System Engineering; Kaganoi, S.; Kurimura, H. [Teikoku Sekiyu Co., Tokyo (Japan); Sasaki, T.; Ogawa, T. [Toshiba Co., Tokyo (Japan)

    2000-03-10

    Thermochemical recuperative combined cycles with methane-steam reforming are proposed for improving their thermal efficiency and for peak-load leveling. For targeting higher thermal efficiency, a cycle with methane-steam reforming reaction heated by gas turbine exhaust was analyzed. The inlet temperature of gas turbine was set at 1,350 degree C. Low-pressure steam extracted from a steam turbine is mixed with methane, and then this mixture is heated by part of the gas turbine exhaust to promote a reforming reaction. The rest of the exhaust heat is used to produce steam, which drives steam turbines to generate electricity. The effect of steam-to-methane ratio (S/C) on thermal efficiency of the cycle, as well as on methane conversion, is investigated by using the ASPEN Plus process simulator. The methane feed rate was fixed at constant and S/C ratio was varied from 2.25 to 4.75. Methane conversion shows an increasing trend toward the ratio and has a maximum value of 17.9 % at S/C=4.0. Thermal efficiency for the system is about 51 % higher than that calculated for a conventional 1,300 degree C class combined cycle under similar conditions. A thermochemical recuperative combined cycle is designed for peak-load leveling. In night-time operation from 20 : 00 to 8 : 00 it stores hydrogen produced by methane steam reforming at S/C=3.9 to save power generation. The gas turbine inlet temperature is 1,330 degree C. In daytime operation from 8 : 00 to 20 : 00 the chemically recuperated combined cycle operated at S/C=2.0 is driven by the mixture of a combined cycle operated at constant load with the same methane feed rate, whereas daytime operation generated power 1.26 times larger than that of the combined cycle. (author)

  18. Ultra Low Level Environmental Neutron Measurements Using Superheated Droplet Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, A.C. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Estrada Nacional 10 - km 139.7, 2695-066 Bobadela LRS (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa. Av. Prof. Gama Pinto, 2, 1649- 003 Lisboa (Portugal); Felizardo, M.; Girard, T.A.; Kling, A.; Ramos, A.R. [Centro de Fisica Nuclear, Universidade de Lisboa. Av. Prof. Gama Pinto, 2, 1649- 003 Lisboa (Portugal); Marques, J.G.; Prudencio, M.I.; Marques, R.; Carvalho, F.P. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Estrada Nacional 10 - km 139.7, 2695-066 Bobadela LRS (Portugal)

    2015-07-01

    Through the application of superheated droplet detectors (SDDs), the SIMPLE project for the direct search for dark matter (DM) reached the most restrictive limits on the spin-dependent sector to date. The experiment is based on the detection of recoils following WIMP-nuclei interaction, mimicking those from neutron scattering. The thermodynamic operation conditions yield the SDDs intrinsically insensitive to radiations with linear energy transfer below ∼150 keVμm{sup -1} such as photons, electrons, muons and neutrons with energies below ∼40 keV. Underground facilities are increasingly employed for measurements in a low-level radiation background (DM search, gamma-spectroscopy, intrinsic soft-error rate measurements, etc.), where the rock overburden shields against cosmic radiation. In this environment the SDDs are sensitive only to α-particles and neutrons naturally emitted from the surrounding materials. Recently developed signal analysis techniques allow discrimination between neutron and α-induced signals. SDDs are therefore a promising instrument for low-level neutron and α measurements, namely environmental neutron measurements and α-contamination assays. In this work neutron measurements performed in the challenging conditions of the latest SIMPLE experiment (1500 mwe depth with 50-75 cm water shield) are reported. The results are compared with those obtained by detailed Monte Carlo simulations of the neutron background induced by {sup 238}U and {sup 232}Th traces in the facility, shielding and detector materials. Calculations of the neutron energy distribution yield the following neutron fluence rates (in 10{sup -8} cm{sup -2}s{sup -1}): thermal (<0.5 eV): 2.5; epithermal (0.5 eV-100 keV): 2.2; fast (>1 MeV): 3.9. Signal rates were derived using standard cross sections and codes routinely employed in reactor dosimetry. The measured and calculated neutron count rates per unit of active mass were 0.15 ct/kgd and 0.33 ct/kg-d respectively. As the major

  19. Detection of the high vibration origin in the body of an electrical generator driven by steam turbine applying diagnostic techniques; Deteccion del origen de alta vibracion en el cuerpo de un generador electrico accionado por turbinas de vapor aplicando tecnicas de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Bravo, Fernando (Mexico)

    2007-11-15

    One of the problems that electric generators present is the high vibration due to causes that can go from simple mechanical unbalance, misalignment, mechanical relaxation, resonance or some other interaction that can influence in the system. In this document is presented the vibration analysis of an electric generator with a capacity of 350 MW, driven by a steam turbine composed of three stages (high pressure, intermediate pressure and low pressure) connected to the electric generator through a rigid connection. [Spanish] Uno de los problemas que se presentan en los generadores electricos es la alta vibracion debida a causas que pueden ir desde un simple desbalance mecanico, desalineamiento, aflojamiento mecanico, resonancia o alguna otra interaccion que pueda influir en el sistema. Se presenta en este documento el analisis de vibracion de un generador electrico con una capacidad de 350 MW, impulsado por una turbina de vapor compuesta de tres etapas (alta presion, presion intermedia y baja presion) acopladas al generador electrico a traves de un acoplamiento rigido.

  20. 汽轮机用钢2Cr11MoVNbN 的锻造工艺及锻后热处理工艺%Forging Process and Heat Treatment Process after Forging of 2Cr11MoVNbN Steel Used for Steam Turbine

    Institute of Scientific and Technical Information of China (English)

    赵森; 黄冬明

    2013-01-01

    2Cr11MoVNbN steel is one of the steel grades with best heat-resistant property among 12% Cr steels, and it is an ideal material used for subcritical and supercritical steam turbine blades .Through smelting with VOD meth-od, drawing with top flat anvil and bottom V type anvil , and upsetting with more than one heat and small percent reduc-tion, the 2Cr11MoVNbN steel blades has been produced successfully to meet technical requirements .%  2Cr11MoVNbN钢是目前12%Cr系耐热性能最好的钢种之一,是一种较为理想的亚临界、超临界汽轮机叶片用材料。通过采用 VOD炼钢,上平砧,下 V型砧拔长下料,多火次,小压下量镦粗工艺,成功锻出2Cr11MoVNbN叶片,质量达到要求。

  1. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Gas turbine performance

    DEFF Research Database (Denmark)

    Haglind, Fredrik

    2010-01-01

    -load performance. Subsequently, in another paper, the effects of variable geometry on the part-load performance for combined cycles used for ship propulsion will be presented. Moreover, this paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis......The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part...... of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part...

  2. A MATHEMATICAL MODEL OF THE ROASTING CHESTNUTS PROCESS BY SUPERHEATED STEAM

    Directory of Open Access Journals (Sweden)

    A. N. Ostrikov

    2013-01-01

    Full Text Available The mathematic modeling for chestnuts roasting process by superheated steam is conducted. Diffusion and thermal diffusion coefficients are used for process description. Initial conditions and boundary conditions of the third kind for thermal conductivity and mass transfer equations are set.

  3. Correlation Between Superheated Liquid Fragility And Onset Temperature Of Crystallization For Al-Based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Guo J.

    2015-06-01

    Full Text Available Amorphous alloys or metallic glasses have attracted significant interest in the materials science and engineering communities due to their unique physical, mechanical, and chemical properties. The viscous flow of amorphous alloys exhibiting high strain rate sensitivity and homogeneous deformation is considered to be an important characteristic in thermoplastic forming processes performed within the supercooled liquid region because it allows superplastic-like deformation behavior. Here, the correlation between the superheated liquid fragility, and the onset temperature of crystallization for Al-based alloys, is investigated. The activation energy for viscous flow of the liquid is also investigated. There is a negative correlation between the parameter of superheated liquid fragility and the onset temperature of crystallization in the same Al-based alloy system. The activation energy decreases as the onset temperature of crystallization increases. This indicates that the stability of a superheated liquid can affect the thermal stability of the amorphous alloy. It also means that a liquid with a large superheated liquid fragility, when rapidly solidified, forms an amorphous alloy with a low thermal stability.

  4. Inhibition of lipid oxidation in pork bundles processing by superheated steam frying.

    Science.gov (United States)

    Huang, Tzou-Chi; Ho, Chi-Tang; Fu, Hui-Yin

    2004-05-19

    The effect of superheated steam treatment on the oxidative stability of lipids in packaged Zousoon (pork bundles) was investigated. The aroma quality of Zousoon samples was evaluated by sensory analysis and chromatographic analysis of volatiles. Results of this study indicated that oxidation of lipids occurred in pan-fried Zousoon after prolonged storage. Significant amounts of highly volatile compounds such as formaldehyde, acetaldehyde, acetone, and hexanal in Zousoon were identified by a modified method of cysteamine derivatization followed by gas chromatography-mass spectrometry (GC-MS) analysis. Superheated steam was found to be effective in suppressing lipid oxidation in canned Zousoon as compared with Zousoon fried by the conventional method in a frying pan. The superheated steam-fried samples had relatively low thiobarbituric acid reactive substance (TBARS) and peroxide (POV) values before and after storage, whereas samples prepared by pan frying had relatively high TBARS and POV values before and after storage. Superheated steam-fried Zousoon had superior lipid stability to that prepared by the conventional pan-frying method.

  5. Effect of Melt Superheating Treatment on Directional Solidification Interface Morphology of Multi-component Alloy

    Institute of Scientific and Technical Information of China (English)

    Changshuai Wang; Jun Zhang; Lin Liu; Hengzhi Fu

    2011-01-01

    The influence of melt superheating treatment on the solid/liquid (S/L) interface morphology of directionally solidified Ni-based superalloy DZ125 is investigated to elucidate the relationship between melt characteristic and S/L interface stability. The results indicate that the interface morphology is not only related to the withdrawal velocity (R) but also to the melt superheating temperature (Ts) when the thermal gradient of solidification interface remains constant for different Ts with appropriate superheating treatment regulation. The interface morphology changes from cell to plane at R of 1.1 μm/s when Ts increases from 1500°C to 1650°C, and maintains plane with further elevated Ts of 1750°C. However, the interface morphology changes from coarse dendrite to cell and then to cellular dendrite at R of 2.25 μm/s when Ts increases from 1500°C to 1650°C and then to 1750°C. It is proved that the solidification onset temperature and the solidification interval undergo the nonlinear variation when Ts increases from 1500°C to 1680°C, and the turning point is 1650°C at which the solidification onset temperature and the solidification interval are all minimum. This indicates that the melt superheating treatment enhances the solidification interface stability and has important effect on the solidification characteristics.

  6. Microwave super-heated boiling of organic liquids: Origin, effect and application

    NARCIS (Netherlands)

    Chemat, F.; Esveld, E.

    2001-01-01

    This paper reports the state of the art of the microwave super-heated boiling phenomenon. When a liquid is heated by microwaves, the temperature increases rapidly to reach a steady temperature while refluxing. It happens that this steady state temperature can be up to 40 K higher than the boiling po

  7. Mechanistic Model for Atomization of Superheated Liquid Jet Fuel Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As air-breathing combustion applications advance, increased use of fuel for cooling, combined with cycle advancements, leads to a situation where the fuel can...

  8. Mechanistic Model for Atomization of Superheated Liquid Jet Fuel Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As air-breathing combustion applications advance, increased use of fuel for cooling, combined with cycle advancements, leads to a situation where the fuel can become...

  9. The Reaction of Carbonates in Contact with Superheated Silicate Melts: New Insights from MEMIN Laser Melting Experiments

    Science.gov (United States)

    Hamann, C.; Hecht, L.; Schäffer, S.; Deutsch, A.; Lexow, B.

    2016-08-01

    The reaction of carbonates in contact with silicate impact melts is discussed quite controversially in the impact community. Here, we discuss four MEMIN laser melting experiments involving carbonates in contact with superheated silicate melts.

  10. 首台300MW汽轮机循环水供热改造技术与经济指标分析%Transformation Technology and Economic Indicators Analysis of the First 300MW Steam Turbine Supplying Heat Using High-temperature Circulating Water

    Institute of Scientific and Technical Information of China (English)

    成渫畏; 王学栋; 宋昂

    2016-01-01

    This paper introduces the technology and content of the first subcritical 300MW steam turbine transforma-tion using high-temperature circulating water for direct heating, and illustrates the similarities and differences with the 135MW stage units. On the basis of transformation technology of double back-pressure and dual rotor switch on 135MW stage units, Technical problems that commonality transformation of dual low-pressure cylinder, feeding water pump turbine transformation, and condensate polishing treatment system transformation have been solved on 300MW turbine unit to achieve direct heating using high-temperature circulating water. After transformation, the performance test results show that economic indicators of the unit have reached design values. Its energy-saving effect is remarkable.%介绍了首台亚临界300MW汽轮机高温循环水供热改造技术和改造内容,并阐述了与135MW等级机组改造的异同点。在135MW等级机组双背压双转子互换改造技术的基础上,300MW汽轮机解决了双层低压缸通用性改造、给水泵小汽轮机改造以及凝结水精处理系统改造等关键技术难题,成功实施了高温循环水直接供热技术改造。由改造后性能考核试验结果得知,机组各项经济指标达到设计值,节能效果显著。

  11. Modeling of an once through helical coil steam generator of a superheated cycle for sizing analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Sik; Sim, Yoon Sub; Kim, Eui Kwang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    A thermal sizing code, named as HSGSA (Helical coil Steam Generator Sizing Analyzer), for a sodium heated helical coil steam generator is developed for KALIMER (Korea Advanced LIquid MEtal Reactor) design. The theoretical modeling of the shell and tube sides is described and relevant correlations are presented. For assessment of HSGSA, a reference plant design case is compared to the calculational outputs from HSGSA simulation. 9 refs., 6 figs. (Author)

  12. Nonlinear dynamics of a vapor bubble expanding in a superheated region of finite size

    Science.gov (United States)

    Annenkova, E. A.; Kreider, W.; Sapozhnikov, O. A.

    2015-10-01

    Growth of a vapor bubble in a superheated liquid is studied theoretically. Contrary to the typical situation of boiling, when bubbles grow in a uniformly heated liquid, here the superheated region is considered in the form of a millimeter-sized spherical hot spot. An initial micron-sized bubble is positioned at the hot spot center and a theoretical model is developed that is capable of studying bubble growth caused by vapor pressure inside the bubble and corresponding hydrodynamic and thermal processes in the surrounding liquid. Such a situation is relevant to the dynamics of vapor cavities that are created in soft biological tissue in the focal region of a high-intensity focused ultrasound beam with a shocked pressure waveform. Such beams are used in the recently proposed treatment called boiling histotripsy. Knowing the typical behavior of vapor cavities during boiling histotripsy could help to optimize the therapeutic procedure.

  13. Nonlinear dynamics of a vapor bubble expanding in a superheated region of finite size

    Energy Technology Data Exchange (ETDEWEB)

    Annenkova, E. A., E-mail: a-a-annenkova@yandex.ru [Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Kreider, W. [Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th St., Seattle, WA 98105 (United States); Sapozhnikov, O. A. [Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th St., Seattle, WA 98105 (United States)

    2015-10-28

    Growth of a vapor bubble in a superheated liquid is studied theoretically. Contrary to the typical situation of boiling, when bubbles grow in a uniformly heated liquid, here the superheated region is considered in the form of a millimeter-sized spherical hot spot. An initial micron-sized bubble is positioned at the hot spot center and a theoretical model is developed that is capable of studying bubble growth caused by vapor pressure inside the bubble and corresponding hydrodynamic and thermal processes in the surrounding liquid. Such a situation is relevant to the dynamics of vapor cavities that are created in soft biological tissue in the focal region of a high-intensity focused ultrasound beam with a shocked pressure waveform. Such beams are used in the recently proposed treatment called boiling histotripsy. Knowing the typical behavior of vapor cavities during boiling histotripsy could help to optimize the therapeutic procedure.

  14. Superheating and melting behaviors of Ag clusters with Ni coating studied by molecular dynamics and experiments

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using molecular dynamics with embedded-atom-type interatomicpotentials, we simulated the melting behavior of a spherical Ag3055 cluster coated with Ni. The semi-coherent Ag/Ni interface formed at low temperatures acts as an effective barrier against the surface melting and leads to a substantial superheating of the Ag cluster. The melting point was found to be about 100 K above the equilibrium melting point of the bulk Ag crystal (1230 K±15 K) and about 290 K above that (1040 K) of the free Ag3055 cluster. A superheating of 70 K was observed in the high-temperature differential scanning calorimetry measurement for Ag particles with a mean size of 30 nm embedded in Ni matrix prepared by means of melt-spinning. Melting is initiated locally at the defective interfacial area and then propagates inwards, suggesting a heterogeneously nucleated melting event at the Ag/Ni interface.

  15. Specific heat of superheated Al-10Sr alloy melts[Foundation item

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The specific heat of superheated Al-10Sr melts was determined at different heating rates between 1  K/min and 20  K/min using a differential scanning calorimeter(DSC). As a whole, the specific heat increases with increasing temperature. A hump is observed on the specific heat curve at the temperature corresponding to the phase boundary temperature dependent on heating rate. Moreover, the hump shifts to higher temperature in the measured temperature range from about 840  ℃ to 890  ℃ with increasing heating rate. At certain temperature in the higher superheated zone, the specific heat of the melt as a function of temperature shows a sharp rise . The result indicates that disorder zone fraction begins to increase while atom clusters fraction decreases at the breaking temperature.

  16. Status of Superheated Spray and Post Combustor Particulate Modeling for NCC

    Science.gov (United States)

    Liu, Nan-Suey; Raju, Suri; Wey, Thomas

    2007-01-01

    At supersonic cruise conditions, high fuel temperatures, coupled with low pressures in the combustor, create potential for superheated fuel injection leading to shorter fuel jet break-up time and reduced spray penetration. Another issue particularly important to the supersonic cruise is the aircraft emissions contributing to the climate change in the atmosphere. Needless to say, aircraft emissions in general also contribute to the air pollution in the neighborhood of airports. The objectives of the present efforts are to establish baseline for prediction methods and experimental data for (a) liquid fuel atomization and vaporization at superheated conditions and (b) particle sampling systems and laboratory or engine testing environments, as well as to document current capabilities and identify gaps for future research.

  17. Generalized computer algorithms for enthalpy, entropy and specific heat of superheated vapors

    Science.gov (United States)

    Cowden, Michael W.; Scaringe, Robert P.; Gebre-Amlak, Yonas D.

    This paper presents an innovative technique for the development of enthalpy, entropy, and specific heat correlations in the superheated vapor region. The method results in a prediction error of less than 5 percent and requires the storage of 39 constants for each fluid. These correlations are obtained by using the Beattie-Bridgeman equation of state and a least-squares regression for the coefficients involved.

  18. A new method for neutron depth dosimetry with the superheated drop detector

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F.; Apfel, R.E. (Yale Univ., New Haven, CT (USA))

    1990-01-01

    Chemical composition and energy response of the Superheated Drop Detector (SDD) suggested to us a new technique for the direct measurement of dose equivalent depth distributions in tissue-equivalent phantoms, independently of impinging neutron spectra and energy degradation with depth. The SDD performance has been tested against the depth-dose curves published in NCRP Report 38. The experimental results, in agreement with the expected values, confirm the applicability of this method. (author).

  19. Detection of bubble nucleation event in superheated drop detector by the pressure sensor

    Indian Academy of Sciences (India)

    MALA DAS; NILANJAN BISWAS

    2017-01-01

    Superheated drop detector consisting of drops of superheated liquid suspended in polymer or gel matrix is of great demand, mainly because of its insensitivity to β-particles and γ -rays and also because of the low cost. The bubble nucleation event is detected by measuring the acoustic shock wave released duringthe nucleation process. The present work demonstrates the detection of bubble nucleation events by using the pressure sensor. The associated circuits for the measurement are described in this article. The detection of events is verified by measuring the events with the acoustic sensor. The measurement was done using drops of various sizes to study the effect of the size of the drop on the pressure recovery time. Probability of detection of events has increased for larger size of the superheated drops and lesser volume of air in contact with the gel matrix. The exponential decay fitting to the pressure sensor signals shows the dead time for pressure recovery of such a drop detector to be a few microseconds.

  20. Superheating Suppresses Structural Disorder in Layered BiI3 Semiconductors Grown by the Bridgman Method

    Energy Technology Data Exchange (ETDEWEB)

    Johns, Paul M.; Sulekar, Soumitra; Yeo, Shinyoung; Baciak, James E.; Bliss, Mary; Nino, Juan C.

    2016-01-01

    The susceptibility of layered structures to stacking faults is a problem in some of the more attractive semiconductor materials for ambient-temperature radiation detectors. In the work presented here, Bridgman-grown BiI3 layered single crystals are investigated to understand and eliminate this structural disorder, which reduces radiation detector performance. The use of superheating gradients has been shown to improve crystal quality in non-layered semiconductor crystals; thus the technique was here explored to improve the growth of BiI3. When investigating the homogeneity of non-superheated crystals, highly geometric void defects were found to populate the bulk of the crystals. Applying a superheating gradient to the melt prior to crystal growth improved structural quality and decreased defect density from the order of 4600 voids per cm3 to 300 voids per cm3. Corresponding moderate improvements to electronic properties also resulted from the superheat gradient method of crystal growth. Comparative measurements through infrared microscopy, etch-pit density, x-ray rocking curves, and sheet resistivity readings show that superheat gradients in BiI3 growth led to higher quality crystals.

  1. Superheating suppresses structural disorder in layered BiI3 semiconductors grown by the Bridgman method

    Science.gov (United States)

    Johns, Paul M.; Sulekar, Soumitra; Yeo, Shinyoung; Baciak, J. E.; Bliss, Mary; Nino, Juan C.

    2016-01-01

    The susceptibility of layered structures to stacking faults is a problem in some of the more attractive semiconductor materials for ambient-temperature radiation detectors. In this work, Bridgman-grown BiI3 layered single crystals are investigated to understand and eliminate structural disorder, which reduces radiation detector performance. The use of superheating gradients has been shown by others to improve crystal quality in non-layered semiconductor crystals (Rudolph et al., 1996) [26]; thus the technique was explored to improve the growth of BiI3. When investigating the homogeneity of non-superheated crystals, highly geometric void defects were found to populate the bulk of the crystals. Applying a superheating gradient to the melt prior to crystal growth improved structural quality and decreased defect density from the order of 4600 voids per cm3 to 300 voids per cm3. Corresponding moderate improvements to electronic properties also resulted from the superheat gradient method of crystal growth. Comparative measurements through infrared microscopy, etch-pit density, X-ray rocking curves, and sheet resistivity readings show that superheat gradients in BiI3 growth led to higher quality crystals.

  2. Detection of bubble nucleation event in superheated drop detector by the pressure sensor

    Science.gov (United States)

    Das, Mala; Biswas, Nilanjan

    2017-01-01

    Superheated drop detector consisting of drops of superheated liquid suspended in polymer or gel matrix is of great demand, mainly because of its insensitivity to ß-particles and ?-rays and also because of the low cost. The bubble nucleation event is detected by measuring the acoustic shock wave released during the nucleation process. The present work demonstrates the detection of bubble nucleation events by using the pressure sensor. The associated circuits for the measurement are described in this article. The detection of events is verified by measuring the events with the acoustic sensor. The measurement was done using drops of various sizes to study the effect of the size of the drop on the pressure recovery time. Probability of detection of events has increased for larger size of the superheated drops and lesser volume of air in contact with the gel matrix. The exponential decay fitting to the pressure sensor signals shows the dead time for pressure recovery of such a drop detector to be a few microseconds.

  3. Integration of a thermal stresses supervisory system and useful life of steam turbine rotors; Integracion de un sistema supervisorio de esfuerzos termicos y vida util de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero, Antonio; Serrano, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Nebradt, G. Jesus; Leyva, M. Luis [Comision Federal de Electricidad, Mexico, D.F. (Mexico)

    2007-11-15

    The turbine wheels undergo high thermal and mechanical stresses caused by the requirements of their operation. This causes a mechanical damage (fatigue) that is accumulated according to the frequency whereupon the different operation ways (cold starts, lukewarm or hot) happen. On the other hand, the greater efficiency of power stations of combined cycle with respect to conventional power stations is reflected in a greater production cost of the electrical energy, which has forced to that conventional generation units designed to operate on base load, now are used as variable load units to satisfy the demand during the peak hours. The former, rebounds in a greater frequency of operations of shut downs and hot starts of turbines, reason why the fatigue damage will be increased when changing its operating range. In Mexico turbines there are turbines that have been 15 or 20 years in operation and that do not have a thermal stresses supervisor, reason why when changing their load operation from base load to variable load it is essential to install a rotor supervisor of thermal efforts, with the purpose of limiting or reducing the thermal stresses and in this way reduce the fatigue damage to extend their useful life. The article deals over the integration of a supervisory system of thermal stresses, that from the operation parameters of the turbine, determines the temperature gradient in the labyrinth seals zone between the control passage and the first passage of the high pressure section of the rotor, the thermal and mechanical stresses and the fatigue are calculated, determining the consumption of the useful life for each operation cycle (shutdown and starting). [Spanish] Los rotores de turbina experimentan altas esfuerzos termicos y mecanicos causados por los requerimientos de su operacion. Esto causa un dano mecanico (fatiga) que se acumula de acuerdo a la frecuencia con que los diferentes modos de operacion (arranques en frio, tibio o caliente) suceden. Por otro

  4. A Novel Strategy for Simulating the Main Fractionator of Delayed Cokers by Separating the De-superheating Process

    Institute of Scientific and Technical Information of China (English)

    LEI Yang; ZHANG Bingjian; HOU Xiaoqiong; CHEN Qinglin

    2013-01-01

    Delayed coking is an important process in refinery to convert heavy residue oils from crude distillation units (CDUs) and fluid catalytic cracking units (FCCUs) into dry gas,liquefied petroleum gas (LPG),gasoline,diesel,gas oils and cokes.The main fractionator,separating superheating reaction vapors from the coke drums into lighter oil products,involves a de-superheating section and a rectifying section,and couldn't be simulated as a whole column directly because of non-equilibrium in the de-superheating section.It is very important to correctly simulate the main fractionator for operational parameter and energy-use optimization of delayed cokers.This paper discusses the principle of de-superheating processes,and then proposes a new simulation strategy.Some key issues such as composition prediction of the reaction vapors,selection of thermodynamic methods,estimation of tray efficiency,etc.are discussed.The proposed simulation approach is applied to two industrial delayed cokers with typical technological processes in a Chinese refinery by using PRO/II.The simulation results obtained are well consistent with the actual operation data,which indicates that the presented approach is suitable to simulate the main fractionators of delayed cokers or other distillation columns consisting of de-superheating sections and rectifying sections.

  5. Theorical and experimental study of the induced forces by the mixed, divergent, convergent and straight labyrinth of seal systems on the steam turbines, gas turbines and compressor rotors; Estudio teorico-experimental de las fuerzas inducidas por los sistemas de sellos de laberinto rectos, convergentes, divergentes y mixtos sobre los rotores de turbinas de vapor, turbinas de gas y compresores

    Energy Technology Data Exchange (ETDEWEB)

    Salazar San Andres, Octavio Ramon

    1991-12-31

    A theoretical and experimental research is conducted in order to determine the labyrinth seal forces, as well as the stiffness and damping coefficients for straight, convergent, divergent, and combined shapes on turbine and compressor rotors. The mathematical model is deduced on the basis of the single volume method and its solution is obtained by the perturbation procedure. The validation is achieved with published results. Experimental work carried out on a test bench is described in the text. This involved labyrinth seals with straight, convergent, and divergent profiles, as the published information relating to mixed type is sufficient to perform the evaluation. The conclusions demonstrate that the model is able to predict and determine the performance of labyrinth seals based on forces and rotordynamic coefficients for static and dynamic motions. Finally, tests on real steam turbines of 300 MW are recommended. In this case the high pressures and use of wheels with strips on the periphery and supported by the upper part of blades, increase the susceptibility of self excited subsynchronous vibrations. [Espanol] Se presenta una investigacion teorica-experimental relacionada con la obtencion y validacion de un modelo matematico capaz de predecir las fuerzas y los coeficientes de rigidez y amortiguamiento de los sellos de laberinto de tipo recto, convergente, divergente y mixto que se emplean en turbinas y compresores tanto terrestres como aereos. El modelo matematico propuesto se deduce a partir del metodo de un solo volumen y su solucion se obtiene a traves de metodos perturbatorios. La validacion del mismo se consigue al comparar con resultados experimentales publicados en revistas especializadas y con los datos medidos en un banco de pruebas cuya descripcion se incluye en el trabajo, cualculado para sellos rectos, convergentes y divergentes, ya que la informacion publicada respecto al tipo mixto o combinado es suficiente. Las conclusiones de la investigacion

  6. Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

    Science.gov (United States)

    Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

    2016-02-01

    A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

  7. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    Energy Technology Data Exchange (ETDEWEB)

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  8. Improvement of the phase transition homogeneity of superheated superconducting tin granules

    CERN Document Server

    Calatroni, Sergio; Czapek, G; Ebert, T R; Hasenbalg, F; Hauser, M G; Janos, S; Kainer, K U; Knoop, K M; Moser, U; Palmieri, V G; Pretzl, Klaus P; Sahli, B; Sgobba, Stefano; Vollenberg, W; Wyss, C

    2000-01-01

    A considerably improved phase transition homogeneity was observed with superheated superconducting Sn spheres as a result of laser melting and fast cooling. These spheres exhibited a very homogeneous phase transition behaviour independent of the orientation of the spheres with respect to the direction of the external magnetic field. Compared to previously untreated Sn spheres the spread of the phase transition boundaries was reduced by almost an order of magnitude. In addition, we studied mass production of Sn structures using vacuum evaporation and deposition. First encouraging results are reported. (7 refs).

  9. Heat Transfer of Condensation in Smooth Round Tube from Superheated Vapor

    OpenAIRE

    Xiao, Jiange; Hrnjak, Pega

    2016-01-01

    Heat transfer of R134a condensing in a horizontal smooth round tube with 6.1 mm inner diameter is invested in this study. Experimental results on the heat transfer coefficient (HTC) with mass flux from 50 to 200 kg m-2 s-1 and heat flux from 5 to 15 kW m-2 are provided. Heat transfer behavior is compared between condensing superheated (CSH) region and two-phase (TP) region. Experimental result shows that in TP region, higher mass flux results in higher HTC while heat flux does not affect HTC....

  10. Superheating and Homogeneous Single Bubble Nucleation in a Solid-State Nanopore

    Science.gov (United States)

    Nagashima, Gaku; Levine, Edlyn V.; Hoogerheide, David P.; Burns, Michael M.; Golovchenko, Jene A.

    2014-01-01

    We demonstrate extreme superheating and single bubble nucleation in an electrolyte solution within a nanopore in a thin silicon nitride membrane. The high temperatures are achieved by Joule heating from a highly focused ionic current induced to flow through the pore by modest voltage biases. Conductance, nucleation, and bubble evolution are monitored electronically and optically. Temperatures near the thermodynamic limit of superheat are achieved just before bubble nucleation with the system at atmospheric pressure. Bubble nucleation is homogeneous and highly reproducible. This nanopore approach more generally suggests broad application to the excitation, detection, and characterization of highly metastable states of matter. PMID:25062192

  11. First Dark Matter Limits from a Large-Mass, Low-Background Superheated Droplet Detector

    CERN Document Server

    Collar, J.I.; Girard, T.A.; Limagne, D.; Miley, H.S.; Waysand, G.

    2000-01-01

    We report on the fabrication aspects and calibration of the first large active mass ($\\sim15$ g) modules of SIMPLE, a search for particle dark matter using Superheated Droplet Detectors (SDDs). While still limited by the statistical uncertainty of the small data sample on hand, the first weeks of operation in the new underground laboratory of Rustrel-Pays d'Apt already provide a sensitivity to axially-coupled Weakly Interacting Massive Particles (WIMPs) competitive with leading experiments, confirming SDDs as a convenient, low-cost alternative for WIMP detection.

  12. Machine Learning Method Applied in Readout System of Superheated Droplet Detector

    Science.gov (United States)

    Liu, Yi; Sullivan, Clair Julia; d'Errico, Francesco

    2017-07-01

    Direct readability is one advantage of superheated droplet detectors in neutron dosimetry. Utilizing such a distinct characteristic, an imaging readout system analyzes image of the detector for neutron dose readout. To improve the accuracy and precision of algorithms in the imaging readout system, machine learning algorithms were developed. Deep learning neural network and support vector machine algorithms are applied and compared with generally used Hough transform and curvature analysis methods. The machine learning methods showed a much higher accuracy and better precision in recognizing circular gas bubbles.

  13. Improvement of the phase transition homogeneity of superheated superconducting tin granules

    Energy Technology Data Exchange (ETDEWEB)

    Calatroni, S.; Casalbuoni, S. E-mail: sara@lhc.lhep.unibe.ch; Czapek, G.; Ebert, T.; Hasenbalg, F.; Hauser, M.; Janos, S.; Kainer, K.U.; Knoop, K.M.; Moser, U.; Palmieri, V.G.; Pretzl, K.; Sahli, B.; Sgobba, S.; Vollenberg, W.; Wyss, Ch.P

    2000-04-07

    A considerably improved phase transition homogeneity was observed with superheated superconducting Sn spheres as a result of laser melting and fast cooling. These spheres exhibited a very homogeneous phase transition behaviour independent of the orientation of the spheres with respect to the direction of the external magnetic field. Compared to previously untreated Sn spheres the spread of the phase transition boundaries was reduced by almost an order of magnitude. In addition, we studied mass production of Sn structures using vacuum evaporation and deposition. First encouraging results are reported.

  14. Extraction of amino acids from soils and sediments with superheated water

    Science.gov (United States)

    Cheng, C. N.; Ponnamperuma, C.

    1974-01-01

    A method of extraction for amino acids from soils and sediments involving superheated water has been investigated. About 75-97 per cent of the amino acids contained in four soils of a soil profile from Illinois were extracted by this method. Deep penetration of water into soil aggregates and partial hydrolysis of peptide bonds during this extraction by water at high temperature are likely mechanisms responsible for the release of amino acids from samples. This extraction method does not require subsequent desalting treatments when analyses are carried out with an ion-exchange amino acid analyzer.

  15. A position-sensitive neutron spectrometer/dosimeter based on pressurized superheated drop (bubble) detectors

    Science.gov (United States)

    d'Errico, F.; Nath, R.; Holland, S. K.; Lamba, M.; Patz, S.; Rivard, M. J.

    2002-01-01

    A position-sensitive, superheated emulsion chamber (SEC) is introduced for three-dimensional (3D) spectrometry and dosimetry of fast neutrons. The detector is based on a fine suspension of octafluorocyclobutane droplets emulsified in a tissue-equivalent gel. This gel is highly viscous and immobilizes the bubbles at the location of their formation. At an operating temperature of 35°C, the droplets are moderately superheated and their evaporation is nucleated by the densely ionizing products of fast neutron interactions, with no response to sparsely ionizing radiations. Thus, when a neutron emitter such as a 252Cf brachytherapy source is inserted in the SEC, a bubble distribution forms around the source and makes the neutron field visible. The SEC is operated at different externally applied pressures that correspond to different response thresholds. These responses form a virtually orthogonal matrix which is suitable for spectrometry and allows the use of effective few channel unfolding procedures, yielding the spatial dependence of absorbed dose and neutron energy spectra in-tissue. Bubble spatial distributions in the chamber can be determined through optical tomography or magnetic resonance imaging (MRI). A 3D, steady-state MRI method has proven particularly effective for this purpose. After the imaging, the SEC can be pressurized above the halocarbon vapor tension in order to recondense the bubbles to the liquid phase. Within a few minutes, the device is annealed and ready to be used again for repeated measurements improving the bubble counting statistics.

  16. Sub-micrometer dropwise condensation under superheated and rarefied vapor condition.

    Science.gov (United States)

    Anand, Sushant; Son, Sang Young

    2010-11-16

    Phase change accompanying conversion of a saturated or superheated vapor in the presence of subcooled surfaces is one of the most common occurring phenomena in nature. The mode of phase change that follows such a transformation is dependent upon surface properties such as contact angle and thermodynamic conditions of the system. In present studies, an experimental approach is used to study the physics behind droplet growth on a partially wet surface. Superheated vapor at low pressures of 4-5 Torr was condensed on subcooled silicon surface with a static contact angle of 60° in the absence of noncondensable gases, and the condensation process was monitored using environmental scanning electron microscopy (ESEM) with sub-microscopic spatial resolution. The condensation process was analyzed in the form of size growth of isolated droplets before a coalescence event ended the regime of single droplet growth. Droplet growth obtained as a function of time reveals that the rate of growth decreases as the droplet increases in size. This behavior is indicative of an overall droplet growth law existing over larger time scales for which the current observations in their brief time intervals could be fitted. A theoretical model based on kinetic theory further support the experimental observations indicating a mechanism where growth occurs by interfacial mass transport directly on condensing droplet surface. Evidence was also found that establishes the presence of sub-microscopic droplets nucleating and growing between microscopic droplets for the partially wetting case.

  17. Laminar film condensation from downward flowing superheated vapors onto a non-isothermal sphere

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.H. [Dept. of Mold and Die Engineering, National Kaohsiung Univ. of Applied Sciences, Kaohsiung (Taiwan)

    2001-11-01

    A model is developed for the study of mixed convection film condensation from downward flowing superheated vapors onto a sphere with variable wall temperature. The model combined natural convection dominated and forced convection dominated film condensation, including effects of superheated vapor, pressure gradient and wall temperature variation can be solved numerically by the fourth-order Runge-Kutta technique. By the present numerical approach, the mean heat transfer is evaluated up to the critical angle of the condensate layer, {phi}{sub c}. In general, the result of mean heat transfer shows that, as A, the wall-temperature amplitude, increases, the value of NuRe{sup -1/2} with inclusion of P, the pressure gradient effect, goes down slightly, however, the value of NuRe{sup -1/2} with the pressure gradient effect ignored will remain almost uniform. Further, for P=2.0, the mean heat transfer coefficient increases significantly, by 8.6-23.9%, depending on A, as the superheat parameter, Sp, increases within a practical range. (orig.)

  18. Effect of Superheated Steam Treatment on Changes in Moisture Content and Colour Properties of Coconut Slices

    Directory of Open Access Journals (Sweden)

    Mah Sook Yun

    2015-03-01

    Full Text Available Drying is one of the methods to preserve the quality and prolong the shelf life of food. Coconut meat was sliced and dried using superheated steam oven at 140°C, 160°C and 180°C. Drying was carried out at different drying time (5, 10, 15, 20, 25 and 30 minutes. The effect of drying temperature and time on the moisture content and colour properties (L, a, b and BI of the coconut slices were studied. The temperature and time significantly (p < 0.05 affected the moisture loss and colour values of coconut slices during superheated steam drying. The moisture content decreased with increased drying temperature and time. The values of L decreased with drying temperature and time. The a and b value of coconut slice dried at 140°C decreased initially then increased with time. Coconut slices dried at 160°C had their a values increased up to 20 minutes then decreased and b values increased up to 20 minutes then fluctuated. The a and b values of coconut slices dried at 180°C showed fluctuation. BI values of coconut slices increased with increasing drying time and temperature.

  19. Effect of Superheated Steam Roasting on Radical Scavenging Activity and Phenolic Content of Robusta Coffee Beans

    Directory of Open Access Journals (Sweden)

    Ooi Ee Shan

    2015-04-01

    Full Text Available Robusta coffee is one of the coffee species grown in Malaysia. However, there is little research conducted on Robusta coffee beans as Arabica coffee is more popular among the consumers. Coffee is a rich source of antioxidants, therefore research on antioxidant properties of Robusta coffee beans is important to explore its market value. Nowadays, most of coffee analysis is on conventional roasted coffee which reduces their antioxidant properties. In this study, Robusta coffee beans (Coffea canephora were subjected to superheated steam roasting at 200, 220 and 240 ˚C for 20-40 min to obtain light, medium and dark roast. The effect of different roasting temperature and time on the total phenolic content (TPC and radical scavenging activity (RSA of Robusta coffee bean was investigated. Total phenolic content of coffee brews decreased with the increase of roasting degree due to the degradation of phenolic compounds. The highest phenolic content was found at 220 ˚C for 20 min. Meanwhile, brews extracted from light roasted coffee and medium roasted at 220 ˚C for 20 min showed a maximum scavenging activity than those from green coffee. Brews from dark roasted coffee showed lowest radical scavenging activity and total phenol content. Hence, based on the results from this study, the best superheated steam roasting condition is at 220 ˚C for 20 min (medium roast to achieve a maximum antioxidant activity and highest phenolic content.

  20. Investigation of effects of chemical dosing on fuel consumption in central heating systems with superheated water

    Energy Technology Data Exchange (ETDEWEB)

    Bilen, Kemal [Kirikkale University, Engineering Faculty, Mechanical Engineering Department, Kirikkale (Turkey); email: kemal.bilen92@gmail.com

    2011-07-01

    In Turkey, a significant percentage of energy is consumed by buildings and heating accounts for most of it. These is therefore a need to increase the efficiency of such systems. As a regional heating option, central heating systems with superheated water are preferred and chemical dosing of these systems has become prevalent in recent years. This study analyses the energy and exergy of a superheated water, central heating system operated on natural gas, on a university campus with a population of 15000 people, and investigates the effect of chemical dosing on their efficiencies. The study results showed that the average energy and exergy efficiencies of the system were 92.07% and 62.45%, respectively. The results also demonstrated that there was a 5.21% and 2.74% increase in hourly gas consumption when the dosing concentration was changed from 5 ppm to 101 ppm and 50 ppm to 101 ppm, respectively. It was concluded that for lower fuel consumption, chemical dosing should be avoided.

  1. A position-sensitive neutron spectrometer/dosimeter based on pressurized superheated drop (bubble) detectors

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, F. E-mail: francesco.derrico@yale.edu; Nath, R.; Holland, S.K.; Lamba, M.; Patz, S.; Rivard, M.J

    2002-01-01

    A position-sensitive, superheated emulsion chamber (SEC) is introduced for three-dimensional (3D) spectrometry and dosimetry of fast neutrons. The detector is based on a fine suspension of octafluorocyclobutane droplets emulsified in a tissue-equivalent gel. This gel is highly viscous and immobilizes the bubbles at the location of their formation. At an operating temperature of 35 deg.C, the droplets are moderately superheated and their evaporation is nucleated by the densely ionizing products of fast neutron interactions, with no response to sparsely ionizing radiations. Thus, when a neutron emitter such as a {sup 252}Cf brachytherapy source is inserted in the SEC, a bubble distribution forms around the source and makes the neutron field visible. The SEC is operated at different externally applied pressures that correspond to different response thresholds. These responses form a virtually orthogonal matrix which is suitable for spectrometry and allows the use of effective few channel unfolding procedures, yielding the spatial dependence of absorbed dose and neutron energy spectra in-tissue. Bubble spatial distributions in the chamber can be determined through optical tomography or magnetic resonance imaging (MRI). A 3D, steady-state MRI method has proven particularly effective for this purpose. After the imaging, the SEC can be pressurized above the halocarbon vapor tension in order to recondense the bubbles to the liquid phase. Within a few minutes, the device is annealed and ready to be used again for repeated measurements improving the bubble counting statistics.

  2. Intrinsic noise of a superheated droplet detector for neutron background measurements in massively shielded facilities

    Science.gov (United States)

    Fernandes, Ana C.; Morlat, Tomoko A.; Felizardo, Miguel; Kling, Andreas; Marques, José G.; Prudêncio, Maria I.; Marques, Rosa; Carvalho, Fernando P.; Roche, Ignácio Lázaro; Girard, Thomas A.

    2017-09-01

    Superheated droplet detectors are a promising technique to the measurement of low-intensity neutron fields, as detectors can be rendered insensitive to minimum ionizing radiations. We report on the intrinsic neutron-induced signal of C2ClF5 devices fabricated by our group that originate from neutron- and alpha-emitting impurities in the detector constituents. The neutron background was calculated via Monte Carlo simulations using the MCNPX-PoliMi code in order to extract the recoil distributions following neutron interaction with the atoms of the superheated liquid. Various nuclear techniques were employed to characterise the detector materials with respect to source isotopes (238U, 232Th and 147Sm) for the normalisation of the simulations and also light elements (B, Li) having high (α, n) neutron production yields. We derived a background signal of 10-3 cts/day in a 1 liter detector of 1-3 wt.% C2ClF5, corresponding to a detection limit in the order of 10-8 n cm-2s-1. Direct measurements in a massively shielded underground facility for dark matter search have confirmed this result. With the borosilicate detector containers found to be the dominant background source in current detectors, possibilities for further noise reduction by 2 orders of magnitude based on selected container materials are discussed.

  3. Exhaust hood for steam turbines-single-flow arrangement

    Institute of Scientific and Technical Information of China (English)

    Michal HOZNEDL; Ladislav TAJC; Jaroslav KREJCIK; Lukas BEDNAR; Kamil SEDLAK; Jiri LINHART

    2009-01-01

    In the past, increased attention was given to the development of an optimal shape for the inlet part of LP turbine casings in SKODA POWER. A double-flow design is typically used for high power output turbines. An optimized shape for the internal diffuser has been found,which transforms the kinetic energy of steam into increased pressure, thus effectively increasing the thermo-dynamic efficiency of the stage. Some conclusions have been drawn from laboratory experiments, others derived directly from on-site measurements at power plants. The conclusions from the development of double-flow turbines form the basis for the design of the single-flow turbine arrangement. Single-flow design is typically used for lower output turbines. There are still some limitations in applying this arrangement. The designer needs to resolve the bearing position and how to ensure access to them. Reinforcing the ribs and supports are used, therefore, to ensure the rigidity of the entire casing. The optimization of the single-flow diffuser shape is therefore the subject of the study presented below.

  4. Fever of undetermined etiology after cleaning of steam turbine condensers.

    Science.gov (United States)

    Deubner, D C; Gilliam, D K

    1977-01-01

    Two outbreaks of a febrile syndrome marked by chills, headaches, myalgia, nausea, and malaise occurred in workers who had cleaned the steam condensers of electric power turbines. Mean incubation period was 38 hours. Twenty-two of twenty-three exposed men became ill. Clinical and environmental investigation failed to reveal the etiology of the outbreaks. The circumstances and clinical syndrome have points of similarity to fever following inhalation of metal fumes and low-grade, stained cotton dust, and to Pontiac fever.

  5. Conventional and intelligent generalized supervisory control for combined cycle generating power stations.; Control supervisiorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, Miguel A; Sanchez P, Marino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gonzalez Rubio S, Jose L [Cento Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

    2005-07-01

    Under the expectations of expansion of electric power generation in Mexico, this work exposes the development of a conventional and intelligent generalized supervisory control (CSG) for a combined cycle generation power plant. This one allows to obtain the optimal operation of the power plant through the automatic starting of the generating units and to obtain the maximum possible amount of electrical power in automatic and safe form. For the development of the CSG a control loop by temperature was implemented for the gas turbine system and a control loop by strangled pressure for the gas turbine and a control loop by strangled pressure for the steam turbine. The design of these supervisory systems was made with base in the critical limits on the involved variables of the process: blading average temperature, for the gas turbine (GT) and strangled pressure for the steam turbine (ST) [Spanish] Bajo estas expectativas de expansion de generacion de energia en Mexico, este trabajo expone el desarrollo de un control supervisorio generalizado (CSG) para una central generacion de ciclo combinado. Este permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas y un lazo de control por presion estrangulada para la turbina de gas y un lazo de control por presion estrangulada para la turbina de vapor. El diseno de estos sistemas supervisorio se realizo con base en los limites criticos de las variables del proceso involucradas: temperatura promedio de empaletado para la turbina de gas (TG) y presion estrangulada para la turbina de vapor (TV)

  6. Design for the 145MW blast furnance gas firing gas turbine combined cycle plant

    Energy Technology Data Exchange (ETDEWEB)

    Takano, H. (Kawasaki Steel Corp., Chiba (Japan). Technical Research Lab.); Kitauchi, Y.; Hiura, H. (Mitsubishi Heavy Industries Ltd., Takasago, Hyogo (Japan). Takasago Works)

    1988-01-01

    A 145 MW blast furnance gas firing gas turbine combined cycle plant was designed and installed in a steel works of Japan as a repowering unit. A 124 MW large scale gas turbine with turbine inlet temperature 1150{sup {degrees}}C (1423 K) was adopted as a core engine for the combined cycle plant. The fuel of this gas turbine is blast furnace gas mixed with coke oven gas which are byproducts in steel works, and the calorific value of the mixed gas to be controlled is about 1000 kcal/Nm{sup 3} (4187 kJ/Nm{sup 3}). A specially designed multi-cannular type combustor was developed to burn such a low BTV fuel. The gas turbine, generator, steam turbine and fuel gas compressor are connected to make a single shaft configuration. As a result of this introducing the gas turbine combined cycle plant, the plant thermal efficiency was achieved above 45% (at NET) and the total electricity generation in the works is increased from 243 MW to 317 MW. This paper describes the design features of this combined cycle plant.

  7. Integrated gasification combined cycle (IGCC) process simulation and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Emun, F.; Gadalla, M.; Majozi, T.; Boer, D. [University of Rovira & Virgili, Tarragona (Spain). Dept. of Chemical Engineering

    2010-03-05

    The integrated gasification combined cycle (IGCC) is an electrical power generation system which offers efficient generation from coal with lower effect on the environment than conventional coal power plants. However, further improvement of its efficiency and thereby lowering emissions are important tasks to achieve a more sustainable energy production. In this paper, a process simulation tool is proposed for simulation of IGCC. This tool is used to improve IGCC's efficiency and the environmental performance through an analysis of the operating conditions, together with process integration studies. Pinch analysis principles and process integration insights are then employed to make topological changes to the flowsheet to improve the energy efficiency and minimize the operation costs. Process data of the Texaco gasifier and the associated plants (coal preparation, air separation unit, gas cleaning, sulfur recovery, gas turbine, steam turbine and the heat recovery steam generator) are considered as a base case, and simulated using Aspen Plus. The results of parameter analysis and heat integration studies indicate that thermal efficiency of 45% can be reached, while a significant decrease in CO{sub 2} and SOx emissions is observed. The CO{sub 2} and SOx emission levels reached are 698 kg/MWh and 0.15 kg/MWh, respectively. Application of pinch analysis determines energy targets, and also identifies potential modifications for further improvement to overall energy efficiency. Benefits of energy integration and steam production possibilities can further be quantified. Overall benefits can be translated to minimum operation costs and atmospheric emissions.

  8. PHYSICOCHEMICAL PROPERTY CHANGES AND ENZYMATIC HYDROLYSIS ENHANCEMENT OF OIL PALM EMPTY FRUIT BUNCHES TREATED WITH SUPERHEATED STEAM

    Directory of Open Access Journals (Sweden)

    Ezyana Kamal Bahrin,

    2012-02-01

    Full Text Available The effect of superheated steam treatment on oil palm empty fruit bunches (OPEFB was investigated in terms of physicochemical property changes and enzymatic hydrolysis enhancement. The experimental treatment was carried out at different temperatures (140-210°C and durations (20-90 min. Results showed that as the superheated steam temperature and time increased, the size distribution also changed, resulting in more small particles. Analysis on the surface texture, color, and mechanical properties of the treated OPEFB also showed that significant changes resulted due to the superheated steam treatment. In support to this, Fourier Transform Infrared (FTIR spectroscopy and thermogravimetric (TG analyses showed that solubilization and removal of the hemicelluloses component also took place. As a result of this phenomenon, higher total sugar and glucose yield was achieved once the treated OPEFB was subjected to enzymatic hydrolysis. This suggests that superheated steam treatment could enhance OPEFB structure degradation for the preparation of a suitable substrate in order to produce a higher glucose yield in the enzymatic hydrolysis process.

  9. Comparison of Organic Rankine Cycle Under Varying Conditions Using Turbine and Twin-Screw Expanders

    OpenAIRE

    Read, M. G.; Smith, I K; Stosic, N.

    2015-01-01

    A multi-variable optimization program has been developed to investigate the performance of Organic Rankine Cycles (ORCs) for low temperature heat recovery applications. This cycle model contains detailed thermodynamic models of the system components, and the methods used to match the operation of the expander to the requirements of the cycle are described. Two types of ORC system are considered; one containing a turbine to expand dry saturated or superheated vapour, and one with a twin-screw ...

  10. Technical and financial analysis of combined cycle gas turbine

    Directory of Open Access Journals (Sweden)

    Khan Arshad Muhammad

    2013-01-01

    Full Text Available This paper presents technical and financial models which were developed in this study to predict the overall performance of combined cycle gas turbine plant in line with the needs of independent power producers in the liberalized market of power sector. Three similar sizes of combined cycle gas turbine power projects up to 200 Megawatt of independent power producers in Pakistan were selected in-order to develop and drive the basic assumptions for the inputs of the models in view of prevailing Government of Pakistan’s two components of electricity purchasing tariff that is energy purchase price and capacity purchase price at higher voltage grid station terminal from independent power producers. The levelized electricity purchasing tariff over life of plant on gaseous fuel at 60 percent plant load factor was 6.47 cent per kilowatt hour with energy purchase price and capacity purchase prices of 3.54 and 2.93 cents per kilowatt hour respectively. The outcome of technical models of gas turbine, steam turbine and combined cycle gas turbine power were found in close agreement with the projects under consideration and provides opportunity of evaluation of technical and financial aspects of combined cycle power plant in a more simplified manner with relatively accurate results. At 105 Celsius exit temperature of heat recovery steam generator flue gases the net efficiency of combined cycle gas turbine was 48.8 percent whereas at 125 Celsius exit temperature of heat recovery steam generator flue gases it was 48.0 percent. Sensitivity analysis of selected influential components of electricity tariff was also carried out.

  11. Analysis of a reheat gas turbine cycle with chemical recuperation using Aspen

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, S.; Kane, N`Diaye [ISITEM - Lab. d`Energetique, Nantes (France)

    1996-11-01

    Present-day high performance gas turbine based cycles use the combined cycle concept in which the heat in the hot turbine exhaust stream is used to raise steam which can be used to generate electricity using a steam turbine. Recent attention has focused in particular on the chemical heat recovery concept.The potential benefits of such cycles include high conversion efficiency, ultra-low NO{sub x} emission levels (less than 1 ppm) and high power density per unit of land. The low thermal NO{sub X} emissions result from the presence of hydrogen in the reformed fuel gas, which enables combustion at lower flame temperatures. Thus, a CRGT (Chemically Recuperated Gas Turbine) cycle can meet the strictest NO{sub x} limits in operation today without the need for selective catalytic reduction. Such environmental characteristics are the primary reason fuelling current interest in CRGT cycles. For design reasons, reheat combustors cannot be easily adapted to stationary gas turbines, and until recently the CRGT cycle seemed to be limited to aeroderivative gas turbine applications. However, ABB recently unveiled its new GT26 series stationary gas turbines using staged expansion with reheat combustion, allowing high thermal efficiencies with relatively low turbine inlet temperatures. This type of turbine appears particularly well-suited for chemical heat recovery. In this paper, we present a CRGT cycle based on a reheat gas turbine with key design features similar to those of ABB`s GT26 machine. The cycle analysis is performed using ASPEN+ process simulation software. The report includes a detailed first and second law analysis of the cycle. The results confirm that the energy conversion efficiencies of CRGT cycles cannot rival with the efficiencies achieved by state-of-the-art combined cycles. 12 refs, 3 figs, 5 tabs

  12. Searching for universal behaviour in superheated droplet detector with effective recoil nuclei

    Indian Academy of Sciences (India)

    Mala Das; Susnata Seth

    2013-06-01

    Energy calibration of superheated droplet detector is discussed in terms of the effective recoil nucleus threshold energy and the reduced superheat. This provides a universal energy calibration curve valid for different liquids used in this type of detector. Two widely used liquids, R114 and C4F10, one for neutron detection and the other for weakly interacting massive particles (WIMPs) dark matter search experiment, have been compared. Liquid having recoil nuclei with larger values of linear energy transfer (LET) provides better neutron- discrimination. Gamma () response of C4F10 has also been studied and the results are discussed. Behaviour of nucleation parameter with the effective recoil nucleus threshold energy and the reduced superheat have been explored.

  13. Influence of element Cu on hydrogen content in superheated aluminum melt

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrogen content in molten Al-Cu alloy increases remarkably when the temperature of the melt rises to about 780  ℃. The effects of alloying element are theoretically analyzed in terms of Wagner interaction parameter. Furthermore, analyses indicate that the alloy element Cu plays an important role in the hydrogen content in superheated Al-Cu alloy melt below about 780  ℃. The conclusion is drawn that the degree of gassing in molten Al-Cu alloy is bound up with the properties of oxide film of Al alloy melts. The results make it clear that the hydrogen content in the molten aluminum reduces with increasing element Cu dissolved in aluminum melts at the same temperature.

  14. Explosive boiling of a metallic glass superheated by nanosecond pulse laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M. Q., E-mail: mqjiang@imech.ac.cn, E-mail: lhdai@lnm.imech.ac.cn [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Materials Physics, Westfälische Wilhelms-Universität Münster, Münster 48149 (Germany); Wei, Y. P. [Key Laboratory of Mechanics in Fluid Solid Coupling Systems, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Wilde, G. [Institute of Materials Physics, Westfälische Wilhelms-Universität Münster, Münster 48149 (Germany); Dai, L. H., E-mail: mqjiang@imech.ac.cn, E-mail: lhdai@lnm.imech.ac.cn [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-01-12

    We report an explosive boiling in a Zr-based (Vitreloy 1) bulk metallic glass irradiated by a nanosecond pulse laser with a single shot. This critical phenomenon is accompanied by the ejection of high-temperature matter from the target and the formation of a liquid-gas spinodal pattern on the irradiated area. An analytical model reveals that the glassy target experiences the normal heating (melting) and significant superheating, eventually culminating in explosive boiling near the spinodal limit. Furthermore, the time lag of nucleation and the critical radius of vapor bubbles are theoretically predicted, which are in agreement with the experimental observations. This study provides the investigation on the instability of a metallic glass liquid near the thermodynamic critical temperature.

  15. A neutron spectrometer based on temperature variations in superheated drop compositions

    CERN Document Server

    Apfel, R E

    2002-01-01

    The response of superheated drop detectors (SDDs) to neutron radiation varies in a self-consistent manner with variations in temperature and pressure, making such compositions suitable for neutron spectrometry. The advantage of this approach is that the response functions of candidate materials versus energy as the temperature or pressure is varied are nested and have distinct thresholds, with no thermal neutron response. These characteristics permit unfolding without the uncertainties associated with other spectrometry techniques, where multiple solutions are possible, thus requiring an initial guess of the spectrum. A spectrometer was developed based on the well-established technology for acoustic sensing of bubble events interfaced with a proportional-integral-derivative temperature controller. The active monitor for neutrons, called REMbrandt sup T sup M , was used as the platform for controlling temperature on a SDD probe and for data acquisition, thereby automating the process of measuring the neutron e...

  16. Effect of Melt Superheating Treatment on the Latent Heat Release of Sn

    Science.gov (United States)

    Xu, Junfeng; Dang, Bo; Fan, Dandan; Jian, Zengyun

    2017-03-01

    The accuracy of the baseline evaluation is of importance for calculating the transition enthalpy such as the latent heat of the crystallization. This study demonstrates the modified method of the equivalent non-latent heat baseline, by which the transition enthalpy can be measured accurately according to the transition peak in differential scanning calorimetric curve. With this method, the effect of melt superheating treatment time on the latent heat release upon the solidification of tin is investigated. The results show that the latent heat increases by increasing the treatment time, and is close to a constant when the treatment time is large enough, indicating the homogeneous system. And then, a simple model is established to describe the changes of the crystallization latent heat with the treatment time, which is confirmed by the experimental data of Sn.

  17. Superheated-drop (bubble) neutron detectors and their compliance with ICRP-60

    Energy Technology Data Exchange (ETDEWEB)

    d' Errico, F. (Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari Istituto Nazionale di Fisica Nucleare, Pisa (Italy)); Alberts, W.G. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany))

    1994-01-01

    Several devices based on superheated-drop detector technology have become available almost simultaneously with the release of new ICRP and ICRU publications. Given this circumstance, a study of the characteristics of the system has been undertaken by the authors considering the revised recommendations for neutron dosimetry. The dose equivalent response in free air has been examined experimentally as a function of energy from thermal up to 70 MeV neutrons, and its dependence on the angle of incidence has been tested on a phantom at 0.57 MeV. Some results are discussed with respect to lower limit of detection, temperature sensitivity, [gamma] discrimination, batch-to-batch uniformity, and reproducibility. Some conclusions in terms of advantages, limitations and possible applications of the system are presented. (author).

  18. Combined cycle power unit with a binary system based on waste geothermal brine at Mutnovsk geothermal power plant

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Nikol'skii, A. I.; Semenov, V. N.

    2016-06-01

    The Russian geothermal power systems developed in the last few decades outperform their counterparts around the world in many respects. However, all Russian geothermal power stations employ steam as the geothermal fluid and discard the accompanying geothermal brine. In reality, the power of the existing Russian geothermal power stations may be increased without drilling more wells, if the waste brine is employed in combined cycle systems with steam and binary turbine units. For the example of the 50 MW Mutnovsk geothermal power plant, the optimal combined cycle power unit based on the waste geothermal brine is considered. It is of great interest to determine how the thermodynamic parameters of the secondary steam in the expansion unit and the pressure in the condenser affect the performance of the equipment in the combined cycle power unit at Mutnovsk geothermal power plant. For the utilization of the waste geothermal brine at Mutnovsk geothermal power plant, the optimal air temperature in the condensers of the combined cycle power unit is +5°C. The use of secondary steam obtained by flashing of the geothermal brine at Mutnovsk geothermal power plant 1 at a pressure of 0.2 MPa permits the generation of up to 8 MW of electric power in steam turbines and additional power of 5 MW in the turbines of the binary cycle.

  19. Antifreeze protein-induced superheating of ice inside Antarctic notothenioid fishes inhibits melting during summer warming.

    Science.gov (United States)

    Cziko, Paul A; DeVries, Arthur L; Evans, Clive W; Cheng, Chi-Hing Christina

    2014-10-07

    Antifreeze proteins (AFPs) of polar marine teleost fishes are widely recognized as an evolutionary innovation of vast adaptive value in that, by adsorbing to and inhibiting the growth of internalized environmental ice crystals, they prevent death by inoculative freezing. Paradoxically, systemic accumulation of AFP-stabilized ice could also be lethal. Whether or how fishes eliminate internal ice is unknown. To investigate if ice inside high-latitude Antarctic notothenioid fishes could melt seasonally, we measured its melting point and obtained a decadal temperature record from a shallow benthic fish habitat in McMurdo Sound, Antarctica. We found that AFP-stabilized ice resists melting at temperatures above the expected equilibrium freezing/melting point (eqFMP), both in vitro and in vivo. Superheated ice was directly observed in notothenioid serum samples and in solutions of purified AFPs, and ice was found to persist inside live fishes at temperatures more than 1 °C above their eqFMP for at least 24 h, and at a lower temperature for at least several days. Field experiments confirmed that superheated ice occurs naturally inside wild fishes. Over the long-term record (1999-2012), seawater temperature surpassed the fish eqFMP in most summers, but never exceeded the highest temperature at which ice persisted inside experimental fishes. Thus, because of the effects of AFP-induced melting inhibition, summer warming may not reliably eliminate internal ice. Our results expose a potentially antagonistic pleiotropic effect of AFPs: beneficial freezing avoidance is accompanied by melting inhibition that may contribute to lifelong accumulation of detrimental internal ice crystals.

  20. Non-Intrusive, Real-Time, On-Line Temperature Sensor for Superheated Hydrogen at High Pressure and High Flow Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The SSC needs a hydrogen temperature sensor that can provide high accuracy, fast response and can be operated on a superheated hydrogen (SHH2) environment. This will...

  1. Promising Direction of Perfection of the Utilization Combine Cycle Gas Turbine Units

    Directory of Open Access Journals (Sweden)

    Gabdullina Albina I.

    2017-01-01

    Full Text Available Issues of improving the efficiency of combined cycle gas turbines (CCGT recovery type have been presented. Efficiency gas turbine plant reaches values of 45 % due to rise in temperature to a gas turbine to 1700 °C. Modern technologies for improving the cooling gas turbine components and reducing the excess air ratio leads to a further increase of the efficiency by 1-2 %. Based on research conducted at the Tomsk Polytechnic University, it shows that the CCGT efficiency can be increased by 2-3 % in the winter time due to the use of organic Rankine cycle, low-boiling substances, and air-cooled condensers (ACC. It is necessary to apply the waste heat recovery with condensation of water vapor from the flue gas, it will enhance the efficiency of the CCGT by 2-3 % to increase the efficiency of the heat recovery steam boiler (HRSB to 10-12 %. Replacing electric pumps gas turbine engine (GTE helps to reduce electricity consumption for auxiliary needs CCGT by 0.5-1.5 %. At the same time the heat of flue gas turbine engine may be useful used in HRSB, thus will increase the capacity and efficiency of the steam turbine.

  2. Thermal Hydraulic Design and Analysis of a Water-Cooled Ceramic Breeder Blanket with Superheated Steam for CFETR

    Science.gov (United States)

    Cheng, Xiaoman; Ma, Xuebin; Jiang, Kecheng; Chen, Lei; Huang, Kai; Liu, Songlin

    2015-09-01

    The water-cooled ceramic breeder blanket (WCCB) is one of the blanket candidates for China fusion engineering test reactor (CFETR). In order to improve power generation efficiency and tritium breeding ratio, WCCB with superheated steam is under development. The thermal-hydraulic design is the key to achieve the purpose of safe heat removal and efficient power generation under normal and partial loading operation conditions. In this paper, the coolant flow scheme was designed and one self-developed analytical program was developed, based on a theoretical heat transfer model and empirical correlations. Employing this program, the design and analysis of related thermal-hydraulic parameters were performed under different fusion power conditions. The results indicated that the superheated steam water-cooled blanket is feasible. supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy of China (Nos. 2013GB108004, 2014GB122000 and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  3. Biphase turbine bottoming cycle for a diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.; Hays, L.

    1977-02-15

    Application of a two-phase turbine system to waste heat recovery was examined. Bottoming cycle efficiencies ranging from 15 to 30% were calculated for a 720/sup 0/F diesel exhaust temperature. A single stage demonstration unit, designed for non-toxic fluids (water and DowTherm A) and for atmospheric seals and bearings, had a cycle efficiency of 23%. The net output power was 276 hp at 8,100 rpm, increasing the total shaft power from 1,800 hp for the diesel alone, to 2,076 hp for the combined system. A four stage organic turbine, for the same application, had a rotational speed of 14,700 rpm while a four stage steam turbine had 26,000 rpm. Fabrication drawings were prepared for the turbine and nozzle. The major improvement leading to higher cycle efficiency and lower turbine rpm was found to be the use of a liquid component with lower sensible heat. A reduction in capital cost was found to result from the use of a contact heat exchanger instead of tube-fin construction. The cost for a contact heat exchanger was only $35-52/kWe compared to $98/kWe for a tube-fin heat exchanger. Design drawings and materials list were prepared. A program resulting in the demonstration of a two-phase bottoming system was planned and the required cost estimated. The program would result in a feasibility test of the nozzle and turbine at the end of the first year, a laboratory performance test of the bottoming system by the end of the second year and a field demonstration test and laboratory endurance test of the bottoming system during the third year. The blowdown test rig for the first year's program and test turbine were designed.

  4. Evaluation of the thermal effect on separation selectivity in anion-exchange processes using superheated water ion-exchange chromatography.

    Science.gov (United States)

    Shibukawa, Masami; Taguchi, Akihiko; Suzuki, Yusuke; Saitoh, Kazunori; Hiaki, Toshihiko; Yarita, Takashi

    2012-07-07

    The thermal effect on retention and separation selectivity of inorganic anions and aromatic sulfonate ions in anion-exchange chromatography is studied on a quaternized styrene-divinylbenzene copolymer anion-exchange column in the temperature range of 40-120 °C using superheated water chromatography. The selectivity coefficient for a pair of identically charged anions approaches unity as temperature increases provided the ions have the same effective size, such that the retention of an analyte ion decreases with an increase in temperature when the analyte ion has stronger affinity for the ion-exchanger than that of the eluent counterion, whereas it increases when it has weaker affinity. The change in anion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions. At elevated temperatures, especially in superheated water, the electrostatic interaction or association of the ions with the fixed ion in the resin phase becomes a predominant factor resulting in a different separation selectivity from that obtained at ambient temperature.

  5. Emission estimation of neat paradise tree oil combustion assisted with superheated hydrogen in a 4-stroke natural aspirated DICI engine

    Directory of Open Access Journals (Sweden)

    Sundararajan Karthikayan

    2016-01-01

    Full Text Available This research work investigates the use of neat paradise tree oil in a 4-stroke natural aspirated direct injection compression ignition engine assisted with the help of super-heated hydrogen (hydrogen in gaseous state or above its saturation temperature as a combustion improver. The high calorific gaseous fuel hydrogen gas was used as a combustion improver and admitted into the engine during the suction stroke. A 4-stroke single cylinder Diesel engine was chosen and its operating parameters were suitably modified. Neat paradise tree oil was admitted through standard injector of the engine and hydrogen was admitted through induction manifold. Inducted super-heated hydrogen was initiated the intermediate compounds combustion of neat paradise tree oil. This process offers higher temperature combustion and results in complete combustion of heavier molecules of neat paradise tree oil within shorter duration. The results of the experiment reveal that 40% higher NOx, 20% lower smoke, 5% lower CO, and 45% lower HC than that of neat paradise tree oil fuel operation and the admission of superheated hydrogen has improved the combustion characteristics of neat paradise tree oil. The investigation successfully proved that the application of neat paradise tree oil with 15% of hydrogen improver is possible under a regular Diesel engine with minimal engine modification.

  6. Role of superheated water in the origin of life; Seimei no kigen ni hatashita nessui no yakuwari

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, H. [Mitsubishi Kasei Corp., Tokyo (Japan)

    1994-09-01

    High-temperature hot water environments at the bottom of seas are drawing attentions recently. This paper describes the consideration on actions of superheated water that contribute to the origin of life. Gushing of superheated water from cracks in ocean bottoms is discovered in the eastern Pacific oceanic rises, Okinawa and other parts of the world. Jet holes are characterized by having higher concentration in such a reducing gas as methane (CH4), and being more reducing than the surrounding sea water. Concentrations of ions of metals such as Fe is 1000 times or more higher than that in the sea water, which is advantageous for organics composing reaction in the superheated water. An investigation has been carried out on organics synthesis under the environment where ocean bottom hot water jet holes exist. Sea waters were manufactured on an experimental basis by using a hot water jetting hole model. As a result of various discussions, proteins such as glycine, amino acid, and non-protein {beta}-alanine were produced. With respect to the evolution of chemical actions, high-pressure heating of mixed solution containing glycine has generated microsphere. Temperature dependence of peptide generation was also made clear. Regarding the hydrogen fugacity at the actual jetting holes, the stability of amino acid is remarkably increased when 1% H2 is added into the pressurizing N2. 6 refs., 2 figs.

  7. Superheated water ion-exchange chromatography: an experimental approach for interpretation of separation selectivity in ion-exchange processes.

    Science.gov (United States)

    Shibukawa, Masami; Shimasaki, Tomomi; Saito, Shingo; Yarita, Takashi

    2009-10-01

    Cation-exchange selectivity for alkali and alkaline-earth metal ions and tetraalkylammonium ions on a strongly acidic sulfonic acid cation-exchange resin has been investigated in the temperature range of 40-175 degrees C using superheated water chromatography. Dependence of the distribution coefficient (ln KD) on the reciprocal of temperature (1/T) is not linear for most of the ions studied, and the selectivity coefficient for a pair of alkali metal ions or that of alkaline-earth metal ions approaches unity as temperature increases. On the other hand, the retention order of tetraalkylammonium ions is reversed at 160 degrees C or above when eluted with Na2SO4 aqueous solution and the larger ions are eluted faster than the smaller ones contrary to the retention order obtained at ambient temperature. The change in ion-exchange selectivity with temperature observed with superheated water chromatography has been discussed on the basis of the effect of temperature on hydration of the ions and specific adsorption or distribution of ionic species between the external solution and ion-exchange resin. In superheated water, the electrostatic interaction or association of the ions with the fixed ion becomes a predominant mechanism resulting in different separation selectivity from that obtained at ambient temperature.

  8. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part A: Methodology and reference cases

    Science.gov (United States)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-08-01

    Driven by the search for the highest theoretical efficiency, in the latest years several studies investigated the integration of high temperature fuel cells in natural gas fired power plants, where fuel cells are integrated with simple or modified Brayton cycles and/or with additional bottoming cycles, and CO2 can be separated via chemical or physical separation, oxy-combustion and cryogenic methods. Focusing on Solid Oxide Fuel Cells (SOFC) and following a comprehensive review and analysis of possible plant configurations, this work investigates their theoretical potential efficiency and proposes two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs integrated with a steam turbine or gas turbine cycle. The SOFC works at atmospheric or pressurized conditions and the resulting power plant exceeds 78% LHV efficiency without CO2 capture (as discussed in part A of the work) and 70% LHV efficiency with substantial CO2 capture (part B). The power plants are simulated at the 100 MW scale with a complete set of realistic assumptions about fuel cell (FC) performance, plant components and auxiliaries, presenting detailed energy and material balances together with a second law analysis.

  9. Development of a dynamic simulator for a natural gas combined cycle (NGCC) power plant with post-combustion carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Liese, E.; Zitney, S.

    2012-01-01

    The AVESTAR Center located at the U.S. Department of Energy’s National Energy Technology Laboratory and West Virginia University is a world-class research and training environment dedicated to using dynamic process simulation as a tool for advancing the safe, efficient and reliable operation of clean energy plants with CO{sub 2} capture. The AVESTAR Center was launched with a high-fidelity dynamic simulator for an Integrated Gasification Combined Cycle (IGCC) power plant with pre-combustion carbon capture. The IGCC dynamic simulator offers full-scope Operator Training Simulator (OTS) Human Machine Interface (HMI) graphics for realistic, real-time control room operation and is integrated with a 3D virtual Immersive Training Simulator (ITS), thus allowing joint control room and field operator training. The IGCC OTS/ITS solution combines a “gasification with CO{sub 2} capture” process simulator with a “combined cycle” power simulator into a single high-performance dynamic simulation framework. This presentation will describe progress on the development of a natural gas combined cycle (NGCC) dynamic simulator based on the syngas-fired combined cycle portion of AVESTAR’s IGCC dynamic simulator. The 574 MW gross NGCC power plant design consisting of two advanced F-class gas turbines, two heat recovery steam generators (HRSGs), and a steam turbine in a multi-shaft 2x2x1 configuration will be reviewed. Plans for integrating a post-combustion carbon capture system will also be discussed.

  10. Sequential microwave superheated water extraction of mannans from spent coffee grounds.

    Science.gov (United States)

    Passos, Cláudia P; Moreira, Ana S P; Domingues, M Rosário M; Evtuguin, Dmitry V; Coimbra, Manuel A

    2014-03-15

    The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 °C for 3 min. With MAE3, mannose recovery achieved 48%, increasing to 56% by MAE4, and reaching a maximum of 69% with MAE5. Glycosidic-linkage analysis showed that in MAE3 mainly galactomannans were recovered, while debranched galactomannans were recovered with MAE4 and MAE5. With increasing the number of extractions, the average degree of polymerization of the mannans decreased, as observed by size-exclusion chromatography and by methylation analysis. Scanning electron microscopy images showed a decrease on cell walls thickness. After final MAE5, the remaining un-extracted insoluble material, representing 22% of the initial SCG, was composed mainly by cellulose (84%).

  11. Modification of oil palm mesocarp fiber characteristics using superheated steam treatment.

    Science.gov (United States)

    Nordin, Noor Ida Amalina Ahamad; Ariffin, Hidayah; Andou, Yoshito; Hassan, Mohd Ali; Shirai, Yoshihito; Nishida, Haruo; Yunus, Wan Zin Wan; Karuppuchamy, Subbian; Ibrahim, Nor Azowa

    2013-07-30

    In this study, oil palm mesocarp fiber (OPMF) was treated with superheated steam (SHS) in order to modify its characteristics for biocomposite applications. Treatment was conducted at temperatures 190-230 °C for 1, 2 and 3 h. SHS-treated OPMF was evaluated for its chemical composition, thermal stability, morphology and crystallinity. OPMF treated at 230 °C exhibited lower hemicellulose content (9%) compared to the untreated OPMF (33%). Improved thermal stability of OPMF was found after the SHS treatment. Moreover, SEM and ICP analyses of SHS-treated OPMF showed that silica bodies were removed from OPMF after the SHS treatment. XRD results exhibited that OPMF crystallinity increased after SHS treatment, indicating tougher fiber properties. Hemicellulose removal makes the fiber surface more hydrophobic, whereby silica removal increases the surface roughness of the fiber. Overall, the results obtained herewith suggested that SHS is an effective treatment method for surface modification and subsequently improving the characteristics of the natural fiber. Most importantly, the use of novel, eco-friendly SHS may contribute to the green and sustainable treatment for surface modification of natural fiber.

  12. Influence of Elemental Iron on Hydrogen Content in Superheated Aluminum-iron Melts

    Institute of Scientific and Technical Information of China (English)

    HU Li-na; BIAN Xiu-fang; ANANDA Mahto; DUAN You-feng

    2004-01-01

    The hydrogen content in liquid binary aluminum alloys with 1,3,5 and 8 wt% iron has been determined in the temperature range from 973K to 1103K.The hydrogen content in molten Al-Fe alloys increases remarkably when the temperature of the melt rises to about 1053K.This work indicates that the alloying element iron plays an important role in hydrogen content in superheated Al-Fe alloy melts below about 1053K.The results make it clear that the hydrogen content in the melt aluminum reduces with the increasing element levels.A conclusion is drawn that the degree of gassing in molten Al-Fe alloys is bound up with the properties of oxide film of aluminum alloy melts.The element iron has no effect on the compact structure of oxide film in aluminum melts.The effects of alloying element are theoretically analyzed in terms of Wagner interaction parameter.According to the values of the first order interaction parameter,it is concluded that the interaction between iron atom and aluminum is much stronger than that between hydrogen atom and aluminum,and the addition of the alloying element decreases the affinity of liquid aluminum for hydrogen.

  13. Investigation of coherent structures in a superheated jet using decomposition methods

    Science.gov (United States)

    Sinha, Avick; Gopalakrishnan, Shivasubramanian; Balasubramanian, Sridhar

    2016-11-01

    A superheated turbulent jet, commonly encountered in many engineering flows, is complex two phase mixture of liquid and vapor. The superposition of temporally and spatially evolving coherent vortical motions, known as coherent structures (CS), govern the dynamics of such a jet. Both POD and DMD are employed to analyze such vortical motions. PIV data is used in conjunction with the decomposition methods to analyze the CS in the flow. The experiments were conducted using water emanating into a tank containing homogeneous fluid at ambient condition. Three inlet pressure were employed in the study, all at a fixed inlet temperature. 90% of the total kinetic energy in the mean flow is contained within the first five modes. The scatterplot for any two POD coefficients predominantly showed a circular distribution, representing a strong connection between the two modes. We speculate that the velocity and vorticity contours of spatial POD basis functions show presence of K-H instability in the flow. From DMD, eigenvalues away from the origin is observed for all the cases indicating the presence of a non-oscillatory structure. Spatial structures are also obtained from DMD. The authors are grateful to Confederation of Indian Industry and General Electric India Pvt. Ltd. for partial funding of this project.

  14. A neutron spectrometer based on temperature variations in superheated drop compositions

    Energy Technology Data Exchange (ETDEWEB)

    Apfel, Robert E. E-mail: robert.apfel@yale.edu; D' Errico, Francesco

    2002-01-01

    The response of superheated drop detectors (SDDs) to neutron radiation varies in a self-consistent manner with variations in temperature and pressure, making such compositions suitable for neutron spectrometry. The advantage of this approach is that the response functions of candidate materials versus energy as the temperature or pressure is varied are nested and have distinct thresholds, with no thermal neutron response. These characteristics permit unfolding without the uncertainties associated with other spectrometry techniques, where multiple solutions are possible, thus requiring an initial guess of the spectrum. A spectrometer was developed based on the well-established technology for acoustic sensing of bubble events interfaced with a proportional-integral-derivative temperature controller. The active monitor for neutrons, called REMbrandt{sup TM}, was used as the platform for controlling temperature on a SDD probe and for data acquisition, thereby automating the process of measuring the neutron energy spectrum. The new instrument, called REM-SPEC{sup TM}, implements and automates the original BINS approach: it adjusts the temperature of the SDD vial in increasing steps and measures the bubble event rate at each step. By using two distinct SDD materials with overlapping responses, the 0.1-20 MeV range of energies relevant to practical spectrometry is readily covered. Initial experiments with an Am-Be source validate the operational protocols of this device.

  15. Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe.

    Science.gov (United States)

    Kundan, Akshay; Nguyen, Thao T T; Plawsky, Joel L; Wayner, Peter C; Chao, David F; Sicker, Ronald J

    2017-03-03

    A wickless heat pipe was operated on the International Space Station to provide a better understanding of how the microgravity environment might alter the physical and interfacial forces driving evaporation and condensation. Traditional heat pipes are divided into three zones: evaporation at the heated end, condensation at the cooled end, and intermediate or adiabatic in between. The microgravity experiments reported herein show that the situation may be dramatically more complicated. Beyond a threshold heat input, there was a transition from evaporation at the heated end to large-scale condensation, even as surface temperatures exceeded the boiling point by 160 K. The hotter the surface, the more vapor was condensed onto it. The condensation process at the heated end is initiated by thickness and temperature disturbances in the thin liquid film that wet the solid surface. Those disturbances effectively leave the vapor "superheated" in that region. Condensation is amplified and sustained by the high Marangoni stresses that exist near the heater and that drive liquid to cooler regions of the device.

  16. Kinetics of the reaction between H{sup ·} and superheated water probed with muonium

    Energy Technology Data Exchange (ETDEWEB)

    Alcorn, Chris D. [Department of Chemistry and Biochemistry, Mount Allison University, Sackville, New Brunswick E4L 1G8 (Canada); Brodovitch, Jean-Claude [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Percival, Paul W. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Smith, Marisa [Department of Chemistry and Biochemistry, Mount Allison University, Sackville, New Brunswick E4L 1G8 (Canada); Ghandi, Khashayar, E-mail: kghandi@mta.ca [Department of Chemistry and Biochemistry, Mount Allison University, Sackville, New Brunswick E4L 1G8 (Canada)

    2014-05-19

    Highlights: • Rate constants for reactions of H with water resolve a controversy. • H reacts with superheated water via two channels. • The findings have important implications for the safety of some nuclear power reactors. - Abstract: Safe operation of supercritical water-cooled reactors requires knowledge of the kinetics of transient species formed by the radiolysis of water in the range 300–650 °C. Using muonium, it is possible to study aqueous H{sup ·} atom chemistry over this temperature range. An important reaction to study is that of the H{sup ·} atom with water itself, because it is a potential source of molecular H{sub 2}. The concentration of H{sub 2} is important to plant coolant chemistry, as H{sub 2} is currently added to suppress oxidative corrosion in CANDU reactors. The reaction of muonium with H{sub 2}O and D{sub 2}O was studied experimentally up to 450 °C, and also via quantum chemical computations to investigate possible isotope effects. Our results suggest that although the H{sup ·} atom abstraction from H{sub 2}O is important at temperatures above 300 °C, the electron-producing channel (H{sup ·} + H{sub 2}O ⇌ H{sub 3}O{sup +} + e{sub aq}{sup -}) is significant at temperatures up to 300 °C, and becomes the dominant reaction channel at lower temperatures.

  17. Modification of Oil Palm Mesocarp Fiber Characteristics Using Superheated Steam Treatment

    Directory of Open Access Journals (Sweden)

    Subbian Karuppuchamy

    2013-07-01

    Full Text Available In this study, oil palm mesocarp fiber (OPMF was treated with superheated steam (SHS in order to modify its characteristics for biocomposite applications. Treatment was conducted at temperatures 190–230 °C for 1, 2 and 3 h. SHS-treated OPMF was evaluated for its chemical composition, thermal stability, morphology and crystallinity. OPMF treated at 230 °C exhibited lower hemicellulose content (9% compared to the untreated OPMF (33%. Improved thermal stability of OPMF was found after the SHS treatment. Moreover, SEM and ICP analyses of SHS-treated OPMF showed that silica bodies were removed from OPMF after the SHS treatment. XRD results exhibited that OPMF crystallinity increased after SHS treatment, indicating tougher fiber properties. Hemicellulose removal makes the fiber surface more hydrophobic, whereby silica removal increases the surface roughness of the fiber. Overall, the results obtained herewith suggested that SHS is an effective treatment method for surface modification and subsequently improving the characteristics of the natural fiber. Most importantly, the use of novel, eco-friendly SHS may contribute to the green and sustainable treatment for surface modification of natural fiber.

  18. Monte Carlo evaluation of the neutron detection efficiency of a superheated drop detector

    Energy Technology Data Exchange (ETDEWEB)

    Gualdrini, G.F. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dipt. Ambiente; D`Errico, F.; Noccioni, P. [Pisa, Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari

    1997-03-01

    Neuron dosimetry has recently gained renewed attention, following concerns on the exposure of crew members on board aircraft, and of workers around the increasing number of high energy accelerators for medical and research purpose. At the same time the new operational qualities for radiation dosimetry introduced by ICRU and the ICRP, aiming at a unified metrological system applicable to all types of radiation exposure, involved the need to update current devices in order to meet new requirements. Superheated Drop (Bubble) Detectors (SDD) offer an alternative approach to neutron radiation protection dosimetry. The SDDs are currently studied within a large collaborative effort involving Yale University. New Haven CT, Pisa (IT) University, the Physikalisch-Technische Bundesanstalt, Braunschweig D, and ENEA (Italian National Agency for new Technologies Energy and the Environment) Centre of Bologna. The detectors were characterised through calibrations with monoenergetic neutron beams and where experimental investigations were inadequate or impossible, such as in the intermediate energy range , parametric Monte Carlo calculations of the response were carried out. This report describes the general characteristic of the SDDs along with the Monte Carlo computations of the energy response and a comparison with the experimental results.

  19. Monte Carlo evaluation of the neutron detection efficiency of a superheated drop detector

    Energy Technology Data Exchange (ETDEWEB)

    Gualdrini, G. F. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dipt. Ambiente; D`Errico, F.; Noccioni, P. [Pisa, Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari

    1997-06-01

    Neutron dosimetry has recently gained renewed attention, following concerns on the exposure of crew members on board aircraft, and of workers around the increasing number of high energy accelerators for medical and research purposes. At the same time the new operational quantities for radiation dosimetry introduced by ICRU and the ICRP, aiming at a unified metrological system applicable to all types of radiation exposure, involved the need to update current devices in order to meet new requirements. Superheated Drop (Bubble) Detectors (SDD) offer an alternative approach to neutron radiation protection dosimetry. The SDDs are currently studied within a large collaborative effort involving Yale University, New Haven CT, the `Universita` degli Studi di Pisa`, the Physikalisch-Technische Bundesanstalt, Braunschweig D. and ENEA (National Agency for New Technology, Energy and the Environment)-C.R., Bologna. The detectors were characterised through calibrations with monoenergetic neutron beams and where experimental investigations were inadequate or impossible, such as in the intermediate energy range, parametric Monte Carlo calculations of the response were carried out. This report describes the general characteristics of the SDDs along with the Monte Carlo computations of the energy response and a comparison with the experimental results.

  20. Kinetics of Texture and Colour Changes in Chicken Sausage during Superheated Steam Cooking

    Directory of Open Access Journals (Sweden)

    Abdulhameed Asmaa A.

    2016-07-01

    Full Text Available The aim of this study was to develop a kinetic model to describe the texture and colour changes of chicken sausage during superheated steam cooking. Chicken sausages were cooked at temperature ranging from 150-200°C with treatment times ranging from 2-6 mins. The texture profile was evaluated in terms of hardness, cohesiveness, gumminess, and chewiness, while the colour parameters were estimated in terms of lightness (L*, redness (a*, yellowness (b*, and total colour difference (∆E. Experimental data showed a gradual reduction in texture parameters as cooking times and temperatures increased. The L* value of the colour showed a linear reduction with cooking condition, while the a*, b*, and ∆E values showed a contrary effects. The decrease in texture parameters and L*-value of colour parameter followed the first-order kinetic model. While, zero-order kinetic model was adapted to fit the a* and b*. The modified first order kinetic showed a good fit for total ∆E. Significant correlations between colour and texture parameters were observed, which showed that a* alone could be used to predict the texture of chicken sausage.