Mathematical modeling of control system for the experimental steam generator

Science.gov (United States)

Podlasek, Szymon; Lalik, Krzysztof; Filipowicz, Mariusz; Sornek, Krzysztof; Kupski, Robert; Raś, Anita

2016-03-01

A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units - quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics) are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

Westinghouse Small Modular Reactor nuclear steam supply system design

Energy Technology Data Exchange (ETDEWEB)

Memmott, M. J.; Harkness, A. W.; Van Wyk, J. [Westinghouse Electric Company LLC, 600 Cranberry Woods Drive, Cranberry Twp. PA 16066 (United States)

2012-07-01

The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the first in a series of four papers which describe the design and functionality of the Westinghouse SMR. Also described in this series are the key drivers influencing the design of the Westinghouse SMR and the unique passive safety features of the Westinghouse SMR. Several critical motivators contributed to the development and integration of the Westinghouse SMR design. These design driving motivators dictated the final configuration of the Westinghouse SMR to varying degrees, depending on the specific features under consideration. These design drivers include safety, economics, AP1000{sup R} reactor expertise and experience, research and development requirements, functionality of systems and components, size of the systems and vessels, simplicity of design, and licensing requirements. The Westinghouse SMR NSSS consists of an integral reactor vessel within a compact containment vessel. The core is located in the bottom of the reactor vessel and is composed of 89 modified Westinghouse 17x17 Robust Fuel Assemblies (RFA). These modified fuel assemblies have an active core length of only 2.4 m (8 ft) long, and the entirety of the core is encompassed by a radial reflector. The Westinghouse SMR core operates on a 24 month fuel cycle. The reactor vessel is approximately 24.4 m (80 ft) long and 3.7 m (12 ft) in diameter in order to facilitate standard rail shipping to the site. The reactor vessel houses hot and cold leg channels to facilitate coolant flow, control rod drive mechanisms (CRDM), instrumentation and cabling, an intermediate flange to separate flow and instrumentation and facilitate simpler refueling, a pressurizer, a straight tube, recirculating steam

The supply of steam from Candu reactors for heavy water production

International Nuclear Information System (INIS)

Robertson, R.F.S.

1975-09-01

By 1980, Canada's energy needs for D 2 O production will be 420 MW of electrical energy and 3600 MW of thermal energy (as steam). The nature of the process demands that this energy supply be exceptionally stable. Today, production plants are located at or close to nuclear electricity generating sites where advantage can be taken of the low cost of both the electricity and steam produced by nuclear reactors. Reliability of energy supply is achieved by dividing the load between the multiple units which comprise the sites. The present and proposed means of energy supply to the production sites at the Bruce Heavy Water Plant in Ontario and the La Prade Heavy Water Plant in Quebec are described. (author)

Mathematical modeling of control system for the experimental steam generator

Directory of Open Access Journals (Sweden)

Podlasek Szymon

2016-01-01

Full Text Available A steam generator is an essential unit of each cogeneration system using steam machines. Currently one of the cheapest ways of the steam generation can be application of old steam generators came from army surplus store. They have relatively simple construction and in case of not so exploited units – quite good general conditions, and functionality of mechanical components. By contrast, electrical components and control systems (mostly based on relay automatics are definitely obsolete. It is not possible to use such units with cooperation of steam bus or with steam engines. In particular, there is no possibility for automatically adjustment of the pressure and the temperature of the generated steam supplying steam engines. Such adjustment is necessary in case of variation of a generator load. The paper is devoted to description of improvement of an exemplary unit together with construction of the measurement-control system based on a PLC. The aim was to enable for communication between the steam generator and controllers of the steam bus and steam engines in order to construction of a complete, fully autonomic and maintenance-free microcogeneration system.

Hybrid district heating system with heat supply from nuclear source

International Nuclear Information System (INIS)

Havelka, Z.; Petrovsky, I.

1987-01-01

Several designs are described of heat supply from large remote power sources (e.g., WWER-1000 nuclear power plants with a 1000 MW turbine) to localities where mainly steam distribution networks have been built but only some or none networks for hot water distribution. The benefits of the designs stem from the fact that they do not require the conversion of the local steam distribution system to a hot water system. They are based on heat supply from the nuclear power plant to the consumer area in hot water of a temperature of 150 degC to 200 degC. Part of the hot water heat will be used for the production of low-pressure steam which will be compressed using heat pumps (steam compressors) to achieve the desired steam distribution network specifications. Water of lower temperature can be used in the hot water network. The hot water feeder forms an automatic pressure safety barrier in heat supply of heating or technological steam from a nuclear installation. (Z.M.). 5 figs., 9 refs

Nuclear steam supply system KLT-40 enhanced safety as independent power supply source. Employment prospects

International Nuclear Information System (INIS)

Polunichev, V.I.; Sayanov, D.G.; Ardabievsky, A.A.

1993-01-01

High quality of KLT-40 nuclear steam supply system (NSSS) providing enhanced safety is attained owing to the development and operation experience of equipments and systems in Soviet nuclear icebreakers. First of all they are the operating nuclear-powered icebreakers open-quotes Arktikaclose quotes, open-quotes Sibirclose quotes, open-quotes Rossiyaclose quotes, open-quotes Sovetsky Soyuzclose quotes, the limited draught icebreakers of joint Soviet-Finnish manufacturing open-quotes Taimyrclose quotes open-quotes Vaigachclose quotes. 30-years trouble-free operation of icebreaker open-quotes Leninclose quotes, the ancestor of nuclear powered fleet, is unprecedented. Operation life of individual equipment items amounts to 107000 hours, that testifies to high reliability and life characteristics of NSSS. Trouble-free operation of the nuclear-powered icebreakers' reactor plants (RPs) exceeded 130 reactor years, that proves high quality of design decisions being underlain in the basis of the KLT-40 NSSS for the lighter-cargo carrier open-quotes Sevmorputclose quotes, which was put into operation into 1988. Besides it testifies to the expediency of KLT-40 NSSS employment as a power source in different power installations. The KLT-40 is a reactor plant with a pwr type reactor. The design is described in detail with diagrams

Steam coal trade: demand, supply and prices to 2020

Energy Technology Data Exchange (ETDEWEB)

1993-04-01

This report on the international seaborne steam coal market was prepared using an electricity generation model developed for each coal-importing country, with the aid of WEFA Energy's power station database. The report contains chapters on: import demand forecasting methodology; orimulsion (environmental considerations and market potential); Scandinavia; North West Europe; British Isles; South West Europe; Eastern Europe; Eastern Mediterranean and North Africa; Asia; Latin America; North America; world steam coal demand summary; trade and price forecasting methodology; base case forecast; shipping rates; import demand; export supply and foreign exchange rates.

Optimum fuel allocation in parallel steam generator systems

International Nuclear Information System (INIS)

Bollettini, U.; Cangioli, E.; Cerri, G.; Rome Univ. 'La Sapienza'; Trento Univ.

1991-01-01

An optimization procedure was developed to allocate fuels into parallel steam generators. The procedure takes into account the level of performance deterioration connected with the loading history (fossil fuel allocation and maintenance) of each steam generator. The optimization objective function is the system hourly cost, overall steam demand being satisfied. Costs are due to fuel and electric power supply and to plant depreciation and maintenance as well. In order to easily updata the state of each steam generator, particular care was put in the general formulation of the steam production function by adopting a special efficiency-load curve description based on a deterioration scaling parameter. The influence of the characteristic time interval length on the optimum operation result is investigated. A special implementation of the method based on minimum cost paths is suggested

ORTAP: a nuclear steam supply system simulation for the dynamic analysis of high temperature gas cooled reactor transients

International Nuclear Information System (INIS)

Cleveland, J.C.; Hedrick, R.A.; Ball, S.J.; Delene, J.G.

1977-01-01

ORTAP was developed to predict the dynamic behavior of the high temperature gas cooled reactor (HTGR) Nuclear Steam Supply System for normal operational transients and postulated accident conditions. It was developed for the Nuclear Regulatory Commission (NRC) as an independent means of obtaining conservative predictions of the transient response of HTGRs over a wide range of conditions. The approach has been to build sufficient detail into the component models so that the coupling between the primary and secondary systems can be accurately represented and so that transients which cover a wide range of conditions can be simulated. System components which are modeled in ORTAP include the reactor core, a typical reheater and steam generator module, a typical helium circulator and circulator turbine and the turbine generator plant. The major plant control systems are also modeled. Normal operational transients which can be analyzed with ORTAP include reactor start-up and shutdown, normal and rapid load changes. Upset transients which can be analyzed with ORTAP include reactor trip, turbine trip and sudden reduction in feedwater flow. ORTAP has also been used to predict plant response to emergency or faulted conditions such as primary system depressurization, loss of primary coolant flow and uncontrolled removal of control poison from the reactor core

Optimization of Temperature Schedule Parameters on Heat Supply in Power-and-Heat Supply Systems

Directory of Open Access Journals (Sweden)

V. A. Sednin

2009-01-01

Full Text Available The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel. 

Power plant and system for accelerating a cross compound turbine in such plant, especially one having an HTGR steam supply

International Nuclear Information System (INIS)

Jaegtnes, K.O.; Braytenbah, A.S.

1977-01-01

An electric power plant having a cross compound steam turbine and a steam source that includes a high temperature gas-cooled nuclear reactor is described. The steam turbine includes high and intermediate-pressure portions which drive a first generating means, and a low-pressure portion which drives a second generating means. The steam source supplies superheat steam to the high-pressure turbine portion, and an associated bypass permits the superheat steam to flow from the source to the exhaust of the high-pressure portion. The intermediate and low-pressure portions use reheat steam; an associated bypass permits reheat steam to flow from the source to the low-pressure exhaust. An auxiliary turbine driven by steam exhausted from the high-pressure portion and its bypass drives a gas blower to propel the coolant gas through the reactor. While the bypass flow of reheat steam is varied to maintain an elevated pressure of reheat steam upon its discharge from the source, both the first and second generating means and their associated turbines are accelerated initially by admitting steam to the intermediate and low-pressure portions. The electrical speed of the second generating means is equalized with that of the first generating means, whereupon the generating means are connected and acceleration proceeds under control of the flow through the high-pressure portion. 29 claims, 2 figures

Simulation of a Nuclear Steam Supply System (NSSS) of a PWR nuclear power plant. Simulacao do sistema nuclear de geracao de vapor de uma central PWR

Energy Technology Data Exchange (ETDEWEB)

Reis Martins Junior, L.L. dos.

1980-01-01

The following work intends to perform the digital simulation, of the Nuclear Steam Supply System (NSSS) of a PWR nuclear power plant for control systems design and analysis purposes. There are mathematical models for the reactor, the steam generator, the pressurizer and for transport lags of the coolant in the primary circuit. Nevertheless no one control system has been considered to permit any user the inclusion in the more convenient way of the desired control systems' models. The characteristics of the system in consideration are fundamentally equal to the ones of Almirante Alvaro Alberto Nuclear Power Plant, Unit I (Angra I) obtained in the Final Safety Analysis Report at Comissao Nacional de Energia Nuclear. (author).

Water supply method to the fuel cell cooling water system; Nenryo denchi reikyakusuikei eno kyusui hoho

Energy Technology Data Exchange (ETDEWEB)

Urata, T. [Tokyo (Japan); Nishida, S. [Tokyo (Japan)

1996-12-17

The conventional fuel cell has long cooling water piping ranging from the fuel cell exit to the steam separator; in addition, the supply water is cooler than the cooling water. When the amount of supply water increases, the temperature of the cooling water is lowered, and the pressure fluctuation in the steam separator becomes larger. This invention relates to the water supply method of opening the supply water valve and supplying water from the supply water system to the cooling water system in accordance with the signal of the level sensor of the steam separator, wherein opening and closing of the supply valve are repeated during water supply. According to the method the pressure drop in every water supply becomes negligibly small; therefore, the pressure fluctuation of the cooling water system can be made small. The interval of the supply water valve from opening to closing is preferably from 3 seconds to 2 minutes. The method is effective when equipment for recovering heat from the cooling water is installed in the downstream pipeline of the fuel cell. 2 figs.

Operating experience of the EBR-II steam generating system

International Nuclear Information System (INIS)

Buschman, H.W.; Penney, W.H.; Quilici, M.D.; Radtke, W.H.

1981-01-01

The Experimental Breeder Reactor II (EBR-II) is a Liquid Metal Fast Breeder Reactor (LMFBR) with integrated power producing capability. Superheated steam is produced by eight natural circulation evaporators, two superheaters, and a conventional steam drum. Steam throttle conditions are 438 C (820 F) and 8.62 MPa (1250 psi). The designs of the evaporators and superheaters are essentially identical; both are counterflow units with low pressure nonradioactive sodium on the shell side. Safety and reliability are maximized by using duplex tubes and tubesheets. The performance of the system has been excellent and essentially trouble free. The operating experience of EBR-II provides confidence that the technology can be applied to commercial LMFBR's for an abundant supply of energy for the future. 5 refs

Steam process supply optimization for Arcelormittal Tubarao consumers; Otimizacao do sistema de fornecimento de vapor de processo para a usina (AMT)

Energy Technology Data Exchange (ETDEWEB)

Loss, Gecimar; Oliveira, Heron Domingues de; Silva, Jose Geraldo Lessa; Beccalli, Marcelo; Calente, Paulo Sergio Boni; Monteiro, Sergio Anderson [Companhia Siderurgica de Tubarao ArcelorMittal, Serra, ES (Brazil)

2010-07-01

The ArcelorMittal Tubarao Energy Production area is compounded by three units: Air Separation Units, Thermal Power Plants and Thermal Recovery Power Plants. The Thermo Power Plants are co-generated units responsible to generate electrical, mechanical (Blast Furnace blower) energy and also provide Steam to complement the facility internal consumption mainly provided by CDQ plant (CDQ - Coke Dry Quenching). Since RH2 (steel treatment process) start up, the steam consumption increased and the Thermal Power Plant contribution raised to attend this new demand. Solutions were needed to guarantee the steam supply by the Power Plant even in low steam header stoppages for maintenance, since the lack of steam caused by shortage in Power Plant steam supply resulting in steel production diminution in this new scenario. (author)

Nuclear applications for steam and hot water supply

International Nuclear Information System (INIS)

1991-07-01

An increase in the heat energy needs underlined by the potential increase in fossil fuel prices, particularly in oil supplies, and by the necessity for an improvement of the environment worldwide, as signalized by the IAEA Member States, prompted the decision to start a programme leading to this report. This document is intended to help to identify the experience of Member States where nuclear power plants or specialized nuclear heat plants are employed or envisaged to be used for distribution of steam or hot water to industrial or residential consumers, covering low and medium temperature ranges. 25 refs, 33 figs, 15 tabs

What is geothermal steam worth?

International Nuclear Information System (INIS)

Thorhallsson, S.; Ragnarsson, A.

1992-01-01

Geothermal steam is obtained from high-temperature boreholes, either directly from the reservoir or by flashing. The value of geothermal steam is similar to that of steam produced in boilers and lies in its ability to do work in heat engines such as turbines and to supply heat for a wide range of uses. In isolated cases the steam can be used as a source of chemicals, for example the production of carbon dioxide. Once the saturated steam has been separated from the water, it can be transported without further treatment to the end user. There are several constraints on its use set by the temperature of the reservoir and the chemical composition of the reservoir fluid. These constraints are described (temperature of steam, scaling in water phase, gas content of steam, well output) as are the methods that have been adopted to utilize this source of energy successfully. Steam can only be transported over relatively short distances (a few km) and thus has to be used close to the source. Examples are given of the pressure drop and sizing of steam mains for pipelines. The path of the steam from the reservoir to the end user is traced and typical cost figures given for each part of the system. The production cost of geothermal steam is estimated and its sensitivity to site-specific conditions discussed. Optimum energy recovery and efficiency is important as is optimizing costs. The paper will treat the steam supply system as a whole, from the reservoir to the end user, and give examples of how the site-specific conditions and system design have an influence on what geothermal steam is worth from the technical and economic points of view

A model of Altio Lazio boiling water reactor using the LEGO code nuclear steam supply system simulation

International Nuclear Information System (INIS)

Garbossa, G.B.; Spelta, S.; Cori, R.; Mosca, R.; Cento, P.

1989-01-01

An extensive effort has been made at the Italian National Electricity Board (ENEL) to construct and validate a LEGO model capable of simulating the operational transients of the Alto Lazio Nuclear Station, a two-twin units site with BWR/6 class reactors, rated at 2894 MWt and with Mark III containment. The desired end-product of this effort is an overall plant model consisting of the Nuclear Steam Supply System model, described in this paper, and the Balance of Plant model, capable of simulating the transient response of Alto Lazio Station. The models utilize the in-house developed LEGO code, which is a modular package oriented to power plant modeling and suitable to perform transient analyses to assist during power plant design, control system design and operating procedure verification. The ability of the NSSS model to predict correctly the plant response is demonstrated through comparison with results calculated by the vendor, using REDY code, and by an in-house RETRAN-02 model

Optimizing the Heat Exchanger Network of a Steam Reforming System

DEFF Research Database (Denmark)

Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

2004-01-01

Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...... stationary numerical system model was used and process integration techniques for optimizing the heat exchanger network for the reforming unit are proposed. Objective is to minimize the system cost. Keywords: Fuel cells; Steam Reforming; Heat Exchanger Network (HEN) Synthesis; MINLP....... gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...

The Steam Coal Market in 2016: the Supply Shock

International Nuclear Information System (INIS)

Cornot-Gandolphe, Sylvie

2017-03-01

Surprising coal markets: while the world coal demand is diminishing, the steam coal price doubled in 2016. After five years of uninterrupted price decline and a sluggish world demand, this strong price hike might appear as paradoxical. This paper explains the principal reasons for this situation. After five consecutive years of decline, international steam coal prices doubled in 2016. The main reason is not an increase in global coal consumption, which has been declining since 2014, including in 2016, but the tightening of supplies in the narrow international coal market. Policy changes in China have played a key role. To limit production over-capacity and halt the decline in domestic coal prices, the Chinese government has mandated a reduction in the number of working days in Chinese mines from 330 to 276. This decision has led to a fall in domestic production. Faced with rising coal demand in summer 2016, and surging domestic coal prices from end of June, China once again turned to the international market to cover its supply needs. It thus became again the world's largest coal importer, outpacing India. The increase in Chinese imports did not prevent Chinese demand from falling for the third consecutive year. On the supply side, after five years of declining prices, the export capacities of the main coal supplying countries have been reduced by mine closures, corporate bankruptcies and investment reductions in the sector. This led to the scissor effect observed in 2016, characterized by a sudden and unexpected increase in Chinese imports combined with a supply squeeze. Coal prices surged in the third quarter of 2016, before starting to decline. They have stabilized since December 2016, albeit at high levels. The decline could continue after winter 2016-17. The Chinese government intends to control the level of domestic coal prices to limit their impact on electricity prices and inflation. It has, therefore, relaxed its control on coal production, which has had

Steam feeding redundancy for turbine-drives of feed pumps at WWER-1000 NPP

International Nuclear Information System (INIS)

Nesterov, Yu.V.; Shmukler, B.I.

1987-01-01

The system of steam supply for feed pump driving turbines (T) at the South Ukrainian Unit 1 according to the centralized redundancy principle is described. T is feeded through the collector of water auxiliary sytem (CWAS) to which steam from the third steam extraction line of turbine is supplied under thenormal regime. Under the reduction of turbine load, live steam from the steam generator is supplied to CWAS through the pressure regulator, possesing 10 s speed of responce. In this case the level reduction in the steam generator makes up 170 mm

Steam turbine installations

International Nuclear Information System (INIS)

Bainbridge, A.

1976-01-01

The object of the arrangement described is to enable raising steam for driving steam turbines in a way suited to operating with liquid metals, such as Na, as heat transfer medium. A preheated water feed, in heat transfer relationship with the liquid metals, is passed through evaporator and superheater stages, and the superheated steam is supplied to the highest pressure stage of the steam turbine arrangement. Steam extracted intermediate the evaporator and superheater stages is employed to provide reheat for the lower pressure stage of the steam turbine. Only a major portion of the preheated water feed may be evaporated and this portion separated and supplied to the superheater stage. The feature of 'steam to steam' reheat avoids a second liquid metal heat transfer and hence represents a simplification. It also reduces the hazard associated with possible steam-liquid metal contact. (U.K.)

Cleaning device for steam units in a nuclear power plant

International Nuclear Information System (INIS)

Sasamuro, Takemi.

1978-01-01

Purpose: To prevent radioactive contamination upon dismantling and inspection of steam units such as a turbine to a building containing such units and the peripheral area. Constitution: A steam generator indirectly heated by steam supplied from steam generating source in a separate system containing no radioactivity is provided to produce cleaning steam. A cleaning steam pipe is connected by way of a stop valve between separation valve of a nuclear power plant steam pipe and a high pressure turbine. Upon cleaning, the separation valve is closed, and steam supplied from the cleaning steam pipe is flown into a condenser. The water thus condensated is returned by way of a feed water heater and a condenser to a water storage tank. (Nakamura, S.)

Heat supply analysis of steam reforming hydrogen production process in conventional and nuclear

International Nuclear Information System (INIS)

Siti Alimah; Djati Hoesen Salimy

2015-01-01

Tile analysis of heat energy supply in the production of hydrogen by natural gas steam reforming process has been done. The aim of the study is to compare the energy supply system of conventional and nuclear heat. Methodology used in this study is an assessment of literature and analysis based on the comparisons. The study shows that the heat sources of fossil fuels (natural gas) is able to provide optimum operating conditions of temperature and pressure of 850-900 °C and 2-3 MPa, as well as the heat transfer is dominated by radiation heat transfer, so that the heat flux that can be achieved on the catalyst tube relatively high (50-80 kW/m"2) and provide high thermal efficiency of about 85 %. While in the system with nuclear energy, due to the demands of safety, process operating at less than optimum conditions of temperature and pressure of 800-850 °C and 4.5 MPa, as well as the heat transfer is dominated by convection heat transfer, so that the heat flux that can be achieved catalyst tube is relatively low (1020 kW/m"2) and it provides a low thermal efficiency of about 50 %. Modifications of reformer and heat utilization can increase the heat flux up to 40 kW/m"2 so that the thermal efficiency can reach 78 %. Nevertheless, the application of nuclear energy to hydrogen production with steam reforming process is able to reduce the burning of fossil fuels which has implications for the potential decrease in the rate of CO2 emissions into the environment. (author)

Analysis and decision document in support of acquisition of steam supply for the Hanford 200 Area

Energy Technology Data Exchange (ETDEWEB)

Brown, D.R.; Daellenbach, K.K.; Hendrickson, P.L.; Kavanaugh, D.C.; Reilly, R.W.; Shankle, D.L.; Smith, S.A.; Weakley, S.A.; Williams, T.A. (Pacific Northwest Lab., Richland, WA (United States)); Grant, T.F. (Battelle Human Affairs Research Center, Seattle, WA (United States))

1992-02-01

The US Department of Energy (DOE) is now evaluating its facility requirements in support of its cleanup mission at Hanford. One of the early findings is that the 200-Area steam plants, constructed in 1943, will not meet future space heating and process needs. Because the 200 Area will serve as the primary area for waste treatment and long-term storage, a reliable steam supply is a critical element of Hanford operations. This Analysis and Decision Document (ADD) is a preliminary review of the steam supply options available to the DOE. The ADD contains a comprehensive evaluation of the two major acquisition options: line-term versus privatization. It addresses the life-cycle costs associated with each alternative, as well as factors such as contracting requirements and the impact of market, safety, security, and regulatory issues. Specifically, this ADD documents current and future steam requirements for the 200 Area, describes alternatives available to DOE for meeting these requirements, and compares the alternatives across a number of decision criteria, including life-cycle cost. DOE has currently limited the ADD evaluation alternatives to replacing central steam plants rather than expanding the study to include alternative heat sources, such as a distributed network of boilers or heat pumps. Thirteen project alternatives were analyzed in the ADD. One of the alternatives was the rehabilitation of the existing 200-East coal-fired facility. The other twelve alternatives are combinations of (1) coal- or gas-fueled plants, (2) steam-only or cogeneration facilities, (3) primary or secondary cogeneration of electricity, and (4) public or private ownership.

Development of a nuclear steam generator system for gas-cooled reactors for application in oil sands extraction

International Nuclear Information System (INIS)

Smith, J.; Hart, R.; Lazic, L.

2009-01-01

Canada has vast energy reserves in the Oil Sands regions of Alberta and Saskatchewan. Present extraction technologies, such as strip mining, where oil deposits are close to the surface, and Steam Assisted Gravity Drainage (SAGD) technologies for deeper deposits consume significant amounts of energy to produce the bitumen and upgraded synthetic crude oil. Studies have been performed to assess the feasibility of using nuclear reactors as primary energy sources to produce, in particular the steam required for the SAGD deeper deposit extraction process. Presently available reactors fall short of meeting the requirements, in two areas: the steam produced in a 'standard' reactor is too low in pressure and temperature for the SAGD process. Requirements can be for steam as high as 12MPa pressure with superheat; and, 'standard' reactors are too large in total output. Ideally, reactors of output in the range of 400 to 500 MWth, in modules are better suited to Oil Sands applications. The above two requirements can be met using gas-cooled reactors. Generally, newer generation gas-cooled reactors have been designed for power generation, using Brayton Cycle gas turbines run directly from the heated reactor coolant (helium). Where secondary steam is required, heat recovery steam generators have been used. In this paper, a steam generating system is described which uses the high temperature helium from the reactor directly for steam generation purposes, with sufficient quantities of steam produced to allow for SAGD steam injection, power generation using a steam turbine-generator, and with potential secondary energy supply for other purposes such as hydrogen production for upgrading, and environmental remediation processes. It is assumed that the reactors will be in one central location, run by a utility type organization, providing process steam and electricity to surrounding Oil Sands projects, so steam produced is at very high pressure (12 MPa), with superheat, in order to

New Industrial Park Energy Supply (NIPES): a method of efficiently supplying energy to a community of industrial users

International Nuclear Information System (INIS)

1984-08-01

The New Industrial Park Energy Supply (NIPES) concept allows the use of coal by small as well as large industrial users. The NIPES concept consists of a system of Energy Supply Stations groups of cogeneration plants) and steam transmission lines that supplies process heat and electricity to multiple existing and/or new users in an industrial park(s) setting. The Energy Supply Stations grow along with the industrial park(s) as new industries are attracted by a reliable reasonably priced energy source. The growth of the Energy Supply Stations over a period of years allows the introduction of new energy sources and technologies as they become established. This report describes the generic NIPES concept and the results of the evaluation of a specific NIPES system for the Lake Charles, Louisiana, area. A ten-year process steam load growth scenario is developed including both new and existing industrial users. During the initial years of the growth scenario, process steam is supplied to the industrial users by several coal-fired plants. Later, as the process steam load develops, a two-unit nuclear plant is integrated into the specific NIPES system. An evaluation is also performed for a NIPES system consisting of all coal-fired plants. The specific NIPES system is compared to: (1) individual user owned oil-fired facilities for existing industrial users; and (2) individual user owned coal-fired facilities for new industrial plants. A financial analysis is performed to determine the total economic advantages associated with the NIPES system: savings in a steam costs for industrial users, potential return on investment for investors

New Industrial Park Energy Supply (NIPES): a method of efficiently supplying energy to a community of industrial users

Energy Technology Data Exchange (ETDEWEB)

1984-08-01

The New Industrial Park Energy Supply (NIPES) concept allows the use of coal by small as well as large industrial users. The NIPES concept consists of a system of Energy Supply Stations groups of cogeneration plants) and steam transmission lines that supplies process heat and electricity to multiple existing and/or new users in an industrial park(s) setting. The Energy Supply Stations grow along with the industrial park(s) as new industries are attracted by a reliable reasonably priced energy source. The growth of the Energy Supply Stations over a period of years allows the introduction of new energy sources and technologies as they become established. This report describes the generic NIPES concept and the results of the evaluation of a specific NIPES system for the Lake Charles, Louisiana, area. A ten-year process steam load growth scenario is developed including both new and existing industrial users. During the initial years of the growth scenario, process steam is supplied to the industrial users by several coal-fired plants. Later, as the process steam load develops, a two-unit nuclear plant is integrated into the specific NIPES system. An evaluation is also performed for a NIPES system consisting of all coal-fired plants. The specific NIPES system is compared to: (1) individual user owned oil-fired facilities for existing industrial users; and (2) individual user owned coal-fired facilities for new industrial plants. A financial analysis is performed to determine the total economic advantages associated with the NIPES system: savings in a steam costs for industrial users, potential return on investment for investors.

Project No. 6 - Replacement of the heating and steam plant

International Nuclear Information System (INIS)

2000-01-01

At present the Ignalina NPP facilities and Visaginas town are supplied with heat and steam from the district heating facility at Ignalina NPP. A back-up system, dating from 1979, supplies heat and steam when the district heating system is under repair or in case of outages of units 1 and 2. The existing back-up system does no longer meet with applicable technical and safety standards. A breakdown of the back-up system might result in the interruption of the supply to Ignalina NPP of heat and steam necessary for a number of processes, including waste management. Reconstruction of the existing boiler houses is not economically viable option, nor recommendable, for safety reasons, as it would mean the temporary closing of the back-up system. Project activities includes the design, construction and commissioning of the proposed facility, including all licensing documentation

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

International Nuclear Information System (INIS)

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

Improving Steam System Performance: A Sourcebook for Industry

Energy Technology Data Exchange (ETDEWEB)

2002-06-01

The sourcebook is a reference for industrial steam system users, outlining opportunities to improve steam system performance. This Sourcebook is designed to provide steam system users with a reference that describes the basic steam system components, outlines opportunities for energy and performance improvements, and discusses the benefits of a systems approach in identifying and implementing these improvement opportunities. The Sourcebook is divided into the following three main sections: Section 1: Steam System Basics--For users unfamiliar with the basics of steam systems, or for users seeking a refresher, a brief discussion of the terms, relationships, and important system design considerations is provided. Users already familiar with industrial steam system operation may want to skip this section. This section describes steam systems using four basic parts: generation, distribution, end use, and recovery. Section 2: Performance Improvement Opportunities--This section discusses important factors that should be considered when industrial facilities seek to improve steam system performance and to lower operating costs. This section also provides an overview of the finance considerations related to steam system improvements. Additionally, this section discusses several resources and tools developed by the U. S. Department of Energy's (DOE) BestPractices Steam Program to identify and assess steam system improvement opportunities. Section 3: Programs, Contacts, and Resources--This section provides a directory of associations and other organizations involved in the steam system marketplace. This section also provides a description of the BestPractices Steam Program, a directory of contacts, and a listing of available resources and tools, such as publications, software, training courses, and videos.

Steam generating system in LMFBR type reactors

International Nuclear Information System (INIS)

Kurosawa, Katsutoshi.

1984-01-01

Purpose: To suppress the thermal shock loads to the structures of reactor system and secondary coolant system, for instance, upon plant trip accompanying turbine trip in the steam generation system of LMFBR type reactors. Constitution: Additional feedwater heater is disposed to the pipeway at the inlet of a steam generator in a steam generation system equipped with a closed loop extended from a steam generator by way of a gas-liquid separator, a turbine and a condensator to the steam generator. The separated water at high temperature and high pressure from a gas-liquid separator is heat exchanged with coolants flowing through the closed loop of the steam generation system in non-contact manner and, thereafter, introduced to a water reservoir tank. This can avoid the water to be fed at low temperature as it is to the steam generator, whereby the thermal shock loads to the structures of the reactor system and the secondary coolant system can be suppressed. (Moriyama, K.)

Development of technologies on innovative-simplified nuclear power plant using high-efficiency steam injectors. (6) Operating characteristics of center water jet type supersonic steam injector

International Nuclear Information System (INIS)

Kawamoto, Yujiro; Abe, Yutaka; Iwaki, Chikako; Narabayashi, Tadashi; Mori, Michitsugu; Ohmori, Shuichi

2004-01-01

One of the most interesting devices for next generation reactor systems aiming at simplified system and improvement of safety and credibility is the steam injector which is a passive pump without large motor or turbo-machinery. One of the applications of the steam injector is the passive water injection system to inject the coolant water into the core. The system can be started up merely by injecting the steam without any outer power supply. Since the steam injector is a simple, compact and passive device for water injection, if the steam injector is applied to the actual reactor, it is expected to make the system simple and to reduce the construction cost. Although non-condensable gases are well known for reducing heat transfer between water and steam, the effect of the non-condensable gas on the condensation of supersonic steam on high-speed water jet has not been cleared. The present paper reports about the experimental apparatus, measurement instrument and experimental results of observing the phenomenon inside the test section supplying water and steam to the test by using both the high-speed camera and the video camera and measuring the temperature and the pressure distribution n the test section. (author)

Future development of large steam turbines

International Nuclear Information System (INIS)

Chevance, A.

1975-01-01

An attempt is made to forecast the future of the large steam turbines till 1985. Three parameters affect the development of large turbines: 1) unit output; and a 2000 to 2500MW output may be scheduled; 2) steam quality: and two steam qualities may be considered: medium pressure saturated or slightly overheated steam (light water, heavy water); light enthalpie drop, high pressure steam, high temperature; high enthalpic drop; and 3) the quality of cooling supply. The largest range to be considered might be: open system cooling for sea-sites; humid tower cooling and dry tower cooling. Bi-fluid cooling cycles should be also mentioned. From the study of these influencing factors, it appears that the constructor, for an output of about 2500MW should have at his disposal the followings: two construction technologies for inlet parts and for high and intermediate pressure parts corresponding to both steam qualities; exhaust sections suitable for the different qualities of cooling supply. The two construction technologies with the two steam qualities already exist and involve no major developments. But, the exhaust section sets the question of rotational speed [fr

Assessing reliability in energy supply systems

International Nuclear Information System (INIS)

McCarthy, Ryan W.; Ogden, Joan M.; Sperling, Daniel

2007-01-01

Reliability has always been a concern in the energy sector, but concerns are escalating as energy demand increases and the political stability of many energy supply regions becomes more questionable. But how does one define and measure reliability? We introduce a method to assess reliability in energy supply systems in terms of adequacy and security. It derives from reliability assessment frameworks developed for the electricity sector, which are extended to include qualitative considerations and to be applicable to new energy systems by incorporating decision-making processes based on expert opinion and multi-attribute utility theory. The method presented here is flexible and can be applied to any energy system. To illustrate its use, we apply the method to two hydrogen pathways: (1) centralized steam reforming of imported liquefied natural gas with pipeline distribution of hydrogen, and (2) on-site electrolysis of water using renewable electricity produced independently from the electricity grid

Dynamic Simulation of the Water-steam System in Once-through Boilers - Sub-critical Power Boiler Case -

Energy Technology Data Exchange (ETDEWEB)

Kim, Seongil; Choi, Sangmin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2017-05-15

The dynamics of a water-steam system in a once-through boiler was simulated based on the physics-based modeling approach, representing the system in response to large load change or scale disturbance simulations. The modeling considered the mass, energy conservation, and momentum equation in the water pipe and the focus was limited to the sub-critical pressure region. An evaporator tube modeling was validated against the reference data. A simplified boiler system consisting of economizer, evaporator, and superheater was constructed to match a 500 MW power boiler. The dynamic response of the system following a disturbance was discussed along with the quantitative response characteristics. The dynamic response of the boiler system was further evaluated by checking the case of an off-design point operation of the feedwater-to-fuel supply ratio. The results re-emphasized the significance of controlling the feedwater-to-fuel supply ratio and additional design requirements of the water-steam separator and spray attemperator.

Dynamic Simulation of the Water-steam System in Once-through Boilers - Sub-critical Power Boiler Case -

International Nuclear Information System (INIS)

Kim, Seongil; Choi, Sangmin

2017-01-01

The dynamics of a water-steam system in a once-through boiler was simulated based on the physics-based modeling approach, representing the system in response to large load change or scale disturbance simulations. The modeling considered the mass, energy conservation, and momentum equation in the water pipe and the focus was limited to the sub-critical pressure region. An evaporator tube modeling was validated against the reference data. A simplified boiler system consisting of economizer, evaporator, and superheater was constructed to match a 500 MW power boiler. The dynamic response of the system following a disturbance was discussed along with the quantitative response characteristics. The dynamic response of the boiler system was further evaluated by checking the case of an off-design point operation of the feedwater-to-fuel supply ratio. The results re-emphasized the significance of controlling the feedwater-to-fuel supply ratio and additional design requirements of the water-steam separator and spray attemperator.

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.

Power plant and system for accelerating a cross compound turbine in such plant, especially one having an HTGR steam supply

International Nuclear Information System (INIS)

Jaegtnes, K.O.; Braytenbah, A.S.

1979-01-01

In accordance with the present invention, a power plant includes a steam source to generate superheat and reheat steam which flows through a turbine-generator and an associated bypass system. A high-pressure and an intermediate-pressure turbine portion drive a first electrical generating means, and a low-pressure turbine portion drives a second electrical generating means. A first flow of superheat steam flows through the high-pressure portion, while a second flow of reheat steam flows through the intermediate and low-pressure portions in succession. Provision is made for bypassing steam around the turbine portions; in particular, one bypass means permits a flow of superheat steam from the steam source to the exhaust of the high-pressure portion, and another bypass means allows reheated steam to pass from the source to the exhaust of the low-pressure portion. The first and second steam flows are governed independently. While one of such flows is varied for purposes of controlling the rotational speed of the first generating means according to a desired speed, the other flow is varied to regulate a power plant variable at its desired level. (author)

Genetic optimization of steam multi-turbines system

International Nuclear Information System (INIS)

Olszewski, Pawel

2014-01-01

Optimization analysis of partially loaded cogeneration, multiple-stages steam turbines system was numerically investigated by using own-developed code (C++). The system can be controlled by following variables: fresh steam temperature, pressure, and flow rates through all stages in steam turbines. Five various strategies, four thermodynamics and one economical, which quantify system operation, were defined and discussed as an optimization functions. Mathematical model of steam turbines calculates steam properties according to the formulation proposed by the International Association for the Properties of Water and Steam. Genetic algorithm GENOCOP was implemented as a solving engine for non–linear problem with handling constrains. Using formulated methodology, example solution for partially loaded system, composed of five steam turbines (30 input variables) with different characteristics, was obtained for five strategies. The genetic algorithm found multiple solutions (various input parameters sets) giving similar overall results. In real application it allows for appropriate scheduling of machine operation that would affect equable time load of every system compounds. Also based on these results three strategies where chosen as the most complex: the first thermodynamic law energy and exergy efficiency maximization and total equivalent energy minimization. These strategies can be successfully used in optimization of real cogeneration applications. - Highlights: • Genetic optimization model for a set of five various steam turbines was presented. • Four various thermodynamic optimization strategies were proposed and discussed. • Operational parameters (steam pressure, temperature, flow) influence was examined. • Genetic algorithm generated optimal solutions giving the best estimators values. • It has been found that similar energy effect can be obtained for various inputs

Numerical investigation of passive heat removal system via steam generator in VVER 1200

International Nuclear Information System (INIS)

Dinh Anh Tuan; Duong Thanh Tung; Tran Chi Thanh; Nguyen Van Thai

2015-01-01

Passive heat removal system (PHRS) via Steam Generator is an important part in VVER design. In case of Design Basic Accidents such as blackout, failure of feed water supply to steam generator or coolant leakage with failure of emergency core cooling at high pressure. PHRS is designed to remove the residual heat from reactor core through steam generator to heat exchanger which is placed outside reactor vessel. In order to evaluate the passive system, a numerical investigation using a CFD code is performed. However, PHRS has complex geometry for using CFD simulation. Thus, RELAP5 is applied to provide the wall heat flux of tube in the heat exchanger tank. The natural convection in the heat exchanger tank is investigated in this report. Numerical results show temperature and velocity distribution in the heat exchanger tank are calculated with different wall heat flux corresponding to various transient conditions. The calculated results contribute to the capacity analysis of passive heat removal system and giving valuable information for safe operation of VVER 1200. (author)

Some Thoughts About Water Analysis in Shipboard Steam Propulsion Systems for Marine Engineering Students.

Science.gov (United States)

Schlenker, Richard M.; And Others

Information is presented about the problems involved in using sea water in the steam propulsion systems of large, modern ships. Discussions supply background chemical information concerning the problems of corrosion, scale buildup, and sludge production. Suggestions are given for ways to maintain a good water treatment program to effectively deal…

ECONOMIC PRINCIPLES FOR SELECTION OF OPTIMUM POWER-SUPPLY SYSTEM DEVELOPMENT IN BELARUS

Directory of Open Access Journals (Sweden)

L. P. Padalko

2008-01-01

Full Text Available The paper considers main directions of the technological development of the Belarusian power-supply system. Comparative analysis of the economic efficiency of thermal power station modernization on the basis of steam- and gas technology, nuclear technology development and simple renovation of the worn-out generating capacities of thermal power stations has been carried out in the paper. Selection of the priority direction pertaining to optimization of industrial structure of the Belarusian power-supply system has been made on the basis of the presented minimum-specific cost criterion. The paper reveals that in the medium-term period the most optimum development of the Belarusian electrical power engineering is a technological  modernization  due to predicted  changes in natural gas and nuclear fuel costs. The modernization presupposes construction of topping plants in addition to the existing steam- and turbine equipment at thermal power stations. 

Steam Generator Inspection Planning Expert System

International Nuclear Information System (INIS)

Rzasa, P.

1987-01-01

Applying Artificial Intelligence technology to steam generator non-destructive examination (NDE) can help identify high risk locations in steam generators and can aid in preparing technical specification compliant eddy current test (ECT) programs. A steam Generator Inspection Planning Expert System has been developed which can assist NDE or utility personnel in planning ECT programs. This system represents and processes its information using an object oriented declarative knowledge base, heuristic rules, and symbolic information processing, three artificial intelligence based techniques incorporated in the design. The output of the system is an automated generation of ECT programs. Used in an outage inspection, this system significantly reduced planning time

Development of a steam generator lancing system

International Nuclear Information System (INIS)

Jeong, Woo-Tae; Kim, Seok-Tae; Hong, Sung-Yull

2006-01-01

It is recommended to clean steam generators of nuclear power plants during plant outages. Under normal operations, sludge is created and constantly accumulates in the steam generators. The constituents of this sludge are different depending on each power plant characteristics. The sludge of the Kori Unit 1 steam generator, for example, was found to be composed of 93% ferrous oxide, 3% carbon and 1% of silica oxide and nickel oxide each. The research to develop a lancing system that would remove sludge deposits from the tubesheet of a steam generator was started in 1998 by the Korea Electric Power Research Institute (KEPRI) of the Korea Electric Power Corporation (KEPCO). The first commercial domestic lancing system in Korea, and KALANS-I Lancing System, was completed in 2000 for Kori Unit 1 for cleaning the tubesheet of its Westinghouse Delta-60 steam generator. Thereafter, the success of the development and site implementation of the KALANS-I lancing system for YGN Units 1 and 2 and Ulchin Units 3 and 4 was also realized in 2004 for sludge removal at those sites. The upper bundle cleaning system for Westinghouse model F steam generators is now under development

Innovative-Simplified Nuclear Power Plant Efficiency Evaluation with High-Efficiency Steam Injector System

International Nuclear Information System (INIS)

Shoji, Goto; Shuichi, Ohmori; Michitsugu, Mori

2006-01-01

It is possible to establish simplified system with reduced space and total equipment weight using high-efficiency Steam Injectors (SI) instead of low-pressure feedwater heaters in Nuclear Power Plant (NPP). The SI works as a heat exchanger through direct contact between feedwater from condensers and extracted steam from turbines. It can get higher pressure than supplied steam pressure. The maintenance and reliability are still higher than the feedwater ones because SI has no movable parts. This paper describes the analysis of the heat balance, plant efficiency and the operation of this Innovative-Simplified NPP with high-efficiency SI. The plant efficiency and operation are compared with the electric power of 1100 MWe-class BWR system and the Innovative-Simplified BWR system with SI. The SI model is adapted into the heat balance simulator with a simplified model. The results show that plant efficiencies of the Innovated-Simplified BWR system are almost equal to original BWR ones. The present research is one of the projects that are carried out by Tokyo Electric Power Company, Toshiba Corporation, and six Universities in Japan, funded from the Institute of Applied Energy (IAE) of Japan as the national public research-funded program. (authors)

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.

Prospects of heat supply from Temelin nuclear power plant

International Nuclear Information System (INIS)

Kuba, V.

1987-01-01

The possibilities are discussed of using the Temelin nuclear power plant for heat supply to a number of localities in the South Bohemian Region, to a distance of up to 34 km. Direct supply of steam and of 150/70 degC or 180/65 degC hot water is envisaged. An alternative solution has also been proposed allowing to supply steam and hot water simultaneously from 180 degC hot water with quantitative regulation. The hot water is made to expand at a pressure of 0.3 to 0.5 MPa and the low-pressure steam is compressed to a pressure of 0.9 to 1.3 MPa. This steam will be supplied to the existing heating system. The possibility was also studied of supplying Prague with heat and 180/65 degC hot water of a thermal output of up to 1,700 MW using a two-pipe heat supply line of 105 to 125 km in length. (B.S.). 2 figs

An expert system for steam generator maintenance

International Nuclear Information System (INIS)

Remond, A.

1988-01-01

The tube bundles in PWR steam generators are, by far, the major source of problems whether they are due to primary and secondary side corrosion mechanisms or to tube vibration-induced wear at tube support locations. Because of differences in SG operating, materials, and fabrication processes, the damage may differ from steam generator to steam generator. MPGV, an expert system for steam generator maintenance uses all steam generator data containing data on materials, fabrication processes, inservice inspection, and water chemistry. It has access to operational data for individual steam generators and contains models of possible degradation mechanisms. The objectives of the system are: · Diagnosing the most probable degradation mechanism or mechanisms by reviewing the entire steam generator history. · Identifying the tubes most exposed to future damage and evaluating the urgency of repair by simulating the probable development of the problem in time. · Establishing the appropriate preventive actions such as repair, inspection or other measures and establishing an action schedule. The system is intended for utilities either for individual plants before each inspection outage or any time an incident occurs or for a set of plants through a central MPGV center. (author)

High-temperature oxidation of Zircaloy in hydrogen-steam mixtures

International Nuclear Information System (INIS)

Chung, H.M.; Thomas, G.R.

1982-09-01

Oxidation rates of Zircaloy-4 cladding tubes have been measured in hydrogen-steam mixtures at 1200 to 1700 0 C. For a given isothermal oxidation temperature, the oxide layer thicknesses have been measured as a function of time, steam supply rate, and hydrogen overpressure. The oxidation rates in the mixtures were compared with similar data obtained in pure steam and helium-steam environments under otherwise identical conditions. The rates in pure steam and helium-steam mixtures were equivalent and comparable to the parabolic rates obtained under steam-saturated conditions and reported in the literature. However, when the helium was replaced with hydrogen of equivalent partial pressure, a significantly smaller oxidation rate was observed. For high steam-supply rates, the oxidation kinetics in a hydrogen-steam mixture were parabolic, but the rate was smaller than for pure steam or helium-steam mixtures. Under otherwise identical conditions, the ratio of the parabolic rate for hydrogen-steam to that for pure steam decreased with increasing temperature and decreasing steam-supply rate

Design and construction of a steam generator with feedback

International Nuclear Information System (INIS)

Camargo, Camila C.; Placco, Guilherme M.; Guimaraes, Lamartine N.F.

2013-01-01

The EARTH project aims to develop technologies to design and build systems that generate electricity in space, using microreactors. One of the activities within the TERRA project aims to build a closed thermal cycle Rankine type in order to test a Tesla turbine type. The objective of this work is to design and build a steam generator with feedback, which should ensure a satisfactory range of steam supply, security system, feedback system and heating system

IMPROVEMENT OF SYSTEMS OF TECHNICAL WATER SUPPLY WITH COOLING TOWERS FOR STEAM POWER PLANTS TECHNICAL AND ECONOMIC INDICATORS PERFECTION. Part 1

Directory of Open Access Journals (Sweden)

Yu. A. Zenovich-Leshkevich-Olpinskiy

2016-01-01

Full Text Available In order to reduce the temperature of cooling water and increase the efficiency of use of power resources the main directions of modernization of systems of technical water supply with cooling towers at steam power plants are presented. The problems of operation of irrigation systems and water distribution systems of cooling towers are reviewed. The design of heat and mass transfer devices, their shortcomings and the impact on the cooling ability of the cooling tower are also under analysis. The use of droplet heat and mass transfer device based on the lattice polypropylene virtually eliminates the shortcomings of the film and droplet-film heat and mass transfer devices of the cooling tower, increasing lifetime, and improving the reliability and efficiency of the operation of the main equipment of thermal power plants. The design of the water distribution devices of cooling towers is also considered. It is noted that the most effective are water-spattering low-pressure nozzles made of polypropylene that provides uniform dispersion of water and are of a high reliability and durability.

Containments for consolidated nuclear steam systems

International Nuclear Information System (INIS)

Jabsen, F.S.

1978-01-01

A containment system for a consolidated nuclear steam system incorporating a nuclear core, steam generator and reactor coolant pumps within a single pressure vessel is described which is designed to provide radiation shielding and pressure suppression. Design details, including those for the dry well and wet well of the containment, are given. (UK)

Moisture separators and reheaters for wet steam turbines

International Nuclear Information System (INIS)

Gibbins, J.

1979-01-01

Moisture separator reheater (M.S.R.) units are now a well established feature of the wet steam cycle as associated with the various types of water cooled reactor. This paper describes the development of M.S.Rs. as supplied by GEC for turbine generators of up to 1200 MW ratings covering the design procedures used and the features required to ensure efficient and reliable operation. In addition to details of the M.S.R. design, the desirable features of the steam supply, venting and drain control systems are also discussed. The recent developments, as provided on current projects, are described. (author)

HTGR power plant hot reheat steam pressure control system

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegtnes, K.O.

1975-01-01

A control system for a high temperature gas cooled reactor (HTGR) power plant is disclosed wherein such plant includes a plurality of steam generators. Dual turbine-generators are connected to the common steam headers, a high pressure element of each turbine receiving steam from the main steam header, and an intermediate-low pressure element of each turbine receiving steam from the hot reheat header. Associated with each high pressure element is a bypass line connected between the main steam header and a cold reheat header, which is commonly connected to the high pressure element exhausts. A control system governs the flow of steam through the first and second bypass lines to provide for a desired minimum steam flow through the steam generator reheater sections at times when the total steam flow through the turbines is less than such minimum, and to regulate the hot reheat header steam pressure to improve control of the auxiliary steam turbines and thereby improve control of the reactor coolant gas flow, particularly following a turbine trip. (U.S.)

Diagnostic system of steam generator, especially molten metal heated steam generator

International Nuclear Information System (INIS)

Matal, O.; Martoch, J.

1986-01-01

A diagnostic system is described and graphically represented consisting of a leak detector, a medium analyzer and sensors placed on the piping connected to the indication sections of both tube plates. The advantage of the designed system consists in the possibility of detecting tube failure immediately on leak formation, especially in generators with duplex tubes. This shortens the period of steam generator shutdown for repair and reduces power losses. The design also allows to make periodical leak tests during planned steam generator shutdowns. (A.K.)

Babcock and Wilcox Canada steam generators past, present and future

Energy Technology Data Exchange (ETDEWEB)

Smith, J.C. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada)

1998-07-01

The steam generators in all of the domestic CANDU Plants, and most of the foreign CANDU plants, were supplied by Babcock and Wilcox Canada, either on their own or in co-operation with local manufacturers. More than 200 steam generators have been supplied. In addition, Babcock and Wilcox Canada has taken the technology which evolved out of the CANDU steam generators and has adapted the technology to supply of replacement steam generators for PWR's. There is enough history and operating experience, plus laboratory experience, to point to the future directions which will be taken in steam generator design. This paper documents the steam generators which have been supplied, the experience in operation and maintenance, what has worked and not worked, and how the design, materials, and operating and maintenance philosophy have evolved. The paper also looks at future requirements in the market, and the continuing research and product development going on at Babcock and Wilcox to address the future steam generator requirements. (author)

Babcock and Wilcox Canada steam generators past, present and future

International Nuclear Information System (INIS)

Smith, J.C.

1998-01-01

The steam generators in all of the domestic CANDU Plants, and most of the foreign CANDU plants, were supplied by Babcock and Wilcox Canada, either on their own or in co-operation with local manufacturers. More than 200 steam generators have been supplied. In addition, Babcock and Wilcox Canada has taken the technology which evolved out of the CANDU steam generators and has adapted the technology to supply of replacement steam generators for PWR's. There is enough history and operating experience, plus laboratory experience, to point to the future directions which will be taken in steam generator design. This paper documents the steam generators which have been supplied, the experience in operation and maintenance, what has worked and not worked, and how the design, materials, and operating and maintenance philosophy have evolved. The paper also looks at future requirements in the market, and the continuing research and product development going on at Babcock and Wilcox to address the future steam generator requirements. (author)

Estimates of the costs of steam derived from nuclear and fossil fuels

International Nuclear Information System (INIS)

Spiewak, I.; Klepper, O.H.

1978-01-01

Process steam from intermediate size and large reactors is cheaper than steam produced in conventional boilers burning coal, or oil at $2.21/GJ($14/barrel in 1976 dollars). Small nuclear and coal-based steam supply systems may be competitive with oil under criteria that consider long-term economic inflation and the detailed financial and tax structure of the energy user

Moisture separator for steam generator level measurement system

International Nuclear Information System (INIS)

Cantineau, B.J.

1987-01-01

A steam generator level measurement system having a reference leg which is kept full of water by a condensation pot, has a liquid/steam separator in the connecting line between the condensation pot and the steam phase in the steam generator to remove excess liquid from the steam externally of the steam generator. This ensures that the connecting line does not become blocked. The separator pot has an expansion chamber which slows down the velocity of the steam/liquid mixture to aid in separation, and a baffle, to avoid liquid flow into the line connected to the condensate pot. Liquid separated is returned to the steam generator below the water level through a drain line. (author)

Industrial steam systems and the energy-water nexus.

Science.gov (United States)

Walker, Michael E; Lv, Zhen; Masanet, Eric

2013-11-19

This paper presents estimates for water consumption and steam generation within U.S. manufacturing industries. These estimates were developed through the integration of detailed, industry-level fuel use and operation data with an engineering-based steam system model. The results indicate that industrial steam systems consume approximately 3780 TBTU/yr (3.98 × 10(9) GJ/yr) to generate an estimated 2.9 trillion lb/yr (1.3 trillion kg/yr) of steam. Since a good portion of this steam is injected directly into plant processes, vented, leaked, or removed via blowdown, roughly 354 MGD of freshwater must be introduced to these systems as makeup. This freshwater consumption rate is approximately 11% of that for the entire U.S. manufacturing sector, or the total residential consumption rate of Los Angeles, the second largest city in the U.S. The majority of this consumption (>94%) can be attributed to the food, paper, petroleum refining, and chemicals industries. The results of the analyses presented herein provide previously unavailable detail on water consumption in U.S. industrial steam systems and highlight opportunities for combined energy and water savings.

Current status and prospects for Kepco's steaming coal demand and supply

International Nuclear Information System (INIS)

Kim, E.W.

1991-01-01

Under the series of Korean Government 5 year economic development plans since 1962, energy consumption in Korea has increased at a rapid pace and industrialization in Korea has been accelerated. As far as coal imports are concerned, coking coal was first imported to Korea in the early 1970s for the first steelworks. Little interest was shown in steaming coal until the early 1970s owing to the cheaper imported oil. People became interested in steaming coal after the first oil crisis in 1973 and import began in 1980 for cement and other industrial uses. In general, electricity demand is increasing far more rapidly than energy consumption. The initial construction of two 560 megawatt power plants using bituminous coal began in 1978 and was completed in 1982. The maiden cargo of bituminous coal for power generation arrived in Korea that year and coal import has been increasing at a rapid rate since then to keep pace with increased consumption. As there are no indigenous bituminous coal resources in Korea and we must depend entirely on overseas coal for our needs to fuel power plants, stable securing of coal is very important. This paper explains the current status and prospects for KEPCOs (Korean Electric Power Corporation) coal demand and supply

Drying system for steam generators, particularly for steam generators of nuclear power stations

International Nuclear Information System (INIS)

Lavalerie, Claude; Borrel, Christian.

1982-01-01

A drying system is described which allows for modular construction and which provides a significant available exchange area in a reduced volume. All the drying elements are identical and are distributed according to a ternay circular symmetry and are placed radially and associated to steam guiding facilities which alternately provide around the axis of revolution an output volume of dry steam from one element and an input volume of wet steam in the following element [fr

Steam Turbine Control Valve Stiction Effect on Power System Stability

International Nuclear Information System (INIS)

Halimi, B.

2010-01-01

One of the most important problems in power system dynamic stability is low frequency oscillations. This kind of oscillation has significant effects on the stability and security of the power system. In some previous papers, a fact was introduced that a steam pressure continuous fluctuation in turbine steam inlet pipeline may lead to a kind of low frequency oscillation of power systems. Generally, in a power generation plant, steam turbine system composes of some main components, i.e. a boiler or steam generator, stop valves, control valves and turbines that are connected by piping. In the conventional system, the turbine system is composed with a lot of stop and control valves. The steam is provided by a boiler or steam generator. In an abnormal case, the stop valve shuts of the steal flow to the turbine. The steam flow to the turbine is regulated by controlling the control valves. The control valves are provided to regulate the flow of steam to the turbine for starting, increasing or decreasing the power, and also maintaining speed control with the turbine governor system. Unfortunately, the control valve has inherent static friction (stiction) nonlinearity characteristics. Industrial surveys indicated that about 20-30% of all control loops oscillate due to valve problem caused by this nonlinear characteristic. In this paper, steam turbine control valve stiction effect on power system oscillation is presented. To analyze the stiction characteristic effect, firstly a model of control valve and its stiction characteristic are derived by using Newton's laws. A complete tandem steam prime mover, including a speed governing system, a four-stage steam turbine, and a shaft with up to for masses is adopted to analyze the performance of the steam turbine. The governor system consists of some important parts, i.e. a proportional controller, speed relay, control valve with its stiction characteristic, and stem lift position of control valve controller. The steam turbine has

Upgraded Steam Generator Lancing System for Uljin NPP no.2

International Nuclear Information System (INIS)

Kim, Seok Tae; Jeong, Woo Tae; Hong, Sung Yull

2005-01-01

KEPRI(Korea Electric Power Research Institute) has developed various types of steam generator lancing systems since 1998. In this paper, we introduce a new lancing system with new improvements from the previous steam generator lancing system for Uljin NPP #2(nuclear power plant) constructed by KEPRI. The previous lancing system is registered as KALANS R -II and was developed for System-80 type steam generators. The previous lancing system was applied to Uljin unit #3 and it lowered radiation exposure of operators in comparison to manually operated lancing systems. And it effectively removed sludge accumulated around kidney bean zone in the Uljin unit #3 steam generators. But the previous lancing system could only clean partially the steam generators of Uljin unit #4. This was because the rail of the previous lancing system interfered with a part of the steam generator. Therefore we developed a new lancing system that can solve the interference problem. This new lancing system was upgraded from the previous lancing system. Also, a new lancing system for System-80 S/G will be introduced in this paper

Evolution of near term PBMR steam and cogeneration applications - HTR2008-58219

International Nuclear Information System (INIS)

Kuhr, R. W.; Hannink, R.; Paul, K.; Kriel, W.; Greyvenstein, R.; Young, R.

2008-01-01

US and international applications for large onsite cogeneration (steam and power) systems are emerging as a near term market for the PBMR. The South African PBMR demonstration project applies a high temperature (900 deg. C) Brayton cycle for high efficiency power generation. In addition, a number of new applications are being investigated using an intermediate temperature range (700-750 deg. C) with a simplified heat supply system design. This intermediate helium delivery temperature supports conventional steam Rankine cycle designs at higher efficiencies than obtained from water type reactor systems. These designs can be adapted for cogeneration of steam, similar to the design of gas turbine cogeneration plants that supply steam and power at many industrial sites. This temperature range allows use of conventional or readily qualifiable materials and equipment, avoiding some cost premiums associated with more difficult operating conditions. As gas prices and CO 2 values increase, the potential value of a small nuclear reactor with advanced safety characteristics increases dramatically. Because of its smaller scale, the 400-500 MWt PBMR offers the economic advantages of onsite thermal integration (steam, hot water and desalination co-production) and of providing onsite power at cost versus at retail industrial rates avoiding transmission and distribution costs. Advanced safety characteristics of the PBMR support the location of plants adjacent to steam users, district energy systems, desalination plants, and other large commercial and industrial facilities. Additional benefits include price stability, long term security of energy supply and substantial CO 2 reductions. Target markets include existing sites using gas fired boilers and cogeneration units, new projects such as refinery and petrochemical expansions, and coal-to-liquids projects where steam and power represent major burdens on fuel use and CO 2 emissions. Lead times associated with the nuclear licensing

Estimation of transient heat flux density during the heat supply of a catalytic wall steam methane reformer

Science.gov (United States)

Settar, Abdelhakim; Abboudi, Saïd; Madani, Brahim; Nebbali, Rachid

2018-02-01

Due to the endothermic nature of the steam methane reforming reaction, the process is often limited by the heat transfer behavior in the reactors. Poor thermal behavior sometimes leads to slow reaction kinetics, which is characterized by the presence of cold spots in the catalytic zones. Within this framework, the present work consists on a numerical investigation, in conjunction with an experimental one, on the one-dimensional heat transfer phenomenon during the heat supply of a catalytic-wall reactor, which is designed for hydrogen production. The studied reactor is inserted in an electric furnace where the heat requirement of the endothermic reaction is supplied by electric heating system. During the heat supply, an unknown heat flux density, received by the reactive flow, is estimated using inverse methods. In the basis of the catalytic-wall reactor model, an experimental setup is engineered in situ to measure the temperature distribution. Then after, the measurements are injected in the numerical heat flux estimation procedure, which is based on the Function Specification Method (FSM). The measured and estimated temperatures are confronted and the heat flux density which crosses the reactor wall is determined.

Reactor system

International Nuclear Information System (INIS)

Miyano, Hiroshi; Narabayashi, Naoshi.

1990-01-01

The represent invention concerns a reactor system with improved water injection means to a pressure vessel of a BWR type reactor. A steam pump is connected to a heat removing system pipeline, a high pressure water injection system pipeline and a low pressure water injection system pipeline for injecting water into the pressure vessel. A pump actuation pipeline is disposed being branched from a main steam pump or a steam relieaf pipeline system, through which steams are supplied to actuate the steam pump and supply cooling water into the pressure vessel thereby cooling the reactor core. The steam pump converts the heat energy into the kinetic energy and elevates the pressure of water to a level higher than the pressure of the steams supplied by way of a pressure-elevating diffuser. Cooling water can be supplied to the pressure vessel by the pressure elevation. This can surely inject cooling water into the pressure vessel upon loss of coolant accident or in a case if reactor scram is necessary, without using an additional power source. (I.N.)

Draining down of a nuclear steam generating system

International Nuclear Information System (INIS)

Jawor, J.C.

1987-01-01

The method is described of draining down contained reactor-coolant water from the inverted vertical U-tubes of a vertical-type steam generator in which the upper, inverted U-shaped ends of the tubes are closed and the lower ends thereof are open. The steam generator is part of a nuclear powered steam generating system wherein the reactor coolant water is normally circulated from and back into the reactor via a loop comprising the steam generator and inlet and outlet conduits connected to the lower end of the steam generator. The method comprises continuously introducing a gas which is inert to the system and which is under pressure above atmospheric pressure into at least one of the downwardly facing open ends of each of the U-tubes from below the tube sheet in which the open ends of the U-tubes are mounted adjacent the lower end of the steam generator, while permitting the water to flow out from the open ends of the U-tubes

Development of technologies on innovative-simplified nuclear power plant using high-efficiency steam injectors (5) operating characteristics of center water jet type supersonic steam injector

International Nuclear Information System (INIS)

Abe, Y.; Kawamoto, Y.; Iwaki, C.; Narabayashi, T.; Mori, M.; Ohmori, S.

2005-01-01

Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. As previous studies of the steam injector, there are studies about formulation of operating characteristic of steam injector and analysis of jet structure in steam injector by Narabayashi etc. And as previous studies of the direct contact condensation, there is the study about the direct contact condensation in steam atmosphere. However the study about the turbulent heat transfer under the great shear stress is not enough investigated. Therefore it is necessary to examine in detail about the operating characteristic of the steam injector. The present paper reports the observation results of the water jet behavior in the super sonic steam injector by using the video camera and the high-speed video camera. And the measuring results of the temperature and the pressure distribution in the steam injector are reported. From observation results by video camera, it is cleared that the water jet is established at the center of the steam injector right after steam supplied and the operation of the steam injector depends on the throat diameter. And from observation results by high-speed video camera, it is supposed that the columned water jet surface is established in the mixing nozzle and the water jet surface movement exists. And from temperature measuring results, it is supposed that the steam temperature at the mixing nozzle is changed between about 80 degree centigrade and about 60 degree centigrade. Then from the pressure measuring results, it is confirmed that the pressure at the diffuser depends on each the throat diameter and

Dual-purpose LWR supplying heat for desalination

International Nuclear Information System (INIS)

Waplington, G.; Fitcher, H.

1977-01-01

A number of desalination processes are at present in various stages of development but distillation is the only serious choice for a large-scale project. The distillation process temperature requirement is low compared with the temperature of steam normally delivered to the turbine in a power generation plant. This gives the possibility for combining the functions of electricity generation with water distillation. The brine heater of the multi-stage flash distillation plant can be supplied with steam after partial expansion through a turbine. Such an arrangement allows the use of a standard nuclear steam supply system and makes fuller use of the energy output than would either single purpose role. The LWR represents a safe, reliable and economic system, and is easily able to provide heat of a quality adequate for the desalination process. (M.S.)

Improving Steam System Performance: A Sourcebook for Industry, Second Edition

Energy Technology Data Exchange (ETDEWEB)

None

2012-02-23

This sourcebook is designed to provide steam system users with a reference that describes the basic steam system components, outlines opportunities for energy and performance improvements, and discusses the benefits of a systems approach in identifying and implementing these improvement opportunities. The sourcebook is divided into three main sections: steam system basics, performance improvement opportunities, and where to find help.

A demonstration experiment of steam-driven, high-pressure melt ejection

International Nuclear Information System (INIS)

Allen, M.D.; Pitch, M.; Nichols, R.T.

1990-08-01

A steam blowdown test was performed at the Surtsey Direct Heating Test Facility to test the steam supply system and burst diaphragm arrangement that will be used in subsequent Surtsey Direct Containment Heating (DCH) experiments. Following successful completion of the steam blowdown test, the HIPS-10S (High-Pressure Melt Streaming) experiment was conducted to demonstrate that the technology to perform steam-driven, high-pressure melt ejection (HPME) experiments has been successfully developed. In addition, the HIPS-10S experiment was used to assess techniques and instrumentation design to create the proper timing of events in HPME experiments. This document discusses the results of this test

Leak detection in Phenix and Super Phenix steam generators

Energy Technology Data Exchange (ETDEWEB)

Cambillard, E [Centre d' Etudes Nucleaires de Saclay, Gif-sur-Yvette (France)

1978-10-01

Water leak detection Phenix and Super Phenix steam generators is based on measurement of the hydrogen produced by the reaction of sodium with water. The hydrogen evolves in the sodium in which the steam generator tubes are completely immersed. Depending on service conditions, however (sodium temperature and flow velocity), the hydrogen may appear in the argon existing above the free levels. This is why, although the Phenix steam generators do not feature free levels, measurement systems were added to measure the hydrogen concentration in the argon in the expansion tanks. Super Phenix steam generators are fitted at their outlet with systems for measuring hydrogen in the sodium, and above their free level with a system for measuring hydrogen in the argon. The measurement systems have nickel tube probes connected to circuits kept under vacuum by an ion pump. The hydrogen partial pressure is measured by a mass spectrometer. Super Phenix measurement systems differ from Phenix systems essentially in the temperature regulation of the sodium reaching the nickel tube probes, and in the centralization of the supply and measurement systems of the ion pumps and mass spectrometers. This paper deals with description, calibration and operating conditions of the hydrogen detection systems in sodium and argon in Phenix and Super Phenix steam generators. (author)

Steam 80 steam generator instrumentation

International Nuclear Information System (INIS)

Carson, W.H.; Harris, H.H.

1980-01-01

This paper describes two special instrumentation packages in an integral economizer (preheater) steam generator of one of the first System 80 plants scheduled to go into commercial operation. The purpose of the instrumentation is to obtain accurate operating information from regions of the secondary side of the steam generator inaccessible to normal plant instrumentation. In addition to verification of the System 80 steam generator design predictions, the data obtained will assist in verification of steam generator thermal/hydraulic computer codes developed for generic use in the industry

Fail-safety of the EBR-II steam generator system

International Nuclear Information System (INIS)

Chopra, P.S.; Stone, C.C.; Hutter, E.; Barney, W.K.; Staker, R.G.

1976-01-01

Fail-safe analyses of the EBR-II steam-generator system show that a postulated non-instantaneous leak of water or steam into sodium, through a duplex tube or a tubesheet, at credible leak rates will not structurally damage the evaporators and superheaters. However, contamination of the system and possible shell wastage by sodium-water reaction products may render the system inoperable for a period exceeding six months. This period would be shortened to three months if the system were modified by adding a remotely operated water dump system, a steam vent system, a secondary sodium superheater relief line, and a tubesheet leak-detection system

Design and performance of BWC replacement steam generators for PWR systems

International Nuclear Information System (INIS)

Klarner, R.; Steinmoeller, F.; Millman, J.; Schneider, W.

1998-01-01

In recent years, Babcock and Wilcox Canada (BWC) has provided a number of PWR Replacement Steam Generators (RSGS) to replace units that had experienced extensive Alloy 600 tube degradation. BWC RSG units are in operation at Northeast Utilities' Millstone Unit 2, Rochester Gas and Electric's Ginna Station, Duke Energy's Catawba Unit 1, McGuire Unit 1 and 2, Florida Power and Light's St. Lucie Unit 1 and Commonwealth Edison's Byron 1 Station. Extensive start-up performance characteristics have been obtained for Millstone 2, Ginna, McGuire 1, and Catawba 1 RSGS. The Millstone 2, Ginna and Catawba 1 RSGs have also undergone extensive inspections following their first cycle of operation. The design and start-up performance characteristics of these RSGs are presented. The BWC Replacement Steam generators were designed to fit the existing envelope of pressure boundary dimensions to ensure licensability and integration into the Nuclear Steam Supply System. The RSGs were provided with a tube bundle of Alloy 690TT tubing, sized to match or exceed the original steam generator (OSG) thermal performance including provision for the reduced thermal conductivity of Alloy 690 relative to Alloy 600. The RSG tube bundle configurations provide a higher circulation design relative to the OSG, and feature corrosion resistant lattice grid and U-bend tube supports which provide effective anti-vibration support. The tube bundle supports accommodate relatively unobstructed flow and allow unrestrained structural interactions during thermal transients. Efficient steam separators assure low moisture carryover as well as high circulation. Performance measurements obtained during start-up verify that the BWC RSGs meet or exceed the specified thermal and moisture carryover performance requirements. RSG water level stability results at nor-mal operation and during plant transients have been excellent. Visual and ECT inspections have confirmed minimal deposition and 100% tube integrity following

Nuclear Power Plant Steam Pipes repairing with Tirant 3R Robot System

International Nuclear Information System (INIS)

Ruiz-Martinez, Jose-Tomas; Soto-Tomas, Marcelo; Curiel-Nieva, Marceliano; Monzo-Blasco, Enrique; Pineda-Rodriguez, Salvador; Vaquer-Perez, Juan-Ignacio

2012-09-01

The metallization arc spray process is based on the projection of molten metal, supplied by means of different stainless alloys wire, over a surface of carbon steel usually, with the object of serving as protection against flow assisted corrosion (FAC), increasing resistance to abrasion and deteriorations. A typical application functions covering the steam pipes inner surface in Coal-fired power station and Nuclear Power Plants. The results of this process are spectacular in terms of protection against flow assisted corrosion and abrasion, but its application has conditioning factors, such as: Severe application conditions for workers. Due to the worker's postural position (usually kneeling) in 32' diameter pipes and working with fireproof clothing and masks with outdoor air supplying, due to fumes, sparks and molten metal particles, radiological contamination, confined space, poor lighting... Coating uniformity. As metallization is a manual process, the carried out measurements show small variations in the thickness of the coating, always within the tolerance limits established by the applicable regulations and Quality Assurance. An increase in the uniformity of the projected coating, increase the resistance and give a better surface protection. For all these reasons, Lainsa has developed the TIRANT 3 R system, a worldwide innovative system, for metallization of steam pipes inner surface. TIRANT 3 R system is tele-operated from outside of the pipe, so that human intervention is reduced to the operations of robot positioning and change of metallization wire. As it is an independent system of the human factor, metallization process performance is significantly increased by reducing rest periods due only to the robot maintenance. Likewise, TIRANT 3 R system permits to increase resulting coating uniformity and thus its resistance, keeping selected parameters constant (forward speed, rotation speed and inner surface distance) depending on required type and

Measure Guideline. Steam System Balancing and Tuning for Multifamily Residential Buildings

Energy Technology Data Exchange (ETDEWEB)

Choi, Jayne [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Ludwig, Peter [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States); Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Chicago, IL (United States)

2013-04-01

This guideline provides building owners, professionals involved in multifamily audits, and contractors insights for improving the balance and tuning of steam systems. It provides readers an overview of one-pipe steam heating systems, guidelines for evaluating steam systems, typical costs and savings, and guidelines for ensuring quality installations. It also directs readers to additional resources for details not included here. Measures for balancing a distribution system that are covered include replacing main line vents and upgrading radiator vents. Also included is a discussion on upgrading boiler controls and the importance of tuning the settings on new or existing boiler controls. The guideline focuses on one-pipe steam systems, though many of the assessment methods can be generalized to two-pipe steam systems.

Facility to separate water and steam

International Nuclear Information System (INIS)

Loesel, G.

1977-01-01

The water/steam mixture from the pressure vessel e.g. of a BWR is separated by means of centrifugal separators untilizing the natural separation of steam. The steam is supplied to a steam drying vessel and the water to a water collecting tank. These vessels may be combined to a common vessel or connected through additional pipes. From the water collecting tank, arranged below the steam dryer, a feedwater pipe runs back to the pressure vessel. By construction out of individual components cleaning, decontamination, and operating control are essentially simplified. (RW) 891 RW [de

Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

Directory of Open Access Journals (Sweden)

Zhihua Ge

2018-01-01

Full Text Available To reduce the exergy loss that is caused by the high-grade extraction steam of traditional heating mode of combined heat and power (CHP generating unit, a high back-pressure cascade heating technology for two jointly constructed large-scale steam turbine power generating units is proposed. The Unit 1 makes full use of the exhaust steam heat from high back-pressure turbine, and the Unit 2 uses the original heating mode of extracting steam condensation, which significantly reduces the flow rate of high-grade extraction steam. The typical 2 × 350 MW supercritical CHP units in northern China were selected as object. The boundary conditions for heating were determined based on the actual climatic conditions and heating demands. A model to analyze the performance of the high back-pressure cascade heating supply units for off-design operating conditions was developed. The load distributions between high back-pressure exhaust steam direct supply and extraction steam heating supply were described under various conditions, based on which, the heating efficiency of the CHP units with the high back-pressure cascade heating system was analyzed. The design heating load and maximum heating supply load were determined as well. The results indicate that the average coal consumption rate during the heating season is 205.46 g/kWh for the design heating load after the retrofit, which is about 51.99 g/kWh lower than that of the traditional heating mode. The coal consumption rate of 199.07 g/kWh can be achieved for the maximum heating load. Significant energy saving and CO2 emission reduction are obtained.

Nuclear power plant steam pipes repairing with Tirant 3 Robot system

Energy Technology Data Exchange (ETDEWEB)

Soto, M.; Curiel, M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Lazaro, F. [Revestimientos Anticorrosivos Industriales, S. L. U., Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Arnaldos, A., E-mail: m.soto@lainsa.co [TITANIA Servicios Tecnologicos SL, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain)

2010-10-15

The metallization arc spray process is based on the projection of molten metal, supplied by means of different stainless alloys wire, over a surface of carbon steel usually, with the object of serving as protection against erosion-corrosion, increasing resistance to abrasion and detrition. A typical application functions covering the steam pipes inner surface in coal-fired power station and nuclear power plants. The results of this process are spectacular in terms of protection against corrosion and abrasion, but its application has conditioning factors, such as: Severe application conditions for workers. Due to the worker's postural position (usually kneeling) in 32 diameter pipes and working with fireproof clothing and masks with outdoor air supplying, due to fumes, sparks and molten metal particles, radiological contamination, confined space, poor lighting, ... Coating uniformity. As metallization is a manual process, the carried out measurements show small variations in the thickness of the coating, always within the tolerance limits established by the applicable regulations and quality assurance. An increase in the uniformity of the projected coating, increase the resistance and give a better surface protection. For all these reasons, Lainsa has developed the Tirant 3 robot, a worldwide innovative system, for metallization of steam pipes inner surface. Tirant 3 robot is tele operated from outside of the pipe, so that human intervention is reduced to the operations of robot positioning and change of metallization wire. As it is an independent system of the human factor, metallization process performance is significantly increased by reducing rest periods due only to the robot maintenance. Likewise, Tirant 3 system permits to increase resulting coating uniformity and thus its resistance, keeping selected parameters constant (forward speed, rotation speed and inner surface distance) depending on required type and thickness of wire. (Author)

Thermodynamics of the silica-steam system

Energy Technology Data Exchange (ETDEWEB)

Krikorian, Oscar H [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1970-05-01

In most nuclear cratering and cavity formation applications, the working fluid in the expanding cavity consists primarily of vaporized silica and steam. The chemical reaction products of silica and steam under these conditions are not known, although it is known that silica is very volatile in the presence of high-pressure steam under certain geologic conditions and in steam turbines. A review is made of work on the silica-steam system in an attempt to determine the vapor species that exist, and to establish the associated thermo-dynamic data. The review indicates that at 600-900 deg K and 1-100 atm steam pressure, Si(OH){sub 4} is the most likely silicon-containing gaseous species. At 600-900 deg. K and 100-1000 atm steam, Si{sub 2}O(OH){sub 6} is believed to predominate, whereas at 1350 deg K and 2000-9000 atm, a mixture of Si(OH){sub 4} and Si{sub 2}O(OH){sub 6} is consistent with the observed volatilities. In work at 1760 deg. K in which silica was reacted either with steam at 0.5 and 1 atm, or with gaseous mixtures of H{sub 2}/H{sub 2}O and O{sub 2}/H{sub 2}O at 1 atm total pressure, only part of the volatility could be accounted for by Si(OH){sub 4}. Hydrogen was found to greatly enhance the volatility of silica, and oxygen to suppress it. The species most likely to explain this behavior is believed to be SiO(OH). A number of other species may also be significant under these conditions. Thermodynamic data have been estimated for all species considered. The Si-OH bond dissociation energy is found to be {approx}117 kcal/mole in both Si(OH){sub 4} and Si{sub 2}O(OH){sub 6}. (author)

Vulnerability of steam generator super-emergency feeding. Super-emergency feedwater system for the Mochovce NPP steam-generators

International Nuclear Information System (INIS)

Hlasova, M.; Jary, A.

1997-01-01

The following major requirements and criteria fulfillment concerned the super-emergency feedwater system (SEFW) system were proposed: to provide sufficient water amount for accident conditions, inclusive seismicity, even during required SEFW system operation for the time period of 72 hours; to analyse ensuring of residual heat removal in case of a station black-out; to state criteria for water supply by the SEFW system into the steam generators (SGs); to simplify the existing connection scheme inclusive decreasing the number of valves, which are in series; to analyse and provide the system protection against a common cause failure, which the SEFW system did not provide in some parts (possibilities of three systems failure due to flooding; vulnerability of all tanks by the operation building fall in case of a seismic event; vulnerability of all tanks due to extreme climatic conditions; vulnerability of all tanks during new seismic loading and consequent mutual endangering; the possibility of three systems failure due to common routing in the vicinity of high; energy media on the +14,7 m floor in the intermediate machinery building and due to inconsistent electrical valves secured power supply systems); to analyse temperature increase impact on the number of uses and lifetime of SGs; to perform a change of SEFW system pipelines routing layout outside the dangerous area of the +14,7 m floor in the intermediate machinery building with high energy media; checking the thanks autonomy. There were performed analyses of selected transient operation modes. The analyses had the following objectives: necessary flowrate of the SEFW in case of the primary side stabilised temperature of 140 C till 72 hours of the process duration; sufficient capacity of one subsystem for the supply of sufficient water amount; sufficient water reserve in the tanks at given conditions; and other. Accident situations were evaluated using an analysis and three characteristic operation modes were

Steam generators and fuel engineering utilizing solid, liquid, gaseous and special fuels

Energy Technology Data Exchange (ETDEWEB)

Thor, G

1983-01-01

Provided were technological specifications and details in the design of brown coal fired steam generators, produced in the German Democratic Republic. These steam generators range in their capacity between 1.6 and more than 1,000 t/h. The appropriate coal feeding systems, water supply and cleaning equipment, coal pulverizers and ash removal units are also manufactured. Various schemes show the design of a 25 to 64 t/h, a 320 t/h and an 815 t/h brown coal steam generator. Specifications are given for series of fuel pulverizers available, for the water circulation system and steam evaporators. The VEB Dampferzeugerbau Berlin also offers steam generators for saliniferous brown coal with a steam capacity up to 125 t/h, steam generators for pulverized black coal with a capacity up to 350 t/h and oil and gas fired generators up to 250 t/h. The company has experience in combustion of biomass (sugar cane waste) with oil in steam generators of more than 100 t/h capacity, and in projecting firing systems for other biofuels including rice, peanut and coconut hulls, wood and bark. Multi-biofuel firing in combination with coal for steam generation is also regarded as possible. (In English)

Implementation and rejection of industrial steam system energy efficiency measures

International Nuclear Information System (INIS)

Therkelsen, Peter; McKane, Aimee

2013-01-01

Steam systems consume approximately one third of energy applied at US industrial facilities. To reduce energy consumption, steam system energy assessments have been conducted on a wide range of industry types over the course of 5 years through the Energy Savings Assessment (ESA) program administered by the US Department of Energy (US DOE). ESA energy assessments result in energy efficiency measure recommendations that are given potential energy and energy cost savings and potential implementation cost values. Saving and cost metrics that measure the impact recommended measures will have at facilities, described as percentages of facility baseline energy and energy cost, are developed from ESA data and used in analyses. Developed savings and cost metrics are examined along with implementation and rejection rates of recommended steam system energy efficiency measures. Based on analyses, implementation of steam system energy efficiency measures is driven primarily by cost metrics: payback period and measure implementation cost as a percentage of facility baseline energy cost (implementation cost percentage). Stated reasons for rejecting recommended measures are primarily based upon economic concerns. Additionally, implementation rates of measures are not only functions of savings and cost metrics, but time as well. - Highlights: ► We examine uptake/rejection of industrial steam system energy efficiency measures. ► We examine metrics that correspond to uptake/rejection of recommended measures. ► We examine barriers hindering steam system energy efficiency measure implementation. ► Uptake/rejection of steam measures is linked to potential cost metrics. ► Increased uptake of measures and uptake of more costly measures increases with time

Fluid distribution network and steam generators and method for nuclear power plant training simulator

International Nuclear Information System (INIS)

Alliston, W.H.; Johnson, S.J.; Mutafelija, B.A.

1975-01-01

A description is given of a training simulator for the real-time dynamic operation of a nuclear power plant which utilizes apparatus that includes control consoles having manual and automatic devices corresponding to simulated plant components and indicating devices for monitoring physical values in the simulated plant. A digital computer configuration is connected to the control consoles to calculate the dynamic real-time simulated operation of the plant in accordance with the simulated plant components to provide output data including data for operating the control console indicating devices. In the method and system for simulating a fluid distribution network of the power plant, such as that which includes, for example, a main steam system which distributes steam from steam generators to high pressure turbine steam reheaters, steam dump valves, and feedwater heaters, the simultaneous solution of linearized non-linear algebraic equations is used to calculate all the flows throughout the simulated system. A plurality of parallel connected steam generators that supply steam to the system are simulated individually, and include the simulation of shrink-swell characteristics

Steam generator auxiliary systems

International Nuclear Information System (INIS)

Heinz, A.

1982-01-01

The author deals with damage and defect types obtaining in auxiliary systems of power plants. These concern water/steam auxiliary systems (feed-water tank, injection-control valves, slide valves) and air/fluegas auxiliary systems (blowers, air preheaters, etc.). Operating errors and associated damage are not dealt with; by contrast, weak spots are pointed out which result from planning and design. Damage types and events are collected in statistics in order to facilitate damage evaluation for arriving at improved design solutions. (HAG) [de

Steam-generator-tube-rupture transients for pressurized-water reactors

International Nuclear Information System (INIS)

Dobranich, D.; Henninger, R.J.; DeMuth, N.S.

1982-01-01

Steam generator tube ruptures with and without concurrent main-steam-line break are investigated for pressurized water reactors supplied by the major US vendors. The goal of these analyses is to provide thermodynamic and flow conditions for the determination of iodine transport to the environment and to provide an evaluation of the adequacy of the plant safety systems and operating procedures for controlling these transients. The automatic safety systems of the plant were found to be adequate for the mitigation of these transients. Emergency injection system flows equilibrated with the leakage flows and prevented core uncovery. Sufficient time was afforded by the plant safety systems for the operators to identify the problem and to take appropriate measures

Development of methane conversion improvement method by recycling of residual methane for steam reforming as a part of R and D of HTGR-hydrogen production system

International Nuclear Information System (INIS)

Inagaki, Yoshiyuki; Haga, Katsuhiro; Aita, Hideki; Sekita, Kenji; Hino, Ryutaro; Koiso, Hiroshi.

1998-01-01

The purpose of the present study is to improve methane conversion for an HTGR-steam reforming system by recycling of residual methane. The residual methane in a product gas after steam reforming was recycled with a gas separator of polyimide membrane. Gas separation characteristics of the separator were investigated experimentally and numerically, and an experimental study on recycling system was carried out. The results showed that the recycling system improves apparent methane conversion, ratio of methane conversion to methane supply from a cylinder, from 20 to 32% compared with those without recycling. (author)

Nuclear power plant steam pipes repairing with TIRANT 3 robot system

International Nuclear Information System (INIS)

Soto Tomas, Marcelo; Curiel Nieva, Marceliano; Monzo Blasco, Enrique; Rodriguez, Salvador Pineda; Vaquer Perez, Juan I.

2011-01-01

A typical application functions covering the steam pipes inner surface in coal-fired power station and nuclear power plants. The results of this process are spectacular in terms of protection against corrosion and abrasion, but its application has conditioning factors, such as: Severe application conditions for workers. Due to the postural position (usually kneeling) in small diameter pipes and working with fireproof clothing and masks with outdoor air supplying, due to fumes, sparks and molten metal particles, radiological contamination, confined space, poor lighting... Coating uniformity. As metallization is a manual process, the carried out measurements show small variations in the thickness of the coating, always within the tolerance limits established by the applicable regulations and quality assurance. For all these reasons, Grupo Dominguis has developed the TIRANT 3 robot, a worldwide innovative system, for metallization of steam pipes inner surface. TIRANT 3 robot is teleoperated from outside of the pipe, so that human intervention is reduced to the operations of robot positioning and change of metallization wire. As it is an independent system of the human factor, metallization process performance is significantly increased by reducing rest periods due only to the robot maintenance. Likewise, TIRANT 3 system permits to increase resulting coating uniformity, and thus its resistance, keeping selected parameters constant depending on required type and thickness of wire. TIRANT 3 system has successfully worked in 2010 during the stops refueling of the Units I and II of Laguna Verde nuclear power plant in Mexico. (author)

The use of engineering features and schematic solutions of propulsion nuclear steam supply systems for floating nuclear power plant design

International Nuclear Information System (INIS)

Achkasov, A.N.; Grechko, G.I.; Pepa, V.N.; Shishkin, V.A.

2000-01-01

In recent years many countries and the international community represented by the IAEA have shown a notable interest in designing small and medium size nuclear power plants intended for electricity and heat generation for remote areas. These power plants can be also used for desalination purposes. As these nuclear plants are planned for use in areas without a well-developed power grid, the design shall account for their transportation to the site in complete preparedness for operation. Since the late 80s, the Research and Development Institute of Power Engineering (RDIPE) has carried out active efforts in designing reactor facilities for floating nuclear power plants. This work relies on the long-term experience of RDIPE engineers in designing the propulsion NSSS. Advantages can be gained from the specific engineering solutions that are already applied in the design of propulsion Nuclear Steam Supply System (NSSS) or from development of new designs based on the proven technologies. Successful implementation of the experience has been made easier owing to rather similar design requirements prescribed to ship-mounted NSSS and floating NPP. The common design targets are, in particular, minimization of mass and dimensions, resistance to such external impacts as rolling, heel and trim, operability in case of running aground or collision with other ships, etc. (author)

Reliability study: steam generation and distribution system, Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Baker, F.E.; Davis, E.L.; Dent, J.T.; Walters, D.E.; West, R.M.

1982-10-01

A reliability study for determining the ability of the Steam Generation and Distribution System to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the X-600 Steam Plant and the steam distribution system. The Steam Generation and Distribution System is in good overall condition, but to maintain this condition, the reliability study team made twelve recommendations. Eight of the recommendations are for repair or replacement of existing equipment and have a total estimated cost of $540,000. The other four recommendations are for additional testing, new procedure implementation, or continued investigations

CASTOR - Advanced System for VVER Steam Generator Inspection

International Nuclear Information System (INIS)

Mateljak, Petar

2014-01-01

From the safety point of view, steam generator is a very important component of a nuclear power plant. Only a thin tube wall prevents leakage of radioactive material from the primary side into the environment. Therefore, it is very important to perform inspections in order to detect pipe damage and apply appropriate corrective actions during outage. Application of the nondestructive examination (NDE) technique, that can locate degradation and measure its size and orientation, is an integral part of nuclear power plant maintenance. The steam generator inspection system is consisted of remotely controlled manipulator, testing instrument and software for data acquisition and analysis. Recently, the inspection systems have evolved to a much higher level of automation, efficiency and reliability resulting in a lower cost and shorter outage time. Electronic components have become smaller and deal with more complex algorithms. These systems are very fast, precise, reliable and easy to handle. The whole inspection, from the planning, examination, data analysis and final report, is now a highly automated process, which makes inspection much easier and more reliable. This paper presents the new generation of INETEC's VVER steam generator inspection system as ultimate solution for steam generator inspection and repair. (author)

Design and performance of BWC replacement steam generators for PWR systems

Energy Technology Data Exchange (ETDEWEB)

Klarner, R.; Steinmoeller, F.; Millman, J.; Schneider, W. [Babcock and Wilcox Canada, Cambridge, Ontario (Canada)

1998-07-01

In recent years, Babcock and Wilcox Canada (BWC) has provided a number of PWR Replacement Steam Generators (RSGS) to replace units that had experienced extensive Alloy 600 tube degradation. BWC RSG units are in operation at Northeast Utilities' Millstone Unit 2, Rochester Gas and Electric's Ginna Station, Duke Energy's Catawba Unit 1, McGuire Unit 1 and 2, Florida Power and Light's St. Lucie Unit 1 and Commonwealth Edison's Byron 1 Station. Extensive start-up performance characteristics have been obtained for Millstone 2, Ginna, McGuire 1, and Catawba 1 RSGS. The Millstone 2, Ginna and Catawba 1 RSGs have also undergone extensive inspections following their first cycle of operation. The design and start-up performance characteristics of these RSGs are presented. The BWC Replacement Steam generators were designed to fit the existing envelope of pressure boundary dimensions to ensure licensability and integration into the Nuclear Steam Supply System. The RSGs were provided with a tube bundle of Alloy 690TT tubing, sized to match or exceed the original steam generator (OSG) thermal performance including provision for the reduced thermal conductivity of Alloy 690 relative to Alloy 600. The RSG tube bundle configurations provide a higher circulation design relative to the OSG, and feature corrosion resistant lattice grid and U-bend tube supports which provide effective anti-vibration support. The tube bundle supports accommodate relatively unobstructed flow and allow unrestrained structural interactions during thermal transients. Efficient steam separators assure low moisture carryover as well as high circulation. Performance measurements obtained during start-up verify that the BWC RSGs meet or exceed the specified thermal and moisture carryover performance requirements. RSG water level stability results at nor-mal operation and during plant transients have been excellent. Visual and ECT inspections have confirmed minimal deposition and 100

Solution of multiple circuits of steam cycle HTR system

International Nuclear Information System (INIS)

Li, Fu; Wang, Dengying; Hao, Chen; Zheng, Yanhua

2014-01-01

In order to analyze the dynamic operation performance and safety characteristics of the steam cycle high temperature gas cooled reactor (HTR) systems, it is necessary to find the solution of the whole HTR systems with all coupled circuits, including the primary circuit, the secondary circuit, and the residual heat removal system (RHRS). Considering that those circuits have their own individual fluidity and characteristics, some existing code packages for independent circuits themselves have been developed, for example THEMRIX and TINTE code for the primary circuit of the pebble bed reactor, BLAST for once through steam generator. To solve the coupled steam cycle HTR systems, a feasible way is to develop coupling method to integrate these independent code packages. This paper presents several coupling methods, e.g. the equivalent component method between the primary circuit and steam generator which reflect the close coupling relationship, the overlapping domain decomposition method between the primary circuit and the passive RHRS which reflects the loose coupling relationship. Through this way, the whole steam cycle HTR system with multiple circuits can be easily and efficiently solved by integration of several existing code packages. Based on this methodology, a code package TINTE–BLAST–RHRS was developed. Using this code package, some operation performance of HTR–PM was analyzed, such as the start-up process of the plant, and the depressurized loss of forced cooling accident when different number of residual heat removal trains is operated

Modular sludge collection system for a nuclear steam generator

International Nuclear Information System (INIS)

Appleman, R.H.; Bein, J.D.; Powasaki, F.S.

1986-01-01

A sludge collection system is described for a vertically oriented nuclear steam generator wherein vapors produced in the steam generator pass through means for separating entrained liquid from the vapor prior to the vapor being discharged from the steam generator. The sludge collection system comprises: an upwardly open chamber for collecting the separated liquid and feedwater entering the steam generator; upwardly open sludge collecting containers positioned within the chamber, wherein each of the containers includes a top rim encompassing an opening leading to the interior of each container; generally flat, perforated covers, each of the covers being positioned over one of the openings such that a gap is formed between the cover and the adjacent top rim; sludge agitating means on at least one of the containers; and sludge removal means on at least one of the containers

Pulsed high-pressure (PHP) drain-down of steam generating system

International Nuclear Information System (INIS)

Petrusek, R.A.

1991-01-01

This patent describes an improved method of draining down contained reactor-coolant water from the inverted vertical U-tubes of at least one vertical-type steam generator in which the upper inverted U-shaped ends of the tubes are closed and the lower ends thereof are open, the steam generator having a channel head at its lower end including a vertical dividing wall defining a primary water inlet side and a primary water outlet side of the generator, the steam generator having chemical volume control system means and residual heat removal system means, and the steam generator being part of a nuclear-powered steam generating system wherein the reactor-coolant water is normally circulated from and back into the reactor via a loop comprising the steam generator and inlet and outlet conduits connected to the lower end of the steam generator, and the reactor being in communication with pressurizer means and comprising the steps of introducing a gas which is inert to the system and which is under pressure above atmospheric pressure into at least one of the downwardly facing open ends of each of the U-tubes from below the tubesheet in which the open ends of the U-tubes are mounted adjacent the lower end of the steam generator while permitting the water to flow out from the open ends of the U-tubes, the improvement in combination therewith for substantially increasing the effectiveness and efficiency of such water removal from the tubes. It includes determining the parameters effecting a first average volumetric rate of removal for a predetermined period of time, infra, of the reactor-coolant water from the inverted vertical U-tubes, the specific unit for the first average volumetric rate expressing properties identical with the properties expressed in a second average volumetric rate maintained in a later mentioned step

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.

Steam producing plant concept of 4S for oil sand extraction

International Nuclear Information System (INIS)

Matsuyama, Shinichiro; Nishiguchi, Youhei; Sakashita, Yoshiaki; Kasuga, Shoji; Kawashima, Masatoshi

2009-01-01

Plant concept of small fast reactor '4S' applying to continuous steam production for recovery of crude oil from oil sands was investigated. Assuming typical steam assisted gravity drainage (SAGD) plant whose production scale is 120,000 barrels per day of a crude oil, concept of nuclear steam supply system consisting of eight reactor modules for steam production and three reactor modules for electric generation of the 4S with a thermal rating of 135 MWt was established without any essential or significant design change from the preceding 4S with a thermal rating of 30 MWt. The 4S, provided for an oil sand extraction, will reduce greenhouse gas emission significantly, and has not much burden for development and licensing and has economic competitiveness. (author)

Design and construction features of steam generators at a nuclear power station

International Nuclear Information System (INIS)

Chakrabarti, A.K.; Gupta, K.N.; Bapat, C.N.; Sharma, V.K.

1996-01-01

The Indian nuclear power programme is based on Pressurised Heavy Water Reactors (PHWRs) using natural uranium as fuel and heavy water as reactor coolant as well as moderator. The nuclear heat is generated in the fuel located in the pressure tubes. Pressurised heavy water in the primary heat transport (PHT) system is circulated through the tubes which picks up the heat from the fuel and transfers it to ordinary water in steam generators (SGs) to produce steam. The steam is used for providing power to the turbine. The steam generator is a critical equipment in the nuclear steam supply system (NSSS) of a nuclear reactor. SG tube surface area constitute about 80% of total primary circuit surface area. A typical value in a 220 MWe reactor is 9000 m 2 which can release considerable amount of corrosion products unless very low corrosion rates are achieved by proper design, material selection and water chemistry control. Design and construction features of SGs are given. 1 tab

System for steam-reactivity measurements on fusion-relevant materials

International Nuclear Information System (INIS)

Anderl, R.A.; Pawelko, R.J.; Oates, M.A.; Smolik, G.R.; McCarthy, K.A.

1996-01-01

This paper describes an experimental system developed to investigate steam-metal reactions important to fusion technology. The system is configured specifically to measure hydrogen generation rates and tritium mobilization rates for irradiated beryllium specimens that are heated and exposed to steam. Results are presented for extensive performance and scoping tests of the system to validate the experimental technique, to determine hydrogen-generation rate detection sensitivity, and to establish appropriate calibration methods. These results include measurements of the hydrogen generation rates for steam interactions with austenitic steel, tungsten and beryllium metal specimens. The results of these scoping tests compare favorably with previous work, and they indicate a significant improvement in hydrogen detection sensitivity over previous approaches. 6 refs., 9 figs., 1 tab

Combined installation of electric and heat supply for climatic conditions of Iraq

Science.gov (United States)

Kaisi, Osama Al; Sidenkov, D. V.

2017-11-01

Electricity, heating and cooling are the three main components that make up the energy consumption base in residential, commercial and public buildings around the world. Demand for energy and fuel costs are constantly growing. Combined cooling, heating and power generation or trigeneration can be a promising solution to such a problem, providing an efficient, reliable, flexible, competitive and less harmful alternative to existing heat and cold supply systems. In this paper, scheme of the tri-generation plant on non-aqueous working substances is considered as an installation of a locally centralized electro-heat and cold supply of a typical residential house in a hot climate. The scheme of the combined installation of electro-heat (cold) supply consisted of the vapor power plant and heat pump system on low-boiling working substance for local consumers under the climatic conditions of Iraq is presented. The possibility of using different working substances in the thermodynamic cycles of these units, which will provide better efficiency of such tri-generation systems is shown. The calculations of steam turbine cycles and heat pump part on the selected working substances are conducted. It is proposed to use heat exchangers of plate type as the main exchangers in the combined processing. The developed method of thermal-hydraulic calculation of heat exchangers implemented in MathCad, which allows to evaluate the efficiency of plants of this type using the ε - NTU method. For the selected working substances of the steam part the optimal temperature of heat supply to the steam generator is determined. The results of thermodynamic and technical-economic analysis of the application of various working substances in the “organic” Rankine cycle of the steam turbine unit and the heat pump system of the heat and cold supply system are presented.

Steam Reformer With Fibrous Catalytic Combustor

Science.gov (United States)

Voecks, Gerald E.

1987-01-01

Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

Steam cleaning device

International Nuclear Information System (INIS)

Karaki, Mikio; Muraoka, Shoichi.

1985-01-01

Purpose: To clean complicated and long objects to be cleaned having a structure like that of nuclear reactor fuel assembly. Constitution: Steams are blown from the bottom of a fuel assembly and soon condensated initially at the bottom of a vertical water tank due to water filled therein. Then, since water in the tank is warmed nearly to the saturation temperature, purified water is supplied from a injection device below to the injection device above the water tank on every device. In this way, since purified water is sprayed successively from below to above and steams are condensated in each of the places, the entire fuel assembly elongated in the vertical direction can be cleaned completely. Water in the reservoir goes upward like the steam flow and is drained together with the eliminated contaminations through an overflow pipe. After the cleaning has been completed, a main steam valve is closed and the drain valve is opened to drain water. (Kawakami, Y.)

Control system for fluid heated steam generator

Science.gov (United States)

Boland, J.F.; Koenig, J.F.

1984-05-29

A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

46 CFR 167.45-1 - Steam, carbon dioxide, and halon fire extinguishing systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Steam, carbon dioxide, and halon fire extinguishing....45-1 Steam, carbon dioxide, and halon fire extinguishing systems. (a) General requirements. (1...-extinguishing system. On such vessels contracted for prior to January 1, 1962, a steam smothering system may be...

A pilot-scale steam autoclave system for treating municipal solid waste for recovery of renewable organic content: Operational results and energy usage.

Science.gov (United States)

Holtman, Kevin M; Bozzi, David V; Franqui-Villanueva, Diana; Offeman, Richard D; Orts, William J

2016-05-01

A pilot-scale (1800 kg per batch capacity) autoclave used in this study reduces municipal solid waste to a debris contaminated pulp product that is efficiently separated into its renewable organic content and non-renewable organic content fractions using a rotary trommel screen. The renewable organic content can be recovered at nearly 90% efficiency and the trommel rejects are also much easier to sort for recovery. This study provides the evaluation of autoclave operation, including mass and energy balances for the purpose of integration into organic diversion systems. Several methods of cooking municipal solid waste were explored from indirect oil heating only, a combination of oil and direct steam during the same cooking cycle, and steam only. Gross energy requirements averaged 1290 kJ kg(-1) material in vessel, including the weight of free water and steam added during heating. On average, steam recovery can recoup 43% of the water added and 30% of the energy, supplying on average 40% of steam requirements for the next cook. Steam recycle from one vessel to the next can reduce gross energy requirements to an average of 790 kJ kg(-1). © The Author(s) 2016.

Technical evaluation report on the monitoring of electric power to the reactor-protection system for the Brunswick Steam Electric Plant, Units 1 and 2

International Nuclear Information System (INIS)

Selan, J.C.

1982-01-01

This report documents the technical evaluation of the monitoring of electric power to the reactor protection system (RPS) at the Brunswick Steam Electric Plant, Units 1 and 2. The evaluation is to determine if the proposed design modification will protect the RPS from abnormal voltage and frequency conditions which could be supplied from the power supplies and will meet certain requirements set forth by the Nuclear Regulatory Commission. The proposed design modifications with time delays verified by GE, will protect the RPS from sustained abnormal voltage and frequency conditions from the supplying sources

District heating and cooling systems for communities through power-plant retrofit and distribution network. Volume 2. Tasks 1-3. Final report. [Downtown Toledo steam system

Energy Technology Data Exchange (ETDEWEB)

Watt, J.R.; Sommerfield, G.A.

1979-08-01

Each of the tasks is described separately: Task 1 - Demonstration Team; Task 2 - Identify Thermal Energy Source(s) and Potential Service Area(s); and Task 3 - Energy Market Analysis. The purpose of the project is to establish and implement measures in the downtown Toledo steam system for conserving scarce fuel supplies through cogeneration, by retrofit of existing base- or intermediate-loaded electric-generating plants to provide for central heating and cooling systems, with the ultimate purpose of applying the results to other communities. For Task 1, Toledo Edison Company has organized a Demonstration Team (Battelle Columbus Laboratories; Stone and Webster; Ohio Dept. of Energy; Public Utilities Commission of Ohio; Toledo Metropolitan Area Council of Governments; and Toledo Edison) that it hopes has the expertise to evaluate the technical, legal, economic, and marketing issues related to the utilization of by-product heat from power generation to supply district heating and cooling services. Task 2 gives a complete technical description of the candidate plant(s), its thermodynamic cycle, role in load dispatch, ownership, and location. It is concluded that the Toledo steam distribution system can be the starting point for developing a new district-heating system to serve an expanding market. Battelle is a member of the team employed as a subcontractor to complete the energy market analysis. The work is summarized in Task 3. (MCW)

Steam Digest 2002

Energy Technology Data Exchange (ETDEWEB)

2003-11-01

Steam Digest 2002 is a collection of articles published in the last year on steam system efficiency. DOE directly or indirectly facilitated the publication of the articles through it's BestPractices Steam effort. Steam Digest 2002 provides a variety of operational, design, marketing, and program and program assessment observations. Plant managers, engineers, and other plant operations personnel can refer to the information to improve industrial steam system management, efficiency, and performance.

Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

International Nuclear Information System (INIS)

Pappx, L.

1994-01-01

After modification of Dukovany NPP steam generator feedwater system, the increased concentration of minerals was measured in the cold leg of modified steam generator. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators, has focused this attention on the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of flow distribution in the secondary side of SG was developed. (Author)

Time program using in automatization of steam turbines start-up

International Nuclear Information System (INIS)

Lejzerovich, A.Sh.; Melamed, A.D.

Examples and arguments for developing time programs of changing basic parameters of automated start-up of TPP and NPP high-power steam turbines are considered. Basic parameters subject to controlled changing at automatization of turbine start-up are rotation frequency, loading and temperature of steam supplied to the turbine. Principle facility schemes of program regulation of steam temperature at the start-up are presented. The facility scheme of loading the NPP wet steam turbine is given. The principles of developing time programs, of changing basic parameters of automated start-up enable realizing transient processes close to theoretically optimum processes at arbitrary prestart-up state of the turbine by means of rather simple autatic facilities. In particular, for automated temperature increase of steam supplied to the turbine of TES power units and AES turbine loading, it is advisable to use programs in the form of linear dependence of velocity of changing the controlled parameter on the given value, the initial level, from which the parameter increase with a regulated velocity is realized, is given in the form of analogue dependence on the turbine prestart-up state. The programs described and the schemes of their realization have been approved at the automatization of 300 MW power unit starts up with the K-300-240 turbine and K-220-44 turbine as well as used when creating control system for turbines of 500 MW and higher for designed TPP and NPP power units

Parametric Optimization of Biomass Steam-and-Gas Plant

Directory of Open Access Journals (Sweden)

V. Sednin

2013-01-01

Full Text Available The paper contains a parametric analysis of the simplest scheme of a steam-and gas plant for the conditions required for biomass burning. It has been shown that application of gas-turbine and steam-and-gas plants can significantly exceed an efficiency of steam-power supply units which are used at the present moment. Optimum thermo-dynamical conditions for application of steam-and gas plants with the purpose to burn biomass require new technological solutions in the field of heat-exchange equipment designs.

Econometric simulation model of the US market for steam coal

Energy Technology Data Exchange (ETDEWEB)

Labys, W C; Paik, S; Liebenthal, A M

1979-01-01

An econometric investigation of the historical structure of the U.S. market for steam coal was made to forecast demand, supply, inventory, and price behavior. The structure of the steam coal market is examined and a corresponding theoretical model developed. Consideration is given to alternative simulation models based on various combinations of hypotheses about demand and supply. Results from the models are presented and interpreted. 19 references.

CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

International Nuclear Information System (INIS)

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb; Jacqueline G. Broder

2001-01-01

The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates have been completed and issued for review. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter of 2000. Initial pilot facility shakedown was completed during the fourth quarter. After some unavoidable delays, a suitable representative supply of municipal solid waste (MSW) feed material was procured. During this quarter (first quarter of 2001), shredding of the feed material was completed and final feed conditioning was completed. Pilot facility hydrolysis production was completed to produce lignin for co-fire testing. Pilot facility modifications continued to improve facility operations and performance during the first quarter of 2001. Samples of the co-fire fuel material were sent to the co-fire facility for evaluation. The TVA-Colbert facility has neared completion of the task to evaluate the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system have been completed and a cost estimate for steam supply system is being developed

Evaluation of measures for greenhouse gas emissions reduction in energy supply sector

International Nuclear Information System (INIS)

Khristov, Kh.; Todorova, S.; Vasilev, Kh.; Simeonova, K.

1996-01-01

This study performed by the Energoproekt Company, Sofia (BG) is aimed at estimating the economic costs of CO 2 emissions reduction in the electricity supply system for the period 2000-2020. The specific capital investment and cost price of the following technical options have been compared: reduction of electricity and heat loss; gas and steam cycle power plants; micro hydro potential; renewable sources; extension of nuclear power installations; gas steam turbine equipment; combined cycle power plants. The evaluation is made according to requirements of a baseline scenario - to develop an import-independent energy supply policy and an economic growth without sharp structural changes. A 25-year-operation of a hypothetical energy supply system is modelled by the ENPEP code (ANL, US). The three least-cost options identified are: power loss reduction; gas and steam cycle PPs and hydroelectric objects. An optimal combination of measures, so called ' aggregated scenario' is proposed. It would allow for CO 2 reduction by 23,7 mill tons and prime cost reduction by $19,83 per ton reduced emissions. 3 refs., 2 tabs

Research on simulation of supercritical steam turbine system in large thermal power station

Science.gov (United States)

Zhou, Qiongyang

2018-04-01

In order to improve the stability and safety of supercritical steam turbine system operation in large thermal power station, the body of the steam turbine is modeled in this paper. And in accordance with the hierarchical modeling idea, the steam turbine body model, condensing system model, deaeration system model and regenerative system model are combined to build a simulation model of steam turbine system according to the connection relationship of each subsystem of steam turbine. Finally, the correctness of the model is verified by design and operation data of the 600MW supercritical unit. The results show that the maximum simulation error of the model is 2.15%, which meets the requirements of the engineering. This research provides a platform for the research on the variable operating conditions of the turbine system, and lays a foundation for the construction of the whole plant model of the thermal power plant.

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (12) Evaluations of Spatial Distributions of Flow and Heat Transfer in Steam Injector

International Nuclear Information System (INIS)

Yutaka Abe; Yujiro Kawamoto; Chikako Iwaki; Tadashi Narabayashi; Michitsugu Mori; Shuichi Ohmori

2006-01-01

Next-generation nuclear reactor systems have been under development aiming at simplified system and improvement of safety and credibility. One of the innovative technologies is the supersonic steam injector, which has been investigated as one of the most important component of the next-generation nuclear reactor. The steam injector has functions of a passive pump without large motor or turbo-machinery and a high efficiency heat exchanger. The performances of the supersonic steam injector as a pump and a heat exchanger are dependent on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. In previous studies of the steam injector, there are studies about the operating characteristics of steam injector and about the direct contact condensation between static water pool and steam in atmosphere. However, there is a little study about the turbulent heat transfer and flow behavior under the great shear stress. In order to examine the heat transfer and flow behavior in supersonic steam injector, it is necessary to measure the spatial temperature distribution and velocity in detail. The present study, visible transparent supersonic steam injector is used to obtain the axial pressure distributions in the supersonic steam injector, as well as high speed visual observation of water jet and steam interface. The experiments are conducted with and without non-condensable gas. The experimental results of the interfacial flow behavior between steam and water jet are obtained. It is experimentally clarified that an entrainment exists on the water jet surface. It is also clarified that discharge pressure is depended on the steam supply pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat flux is estimated about 19 MW/m 2 without non-condensable gas condition in steam. (authors)

Pure intelligent monitoring system for steam economizer trips

Directory of Open Access Journals (Sweden)

Basim Ismail Firas

2017-01-01

Full Text Available Steam economizer represents one of the main equipment in the power plant. Some steam economizer's behavior lead to failure and shutdown in the entire power plant. This will lead to increase in operating and maintenance cost. By detecting the cause in the early stages maintain normal and safe operational conditions of power plant. However, these methodologies are hard to be achieved due to certain boundaries such as system learning ability and the weakness of the system beyond its domain of expertise. The best solution for these problems, an intelligent modeling system specialized in steam economizer trips have been proposed and coded within MATLAB environment to be as a potential solution to insure a fault detection and diagnosis system (FDD. An integrated plant data preparation framework for 10 trips was studied as framework variables. The most influential operational variables have been trained and validated by adopting Artificial Neural Network (ANN. The Extreme Learning Machine (ELM neural network methodology has been proposed as a major computational intelligent tool in the system. It is shown that ANN can be implemented for monitoring any process faults in thermal power plants. Better speed of learning algorithms by using the Extreme Learning Machine has been approved as well.

Supercritical Water Nuclear Steam Supply System: Innovations In Materials, Neutronics and Thermal-Hydraulics

International Nuclear Information System (INIS)

Anderson, Mark; Corradini, M.L.; Sridharan, K.; Wilson, P.; Cho, D.; Kim, T.K.; Lomperski, S.

2004-01-01

In the 1990's supercritical light-water reactors were considered in conceptual designs. A nuclear reactor cooled by supercritical waster would have a much higher thermal efficiency with a once-through direct power cycle, and could be based on standardized water reactor components (light water or heavy water). The theoretical efficiency could be improved by more than 33% over that of other water reactors and could be simplified with higher reliability; e.g., a boiling water reactor without steam separators or dryers

On synthesis and optimization of steam system networks. 3. Pressure drop consideration

CSIR Research Space (South Africa)

Price, T

2010-08-01

Full Text Available Heat exchanger networks in steam systems are traditionally designed to operate in parallel. Coetzee and Majozi (Ind. Eng. Chem. Res. 2008, 47, 4405-4413) found that by reusing steam condensate within the network the steam flow rate could be reduced...

Design and construction of a steam generator with feedback; Projeto e construcao de um gerador de vapor com realimentacao

Energy Technology Data Exchange (ETDEWEB)

Camargo, Camila C., E-mail: camilacamargo@outlook.com [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Placco, Guilherme M., E-mail: placco@ieav.cta.br [Instituto de Tecnologia Aeronautica (ITA/CTA), Sao Jose dos Campos, SP (Brazil); Guimaraes, Lamartine N.F., E-mail: guimarae@ieav.cta.br [Instituto de Estudos Avancado (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Departamento ENU

2013-07-01

The EARTH project aims to develop technologies to design and build systems that generate electricity in space, using microreactors. One of the activities within the TERRA project aims to build a closed thermal cycle Rankine type in order to test a Tesla turbine type. The objective of this work is to design and build a steam generator with feedback, which should ensure a satisfactory range of steam supply, security system, feedback system and heating system.

Implementation and Rejection of Industrial Steam System Energy Efficiency Measures

Energy Technology Data Exchange (ETDEWEB)

Therkelesen, Peter [Environmental Energy Technologies Division Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); McKane, Aimee [Environmental Energy Technologies Division Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

2013-05-01

Steam systems consume approximately one third of energy applied at U.S. industrial facilities. To reduce energy consumption, steam system energy assessments have been conducted on a wide range of industry types over the course of five years through the Energy Savings Assessment (ESA) program administered by the U.S. Department of Energy (U.S. DOE). ESA energy assessments result in energy efficiency measure recommendations that are given potential energy and energy cost savings and potential implementation cost values. Saving and cost metrics that measure the impact recommended measures will have at facilities, described as percentages of facility baseline energy and energy cost, are developed from ESA data and used in analyses. Developed savings and cost metrics are examined along with implementation and rejection rates of recommended steam system energy efficiency measures. Based on analyses, implementation of steam system energy efficiency measures is driven primarily by cost metrics: payback period and measure implementation cost as a percentage of facility baseline energy cost (implementation cost percentage). Stated reasons for rejecting recommended measures are primarily based upon economic concerns. Additionally, implementation rates of measures are not only functions of savings and cost metrics, but time as well.

Integrated steam generation process and system for enhanced oil recovery

Energy Technology Data Exchange (ETDEWEB)

Betzer-Zilevitch, M. [Ex-Tar Technologies Inc., Calgary, AB (Canada)

2010-07-01

A method of producing steam for the extraction of heavy bitumens was presented. The direct contact steam generation (DCSG) method is used for the direct heat transfer between combustion gas and contaminated liquid phase water to generate steam. This paper presented details of experimental and field studies conducted to demonstrate the DCSG. Results of the study demonstrated that pressure and temperature are positively correlated. As pressure increases, the flow rate of the discharged mass decreases and the steam ratio decreases. As pressure increases, the condensate and distillate flow rates increases while water vapor losses in the non-condensable gases decrease. The study indicated that for a 10 bar pressurized system producing 9.6 mt per hour of 10,000 kpa steam and 9.6 mt per hour of distillate BFW, 70 percent of the combustion energy should be recovered to generate 10,000 kpa pressure steam for EOR. Combustion energy requirements were found to decrease when pressure decreases. 11 refs., 5 tabs., 8 figs.

Automatic system for redistributing feedwater in a steam generator of a nuclear power plant

International Nuclear Information System (INIS)

Fuoto, J.S.; Crotzer, M.E.; Lang, G.E.

1980-01-01

A system is described for automatically redistributing a steam generator secondary tube system after a burst in the secondary tubing. This applies to a given steam generator in a system having several steam generators partially sharing a common tube system, and employs a pressure control generating an electrical signal which is compared with given values [fr

Studying the processes of sodium-water interaction in the BOR-60 reactor micromodule steam generator

International Nuclear Information System (INIS)

Tsykanov, V.A.; Antipin, G.K.; Borisov, V.V.

1981-01-01

Main results of experimental studies of emergency regimes of micromodule steam generator (MSG) at small and big leaks of water into sodium, realized using the 30 MW MSG, operating in the BOR-o0 reactor, are considered. The aims of the study are as follows: the modelling of macroleak in ''Nadja'' steam generator for the BN-350 reactor; testing the conceptions of alarm signalling and MSG protection; testing under real conditions of new perspective systems of leak detection; gaining the experimence and development of the ways to eliminate the consequences of accident caused by big water leak into sodium; accumulation of knowledge on restoration of MSG operating ability after accident; experimental test of calculational techniques for big leak accidents to use them in future for calculational studies of similar situations at other reactors equipped with sodium-water steam generators; refinement of characteristics of hydrodynamic and thermal effects interaction zone for big leak in real circuit during the plant operation. A series of experiments with the imitation of water leak into sodium by means of argon and steam supply through injection devices, located before the steam superheater module of one of the sections and between evaporator module of the same section, is conducted. The range of steam flow rate is 0.02-0.45 g/s. Duration of steam supply is 100-400 s. A conclusion is made that the results obtained can be used for steam generator of the BN-350 reactor [ru

Methods of increasing thermal efficiency of steam and gas turbine plants

Science.gov (United States)

Vasserman, A. A.; Shutenko, M. A.

2017-11-01

Three new methods of increasing efficiency of turbine power plants are described. Increasing average temperature of heat supply in steam turbine plant by mixing steam after overheaters with products of combustion of natural gas in the oxygen. Development of this idea consists in maintaining steam temperature on the major part of expansion in the turbine at level, close to initial temperature. Increasing efficiency of gas turbine plant by way of regenerative heating of the air by gas after its expansion in high pressure turbine and before expansion in the low pressure turbine. Due to this temperature of air, entering combustion chamber, is increased and average temperature of heat supply is consequently increased. At the same time average temperature of heat removal is decreased. Increasing efficiency of combined cycle power plant by avoiding of heat transfer from gas to wet steam and transferring heat from gas to water and superheated steam only. Steam will be generated by multi stage throttling of the water from supercritical pressure and temperature close to critical, to the pressure slightly higher than condensation pressure. Throttling of the water and separation of the wet steam on saturated water and steam does not require complicated technical devices.

Determining the potential volume of industrial process steam to be generated in nuclear facilities

International Nuclear Information System (INIS)

Jobsky, T.

1990-01-01

The present study serves to determine the market potential of nuclear energy for industrial process steam supply according to branches and sites in the Federal Republic of Germany (excluding the new East German Laender). On the nuclear plant side two HTR reference plants with different unit powers of 200 MWth (HTR-Modul) and 100 MWth are investigated. An essential result in analysing the nuclear market potential is the finding that the number of potential users and sites will triple if smaller unit sizes were introduced. This corresponds to an increase in nuclear plant potential from 28 units of 200 MWth each to 91 units of 100 MWth on the assumptions made in this study. A comparison of economic efficiency between fossil-fired power production plants and the HTR-Modul shows the competitiveness of nuclear process steam and electricity production in the base load range. A single-site evaluation for the centres of energy demand competes conceptually with a combined heat supply by nuclear long-distance energy. This integrated supply concept makes it possible to supply considerably more industrial companies with process steam while reducing the number of sites, since the heat requirements of smaller sites can also be covered by the integrated system. (orig.) [de

Soviet steam generator technology: fossil fuel and nuclear power plants

International Nuclear Information System (INIS)

Rosengaus, J.

1987-01-01

In the Soviet Union, particular operational requirements, coupled with a centralized planning system adopted in the 1920s, have led to a current technology which differs in significant ways from its counterparts elsewhere in the would and particularly in the United States. However, the monograph has a broader value in that it traces the development of steam generators in response to the industrial requirements of a major nation dealing with the global energy situation. Specifically, it shows how Soviet steam generator technology evolved as a result of changing industrial requirements, fuel availability, and national fuel utilization policy. The monograph begins with a brief technical introduction focusing on steam-turbine power plants, and includes a discussion of the Soviet Union's regional power supply (GRES) networks and heat and power plant (TETs) systems. TETs may be described as large central co-generating stations which, in addition to electricity, provide heat in the form of steam and hot water. Plants of this type are a common feature of the USSR today. The adoption of these cogeneration units as a matter of national policy has had a central influence on Soviet steam generator technology which can be traced throughout the monograph. The six chapters contain: a short history of steam generators in the USSR; steam generator design and manufacture in the USSR; boiler and furnace assemblies for fossil fuel-fired power stations; auxiliary components; steam generators in nuclear power plants; and the current status of the Soviet steam generator industry. Chapters have been abstracted separately. A glossary is included containing abbreviations and acronyms of USSR organizations. 26 references

Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

Energy Technology Data Exchange (ETDEWEB)

Papp, L. [Inst. of Material Engineering, Ostrava (Switzerland)

1995-12-31

After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed.

Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

Energy Technology Data Exchange (ETDEWEB)

Papp, L [Inst. of Material Engineering, Ostrava (Switzerland)

1996-12-31

After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed.

Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

International Nuclear Information System (INIS)

Papp, L.

1995-01-01

After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed

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.

Replacement of steam generators at arkansas nuclear one, unit-2 (ano-2)

International Nuclear Information System (INIS)

Wilson, R.M.; Buford, A.

2001-01-01

The Arkansas Nuclear One, Unit-2 steam generators, originally supplied by Combustion Engineering, began commercial operation in 1980 producing a gross electrical output of 958 MW. After several years of successful operation, the owner decided that the tube degradation rates of the original steam generators were too high for the plant to meet the performance requirements for the full 40-year license period. The contract to supply replacement steam generators (RSGs) was awarded to Westinghouse Electric Company in 1996. Installation of these RSGs took place in the last months of 2000. This paper compares the design features of the original and re-placement steam generators with emphasis on design and reliability enhancements achieved. (author)

Hydrogen-oxygen steam generator applications for increasing the efficiency, maneuverability and reliability of power production

Science.gov (United States)

Schastlivtsev, A. I.; Borzenko, V. I.

2017-11-01

The comparative feasibility study of the energy storage technologies showed good applicability of hydrogen-oxygen steam generators (HOSG) based energy storage systems with large-scale hydrogen production. The developed scheme solutions for the use of HOSGs for thermal power (TPP) and nuclear power plants (NPP), and the feasibility analysis that have been carried out have shown that their use makes it possible to increase the maneuverability of steam turbines and provide backup power supply in the event of failure of the main steam generating equipment. The main design solutions for the integration of hydrogen-oxygen steam generators into the main power equipment of TPPs and NPPs, as well as their optimal operation modes, are considered.

A steam inerting system for hydrogen disposal for the Vandenberg Shuttle

Science.gov (United States)

Belknap, Stuart B.

1988-01-01

A two-year feasibility and test program to solve the problem of unburned confined hydrogen at the Vandenberg Space Launch Complex Six (SLC-6) during Space Shuttle Main Engine (SSME) firings is discussed. A novel steam inerting design was selected for development. Available sound suppression water is superheated to flash to steam at the duct entrance. Testing, analysis, and design during 1987 showed that the steam inerting system (SIS) solves the problem and meets other flight-critical system requirements. The SIS design is complete and available for installation at SLC-6 to support shuttle or derivative vehicles.

Steam generation: fossil-fired systems: utility boilers; industrial boilers; boiler auxillaries; nuclear systems: boiling water; pressurized water; in-core fuel management; steam-cycle systems: condensate/feedwater; circulating water; water treatment

International Nuclear Information System (INIS)

Anon.

1982-01-01

A survey of development in steam generation is presented. First, fossil-fired systems are described. Progress in the design of utility and industrial boilers as well as in boiler auxiliaries is traced. Improvements in coal pulverizers, burners that cut pollution and improve efficiency, fans, air heaters and economisers are noted. Nuclear systems are then described, including the BWR and PWR reactors, in-core fuel management techniques are described. Finally, steam-cycle systems for fossil-fired and nuclear power plants are reviewed. Condensate/feedwater systems, circulating water systems, cooling towers, and water treatment systems are discussed

Development of data management system for steam generator inspection

International Nuclear Information System (INIS)

Jung, Yong Moo; Im, Chang Jae; Lee, Yoon Sang; Kang, Soon Joo; An, Jong Kwan

1994-06-01

The data communications environment for transferring Nuclear Power Plant Steam Generator Eddy Current testing data was investigated and after connecting LAN to Hinet-F network, the remote data transfer with the speed of 56 kbps was tested successfully. Data management system for Steam Generator Eddy current testing was also developed by using HP-UX, RMB (Rock Mountain Basic) 21 figs, 13 tabs, 5 refs. (Author)

Development of data management system for steam generator inspection

Energy Technology Data Exchange (ETDEWEB)

Jung, Yong Moo; Im, Chang Jae; Lee, Yoon Sang; Kang, Soon Joo; An, Jong Kwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-06-01

The data communications environment for transferring Nuclear Power Plant Steam Generator Eddy Current testing data was investigated and after connecting LAN to Hinet-F network, the remote data transfer with the speed of 56 kbps was tested successfully. Data management system for Steam Generator Eddy current testing was also developed by using HP-UX, RMB (Rock Mountain Basic) 21 figs, 13 tabs, 5 refs. (Author).

Water jet behavior in center water jet type supersonic steam injector

International Nuclear Information System (INIS)

Kawamoto, Y.; Abe, Y.

2005-01-01

Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. As previous studies of the steam injector, there are studies about formulation of operating characteristic of steam injector and analysis of jet structure in steam injector by Narabayashi etc. And as previous studies of the direct contact condensation, there is the study about the direct contact condensation in steam atmosphere. However the study about the turbulent heat transfer under the great shear stress is not enough investigated. Therefore it is necessary to examine in detail about the operating characteristic of the steam injector. The present paper reports the observation results of the water jet behavior in the super sonic steam injector by using the video camera and the high-speed video camera. And the measuring results of the temperature and the pressure distribution in the steam injector are reported. From observation results by video camera, it is cleared that the water jet is established at the center of the steam injector right after steam supplied and the operation of the steam injector depends on the throat diameter. And from observation results by high-speed video camera, it is supposed that the columned water jet surface is established in the mixing nozzle and the water jet surface movement exists. Furthermore and effect of the non-condensable gas on the steam injector is investigated by measuring the radial temperature distributions in the water jet. From measuring results, it is supposed the more the air included in the steam, the more the temperature fluctuation of both steam and discharge water

Mushrooms as Efficient Solar Steam-Generation Devices.

Science.gov (United States)

Xu, Ning; Hu, Xiaozhen; Xu, Weichao; Li, Xiuqiang; Zhou, Lin; Zhu, Shining; Zhu, Jia

2017-07-01

Solar steam generation is emerging as a promising technology, for its potential in harvesting solar energy for various applications such as desalination and sterilization. Recent studies have reported a variety of artificial structures that are designed and fabricated to improve energy conversion efficiencies by enhancing solar absorption, heat localization, water supply, and vapor transportation. Mushrooms, as a kind of living organism, are surprisingly found to be efficient solar steam-generation devices for the first time. Natural and carbonized mushrooms can achieve ≈62% and ≈78% conversion efficiencies under 1 sun illumination, respectively. It is found that this capability of high solar steam generation is attributed to the unique natural structure of mushroom, umbrella-shaped black pileus, porous context, and fibrous stipe with a small cross section. These features not only provide efficient light absorption, water supply, and vapor escape, but also suppress three components of heat losses at the same time. These findings not only reveal the hidden talent of mushrooms as low-cost materials for solar steam generation, but also provide inspiration for the future development of high-performance solar thermal conversion devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of vibration anomalies of main steam lines at Palo Verde-3

International Nuclear Information System (INIS)

Amr, A.; Landstrom, C.; Maxwell, H.; Miller, J.S.; Lynch, J.J.

1996-01-01

Historically, flow induced vibration in piping systems that transport liquid has presented problems for plant designers. When evaluating a vibration problem, it is always important to determine the forcing frequencies from different phenomena and the natural frequencies of the system as an integral part of establishing the root cause of the problem. Since in most cases of large vibration and noise levels, the natural frequency of the system and the frequency of the flow induced vibration are very close, determining the natural frequency of the system is important. Palo Verde Unit-3 exhibited a vibration problem where identification of the root cause was difficult. A Palo Verde team was created which consisted of engineers from different on-site departments and support from consultants. The process used to determine the root cause for the vibration/noise problem on Main Steam Supply System (MSSS) steam line 2 at Palo Verde Unit 3 is discussed in this paper. Since the root cause was not readily apparent, a finite element model was constructed to determine the natural frequency of the piping system. The finite element model consisted of a portion of the main steam lines, including a sample line which traverses the main steam line

Concept of passive safe small reactor for distributed energy supply system

International Nuclear Information System (INIS)

Ishida, Toshihisa; Nakajima, Nobuya; Sawada, Ken-ichi; Yoritsune, Tsutomu; Shimada, Shoichiro; Nakano, Yoshihiro; Yonomoto, Taisuke; Takahashi, Hiroki

2003-01-01

This paper presents a concept of a Passive Safe Small Reactor for Distributed energy supply system (PSRD). The PSRD is an integrated-type PWR with reactor thermal power of 100 to 300 MW aimed at supplying electricity, district heating, etc. In design of the PSRD, high priority is laid on enhancement of safety as well as improvement of economy. Safety is enhanced by the following means: i) Extreme reduction of pipes penetrating the reactor vessel, by limiting to only those of the steam, the feed water and the safety valves, ii) Adoption of the water filled containment and the passive safety systems with fluid driven by natural circulation force, and iii) Adoption of the in-vessel type control rod drive mechanism, accompanying a passive reactor shut-down. To comply with a severe operation condition of PSRD, material of the ball bearing with graphite retainer has been selected by test. For improvement of economy, simplification of the reactor system and long operation of the core are achieved. Optimization of core design concerning the burnable poison ensures the burn-up of 28 GWd/t for low enriched UO 2 fuel rods. (author)

Imitative modeling automatic system Control of steam pressure in the main steam collector with the influence on the main Servomotor steam turbine

Science.gov (United States)

Andriushin, A. V.; Zverkov, V. P.; Kuzishchin, V. F.; Ryzhkov, O. S.; Sabanin, V. R.

2017-11-01

The research and setting results of steam pressure in the main steam collector “Do itself” automatic control system (ACS) with high-speed feedback on steam pressure in the turbine regulating stage are presented. The ACS setup is performed on the simulation model of the controlled object developed for this purpose with load-dependent static and dynamic characteristics and a non-linear control algorithm with pulse control of the turbine main servomotor. A method for tuning nonlinear ACS with a numerical algorithm for multiparametric optimization and a procedure for separate dynamic adjustment of control devices in a two-loop ACS are proposed and implemented. It is shown that the nonlinear ACS adjusted with the proposed method with the regulators constant parameters ensures reliable and high-quality operation without the occurrence of oscillations in the transient processes the operating range of the turbine loads.

Screening reactor steam/water piping systems for water hammer

International Nuclear Information System (INIS)

Griffith, P.

1997-09-01

A steam/water system possessing a certain combination of thermal, hydraulic and operational states, can, in certain geometries, lead to a steam bubble collapse induced water hammer. These states, operations, and geometries are identified. A procedure that can be used for identifying whether an unbuilt reactor system is prone to water hammer is proposed. For the most common water hammer, steam bubble collapse induced water hammer, six conditions must be met in order for one to occur. These are: (1) the pipe must be almost horizontal; (2) the subcooling must be greater than 20 C; (3) the L/D must be greater than 24; (4) the velocity must be low enough so that the pipe does not run full, i.e., the Froude number must be less than one; (5) there should be void nearby; (6) the pressure must be high enough so that significant damage occurs, that is the pressure should be above 10 atmospheres. Recommendations on how to avoid this kind of water hammer in both the design and the operation of the reactor system are made

Synthesis and optimization of steam system networks. 2. Multiple steam levels

CSIR Research Space (South Africa)

Price, T

2010-08-01

Full Text Available The use of steam in heat exchanger networks (HENs) can be reduced by the application of heat integration with the intention of debottlenecking the steam boiler and indirectly reducing the water requirement [Coetzee and Majozi. Ind. Eng. Chem. Res...

A single-stage high pressure steam injector for next generation reactors: test results and analysis

International Nuclear Information System (INIS)

Cattadori, G.; Galbiati, L.; Mazzocchi, L.; Vanini, P.

1995-01-01

Steam injectors can be used in advanced light water reactors (ALWRs) for high pressure makeup water supply; this solution seems to be very attractive because of the ''passive'' features of steam injectors, that would take advantage of the available energy from primary steam without the introduction of any rotating machinery. The reference application considered in this work is a high pressure safety injection system for a BWR; a water flow rate of about 60 kg/s to be delivered against primary pressures covering a quite wide range up to 9 MPa is required. Nevertheless, steam driven water injectors with similar characteristics could be used to satisfy the high pressure core coolant makeup requirements of next generation PWRs. With regard to BWR application, an instrumented steam injector prototype with a flow rate scaling factor of about 1:6 has been built and tested. The tested steam injector operates at a constant inlet water pressure (about 0.2 MPa) and inlet water temperature ranging from 15 to 37 o C, with steam pressure ranging from 2.5 to 8.7 MPa, always fulfilling the discharge pressure target (10% higher than steam pressure). To achieve these results an original double-overflow flow rate-control/startup system has been developed. (Author)

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

Science.gov (United States)

McDermott, Daniel J.; Schrader, Kenneth J.; Schulz, Terry L.

1994-01-01

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

Steam turbines for nuclear power stations in Czechoslovakia and their use for district heating

International Nuclear Information System (INIS)

Drahy, J.

1989-01-01

The first generation of nuclear power stations in Czechoslavakia is equipped with 440 MW e pressurized water reactors. Each reactor supplies two 220 MW, 3000 rpm condensing type turbosets operating with saturated steam. After the completion of heating water piping systems, all of the 24 units of 220 MW in Czechoslovak nuclear power stations will be operated as dual purpose units, delivering both electricity and heat. At the present time, second-generation nuclear power stations, with 1000 MW e PWRs, are being built. Each such plant is equipped with one 1000 MW full-speed saturated steam turbine. The turbine is so designed as to permit the extraction of steam corresponding to the following quantities of heat: 893 MJ/s with three-stage water heating (150/60 0 C); and 570 MJ/s with two-stage water heating (120/60 0 C). The steam is taken from uncontrolled steam extraction points. (author)

Steam systems in industry: Energy use and energy efficiency improvement potentials

International Nuclear Information System (INIS)

Einstein, Dan; Worrell, Ernst; Khrushch, Marta

2001-01-01

Steam systems are a part of almost every major industrial process today. Thirty-seven percent of the fossil fuel burned in US industry is burned to produce steam. In this paper we will establish baseline energy consumption for steam systems. Based on a detailed analysis of boiler energy use we estimate current energy use in boilers in U.S. industry at 6.1 Quads (6.4 EJ), emitting almost 66 MtC in CO(sub 2) emissions. We will discuss fuels used and boiler size distribution. We also describe potential savings measures, and estimate the economic energy savings potential in U.S. industry (i.e. having payback period of 3 years or less). We estimate the nationwide economic potential, based on the evaluation of 16 individual measures in steam generation and distribution. The analysis excludes the efficient use of steam and increased heat recovery. Based on the analysis we estimate the economic potential at 18-20% of total boiler energy use, resulting in energy savings approximately 1120-1190 TBtu ( 1180-1260 PJ). This results in a reduction of CO(sub 2) emissions equivalent to 12-13 MtC

Design of fault tolerant control system for steam generator using

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Ki; Seo, Mi Ro [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1998-12-31

A controller and sensor fault tolerant system for a steam generator is designed with fuzzy logic. A structure of the proposed fault tolerant redundant system is composed of a supervisor and two fuzzy weighting modulators. A supervisor alternatively checks a controller and a sensor induced performances to identify which part, a controller or a sensor, is faulty. In order to analyze controller induced performance both an error and a change in error of the system output are chosen as fuzzy variables. The fuzzy logic for a sensor induced performance uses two variables : a deviation between two sensor outputs and its frequency. Fuzzy weighting modulator generates an output signal compensated for faulty input signal. Simulations show that the proposed fault tolerant control scheme for a steam generator regulates well water level by suppressing fault effect of either controllers or sensors. Therefore through duplicating sensors and controllers with the proposed fault tolerant scheme, both a reliability of a steam generator control and sensor system and that of a power plant increase even more. 2 refs., 9 figs., 1 tab. (Author)

Dual turbine power plant and method of operating such plant, especially one having an HTGR steam supply

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegtnes, K.O.

1977-01-01

A power plant including dual steam turbine-generators connected to pass superheat and reheat steam from a steam generator which derives heat from the coolant gas of a high temperature gas-cooled nuclear reactor is described. Associated with each turbine is a bypass line to conduct superheat steam in parallel with a high pressure turbine portion, and a bypass line to conduct superheat steam in parallel with a lower pressure turbine portion. Auxiliary steam turbines pass a portion of the steam flow to the reheater of the steam generator and drive gas blowers which circulate the coolant gas through the reactor and the steam source. Apparatus and method are disclosed for loading or unloading a turbine-generator while the other produces a steady power output. During such loading or unloading, the steam flows through the turbine portions are coordinated with the steam flows through the bypass lines for protection of the steam generator, and the pressure of reheated steam is regulated for improved performance of the gas blowers. 33 claims, 5 figures

Correction of Pressure Drop in Steam and Water System in Performance Test of Boiler

Science.gov (United States)

Liu, Jinglong; Zhao, Xianqiao; Hou, Fanjun; Wu, Xiaowu; Wang, Feng; Hu, Zhihong; Yang, Xinsen

2018-01-01

Steam and water pressure drop is one of the most important characteristics in the boiler performance test. As the measuring points are not in the guaranteed position and the test condition fluctuation exsits, the pressure drop test of steam and water system has the deviation of measuring point position and the deviation of test running parameter. In order to get accurate pressure drop of steam and water system, the corresponding correction should be carried out. This paper introduces the correction method of steam and water pressure drop in boiler performance test.

Development and application of an entrainment model for the PWR U-tube steam generators for main steam line break analysis

International Nuclear Information System (INIS)

Song, Dong-Soo; Park, Young-Chan

2004-01-01

The purpose of this paper is to present the analyses that were performed to develop and use an entrainment model for pressurized water reactor U-tube steam generators (SG) for main steam line break (MSLB) analyses. The entrainment model was developed using the RETRAN-3D computer program, and the model was benchmarked against experimental data of moisture carryover during a simulated MSLB accident. The application methodology was also developed to incorporate into the MSLB mass and energy release calculations for Kori Unit 1. This methodology utilizes LOFTRAN and RETRAN-3D codes in an iterative sequence of cases in which the LOFTRAN nuclear steam supply system model provides boundary conditions for the RETRAN-3D broken loop steam generator model, and the RETRAN-3D model provides the entrainment data that is input back into the LOFTRAN model. FORTRAN programs were developed to facilitate the sequencing of these iterative calculations. As a result of applying the entrainment model to Kori Unit 1, the temperature calculated inside Containment during MSLB accident using the CONTEMP-LT computer program decreased by about 25degC. Consequently this entrainment model provides a significant benefit by decreasing the temperature envelop for environment qualification as well as decreasing the peak Containment pressure. (author)

An assessment of underground and aboveground steam system failures in the SRS waste tank farms

International Nuclear Information System (INIS)

Hsu, T.C.; Shurrab, M.S.; Wiersma, B.J.

1997-01-01

Underground steam system failures in waste tank farms at the Savannah River Site (SRS) increased significantly in the 3--4 year period prior to 1995. The primary safety issues created by the failures were the formation of sub-surface voids in soil and the loss of steam jet transfer and waste evaporation capability, and the loss of heating and ventilation to the tanks. The average annual cost for excavation and repair of the underground steam system was estimated to be several million dollars. These factors prompted engineering personnel to re-consider long-term solutions to the problem. The primary cause of these failures was the inadequate thermal insulation utilized for steam lines associated with older tanks. The failure mechanisms were either pitting or localized general corrosion on the exterior of the pipe beneath the thermal insulation. The most realistic and practical solution is to replace the underground lines by installing aboveground steam systems, although this option will incur significant initial capital costs. Steam system components, installed aboveground in other areas of the tank farms have experienced few failures, while in continuous use. As a result, piecewise installation of temporary aboveground steam systems have been implemented in F-area whenever opportunities, i.e., failures, present themselves

400-MWe consolidated nuclear steam system (CNSS): 1200-MWt/conceptual design

International Nuclear Information System (INIS)

1977-06-01

A 1200-MWt consolidated nuclear steam system (CNSS) conceptual design is described. The concept, derived from nuclear merchant ship propulsion steam systems but distinctly different from those systems in detail, incorporates the steam generators within the reactor pressure vessel. This configuration eliminates primary coolant circulating piping external to the reactor pressure vessel since the primary coolant circulating pumps are mounted in the pressure vessel head. So arranged, the maximum piping break that must be assumed is that of the pressurizer surge line, which is substantially smaller than a primary coolant circulating line. A fracture of the pressurizer surge line would result in substantially lower mass and energy release rates of the primary coolant during the assumed loss-of-coolant accident. This in turn makes practical a pressure-suppression containment rather than the ''dry'' containment commonly used for pressurized water reactors

Technical specifications for the provision of heat and steam sources for INPP and Visaginas. Final report

International Nuclear Information System (INIS)

2003-01-01

In October 1999, the National Energy Strategy was approved by the Lithuanian Parliament. The National Energy Strategy included the decision to close Unit-1 of INPP before 2005. Later is has been decided to close Unit 2 before the end of 2009 as well. The closure and decommissioning will have heavy impact on the heat supply for the city of Visaginas. Unit 1 and Unit 2 of INPP supplies hot water and steam to INPP for process purposes and for space heating of residential and commercial buildings. When Unit 1 is permanently shut down, reliable heat and steam sources independent of the power plants own heat and steam generation facilities are required for safety reasons in the event of shutdown of the remaining unit for maintenance or in an emergency. These steam and heat sources must be operational before single unit operation is envisaged. Provision of a reliable independent heat and steam source is therefore urgent. After both reactors are shut down permanently, a steam source will be needed at the plant for radioactive waste storage and disposal. INPP and DEA has performed a feasibility study for the provision of a reliable heat source for Ignalina Nuclear Power Plant and Visaginas, and the modernisation of Visaginas district heating system. The objective of this project is to prepare technical specifications for the provision of new heat and steam sources for INPP and Visaginas, and for rehabilitation of the heat transmission pipeline between INPP, the back-up boiler station and Visaginas City. The results of the study are presented in detail in the reports and technical specifications: 1. Transient analysis for Visaginas DH system, 2. Non-destructive testing of boiler stations, pump stations and transmission lines, 3. Conceptual design, 4. Technical specifications, Package 1 to 6. The study has suggested: 1. Construction of new steam boiler station, 2. Construction of new heat only boiler station, 3. Renovation of existing back-up heat only boiler station, 4

Steam generators, turbines, and condensers. Volume six

International Nuclear Information System (INIS)

Anon.

1986-01-01

Volume six covers steam generators (How steam is generated, steam generation in a PWR, vertical U-tube steam generators, once-through steam generators, how much steam do steam generators make?), turbines (basic turbine principles, impulse turbines, reaction turbines, turbine stages, turbine arrangements, turbine steam flow, steam admission to turbines, turbine seals and supports, turbine oil system, generators), and condensers (need for condensers, basic condenser principles, condenser arrangements, heat transfer in condensers, air removal from condensers, circulating water system, heat loss to the circulating water system, factors affecting condenser performance, condenser auxiliaries)

Water treatment in the EBR-II steam system

International Nuclear Information System (INIS)

Klein, M.A.; Hurst, H.

1975-01-01

Boiler-water treatment in the EBR-II steam system consists of demineralizing makeup water and using hydrazine to remove traces of oxygen and morpholine to adjust pH to 8.8-9.2. This treatment is called a ''zero-solids'' method, because the chemical agents and reaction products are either volatile or form water and do not contribute solids to the boiler water. A continuous blowdown is cooled, filtered, and deionized to remove impurities and maintain high purity of the water. If a cooling-water leak occurs, phosphate is added to control scaling, and the ''zero-solids'' eatment is suspended until the leak is repaired. Water streams are sampled at six points to control water purity. Examination of the steam drum and an evaporator show the metal surfaces to be in excellent condition with minimal corrosion. The EBR-II steam-generating plant has accumulated over 85,000 hours of in-service operation and has operated successfully for over ten years with the ''zero-solids'' treatment. (auth)

Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

Science.gov (United States)

Mwara, Kamwana N.

2015-01-01

Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

Testing improved steam separators in third energy block of Chernobyl AES

Energy Technology Data Exchange (ETDEWEB)

Novosel' skiy, O Yu; Karasev, V B; Sakovich, E V; Lyutov, M A; An' kov, V I

1984-12-01

Improved steam separating drums are described. These have a four-row arrangement of the pipe unions of the steam-water supply lines, with increased diameter. Two collectors 400 mm in diameter from adjacent separators drums go to a single steam line 600 mm in diameter, which goes to the turbine. Tests of the system were conducted at a pressure of 7 MPa and at thermal power of 65, 83, 93, and 100% of rated value to determine the dependence of the moisture content at the output from the separator drum on the mass level at constant thermal power of the block. The separator drums, 2600 mm in diameter, were found to have a reserve for maximum permissible moisture content, and the moisture content of the steam in the central pipe unions did not exceed 0.02% with a level in the drums 200 mm above the rated level. Thus maintenance of the level above the submerged perforated plate by 100 mm above the planned level permits an increase of the water reserve in the multiple forced circulation circuit by 28 m/sup 3/ and does not hinder an increase of the steam productivity of the block.

Effects of the steam chest on steamhammer analysis for nuclear piping systems

International Nuclear Information System (INIS)

Luk, C.

1975-01-01

When applying the method of characteristics for the steamhammer analysis of a nuclear piping system, if the dynamic fluid behavior in the steam chest is not considered, the boundary condition thus formulated to describe the time-dependent fluid behavior of the steam chest would lead to numerical unstable solution. To overcome this difficulty, the dynamic fluid behavior in the steam chest can be described by a single degree mechanical system. The corresponding flow conditions there are then determined by the time-step amplification method. This dynamic boundary condition reduces the calculated steamhammer loads and helps avoid numerical instability problems in the computing procedure. 4 refs

Design of helium-gas supplying facility of out-of-pile demonstration test for HTTR heat utilization system

Energy Technology Data Exchange (ETDEWEB)

Hino, Ryutaro; Fujisaki, Katsuo; Kobayashi, Toshiaki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

1996-09-01

One of the objectives of the High-Temperature Engineering Test Reactor (HTTR) is to demonstrate effectiveness of high-temperature heat utilization. Prior to connect a heat utilization system to the HTTR, a series of out-of-pile demonstration test is indispensable to improve components` performance, to demonstrate operation, control and safety technologies and to verify analysis codes for design and safety evaluation. After critical review and discussion on the out-of-pile demonstration test, a test facility have been designed. In this report, a helium-gas supplying facility simulated the HTTR system was described in detail, which supplies High-temperature helium-gas of 900degC to a steam reforming facility mocking-up the HTTR heat utilization system. Components of the Helium Engineering Demonstration Loop (HENDEL) were selected to reuse in the helium-gas supplying facility in order to decrease construction cost. Structures and specifications of new components such as a high-temperature heater and a preheater were decided after evaluation of thermal and hydraulic performance and strength. (author)

Makeup water system performance and impact on PWR steam generator corrosion

International Nuclear Information System (INIS)

Bell, M.J.; Sawocha, S.G.; Smith, L.A.

1984-01-01

The object of this EPRI-funded project was to assess the possible relation of pressurized water reactor (PWR) steam generator corrosion at fresh water sites to makeup water impurity ingress. Makeup water system design, operation and performance reviews were based on site visits, plant design documents, performance records and grab sample analyses. Design features were assessed in terms of their effect on makeup system performance. Attempts were made to correlate the makeup plant source water, system design characteristics, and typical makeup water qualities to steam generator corrosion observations, particularly intergranular attack (IGA). Direct correlations were not made since many variables are involved in the corrosion process and in the case of IGA, the variables have not been clearly established. However, the study did demonstrate that makeup systems can be a significant source of contaminants that are suspected to lead to both IGA and denting. Additionally, it was noted that typical makeup system performance with respect to organic removal was not good. The role of organics in steam generator damage has not been quantified and may deserve further study

A non-conventional interpretation of thermal regeneration in steam cycles

International Nuclear Information System (INIS)

Bracco, Stefano; Damiani, Lorenzo

2012-01-01

Highlights: ► A better understanding of the concept of thermal regeneration in steam cycles. ► Use of a system composed by a non-regenerative cycle and several reverse cycles. ► Calculation of the heat pumps coefficients of performance. ► New interesting formulations of the regenerative cycle efficiency. -- Abstract: The paper aims to contribute to a better understanding of the thermodynamic concept of heat regeneration in steam power plants with a finite number of bleedings. A regenerative Rankine cycle is compared to a complex system (CHC – complete hybrid cycle) composed by one non-regenerative Rankine cycle (HEC – hybrid engine cycle) and more reverse cycles (RCs – reverse cycles), as many as the number of the bleedings, able to pump heat from the condenser to a series of surface feedwater heaters, disposed upstream of the steam plant boiler. The COPs (coefficients of performance) of the heat pumps are evaluated, and new interesting formulations of the efficiency of the regenerative steam cycle are proposed. In particular a steam cycle with two bleedings is analyzed, neglecting heat losses and pressure drops in the boiler and considering irreversibility only along the expansion line of the steam turbine and into the feedwater heaters. The efficiency and the work of the regenerative cycle are compared to the analogous values of the CHC cycle composed by one simple steam cycle (HEC) and two heat pump cycles (RCs), with steam as the working fluid. The two reverse cycles are considered completely reversible and raising heat from the condenser temperature to the bled steam condensing temperature. The paper shows the most significant results of the study in order to analyze the regenerative cycle and the CHC cycle in comparison with the non-regenerative Rankine cycle; in particular, the analysis is focused on the evaluation of the useful work, the heat supplied and the heat rejected for the examined cycles.

Device indicating start of steam or water reaction with sodium and damage of steam generator heat exchange tube wall

International Nuclear Information System (INIS)

Jung, J.; Sobotka, J.

1984-01-01

Eddy currents induced by the alternating current of an exciting coil in the vicinity of steam or water leakage are used for indication. The coil is supplied from a power amplifier whose input is connected to an exciting generator by two measuring coils connected across each other. Their voltage is applied to a differential amplifier with an indicator. The equipment may be used for steam generators of nuclear power plants with sodium cooled reactors. (E.F.)

Design of a steam reforming system to be connected to the HTTR

International Nuclear Information System (INIS)

Hada, K.; Nishihara, T.; Shibata, T.; Shiozawa, S.

1996-01-01

Top priority objective for developing the first heat utilization system to be connected to the HTTR is to demonstrate technical feasibility of a nuclear process heat utilization system for production of hydrogen for the first time in the world. Major issues to be resolved for coupling the heat utilization system to the HTTR are 1)to develop safety philosophy for reasonably and reliably ensuring safety of the nuclear reactor, 2)to develop control design concept for the total system of the nuclear reactor and heat utilization system because thermal dynamics of endothermic chemical reactor to be heated by nuclear heat is much different from the nuclear reactor, 3)to develop helium-heated components and 4)to develop enhanced hydrogen production technologies for achieving competitiveness to a fossil-fired plant. A steam reforming hydrogen production system was studied as one of the first priority candidates for an HTTR-heat utilization system due to matured technology in fossil-fired plants and since technical solutions demonstrated by the coupling of the steam reforming system to the HTTR will contribute to all other hydrogen production systems. Basic design philosophy for the HTTR-steam reforming system is that the steam reforming plant downstream of an intermediate secondary helium loop is designed at the same safety level as fossil-fired plants and therefore the secondary helium loop was selected as a safety barrier to the HTTR nuclear reactor. (J.P.N.)

Aerogel-Based Insulation for Industrial Steam Distribution Systems

Energy Technology Data Exchange (ETDEWEB)

John Williams

2011-03-30

Thermal losses in industrial steam distribution systems account for 977 trillion Btu/year in the US, more than 1% of total domestic energy consumption. Aspen Aerogels worked with Department of Energy’s Industrial Technologies Program to specify, develop, scale-up, demonstrate, and deliver Pyrogel XT®, an aerogel-based pipe insulation, to market to reduce energy losses in industrial steam systems. The product developed has become Aspen’s best selling flexible aerogel blanket insulation and has led to over 60 new jobs. Additionally, this product has delivered more than ~0.7 TBTU of domestic energy savings to date, and could produce annual energy savings of 149 TBTU by 2030. Pyrogel XT’s commercial success has been driven by it’s 2-4X better thermal performance, improved durability, greater resistance to corrosion under insulation (CUI), and faster installation times than incumbent insulation materials.

THE CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

International Nuclear Information System (INIS)

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb; Jacqueline G. Broder

2001-01-01

and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system have been completed and a cost estimate for steam supply system was completed. The cost estimate and the output and heat rate impacts will be used to determine a preliminary price for the exported steam. The preliminary steam price will be determined in the next quarter

Auxiliary water supply device for BWR type reactor

International Nuclear Information System (INIS)

Sasagawa, Hiroshi.

1994-01-01

In the device of the present invention, a cooling condensation means is disposed to a steam discharge channel of a turbine for driving pumps to directly return condensates to the reactor, so that the temperature of the suppression pool water is not elevated. Namely, the cooling condensation means for discharged steams is disposed to the discharge channel of the turbine. The condensate channel from the cooling condensation means is connected to a sucking side of the turbine driving pump. With such a constitution, when the reactor is isolated from a main steam system, reactor scram is conducted. Although the reactor water level is lowered by the reactor scram, the lowering of the reactor water level is prevented by supplementing cooling water by the turbine driving pump using steams generated in the reactor as a power source. The discharged steams after driving the turbine are cooled and condensated by the cooling condensation means by way of the discharge channel and returned to the reactor again by way of the condensate channel. With such procedures, since the temperature of suppression pool water is not elevated, there is no need to operate other cooling systems. In addition, auxiliary water can be supplied for a long period of time. (I.S.)

Optimal Operations and Resilient Investments in Steam Networks

Energy Technology Data Exchange (ETDEWEB)

Bungener, Stéphane L., E-mail: stephane.bungener@a3.epfl.ch [Industrial Process and Energy Systems Engineering, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Van Eetvelde, Greet [Environmental and Spatial Management, Faculty of Engineering and Architecture, Ghent University, Ghent (Belgium); Maréchal, François [Industrial Process and Energy Systems Engineering, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland)

2016-01-20

Steam is a key energy vector for industrial sites, most commonly used for process heating and cooling, cogeneration of heat and mechanical power as a motive fluid or for stripping. Steam networks are used to carry steam from producers to consumers and between pressure levels through letdowns and steam turbines. The steam producers (boilers, heat and power cogeneration units, heat exchangers, chemical reactors) should be sized to supply the consumers at nominal operating conditions as well as peak demand. First, this paper proposes an Mixed Integer Linear Programing formulation to optimize the operations of steam networks in normal operating conditions and exceptional demand (when operating reserves fall to zero), through the introduction of load shedding. Optimization of investments based on operational and investment costs are included in the formulation. Though rare, boiler failures can have a heavy impact on steam network operations and costs, leading to undercapacity and unit shutdowns. A method is therefore proposed to simulate steam network operations when facing boiler failures. Key performance indicators are introduced to quantify the network’s resilience. The proposed methods are applied and demonstrated in an industrial case study using industrial data. The results indicate the importance of oversizing key steam producing equipments and the value of industrial symbiosis to increase industrial site resilience.

Optimal Operations and Resilient Investments in Steam Networks

International Nuclear Information System (INIS)

Bungener, Stéphane L.; Van Eetvelde, Greet; Maréchal, François

2016-01-01

Steam is a key energy vector for industrial sites, most commonly used for process heating and cooling, cogeneration of heat and mechanical power as a motive fluid or for stripping. Steam networks are used to carry steam from producers to consumers and between pressure levels through letdowns and steam turbines. The steam producers (boilers, heat and power cogeneration units, heat exchangers, chemical reactors) should be sized to supply the consumers at nominal operating conditions as well as peak demand. First, this paper proposes an Mixed Integer Linear Programing formulation to optimize the operations of steam networks in normal operating conditions and exceptional demand (when operating reserves fall to zero), through the introduction of load shedding. Optimization of investments based on operational and investment costs are included in the formulation. Though rare, boiler failures can have a heavy impact on steam network operations and costs, leading to undercapacity and unit shutdowns. A method is therefore proposed to simulate steam network operations when facing boiler failures. Key performance indicators are introduced to quantify the network’s resilience. The proposed methods are applied and demonstrated in an industrial case study using industrial data. The results indicate the importance of oversizing key steam producing equipments and the value of industrial symbiosis to increase industrial site resilience.

Steam-Generator Integrity Program/Steam-Generator Group Project

International Nuclear Information System (INIS)

1982-10-01

The Steam Generator Integrity Program (SGIP) is a comprehensive effort addressing issues of nondestructive test (NDT) reliability, inservice inspection (ISI) requirements, and tube plugging criteria for PWR steam generators. In addition, the program has interactive research tasks relating primary side decontamination, secondary side cleaning, and proposed repair techniques to nondestructive inspectability and primary system integrity. The program has acquired a service degraded PWR steam generator for research purposes. This past year a research facility, the Steam Generator Examination Facility (SGEF), specifically designed for nondestructive and destructive examination tasks of the SGIP was completed. The Surry generator previously transported to the Hanford Reservation was then inserted into the SGEF. Nondestructive characterization of the generator from both primary and secondary sides has been initiated. Decontamination of the channelhead cold leg side was conducted. Radioactive field maps were established in the steam generator, at the generator surface and in the SGEF

Steam generator

International Nuclear Information System (INIS)

Fenet, J.-C.

1980-01-01

Steam generator particularly intended for use in the coolant system of a pressurized water reactor for vaporizing a secondary liquid, generally water, by the primary cooling liquid of the reactor and comprising special arrangements for drying the steam before it leaves the generator [fr

An expert system for diagnostics and estimation of steam turbine components condition

Science.gov (United States)

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

2017-11-01

The report describes an expert system of probability type for diagnostics and state estimation of steam turbine technological subsystems components. The expert system is based on Bayes’ theorem and permits to troubleshoot the equipment components, using expert experience, when there is a lack of baseline information on the indicators of turbine operation. Within a unified approach the expert system solves the problems of diagnosing the flow steam path of the turbine, bearings, thermal expansion system, regulatory system, condensing unit, the systems of regenerative feed-water and hot water heating. The knowledge base of the expert system for turbine unit rotors and bearings contains a description of 34 defects and of 104 related diagnostic features that cause a change in its vibration state. The knowledge base for the condensing unit contains 12 hypotheses and 15 evidence (indications); the procedures are also designated for 20 state parameters estimation. Similar knowledge base containing the diagnostic features and faults hypotheses are formulated for other technological subsystems of turbine unit. With the necessary initial information available a number of problems can be solved within the expert system for various technological subsystems of steam turbine unit: for steam flow path it is the correlation and regression analysis of multifactor relationship between the vibration parameters variations and the regime parameters; for system of thermal expansions it is the evaluation of force acting on the longitudinal keys depending on the temperature state of the turbine cylinder; for condensing unit it is the evaluation of separate effect of the heat exchange surface contamination and of the presence of air in condenser steam space on condenser thermal efficiency performance, as well as the evaluation of term for condenser cleaning and for tube system replacement and so forth. With a lack of initial information the expert system enables to formulate a diagnosis

Response of the steam generator VVER 1000 to a steam line break

International Nuclear Information System (INIS)

Novotny, J.; Novotny, J. Jr.

2003-01-01

Dynamic effects of a steam line break in the weld of the steam pipe and the steam collector on the steam generator system are analyzed. Modelling of a steam line break may concern two cases. The steam line without a restraint and the steam line protected by a whip restraint with viscous elements applied at the postulated break cross-section. The second case is considered. Programme SYSTUS offers a special element the stiffness and viscous damping coefficients of which may be defined as dependent on the relative displacement and velocity of its nodes respectively. A circumferential crack is simulated by a sudden decrease of longitudinal and lateral stiffness coefficients of these special SYSTUS elements to zero. The computation has shown that one can simulate the pipe to behave like completely broken during a time interval of 0,0001 s or less. These elements are used to model the whip restraint with viscous elements and viscous dampers of the GERB type as well. In the case of a whip restraint model the stiffness coefficient-displacement relation and damping coefficient - velocity relation are chosen to fit the given characteristics of the restraint. The special SYSTUS elements are used to constitute Maxwell elements modelling the elasto-plastic and viscous properties of the GERB dampers applied to the steam generator. It has been ascertained that a steam line break at the postulated weld crack between the steam pipe and the steam generator collector cannot endanger the integrity of the system even in a case of the absence of a whip restraint effect. (author)

Steam purity in PWRs

International Nuclear Information System (INIS)

Hopkinson, J.

1982-01-01

Impurities enter the secondary loop of the PWR through both makeup water from lake or well and cooling-water leaks in the condenser. These impurities can be carried to the steam generator, where they cause corrosion deposits to form. Corrosion products in steam are swept further through the system and become concentrated at the point in the low-pressure turbine where steam begins to condense. Several plants have effectively reduced impurities, and therefore corrosion, by installing a demineralizer for the makeup water, a resin-bed system to clean condensed steam from the condenser, and a deaerator to remove oxygen from the water and so lower the risk of system metal oxidation. 5 references, 1 figure

Operational control and maintenance integrity of typical and atypical coil tube steam generating systems

Energy Technology Data Exchange (ETDEWEB)

Beardwood, E.S.

1999-07-01

Coil tube steam generators are low water volume to boiler horsepower (bhp) rating, rapid steaming units which occupy substantially less space per boiler horsepower than equivalent conventional tire tube and water tube boilers. These units can be retrofitted into existing steam systems with relative ease and are more efficient than the generators they replace. During the early 1970's they became a popular choice for steam generation in commercial, institutional and light to medium industrial applications. Although these boiler designs do not require skilled or certified operators, an appreciation for a number of the operational conditions that result in lower unscheduled maintenance, increased reliability and availability cycles would be beneficial to facility owners, managers, and operators. Conditions which afford lower operating and maintenance costs will be discussed from a practical point of view. An overview of boiler design and operation is also included. Pitfalls are provided for operational and idle conditions. Water treatment application, as well as steam system operations not conducive to maintaining long term system integrity; with resolutions, will be addressed.

Conceptual design of small-sized HTGR system (4). Plant design and technical feasibility

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Yan, Xing L.; Sumita, Junya; Nomoto, Yasunobu; Tazawa, Yujiro; Noguchi, Hiroki; Imai, Yoshiyuki; Tachibana, Yukio

2013-09-01

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a 50MWt small-sized high temperature gas cooled reactor (HTGR) for steam supply and electricity generation (HTR50S), which is a first-of-kind of the commercial plant or a demonstration plant of a small-sized HTGR system for steam supply to the industries and district heating and electricity generation by a steam turbine, to deploy in developing countries in the 2020s. HTR50S was designed for steam supply and electricity generation by the steam turbine with the reactor outlet temperature of 750degC as a reference plant configuration. On the other hand, the intermediate heat exchanger (IHX) will be installed in the primary loop to demonstrate the electricity generation by the helium gas turbine and hydrogen production by thermochemical water splitting by utilizing the secondary helium loop with the reactor outlet temperature of 900degC as a future plant configuration. The plant design of HTR50S for the steam supply and electricity generation was performed based on the plant specification and the requirements for each system taking into account for the increase of the reactor outlet coolant temperature from 750degC to 900degC and the installation of IHX. The technical feasibility of HTR50S was confirmed because the designed systems (i.e., reactor internal components, reactor pressure vessel, vessel cooling system, shutdown cooling system, steam generator (SG), gas circulator, SG isolation and drainage system, reactor containment vessel, steam turbine and heat supply system) satisfies the design requirements. The conceptual plant layout was also determined. This paper provides the summary of the plan design and technical feasibility of HTR50S. (author)

Energy and supply concepts. Pt. 3. Energie- und Versorgungskonzepte. T. 3

Energy Technology Data Exchange (ETDEWEB)

Kolodziejczyk, K

1989-01-01

Part three deals with the classification of energy and supply concepts (primary and secondary energy sources, energy conversion processes). A discussion of classification criteria (4 criteria, different process levels) is followed by a description of process and energy flows (flowsheet showing the energy flow of an interconnected system combining electric power/steam/heat supplies and refrigeration), a presentation of concrete energy and supply concepts (flow sheet, selection and evaluation criteria, situation and process analysis, cost-benefit analysis, use of computers, system value analysis), approaches and solutions (decisions). The complex task of finding appropriate supply solutions is found to be depending on the knowledge, creativity, and methodical skill of those in charge. (HWJ).

ASTRID power conversion system: Assessment on steam and gas options

International Nuclear Information System (INIS)

Laffont, Guy; Cachon, Lionel; Jourdain, Vincent; Fauque, Jean Marie

2013-01-01

Conclusion: ◆ Two power conversion systems have been investigated for the ASTRID prototype. ◆ Steam PCS: • Most mature system based on a well-developed turbomachinery technology. • High plant efficiency. • Studies on steam generators designs and leak detection systems in progress with the aim of reducing the risk of large SWRs and of limiting its consequences. • Design and licensing safety assessment of a SFR must deal with the Sodium Water Air reaction (SWAR). ◆ Gas PCS: • Strong advantage as it inherently eliminates the SWR and SWAR risks. • Very innovative option: major breakthroughs but feasibility and viability not yet demonstrated. • Remaining technological challenges but no showstopper indentified. • General architecture: investigations in progress to improve performances, operability and maintainability

Effects of SO2 emission regulations and fuel prices on levellized energy costs for industrial steam generation options

International Nuclear Information System (INIS)

Ozdogan, Sibel; Arikol, Mahir

1992-01-01

We discuss the impacts of SO 2 emission regulations and fuel prices on levellized energy costs of industrial steam generation options. A computer model called INDUSTEAM has been utilized. The steam-supply options comprise conventional grate-firing, bubbling and circulating fluidized beds, fuel-oil, and natural-gas-fired systems. Fuels of different SO 2 pollution potential have been evaluated assuming six environmental scenarios and varying fuel prices. A capacity range of 10-90 MW th is covered. (author)

Integration of steam injection and inlet air cooling for a gas turbine generation system

International Nuclear Information System (INIS)

Wang, F.J.; Chiou, J.S.

2004-01-01

The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 deg. C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in the power generation system for enhancing power generation capacity and efficiency. Two well-proven techniques, namely steam injection gas turbine (STIG) and inlet air cooling (IAC) are very effective features that can use the generated steam to improve the power generation capacity and efficiency. Since the energy level of the generated steam needed for steam injection is different from that needed by an absorption chiller to cool the inlet air, a proper arrangement is required to implement both the STIG and the IAC features into the simple cycle GENSET. In this study, a computer code was developed to simulate a Tai power's Frame 7B simple cycle GENSET. Under the condition of local summer weather, the benefits obtained from the system implementing both STIG and IAC features are more than a 70% boost in power and 20.4% improvement in heat rate

Energetic and exergetic analysis of a steam turbine power plant in an existing phosphoric acid factory

International Nuclear Information System (INIS)

Hafdhi, Fathia; Khir, Tahar; Ben Yahyia, Ali; Ben Brahim, Ammar

2015-01-01

Highlights: • The operating mode of the factory and the power supply streams are presented. • Energetic Analysis of steam turbine power plant of an existing phosphoric acid factory. • Exergetic Analysis of each component of steam turbine power plant and the different heat recovery system. • Energy, exergy efficiency and irreversibility rates for the main components are determined. • The effect of the operating parameters on the plant performance are analyzed. - Abstract: An energetic and exergetic analysis is conducted on a Steam Turbine Power Plant of an existing Phosphoric Acid Factory. The heat recovery systems used in the different parts of the plant are also considered in the study. Mass, energy and exergy balances are established on the main compounds of the plant. A numerical code is established using EES software to perform the calculations required for the thermal and exergy plant analysis considering real variation ranges of the main operating parameters such as pressure, temperature and mass flow rate. The effects of theses parameters on the system performances are investigated. The main sources of irreversibility are the melters, followed by the heat exchangers, the steam turbine generator and the pumps. The maximum energy efficiency is obtained for the blower followed by the heat exchangers, the deaerator and the steam turbine generator. The exergy efficiency obtained for the heat exchanger, the steam turbine generator, the deaerator and the blower are 88%, 74%, 72% and 66% respectively. The effects of High Pressure steam temperature and pressure on the steam turbine generator energy and exergy efficiencies are investigated.

The EBR-II steam generating system - operation, maintenance, and inspection

International Nuclear Information System (INIS)

Buschman, H.W.; Penney, W.H.; Longua, K.J.

2002-01-01

The Experimental Breeder Reactor II (EBR-II) has operated for 20 years at the Idaho National Engineering Laboratory near Idaho Falls. EBR-II is a Liquid Metal Fast Breeder Reactor (LMFBR) with integrated power producing capability. EBR-II has operated at a capacity factor over 70% in the past few years. Superheated steam is produced by eight natural circulation evaporators, two superheaters, and a conventional steam drum. Steam throttle conditions are 438 C and 8.62 MPa. The designs of the evaporators and superheaters are essentially identical; both are counterflow units with low pressure nonradioactive sodium on the shell side. During the 20 years of operation, components of the steam generator have been subjected to a variety of inspections including visual, dimensional, and ultrasonic. One superheater was removed from service because of anomalous performance and was replaced with an evaporator which was removed, examined, and converted into a superheater. Overall operating experience of the system has been excellent and essentially trouble free. Inspections have not revealed any conditions that are performance or life limiting. (author)

Condensate induced water hammer in a steam distribution system results in fatality

International Nuclear Information System (INIS)

Debban, H.L.; Eyre, L.E.

1996-02-01

Water hammer event s in steam distribution piping interrupt service and have the potential to cause serious injury and property damage. Conditions of condensation induced water hammer are discussed and recommendations aimed to improve safety of steam systems are presented. Condensate induced water hammer events at Hanford, a DOE facility, are examined

The Concept of Steam Pressure Control by Changing the Feedwater Flow during Heatup Operation for an Integral Reactor with a Once-Through Steam Generator

International Nuclear Information System (INIS)

Seo, Jae Kwang; Choi, Ki Yong; Kang, Han Ok; Kim, Young In; Yoon, Ju Hyeon; Zee, Sung Qunn

2005-01-01

The design features of a once-through steam generator (OTSG) for an integral reactor are significantly different from the commercial U-tube type steam generator from several aspects such as the general arrangement, size, operation conditions, and so on. Therefore a sufficient understanding of the thermal-hydraulic characteristics of the OTSG is essential for the design of the nuclear steam supply system (NSSS) and the power conversion system (PCS). It is also necessary to develop operation procedures complying to the unique design features of the OTSG of interest. The OTSG is sized to produce a sufficiently superheated steam during a normal power operation and therefore the secondary system can be simple relative to that of the other types of steam generators. For the plant adopting the OTSG, the steam pressure in the secondary circuit (tube side of the OTSG) is controlled to be constant during a normal power operation. Constant steam pressure is realized by regulating the control valve on the main steam line dedicated for this purpose. However during a heatup operation, at which the fluid state at the exit of the OTSG is a single phase hot water or two phases, it is not proper to use the control valve on the main steam line due to a control problem at low and multi-phase flow conditions and possibly an erosion problem. For these reasons, another dedicated line called a startup cooling line is used during a heatup condition. There may be several operational conditions for the secondary fluid required to pass through during heatup operation, depending on the design of the PCS. In general, there are two conditions: One is a condition for a vacuum operation for the condenser and another is an entry condition for a steam pressure control operation for an auxiliary power system. In this study, the concept of using a simple startup cooling line with a fixed flow resistance and changing the feedwater flow for the pressure control of the PCS during a heatup period are

Dynamic modeling and simulation of EBR-II steam generator system

International Nuclear Information System (INIS)

Berkan, R.C.; Upadhyaya, B.R.

1989-01-01

This paper presents a low order dynamic model of the Experimental breeder Reactor-II (EBR-II) steam generator system. The model development includes the application of energy, mass and momentum balance equations in state-space form. The model also includes a three-element controller for the drum water level control problem. The simulation results for low-level perturbations exhibit the inherently stable characteristics of the steam generator. The predictions of test transients also verify the consistency of this low order model

Experience in adjusting of the level regulation system of steam generators of the Rovno NPP

International Nuclear Information System (INIS)

Patselyuk, S.N.; Sokolov, A.G.; Kazakov, V.I.; Dorosh, Yu.A.

1984-01-01

A system of feed water level control in steam generators at the Rovno NPP with WWER-440 reactors which comprises start-up as well as main regulators is described. The start-up regulator (single-pulsed with a signal by the level) keeps the level in the steam generator at loadings up to 30% of the nominal reactor power Nsub(nom.) The main regulator is connected in the three-pulsed circuit and it receives signals by steam and water flow rate and by the level in the steam generator. The main regulator has been started only at loadings above 40% Nsub(nom.). After reconstruction it was used in the 15-100% Nsub(nom.) range. Characteristics of the level control system in the steam generator at perturbations intoduced by the main circulating pump (MCP) and turbine disconnection as well as change in feed water flow rate have been studied. The studies have revealed that the system ensures necessary quality of control in stationary modes. The system operates stably at perturbations of feed water flow rate up to 50% Nsub(nom.). Perturbations by MCP connections and disconnections is most difficult for control system

Reliability analysis of self-supply system of V-1 nuclear power plant

International Nuclear Information System (INIS)

Kuklik, B.

The results are summarized of the fault tree analysis of the V-1 power plant self-consumption system. The 6 kV busbars providing power for the main circulating pumps, the steam generator feed pumps and other important components including the 0.4 kV busbars are of the highest importance for nuclear safety. A fault tree analysis was also made of the emergency core cooling system of the reactor. Dangerous faults are defined and fault trees are developed. A brief description is given of the calculation algorithm for a digital computer. Some results are discussed. The calculated reliability of the emergency core cooling system is 10 5 years, of the 6 kV busbars it is 6.6x10 4 years. In case of a permanent or a long-term outage of the 220 kV stand-bye power supply, the system reliability is reduced to 7x10 2 years. (Z.M.)

A system for regulating the pressure of resuperheated steam in high temperature gas-cooled reactor power stations

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegines, K.O.

1975-01-01

The invention relates to a system for regulating steam-pressure in the re-superheating portion of a steam-boiler receiving heat from a gas-cooled high temperature nuclear reactor, provided with gas distributing pumps driven by steam-turbines. The system comprises means for generating a pressure signal of desired magnitude for the re-superheating portion, and means for providing a real pressure in the re-superheating portion, means (including a by-passing device) for generating steam-flow rate signal of desired magnitude, a turbine by-pass device comprising a by-pass tapping means for regulating the steam-flow-rate in said turbine according to the desired steam-flow rate signal and means for controlling said by-pass tapping means according to said desired steam-flow-rate signal [fr

Deliberate ignition of hydrogen-air-steam mixtures in condensing steam environments

International Nuclear Information System (INIS)

Blanchat, T.K.; Stamps, D.W.

1997-05-01

Large scale experiments were performed to determine the effectiveness of thermal glow plug igniters to burn hydrogen in a condensing steam environment due to the presence of water sprays. The experiments were designed to determine if a detonation or accelerated flame could occur in a hydrogen-air-steam mixture which was initially nonflammable due to steam dilution but was rendered flammable by rapid steam condensation due to water sprays. Eleven Hydrogen Igniter Tests were conducted in the test vessel. The vessel was instrumented with pressure transducers, thermocouple rakes, gas grab sample bottles, hydrogen microsensors, and cameras. The vessel contained two prototypic engineered systems: (1) a deliberate hydrogen ignition system and (2) a water spray system. Experiments were conducted under conditions scaled to be nearly prototypic of those expected in Advanced Light Water Reactors (such as the Combustion Engineering (CE) System 80+), with prototypic spray drop diameter, spray mass flux, steam condensation rates, hydrogen injection flow rates, and using the actual proposed plant igniters. The lack of any significant pressure increase during the majority of the burn and condensation events signified that localized, benign hydrogen deflagration(s) occurred with no significant pressure load on the containment vessel. Igniter location did not appear to be a factor in the open geometry. Initially stratified tests with a stoichiometric mixture in the top showed that the water spray effectively mixes the initially stratified atmosphere prior to the deflagration event. All tests demonstrated that thermal glow plugs ignite hydrogen-air-steam mixtures under conditions with water sprays near the flammability limits previously determined for hydrogen-air-steam mixtures under quiescent conditions. This report describes these experiments, gives experimental results, and provides interpretation of the results. 12 refs., 127 figs., 16 tabs

Type GQS-1 high pressure steam manifold water level monitoring system

International Nuclear Information System (INIS)

Li Nianzu; Li Beicheng; Jia Shengming

1993-10-01

The GQS-1 high pressure steam manifold water level monitoring system is an advanced nuclear gauge that is suitable for on-line detecting and monitor in high pressure steam manifold water level. The physical variable of water level is transformed into electrical pulses by the nuclear sensor. A computer is equipped for data acquisition, analysis and processing and the results are displayed on a 14 inch color monitor. In addition, a 4 ∼ 20 mA output current is used for the recording and regulation of water level. The main application of this gauge is for on-line measurement of high pressure steam manifold water level in fossil-fired power plant and other industries

Dynamic response of the EBR-II secondary sodium system to postulated leaks of steam and water into sodium

International Nuclear Information System (INIS)

Srinivas, S.; Chopra, P.S.; Stone, C.C.

1976-01-01

The paper presents evaluations of the dynamic response of a steam generator system to postulated leaks of steam and water into sodium. This work is part of a comprehensive fail-safe analysis of the EBR-II steam generator system

Heat supply of the town of Trnava from EBO nuclear plant

International Nuclear Information System (INIS)

Kovarik, Z.

4 variants of central heat supply from the V-2 Bohunice nuclear power plant were considered. Three included the supply of hot water while the fourth envisaged the supply of steam. The variants of hot water supply differed in the proportion of heat supply during load peak, the range being from 75% to 88% to 100%. The system suggested considers hot water with a maximum overpressure of 2.5 MPa and temperature of 150/70 degC, with possible temporary decrease to 130/70 degC. The estimated power of heat exchange stations is 240 MW at a temperature gradient of 150/70 degC and 180 MW at a temperature gradient 130/70 degC. The location, design and control of the heat supply system and the specifications of heat generation facilities are given. (J.P.)

Units 3 and 4 steam generators new water level control system

International Nuclear Information System (INIS)

Dragoev, D.; Genov, St.

2001-01-01

The Steam Generator Water Level Control System is one of the most important for the normal operation systems, related to the safety and reliability of the units. The main upgrading objective for the SG level and SGWLC System modernization is to assure an automatic maintaining of the SG level within acceptable limits (below protections and interlocks) from 0% to 100% of the power in normal operation conditions and in case of transients followed by disturbances in the SG controlled parameters - level, steam flow, feedwater flow and/or pressure/temperature. To achieve this objective, the computerized controllers of new SG water level control system follows current computer control technology and is implemented together with replacement of the feedwater control valves and the needed I and C equipment. (author)

Steam drum level dynamics in a multiple loop natural circulation system of a pressure-tube type boiling water reactor

International Nuclear Information System (INIS)

Jain, Vikas; Kulkarni, P.P.; Nayak, A.K.; Vijayan, P.K.; Saha, D.; Sinha, R.K.

2011-01-01

Highlights: → We have highlighted the problem of drum level dynamics in a multiple loop type NC system using RELAP5 code. → The need of interconnections in steam and liquid spaces close to drum is established. → The steam space interconnections equalize pressure and liquid space interconnections equalize level. → With this scheme, the system can withstand anomalous conditions. → However, the controller is found to be inevitable for inventory balance. - Abstract: Advanced Heavy Water Reactor (AHWR) is a pressure tube type boiling water reactor employing natural circulation as the mode of heat removal under all the operating conditions. Main heat transport system (MHTS) of AHWR is essentially a multi-loop natural circulation system with all the loops connected to each other. Each loop of MHTS has a steam drum that provides for gravity based steam-water separation. Steam drum level is a very critical parameter especially in multi-loop natural circulation systems as large departures from the set point may lead to ineffective separation of steam-water or may affect the driving head. However, such a system is susceptible to steam drum level anomalies under postulated asymmetrical operating conditions among the different quadrants of the core like feedwater flow distribution anomaly among the steam drums or power anomaly among the core quadrants. Analyses were carried out to probe such scenarios and unravel the underlying dynamics of steam drum level using system code RELAP5/Mod3.2. In addition, a scheme to obviate such problem in a passive manner without dependence on level controller was examined. It was concluded that steam drums need to be connected in the liquid as well as steam space to make the system tolerant to asymmetrical operating conditions.

System for measuring of air concentration in air-steam mixture during the transients

International Nuclear Information System (INIS)

Gorbenko, Gennady A.; Gakal, Pavlo G.; Epifanov, Konstantin S.; Osokin, Gennady V.; Smirnov, Sergey V.

2006-01-01

Description of system for air concentration measuring in air-steam mixture during the transients is represented. Air concentration measuring is based on discrete sampling method. The measuring system consists of sampler, transport pipeline, distributor and six measuring vessels. From the sampler air-steam mixture comes to distributor through transport pipeline and fills consecutively the measuring vessels. The true air concentration in place of measurement was defined based on measured air concentration in samples taken from measuring vessels. For this purpose, the mathematical model of transients in measuring system was developed. Air concentration transient in air-steam mixture in place of measurement was described in mathematical model by air concentration time-dependent function. The function parameters were defined based on air concentration measured in samples taken from measuring vessels. Estimated error of air concentration identification was about 10%. Measuring system was used in experiments on EREC BKV-213 test facility intended for testing of VVER-440/V-213 reactor barbotage-vacuum system

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

International Nuclear Information System (INIS)

Montero, Gisela

2006-01-01

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)

Functional performance of the helical coil steam generator, Consolidated Nuclear Steam Generator (CNSG) IV system. Executive summary report

International Nuclear Information System (INIS)

Watson, G.B.

1975-10-01

The objective of this project was to study the functional performance of the CNSG - IV helical steam generator to demonstrate that the generator meets steady-state and transient thermal-hydraulic performance specifications and that secondary flow instability will not be a problem. Economic success of the CNSG concepts depends to a great extent on minimizing the size of the steam generator and the reactor vessel for ship installation. Also, for marine application the system must meet stringent specifications for operating stability, transient response, and control. The full-size two-tube experimental unit differed from the CNSG only in the number of tubes and the mode of primary flow. In general, the functional performance test demonstrated that the helical steam generator concept will exceed the specified superheat of 35F at 100% load. The experimental measured superheat at comparable operating conditions was 95F. Testing also revealed that available computer codes accurately predict trends and overall performance characteristics

Innovation of blow-down system in steam generators of a VVER 440 unit

International Nuclear Information System (INIS)

Matal, O.; Simo, T.; Mancev, M.D.

1997-01-01

The impurities getting into the steam generator with the feedwater are continually removed by the blowdown and unit sludge system. The mostly non-symmetrical type of pipe branches under steam generators at WWER-440 units causes nonuniform blowdown flow rates at the halves of the steam generator; this often leads to a blocking of the pipe with the lower flow rate. The most simple way of hydraulically equalizing the blowdown pipes is to implement symmetric blowdown pipes and to install efficient throttling elements in the pipe. The proposed innovation will make it possible to re-distribute the blowdown flow rates and to reduce more effectively the concentrations of impurities in steam generators. (M.D.)

Wiring of leakage alarm of heating surface of modular steam generator with liquid metal, especially sodium

International Nuclear Information System (INIS)

Banovec, J.; Vytopil, O.

1980-01-01

Each module or module assembly forming a steam generator houses a water-sodium leak detector connected to an evaluation circuit via an amplifier. One amplifier and one evaluation unit are assigned to each module. The evaluation circuit output is connected to an output alarm unit. Each leak detector is also connected to the corresponding evaluation circuit via a reference standard signal supply. The detector systems, amplifiers and evaluation circuits have a common signal supply. (J.P.)

Coal lumps vs. electrons: How do Chinese bulk energy transport decisions affect the global steam coal market?

International Nuclear Information System (INIS)

Paulus, Moritz; Trüby, Johannes

2011-01-01

This paper demonstrates the ways in which different Chinese bulk energy transport strategies affect the future steam coal market in China and in the rest of the world. An increase in Chinese demand for steam coal will lead to a growing need for additional domestic infrastructure as production hubs and demand centers are spatially separated, and domestic transport costs could influence the future Chinese steam coal supply mix. If domestic transport capacity is available only at elevated costs, Chinese power generators could turn to the global trade markets and further increase steam coal imports. Increased Chinese imports could then yield significant changes in steam coal market economics on a global scale. This effect is analyzed in China, where coal is mainly transported by railway, and in another setting where coal energy is transported as electricity. For this purpose, a spatial equilibrium model for the global steam coal market has been developed. One major finding is that if coal is converted into electricity early in the supply chain, worldwide marginal costs of supply are lower than if coal is transported via railway. Furthermore, China's dependence on international imports is significantly reduced in this context. Allocation of welfare changes particularly in favor of Chinese consumers while rents of international producers decrease.

Dual Rate Adaptive Control for an Industrial Heat Supply Process Using Signal Compensation Approach

Energy Technology Data Exchange (ETDEWEB)

Chai, Tianyou; Jia, Yao; Wang, Hong; Su, Chun-Yi

2017-07-09

The industrial heat supply process (HSP) is a highly nonlinear cascaded process which uses a steam valve opening as its control input, the steam flow-rate as its inner loop output and the supply water temperature as its outer loop output. The relationship between the heat exchange rate and the model parameters, such as steam density, entropy, and fouling correction factor and heat exchange efficiency are unknown and nonlinear. Moreover, these model parameters vary in line with steam pressure, ambient temperature and the residuals caused by the quality variations of the circulation water. When the steam pressure and the ambient temperature are of high values and are subjected to frequent external random disturbances, the supply water temperature and the steam flow-rate would interact with each other and fluctuate a lot. This is also true when the process exhibits unknown characteristic variations of the process dynamics caused by the unexpected changes of the heat exchange residuals. As a result, it is difficult to control the supply water temperature and the rates of changes of steam flow-rate well inside their targeted ranges. In this paper, a novel compensation signal based dual rate adaptive controller is developed by representing the unknown variations of dynamics as unmodeled dynamics. In the proposed controller design, such a compensation signal is constructed and added onto the control signal obtained from the linear deterministic model based feedback control design. Such a compensation signal aims at eliminating the unmodeled dynamics and the rate of changes of the currently sample unmodeled dynamics. A successful industrial application is carried out, where it has been shown that both the supply water temperature and the rate of the changes of the steam flow-rate can be controlled well inside their targeted ranges when the process is subjected to unknown variations of its dynamics.

Development of an acoustic steam generator leak detection system using delay-and-sum beamformer

International Nuclear Information System (INIS)

Chikazawa, Yoshitaka

2009-01-01

A new acoustic steam generator leak detection system using delay-and-sum beamformer is proposed. The major advantage of the delay-and-sum beamformer is it could provide information of acoustic source direction. An acoustic source of a sodium-water reaction is supposed to be localized while the background noise of the steam generator operation is uniformly distributed in the steam generator tube region. Therefore the delay-and-sum beamformer could distinguish the acoustic source of the sodium-water reaction from steam generator background noise. In this paper, results from numerical analyses are provided to show fundamental feasibility of the new method. (author)

Design and development of steam generators for the AGR power stations at Heysham II/Torness

Energy Technology Data Exchange (ETDEWEB)

Charcharos, A N; Jones, A G [National Nuclear Corp. Ltd., Cheshire (United Kingdom)

1984-07-01

The current AGR steam generator design is a development of the successful once-through units supplied for the Oldbury Magnox and Hinkley/Hunterston AGR power stations. These units have demonstrated proven control and reliability in service. In this paper the factors which have dictated the design and layout of the latest AGR steam generators are described and reference made to the latest high temperature design techniques that have been employed. Details of development work to support the design and establish the performance characteristics over the range of plant operating conditions are also given. To comply with current UK safety standards, the AGR steam generators and associated plant are designed to accommodate seismic loadings. In addition, provision is made for an independent heat removal system for post reactor trip operations. (author)

Design and development of steam generators for the AGR power stations at Heysham II/Torness

International Nuclear Information System (INIS)

Charcharos, A.N.; Jones, A.G.

1984-01-01

The current AGR steam generator design is a development of the successful once-through units supplied for the Oldbury Magnox and Hinkley/Hunterston AGR power stations. These units have demonstrated proven control and reliability in service. In this paper the factors which have dictated the design and layout of the latest AGR steam generators are described and reference made to the latest high temperature design techniques that have been employed. Details of development work to support the design and establish the performance characteristics over the range of plant operating conditions are also given. To comply with current UK safety standards, the AGR steam generators and associated plant are designed to accommodate seismic loadings. In addition, provision is made for an independent heat removal system for post reactor trip operations. (author)

On line instrument systems for monitoring steam turbogenerators

Science.gov (United States)

Clapis, A.; Giorgetti, G.; Lapini, G. L.; Benanti, A.; Frigeri, C.; Gadda, E.; Mantino, E.

A computerized real time data acquisition and data processing for the diagnosis of malfunctioning of steam turbogenerator systems is described. Pressure, vibration and temperature measurements are continuously collected from standard or special sensors including startup or stop events. The architecture of the monitoring system is detailed. Examples of the graphics output are presented. It is shown that such a system allows accurate diagnosis and the possibility of creating a data bank to describe the dynamic characteristics of the machine park.

Simulation of main steam and feedwater system of full scope simulator for Qinshan 300 MW Nuclear Power Unit

International Nuclear Information System (INIS)

Zhao Xiaoyu

1996-01-01

The simulation of main steam and feedwater system is the most important and maximal part in secondary circuit model, including all of main steam and feedwater's thermal-hydraulic properties, except heat-exchange of secondary side of steam generator. It simulates main steam header, steam power in each stage of turbine, moisture separator-reheater, deaerator, condenser, high pressure and low pressure heater, auxiliary feedwater and main steam bypass in full scope

Will the Steam Coal Price Rebound under the New Economy Normalcy in China?

Directory of Open Access Journals (Sweden)

Xiaopeng Guo

2016-09-01

Full Text Available The steam coal price in China has been continuously decreasing since the second half of 2012. Constant low price of coal will accelerate the development of thermal power, cause more serious air pollution problems, and bring adverse influence to China’s energy reformation in the future. Therefore, analyzing the factors underlying the phenomenon of the decreasing steam coal price is significant. In this study, we first qualitatively analyze five main factors, namely, economy, supply, demand, substitutes, and port stocks. On the basis of the relationships among these five factors, we obtain the causality diagram and the system flow diagram of coal price for further quantitative research. Then, we conduct an empirical analysis using the system dynamics (SD method and determine the simulated price from 2012 to 2017. Finally, we discuss the running results and come to the conclusion that the steam coal price will continue to decrease under the combined actions of the five main factors and it will not rebound in the near future.

Steam separator-superheater with drawing of a fraction of the dried steam

International Nuclear Information System (INIS)

Bessouat, Roger; Marjollet, Jacques.

1976-01-01

This invention concerns a vertical separator-superheater of the steam from a high pressure expansion turbine before it is admitted to an expansion turbine at a lower pressure, by heat exchange with steam under a greater pressure, and drawing of a fraction of the dried steam before it is superheated. Such drawing off is necessary in the heat exchange systems of light water nuclear reactors. Its purpose is to provide a separator-superheater that provides an even flow of non superheated steam and a regular distribution of the steam to be superheated to the various superheating bundles, with a significantly uniform temperature of the casing, thereby preventing thermal stresses and ensuring a minimal pressure drop. The vertical separator-superheater of the invention is divided into several vertical sections comprising as from the central area, a separation area of the steam entrained water and a superheater area and at least one other vertical section with only a separation area of the steam entrained water [fr

Requalification of the steam supply systems of Units 3 and 4 of the Kozloduy NPP to a new model WWER-440/B-209M

International Nuclear Information System (INIS)

Iordanov, I.; Ourutchev, V.; Stoev, M.; Sabinov, S.

2001-01-01

In order to achieve significant advances in operational safety level, the project characteristics, the possibility of safety systems upgrading and operational conditions of Units 1 to 4 of the Kozloduy NPP were an object of very serious and in-depth analysis in the years 1990-2000. This systematic evaluation was initiated under the broad international concern resulted from the conclusions of IAEA missions held during 1990-1991 to assess the safety of the units. As a result of the efforts of the plant staff and many international experts the operational conditions, design safety and plant management were dramatically improved which resulted in bringing the plant to a new safety level. This review also developed such that the design safety features of Units 3 and 4 are significantly different from those units of the so-called V-230 group. The principle difference and advantages of Units 3 and 4 design were clarified and confirmed. A review process of the changed status of Units 3 and 4 safety was conducted in 1999-2000 with the help of IAEA experts and the experts of RISKAUDIT and WENRA. The process led to the conclusion that the significance of advantages of the safety level need to be encapsulated within a new safety case and the corresponding set of steps was combined as a 'Project for upgrading the Nuclear Steam Supply System of Units 3 and 4 of Kozloduy NPP to model WWER-440/B-209M'. The completion of the activities under this project is expected in 2002 following the major implementation phase during 2001/2002 units' outages. (author)

Economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry

Directory of Open Access Journals (Sweden)

Flavia Melo Menezes

2017-12-01

Full Text Available The burning of fossil fuels majorly contributes to the increase in global warming, and it represents 93% of greenhouse gases emissions in the chemical industry. Most of the energy demand in this sector is associated with steam systems, where 1/3 of the energy efficiency opportunities are located in its distribution system. However, most of the literature focuses on the design of new systems. Those that deal with existing systems, not always use simple and available methods. Furthermore, they address energy losses of steam systems only due to thermal insulation, ignoring those due to leakages of traps. Given this context, the purpose of this paper is to determine the economic feasibility of an energy efficiency project for a steam distribution system in a chemical industry, located in the metropolitan region of Salvador, Brazil. First, the energy lost in the steam distribution system through heat insulation and steam traps was estimated by applying thermodynamic principles, and technic consulting, respectively. Then, investments were estimated using commercial prices for new thermal insulation and steam traps. Finally, an economic evaluation of the improvement project was made, through the construction of a cash flow, and calculation of economic indicators: payback time, net present value (NPV, and internal rate of return (IRR. Economic indicators showed that the project is economically viable. The NPV and IRR reached approximately 5 million reais, and 66% per year, respectively. Additionally, this project also had social and environmental benefits, such as a reduction in greenhouse gases emissions, and increased local water availability.

Measure Guideline: Steam System Balancing and Tuning for Multifamily Residential Buildings

Energy Technology Data Exchange (ETDEWEB)

Choi, J.; Ludwig, P.; Brand, L.

2013-04-01

This report was written as a resource for professionals involved in multifamily audits, retrofit delivery, and program design, as well as for building owners and contractors. It is intended to serve as a guide for those looking to evaluate and improve the efficiency and operation of one-pipe steam heating systems. In centrally heated multifamily buildings with steam or hydronic systems, the cost of heat for tenants is typically absorbed into the owner's operating costs. Highly variable and rising energy costs have placed a heavy burden on landlords. In the absence of well-designed and relevant efficiency efforts, increased operating costs would be passed on to tenants who often cannot afford those increases. Misinvestment is a common problem with older heating systems -- multiple contractors may inadequately or inappropriately upgrade parts of systems and reduce system functionality and efficiency, or the system has not been properly maintained.

The development of a control system for a small high speed steam microturbine generator system

Science.gov (United States)

Alford, A.; Nichol, P.; Saunders, M.; Frisby, B.

2015-08-01

Steam is a widely used energy source. In many situations steam is generated at high pressures and then reduced in pressure through control valves before reaching point of use. An opportunity was identified to convert some of the energy at the point of pressure reduction into electricity. To take advantage of a market identified for small scale systems, a microturbine generator was designed based on a small high speed turbo machine. This machine was packaged with the necessary control valves and systems to allow connection of the machine to the grid. Traditional machines vary the speed of the generator to match the grid frequency. This was not possible due to the high speed of this machine. The characteristics of the rotating unit had to be understood to allow a control that allowed export of energy at the right frequency to the grid under the widest possible range of steam conditions. A further goal of the control system was to maximise the efficiency of generation under all conditions. A further complication was to provide adequate protection for the rotating unit in the event of the loss of connection to the grid. The system to meet these challenges is outlined with the solutions employed and tested for this application.

Alteration of biomacromolecule in corn by steam flaking in relation to biodegradation kinetics in ruminant, revealed with vibrational molecular spectroscopy.

Science.gov (United States)

Xu, Ningning; Liu, Jianxin; Yu, Peiqiang

2018-02-15

Large scale of steam flaked corn has been used in dairy ration to maintain high milk production level. This study aimed to determine effects of steam flaking on processing-induced intrinsic molecular structure changes that were associated with rumen degradation kinetics and nutrients supply. The advanced vibrational molecular spectroscopy was applied to reveal the processing-induced intrinsic structure changes on a molecular basis. The rumen degradation kinetics and nutrient supply were determined using in situ approach in ruminant livestock system. Raw corn grain (RC) and steam flaked corn grain (SFC) were obtained from two different processing plants. The results showed that (1) Compared to RC, SFC had greater truly digestible non-fiber carbohydrate [tdNFC: 86.8 versus 78.0% dry matter (DM)], but lower truly digestible crude protein [tdCP: 7.7 versus 9.0% DM]. (2) The steam flaking increased (PMolecular absorbance intensities of most carbohydrate biopolymers were greater in SFC (Pmolecular spectral intensities were lower (Pmolecular structure and nutrient interactive study showed that carbohydrate spectral intensities were positively (Pmolecular structure changes had an interactive relationship with rumen degradation kinetics. Copyright © 2017 Elsevier B.V. All rights reserved.

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

International Nuclear Information System (INIS)

Lee, Yong Bum; Lee, Jong Jik

2016-01-01

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Bum; Lee, Jong Jik [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2016-06-15

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

Conditions for microbial growth in the FILTRA steam absorption tower

International Nuclear Information System (INIS)

Nilsson, H.; Roffey, R.

1983-08-01

By the appointment of the Southern Sweden Power Supply an experimental study has been carried out in order to evaluate the risk for microbial growth in the planned FILTRA steam absorbtion tower at the nuclear power plant in Barsebaeck. Four modelsystems were supplied with nitrogen atmosphere and a relative humidity of 100, 75, 50 and 25 percent. The fifth system received air and 75 percent relative humidity. Samples were collected and analysed for microbial growth after 1, 2, 4 and 8 months. The amounts of microorganisms and the ATP content was monitored. No measureable growth of any significance could be observed after 8 months in any system. An elementary analyses showed that the level of nitrogen and carbon in the stones was below the limit of detection (<0.3 percent C, <0.2 percent N). (author)

Design of the steam generator in an energy conversion system based on the aluminum combustion with water

International Nuclear Information System (INIS)

Mercati, Stefano; Milani, Massimo; Montorsi, Luca; Paltrinieri, Fabrizio

2012-01-01

Highlights: ► Development of a numerical approach for the analysis of a co-generation system based on the aluminum water reaction. ► Construction of system operating maps for estimating the system behavior. ► Comparison of two different designs of the steam generator for the system. ► Definition of the operating range where each configuration provides the best performance. -- Abstract: The paper shows the preliminary design of the superheated steam generator to be used in a novel hydrogen production and energy conversion system based on the combustion of aluminum particles with water. The system is aimed at producing hydrogen and pressurized superheated steam, using the heat released by the Al–H 2 O reaction. The interest on this type of technology arises because of the possibility of obtaining hydrogen with very low pollutant and greenhouse gas emissions, compared to the traditional hydrogen production systems, such as the steam reforming from methane. The analysis of the combustion chamber and the heat recovery system is carried out by means of a lumped and distributed parameter numerical approach. The multi phase and gas mixture theoretical principles are used both to characterize the mass flow rate and the heat release in the combustion chamber and within the heat exchangers in order to relate the steam generator performance to the system operating parameters. Finally, the influence of the steam generator performance on the whole energy conversion system behavior is addressed, with particular care to the evaluation of the total power and efficiency variation with the combustion parameters.

Some engineering aspects of the steam generator system for the United States LMFBR demonstration plant

International Nuclear Information System (INIS)

Tippets, F.E.

1975-01-01

This paper describes the main design features of the steam generator system for the Clinch River Breeder Reactor Plant and the engineering approach being employed for some of the critical elements of this system, including in particular the sodium-steam/water boundary, the efforts to have this boundary be of highest integrity, and the system features to safely accommodate any failure of the boundary. (author)

Some engineering aspects of the steam generator system for the United States LMFBR demonstration plant

Energy Technology Data Exchange (ETDEWEB)

Tippets, F E

1975-07-01

This paper describes the main design features of the steam generator system for the Clinch River Breeder Reactor Plant and the engineering approach being employed for some of the critical elements of this system, including in particular the sodium-steam/water boundary, the efforts to have this boundary be of highest integrity, and the system features to safely accommodate any failure of the boundary. (author)

The effect of steam separataor efficiency on transient following a steam line break

International Nuclear Information System (INIS)

Choi, J.H.; Ohn, M.Y.; Lee, N.H.; Hwang, S.T.; Lee, S.K.

1996-01-01

Detailed thermalhydraulic simulations for CANDU 6 steam line break inside containment are performed to predict the response of the primary and secondary circuits. The analysis is performed using the thermalhydraulic computer code, CATHENA, with a coupled primary and secondary circuit model. A two-loop representation of the primary and secondary circuits is modelled. The secondary circuit model includes the feedwater line from the deaerator storage tank, multi-node steam generators and the steam line up to the turbine. Two cases were carried out using different assumptions for the efficiency of the steam separators. Case 1 assumes the efficiency of the steam separators becomes zero when the water level in the steam drum increases to the elevation of primary cyclones, or the outlet flow from the steam generator becomes higher than 150 % of normal flow. Case 2 assumes the efficiency becomes zero only when the water level in the steam drum reaches the elevation of primary cyclones. The simulation results show that system responses are sensitive to the assumption for the efficiency of the steam separators and case 1 gives higher discharge energy. Fuel cooling is assured, since primary circuit is cooled down sufficiently by the steam generators for both cases. (author)

Risk-based and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, K.; Nagai, S.; Akikuni, Y.; Fujiwara, T.; Furuya, K.; Matsumoto, S.; Takagi, K.; Kawabata, T.

2003-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants. (orig.)

CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

International Nuclear Information System (INIS)

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb; Jacqueline G. Broder

2002-01-01

The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates were completed and issued. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility hydrolysis production has been completed to produce lignin for co-fire testing and the lignin fuel was washed and dewatered. Both the lignin and bio-solids fuel materials for co-fire testing were sent to the co-fire facility (EERC) for evaluation and co-firing. EERC has received coal typical of the fuel to the TVA-Colbert boilers. This material was used at EERC as baseline material and for mixing with the bio-fuel for combustion testing. All the combustion and fuel handling tests at EERC have been completed. During fuel preparation EERC reported no difficulties in fuel blending and handling. Preliminary co-fire test results indicate that the blending of lignin and bio-solids with the Colbert coal blend generally reduces NO(sub x) emissions, increases the reactivity of the coal, and increases the ash deposition rate on superheater surfaces. Deposits produced from the fuel blends, however, are more friable and hence easier to remove from tube surfaces relative to those produced from the baseline Colbert coal blend. The final co-fire testing report is being prepared at EERC and will be completed by the end of the second quarter of 2002. The TVA-Colbert facility has neared completion of the task to evaluate co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system have been

AC power supply systems

International Nuclear Information System (INIS)

Law, H.

1987-01-01

An ac power supply system includes a rectifier fed by a normal ac supply, and an inverter connected to the rectifier by a dc link, the inverter being effective to invert the dc output of the receiver at a required frequency to provide an ac output. A dc backup power supply of lower voltage than the normal dc output of the rectifier is connected across the dc link such that the ac output of the rectifier is derived from the backup supply if the voltage of the output of the inverter falls below that of the backup supply. The dc backup power may be derived from a backup ac supply. Use in pumping coolant in nuclear reactor is envisaged. (author)

PMK-2. Experimental study on steam generator behaviour

Energy Technology Data Exchange (ETDEWEB)

Ezsoel, G.; Szabados, L.; Trosztel, I. [KFKI Atomic Energy Research Inst., Budabest (Hungary)

1995-12-31

The PMK-2 is a full pressure scaled-down model of the Paks Nuclear Power Plant, with a 1:2070 scaling ratio for the volume and power. It has a steam generator model which is a vertical section of the horizontal steam generator. The model has hot and cold collectors similarly to the steam generators of the plant. The heat transfer tubes are horizontal tubes. There are 82 rows of tubes and the elevations, as well as the heat transfer surface distribution is the same as in the plant. The elevation of the feed water supply is similar to that of the plant. To study the temperature distribution in both the primary and the secondary side several thermocouples are built in, in addition to the overall instrumentation of the loop which has again a high number of measurement channels. Paper gives a description and results of SPE-4, with special respect to the steam generator behaviour in both steady state and transient conditions. Axial distribution of coolant and feedwater temperatures are given for the primary and the secondary side of hot and cold collectors and the temperature distribution in the centre of steam generator. (orig.).

PMK-2. Experimental study on steam generator behaviour

Energy Technology Data Exchange (ETDEWEB)

Ezsoel, G; Szabados, L; Trosztel, I [KFKI Atomic Energy Research Inst., Budabest (Hungary)

1996-12-31

The PMK-2 is a full pressure scaled-down model of the Paks Nuclear Power Plant, with a 1:2070 scaling ratio for the volume and power. It has a steam generator model which is a vertical section of the horizontal steam generator. The model has hot and cold collectors similarly to the steam generators of the plant. The heat transfer tubes are horizontal tubes. There are 82 rows of tubes and the elevations, as well as the heat transfer surface distribution is the same as in the plant. The elevation of the feed water supply is similar to that of the plant. To study the temperature distribution in both the primary and the secondary side several thermocouples are built in, in addition to the overall instrumentation of the loop which has again a high number of measurement channels. Paper gives a description and results of SPE-4, with special respect to the steam generator behaviour in both steady state and transient conditions. Axial distribution of coolant and feedwater temperatures are given for the primary and the secondary side of hot and cold collectors and the temperature distribution in the centre of steam generator. (orig.).

Preliminary design of steam reformer in out-pile demonstration test facility for HTTR heat utilization system

Energy Technology Data Exchange (ETDEWEB)

Haga, Katsuhiro; Hino, Ryutaro; Inagaki, Yosiyuki; Hata, Kazuhiko; Aita, Hideki; Sekita, Kenji; Nishihara, Tetsuo; Sudo, Yukio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Yamada, Seiya

1996-11-01

One of the key objectives of HTTR is to demonstrate effectiveness of high-temperature nuclear heat utilization system. Prior to connecting a heat utilization system to HTTR, an out-pile demonstration test is indispensable for the development of experimental apparatuses, operational control and safety technology, and verification of the analysis code of safety assessment. For the first heat utilization system of HTTR, design of the hydrogen production system by steam reforming is going on. We have proposed the out-pile demonstration test plan of the heat utilization system and conducted preliminary design of the test facility. In this report, design of the steam reformer, which is the principal component of the test facility, is described. In the course of the design, two types of reformers are considered. The one reformer contains three reactor tubes and the other contains one reactor tube to reduce the construction cost of the test facility. We have selected the steam reformer operational conditions and structural specifications by analyzing the steam reforming characteristics and component structural strength for each type of reformer. (author)

Hydrogen production by high-temperature electrolysis of water vapor steam. Test results obtained with an electrolysis tube

International Nuclear Information System (INIS)

Hino, Ryutaro; Miyamoto, Yoshiaki

1995-01-01

High-temperature electrolysis of water vapor steam is an advanced hydrogen production process decomposing high temperature steam up to 1,000degC, which applies an electro-chemical reaction reverse to the solid oxide fuel cell. At Japan Atomic Energy Research Institute, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 electrolysis cells in order to develop heat utilization systems for high-temperature gas-cooled reactors. The electrolysis cells of which electrolyte was yttria-stabilized zirconia were formed on a porous ceramic tube in series by plasma spraying. In the experiments, water steam mixed with argon carrier gas was supplied into the electrolysis tube heated at a constant temperature regulated in the range from 850degC to 950degC, and electrolysis power was supplied by a DC power source. Hydrogen production rate increased with applied voltage and electrolysis temperature; the maximum production rate was 6.9Nl/h at 950degC. Hydrogen production rate was correlated with applied current densities on the basis of experimental data. High energy efficiency was achieved under the applied current density ranging from 80 to 100 mA/cm 2 . (author)

Evaluation of steam generator U-tube integrity during PWR station blackout with secondary system depressurization

International Nuclear Information System (INIS)

Hidaka, Akihide; Asaka, Hideaki; Sugimoto, Jun; Ueno, Shingo; Yoshino, Takehito

1999-12-01

In PWR severe accidents such as station blackout, the integrity of steam generator U-tube would be threatened early at the transient among the pipes of primary system. This is due to the hot leg countercurrent natural circulation (CCNC) flow which delivers the decay heat of the core to the structures of primary system if the core temperature increases after the secondary system depressurization. From a view point of accident mitigation, this steam generator tube rupture (SGTR) is not preferable because it results in the direct release of primary coolant including fission products (FP) to the environment. Recent SCDAP/RELAP5 analyses by USNRC showed that the creep failure of pressurizer surge line which results in release of the coolant into containment would occur earlier than SGTR during the secondary system depressurization. However, the analyses did not consider the decay heat from deposited FP on the steam generator U-tube surface. In order to investigate the effect of decay heat on the steam generator U-tube integrity, the hot leg CCNC flow model used in the USNRC's calculation was, at first, validated through the analysis for JAERI's LSTF experiment. The CCNC model reproduced well the thermohydraulics observed in the LSTF experiment and thus the model is mostly reliable. An analytical study was then performed with SCDAP/RELAP5 for TMLB' sequence of Surry plant with and without secondary system depressurization. The decay heat from deposited FP was calculated by JAERI's FP aerosol behavior analysis code, ART. The ART analysis showed that relatively large amount of FPs may deposit on steam generator U-tube inlet mainly by thermophoresis. The SCDAP/RELAP5 analyses considering the FP decay heat predicted small safety margin for steam generator U-tube integrity during secondary system depressurization. Considering associated uncertainties in the analyses, the potential for SGTR cannot be ignored. Accordingly, this should be considered in the evaluation of merits

Electric power system / emergency power supply

International Nuclear Information System (INIS)

Dorn, P.G.

1980-01-01

One factor of reliability of reactor safety systems is the integrity of the power supply. The purpose of this paper is a review and a discussion of the safety objectives required for the planning, licensing, manufacture and erection of electrical power systems and components. The safety aspects and the technical background of the systems for - the electric auxiliary power supply system and - the emergency power supply system are outlined. These requirements result specially from the safety standards which are the framework for the studies of safety analysis. The overall and specific requirements for the electrical power supply of the safety systems are demonstrated on a 1300 MW standard nuclear power station with a pressurized water reactor. (orig.)

ORCENT-2, Full Load Steam Turbine Cycle Thermodynamics for LWR Power Plant

International Nuclear Information System (INIS)

Fuller, L.C.

1979-01-01

1 - Description of problem or function: ORCENT-2 performs heat and mass balance 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. The program handles both condensing and back-pressure turbine exhaust arrangements. Turbine performance calculations are based on the General Electric Company method for 1800-rpm large steam turbine- generators operating with light-water-cooled nuclear reactors. Output includes all information normally shown on a turbine-cycle heat balance diagram. 2 - Method of solution: The turbine performance calculations follow the procedures outlined in General Electric report GET-6020. ORCENT-2 utilizes the 1967 American Society of Mechanical Engineers (ASME) formulations and procedures for calculating the properties of steam, adapted for ORNL use by D.W. Altom. 3 - Restrictions on the complexity of the problem: Maxima of: 12 feed-water heaters, 5 moisture removal stages in the low-pressure turbine section. ORCENT-2 is limited to 1800-rpm tandem-compound turbine-generators with single- or double-flow high pressure sections and one, two, or three double-flow low-pressure turbine sections. Steam supply for LWR cycles should be between 900 and 1100 psia and slightly wet to 100 degrees F of initial superheat. Generator rating should be greater than 100 MVA

Erosion corrosion in wet steam

International Nuclear Information System (INIS)

Tavast, J.

1988-03-01

The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

Effects of non-condensable gas on the condensation of steam

International Nuclear Information System (INIS)

Jackson, J.D.; An, P.; Reinert, A.; Ahmadinejad, M.

2000-01-01

The experimental work reported here was undertaken with the aim of extending the database currently available on the condensation of steam in the presence of non-condensable gases and thereby improving the empirical input to thermal-hydraulic codes which might be used for design and safety assessment of advanced water-cooled nuclear reactors. Heat was removed from flowing mixtures of steam and air in a test section by means of a water-cooled condensing plate. The test facility constructed for the study incorporates a degassing unit which supplies water to a boiler. This delivers steam steadily to a mixing chamber where it joins with a flow of preheated air. The mixture of steam and air is supplied to the bottom of a cylindrical test section in which it flows upwards over a double sided condensing plate which can be vertical, inclined or horizontal, The rate at which heat is removed by cooling water flowing through internal passages in the plate can de determined calorimetrically knowing the flow rate of the water and its temperature rise. After commissioning experiments had shown that reliable measurements of condensation heat transfer rate could be made using the test facility, a programme of development work followed in the course of which three different designs of condensing plate were evaluated in turn. The version eventually used in the main programme of experiments which followed was made from copper. However, its surfaces were coated with a thin layer of nickel and then with one of chromium. It was found that such a surface consistently promoted dropwise condensation and showed no signs of deterioration after lengthy periods of use. The rate of heat removal from pure steam and from mixtures of steam and air in varying proportions was measured as a function of plate sub-cooling for a variety of plate orientations. (author)

Coal fired steam generation for heavy oil recovery

International Nuclear Information System (INIS)

Firmin, K.

1992-01-01

In Alberta, some 21,000 m 3 /d of heavy oil and bitumen are produced by in-situ recovery methods involving steam injection. The steam generation requirement is met by standardized natural-gas-fired steam generators. While gas is in plentiful supply in Alberta and therefore competitively priced, significant gas price increases could occur in the future. A 1985 study investigating the alternatives to natural gas as a fuel for steam generation concluded that coal was the most economic alternative, as reserves of subbituminous coal are not only abundant in Alberta but also located relatively close to heavy oil and bitumen production areas. The environmental performance of coal is critical to its acceptance as an alternate fuel to natural gas, and proposed steam generator designs which could burn Alberta coal and control emissions satisfactorily are assessed. Considerations for ash removal, sulfur dioxide sorption, nitrogen oxides control, and particulate emission capture are also presented. A multi-stage slagging type of coal-fired combustor has been developed which is suitable for application with oilfield steam generators and is being commissioned for a demonstration project at the Cold Lake deposit. An economic study showed that the use of coal for steam generation in heavy oil in-situ projects in the Peace River and Cold Lake areas would be economic, compared to natural gas, at fuel price projections and design/cost premises for a project timing in the mid-1990s. 7 figs., 3 tabs

Design of a partial inter-tube lancing system actuated by hydraulic power for type F model steam generator in nuclear power plant

International Nuclear Information System (INIS)

Kim, S. T.; Jeong, W. T.

2008-01-01

The sludge grown up in steam generators of nuclear power plants shortens the life-cycle of steam generators and reduces the output of power plants. So KHNP(Korea Hydro and Nuclear Power), the only nuclear power utility in Korea, removes it periodically using a steam generator lancing system during the outage of plants for an overhaul. KEPRI(Korea Electric Power Research Institute) has developed lancing systems with high pressured water nozzle for steam generators of nuclear power plants since 2001. In this paper, the design of a partial inter-tube lancing system for model F type steam generators will be described. The system is actuated without a DC motor inner steam generators because the motors in a steam generator make a trouble from high intensity of radioactivity as a break down

Steam plant for pressurized water reactors

International Nuclear Information System (INIS)

Anon.

1983-01-01

This book discusses the research and development organisations and users to highlight those aspects of the steam turbine and associated plant which are particularly related to the PWR system. The contents include: Characteristics of the steam system (including feed train, dump system and safety aspects); overall design aspects of high and half speed turbines; design aspects of the steam generator and seismic considerations; moisture separators and reheaters; feed pumps and their drives; water treatment; safety related valves; operational experience; availability and performance

EPRI steam generator programs

International Nuclear Information System (INIS)

Martel, L.J.; Passell, T.O.; Bryant, P.E.C.; Rentler, R.M.

1977-01-01

The paper describes the current overall EPRI steam generator program plan and some of the ongoing projects. Because of the recent occurrence of a corrosion phenomenon called ''denting,'' which has affected a number of operating utilities, an expanded program plan is being developed which addresses the broad and urgent needs required to achieve improved steam generator reliability. The goal of improved steam generator reliability will require advances in various technologies and also a management philosophy that encourages conscientious efforts to apply the improved technologies to the design, procurement, and operation of plant systems and components that affect the full life reliability of steam generators

Research on structural integration of thermodynamic system for double reheat coal-fired unit with CO2 capture

Science.gov (United States)

Wang, Lanjing; Shao, Wenjing; Wang, Zhiyue; Fu, Wenfeng; Zhao, Wensheng

2018-02-01

Taking the MEA chemical absorption carbon capture system with 85% of the carbon capture rate of a 660MW ultra-super critical unit as an example,this paper puts forward a new type of turbine which dedicated to supply steam to carbon capture system. The comparison of the thermal systems of the power plant under different steam supply schemes by using the EBSILON indicated optimal extraction scheme for Steam Extraction System in Carbon Capture System. The results show that the cycle heat efficiency of the unit introduced carbon capture turbine system is higher than that of the usual scheme without it. With the introduction of the carbon capture turbine, the scheme which extracted steam from high pressure cylinder’ s steam input point shows the highest cycle thermal efficiency. Its indexes are superior to other scheme, and more suitable for existing coal-fired power plant integrated post combustion carbon dioxide capture system.

Combined heat and power considered as a virtual steam cycle heat pump

International Nuclear Information System (INIS)

Lowe, Robert

2011-01-01

The first aim of this paper is to shed light on the thermodynamic reasons for the practical pursuit of low temperature operation by engineers involved in the design and the operation of combined heat and power (CHP) and district heating (DH) systems. The paper shows that the steam cycle of a combined heat and power generator is thermodynamically equivalent to a conventional steam cycle generator plus an additional virtual steam cycle heat pump. This apparently novel conceptualisation leads directly to (i) the observed sensitivity of coefficient of performance of CHP to supply and return temperatures in associated DH systems, and (ii) the conclusion that the performance of CHP will tend to be significantly higher than real heat pumps operating at similar temperatures. The second aim, which is pursued more qualitatively, is to show that the thermodynamic performance advantages of CHP are consistent with the goal of deep, long-term decarbonisation of industrialised economies. As an example, estimates are presented, which suggest that CHP based on combined-cycle gas turbines with carbon capture and storage has the potential to reduce the carbon intensity of delivered heat by a factor of ∼30, compared with a base case of natural gas-fired condensing boilers. - Highlights: → Large-scale CHP systems are thermodynamically equivalent to virtual steam cycle heat pumps. → COPs of such virtual heat pumps are necessarily better than the Carnot limit for real heat pumps. → COPs can approach 9 for plant matched to district heating systems with flow temperatures of 90 deg. C. → CHP combined with CCGT and CCS can reduce the carbon intensity of delivered heat ∼30-fold.

Computerized operating cost model for industrial steam generation

Energy Technology Data Exchange (ETDEWEB)

Powers, T.D.

1983-02-01

Pending EPA regulations, establishing revised emission levels for industrial boilers are perceived to have an effect on the relative costs of steam production technologies. To aid in the comparison of competitive boiler technologies, the Steam Cost Code was developed which provides levelized steam costs reflecting the effects of a number of key steam cost parameters. The Steam Cost Code is a user interactive FORTRAN program designed to operate on a VAX computer system. The program requires the user to input a number of variables describing the design characteristics, capital costs, and operating conditions for a specific boiler system. Part of the input to the Steam Cost Code is the capital cost of the steam production system. The capital cost is obtained from a program called INDCEPT, developed by Oak Ridge National Laboratory under Department of Energy, Morgantown Energy Technology Center sponsorship.

Supply Chain Systems Architecture and Engineering Design: Green-field Supply Chain Integration

OpenAIRE

Radanliev, P

2015-01-01

This paper developed a new theory for supply chain architecture, and engineering design that enables integration of the business and supply chain strategies. The architecture starts with individual supply chain participants and derives insights into the complex and abstract concept of green-field integration design. The paper presented a conceptual system for depicting the interactions between business and supply chain strategy engineering. The system examines the decisions made when engineer...

Reconstruction of Low Pressure Gas Supply System

Directory of Open Access Journals (Sweden)

S. N. Osipov

2013-01-01

Full Text Available The current reconstruction of residential areas in large cities especially with the developed heat-supply systems from thermal power stations and reduction of heat consumption for heating due to higher thermal resistance of building enclosing structures requires new technical solutions in respect of gas-supply problems. While making reconstruction of a gas-supply system of the modernized or new buildings in the operating zone of one gas-distribution plant it is necessary to change hot water-supply systems from gas direct-flow water heaters to centralized heat-supply and free gas volumes are to be used for other needs or gas-supply of new buildings with the current external gas distribution network.Selection of additional gas-line sections and points of gas-supply systems pertaining to new and reconstructed buildings for their connection to the current distribution system of gas-supply is to be executed in accordance with the presented methodology.

An integrated leak detection system for the ALMR steam generator

International Nuclear Information System (INIS)

Dayal, Y.; Gaubatz, D.C.; Wong, K.K.; Greene, D.A.

1995-01-01

The steam generator (SG) of the Advanced Liquid Metal Reactor (ALMR) system serves as a heat exchanger between the shell side secondary loop hot liquid sodium and the tube side water/steam mixture. A leak in the tube will result in the injection of the higher pressure water/steam into the sodium and cause an exothermic sodium-water reaction. An initial small leak (less than 1 gm/sec) can escalate into an intermediate size leak in a relatively short time by self enlargement of the original flaw and by initiating leaks in neighboring tubes. If not stopped, complete rupture of one or more tubes can cause injection rates of thousands of gm/sec and result in the over pressurization of the secondary loop rupture disk and dumping of the sodium to relieve pressure. The down time associated with severe sodium-water reaction damage has great adverse economic consequence. An integrated leak detection system (ILDS) has been developed which utilizes both chemical and acoustic sensors for improved leak detection. The system provides SG leak status to the reactor operator and is reliable enough to trigger automatic control action to protect the SG. The ILDS chemical subsystem uses conventional in-sodium and cover gas hydrogen detectors and incorporates knowledge based effects due to process parameters for improved reliability. The ILDS acoustic subsystem uses an array of acoustic sensors and incorporates acoustic beamforming technology for highly reliable and accurate leak identification and location. The new ILDS combines the small leak detection capability of the chemical system with the reliability and rapid detection/location capability of the acoustic system to provide a significantly improved level of protection for the SG over a wide range of operation conditions. (author)

Using the artificial neural network to control the steam turbine heating process

International Nuclear Information System (INIS)

Nowak, Grzegorz; Rusin, Andrzej

2016-01-01

Highlights: • Inverse Artificial Neural Network has a potential to control the start-up process of a steam turbine. • Two serial neural networks made it possible to model the rotor stress based of steam parameters. • An ANN with feedback enables transient stress modelling with good accuracy. - Abstract: Due to the significant share of renewable energy sources (RES) – wind farms in particular – in the power sector of many countries, power generation systems become sensitive to variable weather conditions. Under unfavourable changes in weather, ensuring required energy supplies involves hasty start-ups of conventional steam power units whose operation should be characterized by higher and higher flexibility. Controlling the process of power engineering machinery operation requires fast predictive models that will make it possible to analyse many parallel scenarios and select the most favourable one. This approach is employed by the algorithm for the inverse neural network control presented in this paper. Based on the current thermal state of the turbine casing, the algorithm controls the steam temperature at the turbine inlet to keep both the start-up rate and the safety of the machine at the allowable level. The method used herein is based on two artificial neural networks (ANN) working in series.

ON THE ISSUE OF RATIONAL ORGANIZATION OF THE TEXTILE AND KNITWEAR ENTERPRISES HEAT AND POWER SUPPLY SYSTEM

Directory of Open Access Journals (Sweden)

V. N. Romaniuk

2016-01-01

Full Text Available The paper considers organization of the industrial enterprise heat and power supply system (HPSS, to be rational from the structure and flow parameter standpoint. Developing HPSS is one of the main lines of implementing energy-saving potential in volumes complying with dictates of the time on reducing the production cost energy component, which is especially vital for the light industry enterprises of Belarus. To reduce the complexity of the task the authors employ the hierarchical structure of HPSS. With regard to textile and knitwear enterprises, they show the irregularity of energy supply on the one hand, and of energy use on the other. The finishing departments of the specified enterprises ensure their thermo-technological status. It is proverbial that accomplished in terms of energy thermo-technological enterprises should not consume the electric energy produced in condensation electric power plants. Instead, for their production needs, they should use thermal energy and electricity generated in the CHP. At the same time, steam turbine CHPs of low power, and consequently of low initial parameters, cannot provide the required electrical and heat energy flow generation balance. The indicated circumstance among others accounts for prevalence of condensation electric power plants in the scheme of electrogenerating capacities that provide work for the light industry enterprises. And this leads to irregularity of their energy supply. Transition to gas CHPs with required scheme of the energy flow generation is associated primarily with creation of inherent generating sources, which in its turn poses a number of challenges on modification of the thermal treatment schemes of technological flows. The problem is solved in package with developing energy consumption of the finishing department as well as the entire enterprise. The study shows the capability of utilizing low pressure hot water alongside with steam, which paves the way to the recuperative

Intentional back flow effects on ruptured steam generator cooldown during a SGTR event for KSNP

International Nuclear Information System (INIS)

Seok, Jeong Park; Cheol, Woo Kim; Chul, Jin Choi; Jong, Tae Seo

2001-01-01

For an optimum recovery from a Steam Generator Tube Rupture (SGTR) event, the operators are directed to isolate the steam generator (SG) with ruptured tube(s) as early as possible in order to minimize the radioactive material release. However, the Reactor Coolant System (RCS) cooldown and depressurization to the Residual Heat Removal (RHR) System operation conditions using the intact SG only can not be readily achievable unless the affected SG is properly cooled since the isolated SG remains at high temperature even though the RCS has been cooled down. Therefore, a study on the intentional back flow from the ruptured SG secondary side to the RCS was performed to evaluate its effectiveness on the ruptured SG cooldown during a SGTR event for the pressurized light water reactor, especially for the Korean Standard Nuclear Power Plant (KSNP). In order to evaluate the intentional back flow effect, a series of analyses was conducted by using RELAP5/MOD3 computer code. In these analyses, the primary and secondary systems of KSNP are modeled including the major Nuclear Steam Supply System (NSSS) components such as the reactor vessel, steam generators, hot and cold legs, pressurizer, and reactor coolant pumps. Also, the key safety systems and control systems are modeled. Using this model, two possible methods of the ruptured SG cooldown by using back flow after RCS cooldown were evaluated: the first method is a tube uncover method, and the second method is a SG drain (back flow) and fill method. (author)

Steam generator asset management: integrating technology and asset management

International Nuclear Information System (INIS)

Shoemaker, P.; Cislo, D.

2006-01-01

, and nuclear fuel, are the most costly components within a nuclear steam supply system, yet they don't lend themselves well to asset management practices. However, application of asset management principles to these components represents the largest potential return for asset management within nuclear generation and sustaining continued plant operation, to include life extensions. Recognizing this critical gap, AREVA launched a Steam Generator Secondary Side Vision to develop advanced technologies for the management of nuclear steam generators. These technologies include advanced mitigation techniques, to include non-invasive techniques, new inspection techniques, predictive modeling and expert systems aimed at minimizing and managing steam generator corrosion and risks. (author)

Steam purity in PWRs

International Nuclear Information System (INIS)

Hopkinson, J.; Passell, T.

1982-01-01

Reports that 2 EPRI studies of PWRs prove that impure steam triggers decay of turbine metals. Reveals that EPRI is attempting to improve steam monitoring and analysis, which are key steps on the way to deciding the most cost-effective degree of steam purity, and to upgrade demineralizing systems, which can then reliably maintain that degree of purity. Points out that 90% of all cracks in turbine disks have occurred at the dry-to-wet transition zone, dubbed the Wilson line. Explains that because even very clean water contains traces of chemical impurities with concentrations in the parts-per-billion range, Crystal River-3's secondary loop was designed with even more purification capability; a deaerator to remove oxygen and prevent oxidation of system metals, and full-flow resin beds to demineralize 100% of the secondary-loop water from the condenser. Concludes that focusing attention on steam and water chemistry can ward off cracking and sludge problems caused by corrosion

Steam System Balancing and Tuning for Multifamily Residential Buildings in Chicagoland - Second Year of Data Collection

Energy Technology Data Exchange (ETDEWEB)

Choi, J.; Ludwig, P.; Brand, L.

2013-08-01

Steam heated buildings often suffer from uneven heating as a result of poor control of the amount of steam entering each radiator. In order to satisfy the heating load to the coldest units, other units are overheated. As a result, some tenants complain of being too hot and open their windows in the middle of winter, while others complain of being too cold and are compelled to use supplemental heat sources. Building on previous research, CNT Energy identified 10 test buildings in Chicago and conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam system balancing. A package of common steam balancing measures was assembled and data were collected on the buildings before and after these retrofits were installed to investigate the process, challenges, and the cost effectiveness of improving steam systems through improved venting and control systems. The test buildings that received venting upgrades and new control systems showed 10.2% savings on their natural gas heating load, with a simple payback of 5.1 years. The methodologies for and findings from this study are presented in detail in this report. This report has been updated from a version published in August 2012 to include natural gas usage information from the 2012 heating season and updated natural gas savings calculations.

Investigation of a combined gas-steam system with flue gas recirculation

Directory of Open Access Journals (Sweden)

Chmielniak Tadeusz

2016-06-01

Full Text Available This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.

Fabrication of remote steam atomized scrubbers for DWPF off-gas system

International Nuclear Information System (INIS)

Nielsen, M.G.; Lafferty, J.D.

1988-01-01

The defense waste processing facility (DWPF) is being constructed for the purpose of processing high-level waste from sludge to a vitrified borosilicate glass. In the operation of continuous slurry-fed melters, off-gas aerosols are created by entrainment of feed slurries and the vaporization of volatile species from the molten glass mixture. It is necessary to decontaminate these aerosols in order to minimize discharge of airborne radionuclide particulates. A steam atomized scrubber (SAS) has been developed for DWPF which utilizes a patented hydro- sonic system gas scrubbing method. The Hydro-Sonic System utilizes a steam aspirating-type venturi scrubber that requires very precise fabrication tolerances in order to obtain acceptable decontamination factors. In addition to the process-related tolerances, precision mounting and nozzle tolerances are required for remote service at DWPF

Water and steam sampling systems; Provtagningssystem foer vatten och aanga

Energy Technology Data Exchange (ETDEWEB)

Hellman, Mats

2009-10-15

The supervision of cycle chemistry can be divided into two parts, the sampling system and the chemical analysis. In modern steam generating plants most of the chemical analyses are carried out on-line. The detection limits of these analyzers are pushed downward to the ppt-range (parts per trillion), however the analyses are not more correct than the accuracy of the sampling system. A lot of attention has been put to the analyzers and the statistics to interpret the results but the sampling procedures has gained much less attention. This report aims to give guidance of the considerations to be made regarding sampling systems. Sampling is necessary since most analysis of interesting parameters cannot be carried out in- situ on-line in the steam cycle. Today's on-line instruments for pH, conductivity, silica etc. are designed to meet a water sample at a temperature of 10-30 deg C. This means that the sampling system has to extract a representative sample from the process, transport and cool it down to room temperature without changing the characteristics of the fluid. In the literature research work, standards and other reports can be found. Although giving similar recommendations in most aspects there are some discrepancies that may be confusing. This report covers all parts in the sampling system: Sample points and nozzles; Sample lines; Valves, regulating and on-off; Sample coolers; Temperature, pressure and flow rate control; Cooling water; and Water recovery. On-line analyzers connecting to the sampling system are not covered. This report aims to clarify what guidelines are most appropriate amongst the existing ones. The report should also give guidance to the design of the sampling system in order to achieve representative samples. In addition to this the report gives an overview of the fluid mechanics involved in sampling. The target group of this report is owners and operators of steam generators, vendors of power plant equipment, consultants working in

Alteration of biomacromolecule in corn by steam flaking in relation to biodegradation kinetics in ruminant, revealed with vibrational molecular spectroscopy

Science.gov (United States)

Xu, Ningning; Liu, Jianxin; Yu, Peiqiang

2018-02-01

Large scale of steam flaked corn has been used in dairy ration to maintain high milk production level. This study aimed to determine effects of steam flaking on processing-induced intrinsic molecular structure changes that were associated with rumen degradation kinetics and nutrients supply. The advanced vibrational molecular spectroscopy was applied to reveal the processing-induced intrinsic structure changes on a molecular basis. The rumen degradation kinetics and nutrient supply were determined using in situ approach in ruminant livestock system. Raw corn grain (RC) and steam flaked corn grain (SFC) were obtained from two different processing plants. The results showed that (1) Compared to RC, SFC had greater truly digestible non-fiber carbohydrate [tdNFC: 86.8 versus 78.0% dry matter (DM)], but lower truly digestible crude protein [tdCP: 7.7 versus 9.0% DM]. (2) The steam flaking increased (P < 0.01) rumen degradable DM (RDDM) and starch (RDSt), but decreased (P < 0.01) rumen degradable protein (RDP). (3) Molecular absorbance intensities of most carbohydrate biopolymers were greater in SFC (P < 0.01), but protein amides associated molecular spectral intensities were lower (P < 0.01) in SFC. (4). The molecular structure and nutrient interactive study showed that carbohydrate spectral intensities were positively (P < 0.10) associated with RDDM and RDSt and protein amide spectral intensities were positively (P < 0.10) associated with RDP. This results indicated that the steam flaking induced molecular structure changes had an interactive relationship with rumen degradation kinetics.

1000 MW steam turbine for nuclear power station

International Nuclear Information System (INIS)

Drahy, J.

1987-01-01

Skoda Works started the manufacture of the 1000 MW steam turbine for the Temelin nuclear power plant. The turbine will use saturated steam at 3,000 r.p.m. It will allow steam supply to heat water for district heating, this of an output of 893 MW for a three-stage water heating at a temperature of 150/60 degC or of 570 MW for a two-stage heating at a temperature of 120/60 degC. The turbine features one high-pressure and three identical low-pressure stages. The pressure gradient between the high-pressure and the low-pressure parts was optimized as concerns the thermal efficiency of the cycle and the thermodynamic efficiency of the low-pressure part. A value of 0.79 MPa was selected corresponding to the maximum flow rate of the steam entering the turbine. This is 5,495 t/h, the admission steam parameters are 273.3 degC and 5.8 MPa. The feed water temperature is 220.9 degC. It is expected that throughout the life of the turbine, there will be 300 cold starts, 1,000 starts following shutdown for 55 to 88 hours, and 600 starts following shutdown for 8 hours. (Z.M.). 8 figs., 1 ref

Multifrequency eddy-current system for inspection of steam generator turbine

International Nuclear Information System (INIS)

Davis, T.J.

1980-11-01

The objectives of this program were to: determine the maximum advantage of the multifrequency eddy current method for nuclear steam generator tubing inspection; simplify system operating procedures and enhance presentation of mutifrequency data; and evaluate multifrequency methods for inspecting recently encountered types of anomalies such as circumferential cracks, inside diameter flaws, and flaws in dented regions. New test methods developed under the program have resulted in a dramatic improvement over earlier multifrequency work. The methods rely on judicious selection of test frequencies and the simultaneous use of differential and absolute multiparameter inspection. Flaws may be sized and profiled with increased accuracy over that of the single-frequency method, and improved rejection of indications from unwanted parameters such as support plates and probe wobble has been obtained. The ability to detect and size support cracks in both corroded and non-corroded supports has been demonstrated on a laboratory basis. A field-usable test system employing four test frequencies was developed under the program and has been evaluated in the EPRI steam generator mockup. Some of the new technology used in this system has been commercialized into the new Zetec MIZ-12 multifrequency system

Assessing the thermal-hydraulic behaviour of steam generators in a CANDU-6 type NPP in the event of MSSV blockage on the open-setting

International Nuclear Information System (INIS)

Dinca, Elena

2004-01-01

This work aims at achieving an analysis regarding the thermal-hydraulic behaviour of a CANDU-6 type NPP in the event of the blockage on open-setting of an MSSV (Main Steam Safety Valve) for steam relief from steam generators. The systems studied are main steam and feedwater mixture in the secondary circuit, particularly being analyzed the behaviour of the steam generators as well as the primary heat transfer and the control system of heavy water pressure and inventory in the primary system. One supposes that the MSSV blockage occurs directly after its opening in the event of an accident that led to the a steam pressure rise in the steam generators up to the threshold value of MSSV o penning. The analysis was applied to two events of initiation which lead to MSSV o penning, namely a Class IV loss of electric supply and loss of vacuum in turbine condenser. In the simulation of the events selected for analysis a long elapse of time is supposed (3600 seconds) and no operator intervention while the NPP is operating at rating power and equilibrium fuel regime. Each of the two events were analyzed for two distinct sets of conditions of event initiation and evolution. The study was focussed on the behaviour of NPP, particularly of the steam generators, and on the estimation of the amount of water in the secondary circuit released into the atmosphere during the event. The analysis is of deterministic type and supplies information required by the Probabilistic Safety Assessment (PSA) applied to nuclear facilities in establishing the operation procedures and documentation. The analysis was based on design data for a CANDU-6 NPP and the HYDN3 code for thermal-hydraulic computation in CANDU type NPPs. In the paper there are presented the analysis, methodology, models, hypotheses and the input data as well as the analyzed cases. Within the computing code some models were developed to allow simulating the event sequences chosen for analyses. The results are plotted and

Maintaining steam/condensate lines

International Nuclear Information System (INIS)

Russum, S.A.

1992-01-01

Steam and condensate systems must be maintained with the same diligence as the boiler itself. Unfortunately, they often are not. The water treatment program, critical to keeping the boiler at peak efficiency and optimizing operating life, should not stop with the boiler. The program must encompass the steam and condensate system as well. A properly maintained condensate system maximizes condensate recovery, which is a cost-free energy source. The fuel needed to turn the boiler feedwater into steam has already been provided. Returning the condensate allows a significant portion of that fuel cost to be recouped. Condensate has a high heat content. Condensate is a readily available, economical feedwater source. Properly treated, it is very pure. Condensate improves feedwater quality and reduces makeup water demand and pretreatment costs. Higher quality feedwater means more reliable boiler operation

Numerical Analysis on Transient of Steam-gas Pressurizer

International Nuclear Information System (INIS)

Kim, Jong-Won; Lee, Yeon-Gun; Park, Goon-Cherl

2008-01-01

In nuclear reactors, various pressurizers are adopted to satisfy their characteristics and uses. The additional active systems such as heater, pressurizer cooler, spray and insulator are essential for a steam or a gas pressurizer. With a steam-gas pressurizer, additional systems are not required due to the use of steam and non-condensable gas as pressure-buffering materials. The steam-gas pressurizer in integrated small reactors experiences very complicated thermal-hydraulic phenomena. To ensure the integrity of this pressurizer type, the analysis on the transient behavior of the steam-gas pressure is indispensable. For this purpose, the steam-gas pressurizer model is introduced to predict the accurate system pressure. The proposed model includes bulk flashing, rainout, inter-region heat and mass transfer and wall condensation with non-condensable gas. However, the ideal gas law is not applied because of significant interaction at high pressure between steam and non-condensable gas. The results obtained from this proposed model agree with those from pressurizer tests. (authors)

The development of control systems for high power steam turbines

International Nuclear Information System (INIS)

Mathey, M.

1983-01-01

The functional and technological aspects of developments in the field of control systems for steam turbines over the last twenty years are analyzed. These developments have now culminated in very sophisticated systems which closely link electronics to high pressure hydraulic technology. A detailed description of these systeme high-lighting the high technical level of the control methods and the flexibility and reliability in service of turbines controlled in this way is given [fr

Containment heat removal system

International Nuclear Information System (INIS)

Wade, G.E.; Barbanti, G.; Gou, P.F.; Rao, A.S.; Hsu, L.C.

1992-01-01

This patent describes a nuclear system of a type including a containment having a nuclear reactor therein, the nuclear reactor including a pressure vessel and a core in the pressure vessel, the system. It comprises a gravity pool of coolant disposed at an elevation sufficient to permit a flow of coolant into the nuclear reactor pressure vessel against a predetermined pressure within the nuclear reactor pressure vessel; means for reducing a pressure of steam in the nuclear reactor pressure vessel to a value less than the predetermined pressure in the event of a nuclear accident, the means including a depressurization valve connected to the pressure vessel, the means further including steam heat dissipating means such dissipating means including a suppression pool; a supply of water in the suppression pool, there being a headspace in the suppression pool above the water supply; a substantial amount of air in the head space; means for feeding pressurized steam from the nuclear reactor pressure vessel to a location under a surface of the supply of water, the supply of water being effective to absorb heat sufficient to reduce steam pressure below the predetermined pressure; and a check valve for communicating the headspace with the containment, the check valve being oriented to vent air in the headspace to the containment when a pressure in the headspace exceeds a pressure in the containment by a predetermined pressure differential

Control system for a nuclear power producing unit

International Nuclear Information System (INIS)

Durrant, O.W.

1978-01-01

The invention provides in a control system for a nuclear power producing unit comprising a pressurized water reactor, a once-through steam generator provided with feedwater supply means, a turbine-generator supplied with steam from the steam generator and means maintaining a flow of pressurized water through the reactor and steam generator. The combination comprising; means generating a feed forward control signal proportional to the desired power output of the power producing unit, a second means for adjusting the reactor heat release, a third means for adjusting the rate of flow of feedwater to the steam generator, the second and third means solely responsive to and operated in parallel from the feed forward control signal whereby the reactor heat release and the rate of flow of feedwater to the steam generator are each maintained in a discrete functional relationship to the feed forward control signal

Technical evaluation: 300 Area steam line valve accident

International Nuclear Information System (INIS)

1993-08-01

On June 7, 1993, a journeyman power operator (JPO) was severely burned and later died as a result of the failure of a 6-in. valve that occurred when he attempted to open main steam supply (MSS) valve MSS-25 in the U-3 valve pit. The pit is located northwest of Building 331 in the 300 Area of the Hanford Site. Figure 1-1 shows a layout of the 300 Area steam piping system including the U-3 steam valve pit. Figure 1-2 shows a cutaway view of the approximately 10- by 13- by 16-ft-high valve pit with its various steam valves and connecting piping. Valve MSS-25, an 8-in. valve, is located at the bottom of the pit. The failed 6-in. valve was located at the top of the pit where it branched from the upper portion of the 8-in. line at the 8- by 8- by 6-in. tee and was then ''blanked off'' with a blind flange. The purpose of this technical evaluation was to determine the cause of the accident that led to the failure of the 6-in. valve. The probable cause for the 6-in. valve failure was determined by visual, nondestructive, and destructive examination of the failed valve and by metallurgical analysis of the fractured region of the valve. The cause of the accident was ultimately identified by correlating the observed failure mode to the most probable physical phenomenon. Thermal-hydraulic analyses, component stress analyses, and tests were performed to verify that the probable physical phenomenon could be reasonably expected to produce the failure in the valve that was observed

46 CFR 61.15-5 - Steam piping.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main boiler...

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. (TECOGEN, Inc., Waltham, MA (United States))

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Steam atmosphere drying concepts using steam exhaust recompression

Energy Technology Data Exchange (ETDEWEB)

DiBella, F.A. [TECOGEN, Inc., Waltham, MA (United States)

1992-08-01

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg{sub evap} to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

Risk-based inspection and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, Kazunari; Nagai, Satoshi; Akikuni, Yasunari; Fujiwara, Toshihiro; Furuya, Kenichiro; Matsumoto, Shigeru; Takagi, Kentaro; Kawabata, Taro

2004-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants

Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report

Energy Technology Data Exchange (ETDEWEB)

2002-10-01

This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

Steam system opportunity assessment for the pulp and paper, chemical manufacturing, and petroleum refining industries: Main report

Energy Technology Data Exchange (ETDEWEB)

None, None

2002-10-01

This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

Leak detection of steam or water into sodium in steam generators of liquid-metal fast breeder reactors

International Nuclear Information System (INIS)

Hans, R.; Dumm, K.

1977-01-01

The leakage of water or steam into sodium in LMFBR steam generators, including a study of how leaks are detected and located as well as the potential damage that could be caused by such leaks, is surveyed. The most interesting steam generator designs evolving in those countries that develop and construct LMFBRs are presented. The relevant protection measures are described. Fault conditions are defined and descriptions given of possible sequences of events leading to abnormal conditions in a steam generator. Taking into account theory, the potential of the hydrogen and oxygen detection systems is discussed. Different hydrogen and oxygen detection systems are fully described. In so far as interesting technical solutions are concerned, previously developed devices have also been taken into account. The way oxygen detection supplements hydrogen detection is described by listing the available oxygen measuring devices and the relevant theory. Only a few sonic and accelerometer measurements have been made on complete steam generator units so there is little system data available. Descriptions, however, have been included to give the state of the art achieved for the sensors and the achieved sensitivities or band widths. The potential of this monitoring method is made evident by adding the technical data of the sensors. Furthermore, the available systems for monitoring medium and large leakages are described. Finally, recommendations are made concerning steam generator development and the application of hydrogen and oxygen detection systems, as well as acoustic measuring methods for small-leakage detection

TEXT poloidal coil systems power supplies

International Nuclear Information System (INIS)

Hutchins, S.H.; Brower, D.F.

1977-01-01

TEXT is a convertional iron core tokamak which will have a toroidal field of 3.0 Tesla produced by room temperature copper coils and a maximum plasma current pulse of 400 kA induced by a 40 turn Ohmic Heating coil. The major radius is 100 cm and the minor radius of the plasma is 28 cm. The machine is intended for basic research in tokamak plasma physics and atomic physics and is designed primarily to provide a stable hot plasma, extremely good diagnostic access, and reliable operation. The discharge pulse length will be 300 msec and the repetition period 120 seconds. Power for the toroidal field coils and for the ohmic heating supply is provided by a 100 MVA energy storage alternator. The vertical field, horizontal field, fast positioning, and discharge cleaning power supply systems are powered from the Tokamak Laboratory power mains. The ohmic heating power system consists of an SCR controlled premagnetizing supply and commutation circuit, the main ohmic heating capacitor bank to provide plasma breakdown and current rise, and an SCR controlled power supply which sustains plasma current during the 300 ms pulse. The vertical field power system uses a small capacitor bank and an SCR controlled supply. The horizontal field has a reversible SCR controlled supply, and the fast positioning coils are powered by bipolar output transistor controlled supplies. This paper describes the loads, required wave forms, and the specifications for these power supply systems

Steam Distillation with Induction Heating System: Analysis of Kaffir Lime Oil Compound and Production Yield at Various Temperatures

International Nuclear Information System (INIS)

Zuraida Muhammad; Zakiah Mohd Yusoff; Mohd Noor Nasriq Nordin

2013-01-01

The steam temperature during the extraction process has a great influence on the essential oil quality. .This study was conducted to analyze the compound of kaffir-lime oil during extracting at different steam temperature using GC-MS analysis. The extraction was carried out by using steam distillation based on induction heating system at different extraction temperature such as 90, 95 and 100 degree Celsius, the power of the induction heating system is fixed at 1.6 kW. Increment of the steam temperature will increase the oil yield. In terms of oil composition, extraction at lower temperature resulted high concentration for four marker compounds of kaffir-lime oil which are α-pinene, sabinene, limonene, β-pinene. (author)

Steam relief valve control system for a nuclear reactor

International Nuclear Information System (INIS)

Torres, J.M.

1976-01-01

Described is a turbine follow system and method for Pressurized Water Reactors utilizing load bypass and/or atmospheric dump valves to provide a substitute load upon load rejection by bypassing excess steam to a condenser and/or to the atmosphere. The system generates a variable pressure setpoint as a function of load and applies an error signal to modulate the load bypass valves. The same signal which operates the bypass valves actuates a control rod automatic withdrawal prevent to insure against reactor overpower

Use of mock-up training to reduce personnel exposure at the North Anna Unit 1 Steam Generator Replacement Project

Energy Technology Data Exchange (ETDEWEB)

Henry, H.G. [Virginia Power, Mineral, VA (United States); Reilly, B.P. [Bechtel Power Corp., Gaithersburg, MD (United States)

1995-03-01

The North Anna Power Station is located on the southern shore of Lake Anna in Louisa County, approximately forty miles northwest of Richmond, Virginia. The two 910 Mw nuclear units located on this site are owned by Virginia Electric and Power Company (Virginia Power) and Old Dominion Electric Cooperative and operated by Virginia Power. Fuel was loaded into Unit 1 in December 1977, and it began commercial operation in June 1978. Fuel was loaded into Unit 2 in April 1980 and began commercial operation in December 1980. Each nuclear unit includes a three-coolant-loop pressurized light water reactor nuclear steam supply system that was furnished by Westinghouse Electric Corporation. Included within each system were three Westinghouse Model 51 steam generators with alloy 600, mill-annealed tubing material. Over the years of operation of Unit 1, various corrosion-related phenomena had occurred that affected the steam generators tubing and degraded their ability to fulfill their heat transfer function. Advanced inspection and repair techniques helped extend the useful life of the steam generators, but projections based on the results of the inspections indicated that the existing steam generators tubing and degraded their ability to fullfill their heat transfer function. Advanced inspection and repair techniques helped extend the useful life of the steam generators, but projections based on the results of the inspections indicated that the existing steam generators would not last their design life and must be repaired. To this end Virginia Power determined that a steam generator replacement (SGR) program was necessary to remove the old steam generator tube bundles and lower shell sections, including the channel heads (collectively called the lower assemblies), and replace them with new lower assemblies incorporating design features that will prevent the degradation problems that the old steam generators had experienced.

Power supply system for KSTAR neutral beam injector

Energy Technology Data Exchange (ETDEWEB)

Cho, W., E-mail: franciscocho@nfri.re.kr; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.

2015-10-15

Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to

Power supply system for KSTAR neutral beam injector

International Nuclear Information System (INIS)

Cho, W.; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.

2015-01-01

Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to

Simulation and analysis of main steam control system based on heat transfer calculation

Science.gov (United States)

Huang, Zhenqun; Li, Ruyan; Feng, Zhongbao; Wang, Songhan; Li, Wenbo; Cheng, Jiwei; Jin, Yingai

2018-05-01

In this paper, after thermal power plant 300MW boiler was studied, mat lab was used to write calculation program about heat transfer process between the main steam and boiler flue gas and amount of water was calculated to ensure the main steam temperature keeping in target temperature. Then heat transfer calculation program was introduced into Simulink simulation platform based on control system multiple models switching and heat transfer calculation. The results show that multiple models switching control system based on heat transfer calculation not only overcome the large inertia of main stream temperature, a large hysteresis characteristic of main stream temperature, but also adapted to the boiler load changing.

Urban Wood-Based Bio-Energy Systems in Seattle

Energy Technology Data Exchange (ETDEWEB)

Stan Gent, Seattle Steam Company

2010-10-25

Seattle Steam Company provides thermal energy service (steam) to the majority of buildings and facilities in downtown Seattle, including major hospitals (Swedish and Virginia Mason) and The Northwest (Level I) Regional Trauma Center. Seattle Steam has been heating downtown businesses for 117 years, with an average length of service to its customers of 40 years. In 2008 and 2009 Seattle Steam developed a biomass-fueled renewable energy (bio-energy) system to replace one of its gas-fired boilers that will reduce greenhouse gases, pollutants and the amount of waste sent to landfills. This work in this sub-project included several distinct tasks associated with the biomass project development as follows: a. Engineering and Architecture: Engineering focused on development of system control strategies, development of manuals for start up and commissioning. b. Training: The project developer will train its current operating staff to operate equipment and facilities. c. Flue Gas Clean-Up Equipment Concept Design: The concept development of acid gas emissions control system strategies associated with the supply wood to the project. d. Fuel Supply Management Plan: Development of plans and specifications for the supply of wood. It will include potential fuel sampling analysis and development of contracts for delivery and management of fuel suppliers and handlers. e. Integrated Fuel Management System Development: Seattle Steam requires a biomass Fuel Management System to track and manage the delivery, testing, processing and invoicing of delivered fuel. This application will be web-based and accessed from a password-protected URL, restricting data access and privileges by user-level.

Passive safe small reactor for distributed energy supply system sited in water filled pit at seaside

International Nuclear Information System (INIS)

Ishida, Toshihisa; Imayoshi, Shou

2003-01-01

Japan Atomic Energy Research Institute has developed a Passive Safe Small Reactor for Distributed Energy Supply System (PSRD) concept. The PSRD is an integrated-type PWR with reactor thermal power of 100 to 300 MW aimed at supplying electricity, district heating, etc. In design of the PSRD, high priority is laid on enhancement of safety as well as improvement of economy. Safety is enhanced by the following means: i) Extreme reduction of pipes penetrating the reactor vessel, by limiting to only those of the steam, the feed water and the safety valves, ii) Adoption of the water filled containment and the passive safety systems with fluid driven by natural circulation force, and iii) Adoption of the in-vessel type control rod drive mechanism, accompanying a passive reactor shut-down device. For improvement of economy, simplification of the reactor system and long operation of the core over five years without refueling with low enriched UO 2 fuel rods are achieved. To avoid releasing the radioactive materials to the circumstance even if a hypothetical accident, the containment is submerged in a pit filled with seawater at a seaside. Refueling or maintenance of the reactor can be conducted using an exclusive barge instead of the reactor building. (author)

System for combustion of sunflower shells in industrial steam generators

International Nuclear Information System (INIS)

Todoriev, Kh.

2000-01-01

The paper presents an economically efficient solution for reconstruction of steam generators with steam production over 5 t/h using foregoing cyclone chamber for sunflower shells combustion. For average fuel caloricity 9 445 ccal/kg and sunflower shells caloricity between 3 485 and 3 750 ccal/kg, the petroleum saving is 68.78% for an average boiler efficiency 4.6 t/h steam

Assessment of System Behavior and Actions Under Loss of Electric Power For CANDU

Energy Technology Data Exchange (ETDEWEB)

Kang, San Ha; Moon, Bok Ja; Kim, Seoung Rae [Nuclear Engineering Service and Solution Co., Ltd., Daejeon (Korea, Republic of)

2014-05-15

For the analysis, the CANDU-6 plant in Korea is considered and only the passive components are operable. The other systems are assumed to be at failed condition due to the loss of electric power. At this accident, only the inventories remained in the primary heat transport system (PHTS) and steam generator can be used for the decay heat removal. Due to the transfer of decay heat, the inventory of steam generator secondary side is discharged to the air through passive operation of main steam safety valves (MSSVs). After the steam generators are dried, the PHTS is over-pressurized and the coolant is discharged to fuelling machine vault through passive operation of degasser condenser tank relief valves (DCRVs). Under this situation, the maintenance of the integrity of PHTS is important for the protection of radionuclides release to the environment. Thus, deterministic analysis using CATHENA code is carried out for the simulation of the accident and the appropriate operator action is considered. The loss of electric power results in the depletion of steam generator inventory which is necessary for the decay heat removal. If only the passive system is credited, the PT can be failed after the steam generator is depleted. For the prevention of the PT failure, the feedwater should be supplied to the steam generator before 4,800s after the accident. The feedwater can be supplied using water in dousing tank if the steam generators are depressurized. The decay heat from the core is removed through natural circulation if the feedwater can be supplied continuously.

Target study of heat supply from Northern Moravia nuclear power plant

International Nuclear Information System (INIS)

Pospisil, V.

The construction is envisaged in Northern Moravia of a nuclear power plant near Blahutovice in the Novy Jicin district. Heat produced by the nuclear power plant will only be used for district heating; process heat will be supplied from local steam sources. An example is discussed of the Prerov locality which currently is supplied from the Prerov heating and power plant (230 MW), a heating plant (36 MW) and from local sources (15 NW). The study estimates that a thermal power of 430 MW will be required at a time of the start of heat supplies from the nuclear power plant. All heat supply pipelines will be designed as a two-tube system divided into sections with section pipe fittings. The number and location of pipe fittings will be selected depending on the terrain configuration. Water of the maximum outlet temperature of 150 degC will be used as a coolant. The control of the system for Northern Moravia is briefly described. (J.P.)

Coupling of high temperature nuclear reactor with chemical plant by means of steam loop with heat pump

Directory of Open Access Journals (Sweden)

Kopeć Mariusz

2017-01-01

Full Text Available High temperature nuclear reactors (HTR can be used as an excellent, emission-free source of technological heat for various industrial applications. Their outlet helium temperature (700°-900°C allows not only for heat supply to all processes below 600°C (referred to as “steam class”, but also enables development of clean nuclear-assisted hydrogen production or coal liquefaction technologies with required temperatures up to 900°C (referred to as “chemical class”. This paper presents the results of analyses done for various configurations of the steam transport loop coupled with the high-temperature heat pump designed for “chemical class” applications. The advantages and disadvantages as well as the key issues are discussed in comparison with alternative solutions, trying to answer the question whether the system with the steam loop and the hightemperature heat pump is viable and economically justified.

CAREM-25 Steam Generator Stability Analysis

International Nuclear Information System (INIS)

Rabiti, A.; Delmastro, D.

2003-01-01

In this work the stability of a once-through CAREM-25 steam generator is analyzed.A fix nodes numerical model, that allows the modelling of the liquid, two-phase and superheated steam zones, is implemented.This model was checked against a mobile finite elements model under saturated steam conditions at the channel exit and a good agreement was obtained.Finally the stability of a CAREM steam generator is studied and the range of in let restrictions that a assure the system stability is analyzed

Conceptual design of small-sized HTGR system (1). Major specifications and system designs

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Tazawa, Yujiro; Yan, Xing L.; Tachibana, Yukio

2011-06-01

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a 50MWt small-sized high temperature gas cooled reactor (HTGR) for steam supply and electricity generation (HTR50S), which is a first-of-kind of the commercial plant or a demonstration plant of a small-sized HTGR system for steam supply to the industries and district heating and electricity generation by a steam turbine, to deploy in developing countries in the 2030s. The design philosophy is that the HTR50S is a high advanced reactor, which is reducing the R and D risk based on the HTTR design, upgrading the performance and reducing the cost for commercialization by utilizing the knowledge obtained by the HTTR operation and the GTHTR300 design. The major specifications of the HTR50S were determined and targets of the technology demonstration using the HTR50S (e.g., the increasing the power density, reduction of the number of uranium enrichment in the fuel, increasing the burn up, side-by-side arrangement between the reactor pressure vessel and the steam generator) were identified. In addition, the system design of HTR50S, which offers the capability of electricity generation, cogeneration of electricity and steam for a district heating and industries, was performed. Furthermore, a market size of small-sized HTGR systems was investigated. (author)

Commercially Available Activated Carbon Fiber Felt Enables Efficient Solar Steam Generation.

Science.gov (United States)

Li, Haoran; He, Yurong; Hu, Yanwei; Wang, Xinzhi

2018-03-21

Sun-driven steam generation is now possible and has the potential to help meet future energy needs. Current technologies often use solar condensers to increase solar irradiance. More recently, a technology for solar steam generation that uses heated surface water and low optical concentration is reported. In this work, a commercially available activated carbon fiber felt is used to generate steam efficiently under one sun illumination. The evaporation rate and solar conversion efficiency reach 1.22 kg m -2 h -1 and 79.4%, respectively. The local temperature of the evaporator with a floating activated carbon fiber felt reaches 48 °C. Apart from the high absorptivity (about 94%) of the material, the evaporation performance is enhanced thanks to the well-developed pores for improved water supply and steam escape and the low thermal conductivity, which enables reduced bulk water temperature increase. This study helps to find a promising material for solar steam generation using a water evaporator that can be produced economically (∼6 $/m 2 ) with long-term stability.

Dynamic modelling of nuclear steam generators

International Nuclear Information System (INIS)

Kerlin, T.W.; Katz, E.M.; Freels, J.; Thakkar, J.

1980-01-01

Moving boundary, nodal models with dynamic energy balances, dynamic mass balances, quasi-static momentum balances, and an equivalent single channel approach have been developed for steam generators used in nuclear power plants. The model for the U-tube recirculation type steam generator is described and comparisons are made of responses from models of different complexity; non-linear versus linear, high-order versus low order, detailed modeling of the control system versus a simple control assumption. The results of dynamic tests on nuclear power systems show that when this steam generator model is included in a system simulation there is good agreement with actual plant performance. (author)

Primary separator replacement for Bruce Unit 8 steam generators

International Nuclear Information System (INIS)

Roy, S.B.; Mewdell, C.G.; Schneider, W.G.

2000-01-01

During a scheduled maintenance outage of Bruce Unit 8 in 1998, it was discovered that the majority of the original primary steam separators were damaged in two steam generators. The Bruce B steam generators are equipped with GXP type primary cyclone separators of B and W supply. There were localized perforations in the upper part of the separators and large areas of generalized wall thinning. The degradation was indicative of a flow related erosion corrosion mechanism. Although the unit- restart was justified, it was obvious that corrective actions would be necessary because of the number of separators affected and the extent of the degradation. Repair was not considered to be a practical option and it was decided to replace the separators, as required, in Unit 8 steam generators during an advanced scheduled outage. GXP separators were selected for replacement to minimize the impact on steam generator operating characteristics and analysis. The material of construction was upgraded from the original carbon steel to stainless steel to maximize the assurance of full life. The replacement of the separators was a first of a kind operation not only for Ontario Power Generation and B and W but also for all CANDU plants. The paper describes the degradations observed and the assessments, the operating experience, manufacture and installation of the replacement separators. During routine inspection in 1998, many of the primary steam separators in two of steam generators at Bruce Nuclear Division B Unit 8 were observed to have through wall perforations. This paper describes assessment of this condition. It also discusses the manufacture and testing of replacement primary steam separators and the development and execution of the replacement separator installation program. (author)

Manpower development for safe operation of nuclear power plant. China. Main steam bypass system operation and maintenance. Task: 6.1.6. Technical report

International Nuclear Information System (INIS)

Stubley, P.H.

1994-01-01

This mission concentrated on the Steam Bypass system of Qinshan Nuclear Power Plant. The system had experienced spurious opening of the bypass valves, disrupting the steam pressure control and the steam generator level control system. A series of commissioning type tests were defined which should allow the operators to revise the setpoints used in the control of the bypass system, and thus prevent spurious opening while maintaining the desired steam pressure control during power maneuvering. Training also included giving experience from other operating plants on aspects of steam and feedwater systems and components, especially as this experience affected maintenance or gave rise to problems. Steam generated maintenance experience is especially applicable, and a future mission is planned for an expert in this field. In addition other aspects of the Chinese nuclear program was assessed to guide future missions. This included assessment of operating procedures from an availability point of view

Economic impact of latent heat thermal energy storage systems within direct steam generating solar thermal power plants with parabolic troughs

International Nuclear Information System (INIS)

Seitz, M.; Johnson, M.; Hübner, S.

2017-01-01

Highlights: • Integration of a latent heat thermal energy storage system into a solar direct steam generation power cycle. • Parametric study of solar field and storage size for determination of the optimal layout. • Evaluation of storage impact on the economic performance of the solar thermal power plant. • Economic comparison of new direct steam generation plant layout with state-of-the-art oil plant layout. - Abstract: One possible way to further reduce levelized costs of electricity of concentrated solar thermal energy is to directly use water/steam as the primary heat transfer fluid within a concentrated collector field. This so-called direct steam generation offers the opportunity of higher operating temperatures and better exergy efficiency. A technical challenge of the direct steam generation technology compared to oil-driven power cycles is a competitive storage technology for heat transfer fluids with a phase change. Latent heat thermal energy storages are suitable for storing heat at a constant temperature and can be used for direct steam generation power plants. The calculation of the economic impact of an economically optimized thermal energy storage system, based on a latent heat thermal energy storage system with phase change material, is the main focus of the presented work. To reach that goal, a thermal energy storage system for a direct steam generation power plant with parabolic troughs in the solar field was thermally designed to determine the boundary conditions. This paper discusses the economic impact of the designed thermal energy storage system based on the levelized costs of electricity results, provided via a wide parametric study. A state-of-the-art power cycle with a primary and a secondary heat transfer fluid and a two-tank thermal energy storage is used as a benchmark technology for electricity generation with solar thermal energy. The benchmark and direct steam generation systems are compared to each other, based respectively

Technical study of real-time simulation system for digital I and C system of steam generator in nuclear power plant

International Nuclear Information System (INIS)

Shi Ji; Jiang Mingyu; Ma Yunqin

2004-01-01

The real-time simulation system, which forms a interactive closed circle together with the steam generator control system, has been developed using a dynamic mathematical model of steam generator in this paper. It can provide a simulation target for upgrades of digital Instrument and Control system in Nuclear Power Plant (NPP) and is applicable for further research of control schemes. With this program, the authors have studied and analyzed the response of transient parameters to some different disturbance, the calculated results are in good agreement with those calculated by NPP simulator program. This will give a theoretical analysis for upgrades of digital I and C system in nuclear power plant

The effect of cooling conditions on convective heat transfer and flow in a steam-cooled ribbed duct

International Nuclear Information System (INIS)

Shui, Linqi; Gao, Jianmin; Shi, Xiaojun; Liu, Jiazeng; Xu, Liang

2014-01-01

This work presents a numerical and experimental investigation on the heat transfer and turbulent flow of cooling steam in a rectangular duct with 90 .deg. ribs and studies the effect of cooling conditions on the heat transfer augmentation of steam. In the calculation, the variation range of Reynolds is from 10,000 to 190,000, the inlet temperature varies from 300 .deg. C to 500 .deg. C and the outlet pressure is from 0.5MPa to 6MPa. The aforementioned wide ranges of flow parameters cover the actual operating condition of coolant used in the gas turbine blades. The computations are carried with four turbulence models (the standard k-ε, the renormalized group (RNG) k-ε, the Launder-Reece-Rodi (LRR) and the Speziale-Sarkar-Gatski (SSG) turbulence models). The comparison of numerical and experimental results reveals that the SSG turbulence model is suitable for steam flow in the ribbed duct. Therefore, adopting the conjugate calculation technique, further study on the steam heat transfer and flow characteristics is performed with SSG turbulence model. The results show that the variation of cooling condition strongly impacts the forced convection heat transfer of steam in the ribbed duct. The cooling supply condition of a relative low temperature and medium pressure could bring a considerable advantage on steam thermal enhancement. In addition, comparing the heat transfer level between steam flow and air flow, the performance advantage of using steam is also influenced by the cooling supply condition. Changing Reynolds number has little effect on the performance superiority of steam cooling. Increasing pressure would strengthen the advantage, but increasing temperature gives an opposite result.

The effect of cooling conditions on convective heat transfer and flow in a steam-cooled ribbed duct

Energy Technology Data Exchange (ETDEWEB)

Shui, Linqi; Gao, Jianmin; Shi, Xiaojun; Liu, Jiazeng; Xu, Liang [Xi' an Jiaotong University, Xi' an (China)

2014-01-15

This work presents a numerical and experimental investigation on the heat transfer and turbulent flow of cooling steam in a rectangular duct with 90 .deg. ribs and studies the effect of cooling conditions on the heat transfer augmentation of steam. In the calculation, the variation range of Reynolds is from 10,000 to 190,000, the inlet temperature varies from 300 .deg. C to 500 .deg. C and the outlet pressure is from 0.5MPa to 6MPa. The aforementioned wide ranges of flow parameters cover the actual operating condition of coolant used in the gas turbine blades. The computations are carried with four turbulence models (the standard k-ε, the renormalized group (RNG) k-ε, the Launder-Reece-Rodi (LRR) and the Speziale-Sarkar-Gatski (SSG) turbulence models). The comparison of numerical and experimental results reveals that the SSG turbulence model is suitable for steam flow in the ribbed duct. Therefore, adopting the conjugate calculation technique, further study on the steam heat transfer and flow characteristics is performed with SSG turbulence model. The results show that the variation of cooling condition strongly impacts the forced convection heat transfer of steam in the ribbed duct. The cooling supply condition of a relative low temperature and medium pressure could bring a considerable advantage on steam thermal enhancement. In addition, comparing the heat transfer level between steam flow and air flow, the performance advantage of using steam is also influenced by the cooling supply condition. Changing Reynolds number has little effect on the performance superiority of steam cooling. Increasing pressure would strengthen the advantage, but increasing temperature gives an opposite result.

Innovated feed water distributing system of VVER steam generators

International Nuclear Information System (INIS)

Matal, O.; Sousek, P.; Simo, T.; Lehota, M.; Lipka, J.; Slugen, V.

2000-01-01

Defects in feed water distributing system due to corrosion-erosion effects have been observed at many VVER 440 steam generators (SG). Therefore analysis of defects origin and consequently design development and testing of a new feed water distributing system were performed. System tests in-situ supported by calculations and comparison of measured and calculated data were focused on demonstration of long term reliable operation, definition of water flow and water chemical characteristics at the SG secondary side and their measurements and study of dynamic characteristics needed for the innovated feed water distributing system seismic features approval. The innovated feed water distributing system was installed in the SGs of two VVER units already. (author)

Development of a Nuclear Steam Supply System Thermal-Hydraulic Module for the Nuclear Power Plant Simulator Using a Best-Estimate Code, RETRAN

International Nuclear Information System (INIS)

Suh, Jae Seung

2004-08-01

The NSSS (Nuclear Steam Supply System) thermal-hydraulic programs adopted in the domestic full-scope power plant simulators were provided in early 1980s by foreign vendors. Because of limited computational capability at that time, they usually used very simplified physical models for the real-time simulation of Ness thermal-hydraulic transients, which entails inaccurate results and, thus, the possibility of so-called 'negative training', especially for complicated two-phase flows in the reactor coolant system. To resolve the problem, a realistic NSSS thermal-hydraulic program ARTS has been developed, it was based on the RETRAN code for the improvement of the Nuclear Power Plant full-scope simulator. Since ARTS is a generalized code to solve a simultaneous equation system, the smaller time-step size should be used if converged solution could not obtain even in a single volume. Therefore, dedicated models which do not force to reduce the time-step size are sometimes more suitable in terms of a real-time calculation and robustness. The PRT(Pressurizer Relief Tank) is a good example, which requires a dedicated model. The PRT consists of subcooled water in bottom and non-condensable gas in top. The sparger merged under subcooled water enhances condensation. The complicated thermal-hydraulic phenomena such as condensation, phase separation with existence of non-condensable gas makes difficult to simulate. Therefore, the PRT volume may limit the time-step size if it is modeled with a general control volume. To mitigate the time-step size reduction due to convergence failure at this component using RETRAN, the PRT model was developed as a dedicated model. The dedicated model was expected to provide reasonable results without convergence problem in the analysis of the system transients. The ARTS code guarantees the real-time calculations of almost all transients and ensures the robustness of simulations. However, there are some possibilities of calculation failure in the

Steam turbine cycle

International Nuclear Information System (INIS)

Okuzumi, Naoaki.

1994-01-01

In a steam turbine cycle, steams exhausted from the turbine are extracted, and they are connected to a steam sucking pipe of a steam injector, and a discharge pipe of the steam injector is connected to an inlet of a water turbine. High pressure discharge water is obtained from low pressure steams by utilizing a pressurizing performance of the steam injector and the water turbine is rotated by the high pressure water to generate electric power. This recover and reutilize discharged heat of the steam turbine effectively, thereby enabling to improve heat efficiency of the steam turbine cycle. (T.M.)

Steam distribution and energy delivery optimization using wireless sensors

Science.gov (United States)

Olama, Mohammed M.; Allgood, Glenn O.; Kuruganti, Teja P.; Sukumar, Sreenivas R.; Djouadi, Seddik M.; Lake, Joe E.

2011-05-01

The Extreme Measurement Communications Center at Oak Ridge National Laboratory (ORNL) explores the deployment of a wireless sensor system with a real-time measurement-based energy efficiency optimization framework in the ORNL campus. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize the energy delivery within the steam distribution system. We address the goal of achieving significant energy-saving in steam lines by monitoring and acting on leaking steam valves/traps. Our approach leverages an integrated wireless sensor and real-time monitoring capabilities. We make assessments on the real-time status of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observe the state measurements of these sensors. Our assessments are based on analysis of the wireless sensor measurements. We describe Fourier-spectrum based algorithms that interpret acoustic vibration sensor data to characterize flows and classify the steam system status. We are able to present the sensor readings, steam flow, steam trap status and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

Optimum design of a nuclear heat supply

International Nuclear Information System (INIS)

Borel, J.P.

1984-01-01

This paper presents an economic analysis for the optimum design of a nuclear heat supply to a given district-heating network. First, a general description of the system is given, which includes a nuclear power plant, a heating power plant and a district-heating network. The heating power plant is fed with steam from the nuclear power plant. It is assumed that the heating network is already in operation and that the nuclear power plant was previously designed to supply electricity. Second, a technical definition of the heat production and transportation installations is given. The optimal power of these installations is examined. The main result is a relationship between the network capacity and the level of the nuclear heat supply as a substitute for oil under the best economic conditions. The analysis also presents information for choosing the best operating mode. Finally, the heating power plant is studied in more detail from the energy, technical and economic aspects. (author)

Steam condenser

International Nuclear Information System (INIS)

Masuda, Fujio

1980-01-01

Purpose: To enable safe steam condensation by providing steam condensation blades at the end of a pipe. Constitution: When high temperature high pressure steam flows into a vent pipe having an opening under water in a pool or an exhaust pipe or the like for a main steam eacape safety valve, non-condensable gas filled beforehand in the steam exhaust pipe is compressed, and discharged into the water in the pool. The non-condensable gas thus discharged from the steam exhaust pipe is introduced into the interior of the hollow steam condensing blades, is then suitably expanded, and thereafter exhausted from a number of exhaust holes into the water in the pool. In this manner, the non-condensable gas thus discharged is not directly introduced into the water in the pool, but is suitable expanded in the space of the steam condensing blades to suppress extreme over-compression and over-expansion of the gas so as to prevent unstable pressure vibration. (Yoshihara, H.)

Exploratory Analysis of Supply Chains in the Defense Industrial Base

Science.gov (United States)

2012-04-01

hp) 2- and 4- stroke RC/modeler engines are O.S. Engine (Japan), Thunder Tiger (Taiwan), and Saito (Japan). E. Global Nature of the Supply Chain...Mexico). • The 115-HP 4- stroke Rotax 914 class engine (Austria/Germany) found in the Predator (MQ-1B) is also found in many other systems, including...Equipment 43 Pumps and Compressors 44 Furnace/Steam Plant/Drying Equipment, Nuclear Reactors 45 Plumbing, Heating , and Sanitation Equipment 49

Steam generator tube failures

International Nuclear Information System (INIS)

MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

1996-04-01

A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

Optimization of steam generators of NPP with WWER in operation with variable load

Science.gov (United States)

Parchevskii, V. M.; Shchederkina, T. E.; Gur'yanova, V. V.

2017-11-01

The report addresses the issue of the optimal water level in the horizontal steam generators of NPP with WWER. On the one hand, the level needs to be kept at the lower limit of the allowable range, as gravity separation, steam will have the least humidity and the turbine will operate with higher efficiency. On the other hand, the higher the level, the greater the supply of water in the steam generator, and therefore the higher the security level of the unit, because when accidents involving loss of cooling of the reactor core, the water in the steam generators, can be used for cooling. To quantitatively compare the damage from higher level to the benefit of improving the safety was assessed of the cost of one cubic meter of water in the steam generators, the formulated objective function of optimal levels control. This was used two-dimensional separation characteristics of steam generators. It is demonstrated that the security significantly shifts the optimal values of the levels toward the higher values, and this bias is greater the lower the load unit.

Geothermal heat-pump systems of heat supply

International Nuclear Information System (INIS)

Vasil'ev, G.P.

2004-01-01

The data on the multilayer operation of the objects, located in the climatic conditions of the central area of Russia and equipped with the geothermal heat-pumping systems of the heat supply are presented. The results of the analytical studies on evaluating the geothermal heat-pumping systems of the heat supply integration efficiency into the structure of the energy supply system, prevailing in the country, are presented [ru

A high-power millimeter wave driven steam gun for pellet injectors

International Nuclear Information System (INIS)

Itoh, Yasuyuki

1997-01-01

A concept of steam gun is proposed for using in two-stage pneumatic hydrogen isotope pellet injectors. The steam gun is driven by megawatt-level high-power millimeter waves (∼100 GHz) supplied by gyrotrons. A small amount of water is injected into its pump tube. The water is instantaneously heated by the millimeter waves and vaporized. Generated high-pressure steam accelerates a piston for compressing light gas to drive a frozen pellet. Discussions in this paper concentrate on the piston acceleration. Results show that 1 MW millimeter waves accelerate the 25 g piston to velocities of ∼200 m/s in a 1 m-long pump tube. The piston acceleration characteristics are not improved in comparison to light gas guns with first valves. The steam gun concept, however, avoids the use of a large amount of high-pressure gas for piston accelerations. In future fusion reactors, gyrotrons used during preionization and start-up phase would be available for producing required millimeter waves. (author)

Integration of torrefaction with steam power plant

Energy Technology Data Exchange (ETDEWEB)

Zakri, B.; Saari, J.; Sermyagina, E.; Vakkilainen, E.

2013-09-01

Torrefaction is one of the pretreatment technologies to enhance the fuel characteristics of biomass. The efficient and continuous operation of a torrefaction reactor, in the commercial scale, demands a secure biomass supply, in addition to adequate source of heat. Biorefinery plants or biomass-fuelled steam power plants have the potential to integrate with the torrefaction reactor to exchange heat and mass, using available infrastructure and energy sources. The technical feasibility of this integration is examined in this study. A new model for the torrefaction process is introduced and verified by the available experimental data. The torrefaction model is then integrated in different steam power plants to simulate possible mass and energy exchange between the reactor and the plants. The performance of the integrated plant is investigated for different configurations and the results are compared. (orig.)

Method for operating a steam turbine of the nuclear type with electronic reheat control of a cycle steam reheater

International Nuclear Information System (INIS)

Luongo, M.C.

1975-01-01

An electronic system is provided for operating a nuclear electric power plant with electronic steam reheating control applied to the nuclear turbine system in response to low pressure turbine temperatures, and the control is adapted to operate in a plurality of different automatic control modes to control reheating steam flow and other steam conditions. Each of the modes of control permit turbine temperature variations within predetermined constraints and according to predetermined functions of time. (Official Gazette)

Emergency systems and protection equipment of modular steam generators for fast reactors

International Nuclear Information System (INIS)

Matal, O.

The requirements are discussed for accident protection of modular steam generators for fast reactors. Accident protection is assessed for a modular through-flow steam generator and for a natural circulation modular steam generator. Benefits and constraints are shown and possible improvements are outlined for accident protection of liquid sodium fired modular steam generators. (Kr)

Development of main steam safety valve set pressure evaluating system

International Nuclear Information System (INIS)

Oketani, Koichiro; Manabe, Yoshihisa.

1991-01-01

A main steam safety valve set pressure test is conducted for all valves during every refueling outage in Japan's PWRs. Almost all operations of the test are manually conducted by a skilled worker. In order to obtain further reliability and reduce the test time, an automatic test system using a personnel computer has been developed in accordance with system concept. Quality assurance was investigated to fix system specifications. The prototype of the system was manufactured to confirm the system reliability. The results revealed that this system had high accuracy measurement and no adverse influence on the safety valve. This system was concluded to be applicable for actual use. (author)

Effect of heat transfer tube leak on dynamic characteristic of steam generator

International Nuclear Information System (INIS)

Sun Baozhi; Shi Jianxin; Li Na; Zheng Lusong; Liu Shanghua; Lei Yu

2015-01-01

Taking the steam generator of Daya Bay Nuclear Power Station as the research object, one-dimensional dynamic model of the steam generator based on drift flux theory and leak model of heat transfer tube were established. Steady simulation of steam generator under different conditions was carried out. Based on verifying the drift flux model and leak model of heat transfer tube, the effect of leak location and flow rate under different conditions on steam generator's key parameters was studied. The results show that the drift flux model and leak model can reflect the law of key parameter change accurately such as vapor mass fraction and steam pressure under different leak cases. The variation of the parameters is most apparent when the leak is at the entrance of boiling section and vapor mass fraction varies from 0.261 to 0.163 when leakage accounts for 5% of coolant flow rate. The successful prediction of the effect of heat transfer tube leak on dynamic characteristics of the steam generator based on drift flux theory supplies some references for monitoring and taking precautionary measures to prevent heat transfer tube leak accident. (authors)

Development of the double-wall-tube steam generator. Evaluation of inner tube leak detection system

International Nuclear Information System (INIS)

Teraoku, Takuji; Kisohara, Naoyuki

1995-01-01

A double-wall-tube steam generator (DWT-SG) is considered to have possibility of eliminating a secondary heat transport system to realize a reliable and simplified FBR plant. Thus, basic tests for inner/outer tube leak detection and prototypical leak tests by use of the 1MWt DWT-SG model have been performed to evaluate the feasibility of DWT-SG. Their results demonstrated that the inner leak detection system can definitely detect a steam leak from an inner tube flaw. Analyses of the inner tube leak and detection behavior obtained in the 1MWt DWT-SG test enabled to estimate the performance of the inner tube detection system of the commercial DWT-SG system. (author)

Steam generator life management

International Nuclear Information System (INIS)

Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

1998-01-01

Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

Investigations on a new internally-heated tubular packed-bed methanol–steam reformer

KAUST Repository

Nehe, Prashant; Vanteru, Mahendra Reddy; Kumar, Sudarshan

2015-01-01

Small-scale reformers for hydrogen production through steam reforming of methanol can provide an alternative solution to the demand of continuous supply of hydrogen gas for the operation of Proton Exchange Membrane Fuel Cells (PEMFCs). A packed

Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed preprocessing supply system designs

Energy Technology Data Exchange (ETDEWEB)

Muth, jr., David J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Langholtz, Matthew H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tan, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jacobson, Jacob [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwab, Amy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wu, May [Argonne National Lab. (ANL), Argonne, IL (United States); Argo, Andrew [Sundrop Fuels, Golden, CO (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cafferty, Kara [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chiu, Yi-Wen [Argonne National Lab. (ANL), Argonne, IL (United States); Dutta, Abhijit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eaton, Laurence M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Searcy, Erin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-03-31

The 2011 US Billion-Ton Update estimates that by 2030 there will be enough agricultural and forest resources to sustainably provide at least one billion dry tons of biomass annually, enough to displace approximately 30% of the country's current petroleum consumption. A portion of these resources are inaccessible at current cost targets with conventional feedstock supply systems because of their remoteness or low yields. Reliable analyses and projections of US biofuels production depend on assumptions about the supply system and biorefinery capacity, which, in turn, depend upon economic value, feedstock logistics, and sustainability. A cross-functional team has examined combinations of advances in feedstock supply systems and biorefinery capacities with rigorous design information, improved crop yield and agronomic practices, and improved estimates of sustainable biomass availability. A previous report on biochemical refinery capacity noted that under advanced feedstock logistic supply systems that include depots and pre-processing operations there are cost advantages that support larger biorefineries up to 10 000 DMT/day facilities compared to the smaller 2000 DMT/day facilities. This report focuses on analyzing conventional versus advanced depot biomass supply systems for a thermochemical conversion and refinery sizing based on woody biomass. The results of this analysis demonstrate that the economies of scale enabled by advanced logistics offsets much of the added logistics costs from additional depot processing and transportation, resulting in a small overall increase to the minimum ethanol selling price compared to the conventional logistic supply system. While the overall costs do increase slightly for the advanced logistic supply systems, the ability to mitigate moisture and ash in the system will improve the storage and conversion processes. In addition, being able to draw on feedstocks from further distances will decrease the risk of biomass supply to

Numerical Study on the Helium Flow Characteristics for Steam Generator Subsystem of HTR

International Nuclear Information System (INIS)

Ha, Jung Hoon; Ham, Jin Ki; Ki, Min-Hwan; Lee, Won Jae

2014-01-01

The High Temperature Reactor (HTR), one of the 4th generation reactors, utilizes helium as the primary coolant. A Steam Generator Subsystem (SGS) is installed to transfer heat from the primary coolant to feed water and subsequently produce steam so that it supplies electricity as well as process heat over a wide range. The SGS is composed of a helical heat exchanger, shrouds directing the flow of the shell side helium and support systems, which are located within the steam generator vessel. In this study, helium flow characteristics in the SGS were investigated at various operating conditions using Computational Fluid Dynamics (CFD). A full-scale 3-D model of the SGS was developed and the reynolds stress model with standard wall treatment was used as a turbulence model. The CFD result was compared to that of the concept design of the steam cycle modular helium reactor for the design verification of the SGS. From the CFD analysis, it was found that the primary coolant flow had non-uniform distribution while it passed the inlet in the helical heat exchanger. In order to make the uniform primary coolant flow uniform, a special type of screen was suggested in front of the helical heat exchanger. As a result, the overall design adequacy of the SGS has been evaluated. (author)

Increase of Steam Moisture in the BWR-Facility KKP 1

International Nuclear Information System (INIS)

Noack, Volker

2002-01-01

Main steam moisture in a BWR facility is determined by steam quality at core outlet and efficiency of steam separators and steam dryers. Transport of water with steam is accompanied by transport of radionuclides out of RPV resulting in enhanced radiation level in the main steam system. A remarkable increase of main steam moisture started at KKP 1 in 1997. In the following years increase of steam outlet moisture started at lower and lower core mass flow rates. Dose rate in main steam system increased simultaneously. Core mass flow rate and thus thermal power had to be reduced during stretch out operation to keep the main steam moisture below the specified boundary of 0.2 %. This boundary also guarantees, that radiological exposure remains far below approved values. The increase of main steam moisture corresponds with the application of low leakage core loading. Low leakage core loading results in enhanced steam generation in the center and in reduced steam generation in the outer zones of the core. It can be shown, that the uneven steam generation in the core became stronger over the years. Therefore, steam quality at inlet of the outer steam separators was getting lower. This resulted in higher carry over of water in this steam separators and steam dryers, thus explaining the increasing main steam moisture. KKP 1 started in 2000 with spectral shift operation. As one should expect, this resulted in reduced steam moisture. It remains the question of steam moisture in case of stretch out operation. Countermeasures are briefly discussed. (authors)

Thermal hydraulic studies in steam generator test facility

International Nuclear Information System (INIS)

Vinod, V.; Suresh Kumar, V.A.; Noushad, I.B.; Ellappan, T.R.; Rajan, K.K.; Rajan, M.; Vaidyanathan, G.

2005-01-01

Full text of publication follows: A 500 MWe fast breeder reactor is being constructed at Kalpakkam, India. This is a sodium cooled reactor with two primary and two secondary sodium loops with total 8 steam generators. The typical advantage of fast breeder plants is the high operating temperature of steam cycles and the high plant efficiency. To produce this high pressure and high temperature steam, once through straight tube vertical sodium heated steam generators are used. The steam is generated from the heat produced in the reactor core and being transported through primary and secondary sodium circuits. The steam generator is a 25 m high middle supported steam generator with expansion bend and 23 m heat transfer length. Steam Generator Test Facility (SGTF) constructed at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam aims at performing various tests on a 5.5 MWt steam generator. This vertically simulated test article is similar in all respects to the proposed 157 MWt steam generator module for the Prototype Fast Breeder Reactor (PFBR), with reduced number of tubes. Heat transfer performance tests are done with this 19 tube steam generator at various load conditions. Sodium circuit for the SGTF is equipped with oil fired heater as heat source and centrifugal sodium pump, to pump sodium at 105 m 3 /hr flow rate. Other typical components like sodium to air heat exchanger, sodium purification system and hydrogen leak detection system is also present in the sodium circuit. High pressure steam produced in the steam generator is dumped in a condenser and recycled. Important tests planned in SGTF are the heat transfer performance test, stability test, endurance test and performance test of steam generator under various transients. The controlled operation of steam generator will be studied with possible control schemes. A steady state simulation of the steam generator is done with a mathematical model. This paper gives the details of heat transfer

Methods of thermal power extraction from nuclear sources for meeting the consumer system demands

International Nuclear Information System (INIS)

Sellej, J.

1985-01-01

The technical design is discussed of heat extraction from nuclear power plants and heating plants. Variant technical designs are discussed of hot water and steam supply, including the basic aspects of nuclear safety. Hot water supplies are technically provided by heat exchanger units connected to turbines, or by heating turbines. The advantages and disadvantages of the two designs are discussed. The possibility of heat extraction by steam from the nuclear power plant is provided by steam exchangers, i.e., steam exchanger cascades, the so-called inserted steam circuit. Supplies of steam from nuclear sources, as against supplies of hot water have not yet been technically resolved with regard to safety, design and economic benefit. Nuclear heating plants have also been designed for hot water supply, but not yet for steam supply. (Pu)

The role of enterprise systems in supply chain networks: a taxonomy of supply chain strategies

DEFF Research Database (Denmark)

Møller, Charles

2006-01-01

in the supply chain and to choose the right supply chain strategy. The work is based on a comprehensive study of the Supply Chain Management (SCM) and Enterprise Resource Planning (ERP) literature and the study suggests that there is an emerging new research potential for Enterprise Systems (ES) in the supply......This paper proposes a taxonomy for supply chain integration strategies. The taxonomy is based on the contingencies of supply chain network coupling and the Extended Enterprise Systems (EES) architecture in the supply chain. The purpose of this model is to map the portfolio of relations...

Digital simulation for nuclear once-through steam generators

International Nuclear Information System (INIS)

Chen, A.T.

1976-01-01

Mathematical models for calculating the dynamic response of the Oconee type once through steam generator (OTSG) and the integral economizer once through steam generator (IEOTSG) was developed and presented in this dissertation. Linear and nonlinear models of both steam generator types were formulated using the state variable, lumped parameter approach. Transient and frequency responses of system parameters were calculated for various perturbations from both the primary coolant side and the secondary side. Transients of key parameters, including primary outlet temperature, superheated steam outlet temperature, boiling length/subcooled length and steam pressure, were generated, compared and discussed for both steam generator types. Frequency responses of delta P/sub s//deltaT/sub pin/ of the linear OTSG model were validated by using the dynamic testing results obtained at the Oconee I nuclear power station. A sensitivity analysis in both the time and the frequency domains was performed. It was concluded that the mathematical and computer models developed in this dissertation for both the OTSG and the IEOTSG are suitable for overall plant performance evaluation and steam generator related component/system design analysis for nuclear plants using either type of steam generator

Steam generator replacement in Bruce A Unit 1 and Unit 2

International Nuclear Information System (INIS)

Hart, R.S.

2007-01-01

The Bruce A Generating Station consists of four 900 MW class CANDU units. The reactor and Primary Heat Transport System for each Unit are housed within a reinforced concrete reactor vault. A large duct running below the reactor vaults accommodates the shared fuel handling system, and connects the four reactor vaults to the vacuum building. The reactor vaults, fuelling system duct and the vacuum building constitute the station vacuum containment system. Bruce A Unit 2 was shut down in 1995 and Bruce A Units 1, 3 and 4 were shutdown in 1997. Bruce A Units 3 and 4 were returned to service in late 2003 and are currently operating. Units 1 and 2 remain out of service. Bruce Power is currently undertaking a major rehabilitation of Bruce A Unit 1 and Unit 2 that will extend the in-service tile of these units by at least 25 years. Replacement of the Steam Generators (eight in each unit) is required; this work was awarded to SNC-Lavalin Nuclear (SLN). The existing steam drums (which house the steam separation and drying equipment) will be retained. Unit 2 is scheduled to be synchronized with the grid in 2009, followed by Unit 1 in 2009. Each Bruce A unit has two steam generating assemblies, one located above and to each end of the reactor. Each steam generating assembly consists of a horizontal cylindrical steam drum and four vertical Steam Generators. The vertical Steam Generators connect to individual nozzles that are located on the underside of the Steam Drum (SD). The steam drums are located in concrete shielding structures (steam drum enclosures). The lower sections of the Steam Generators penetrate the top of the reactor vaults: the containment pressure boundary is established by bellows assemblies that connect between the reactor vault roof slab and the Steam Generators. Each Steam Generators is supported from he bottom by a trapeze that is suspended from the reactor vault top structure. The Steam Generator Replacement (SGR) methodology developed by SLN for Unit 1

Determination of moisture content in steams and variation in moisture content with operating boiler level by analyzing sodium content in steam generator water and steam condensate of a nuclear power plant using ion chromatographic technique

International Nuclear Information System (INIS)

Pal, P.K.; Bohra, R.C.

2015-01-01

Dry steam with moisture content less than <1% is the stringent requirements in a steam generator for good health of the turbine. In order to confirm the same, determination of sodium is done in steam generator water and steam condensate using Flame photometer in ppm level and ion chromatograph in ppb level. Depending on the carry over of sodium in steam along with the water droplet (moisture), the moisture content in steam was calculated and was found to be < 1% which is requirements of the system. The paper described the salient features of a PHWR, principle of Ion Chromatography, chemistry parameters of Steam Generators and calculation of moisture content in steam on the basis of sodium analysis. (author)

Does a new steam meal catering system meet patient requirements in hospital?

Science.gov (United States)

Hickson, M; Fearnley, L; Thomas, J; Evans, S

2007-10-01

It has been consistently observed that a significant proportion of hospital inpatients are malnourished and many actually develop malnutrition in hospital. The NHS provides over 300 million meals each year at a cost of pound 500 million, yet there is relatively little research evaluating how well different catering systems provide for the needs of hospital inpatients. The aim of the study was to: (i) evaluate whether a new steam meal catering system (Steamplicity) enables patients in theory to meet their energy requirements in hospital and (ii) compare energy and protein intake using Steamplicity with a traditional bulk cook-chill system. Patients not at nutritional risk had their food intake at one lunchtime assessed. Energy intake was compared with the patients' energy requirements and energy and protein intake were compared with previous data from a bulk system. Fifty-seven patients had a median daily energy requirement of 7648 kJ (1821 kcal) [inter-quartile range (IQR): 6854-9164 kJ]. Assuming 30% [2293 kJ (546 kcal)] should be supplied by the lunch meal the average intake of 1369 kJ (326 kcal) fell short by 40%. Patients served meals from Steamplicity ate less energy [1369 kJ versus 1562 kJ (326 kcal versus 372 kcal) P = 0.04] but similar protein (18 g versus 19 g P = 0.34) to the bulk system. The largest difference was the energy provided by the dessert since the bulk system served more hot high-calorie desserts. Patient intakes did not meet their estimated requirements. The patients in this study were eating well and not at nutritional risk, thus patients with a poor appetite will be even less likely to meet their nutritional requirements. Steamplicity meals result in a lower energy intake than meals from a bulk cook-chill system, but similar protein intakes.

Proposal and assessment of a novel integrated CCHP system with biogas steam reforming using solar energy

International Nuclear Information System (INIS)

Su, Bosheng; Han, Wei; Jin, Hongguang

2017-01-01

Highlights: •A novel CCHP system with biogas steam reforming using solar energy is raised. •Chemical and physical energy of biogas is efficiently used in a cascaded way. •The energy quality of concentrating solar heat is promoted in the system. •A parametric analysis is adopted to optimize the thermodynamic performance. •A typical-day study is conducted to explore the general operation features. -- Abstract: The conventional way to utilize biogas either is energy-intensive due to biogas upgrading or causes huge waste of energy grade and environmental pollution by direct burning. This paper proposes a biogas and solar energy-assisted combined cooling, heating and power (BSCCHP) system that upgrades the caloric value of biogas before combustion by introducing a thermochemical conversion process that is driven by solar heat. Adopting commercially established technologies including steam reforming and parabolic dish concentrators, the system exhibits an enhanced system exergy efficiency, and the technology considerably reduces the direct CO 2 footprint and saves depletable fossil fuel. With a solar thermal share of 22.2%, the proposed system not only has a high net solar-to-product thermal and exergy efficiency of 46.80% and 26.49%, respectively, but also results in a commensurate 18.27% reduction of the direct CO 2 footprint compared with the reference individual systems. The effect of critical parameters in the biogas steam reforming process on the system performance was studied. A proper selection of the steam/carbon ratio leads to the optimal direct CO 2 footprint and system exergy efficiency. Pursuing a very high conversion of biogas by improving the reforming temperature is not a wise choice from a system perspective. Finally, a typical-day dynamic simulation was conducted to preliminarily explore the general operation features. This study may provide a new way to efficiently use the renewable energy in the distributed energy system.

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.

Supply system with microprocessor control for electron gun

International Nuclear Information System (INIS)

Duplin, N.I.; Sergeev, N.N.

1988-01-01

Precision supply system for electron gun used in Auger-spectrometer is described. The supply system consists of control and high-voltage parts, made as separate units. Supply high-voltage unit includes system supply module, filament module to supply electron gun cathode and 6 high-volt modules to supply accelerating, modulating and three focusing electrodes of the gun. High-voltage modules have the following characteristics: U-(100-1000)V output voltage, 5x10 -5 U stability, 10 -5 xU pulsation amplitude, J-(0-5)A filament current change range at 10 -4 xJ stability. Control unit including microprocessor, timer and storage devices forms control voltage for all modules and regulates voltage and current of filament at electrodes

Steam generator replacement in Bruce A Unit 1 and Unit 2

International Nuclear Information System (INIS)

Hart, R.S.

2006-01-01

The Bruce A Generating Station consists of four 900 MW class CANDU units. The reactor and Primary Heat Transport System for each Unit are housed within a reinforced concrete reactor vault. A large duct running below the reactor vaults accommodates the shared fuel handling system, and connects the four reactor vaults to the vacuum building. The reactor vaults, fuelling system duct and the vacuum building constitute the station vacuum containment system. Bruce A Unit 2 was shut down in 1995 and Bruce A Units 1, 3 and 4 were shutdown in 1997. Bruce A Units 3 and 4 were returned to service in late 2003 and are currently operating. Units 1 and 2 remain out of service. Bruce Power is currently undertaking a major rehabilitation of Bruce A Unit 1 and Units 2 that will extend the in-service life of these units by at least 25 years. Replacement of the Steam Generators (eight in each unit) is required; this work was awarded to SNC-Lavalin Nuclear (SLN). The existing steam drums (which house the steam separation and drying equipment) will be retained. Unit 2 is scheduled to be synchronized with the grid in 2009, followed by Unit 1 in 2009. Each Bruce A unit has two steam generating assemblies, one located above and to each end of the reactor. Each steam generating assembly consists of a horizontal cylindrical steam drum and four vertical Steam Generators. The vertical Steam Generators connect to individual nozzles that are located on the underside of the Steam Drum (SD). The steam drums are located in concrete shielding structures (steam drum enclosures). The lower sections of the Steam Generators penetrate the top of the reactor vaults: the containment pressure boundary is established by bellows assemblies that connect between the reactor vault roof slab and the Steam Generators. Each Steam Generators is supported from the bottom by a trapeze that is suspended from the reactor vault top structure. The Steam Generator Replacement (SGR) methodology developed by SLN for Unit 1

The condition monitoring system of turbine system components for nuclear power plants

International Nuclear Information System (INIS)

Ono, Shigetoshi

2013-01-01

The thermal and nuclear power plants have been imposed a stable supply of electricity. To certainly achieve this, we built the plant condition monitoring system based on the heat and mass balance calculation. If there are some performance changes on the turbine system components of their power plants, the heat and mass balance of the turbine system will change. This system has ability to detect the abnormal signs of their components by finding the changes of the heat and mass balance. Moreover we note that this system is built for steam turbine cycle operating with saturated steam conditions. (author)

An Improved Steam Injection Model with the Consideration of Steam Override

OpenAIRE

He , Congge; Mu , Longxin; Fan , Zifei; Xu , Anzhu; Zeng , Baoquan; Ji , Zhongyuan; Han , Haishui

2017-01-01

International audience; The great difference in density between steam and liquid during wet steam injection always results in steam override, that is, steam gathers on the top of the pay zone. In this article, the equation for steam override coefficient was firstly established based on van Lookeren’s steam override theory and then radius of steam zone and hot fluid zone were derived according to a more realistic temperature distribution and an energy balance in the pay zone. On this basis, th...

Advanced marine reactor MRX and application to nuclear barge supplying electricity and heat

International Nuclear Information System (INIS)

Ishida, Toshihisa; Kusunoki, Tsuyoshi; Odano, Naoteru; Yoritsune, Tsutomu; Fukuhara, Yoshifumi; Ochiai, Masa-aki

2000-01-01

The basic design concept of an advanced marine reactor MRX has been established with adoption of several new technologies. The MRX is an integral-type PWR with 100 MWt aimed basically for use of ship propulsion. Adoption of a water-filled containment together with the integral type reactor makes the reactor light-weight and compact greatly. A engineered safety system is a simplified passive system, function of which is confirmed by the safety analysis. The MRX can be applied to an energy supply system of electricity and heat co-generation by installing it on a barge. Concept of a nuclear barge with the MRX of 334 MWt output is presented for use of supplying electricity, fresh water and hot water. Combined system of electric generation and desalination with the RO process can deliver variable output of electricity and fresh water according a demand. Latent heat of the exhausted steam from the turbine can be used effectively to raise the temperature of cold water as heat supply. (author)

Modeling and optimization of a utility system containing multiple extractions steam turbines

International Nuclear Information System (INIS)

Luo, Xianglong; Zhang, Bingjian; Chen, Ying; Mo, Songping

2011-01-01

Complex turbines with multiple controlled and/or uncontrolled extractions are popularly used in the processing industry and cogeneration plants to provide steam of different levels, electric power, and driving power. To characterize thermodynamic behavior under varying conditions, nonlinear mathematical models are developed based on energy balance, thermodynamic principles, and semi-empirical equations. First, the complex turbine is decomposed into several simple turbines from the controlled extraction stages and modeled in series. THM (The turbine hardware model) developing concept is applied to predict the isentropic efficiency of the decomposed simple turbines. Stodola's formulation is also used to simulate the uncontrolled extraction steam parameters. The thermodynamic properties of steam and water are regressed through linearization or piece-wise linearization. Second, comparison between the simulated results using the proposed model and the data in the working condition diagram provided by the manufacturer is conducted over a wide range of operations. The simulation results yield small deviation from the data in the working condition diagram where the maximum modeling error is 0.87% among the compared seven operation conditions. Last, the optimization model of a utility system containing multiple extraction turbines is established and a detailed case is analyzed. Compared with the conventional operation strategy, a maximum of 5.47% of the total operation cost is saved using the proposed optimization model. -- Highlights: → We develop a complete simulation model for steam turbine with multiple extractions. → We test the simulation model using the performance data of commercial turbines. → The simulation error of electric power generation is no more than 0.87%. → We establish a utility system operational optimization model. → The optimal industrial operation scheme featured with 5.47% of cost saving.

PROFIL-360 high resolution steam generator tube profilometry system

International Nuclear Information System (INIS)

Glass, S.W.

1985-01-01

A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

Profil-360 high resolution steam generator tube profilometry system

International Nuclear Information System (INIS)

Glass, S.W.

1985-01-01

A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

Constraints on silicates formation in the Si-Al-Fe system: Application to hard deposits in steam generators of PWR nuclear reactors

Science.gov (United States)

Berger, Gilles; Million-Picallion, Lisa; Lefevre, Grégory; Delaunay, Sophie

2015-04-01

Introduction: The hydrothermal crystallization of silicates phases in the Si-Al-Fe system may lead to industrial constraints that can be encountered in the nuclear industry in at least two contexts: the geological repository for nuclear wastes and the formation of hard sludges in the steam generator of the PWR nuclear plants. In the first situation, the chemical reactions between the Fe-canister and the surrounding clays have been extensively studied in laboratory [1-7] and pilot experiments [8]. These studies demonstrated that the high reactivity of metallic iron leads to the formation of Fe-silicates, berthierine like, in a wide range of temperature. By contrast, the formation of deposits in the steam generators of PWR plants, called hard sludges, is a newer and less studied issue which can affect the reactor performance. Experiments: We present here a preliminary set of experiments reproducing the formation of hard sludges under conditions representative of the steam generator of PWR power plant: 275°C, diluted solutions maintained at low potential by hydrazine addition and at alkaline pH by low concentrations of amines and ammoniac. Magnetite, a corrosion by-product of the secondary circuit, is the source of iron while aqueous Si and Al, the major impurities in this system, are supplied either as trace elements in the circulating solution or by addition of amorphous silica and alumina when considering confined zones. The fluid chemistry is monitored by sampling aliquots of the solution. Eh and pH are continuously measured by hydrothermal Cormet© electrodes implanted in a titanium hydrothermal reactor. The transformation, or not, of the solid fraction was examined post-mortem. These experiments evidenced the role of Al colloids as precursor of cements composed of kaolinite and boehmite, and the passivation of amorphous silica (becoming unreactive) likely by sorption of aqueous iron. But no Fe-bearing was formed by contrast to many published studies on the Fe

Maintenance and repair of LMFBR steam generators

International Nuclear Information System (INIS)

Verriere, P.; Alanche, J.; Minguet, J.L.

1984-06-01

After some general remarks on the French fast neutron system, this paper presents the state of the program for the construction of fast reactor in France. Then, the general design of Super Phenix 1 steam generator components is outlined and, the in-service monitoring systems and protective devices with which they are equiped are briefly described. The methods used, in the event of leakage, for leak location, steam generator inspection, steam generator repair and putting the affected loop back into service, are discussed. There are two main lines of research, relating respectively to the means of water leak detection in sodium and the inspection arrangements that will be used either periodically, or following a sodium-water reaction. Finally, after a brief description of the steam generator, this paper describes the four incidents (leaks) that occurred on the Phenix steam generator in the course of 1982 and 1983, and the subsequent repair operations

The performance of a temperature cascaded cogeneration system producing steam, cooling and dehumidification

KAUST Repository

Myat, Aung

2013-02-01

This paper discusses the performance of a temperature-cascaded cogeneration plant (TCCP), equipped with an efficient waste heat recovery system. The TCCP, also called a cogeneration system, produces four types of useful energy-namely, (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification-by utilizing single fuel source. The TCCP comprises a Capstone C-30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste-heat-activated devices, namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The performance analysis was conducted under different operation conditions such as different exhaust gas temperatures. It was observed that energy utilization factor could be as high as 70% while fuel energy saving ratio was found to be 28%. © 2013 Desalination Publications.

Improving Steam System Performance: A Sourcebook for Industry, Second Edition (Book) (Revised)

Energy Technology Data Exchange (ETDEWEB)

2012-10-01

Improving Steam System Performance: A Sourcebook for Industry was developed for the U.S. Department of Energy's (DOE) Advanced Manufacturing Office (AMO), formerly the Industrial Technologies Program. AMO undertook this project as a series of sourcebook publications. Other topics in this series include: compressed air systems, pumping systems, fan systems, process heating and motor and drive systems. For more information about program resources, see AMO in the Where to Find Help section of this publication.

Coupling of a 2.5 kW steam reformer with a 1 kW el PEM fuel cell

Science.gov (United States)

Mathiak, J.; Heinzel, A.; Roes, J.; Kalk, Th.; Kraus, H.; Brandt, H.

The University of Duisburg-Essen has developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. This steam reformer was combined with a polymer electrolyte membrane fuel cell (PEM FC) and a system test of the process chain was performed. The fuel processor comprises a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PROX) as CO purification. The fuel processor is designed to deliver a thermal hydrogen power output from 500 W to 2.5 kW. The PEM fuel cell stack provides about 1 kW electrical power. In the following paper experimental results of measurements of the single components PEM fuel cell and fuel processor as well as results of the coupling of both to form a process chain are presented.

Development of a simulation platform for dynamic simulation and control studies of AP1000 nuclear steam supply system

International Nuclear Information System (INIS)

Wan, Jiashuang; Song, Hongbing; Yan, Shoujun; Sun, Jian; Zhao, Fuyu

2015-01-01

Highlights: • A fast-running simulation platform named NCAP was developed on a personal computer using MATLAB/Simulink. • Three types of typical operations, namely 10% step load change, 5%/min ramp load change and load follow were simulated. • NCAP predictions were compared with those obtained by CENTS for the load regulation transients. - Abstract: This paper presents the development, application and performance assessment of a fast-running NCAP (NSSS Control & Analysis Platform) in MATLAB/Simulink environment. First, a nodal core model, a lumped parameter dynamic steam generator model with moving boundary, a non-equilibrium two-regions-three-volumes pressurizer model, and the relevant pipe and plenum models were proposed based on the fundamental conservation of mass, energy and momentum. Then, these first order nonlinear models and the NSSS control systems were implemented in the Simulink by the predefined library blocks. Based on the developed NCAP, three types of typical operational transients, namely the 10% step load change, the 5%/min ramp load change and the daily load follow were simulated to study the dynamic behavior and control characteristics of the AP1000 NSSS. It has been demonstrated that the dynamic responses of the selected key parameters agree well with the general physical rules. In addition, the comparison of load regulation simulation results obtained by NCAP and CENTS shows a good agreement in terms of the changing trends. With the adoption of modular programming techniques, the NCAP facilitates easy modification and runs quickly, which easily allows the control system designer to test and compare various ideas efficiently

Condition monitoring of steam turbo generators of captive power plant at HWP (Manuguru) through vibration analysis

International Nuclear Information System (INIS)

Krishnareddy, G.; Chandramouli, M.; Gupta, R.V.

2002-01-01

Turbo Generator is a critical equipment in steam based power plant circuit. Any failure causes loss of production and hence as applicable to Heavy Water Plant, Manuguru, it results in loss of heavy water production as the captive power plant at Manuguru is solely designed to supply steam and power to Main Plant, which is meant for production of heavy water. Thereby condition monitoring is very much essential and required as part of predictive maintenance program for the turbo generators which are in continuous operation. This paper focuses on identification of the turbo generator system through vibration spectrum, characterising and differentiating the fault mechanisms, trending the faults through changes in vibration spectrums and orbit plots and subsequently planning for corrective actions/measures after evaluating the changes in machine conditions

49 CFR 230.108 - Steam locomotive leading and trailing trucks.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive leading and trailing trucks. 230... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Trucks, Frames and Equalizing System § 230.108 Steam locomotive leading...

Dismantling of the 50 MW steam generator test facility

International Nuclear Information System (INIS)

Nakai, S.; Onojima, T.; Yamamoto, S.; Akai, M.; Isozaki, T.; Gunji, M.; Yatabe, T.

1997-01-01

We have been dismantling the 50MW Steam Generator Test Facility (50MWSGTF). The objectives of the dismantling are reuse of sodium components to a planned large scale thermal hydraulics sodium test facility and the material examination of component that have been operated for long time in sodium. The facility consisted of primary sodium loop with sodium heater by gas burner as heat source instead of reactor, secondary sodium loop with auxiliary cooling system (ACS) and water/steam system with steam temperature and pressure reducer instead of turbine. It simulated the 1 loop of the Monju cooling system. The rated power of the facility was 50MWt and it was about 1/5 of the Monju power plant. Several sodium removal methods are applied. As for the components to be dismantled such as piping, intermediate heat exchanger (IHX), air cooled heat exchangers (AC), sodium is removed by steam with nitrogen gas in the air or sodium is burned in the air. As for steam generators which material tests are planned, sodium is removed by steam injection with nitrogen gas to the steam generator. The steam generator vessel is filled with nitrogen and no air in the steam generator during sodium removal. As for sodium pumps, pump internal structure is pulled out from the casing and installed into the tank. After the installation, sodium is removed by the same method of steam generator. As for relatively small reuse components such as sodium valves, electromagnet flow meters (EMFs) etc., sodium is removed by alcohol process. (author)

Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed pre-processing supply system designs

Energy Technology Data Exchange (ETDEWEB)

David J. Muth, Jr.; Matthew H. Langholtz; Eric C. D. Tan; Jacob J. Jacobson; Amy Schwab; May M. Wu; Andrew Argo; Craig C. Brandt; Kara G. Cafferty; Yi-Wen Chiu; Abhijit Dutta; Laurence M. Eaton; Erin M. Searcy

2014-08-01

The 2011 US Billion-Ton Update estimates that by 2030 there will be enough agricultural and forest resources to sustainably provide at least one billion dry tons of biomass annually, enough to displace approximately 30% of the country's current petroleum consumption. A portion of these resources are inaccessible at current cost targets with conventional feedstock supply systems because of their remoteness or low yields. Reliable analyses and projections of US biofuels production depend on assumptions about the supply system and biorefinery capacity, which, in turn, depend upon economic value, feedstock logistics, and sustainability. A cross-functional team has examined combinations of advances in feedstock supply systems and biorefinery capacities with rigorous design information, improved crop yield and agronomic practices, and improved estimates of sustainable biomass availability. A previous report on biochemical refinery capacity noted that under advanced feedstock logistic supply systems that include depots and pre-processing operations there are cost advantages that support larger biorefineries up to 10 000 DMT/day facilities compared to the smaller 2000 DMT/day facilities. This report focuses on analyzing conventional versus advanced depot biomass supply systems for a thermochemical conversion and refinery sizing based on woody biomass. The results of this analysis demonstrate that the economies of scale enabled by advanced logistics offsets much of the added logistics costs from additional depot processing and transportation, resulting in a small overall increase to the minimum ethanol selling price compared to the conventional logistic supply system. While the overall costs do increase slightly for the advanced logistic supply systems, the ability to mitigate moisture and ash in the system will improve the storage and conversion processes. In addition, being able to draw on feedstocks from further distances will decrease the risk of biomass supply to

CANDU steam generator life management

International Nuclear Information System (INIS)

Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

1998-01-01

Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermalhydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. The research and development program, as well as operating experience, has identified where improvements in operating practices and/or designs can be made in order to ensure steam generator design life at an acceptable capacity factory. (author)

Availability of steam generator against thermal disturbance of hydrogen production system coupled to HTGR

International Nuclear Information System (INIS)

Shibata, Taiju; Nishihara, Tetsuo; Hada, Kazuhiko; Shiozawa, Shusaku

1996-01-01

One of the safety issues to couple a hydrogen production system to an HTGR is how the reactor coolability can be maintained against anticipated abnormal reduction of heat removal (thermal disturbance) of the hydrogen production system. Since such a thermal disturbance is thought to frequently occur, it is desired against the thermal disturbance to keep reactor coolability by means other than reactor scram. Also, it is thought that the development of a passive cooling system for such a thermal disturbance will be necessary from a public acceptance point of view in a future HTGR-hydrogen production system. We propose a SG as the passive cooling system which can keep the reactor coolability during a thermal disturbance of a hydrogen production system. This paper describes the proposed steam generator (SG) for the HTGR-hydrogen production system and a result of transient thermal-hydraulic analysis of the total system, showing availability of the SG against a thermal disturbance of the hydrogen production system in case of the HTTR-steam reforming hydrogen production system. (author)

Experimental investigation of non-condensable gases effect on operation of VVER steam generator in condensation mode

International Nuclear Information System (INIS)

Efanov, A. D.; Kalyakin, S. G.; Morozov, A. V.; Remizov, O. V.; Tsyganok, A. A.; Generalov, V. N.; Berkovich, V. M.; Taranov, G. S.

2008-01-01

To provide the safety in new Russian NPP designs, protection passive systems which don't depend upon human errors are widely used. In terms of safety, the design of NPP of new generation (NPP-2006) falls into the class of advanced NPPs. In the event of an beyond design basis accident with the rupture of the reactor primary circuit and accompanied by the loss of ac sources, the use of passive safety systems are provided for necessary core cooling. Among these is passive heat removal system (PHRS). In the case of leakage in the primary circuit this system ensures the transition of steam generators (SG) to operation in the mode of condensation of the primary circuit steam coming to SG piping from the reactor. As a result, the condensate from steam generators arrives at the core providing its additional cooling. The SG condensation capacity can be adversely affected by the presence of non-condensable gases in the primary circuit of the reactor. Their main sources are nitrogen arriving at the circuit, as hydro accumulators actuate, products of radiolysis of water and air drawn in from the containment through the pipeline rupture. The accumulation of non-condensable gases in SG piping can result in degradation of its condensation capacity to the extent that condensation completely terminates. In this case, the core cooling conditions may be impaired. To experimental investigation of the condensation mode of operation of WER steam generator, a large scale HA2M-SG test rig was constructed at the SSC RF IPPE. The test rig incorporates: buffer tank, equipped by steam supply system; SG model with volumetric-power scale is 1:46; PHRS heat exchanger imitator, cooling by process water. The rig main equipment connected by pipelines and equipped by valves. The elevations of the main equipment correspond to those of reactor project. The rig maximum operating parameters: steam pressure - 1.6 MPa, temperature - 200 Celsius degrees. Experiments at the HA2M-SG test rig have been

Optimal sampling period of the digital control system for the nuclear power plant steam generator water level control

International Nuclear Information System (INIS)

Hur, Woo Sung; Seong, Poong Hyun

1995-01-01

A great effort has been made to improve the nuclear plant control system by use of digital technologies and a long term schedule for the control system upgrade has been prepared with an aim to implementation in the next generation nuclear plants. In case of digital control system, it is important to decide the sampling period for analysis and design of the system, because the performance and the stability of a digital control system depend on the value of the sampling period of the digital control system. There is, however, currently no systematic method used universally for determining the sampling period of the digital control system. Generally, a traditional way to select the sampling frequency is to use 20 to 30 times the bandwidth of the analog control system which has the same system configuration and parameters as the digital one. In this paper, a new method to select the sampling period is suggested which takes into account of the performance as well as the stability of the digital control system. By use of the Irving's model steam generator, the optimal sampling period of an assumptive digital control system for steam generator level control is estimated and is actually verified in the digital control simulation system for Kori-2 nuclear power plant steam generator level control. Consequently, we conclude the optimal sampling period of the digital control system for Kori-2 nuclear power plant steam generator level control is 1 second for all power ranges. 7 figs., 3 tabs., 8 refs. (Author)

Digital control system of a steam generator water level by LQG optimal method

International Nuclear Information System (INIS)

Lee, Yoon Joon

1993-01-01

A digital control system for the steam generator water level control is developed using LQG optimal design method. To describe the more realistic situaton, a feedwater valve actuator is assumed to be of the first order lagger and is included in the overall control system. By composing the digital control circuit in such a way that the overall control system consists of two sub-systems of feedwater station and feedback loop digital controller, the design procedure is divided into two independent steps. The feedwater station system is described in the error dynamics of an ordinary regulator system. The optimal gains are obtained by LQ method which imposes the constraints of the feedwater valve motion as well as on the output deviations. Developed also is a Kalman observer on account of the flow measurement uncertainty at low power. Then a digital controller on the feedback loop is designed so that the system maintains the same stability margins for all power ranges. The simulation results show thst the optimal digital system has a good control characteristics despite the adverse dynamics of a steam generator at low power. (Author)

Future aspects for liquid metal heated steam generators

International Nuclear Information System (INIS)

Jansing, W.; Ratzel, W.; Vinzens, K.

1975-01-01

The present status of steam generators is shown. The experience gained until now is expressed in form of basic points. The most important design criteria for steam generator systems are outlined. On the basis of these design criteria, two possible steam generator concepts are shown. Costs in relationship to the repair concepts of two modular steam generators (thermal output 156 and 625 MW) and a pool design of 625 MW are compared. (author)

Future aspects for liquid metal heated steam generators

Energy Technology Data Exchange (ETDEWEB)

Jansing, W; Ratzel, W; Vinzens, K

1975-07-01

The present status of steam generators is shown. The experience gained until now is expressed in form of basic points. The most important design criteria for steam generator systems are outlined. On the basis of these design criteria, two possible steam generator concepts are shown. Costs in relationship to the repair concepts of two modular steam generators (thermal output 156 and 625 MW) and a pool design of 625 MW are compared. (author)

Acoustic detection for water/steam leak from a tube of LMFBR steam generator

International Nuclear Information System (INIS)

Sonoda, Masataka; Shindo, Yoshihisa

1989-01-01

Acoustic leak detector is useful for detecting more quickly intermediate leak than the existing hydrogen detector and is available for identification of leak location on the accident of water/steam leak from a tube of LMFBR steam generator. This paper presents the overview of HALD (High frequency Acoustics Leak Detection) system, which is more sensitive for leak detection and lower cost of equipment for identification of leak location than a low frequency type detector. (author)

A steam superheater exchanger provided with two coaxial casings and an horizontal axis

International Nuclear Information System (INIS)

Marjollet, Jacques; Palacio, Gerard; Tondeur, Gerard.

1976-01-01

This invention concerns the general lay-out of an horizontal axis separator-superheater for supplying steam to a high power turbine, particularly for a nuclear power station. The invention significantly reduces the length of the pipework connecting the superheated steam outlet and its inlet to the turbine. For this, the outer casing is provided with a coaxial internal annular sleeve in which are housed, one above the other, the separator and the bundle of superheater tubes through which circulates the water emulsion to be separated and steam to be superheated. At the end of its treatment, the superheated steam spreads out in the space between the sleeve and the outer casing from whence it can be drawn off at any point of its periphery, thus making it possible to choose an extraction point as near as possible to the inlet of the turbine to be fed [fr

Accelerator-control-system interface for intelligent power supplies

International Nuclear Information System (INIS)

Cohen, S.

1992-01-01

A number of high-current high-precision magnet power supplies have been installed at the proton storage ring at the Los Alamos National Laboratory Accelerator Complex. The units replace existing supplies, powering large dipole magnets in the ring. These bending magnets require a high-current supply that is precise and stable. The control and interface design for these power supplies represents a departure from all others on-site. The supplies have sophisticated microprocessor control on-board and communicate with the accelerator control system via RS-422 (serial communications). The units, built by Alpha Scientific Electronics, Hayward, CA use a high-level ASCII control protocol. The low-level ''front-end'' software used by the accelerator control system has been written to accommodate these new devices. They communicate with the control system through a terminal server port connected to the site-wide ethernet backbone. Details of the software implementation for the analog and digital control of the supplies through the accelerator control system will be presented

System Dynamics Modeling for Supply Chain Information Sharing

Science.gov (United States)

Feng, Yang

In this paper, we try to use the method of system dynamics to model supply chain information sharing. Firstly, we determine the model boundaries, establish system dynamics model of supply chain before information sharing, analyze the model's simulation results under different changed parameters and suggest improvement proposal. Then, we establish system dynamics model of supply chain information sharing and make comparison and analysis on the two model's simulation results, to show the importance of information sharing in supply chain management. We wish that all these simulations would provide scientific supports for enterprise decision-making.

Calculation Method of Steam Generator Level for swelling and shrinking effects in YGN 1/2 Simulator

International Nuclear Information System (INIS)

Hwang, Do Hyun; Seo, In Yong; Park, Weon Seo; Suh, Jae Seung

2007-01-01

In August 2006, the development of new simulator for YGN 1/2 Simulator was completed. The NSSS (Nuclear Steam Supply System) T/H(Thermal- Hydraulic) module in this simulator was developed with ARTS code based on RETRAN, which is a best estimate thermal-hydraulic code designed to analyze several operational transients by EPRI(Electric Power Research Institute). RETRAN, however, has some limitations in real-time calculation capability and its robustness to be used in the simulator for some transient conditions. To overcome these limitations, its robustness and real-time calculation capability have been improved with simplifications and removing of discontinuities of the physical correlations of the RETRAN code. And some supplements are also developed to extend its simulation scope of the ARTS code. In comparison to KNPEC(Kori Nuclear Power Education Center) no.2 simulator, the simulator based on Younggwang Unit 1 developed in the year 2001, the ARTS code was upgraded that it extended its calculating region to the steam line and common header before turbine while it had calculated to the steam generator exit before steam line in KNPEC no.2 simulator. Consequently, the number of volume and fill/normal junction in ARTS nodalization increased to 109 and 174 from 62 and 125, respectively

Integrated energy systems for hydrogen and electricity supply

Energy Technology Data Exchange (ETDEWEB)

Muradov, N. [Univ. of Central Florida, Cocoa, FL (United States). Florida Solar Energy Center; Manikowski, A.; Noland, G. [Procyon Power Systems Inc., Alameda, CA (United States)

2002-07-01

The United States will soon need an increase in electric generating capacity along with an increase in the distribution capacity of the electricity grid. The cost and time required to build additional electrical distribution and transmission systems can be avoided by using distributed power generation. This paper examines the development of an integrated stand-alone energy system that can produce hydrogen, electricity and heat. The concept is based on integrated operation of a thermocatalytic pyrolysis (TCP) reactor and a solid oxide fuel cell (SOFC). The benefits include high overall energy efficiency, the production of high quality hydrogen (90 to 95 per cent free of carbon oxides), low emissions, and fuel flexibility. Experimental data is presented regarding the thermocatalytic pyrolysis of methane compared with an iron-based catalyst (which is sulfur resistant) and gasification of the resulting carbon with steam and carbon dioxide. With distributed generation, additional electrical generating capacity can be added in small increments distributed over the grid. An integrated energy system will be applicable to any type of hydrocarbon fuel, such as natural gas, liquid propane gas, gasoline, kerosene, jet fuel, diesel fuel and sulfurous residual oils. The suitable range of operating parameters needed to decoke a catalyst bed using steam and carbon dioxide as a degasifying agent was also determined. The Fe-catalyst was efficient in both methane pyrolysis and steam/CO{sub 2} gasification of carbon. It was shown that the TCP and SOFC complement each other in may ways. With the IES, high quality hydrogen is delivered to the end user. IES can also operate as either a hydrogen production unit or as an electrical power generator. The energy efficiency of the IES is estimated at 45-55 per cent. 6 refs., 8 figs.

Infrared technique for measuring steam density

International Nuclear Information System (INIS)

Snyder, S.C.; Baker, A.G.

1982-01-01

A prototype infrared steam densitometer using a two-wavelength, dual-beam technique was developed. Tests were performed on dry steam flows with this technique, which uses two narrow bandwidths of infrared light in the region of 0.9 to 3.0 μm. One wavelength is absorbed by steam, while the other is not. The latter wavelength is used to account for nonabsorptive light losses. In addition to the beam that traverses the steam flow, a reference beam that does not traverse the flow allows the light source to be monitored. The theory of the device is presented, along with a description of the components and of the system's operation. Test results are also presented

Avoiding steam-bubble-collapse-induced water hammers in piping systems

International Nuclear Information System (INIS)

Chou, Y.; Griffith, P.

1989-10-01

In terms of the frequency of occurrence, steam bubble collapse in subcooled water is the dominant initiating mechanism for water hammer events in nuclear power plants. Water hammer due to steam bubble collapse occurs when water slug forms in stratified horizontal flow, or when steam bubble is trapped at the end of the pipe. These types of water hammer events have been studied experimentally and analytically in order to develop stability maps showing those combinations of filling velocities and liquid subcooling that cause water hammer and those which don't. In developing the stability maps, experiments with different piping orientations were performed in a low pressure laboratory apparatus. Details of these experiments are described, including piping arrangement, test procedures, and test results. Visual tests using a transparent Lexan pipe are also performed to study the flow regimes accompanying the water hammer events. All analytical models were tested by comparison with the corresponding experimental results. Based on these models, and step-by-step approach for each flow geometry is presented for plant designers and engineers to follow in avoiding water hammer induced by steam bubble collapse when admitting cold water into pipes filled with steam. 37 refs., 54 figs., 2 tabs

Modeling sustainability in renewable energy supply chain systems